2024-03-28T16:25:11Zhttps://vtechworks.lib.vt.edu/server/oai/requestoai:vtechworks.lib.vt.edu:10919/1119962023-04-28T13:05:17Zcom_10919_5com_10919_25799com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_23765com_10919_24261com_10919_23261com_10919_24263com_10919_91912com_10919_23198col_10919_70873col_10919_24286col_10919_24342col_10919_24353col_10919_24343col_10919_23262col_10919_24345col_10919_91916
Histotripsy Ablation in Preclinical Animal Models of Cancer and Spontaneous Tumors in Veterinary Patients: A Review
Hendricks-Wenger, Alissa
Arnold, Lauren
Gannon, Jessica
Simon, Alex
Singh, Neha
Sheppard, Hannah
Nagai-Singer, Margaret A.
Imran, Khan Mohammed
Lee, Kiho
Clark-Deener, Sherrie
Byron, Christopher R.
Edwards, Michael R.
Larson, Martha M.
Rossmeisl, John H.
Coutermarsh-Ott, Sheryl
Eden, Kristin
Dervisis, Nikolaos G.
Klahn, Shawna L.
Tuohy, Joanne L.
Allen, Irving C.
Vlaisavljevich, Eli
Medical imaging
medical transducers
system and device design
therapeutics
CAVITATIONAL ULTRASOUND THERAPY
HEPATOCELLULAR-CARCINOMA
COMPARATIVE BIOLOGY
TISSUE STIFFNESS
VX-2 TUMOR
LIVER
DOGS
OSTEOSARCOMA
FREQUENCY
PIGS
Cancer
New therapeutic strategies are direly needed in the fight against cancer. Over the last decade, several tumor ablation strategies have emerged as stand-alone or combination therapies. Histotripsy is the first completely noninvasive, nonthermal, and nonionizing tumor ablation method. Histotripsy can produce consistent and rapid ablations, even near critical structures. Additional benefits include real-time image guidance, high precision, and the ability to treat tumors of any predetermined size and shape. Unfortunately, the lack of clinically and physiologically relevant preclinical cancer models is often a significant limitation with all focal tumor ablation strategies. The majority of studies testing histotripsy for cancer treatment have focused on small animal models, which have been critical in moving this field forward and will continue to be essential for providing mechanistic insight. While these small animal models have notable translational value, there are significant limitations in terms of scale and anatomical relevance. To address these limitations, a diverse range of large animal models and spontaneous tumor studies in veterinary patients have emerged to complement existing rodent models. These models and veterinary patients are excellent at providing realistic avenues for developing and testing histotripsy devices and techniques designed for future use in human patients. Here, we provide a review of animal models used in preclinical histotripsy studies and compare histotripsy ablation in these models using a series of original case reports across a broad spectrum of preclinical animal models and spontaneous tumors in veterinary patients.
2022-09-26
2022-09-26
2021-09-03
2022-09-23
Article - Refereed
0885-3010
http://hdl.handle.net/10919/111996
https://doi.org/10.1109/TUFFC.2021.3110083
69
1
Vlaisavljevich, Eli [0000-0002-4097-6257]
Larson, Martha [0000-0003-4229-5866]
Clark-Deener, Sherrie [0000-0002-6620-0625]
Allen, Irving [0000-0001-9573-5250]
Dervisis, Nikolaos [0000-0003-2869-1483]
Eden, Kristin [0000-0001-5309-5830]
34478363
1525-8955
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000736741000005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
IEEE
oai:vtechworks.lib.vt.edu:10919/1140252023-03-03T16:00:13Zcom_10919_5com_10919_25799com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_23765com_10919_23261com_10919_24263com_10919_91912com_10919_23198col_10919_70873col_10919_24286col_10919_24342col_10919_24353col_10919_23262col_10919_24345col_10919_91916
Histotripsy Ablation of Bone Tumors: Feasibility Study in Excised Canine Osteosarcoma Tumors
Arnold, Lauren
Hendricks-Wenger, Alissa
Coutermarsh-Ott, Sheryl
Gannon, Jessica
Hay, Alayna N.
Dervisis, Nikolaos G.
Klahn, Shawna L.
Allen, Irving C.
Tuohy, Joanne L.
Vlaisavljevich, Eli
Histotripsy
Focused ultrasound
Osteosarcoma
Bone
Tumors
Ablation
Osteosarcoma (OS) is a primary bone tumor affecting both dogs and humans. Histotripsy is a non-thermal, non-invasive focused ultrasound method using controlled acoustic cavitation to mechanically disintegrate tissue. In this study, we investigated the feasibility of treating primary OS tumors with histotripsy using a 500-kHz transducer on excised canine OS samples harvested after surgery at the Veterinary Teaching Hospital at Virginia Tech. Samples were embedded in gelatin tissue phantoms and treated with the 500-kHz histotripsy system using one- or two-cycle pulses at a pulse repetition frequency of 250 Hz and a dosage of 4000 pulses/point. Separate experiments also assessed histotripsy effects on normal canine bone and nerve using the same pulsing parameters. After treatment, histopathological evaluation of the samples was completed. To determine the feasibility of treating OS through intact skin/soft tissue, additional histotripsy experiments assessed OS with overlying tissues. Generation of bubble clouds was achieved at the focus in all tumor samples at peak negative pressures of 26.2 ± 4.5 MPa. Histopathology revealed effective cell ablation in treated areas for OS tumors, with no evidence of cell death or tissue damage in normal tissues. Treatment through tissue/skin resulted in generation of well-confined bubble clouds and ablation zones inside OS tumors. Results illustrate the feasibility of treating OS tumors with histotripsy.
CORRIGENDUM: The authors regret that errors were present in the above article. The legend for Figure 5 on page 3441 should read “Fig. 5. Normal, healthy, non-neoplastic bone was excised from amputated canine limbs and subjected to histology. No histological differences were noted between untreated (a: magnification 4 x, b: magnification 40 x) and treated samples (c: magnification 4 x, d: magnification 40 x).” Also, the final section heading on page 3439 should read “Histotripsy ablation of ex vivo bone and nerve specimens.” Finally, the reference after the last complete sentence on page 3437 is incomplete and should read “Focal pressure waveforms for the 500-kHz transducer were measured using a custom-built fiberoptic hydrophone (FOPH) in degassed water at the focal point of each transducer (Parsons et al. 2006).” The authors would like to apologise for any inconvenience caused.
2023-03-02
2023-03-02
2021-12
2023-03-01
Article - Refereed
0301-5629
S0301-5629(22)00119-3 (PII)
http://hdl.handle.net/10919/114025
https://doi.org/10.1016/j.ultrasmedbio.2021.08.004
47
12
Tuohy, Joanne [0000-0003-1516-3841]
Allen, Irving [0000-0001-9573-5250]
Dervisis, Nikolaos [0000-0003-2869-1483]
Vlaisavljevich, Eli [0000-0002-4097-6257]
35400542
1879-291X
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000810240600017&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
Elsevier
oai:vtechworks.lib.vt.edu:10919/187802023-12-11T11:08:07Zcom_10919_8195com_10919_25799com_10919_19035com_10919_5539com_10919_23765col_10919_18629col_10919_24290col_10919_24353
Network-based functional enrichment
Poirel, Christopher L.
Owens, Clifford C. III
Murali, T. M.
Computer Science
Institute for Critical Technology and Applied Science (ICTAS)
Background
Many methods have been developed to infer and reason about molecular interaction networks. These approaches often yield networks with hundreds or thousands of nodes and up to an order of magnitude more edges. It is often desirable to summarize the biological information in such networks. A very common approach is to use gene function enrichment analysis for this task. A major drawback of this method is that it ignores information about the edges in the network being analyzed, i.e., it treats the network simply as a set of genes. In this paper, we introduce a novel method for functional enrichment that explicitly takes network interactions into account.
Results
Our approach naturally generalizes Fisher’s exact test, a gene set-based technique. Given a function of interest, we compute the subgraph of the network induced by genes annotated to this function. We use the sequence of sizes of the connected components of this sub-network to estimate its connectivity. We estimate the statistical significance of the connectivity empirically by a permutation test. We present three applications of our method: i) determine which functions are enriched in a given network, ii) given a network and an interesting sub-network of genes within that network, determine which functions are enriched in the sub-network, and iii) given two networks, determine the functions for which the connectivity improves when we merge the second network into the first. Through these applications, we show that our approach is a natural alternative to network clustering algorithms.
Conclusions
We presented a novel approach to functional enrichment that takes into account the pairwise relationships among genes annotated by a particular function. Each of the three applications discovers highly relevant functions. We used our methods to study biological data from three different organisms. Our results demonstrate the wide applicability of our methods. Our algorithms are implemented in C++ and are freely available under the GNU General Public License at our supplementary website. Additionally, all our input data and results are available at http://bioinformatics.cs.vt.edu/~murali/supplements/2011-incob-nbe/.
2012-08-24
2012-08-24
2011-11-30
2012-08-24
Article - Refereed
BMC Bioinformatics. 2011 Nov 30;12(Suppl 13):S14
http://hdl.handle.net/10919/18780
https://doi.org/10.1186/1471-2105-12-S13-S14
en
http://creativecommons.org/licenses/by/4.0/
Christopher L Poirel et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1069582021-12-14T08:43:17Zcom_10919_23765com_10919_23261com_10919_5539col_10919_24353col_10919_23262
A study on interfacial behaviors of epoxy/graphene oxide derived from pitch-based graphite fibers
Kim, Seong-Hwang
Zhang, Yinhang
Lee, Jong-Hoon
Lee, Seul-Yi
Kim, Yeong-Hun
Rhee, Kyong Yop
Park, Soo-Jin
polymer-matrix composites
physical proper-ties
wettability
fracture toughness
Graphene oxide (GO) is a versatile material with inherent unique properties that can be used in a wide range of applications. GO is produced from graphitic materials including graphite, and its properties can depend on the nature of stacking in the graphene structures. In this study, GO was prepared from pitch-based graphite fibers via the modified Hummer's method and subsequently incorporated into an epoxy matrix to obtain grapheneloaded nanocomposites (EP/GO). Presented experimental results revealed that the addition of 0.6 wt% GO yielded an similar to 110% increase in the fracture toughness. The corresponding fracture energies as well as the flexural strengths and flexural modulus exhibited similar trends to the fracture toughness. The thermophysical properties of the EP/GO, to further demonstrate the reinforcing effectiveness of GO, were also observed. Collectively, these results indicate that GO investigated in the study can be a viable reinforcement candidate to develop next-generation nanocomposites with multifunctional properties.
2021-12-13
2021-12-13
2021-11-12
Article - Refereed
2191-9089
http://hdl.handle.net/10919/106958
https://doi.org/10.1515/ntrev-2021-0111
10
1
2191-9097
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/874262023-04-18T18:48:37Zcom_10919_5com_10919_25799com_10919_24209com_10919_5553com_10919_23765com_10919_24369com_10919_5539col_10919_70873col_10919_24267col_10919_24353col_10919_24370
Abundance and Speciation of Surface Oxygen on Nanosized Platinum Catalysts and Effect on Catalytic Activity
Serra-Maia, Rui
Winkler, Christopher
Murayama, Mitsuhiro
Tranhuu, Kevin
Michel, F. Marc
Geosciences
Institute for Critical Technology and Applied Science
Materials Science and Engineering
Oxygen at the surface of nanosized platinum has a direct effect on catalytic activity of oxidation−reduction chemical reactions. However, the abundance and speciation of oxygen remain uncertain for platinum with different particle size and shape characteristics, which has hindered the development of fundamental property−activity relationships. We have characterized two commercially available platinum nanocatalysts known as Pt black and Pt nanopowder to evaluate the effects of synthesis and heating conditions on the physical and surface chemical properties, as well as on catalytic activity. Characterization using complementary electron microscopy, X-ray scattering, and spectroscopic methods showed that the larger average crystallite size of Pt nanopowder (23 nm) compared to Pt black (11 nm) corresponds with a 70% greater surface oxygen concentration. Heating the samples in air resulted in an increase in surface oxygen concentration for both nanocatalysts. Surface oxygen associated with platinum is in the form of chemisorbed oxygen, and no significant amounts of chemically bonded platinum oxide were found for any of the samples. The increase in surface oxygen abundance during heating depends on the initial size and surface oxygen content. Hydrogen peroxide decomposition rate measurements showed that larger particle size and higher surface chemisorbed oxygen correlate with enhanced catalytic activity. These results are particularly important for future studies that aim to relate the properties of platinum, or other metal nanocatalysts, with surface reactivity.
2019-02-04
2019-02-04
2018-06-18
2019-02-04
Article - Refereed
2574-0962
http://hdl.handle.net/10919/87426
https://doi.org/10.1021/acsaem.8b00474
1
Michel, Frederick [0000-0003-2817-980X]
2574-0962
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
oai:vtechworks.lib.vt.edu:10919/1114292023-11-29T19:07:28Zcom_10919_5com_10919_25799com_10919_5540com_10919_24259com_10919_5559com_10919_23765com_10919_24263com_10919_91912com_10919_23198col_10919_70873col_10919_71752col_10919_24342col_10919_24353col_10919_24345col_10919_91916
High intensity focused ultrasound for the treatment of solid tumors: a pilot study in canine cancer patients
Carroll, Jennifer
Coutermarsh-Ott, Sheryl
Klahn, Shawna L.
Tuohy, Joanne L.
Barry, Sabrina L.
Allen, Irving C.
Hay, Alayna N.
Ruth, Jeffrey
Dervisis, Nikolaos G.
Dog
High-intensity focused ultrasound
immunotherapy
thermal ablation
Rare Diseases
Cancer
Purpose: To investigate the safety, feasibility, and outcomes of High-Intensity Focused Ultrasound (HIFU) for the treatment of solid tumors in a spontaneous canine cancer model.
Methods: Dogs diagnosed with subcutaneous solid tumors were recruited, staged and pretreatment biopsies were obtained. A single HIFU treatment was delivered to result in partial tumor ablation using a commercially available HIFU unit. Tumors were resected 3-6 days post HIFU and samples obtained for histopathology and immunohistochemistry. Total RNA was isolated from paired pre and post treated FFPE tumor samples, and quantitative gene expression analysis was performed using the nCounter Canine IO Panel.
Results: A total of 20 dogs diagnosed with solid tumors were recruited and treated in the study. Tumors treated included Soft Tissue Sarcoma (<i>n</i> = 15), Mast Cell Tumor (<i>n</i> = 3), Osteosarcoma (<i>n</i> = 1), and Thyroid Carcinoma (<i>n</i> = 1). HIFU was well tolerated with only 1 dog experiencing a clinically significant adverse event. Pathology confirmed the presence of complete tissue ablation at the HIFU targeted site and immunohistochemistry indicated immune cell infiltration at the treated/untreated tumor border. Quantitative gene expression analysis indicated that 28 genes associated with T-cell activation were differentially expressed post-HIFU.
Conclusions: HIFU appears to be safe and feasible for the treatment of subcutaneous canine solid tumors, resulting in ablation of the targeted tissue. HIFU induced immunostimulatory changes, highlighting the canine cancer patient as an attractive model for studying the effects of focal ablation therapies on the tumor microenvironment.
2022-08-02
2022-08-02
2022-01
2022-08-02
Article - Refereed
0265-6736
http://hdl.handle.net/10919/111429
https://doi.org/10.1080/02656736.2022.2097323
39
1
Dervisis, Nikolaos [0000-0003-2869-1483]
35848421
1464-5157
en
https://www.ncbi.nlm.nih.gov/pubmed/35848421
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Taylor & Francis
oai:vtechworks.lib.vt.edu:10919/1119882022-09-24T07:14:13Zcom_10919_5com_10919_25799com_10919_24216com_10919_5539com_10919_23765com_10919_91912com_10919_23198col_10919_70873col_10919_24286col_10919_24353col_10919_91916
Particle-mediated Histotripsy for the Targeted Treatment of Intraluminal Biofilms in Catheter-based Medical Devices
Childers, Christopher
Edsall, Connor
Mehochko, Isabelle
Mustafa, Waleed
Yuksel Durmaz, Yasemin
Klibanov, Alexander L.
Rao, Jayasimha
Vlaisavljevich, Eli
Biomedical Imaging
Bioengineering
Infection
Objective: This paper is an initial work towards developing particle-mediated histotripsy (PMH) as a novel method of treating catheter-based medical device (CBMD) intraluminal biofilms.
Impact Statement: CBMDs commonly become infected with bacterial biofilms leading to medical device failure, infection, and adverse patient outcomes.
Introduction: Histotripsy is a noninvasive focused ultrasound ablation method that was recently proposed as a novel method to remove intraluminal biofilms. Here, we explore the potential of combining histotripsy with acoustically active particles to develop a PMH approach that can noninvasively remove biofilms without the need for high acoustic pressures or real-time image guidance for targeting.
Methods: Histotripsy cavitation thresholds in catheters containing either gas-filled microbubbles (MBs) or fluid-filled nanocones (NCs) were determined. The ability of these particles to sustain cavitation over multiple ultrasound pulses was tested after a series of histotripsy exposures. Next, the ability of PMH to generate selective intraluminal cavitation without generating extraluminal cavitation was tested. Finally, the biofilm ablation and bactericidal capabilities of PMH were tested using both MBs and NCs.
Results: PMH significantly reduced the histotripsy cavitation threshold, allowing for selective luminal cavitation for both MBs and NCs. Results further showed PMH successfully removed intraluminal biofilms in Tygon catheters. Finally, results from bactericidal experiments showed minimal reduction in bacteria viability.
Conclusion: The results of this study demonstrate the potential for PMH to provide a new modality for removing bacterial biofilms from CBMDs and suggest that additional work is warranted to develop histotripsy and PMH for treatment of CBMD intraluminal biofilms.
2022-09-23
2022-09-23
2022-08-09
2022-09-23
Article - Refereed
2765-8031
http://hdl.handle.net/10919/111988
https://doi.org/10.34133/2022/9826279
2022
Vlaisavljevich, Eli [0000-0002-4097-6257]
Rao, Jayasimha [0000-0002-0133-2862]
2765-8031
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
American Association for the Advancement of Science (AAAS)
oai:vtechworks.lib.vt.edu:10919/943372020-10-15T17:45:07Zcom_10919_23765col_10919_24353
Nanotechnology in the real world: Redeveloping the nanomaterial consumer products inventory
Vance, Marina
Kuiken, Todd
Vejerano, Eric P.
McGinnis, Sean
Hochella, Michael F. Jr.
Rejeski, David
Hull, Matthew S.
consumer products
database
inventory
nanoinformatics
nanomaterials
To document the marketing and distribution of nano-enabled products into the commercial marketplace, the Woodrow Wilson International Center for Scholars and the Project on Emerging Nanotechnologies created the Nanotechnology Consumer Products Inventory (CPI) in 2005. The objective of this present work is to redevelop the CPI by leading a research effort to increase the usefulness and reliability of this inventory. We created eight new descriptors for consumer products, including information pertaining to the nanomaterials contained in each product. The project was motivated by the recognition that a diverse group of stakeholders from academia, industry, and state/federal government had become highly dependent on the inventory as an important resource and bellweather of the pervasiveness of nanotechnology in society. We interviewed 68 nanotechnology experts to assess key information needs. Their answers guided inventory modifications by providing a clear conceptual framework best suited for user expectations. The revised inventory was released in October 2013. It currently lists 1814 consumer products from 622 companies in 32 countries. The Health and Fitness category contains the most products (762, or 42% of the total). Silver is the most frequently used nanomaterial (435 products, or 24%); however, 49% of the products (889) included in the CPI do not provide the composition of the nanomaterial used in them. About 29% of the CPI (528 products) contain nanomaterials suspended in a variety of liquid media and dermal contact is the most likely exposure scenario from their use. The majority (1288 products, or 71%) of the products do not present enough supporting information to corroborate the claim that nanomaterials are used. The modified CPI has enabled crowdsourcing capabilities, which allow users to suggest edits to any entry and permits researchers to upload new findings ranging from human and environmental exposure data to complete life cycle assessments. There are inherent limitations to this type of database, but these modifications to the inventory addressed the majority of criticisms raised in published literature and in surveys of nanotechnology stakeholders and experts. The development of standardized methods and metrics for nanomaterial characterization and labelling in consumer products can lead to greater understanding between the key stakeholders in nanotechnology, especially consumers, researchers, regulators, and industry.
2019-10-03
2019-10-03
2015
Article - Refereed
http://hdl.handle.net/10919/94337
https://doi.org/10.1515/nano.bjneah.6.181
6
en_US
http://creativecommons.org/licenses/by/2.0/
Creative Commons Attribution 2.0 Generic
Beilstein-Institut
oai:vtechworks.lib.vt.edu:10919/566772023-05-18T13:28:48Zcom_10919_24227com_10919_5532com_10919_23765com_10919_91436com_10919_79468com_10919_78628col_10919_24302col_10919_24353col_10919_97229col_10919_79481
Overcoming Biomass Recalcitrance by Combining Genetically Modified Switchgrass and Cellulose Solvent-Based Lignocellulose Pretreatment
Sathitsuksanoh, Noppadon
Xu, Bin
Zhao, Bingyu Y.
Zhang, Y. H. Percival
Biological Systems Engineering
Institute for Critical Technology and Applied Science
School of Plant and Environmental Sciences
Accessibility
Biofuel production
Corn stover
Dilute-acid pretreatment
Enzymatic-hydrolysis
Ethanol
Fermentable sugar yields
Fractionation
Lignin modification
Saccharification
Decreasing lignin content of plant biomass by genetic engineering is believed to mitigate biomass recalcitrance and improve saccharification efficiency of plant biomass. In this study, we compared two different pretreatment methods (i.e., dilute acid and cellulose solvent) on transgenic plant biomass samples having different lignin contents and investigated biomass saccharification efficiency. Without pretreatment, no correlation was observed between lignin contents of plant biomass and saccharification efficiency. After dilute acid pretreatment, a strong negative correlation between lignin content of plant samples and overall glucose release was observed, wherein the highest overall enzymatic glucan digestibility was 70% for the low-lignin sample. After cellulose solvent- and organic solvent-based lignocellulose fractionation pretreatment, there was no strong correlation between lignin contents and high saccharification efficiencies obtained (i.e., 80-90%). These results suggest that the importance of decreasing lignin content in plant biomass to saccharification was largely dependent on pretreatment choice and conditions.
2015-10-01
2015-10-01
2013-09-27
Article - Refereed
Sathitsuksanoh, N., Xu, B., Zhao, B., & Zhang, Y. H. P. (2013). Overcoming Biomass Recalcitrance by Combining Genetically Modified Switchgrass and Cellulose Solvent-Based Lignocellulose Pretreatment. Plos One, 8(9), e73523. doi: 10.1371/journal.pone.0073523
1932-6203
http://hdl.handle.net/10919/56677
https://doi.org/10.1371/journal.pone.0073523
8
9
en
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
oai:vtechworks.lib.vt.edu:10919/479822023-06-14T17:01:29Zcom_10919_78629com_10919_78628com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_24233com_10919_5532com_10919_23765com_10919_23274col_10919_78630col_10919_24286col_10919_24342col_10919_24308col_10919_24353col_10919_23275
Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis
Salmanzadeh, Alireza
Kittur, Harsha
Sano, Michael B.
Roberts, Paul C.
Schmelz, Eva M.
Davalos, Rafael V.
Biomedical Engineering and Mechanics
Biomedical Sciences and Pathobiology
Human Nutrition, Foods, and Exercise
Institute for Critical Technology and Applied Science
School of Biomedical Engineering and Sciences
Force microscopy
Breast cancer
Dielectrics
Stem-cells
Separation
Blood
Electrorotation
Biomarkers
Frequency
Membranes
Biochemical research methods
Biophysics
Nanoscience & nanotechnology
Physics, fluids & plasmas
Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3699973] Actual pdf downloaded from NCBI.
2014-05-14
2014-05-14
2012-06-01
2014-05-09
Article - Refereed
Salmanzadeh, A.; Kittur, H.; Sano, M. B.; Roberts, P. C.; Schmelz, E. M.; Davalos, R. V., "Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis," Biomicrofluidics 6, 024104 (2012); http://dx.doi.org/10.1063/1.3699973
1932-1058
http://hdl.handle.net/10919/47982
http://scitation.aip.org/content/aip/journal/bmf/6/2/10.1063/1.3699973
https://doi.org/10.1063/1.3699973
en
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
American Institute of Physics
oai:vtechworks.lib.vt.edu:10919/888872022-02-26T22:17:38Zcom_10919_23829com_10919_5553com_10919_19035com_10919_5539com_10919_23765com_10919_24213col_10919_23830col_10919_24290col_10919_24353col_10919_24334
XTALKDB: a database of signaling pathway crosstalk
Sam, Sarah A.
Teel, Joelle
Tegge, Allison N.
Bharadwaj, Aditya
Murali, T. M.
Biological Sciences
Computer Science
Statistics
Institute for Critical Technology and Applied Science
notch
networks
cancer
resource
hedgehog
annotation
update
Analysis of signaling pathways and their crosstalk is a cornerstone of systems biology. Thousands of papers have been published on these topics. Surprisingly, there is no database that carefully and explicitly documents crosstalk between specific pairs of signaling pathways. We have developed XTALKDB (http://www.xtalkdb.org) to fill this very important gap. XTALKDB contains curated information for 650 pairs of pathways from over 1600 publications. In addition, the database reports the molecular components (e.g. proteins, hormones, microRNAs) that mediate crosstalk between a pair of pathways and the species and tissue in which the crosstalk was observed. The XTALKDB website provides an easy-to- use interface for scientists to browse crosstalk information by querying one or more pathways or molecules of interest.
2019-04-11
2019-04-11
2017-01-04
Article - Refereed
0305-1048
http://hdl.handle.net/10919/88887
https://doi.org/10.1093/nar/gkw1037
45
D1
27899583
1362-4962
en_US
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1007742020-11-24T17:46:52Zcom_10919_19035com_10919_5539com_10919_23765col_10919_24290col_10919_24353
Connectivity Measures for Signaling Pathway Topologies
Franzese, Nicholas
Groce, Adam
Murali, T. M.
Ritz, Anna
Characterizing cellular responses to different extrinsic signals is an active area of research, and curated pathway databases describe these complex signaling reactions. Here, we revisit a fundamental question in signaling pathway analysis: are two molecules “connected” in a network? This question is the first step towards understanding the potential influence of molecules in a pathway, and the answer depends on the choice of modeling framework. We examined the connectivity of Reactome signaling pathways using four different pathway representations. We find that Reactome is very well connected as a graph, moderately well connected as a compound graph or bipartite graph, and poorly connected as a hypergraph (which captures many-to-many relationships in reaction networks). We present a novel relaxation of hypergraph connectivity that iteratively increases connectivity from a node while preserving the hypergraph topology. This measure, B-relaxation distance, provides a parameterized transition between hypergraph connectivity and graph connectivity. B-relaxation distance is sensitive to the presence of small molecules that participate in many functionally unrelated reactions in the network. We also define a score that quantifies one pathway’s downstream influence on another, which can be calculated as B-relaxation distance gradually relaxes the connectivity constraint in hypergraphs. Computing this score across all pairs of 34 Reactome pathways reveals two case studies of pathway influence, and we describe the specific reactions that contribute to the large influence score. Our method lays the groundwork for other generalizations of graph-theoretic concepts to hypergraphs in order to facilitate signaling pathway analysis.
2020-11-03
2020-11-03
2019-03-30
Article
http://hdl.handle.net/10919/100774
https://doi.org/10.1101/593913
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Virginia Tech
oai:vtechworks.lib.vt.edu:10919/248512023-08-30T19:29:19Zcom_10919_8195com_10919_25799com_10919_23765com_10919_79468com_10919_78628col_10919_78882col_10919_24353col_10919_79481
Membranes in Lithium Ion Batteries
Yang, Min
Hou, Junbo
lithium ion battery
Li ion conductor
separator
ceramic
polymer
Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.
2014-01-15
2014-01-15
2012-07-04
2014-01-06
Article - Refereed
Yang, Min; Hou, Junbo. 2012. "Membranes in Lithium Ion Batteries." Membranes 2012, 2(3), 367-383; doi:10.3390/membranes2030367.
2077-0375
http://hdl.handle.net/10919/24851
http://www.mdpi.com/2077-0375/2/3/367
https://doi.org/10.3390/membranes2030367
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/1109012023-08-30T19:29:23Zcom_10919_8195com_10919_25799com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_23765com_10919_24263col_10919_78882col_10919_24286col_10919_24342col_10919_24353col_10919_24345
High-Frequency Irreversible Electroporation (H-FIRE) Induced Blood-Brain Barrier Disruption Is Mediated by Cytoskeletal Remodeling and Changes in Tight Junction Protein Regulation
Partridge, Brittanie R.
Kani, Yukitaka
Lorenzo, Melvin F.
Campelo, Sabrina N.
Allen, Irving C.
Hinckley, Jonathan
Hsu, Fang-Chi
Verbridge, Scott S.
Robertson, John L.
Davalos, Rafael V.
Rossmeisl, John H.
Glioblastoma is the deadliest malignant brain tumor. Its location behind the blood–brain barrier (BBB) presents a therapeutic challenge by preventing effective delivery of most chemotherapeutics. H-FIRE is a novel tumor ablation method that transiently disrupts the BBB through currently unknown mechanisms. We hypothesized that H-FIRE mediated BBB disruption (BBBD) occurs via cytoskeletal remodeling and alterations in tight junction (TJ) protein regulation. Intracranial H-FIRE was delivered to Fischer rats prior to sacrifice at 1-, 24-, 48-, 72-, and 96 h post-treatment. Cytoskeletal proteins and native and ubiquitinated TJ proteins (TJP) were evaluated using immunoprecipitation, Western blotting, and gene-expression arrays on treated and sham control brain lysates. Cytoskeletal and TJ protein expression were further evaluated with immunofluorescent microscopy. A decrease in the F/G-actin ratio, decreased TJP concentrations, and increased ubiquitination of TJP were observed 1–48 h post-H-FIRE compared to sham controls. By 72–96 h, cytoskeletal and TJP expression recovered to pretreatment levels, temporally corresponding with increased claudin-5 and zonula occludens-1 gene expression. Ingenuity pathway analysis revealed significant dysregulation of claudin genes, centered around claudin-6 in H-FIRE treated rats. In conclusion, H-FIRE is capable of permeating the BBB in a spatiotemporal manner via cytoskeletal-mediated TJP modulation. This minimally invasive technology presents with applications for localized and long-lived enhanced intracranial drug delivery.
2022-06-23
2022-06-23
2022-06-11
2022-06-23
Article - Refereed
Partridge, B.R.; Kani, Y.; Lorenzo, M.F.; Campelo, S.N.; Allen, I.C.; Hinckley, J.; Hsu, F.-C.; Verbridge, S.S.; Robertson, J.L.; Davalos, R.V.; Rossmeisl, J.H. High-Frequency Irreversible Electroporation (H-FIRE) Induced Blood-Brain Barrier Disruption Is Mediated by Cytoskeletal Remodeling and Changes in Tight Junction Protein Regulation. Biomedicines 2022, 10, 1384.
http://hdl.handle.net/10919/110901
https://doi.org/10.3390/biomedicines10061384
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/736222024-03-13T14:09:53Zcom_10919_5com_10919_25799com_10919_23829com_10919_5553com_10919_19035com_10919_5539com_10919_25796com_10919_23765col_10919_70873col_10919_23830col_10919_24290col_10919_25797col_10919_24353
Experimental testing of a new integrated model of the budding yeast Start transition
Adames, Neil R.
Schuck, P. Logan
Chen, Katherine C.
Murali, T. M.
Tyson, John J.
Peccoud, Jean
Biological Sciences
Computer Science
Fralin Life Sciences Institute
Institute for Critical Technology and Applied Science
Cell Biology
CELL-CYCLE START
SYSTEMS-LEVEL FEEDBACK
CDC28 PROTEIN-KINASE
SACCHAROMYCES-CEREVISIAE
TRANSCRIPTION FACTOR
SIZE-CONTROL
G1 CYCLINS
DNA-REPLICATION
S-PHASE
CLN3-CDC28 KINASE
The cell cycle is composed of bistable molecular switches that govern the transitions between gap phases (G1 and G2) and the phases in which DNA is replicated (S) and partitioned between daughter cells (M). Many molecular details of the budding yeast G1–S transition (Start) have been elucidated in recent years, especially with regard to its switch-like behavior due to positive feedback mechanisms. These results led us to reevaluate and expand a previous mathematical model of the yeast cell cycle. The new model incorporates Whi3 inhibition of Cln3 activity, Whi5 inhibition of SBF and MBF transcription factors, and feedback inhibition of Whi5 by G1–S cyclins. We tested the accuracy of the model by simulating various mutants not described in the literature. We then constructed these novel mutant strains and compared their observed phenotypes to the model’s simulations. The experimental results reported here led to further changes of the model, which will be fully described in a later article. Our study demonstrates the advantages of combining model design, simulation, and testing in a coordinated effort to better understand a complex biological network.
2016-12-09
2016-12-09
2015-11-05
Article - Refereed
1059-1524
http://hdl.handle.net/10919/73622
https://doi.org/10.1091/mbc.E15-06-0358
26
22
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000366324900013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by-nc-sa/3.0/
Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported
American Society for Cell Biology
oai:vtechworks.lib.vt.edu:10919/1165712023-10-31T07:13:35Zcom_10919_8195com_10919_25799com_10919_23765com_10919_23261com_10919_5539com_10919_23274col_10919_18629col_10919_24353col_10919_23262col_10919_23275
Engineered live bacteria as disease detection and diagnosis tools
Tanniche, Imen
Behkam, Bahareh
Sensitive and minimally invasive medical diagnostics are essential to the early detection of diseases, monitoring their progression and response to treatment. Engineered bacteria as live sensors are being developed as a new class of biosensors for sensitive, robust, noninvasive, and in situ detection of disease onset at low cost. Akin to microrobotic systems, a combination of simple genetic rules, basic logic gates, and complex synthetic bioengineering principles are used to program bacterial vectors as living machines for detecting biomarkers of diseases, some of which cannot be detected with other sensing technologies. Bacterial whole-cell biosensors (BWCBs) can have wide-ranging functions from detection only, to detection and recording, to closed-loop detection-regulated treatment. In this review article, we first summarize the unique benefits of bacteria as living sensors. We then describe the different bacteria-based diagnosis approaches and provide examples of diagnosing various diseases and disorders. We also discuss the use of bacteria as imaging vectors for disease detection and image-guided surgery. We conclude by highlighting current challenges and opportunities for further exploration toward clinical translation of these bacteria-based systems.
2023-10-30
2023-10-30
2023-10-24
2023-10-29
Article - Refereed
Journal of Biological Engineering. 2023 Oct 24;17(1):65
http://hdl.handle.net/10919/116571
https://doi.org/10.1186/s13036-023-00379-z
en
http://creativecommons.org/licenses/by/4.0/
BioMed Central Ltd., part of Springer Nature
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/649662023-11-29T12:34:34Zcom_10919_23747com_10919_5539com_10919_23765com_10919_23939com_10919_5557col_10919_23748col_10919_24353col_10919_24329
Preparation and evaluation of nanocellulose-gold nanoparticle nanocomposites for SERS applications
Wei, Haoran
Rodriguez, Katia
Renneckar, Scott
Leng, Weinan
Vikesland, Peter J.
Civil and Environmental Engineering
Institute of Critical Technology and Applied Science
Duke University. Center for the Environmental Implications of Nanotechnology
Sustainable Biomaterials
Nanocellulose is of research interest due to its extraordinary optical, thermal, and mechanical properties. The incorporation of guest nanoparticles into nanocellulose substrates enables production of novel nanocomposites with a broad range of applications. In this study, gold nanoparticle/bacterial cellulose (AuNP/BC) nanocomposites were prepared and evaluated for their applicability as surface-enhanced Raman scattering (SERS) substrates. The nanocomposites were prepared by citrate mediated in situ reduction of Au3+ in the presence of a BC hydrogel at 303 K. Both the size and morphology of the AuNPs were functions of the HAuCl4 and citrate concentrations. At high HAuCl4 concentrations, Au nanoplates form within the nanocomposites and are responsible for high SERS enhancements. At lower HAuCl4 concentrations, uniform nanospheres form and the SERS enhancement is dependent on the nanosphere size. The time-resolved increase in the SERS signal was probed as a function of drying time with SERS ‘hot-spots’ primarily forming in the final minutes of nanocomposite drying. The application of the AuNP/BC nanocomposites for detection of the SERS active dyes MGITC and R6G as well as the environmental contaminant atrazine is illustrated as is its use under low and high pH conditions. The results indicate the broad applicability of this nanocomposite for analyte detection.
2016-03-18
2016-03-18
2015-06-09
2016-03-17
Article - Refereed
Wei, H., Rodriguez, K., Renneckar, S., Leng, W., & Vikesland, P. J. (2015). Preparation and evaluation of nanocellulose-gold nanoparticle nanocomposites for SERS applications. Analyst, 140(16), 5640-5649. doi:10.1039/C5AN00606F
0003-2654
2015_Wei_Preparation_and_evaluation_of_nanocel.pdf
Preparation_evaluation_supp_info.pdf
CBET 1236005
EF-0830093
http://hdl.handle.net/10919/64966
https://doi.org/10.1039/C5AN00606F
140
16
en
http://creativecommons.org/licenses/by-nc/3.0/
Creative Commons Attribution-NonCommercial 3.0 Unported
The Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/469832023-12-11T11:08:39Zcom_10919_8195com_10919_25799com_10919_23829com_10919_5553com_10919_19035com_10919_5539com_10919_25796com_10919_23765col_10919_18629col_10919_23830col_10919_24290col_10919_25797col_10919_24353
Computational approaches for discovery of common immunomodulators in fungal infections: towards broad-spectrum immunotherapeutic interventions
Kidane, Yared H.
Lawrence, Christopher B.
Murali, T. M.
Biological Sciences
Computer Science
Fralin Life Sciences Institute
Institute for Critical Technology and Applied Science
Background
Fungi are the second most abundant type of human pathogens. Invasive fungal pathogens are leading causes of life-threatening infections in clinical settings. Toxicity to the host and drug-resistance are two major deleterious issues associated with existing antifungal agents. Increasing a host’s tolerance and/or immunity to fungal pathogens has potential to alleviate these problems. A host’s tolerance may be improved by modulating the immune system such that it responds more rapidly and robustly in all facets, ranging from the recognition of pathogens to their clearance from the host. An understanding of biological processes and genes that are perturbed during attempted fungal exposure, colonization, and/or invasion will help guide the identification of endogenous immunomodulators and/or small molecules that activate host-immune responses such as specialized adjuvants.
Results
In this study, we present computational techniques and approaches using publicly available transcriptional data sets, to predict immunomodulators that may act against multiple fungal pathogens. Our study analyzed data sets derived from host cells exposed to five fungal pathogens, namely, Alternaria alternata, Aspergillus fumigatus, Candida albicans, Pneumocystis jirovecii, and Stachybotrys chartarum. We observed statistically significant associations between host responses to A. fumigatus and C. albicans. Our analysis identified biological processes that were consistently perturbed by these two pathogens. These processes contained both immune response-inducing genes such as MALT1, SERPINE1, ICAM1, and IL8, and immune response-repressing genes such as DUSP8, DUSP6, and SPRED2. We hypothesize that these genes belong to a pool of common immunomodulators that can potentially be activated or suppressed (agonized or antagonized) in order to render the host more tolerant to infections caused by A. fumigatus and C. albicans.
Conclusions
Our computational approaches and methodologies described here can now be applied to newly generated or expanded data sets for further elucidation of additional drug targets. Moreover, identified immunomodulators may be used to generate experimentally testable hypotheses that could help in the discovery of broad-spectrum immunotherapeutic interventions. All of our results are available at the following supplementary website: http://bioinformatics.cs.vt.edu/~murali/supplements/2013-kidane-bmc
2014-04-05
2014-04-05
2013-10-07
2014-04-05
Article - Refereed
BMC Microbiology. 2013 Oct 07;13(1):224
http://hdl.handle.net/10919/46983
https://doi.org/10.1186/1471-2180-13-224
en
http://creativecommons.org/licenses/by/4.0/
Yared H Kidane et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/854072022-02-26T15:58:40Zcom_10919_78629com_10919_78628com_10919_112356com_10919_23261com_10919_5539com_10919_24209com_10919_5553com_10919_23765col_10919_78630col_10919_112358col_10919_24267col_10919_24353
Discovery and ramifications of incidental Magnéli phase generation and release from industrial coal-burning
Yang, Yi
Chen, Bo
Hower, James C.
Schindler, Michael
Winkler, Christopher
Brandt, Jessica E.
Di Giulio, Richard T.
Ge, Jianping
Liu, Min
Fu, Yuhao
Zhang, Lijun
Chen, Yu-ru
Priya, Shashank
Hochella, Michael F. Jr.
Center for Energy Harvesting Materials and Systems (CEHMS)
Geosciences
Institute for Critical Technology and Applied Science
Coal, as one of the most economic and abundant energy sources, remains the leading fuel for producing electricity worldwide. Yet, burning coal produces more global warming CO2 relative to all other fossil fuels, and it is a major contributor to atmospheric particulate matter known to have a deleterious respiratory and cardiovascular impact in humans, especially in China and India. Here we have discovered that burning coal also produces large quantities of otherwise rare Magneli phases (Ti; x; O2x–1 with 4 ≤ x ≤ 9) from TiO2 minerals naturally present in coal. This provides a new tracer for tracking solid-state emissions worldwide from industrial coal-burning. In its first toxicity testing, we have also shown that nanoscale Magneli phases have potential toxicity pathways that are not photoactive like TiO2 phases, but instead seem to be biologically active without photostimulation. In the future, these phases should be thoroughly tested for their toxicity in the human lung. Solid-state emissions from coal burning remain an environmental concern. Here, the authors have found that TiO2 minerals present in coal are converted into titanium suboxides during burning, and initial biotoxicity screening suggests that further testing is needed to look into human lung consequences.
2018-10-18
2018-10-18
2017-01-12
Article - Refereed
20411723
http://hdl.handle.net/10919/85407
https://doi.org/10.1038/s41467-017-00276-2
8
28790379
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Nature Publishing Group
oai:vtechworks.lib.vt.edu:10919/937202020-10-15T17:45:00Zcom_10919_23747com_10919_5539com_10919_23765col_10919_23748col_10919_24353
Aerosol microdroplets exhibit a stable pH gradient
Wei, Haoran
Vejerano, Eric P.
Leng, Weinan
Huang, Qishen
Willner, Marjorie R.
Marr, Linsey C.
Vikesland, Peter J.
Civil and Environmental Engineering
Institute for Critical Technology and Applied Science (ICTAS)
aerosol
droplet
pH
interface
SERS
Suspended aqueous aerosol droplets (< 50 mu m) are microreactors for many important atmospheric reactions. In droplets and other aquatic environments, pH is arguably the key parameter dictating chemical and biological processes. The nature of the droplet air/water interface has the potential to significantly alter droplet pH relative to bulk water. Historically, it has been challenging to measure the pH of individual droplets because of their inaccessibility to conventional pH probes. In this study, we scanned droplets containing 4-mercaptobenzoic acid-functionalized gold nanoparticle pH nanoprobes by 2D and 3D laser confocal Raman microscopy. Using surface-enhanced Raman scattering, we acquired the pH distribution inside approximately 20-mu m-diameter phosphate-buffered aerosol droplets and found that the pH in the core of a droplet is higher than that of bulk solution by up to 3.6 pH units. This finding suggests the accumulation of protons at the air/water interface and is consistent with recent thermodynamic model results. The existence of this pH shift was corroborated by the observation that a catalytic reaction that occurs only under basic conditions (i.e., dimerization of 4-aminothiophenol to produce dimercaptoazobenzene) occurs within the high pH core of a droplet, but not in bulk solution. Our nanoparticle probe enables pH quantification through the cross-section of an aerosol droplet, revealing a spatial gradient that has implications for acid-base-catalyzed atmospheric chemistry.
2019-09-16
2019-09-16
2018-07-10
Article - Refereed
0027-8424
http://hdl.handle.net/10919/93720
https://doi.org/10.1073/pnas.1720488115
115
28
29941550
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
oai:vtechworks.lib.vt.edu:10919/861582023-06-23T15:22:58Zcom_10919_8195com_10919_25799com_10919_23747com_10919_5539com_10919_23765com_10919_79468com_10919_78628col_10919_18629col_10919_23748col_10919_24353col_10919_79481
Nanomaterial enabled sensors for environmental contaminants
Willner, Marjorie R.
Vikesland, Peter J.
Civil and Environmental Engineering
Institute for Critical Technology and Applied Science
The need and desire to understand the environment, especially the quality of one’s local water and air, has continued to expand with the emergence of the digital age. The bottleneck in understanding the environment has switched from being able to store all of the data collected to collecting enough data on a broad range of contaminants of environmental concern. Nanomaterial enabled sensors represent a suite of technologies developed over the last 15 years for the highly specific and sensitive detection of environmental contaminants. With the promise of facile, low cost, field-deployable technology, the ability to quantitatively understand nature in a systematic way will soon be a reality. In this review, we first introduce nanosensor design before exploring the application of nanosensors for the detection of three classes of environmental contaminants: pesticides, heavy metals, and pathogens.
2018-11-26
2018-11-26
2018-11-22
2018-11-26
Article - Refereed
Journal of Nanobiotechnology. 2018 Nov 22;16(1):95
http://hdl.handle.net/10919/86158
https://doi.org/10.1186/s12951-018-0419-1
en
http://creativecommons.org/licenses/by/4.0/
The Author(s)
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/644692023-12-11T11:08:48Zcom_10919_8195com_10919_25799com_10919_19035com_10919_5539com_10919_23765col_10919_18629col_10919_24290col_10919_24353
Summarizing cellular responses as biological process networks
Lasher, Christopher D.
Rajagopalan, Padmavathy
Murali, T. M.
Computer Science
Institute for Critical Technology and Applied Science (ICTAS)
Background
Microarray experiments can simultaneously identify thousands of genes that show significant perturbation in expression between two experimental conditions. Response networks, computed through the integration of gene interaction networks with expression perturbation data, may themselves contain tens of thousands of interactions. Gene set enrichment has become standard for summarizing the results of these analyses in terms functionally coherent collections of genes such as biological processes. However, even these methods can yield hundreds of enriched functions that may overlap considerably.
Results
We describe a new technique called Markov chain Monte Carlo Biological Process Networks (MCMC-BPN) capable of reporting a highly non-redundant set of links between processes that describe the molecular interactions that are perturbed under a specific biological context. Each link in the BPN represents the perturbed interactions that serve as the interfaces between the two processes connected by the link. We apply MCMC-BPN to publicly available liver-related datasets to demonstrate that the networks formed by the most probable inter-process links reported by MCMC-BPN show high relevance to each biological condition. We show that MCMC-BPN’s ability to discern the few key links from in a very large solution space by comparing results from two other methods for detecting inter-process links.
Conclusions
MCMC-BPN is successful in using few inter-process links to explain as many of the perturbed gene-gene interactions as possible. Thereby, BPNs summarize the important biological trends within a response network by reporting a digestible number of inter-process links that can be explored in greater detail.
2016-01-19
2016-01-19
2013-07-29
2016-01-19
Article - Refereed
BMC Systems Biology. 2013 Jul 29;7(1):68
http://hdl.handle.net/10919/64469
https://doi.org/10.1186/1752-0509-7-68
en
http://creativecommons.org/licenses/by/4.0/
Lasher et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/188952023-05-18T13:28:49Zcom_10919_8195com_10919_25799com_10919_24227com_10919_5532com_10919_23765col_10919_18629col_10919_24302col_10919_24353
Cell-free protein synthesis energized by slowly-metabolized maltodextrin
Wang, Yiran
Zhang, Y. H. Percival
Biological Systems Engineering
Institute for Critical Technology and Applied Science
Background
Cell-free protein synthesis (CFPS) is a rapid and high throughput technology for obtaining proteins from their genes. The primary energy source ATP is regenerated from the secondary energy source through substrate phosphorylation in CFPS.
Results
Distinct from common secondary energy sources (e.g., phosphoenolpyruvate - PEP, glucose-6-phosphate), maltodextrin was used for energizing CFPS through substrate phosphorylation and the glycolytic pathway because (i) maltodextrin can be slowly catabolized by maltodextrin phosphorylase for continuous ATP regeneration, (ii) maltodextrin phosphorylation can recycle one phosphate per reaction for glucose-1-phosphate generation, and (iii) the maltodextrin chain-shortening reaction can produce one ATP per glucose equivalent more than glucose can. Three model proteins, esterase 2 from Alicyclobacillus acidocaldarius, green fluorescent protein, and xylose reductase from Neurospora crassa were synthesized for demonstration.
Conclusion
Slowly-metabolized maltodextrin as a low-cost secondary energy compound for CFPS produced higher levels of proteins than PEP, glucose, and glucose-6-phospahte. The enhancement of protein synthesis was largely attributed to better-controlled phosphate levels (recycling of inorganic phosphate) and a more homeostatic reaction environment.
2012-08-24
2012-08-24
2009-06-28
2012-08-24
Article - Refereed
BMC Biotechnology. 2009 Jun 28;9(1):58
http://hdl.handle.net/10919/18895
https://doi.org/10.1186/1472-6750-9-58
en
http://creativecommons.org/licenses/by/4.0/
Yiran Wang et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/749352023-06-23T15:22:57Zcom_10919_5com_10919_25799com_10919_8195com_10919_23747com_10919_5539com_10919_23765col_10919_70873col_10919_78797col_10919_23748col_10919_24353
Toxicity of Silver Nanoparticles at the Air-Liquid Interface
Holder, Amara L.
Marr, Linsey C.
Civil and Environmental Engineering
Institute for Critical Technology and Applied Science (ICTAS)
Biotechnology & Applied Microbiology
Medicine, Research & Experimental
Research & Experimental Medicine
HUMAN HEPATOMA-CELLS
SPRAGUE-DAWLEY RATS
HUMAN LUNG-CELLS
IN-VITRO
PARTICULATE MATTER
INHALATION TOXICITY
EPITHELIAL-CELLS
EXPOSURE SYSTEM
DIESEL EXHAUST
PARTICLES
Silver nanoparticles are one of the most prevalent nanomaterials in consumer products. Some of these products are likely to be aerosolized, making silver nanoparticles a high priority for inhalation toxicity assessment. To study the inhalation toxicity of silver nanoparticles, we have exposed cultured lung cells to them at the air-liquid interface. Cells were exposed to suspensions of silver or nickel oxide (positive control) nanoparticles at concentrations of 2.6, 6.6, and 13.2 μg cm⁻² (volume concentrations of 10, 25, and 50 μg ml⁻¹) and to 0.7 μg cm⁻² silver or 2.1 μg cm⁻² nickel oxide aerosol at the air-liquid interface. Unlike a number of in vitro studies employing suspensions of silver nanoparticles, which have shown strong toxic effects, both suspensions and aerosolized nanoparticles caused negligible cytotoxicity and only a mild inflammatory response, in agreement with animal exposures. Additionally, we have eveloped a novel method using a differential mobility analyzer to select aerosolized nanoparticles of a single diameter to assess the size-dependent toxicity of silver nanoparticles.
2017-02-05
2017-02-05
2013-01-01
Article - Refereed
Amara L. Holder, Linsey C. Marr, "Toxicity of Silver Nanoparticles at the Air-Liquid Interface", BioMed Research International, vol. 2013, Article ID 328934, 11 pages, 2013. https://doi.org/10.1155/2013/328934
2314-6133
http://hdl.handle.net/10919/74935
https://doi.org/10.1155/2013/328934
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000314416300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Hindawi
oai:vtechworks.lib.vt.edu:10919/474182022-04-08T04:49:39Zcom_10919_23765com_10919_24369com_10919_5539com_10919_23261col_10919_24353col_10919_24370col_10919_23262
Thermal transport in composites of self-assembled nickel nanoparticles embedded in yttria stabilized zirconia
Shukla, Nitin C.
Liao, Hao-Hsiang
Abiade, Jeremiah T.
Murayama, Mitsuhiro
Kumar, Dhananjay
Huxtable, Scott T.
Mechanical Engineering
Institute for Critical Technology and Applied Science (ICTAS)
Materials Science and Engineering (MSE)
Multilayers
Nanoparticles
Nickel
Pulsed laser deposition
Thermal
Conductivity
Yttrium compounds
Zirconium compounds
Conductivity
Nanoscale
Dense
We investigate the effect of nickel nanoparticle size on thermal transport in multilayer nanocomposites consisting of alternating layers of nickel nanoparticles and yttria stabilized zirconia (YSZ) spacer layers that are grown with pulsed laser deposition. Using time-domain thermoreflectance, we measure thermal conductivities of k=1.8, 2.4, 2.3, and 3.0 W m(-1) K(-1) for nanocomposites with nickel nanoparticle diameters of 7, 21, 24, and 38 nm, respectively, and k=2.5 W m(-1) K(-1) for a single 80 nm thick layer of YSZ. We use an effective medium theory to estimate the lower limits for interface thermal conductance G between the nickel nanoparticles and the YSZ matrix (G>170 MW m(-2) K(-1)), and nickel nanoparticle thermal conductivity.
2014-04-16
2014-04-16
2009-04-01
2014-03-27
Article - Refereed
Shukla, Nitin C.; Liao, Hao-Hsiang; Abiade, Jeremiah T.; et al., "Thermal transport in composites of self-assembled nickel nanoparticles embedded in yttria stabilized zirconia," Appl. Phys. Lett. 94, 151913 (2009); http://dx.doi.org/10.1063/1.3116715
0003-6951
http://hdl.handle.net/10919/47418
http://scitation.aip.org/content/aip/journal/apl/94/15/10.1063/1.3116715
https://doi.org/10.1063/1.3116715
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/1141392023-03-22T07:11:53Zcom_10919_23765col_10919_24353
Laboratory evaluation of climbing helmets: assessment of linear acceleration
Begonia, Mark T.
Rowson, Bethany M.
Scicli, Blake
Goff, John Eric
climbing
helmet
head injury
linear acceleration
This study utilized a guided free-fall drop tower and standard test headform to measure the peak linear acceleration (PLA) generated by different climbing helmet models that were impacted at various speeds (2-6 m s(-1)) and locations (top, front, rear, side). Wide-ranging impact performance was observed for the climbing helmet models selected. Helmets that produced lower PLAs were composed of protective materials, such as expanded polystyrene (EPS) or expanded polypropylene, which were integrated throughout multiple helmet regions including the front, rear and side. Climbing helmets that produced the highest PLAs consisted of a chinstrap, a suspension system, an acrylontrile butadiene styrene (ABS) outer shell, and an EPS inner layer, which was applied only to the top location. Variation in impact protection was attributed not only to helmet model but also impact location. Although head acceleration measurements were fairly similar between helmet models at the top location, impacts to the front, rear, and side led to larger changes in PLA. A 300 g cutoff for PLA was chosen due to its use as a pass/fail threshold in other helmet safety standards, and because it represents a high risk of severe head injury. All seven helmet models had the lowest acceleration values at the top location with PLAs below 300 g at speeds as high as 6 m s(-1). Impact performance varied more substantially at the front, rear, and side locations, with some models generating PLAs above 300 g at speeds as low as 3 m s(-1). These differences in impact performance represent opportunities for improved helmet design to better protect climbers across a broader range of impact scenarios in the event of a fall or other collision. An understanding of how current climbing helmets attenuate head acceleration could allow manufacturers to enhance next-generation models with innovative and more robust safety features including smart materials.
2023-03-21
2023-03-21
2023-03-01
Article - Refereed
34003
http://hdl.handle.net/10919/114139
https://doi.org/10.1088/1361-665X/acb6ea
32
3
1361-665X
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
IOP Publishing
oai:vtechworks.lib.vt.edu:10919/1111742022-07-26T13:33:08Zcom_10919_8195com_10919_25799com_10919_23765col_10919_78882col_10919_24353
Transcriptional Interference Regulates the Evolutionary Development of Speech
Mortlock, Douglas P.
Fang, Zhi-Ming
Chandler, Kelly J.
Hou, Yue
Bickford, Lissett R.
de Bock, Charles E.
Eapen, Valsamma
Clarke, Raymond A.
The human capacity to speak is fundamental to our advanced intellectual, technological and social development. Yet so very little is known regarding the evolutionary genetics of speech or its relationship with the broader aspects of evolutionary development in primates. In this study, we describe a large family with evolutionary retrograde development of the larynx and wrist. The family presented with severe speech impairment and incremental retrograde elongations of the pisiform in the wrist that limited wrist rotation from 180° to 90° as in primitive primates. To our surprise, we found that a previously unknown primate-specific gene <i>TOSPEAK</i> had been disrupted in the family. <i>TOSPEAK</i> emerged de novo in an ancestor of extant primates across a 540 kb region of the genome with a pre-existing highly conserved long-range laryngeal enhancer for a neighbouring bone morphogenetic protein gene <i>GDF6</i>. We used transgenic mouse modelling to identify two additional <i>GDF6</i> long-range enhancers within <i>TOSPEAK</i> that regulate <i>GDF6</i> expression in the wrist. Disruption of <i>TOSPEAK</i> in the affected family blocked the transcription of <i>TOSPEAK</i> across the 3 <i>GDF6</i> enhancers in association with a reduction in <i>GDF6</i> expression and retrograde development of the larynx and wrist. Furthermore, we describe how <i>TOSPEAK</i> developed a human-specific promoter through the expansion of a penta-nucleotide direct repeat that first emerged de novo in the promoter of <i>TOSPEAK</i> in gibbon. This repeat subsequently expanded incrementally in higher hominids to form an overlapping series of Sp1/KLF transcription factor consensus binding sites in human that correlated with incremental increases in the promoter strength of <i>TOSPEAK</i> with human having the strongest promoter. Our research indicates a dual evolutionary role for the incremental increases in <i>TOSPEAK</i> transcriptional interference of <i>GDF6</i> enhancers in the incremental evolutionary development of the wrist and larynx in hominids and the human capacity to speak and their retrogression with the reduction of <i>TOSPEAK</i> transcription in the affected family.
2022-07-08
2022-07-08
2022-07-04
2022-07-08
Article - Refereed
Mortlock, D.P.; Fang, Z.-M.; Chandler, K.J.; Hou, Y.; Bickford, L.R.; de Bock, C.E.; Eapen, V.; Clarke, R.A. Transcriptional Interference Regulates the Evolutionary Development of Speech. Genes 2022, 13, 1195.
http://hdl.handle.net/10919/111174
https://doi.org/10.3390/genes13071195
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/1148272023-04-28T07:12:43Zcom_10919_8195com_10919_25799com_10919_24216com_10919_5539com_10919_23765com_10919_84995com_10919_5553col_10919_78882col_10919_24286col_10919_24353col_10919_84996
Atypical Neurogenesis, Astrogliosis, and Excessive Hilar Interneuron Loss Are Associated with the Development of Post-Traumatic Epilepsy
Gudenschwager-Basso, Erwin Kristobal
Shandra, Oleksii
Volanth, Troy
Patel, Dipan C.
Kelly, Colin
Browning, Jack L.
Wei, Xiaoran
Harris, Elizabeth A.
Mahmutovic, Dzenis
Kaloss, Alexandra M.
Correa, Fernanda Guilhaume
Decker, Jeremy
Maharathi, Biswajit
Robel, Stefanie
Sontheimer, Harald
VandeVord, Pamela J.
Olsen, Michelle L.
Theus, Michelle H.
Background: Traumatic brain injury (TBI) remains a significant risk factor for post-traumatic epilepsy (PTE). The pathophysiological mechanisms underlying the injury-induced epileptogenesis are under investigation. The dentate gyrus—a structure that is highly susceptible to injury—has been implicated in the evolution of seizure development. Methods: Utilizing the murine unilateral focal control cortical impact (CCI) injury, we evaluated seizure onset using 24/7 EEG video analysis at 2–4 months post-injury. Cellular changes in the dentate gyrus and hilus of the hippocampus were quantified by unbiased stereology and Imaris image analysis to evaluate Prox1-positive cell migration, astrocyte branching, and morphology, as well as neuronal loss at four months post-injury. Isolation of region-specific astrocytes and RNA-Seq were performed to determine differential gene expression in animals that developed post-traumatic epilepsy (PTE<sup>+</sup>) vs. those animals that did not (PTE<sup>−</sup>), which may be associated with epileptogenesis. Results: CCI injury resulted in 37% PTE incidence, which increased with injury severity and hippocampal damage. Histological assessments uncovered a significant loss of hilar interneurons that coincided with aberrant migration of Prox1-positive granule cells and reduced astroglial branching in PTE<sup>+</sup> compared to PTE<sup>−</sup> mice. We uniquely identified <i>Cst3</i> as a PTE<sup>+</sup>-specific gene signature in astrocytes across all brain regions, which showed increased astroglial expression in the PTE<sup>+</sup> hilus. Conclusions: These findings suggest that epileptogenesis may emerge following TBI due to distinct aberrant cellular remodeling events and key molecular changes in the dentate gyrus of the hippocampus.
2023-04-27
2023-04-27
2023-04-25
2023-04-27
Article - Refereed
Gudenschwager-Basso, E.K.; Shandra, O.; Volanth, T.; Patel, D.C.; Kelly, C.; Browning, J.L.; Wei, X.; Harris, E.A.; Mahmutovic, D.; Kaloss, A.M.; Correa, F.G.; Decker, J.; Maharathi, B.; Robel, S.; Sontheimer, H.; VandeVord, P.J.; Olsen, M.L.; Theus, M.H. Atypical Neurogenesis, Astrogliosis, and Excessive Hilar Interneuron Loss Are Associated with the Development of Post-Traumatic Epilepsy. Cells 2023, 12, 1248.
http://hdl.handle.net/10919/114827
https://doi.org/10.3390/cells12091248
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/1142082023-03-29T07:12:40Zcom_10919_8195com_10919_25799com_10919_23765col_10919_78882col_10919_24353
Determination of Hydrophobic Dispersive Surface Free Energy of Activated Carbon Fibers Measured by Inverse Gas Chromatographic Technique
Lee, Seul-Yi
Kim, Yeong-Hun
Mahajan, Roop L.
Park, Soo-Jin
Activated carbon fibers (ACFs) as one of the most important porous carbon materials are widely used in many applications that involve rapid adsorption and low-pressure loss, including air purification, water treatment, and electrochemical applications. For designing such fibers for the adsorption bed in gas and aqueous phases, in-depth comprehension of the surface components is crucial. However, achieving reliable values remains a major challenge due to the high adsorption affinity of ACFs. To overcome this problem, we propose a novel approach to determine London dispersive components (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>γ</mi><mi>S</mi><mi>L</mi></msubsup></mrow></semantics></math></inline-formula>) of the surface free energy of ACFs by inverse gas chromatography (IGC) technique at an infinite dilution. Our data reveal the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>γ</mi><mi>S</mi><mi>L</mi></msubsup></mrow></semantics></math></inline-formula> values at 298 K for bare carbon fibers (CFs) and the ACFs to be 97 and 260–285 mJ·m<sup>−2</sup>, respectively, which lie in the regime of secondary bonding of physical adsorption. Our analysis indicates that these are impacted by micropores and defects on the carbon surfaces. Comparing the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mi>γ</mi><mi>S</mi><mi>L</mi></msubsup></mrow></semantics></math></inline-formula> obtained by the traditional Gray’s method, our method is concluded as the most accurate and reliable value for the hydrophobic dispersive surface component of porous carbonaceous materials. As such, it could serve as a valuable tool in designing interface engineering in adsorption-related applications.
2023-03-28
2023-03-28
2023-03-20
2023-03-28
Article - Refereed
Lee, S.-Y.; Kim, Y.-H.; Mahajan, R.L.; Park, S.-J. Determination of Hydrophobic Dispersive Surface Free Energy of Activated Carbon Fibers Measured by Inverse Gas Chromatographic Technique. Nanomaterials 2023, 13, 1113.
http://hdl.handle.net/10919/114208
https://doi.org/10.3390/nano13061113
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/865882022-11-01T17:33:50Zcom_10919_112356com_10919_23261com_10919_5539com_10919_23765col_10919_112358col_10919_24353
Compositionally Graded Multilayer Ceramic Capacitors
Song, Hyun-Cheol
Zhou, Jie E.
Maurya, Deepam
Yan, Yongke
Wang, Yu U.
Priya, Shashank
effective pyroelectric coefficients
ferroelectric domain formation
high-temperature
computer-simulation
0.9batio(3)-0.1(bi0.5na0.5)tio3 ceramics
dielectric-properties
behavior
field
batio3
films
Multilayer ceramic capacitors (MLCC) are widely used in consumer electronics. Here, we provide a transformative method for achieving high dielectric response and tunability over a wide temperature range through design of compositionally graded multilayer (CGML) architecture. Compositionally graded MLCCs were found to exhibit enhanced dielectric tunability (70%) along with small dielectric losses (< 2.5%) over the required temperature ranges specified in the standard industrial classifications. The compositional grading resulted in generation of internal bias field which enhanced the tunability due to increased nonlinearity. The electric field tunability of MLCCs provides an important avenue for design of miniature filters and power converters.
2019-01-03
2019-01-03
2017-09-27
Article - Refereed
2045-2322
12353
http://hdl.handle.net/10919/86588
https://doi.org/10.1038/s41598-017-12402-7
7
28955052
en_US
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Springer Nature
oai:vtechworks.lib.vt.edu:10919/186342023-12-11T11:08:48Zcom_10919_8195com_10919_25799com_10919_19035com_10919_5539com_10919_25796com_10919_23765col_10919_18629col_10919_24290col_10919_25797col_10919_24353
Sensitive Detection of Pathway Perturbations in Cancers
Rivera, Corban G.
Tyler, Brett M.
Murali, T. M.
Computer Science
Fralin Life Sciences Institute
Institute for Critical Technology and Applied Science (ICTAS)
Background
The normal functioning of a living cell is characterized by complex interaction networks involving many different types of molecules. Associations detected between diseases and perturbations in well-defined pathways within such interaction networks have the potential to illuminate the molecular mechanisms underlying disease progression and response to treatment.
Results
In this paper, we present a computational method that compares expression profiles of genes in cancer samples to samples from normal tissues in order to detect perturbations of pre-defined pathways in the cancer. In contrast to many previous methods, our scoring function approach explicitly takes into account the interactions between the gene products in a pathway. Moreover, we compute the sub-pathway that has the highest score, as opposed to merely computing the score for the entire pathway. We use a permutation test to assess the statistical significance of the most perturbed sub-pathway. We apply our method to 20 pathways in the Netpath database and to the Global Cancer Map of gene expression in 18 cancers. We demonstrate that our method yields more sensitive results than alternatives that do not consider interactions or measure the perturbation of a pathway as a whole. We perform a sensitivity analysis to show that our approach is robust to modest changes in the input data. Our method confirms numerous well-known connections between pathways and cancers.
Conclusions
Our results indicate that integrating differential gene expression with the interaction structure in a pathway is a powerful approach for detecting links between a cancer and the pathways perturbed in it. Our results also suggest that even well-studied pathways may be perturbed only partially in any given cancer. Further analysis of cancer-specific sub-pathways may shed new light on the similarities and differences between cancers.
2012-03-21
2012-03-21
2012-03-21
2012-03-21
Article - Refereed
BMC Bioinformatics. 2012 Mar 21;13(Suppl 3):S9
http://hdl.handle.net/10919/18634
https://doi.org/10.1186/1471-2105-13-S3-S9
en
ACM Conference on Bioinformatics, Computational Biology and Biomedicine 2011 (ACM-BCB) Chicago, IL, USA. 1-3 August 2011
http://creativecommons.org/licenses/by/4.0/
et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1112142022-12-20T13:11:05Zcom_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_23765com_10919_23261col_10919_24286col_10919_24342col_10919_24353col_10919_23262
Exploration of Novel Pathways Underlying Irreversible Electroporation Induced Anti-Tumor Immunity in Pancreatic Cancer
Imran, Khan Mohammad
Nagai-Singer, Margaret A.
Brock, Rebecca M.
Alinezhadbalalami, Nastaran
Davalos, Rafael V.
Allen, Irving C.
pancreatic cancer
irreversible electroporation
anti-tumor immunity
immunomodulatory pathways
IFN gamma-PD-L1 axis
Advancements in medical sciences and technologies have significantly improved the survival of many cancers; however, pancreatic cancer remains a deadly diagnosis. This malignancy is often diagnosed late in the disease when metastases have already occurred. Additionally, the location of the pancreas near vital organs limits surgical candidacy, the tumor's immunosuppressive environment limits immunotherapy success, and it is highly resistant to radiation and chemotherapy. Hence, clinicians and patients alike need a treatment paradigm that reduces primary tumor burden, activates systemic anti-tumor immunity, and reverses the local immunosuppressive microenvironment to eventually clear distant metastases. Irreversible electroporation (IRE), a novel non-thermal tumor ablation technique, applies high-voltage ultra-short pulses to permeabilize targeted cell membranes and induce cell death. Progression with IRE technology and an array of research studies have shown that beyond tumor debulking, IRE can induce anti-tumor immune responses possibly through tumor neo-antigen release. However, the success of IRE treatment (i.e. full ablation and tumor recurrence) is variable. We believe that IRE treatment induces IFN gamma expression, which then modulates immune checkpoint molecules and thus leads to tumor recurrence. This indicates a co-therapeutic use of IRE and immune checkpoint inhibitors as a promising treatment for pancreatic cancer patients. Here, we review the well-defined and speculated pathways involved in the immunostimulatory effects of IRE treatment for pancreatic cancer, as well as the regulatory pathways that may negate these anti-tumor responses. By defining these underlying mechanisms, future studies may identify improvements to systemic immune system engagement following local tumor ablation with IRE and beyond.
2022-07-12
2022-07-12
2022-03-18
Article - Refereed
2234-943X
853779
http://hdl.handle.net/10919/111214
https://doi.org/10.3389/fonc.2022.853779
12
35372046
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Frontiers
oai:vtechworks.lib.vt.edu:10919/766152023-04-18T18:48:42Zcom_10919_5com_10919_25799com_10919_23765col_10919_70873col_10919_24353
Building a safety program to protect the nanotechnology workforce: a guide for small to medium-sized enterprises.
Hull, Matthew S.
U.S. Department of Health and Human Services, Centers for Disease Control and Prevention
This guide provides entrepreneurs and business owners with the tools necessary to develop and implement a written health and safety program to protect employees and colleagues. The guide helps readers recognize and control potential hazards and risks from nanomaterial processes that may adversely impact the health, safety, and well-being of employees and the productivity of business.
2017-03-11
2017-03-11
2016-03-31
Report
http://hdl.handle.net/10919/76615
Hull, MS [0000-0002-5771-8481]
Building a safety program to protect the nanotechnology workforce: a guide for small to medium-sized enterprises.
https://www.cdc.gov/niosh/docs/2016-102/pdfs/2016-102.pdf
http://creativecommons.org/publicdomain/zero/1.0/
Creative Commons CC0 1.0 Universal Public Domain Dedication
National Institute For Occupational Safety And Health, Dhhs (NIOSH)
oai:vtechworks.lib.vt.edu:10919/877172023-05-18T13:28:55Zcom_10919_24227com_10919_5532com_10919_23765col_10919_24302col_10919_24353
A high-energy-density sugar biobattery based on a synthetic enzymatic pathway
Zhu, Zhiguang
Tam, Tsz Kin
Sun, Fangfang
You, Chun
Zhang, Y. H. Percival
Biological Systems Engineering
Institute for Critical Technology and Applied Science
High-energy-density, green, safe batteries are highly desirable for meeting the rapidly growing needs of portable electronics. The incomplete oxidation of sugars mediated by one or a few enzymes in enzymatic fuel cells suffers from low energy densities and slow reaction rates. Here we show that nearly 24 electrons per glucose unit of maltodextrin can be produced through a synthetic catabolic pathway that comprises 13 enzymes in an air-breathing enzymatic fuel cell. This enzymatic fuel cell is based on non-immobilized enzymes that exhibit a maximum power output of 0.8 mW cm(-2) and a maximum current density of 6 mA cm(-2), which are far higher than the values for systems based on immobilized enzymes. Enzymatic fuel cells containing a 15% (wt/v) maltodextrin solution have an energy-storage density of 596 Ah kg(-1), which is one order of magnitude higher than that of lithium-ion batteries. Sugar-powered biobatteries could serve as next-generation green power sources, particularly for portable electronics.
2019-02-19
2019-02-19
2014-01
Article - Refereed
2041-1723
3026
http://hdl.handle.net/10919/87717
https://doi.org/10.1038/ncomms4026
5
24445859
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Springer Nature
oai:vtechworks.lib.vt.edu:10919/1007772020-11-24T17:46:06Zcom_10919_19035com_10919_5539com_10919_23765col_10919_24290col_10919_24353
Automating the PathLinker app for Cytoscape
Huang, Li Jun
Law, Jeffrey N.
Murali, T. M.
Network Biology
Shortest Paths
Pathway Reconstruction
CyREST API
PathLinker is a graph-theoretic algorithm originally developed to reconstruct the interactions in a signaling pathway of interest. It efficiently computes multiple short paths within a background protein interaction network from the receptors to transcription factors (TFs) in a pathway. Since December 2015, PathLinker has been available as an app for Cytoscape. This paper describes how we automated the app to use the CyRest infrastructure and how users can incorporate PathLinker into their software pipelines.
2020-11-03
2020-11-03
2018-06-12
Article - Refereed
Huang LJ, Law JN and Murali TM. Automating the PathLinker app for Cytoscape [version 1; peer review: 2 approved] F1000Research 2018, 7:727 https://doi.org/10.12688/f1000research.14616.1
http://hdl.handle.net/10919/100777
https://doi.org/10.12688/f1000research.14616.1
7
727
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
F1000Research
oai:vtechworks.lib.vt.edu:10919/1069052021-12-10T08:33:11Zcom_10919_8195com_10919_25799com_10919_23765col_10919_78882col_10919_24353
Detectability of the Critically Endangered Araucaria angustifolia Tree Using Worldview-2 Images, Google Earth Engine and UAV-LiDAR
Saad, Felipe
Biswas, Sumalika
Huang, Qiongyu
Corte, Ana Paula Dalla
Coraiola, Márcio
Macey, Sarah
Carlucci, Marcos Bergmann
Leimgruber, Peter
The Brazilian Atlantic Forest is a global biodiversity hotspot and has been extensively mapped using satellite remote sensing. However, past mapping focused on overall forest cover without consideration of keystone plant resources such as <i>Araucaria angustifolia.</i> <i>A. angustifolia</i> is a critically endangered coniferous tree that is essential for supporting overall biodiversity in the Atlantic Forest. <i>A. angustifolia’s</i> distribution has declined dramatically because of overexploitation and land-use changes. Accurate detection and rapid assessments of the distribution and abundance of this species are urgently needed. We compared two approaches for mapping <i>Araucaria angustifolia</i> across two scales (stand vs. individual tree) at three study sites in Brazil. The first approach used Worldview-2 images and Random Forest in Google Earth Engine to detect <i>A. angustifolia</i> at the stand level, with an accuracy of >90% across all three study sites. The second approach relied on object identification using UAV-LiDAR and successfully mapped individual trees (producer’s/user’s accuracy = 94%/64%) at one study site. Both approaches can be employed in tandem to map remaining stands and to determine the exact location of <i>A. angustifolia</i> trees. Each approach has its own strengths and weaknesses, and we discuss their adoptability by managers to inform conservation of <i>A. angustifolia</i>.
2021-12-09
2021-12-09
2021-11-30
2021-12-09
Article - Refereed
Saad, F.; Biswas, S.; Huang, Q.; Corte, A.P.D.; Coraiola, M.; Macey, S.; Carlucci, M.B.; Leimgruber, P. Detectability of the Critically Endangered Araucaria angustifolia Tree Using Worldview-2 Images, Google Earth Engine and UAV-LiDAR. Land 2021, 10, 1316.
http://hdl.handle.net/10919/106905
https://doi.org/10.3390/land10121316
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Brazil
MDPI
oai:vtechworks.lib.vt.edu:10919/775532022-02-26T16:07:07Zcom_10919_23765com_10919_79468com_10919_78628col_10919_24353col_10919_79481
Waste not want not: life cycle implications of gold recovery and recycling from nanowaste
Pati, Paramjeet
McGinnis, Sean
Vikesland, Peter J.
Institute for Critical Technology and Applied Science
Materials Science and Engineering
Civil and Environmental Engineering
Commercial-scale applications of nanotechnology are rapidly increasing. Enhanced production of nanomaterials and nano-enabled products and their resultant disposal lead to concomitant increases in the volume of nanomaterial wastes (i.e., nanowaste). Many nanotechnologies employ resource-limited materials, such as precious metals and rare earth elements that ultimately end up as nanowaste. To make nanotechnology more sustainable it is essential to develop strategies to recover these high-value, resource-limited materials. To address this complex issue, we developed laboratory-scale methods to recover nanowaste gold. To this end, α-cyclodextrin facilitated host–guest inclusion complex formation involving second-sphere coordination of [AuBr4]− and [K(OH2)6]+ was used for gold recovery and the recovered gold was then used to produce new nanoparticles. To quantify the environmental impacts of this gold recycling process we then produced life cycle assessments to compare nanoparticulate gold production scenarios with and without recycling. The LCA results indicate that recovery and recycling of nanowaste gold can significantly reduce the environmental impacts of gold nanoparticle synthesis.
2017-05-01
2017-05-01
2016-08-24
Article - Refereed
2051-8153
http://hdl.handle.net/10919/77553
https://doi.org/10.1039/c6en00181e
3
5
2051-8161
en_US
Royal Society of Chemistry Gold Open Access - 2016
http://creativecommons.org/licenses/by-nc/3.0/
Pati, Paramjeet
McGinnis, Sean
Vikesland, Peter J.
Creative Commons Attribution-NonCommercial 3.0 Unported
Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/649602023-11-29T11:07:35Zcom_10919_23842com_10919_5553com_10919_23765com_10919_51731com_10919_5478col_10919_23843col_10919_24353col_10919_51732
Size dependent ion-exchange of large mixed-metal complexes into Nafion® membranes
Naughton, Elise M.
Zhang, Mingqiang
Troya, Diego
Brewer, Karen J.
Moore, Robert Bowen
Chemistry
Macromolecules Innovation Institute
Institute for Critical Technology and Applied Science
Perfluorosulfonate ionomers have been shown to demonstrate a profound affinity for large cationic complexes, and the exchange of these ions may be used to provide insight regarding Nafion® morphology by contrasting molecular size with existing morphological models. The trimetallic complex, [{(bpy)2Ru(dpp)}2RhBr2]5+, is readily absorbed by ion-exchange into Na+-form Nafion® membranes under ambient conditions. The dimensions of three different isomers of the trimetallic complex were found to be: 23.6 Å × 13.3 Å × 10.8 Å, 18.9 Å × 18.0 Å × 13.7 Å, and 23.1 Å × 12.0 Å × 11.4 Å, yielding an average molecular volume of 1.2 × 103 Å3. At equilibrium, the partition coefficient for the ion-exchange of the trimetallic complex into Nafion® from a DMF solution was found to be 5.7 × 103. Furthermore, the total cationic charge of the exchanged trimetallic complexes was found to counterbalance 86 ± 2% of the anionic SO3− sites in Nafion®. The characteristic dimensions of morphological models for the ionic domains in Nafion® were found to be comparable to the molecular dimensions of the large mixed-metal complexes. Surprisingly, SAXS analysis indicated that the complexes absorbed into the ionic domains of Nafion® without significantly changing the ionomer morphology. Given the profound affinity for absorption of these large cationic molecules, a more open-channel model for the morphology of perfluorosulfonate ionomers is more reasonable, in agreement with recent experimental findings. In contrast to smaller monometallic complexes, the time dependent uptake of the large trimetallic cations was found to be biexponential. This behavior is attributed to a fast initial ion-exchange process on the surface of the membrane, accompanied by a slower transport-limited ion-exchange for exchange sites that are buried further in the ionomer matrix.
2016-03-18
2016-03-18
2015-08-18
2016-03-17
Article - Refereed
Naughton, E. M., Zhang, M., Troya, D., Brewer, K. J., & Moore, R. B. (2015). Size dependent ion-exchange of large mixed-metal complexes into Nafion® membranes. Polymer Chemistry, 6(38), 6870-6879. doi:10.1039/C5PY00714C
1759-9954
2015_Naughton_Size_dependent_ion_exchange.pdf
DE FG02-05-ER15751
DMR-0923107
http://hdl.handle.net/10919/64960
https://doi.org/10.1039/C5PY00714C
6
38
en_US
http://creativecommons.org/licenses/by-nc/3.0/
Creative Commons Attribution-NonCommercial 3.0 Unported
The Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/943222023-12-12T14:54:58Zcom_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_18738com_10919_91913com_10919_23198com_10919_23765com_10919_24263com_10919_91912col_10919_24286col_10919_24342col_10919_23145col_10919_91914col_10919_24353col_10919_24345col_10919_91916
High-frequency irreversible electroporation is an effective tumor ablation strategy that induces immunologic cell death and promotes systemic anti-tumor immunity
Ringel-Scaia, Veronica M.
Beitel-White, Natalie
Lorenzo, Melvin F.
Brock, Rebecca M.
Huie, Kathleen E.
Coutermarsh-Ott, Sheryl
Eden, Kristin
McDaniel, Dylan K.
Verbridge, Scott S.
Rossmeisl, John H. Jr.
Oestreich, Kenneth J.
Davalos, Rafael V.
Allen, Irving C.
Electrical and Computer Engineering
Biomedical Engineering and Mechanics
Biomedical Sciences and Pathobiology
Small Animal Clinical Sciences
Fralin Biomedical Research Institute
Institute for Critical Technology and Applied Sciences
Virginia Tech Carilion School of Medicine
IRE
Breast cancer
Metastasis
Tumor microenvironment
Pyroptosis
Background: Despite promising treatments for breast cancer, mortality rates remain high and treatments for metastatic disease are limited. High-frequency irreversible electroporation (H-FIRE) is a novel tumor ablation technique that utilizes high-frequency bipolar electric pulses to destabilize cancer cell membranes and induce cell death. However, there is currently a paucity of data pertaining to immune system activation following H-FIRE and other electroporation based tumor ablation techniques. Methods: Here, we utilized the mouse 4T1 mammary tumor model to evaluate H-FIRE treatment parameters on cancer progression and immune system activation in vitro and in vivo. Findings: H-FIRE effectively ablates the primary tumor and induces a pro-inflammatory shift in the tumor microenvironment. We further show that local treatment with H-FIRE significantly reduces 4T1 metastases. H-FIRE kills 4T1 cells through non-thermal mechanisms associated with necrosis and pyroptosis resulting in damage associated molecular pattern signaling in vitro and in vivo. Our data indicate that the level of tumor ablation correlates with increased activation of cellular immunity. Likewise, we show that the decrease in metastatic lesions is dependent on the intact immune system and H-FIRE generates 4T1 neoantigens that engage the adaptive immune system to significantly attenuate tumor progression. Interpretation: Cell death and tumor ablation following H-FIRE treatment activates the local innate immune system, which shifts the tumor microenvironment from an anti-inflammatory state to a pro-inflammatory state. The non-thermal damage to the cancer cells and increased innate immune system stimulation improves antigen presentation, resulting in the engagement of the adaptive immune system and improved systemic anti-tumor immunity. (C) 2019 The Authors. Published by Elsevier B.V.
2019-10-02
2019-10-02
2019-06
Article - Refereed
2352-3964
http://hdl.handle.net/10919/94322
https://doi.org/10.1016/j.ebiom.2019.05.036
44
31130474
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
oai:vtechworks.lib.vt.edu:10919/775592023-06-23T15:22:48Zcom_10919_23842com_10919_5553com_10919_23747com_10919_5539com_10919_23765col_10919_23843col_10919_23748col_10919_24353
Protein-aided formation of triangular silver nanoprisms with enhanced SERS performance
Geng, Xi
Leng, Weinan
Carter, Nathan A.
Vikesland, Peter J.
Grove, Tijana Z.
Chemistry
Civil and Environmental Engineering
Institute for Critical Technology and Applied Science
Duke University. Center for the Environmental Implications of Nanotechnology (CEINT)
In this work, we present a modified seed-mediated synthetic strategy for the growth of silver nanoprisms with low shape polydispersity, narrow size distribution and tailored plasmonic absorbance. During the seed nucleation step, consensus sequence tetratricopeptide repeat (CTPR) proteins are utilized as potent stabilizers to facilitate the formation of planar-twinned Ag seeds. Ag nanoprisms were produced in high yield in a growth solution containing ascorbic acid and CTPR-stabilized Ag seeds. From the time-course UV-Vis and transmission electron microscopy (TEM) studies, we postulate that the growth mechanism is the combination of facet selective lateral growth and thermodynamically driven Ostwald ripening. The resultant Ag nanotriangles (NTs) exhibit excellent surface enhanced Raman spectroscopy (SERS) performance. The enhancement factor (EF) measured for the 4-mercapto benzoic acid (4-MBA) reporter is estimated to be 3.37 × 105 in solution and 2.8 × 106 for the SERS substrate.
2017-05-01
2017-05-01
2016-05-10
Article - Refereed
2050-750X
http://hdl.handle.net/10919/77559
https://doi.org/10.1039/c6tb00844e
4
23
2050-7518
en
Royal Society of Chemistry Gold Open Access - 2016
http://creativecommons.org/licenses/by-nc/3.0/
Geng, Xi
Leng, Weinan
Carter, Nathan A.
Vikesland, Peter J.
Grove, Tijana Z.
Creative Commons Attribution-NonCommercial 3.0 Unported
Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/259082020-10-15T17:45:21Zcom_10919_23765com_10919_23261com_10919_5539col_10919_24353col_10919_23262
Foam-based optical absorber for high-power laser radiometry
Ramadurai, Krishna
Cromer, Christopher L.
Li, Xiaoyu
Mahajan, Roop L.
Lehman, John H.
Mechanical Engineering
Institute for Critical Technology and Applied Science (ICTAS)
Forced-convection
Metal foams
Calorimeter
We report damage threshold measurements of novel absorbers comprised of either liquid-cooled silicon carbide or vitreous carbon foams. The measurements demonstrate damage thresholds up to 1.6 x 104 W/cm(2) at an incident circular spot size of 2 mm with an absorbance of 96% at 1.064 mu m. We present a summary of the damage threshold as a function of the water flow velocity and the absorbance measurements. We also present a qualitative description of a damage mechanism based on a two-phase heat transfer between the foam and the flowing water. (c) 2007 Optical Society of America.
2014-03-14
2014-03-14
2007-12-01
2014-02-06
Article - Refereed
Krishna Ramadurai, Christopher L. Cromer, Xiaoyu Li, Roop L. Mahajan, and John H. Lehman, "Foam-based optical absorber for high-power laser radiometry," Appl. Opt. 46, 8268-8271 (2007); doi: 10.1364/ao.46.008268
1559-128X
http://hdl.handle.net/10919/25908
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-46-34-8268
https://doi.org/10.1364/ao.46.008268
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
Optical Society of America
oai:vtechworks.lib.vt.edu:10919/816012024-03-12T15:58:38Zcom_10919_5com_10919_25799com_10919_8195com_10919_24226com_10919_5532com_10919_24214com_10919_5539com_10919_23765col_10919_70873col_10919_18629col_10919_24301col_10919_24288col_10919_24353
The hepatocyte proteome in organotypic rat liver models and the influence of the local microenvironment
Vu, Lucas T.
Orbach, Sophia M.
Ray, W. Keith
Cassin, Margaret E.
Rajagopalan, Padmavathy
Helm, Richard F.
Biochemistry
Chemical Engineering
Institute for Critical Technology and Applied Science
Biochemical Research Methods
Biochemistry & Molecular Biology
Hepatocyte
Ketogenesis
Liver
Polyelectrolyte multilayer
Proteomics
CELL-CELL INTERACTIONS
FARNESOID-X-RECEPTOR
IN-VITRO
GLUCOSE-METABOLISM
NONPARENCHYMAL CELLS
SYSTEMS BIOLOGY
MONOLAYER-CULTURES
COLLAGEN SANDWICH
DRUG-METABOLISM
CANCER CELLS
Background: Liver models that closely mimic the in vivo microenvironment are useful for understanding liver functions, capabilities, and intercellular communication processes. Three-dimensional (3D) liver models assembled using hepatocytes and liver sinusoidal endothelial cells (LSECs) separated by a polyelectrolyte multilayer (PEM) provide a functional system while also permitting isolation of individual cell types for proteomic analyses.
Methods: To better understand the mechanisms and processes that underlie liver model function, hepatocytes were maintained as monolayers and 3D PEM-based formats in the presence or absence of primary LSECs. The resulting hepatocyte proteomes, the proteins in the PEM, and extracellular levels of urea, albumin and glucose after three days of culture were compared.
Results: All systems were ketogenic and found to release glucose. The presence of the PEM led to increases in proteins associated with both mitochondrial and peroxisomal-based β-oxidation. The PEMs also limited production of structural and migratory proteins associated with dedifferentiation. The presence of LSECs increased levels of Phase I and Phase II biotransformation enzymes as well as several proteins associated with the endoplasmic reticulum and extracellular matrix remodeling. The proteomic analysis of the PEMs indicated that there was no significant change after three days of culture. These results are discussed in relation to liver model function.
Conclusions: Heterotypic cell-cell and cell-ECM interactions exert different effects on hepatocyte functions and phenotypes.
2018-01-08
2018-01-08
2017-06-20
Article - Refereed
Proteome Science. 2017 Jun 20;15(1):12
1477-5956
http://hdl.handle.net/10919/81601
https://doi.org/10.1186/s12953-017-0120-6
15
Helm, RF [0000-0001-5317-0925]
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000405227100001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Biomed Central
oai:vtechworks.lib.vt.edu:10919/1087852023-11-29T11:21:50Zcom_10919_5com_10919_25799com_10919_23747com_10919_5539com_10919_111734com_10919_25796com_10919_23765com_10919_24369col_10919_70873col_10919_23748col_10919_111736col_10919_24353col_10919_24370
Life Cycle Impact Assessment of Iron Oxide (Fe3O4/γ-Fe2O3) Nanoparticle Synthesis Routes
Rahman, Asifur
Kang, Seju
McGinnis, Sean
Vikesland, Peter J.
The synthesis of superparamagnetic iron oxide nanoparticles (FeOx-NPs) has rapidly developed over the past decade due to their wide-ranging applications in research and technology. However, at present there exists very limited knowledge about the environmental impacts of the various input materials and the energy required for different FeOx-NP synthesis approaches. In this study, we used cradle-to-gate life cycle assessment (LCA) to analyze and compare the environmental impacts of FeOx-NPs produced via seven common synthesis routes. Four different functional units (i.e., mass, mean particle size, specific surface area, and saturation magnetization) were used to normalize the environmental impacts and evaluate the corresponding changes. Overall, physical and biological synthesis routes exhibited high environmental impacts due to their higher input material and energy requirements. Interestingly, biological syntheses had the highest environmental impacts due to their reliance on bacterial culture media. All of the chemical synthesis routes had lower environmental impacts except the thermal decomposition method, which had higher environmental impacts due its use of non-polar organic solvents during synthesis. The lab-scale LCA inventory data and analysis presented here addresses the existing data gaps and helps guide future research for FeOx-NP synthesis under industrial conditions. The information generated by this effort aids in the identification of environmentally friendly and sustainable production pathways for FeOx-NPs.
2022-02-21
2022-02-21
2022
2022-02-21
Article - Refereed
http://hdl.handle.net/10919/108785
McGinnis, Sean [0000-0001-8931-9429]
Vikesland, Peter [0000-0003-2654-5132]
en
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
oai:vtechworks.lib.vt.edu:10919/967612022-02-25T02:49:18Zcom_10919_24214com_10919_5539com_10919_23765com_10919_23274col_10919_24288col_10919_24353col_10919_23275
The assembly of integrated rat intestinal-hepatocyte cultures
Kothari, Anjaney
Rajagopalan, Padmavathy
Chemical Engineering
Institute for Critical Technology and Applied Science (ICTAS)
School of Biomedical Engineering and Sciences
integrated cultures
liver
small intestine
The jejunum is the segment of the small intestine responsible for several metabolism and biotransformation functions. In this report, we have cultured rat jejunum explants in vitro and integrated them with hepatocyte cultures. We have also investigated the changes in jejunum function at different locations since spatial variations in intestinal functions have been reported previously. We divided the length of the rat jejunum into three distinct regions of approximately 9 cm each. We defined the regions as proximal (adjacent to the duodenum), medial, and distal (adjacent to the ileum). Spatiotemporal variations in functions were observed between these regions within the jejunum. Alkaline phosphatase activity (a marker of enterocyte function), decreased twofold between the proximal and distal regions at 4 hr. Lysozyme activity (a marker of Paneth cell function) increased from the proximal to the distal jejunum by 40% at 24 hr. Mucin-covered areas, a marker of goblet cell function, increased by twofold between the proximal and distal segments of the jejunum at 24 hr. When hepatocytes were integrated with proximal jejunum explants, statistically higher urea (similar to 2.4-fold) and mucin (57%) production were observed in the jejunum explants. The integrated intestine-liver cultures can be used as a platform for future investigations.
2020-02-07
2020-02-07
2019-11
Article - Refereed
UNSP e10146
http://hdl.handle.net/10919/96761
https://doi.org/10.1002/btm2.10146
2380-6761
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1046402023-06-14T17:50:23Zcom_10919_5com_10919_25799com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_18738com_10919_23765com_10919_24261com_10919_23261com_10919_111086com_10919_5532com_10919_24263com_10919_91912com_10919_23198col_10919_70873col_10919_24286col_10919_24342col_10919_23145col_10919_24353col_10919_24343col_10919_23262col_10919_111087col_10919_24345col_10919_91916
Establishing an immunocompromised porcine model of human cancer for novel therapy development with pancreatic adenocarcinoma and irreversible electroporation
Hendricks-Wenger, Alissa
Aycock, Kenneth N.
Nagai-Singer, Margaret A.
Coutermarsh-Ott, Sheryl
Lorenzo, Melvin F.
Gannon, Jessica
Uh, Kyungjun
Farrell, Kayla
Beitel-White, Natalie
Brock, Rebecca M.
Simon, Alexander
Morrison, Holly A.
Tuohy, Joanne L.
Clark-Deener, Sherrie
Vlaisavljevich, Eli
Davalos, Rafael V.
Lee, Kiho
Allen, Irving C.
Biomedical Engineering and Mechanics
Virginia Tech Carilion School of Medicine
Large Animal Clinical Sciences
Small Animal Clinical Sciences
Mechanical Engineering
Animal and Poultry Sciences
Electrical and Computer Engineering
Biomedical Sciences and Pathobiology
Institute for Critical Technology and Applied Science
tumor xenografts
ablation
mouse
gemcitabine
safety
mice
pigs
immunodeficiency
chemotherapy
feasibility
New therapies to treat pancreatic cancer are direly needed. However, efficacious interventions lack a strong preclinical model that can recapitulate patients’ anatomy and physiology. Likewise, the availability of human primary malignant tissue for ex vivo studies is limited. These are significant limitations in the biomedical device field. We have developed RAG2/IL2RG deficient pigs using CRISPR/Cas9 as a large animal model with the novel application of cancer xenograft studies of human pancreatic adenocarcinoma. In this proof-of-concept study, these pigs were successfully generated using on-demand genetic modifications in embryos, circumventing the need for breeding and husbandry. Human Panc01 cells injected subcutaneously into the ears of RAG2/IL2RG deficient pigs demonstrated 100% engraftment with growth rates similar to those typically observed in mouse models. Histopathology revealed no immune cell infiltration and tumor morphology was highly consistent with the mouse models. The electrical properties and response to irreversible electroporation of the tumor tissue were found to be similar to excised human pancreatic cancer tumors. The ample tumor tissue produced enabled improved accuracy and modeling of the electrical properties of tumor tissue. Together, this suggests that this model will be useful and capable of bridging the gap of translating therapies from the bench to clinical application.
2021-08-13
2021-08-13
2021-04-07
2021-08-13
Article - Refereed
2045-2322
10.1038/s41598-021-87228-5 (PII)
http://hdl.handle.net/10919/104640
https://doi.org/10.1038/s41598-021-87228-5
11
1
Davalos, Rafael [0000-0003-1503-9509]
Clark-Deener, Sherrie [0000-0002-6620-0625]
Allen, Irving [0000-0001-9573-5250]
33828203 (pubmed)
2045-2322
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000640391700021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Nature Research
oai:vtechworks.lib.vt.edu:10919/850742022-02-26T16:07:07Zcom_10919_8195com_10919_25799com_10919_112356com_10919_23261com_10919_5539com_10919_23765com_10919_79468com_10919_78628col_10919_78882col_10919_112358col_10919_24353col_10919_23262col_10919_79481
Combinatory Finite Element and Artificial Neural Network Model for Predicting Performance of Thermoelectric Generator
Kishore, Ravi Anant
Mahajan, Roop L.
Priya, Shashank
Center for Energy Harvesting Materials and Systems (CEHMS)
Mechanical Engineering
Institute for Critical Technology and Applied Science
thermoelectric
bismuth telluride
TEG
neural network
ANN
Thermoelectric generators (TEGs) are rapidly becoming the mainstream technology for converting thermal energy into electrical energy. The rise in the continuous deployment of TEGs is related to advancements in materials, figure of merit, and methods for module manufacturing. However, rapid optimization techniques for TEGs have not kept pace with these advancements, which presents a challenge regarding tailoring the device architecture for varying operating conditions. Here, we address this challenge by providing artificial neural network (ANN) models that can predict TEG performance on demand. Out of the several ANN models considered for TEGs, the most efficient one consists of two hidden layers with six neurons in each layer. The model predicted TEG power with an accuracy of ±0.1 W, and TEG efficiency with an accuracy of ±0.2%. The trained ANN model required only 26.4 ms per data point for predicting TEG performance against the 6.0 minutes needed for the traditional numerical simulations.
2018-09-21
2018-09-21
2018-08-24
2018-09-21
Article - Refereed
Kishore, R.A.; Mahajan, R.L.; Priya, S. Combinatory Finite Element and Artificial Neural Network Model for Predicting Performance of Thermoelectric Generator. Energies 2018, 11, 2216.
http://hdl.handle.net/10919/85074
https://doi.org/10.3390/en11092216
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/649652023-06-23T15:22:53Zcom_10919_23747com_10919_5539com_10919_23765col_10919_23748col_10919_24353
Plasmonic colorimetric and SERS sensors for environmental analysis
Wei, Haoran
Hossein Abtahi, Seyyed M.
Vikesland, Peter J.
Civil and Environmental Engineering
Institute of Critical Technology and Applied Science
Duke University. Center for the Environmental Implications of Nanotechnology
The potential for water pollution outbreaks requires the development of rapid, yet simple detection methods for water quality monitoring. Plasmonic nanostructures such as gold (AuNPs) and silver (AgNPs) nanoparticles are compelling candidates for the development of highly sensitive biosensors due to their unique localized surface plasmon resonances (LSPRs). The LSPR of AuNPs and AgNPs lies in the visible and infrared light range and is sensitive to the composition, size, shape, surrounding medium, and aggregation state of these NPs. This plasmonic behavior provides the basis for fabrication of colorimetric sensors for environmental analyses. Furthermore, the LSPR also enhances the electromagnetic field near the NP surface, which provides the basis for surface-enhanced Raman spectroscopy (SERS) based detection. Organic or inorganic pollutants and pathogens can be detected and differentiated based upon the finger-print spectra that arise when they enter SERS-active hot spots. In this tutorial review, we summarize progress made towards environmental analysis based on LSPR-based colorimetric and SERS detection. The problems and challenges that have hindered the development of LSPR-based nanosensors for real-world environmental pollutant monitoring are extensively discussed.
2016-03-18
2016-03-18
2015-03-10
2016-03-17
Article - Refereed
Wei, H., Hossein Abtahi, S. M., & Vikesland, P. J. (2015). Plasmonic colorimetric and SERS sensors for environmental analysis. Environmental Science: Nano, 2(2), 120-135. doi:10.1039/C4EN00211C
2051-8153
2015_Wei_Plasmonic_colorimetric_and_SERS_senso.pdf
CBET 1236005
CBET 1133736
EF-0830093
http://hdl.handle.net/10919/64965
https://doi.org/10.1039/C4EN00211C
2
2
en
http://creativecommons.org/licenses/by-nc/3.0/
Creative Commons Attribution-NonCommercial 3.0 Unported
The Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/249592024-02-28T08:02:51Zcom_10919_23747com_10919_5539com_10919_23765com_10919_24369col_10919_23748col_10919_24353col_10919_24370
Role of coexisting tetragonal regions in the rhombohedral phase of Na0.5Bi0.5TiO3-xat.%BaTiO3 crystals on enhanced piezoelectric properties on approaching the morphotropic phase boundary
Yao, Jianjun
Monsegue, Niven
Murayama, Mitsuhiro
Leng, W. N.
Reynolds, William T. Jr.
Zhang, Qinhui
Luo, Haosu
Li, Jiefang
Ge, Wenwei
Viehland, Dwight D.
Civil and Environmental Engineering
Institute for Critical Technology and Applied Science (ICTAS)
Materials Science and Engineering (MSE)
Transmission electron microscopy
Lead-free piezoceramics
Single crystals
Ceramics
Diffraction
Transitions
Strain
Physics
The ferroelectric domain and local structures of Na0.5Bi0.5TiO3-xat.%BaTiO3 (NBT-x%BT) crystals for x = 0, 4.5, and 5.5 have been investigated by transmission electron microscopy. The results show that the size of polar nano-regions was refined with increasing xat. %BT. The tetragonal phase volume fraction, as identified by in-phase octahedral tilting, was found to be increased with BT. The findings indicate that the large electric field induced strains in morphotropic phase boundary compositions of NBT-x%BT originate not only from polarization rotation but also polarization extension. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3673832]
2014-01-21
2014-01-21
2012-01-01
2014-01-10
Article - Refereed
Yao, Jianjun; Monsegue, Niven; Murayama, Mitsuhiro; et al., "Role of coexisting tetragonal regions in the rhombohedral phase of Na0.5Bi0.5TiO3-xat.%BaTiO3 crystals on enhanced piezoelectric properties on approaching the morphotropic phase boundary," Appl. Phys. Lett. 100, 012901 (2012); http://dx.doi.org/10.1063/1.3673832
0003-6951
http://hdl.handle.net/10919/24959
http://scitation.aip.org/content/aip/journal/apl/100/1/10.1063/1.3673832
https://doi.org/10.1063/1.3673832
en
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/889632023-11-29T11:28:12Zcom_10919_25796com_10919_23765col_10919_25797col_10919_24353
Sequence verification of synthetic DNA by assembly of sequencing reads
Wilson, Mandy L.
Cai, Yizhi
Hanlon, Regina
Taylor, Samantha
Chevreux, Bastien
Setubal, Joao C.
Tyler, Brett M.
Peccoud, Jean
gene synthesis
genome
biology
bioinformatics
retrieval
alignment
Gene synthesis attempts to assemble user-defined DNA sequences with base-level precision. Verifying the sequences of construction intermediates and the final product of a gene synthesis project is a critical part of the workflow, yet one that has received the least attention. Sequence validation is equally important for other kinds of curated clone collections. Ensuring that the physical sequence of a clone matches its published sequence is a common quality control step performed at least once over the course of a research project. GenoREAD is a web-based application that breaks the sequence verification process into two steps: the assembly of sequencing reads and the alignment of the resulting contig with a reference sequence. GenoREAD can determine if a clone matches its reference sequence. Its sophisticated reporting features help identify and troubleshoot problems that arise during the sequence verification process. GenoREAD has been experimentally validated on thousands of gene-sized constructs from an ORFeome project, and on longer sequences including whole plasmids and synthetic chromosomes. Comparing GenoREAD results with those from manual analysis of the sequencing data demonstrates that GenoREAD tends to be conservative in its diagnostic. GenoREAD is available at www.genoread.org.
2019-04-15
2019-04-15
2013-01
Article - Refereed
0305-1048
http://hdl.handle.net/10919/88963
https://doi.org/10.1093/nar/gks908
41
1
23042248
1362-4962
en_US
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1007782020-11-24T17:48:13Zcom_10919_19035com_10919_5539com_10919_23765col_10919_24290col_10919_24353
The PathLinker app: Connect the dots in protein interaction networks
Gil, Daniel P.
Law, Jeffrey N.
Murali, T. M.
signaling pathways
pathway reconstruction
protein interaction networks
PathLinker
Cytoscape
k-shortest paths
PathLinker is a graph-theoretic algorithm for reconstructing the interactions in a signaling pathway of interest. It efficiently computes multiple short paths within a background protein interaction network from the receptors to transcription factors (TFs) in a pathway. We originally developed PathLinker to complement manual curation of signaling pathways, which is slow and painstaking. The method can be used in general to connect any set of sources to any set of targets in an interaction network. The app presented here makes the PathLinker functionality available to Cytoscape users. We present an example where we used PathLinker to compute and analyze the network of interactions connecting proteins that are perturbed by the drug lovastatin.
2020-11-03
2020-11-03
2017-01-20
Article - Refereed
Gil DP, Law JN and Murali TM. The PathLinker app: Connect the dots in protein interaction networks [version 1; peer review: 1 approved, 2 approved with reservations] F1000Research 2017, 6:58 https://doi.org/10.12688/f1000research.9909.1
http://hdl.handle.net/10919/100778
https://doi.org/10.12688/f1000research.9909.1
6
58
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
F1000Research
oai:vtechworks.lib.vt.edu:10919/1147622023-04-25T07:13:16Zcom_10919_23829com_10919_5553com_10919_23765col_10919_23830col_10919_24353
The gut microbiome of wild American marten in the Upper Peninsula of Michigan
Lafferty, Diana J. R.
McKenney, Erin A.
Gillman, Sierra J.
Kailing, Chris D.
Walimaa, Myles C.
Kailing, Macy J.
Roell, Brian J.
Trophic relationships
human footprint
conservation
isotopes
delta-c-13
unifrac
number
tools
black
diet
Carnivores are ecologically important and sensitive to habitat loss and anthropogenic disruption. Here we measured trophic level and gut bacterial composition as proxies of carnivore ecological status across the Upper Peninsula, Michigan, for wild American marten (Martes americana; hereafter marten). In contrast to studies that have focused on omnivorous and herbivorous species, we find that marten, like other carnivore species without a cecum, are dominated by Firmicutes (52.35%) and Proteobacteria (45.31%) but lack Bacteroidetes. Additionally, a majority of the 12 major bacterial genera (occurring at >= 1%) are known hydrogen producers, suggesting these taxa may contribute to host energy requirements through fermentative production of acetate. Our study suggests that live trapping and harvest methods yield similar marten gut microbiome data. In addition, preserving undisturbed forest likely impacts marten ecology by measurably increasing marten trophic level and altering the gut microbiome. Our study underscores the utility of the gut microbiome as a tool to monitor the ecological status of wild carnivore populations.
2023-04-24
2023-04-24
2022-11
Article - Refereed
e0275850
http://hdl.handle.net/10919/114762
https://doi.org/10.1371/journal.pone.0275850
17
11
36327319
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Public Library of Science
oai:vtechworks.lib.vt.edu:10919/473872020-10-15T17:45:28Zcom_10919_23765col_10919_24353
Laser-induced exfoliation of amorphous carbon layer on an individual multiwall carbon nanotube
Singh, G.
Rice, P.
Hurst, K. E.
Lehman, John H.
Mahajan, R. L.
purification
vacuum
Pulsed laser treatment of an individual multiwall carbon nanotube induced selective exfoliation of the amorphous carbon contamination layer. The multiwall carbon nanotube (MWCNT) was exposed to a 248 nm excimer laser. After the treatment, transmission electron microscopy images show that the amorphous layer has expanded and separated from the crystalline MWCNT walls. This interesting observation has implications for laser cleaning and possible thinning of MWCNTs to reduce the radial dimensions. (C) 2007 American Institute of Physics.
2014-04-16
2014-04-16
2007-07
2014-03-27
Article - Refereed
Singh, G.; Rice, P.; Hurst, K. E.; et al., "Laser-induced exfoliation of amorphous carbon layer on an individual multiwall carbon nanotube," Appl. Phys. Lett. 91, 033101 (2007); http://dx.doi.org/10.1063/1.2756357
0003-6951
http://hdl.handle.net/10919/47387
http://scitation.aip.org/content/aip/journal/apl/91/3/10.1063/1.2756357
https://doi.org/10.1063/1.2756357
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/1021152022-09-07T14:01:20Zcom_10919_78629com_10919_78628com_10919_111729com_10919_23261com_10919_5539com_10919_18738com_10919_23765com_10919_24369col_10919_79980col_10919_111730col_10919_23145col_10919_24353col_10919_24370
3D printed graphene-based self-powered strain sensors for smart tires in autonomous vehicles
Maurya, Deepam
Khaleghian, Seyedmeysam
Sriramdas, Rammohan
Kumar, Prashant
Kishore, Ravi Anant
Kang, Min-Gyu
Kumar, Vireshwar
Song, Hyun-Cheol
Lee, Seul-Yi
Yan, Yongke
Park, Jung-Min (Jerry)
Taheri, Saied
Priya, Shashank
Mechanical Engineering
Materials Science and Engineering
Electrical and Computer Engineering
Institute for Critical Technology and Applied Science
Center for Tire Research
The transition of autonomous vehicles into fleets requires an advanced control system design that relies on continuous feedback from the tires. Smart tires enable continuous monitoring of dynamic parameters by combining strain sensing with traditional tire functions. Here, we provide breakthrough in this direction by demonstrating tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis. Ink of graphene based material was designed to directly print strain sensor for measuring tire-road interactions under varying driving speeds, normal load, and tire pressure. A secure wireless data transfer hardware powered by a piezoelectric patch is implemented to demonstrate self-powered sensing and wireless communication capability. Combined, this study significantly advances the design and fabrication of cost-effective smart tires by demonstrating practical self-powered wireless strain sensing capability. Designing efficient sensors for smart tires for autonomous vehicles remains a challenge. Here, the authors present a tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis.
2021-01-28
2021-01-28
2020-10-26
Article - Refereed
2041-1723
5392
http://hdl.handle.net/10919/102115
https://doi.org/10.1038/s41467-020-19088-y
11
1
33106481
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1117782022-09-10T07:12:44Zcom_10919_23765com_10919_23261com_10919_5539com_10919_79468com_10919_78628col_10919_24353col_10919_23262col_10919_79481
A Study on Electron Acceptor of Carbonaceous Materials for Highly Efficient Hydrogen Uptakes
Lee, Seul-Yi
Park, Ji-Hye
Heo, Young-Jung
Lee, Eun-Sang
Park, Soo-Jin
hydrogen storage
oxygen-functional groups
porous carbons
pore size
77 K
Significant efforts have been directed toward the identification of carbonaceous materials that can be utilized for hydrogen uptake in order to develop on-board automotive systems with a gravimetric capacity of 5.5 wt.%, thus meeting the U.S. Department of Energy technical targets. However, the capacity of hydrogen storage is limited by the weak interaction between hydrogen molecules and the carbon surface. Cigarette butts, which are the most abundant form of primary plastic waste, remain an intractable environmental pollution problem. To transform this source of waste into a valuable adsorbent for hydrogen uptake, we prepared several forms of oxygen-rich cigarette butt-derived porous carbon (CGB-AC, with the activation temperature range of 600 and 900 & DEG;C). Our experimental investigation revealed that the specific surface area increased from 600 to 700 & DEG;C and then decreased as the temperature rose to 900 & DEG;C. In contrast, the oxygen contents gradually decreased with increasing activation temperature. CGB-AC700 had the highest H-2 excess uptake (QExcess) of 8.54 wt.% at 77 K and 20 bar, which was much higher than that of porous carbon reported in the previous studies. We found that the dynamic interaction between the porosity and the oxygen content determined the hydrogen storage capacity. The underlying mechanisms proposed in the present study would be useful in the design of efficient hydrogen storage because they explain the interaction between positive carbonaceous materials and negative hydrogen molecules in quadrupole orbitals.
2022-09-09
2022-09-09
2021-12
Article - Refereed
1524
http://hdl.handle.net/10919/111778
https://doi.org/10.3390/catal11121524
11
12
2073-4344
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/188962023-05-18T13:28:49Zcom_10919_8195com_10919_25799com_10919_24227com_10919_5532com_10919_23765col_10919_18629col_10919_24302col_10919_24353
Overexpression and simple purification of the Thermotoga maritima 6-phosphogluconate dehydrogenase in Escherichia coli and its application for NADPH regeneration
Wang, Yiran
Zhang, Y. H. Percival
Biological Systems Engineering
Institute for Critical Technology and Applied Science
Background
Thermostable enzymes from thermophilic microorganisms are playing more and more important roles in molecular biology R&D and industrial applications. However, over-production of recombinant soluble proteins from thermophilic microorganisms in mesophilic hosts (e.g. E. coli) remains challenging sometimes.
Results
An open reading frame TM0438 from a hyperthermophilic bacterium Thermotoga maritima putatively encoding 6-phosphogluconate dehydrogenase (6PGDH) was cloned and expressed in E. coli. The purified protein was confirmed to have 6PGDH activity with a molecular mass of 53 kDa. The kcat of this enzyme was 325 s-1 and the Km values for 6-phosphogluconate, NADP+, and NAD+ were 11, 10 and 380 μM, respectively, at 80°C. This enzyme had half-life times of 48 and 140 h at 90 and 80°C, respectively. Through numerous approaches including expression vectors, hosts, cultivation conditions, inducers, and codon-optimization of the 6pgdh gene, the soluble 6PGDH expression levels were enhanced to ~250 mg per liter of culture by more than 500-fold. The recombinant 6PGDH accounted for >30% of total E. coli cellular proteins when lactose was used as a low-cost inducer. In addition, this enzyme coupled with glucose-6-phosphate dehydrogenase for the first time was demonstrated to generate two moles of NADPH per mole of glucose-6-phosphate.
Conclusion
We have achieved a more than 500-fold improvement in the expression of soluble T. maritima 6PGDH in E. coli, characterized its basic biochemical properties, and demonstrated its applicability for NADPH regeneration by a new enzyme cocktail. The methodology for over-expression and simple purification of this thermostable protein would be useful for the production of other thermostable proteins in E. coli.
2012-08-24
2012-08-24
2009-06-04
2012-08-24
Article - Refereed
Microbial Cell Factories. 2009 Jun 04;8(1):30
http://hdl.handle.net/10919/18896
https://doi.org/10.1186/1475-2859-8-30
en
http://creativecommons.org/licenses/by/4.0/
Yiran Wang et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/749942023-06-21T19:15:35Zcom_10919_5com_10919_25799com_10919_8195com_10919_18738com_10919_5539com_10919_23765com_10919_79468com_10919_78628col_10919_70873col_10919_18629col_10919_23145col_10919_24353col_10919_79481
Reduced erbium-doped ceria nanoparticles: one nano-host applicable for simultaneous optical down- and up-conversions
Shehata, Nader
Meehan, Kathleen
Hassounah, Ibrahim
Hudait, Mantu K.
Jain, Nikhil
Clavel, Michael B.
Elhelw, Sarah
Madi, Nabil
Electrical and Computer Engineering
Institute for Critical Technology and Applied Science
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Physics, Applied
Science & Technology - Other Topics
Materials Science
Physics
Ceria nanoparticles
Erbium dopant
Fluorescence
Up-conversion
DISSOLVED-OXYGEN
SOLAR-CELLS
SENSORS
This paper introduces a new synthesis procedure to form erbium-doped ceria nanoparticles (EDC NPs) that can act as an optical medium for both up-conversion and down-conversion in the same time. This synthesis process results qualitatively in a high concentration of Ce3+ ions required to obtain high fluorescence efficiency in the down-conversion process. Simultaneously, the synthesized nanoparticles contain the molecular energy levels of erbium that are required for up-conversion. Therefore, the synthesized EDC NPs can emit visible light when excited with either UV or IR photons. This opens new opportunities for applications where emission of light via both up- and down-conversions from a single nanomaterial is desired such as solar cells and bio-imaging.
2017-02-11
2017-02-11
2014-05-13
Article - Refereed
Nanoscale Research Letters. 2014 May 13;9(1):231
1556-276X
http://hdl.handle.net/10919/74994
https://doi.org/10.1186/1556-276X-9-231
9
en
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000336974100001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://creativecommons.org/licenses/by/4.0/
Nader Shehata et al.; licensee BioMed Central Ltd.
Creative Commons Attribution 4.0 International
Springer
oai:vtechworks.lib.vt.edu:10919/1157712023-07-14T07:12:44Zcom_10919_8195com_10919_25799com_10919_24216com_10919_5539com_10919_23765col_10919_78882col_10919_24286col_10919_24353
Pulsed Electric Fields in Oncology: A Snapshot of Current Clinical Practices and Research Directions from the 4th World Congress of Electroporation
Campana, Luca G.
Daud, Adil
Lancellotti, Francesco
Arroyo, Julio P.
Davalos, Rafael V.
Di Prata, Claudia
Gehl, Julie
The 4th World Congress of Electroporation (Copenhagen, 9–13 October 2022) provided a unique opportunity to convene leading experts in pulsed electric fields (PEF). PEF-based therapies harness electric fields to produce therapeutically useful effects on cancers and represent a valuable option for a variety of patients. As such, irreversible electroporation (IRE), gene electrotransfer (GET), electrochemotherapy (ECT), calcium electroporation (Ca-EP), and tumour-treating fields (TTF) are on the rise. Still, their full therapeutic potential remains underappreciated, and the field faces fragmentation, as shown by parallel maturation and differences in the stages of development and regulatory approval worldwide. This narrative review provides a glimpse of PEF-based techniques, including key mechanisms, clinical indications, and advances in therapy; finally, it offers insights into current research directions. By highlighting a common ground, the authors aim to break silos, strengthen cross-functional collaboration, and pave the way to novel possibilities for intervention. Intriguingly, beyond their peculiar mechanism of action, PEF-based therapies share technical interconnections and multifaceted biological effects (e.g., vascular, immunological) worth exploiting in combinatorial strategies.
2023-07-13
2023-07-13
2023-06-25
2023-07-13
Article - Refereed
Campana, L.G.; Daud, A.; Lancellotti, F.; Arroyo, J.P.; Davalos, R.V.; Di Prata, C.; Gehl, J. Pulsed Electric Fields in Oncology: A Snapshot of Current Clinical Practices and Research Directions from the 4th World Congress of Electroporation. Cancers 2023, 15, 3340.
http://hdl.handle.net/10919/115771
https://doi.org/10.3390/cancers15133340
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/1138172023-02-14T08:11:42Zcom_10919_5com_10919_25799com_10919_23747com_10919_5539com_10919_18738com_10919_23765col_10919_70873col_10919_23748col_10919_23145col_10919_24353
Highly porous gold supraparticles as surface-enhanced Raman spectroscopy (SERS) substrates for sensitive detection of environmental contaminants
Kang, Seju
Wang, Wei
Rahman, Asifur
Nam, Wonil
Zhou, Wei
Vikesland, Peter J.
Nanotechnology
Bioengineering
Surface-enhanced Raman spectroscopy (SERS) has great potential as an analytical technique for environmental analyses. In this study, we fabricated highly porous gold (Au) supraparticles (i.e., ∼100 μm diameter agglomerates of primary nano-sized particles) and evaluated their applicability as SERS substrates for the sensitive detection of environmental contaminants. Facile supraparticle fabrication was achieved by evaporating a droplet containing an Au and polystyrene (PS) nanoparticle mixture on a superamphiphobic nanofilament substrate. Porous Au supraparticles were obtained through the removal of the PS phase by calcination at 500 °C. The porosity of the Au supraparticles was readily adjusted by varying the volumetric ratios of Au and PS nanoparticles. Six environmental contaminants (malachite green isothiocyanate, rhodamine B, benzenethiol, atrazine, adenine, and gene segment) were successfully adsorbed to the porous Au supraparticles, and their distinct SERS spectra were obtained. The observed linear dependence of the characteristic Raman peak intensity for each environmental contaminant on its aqueous concentration reveals the quantitative SERS detection capability by porous Au supraparticles. The limit of detection (LOD) for the six environmental contaminants ranged from ∼10 nM to ∼10 μM, which depends on analyte affinity to the porous Au supraparticles and analyte intrinsic Raman cross-sections. The porous Au supraparticles enabled multiplex SERS detection and maintained comparable SERS detection sensitivity in wastewater influent. Overall, we envision that the Au supraparticles can potentially serve as practical and sensitive SERS devices for environmental analysis applications.
2023-02-13
2023-02-13
2022-11-15
2023-02-12
Article - Refereed
2046-2069
PMC9665105
d2ra06248h (PII)
http://hdl.handle.net/10919/113817
https://doi.org/10.1039/d2ra06248h
12
51
Vikesland, Peter [0000-0003-2654-5132]
Zhou, Wei [0000-0002-5257-3885]
36425178
2046-2069
en
https://www.ncbi.nlm.nih.gov/pubmed/36425178
http://creativecommons.org/licenses/by-nc/4.0/
Creative Commons Attribution-NonCommercial 4.0 International
Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/888742022-03-29T20:31:44Zcom_10919_23765col_10919_24353
Effects of internal electrode cooling on irreversible electroporation using a perfused organ model
O’Brien, T. J.
Bonakdar, Mohammad
Bhonsle, Suyashree P.
Neal, Robert E.
Aardema, C.H.
Robertson, John L.
Goldberg, S.N.
Davalos, Rafael V.
arc mitigation
current
Irreversible electroporation
perfused organ model
Temperature
thermal damage
thermal mitigation
Purpose: This study evaluates the effects of active electrode cooling, via internal fluid circulation, on the irreversible electroporation (IRE) lesion, deployed electric current and temperature changes using a perfused porcine liver model. Materials and methods: A bipolar electrode delivered IRE electric pulses with or without activation of internal cooling to nine porcine mechanically perfused livers. Pulse schemes included a constant voltage, and a preconditioned delivery combined with an arc-mitigation algorithm. After treatment, organs were dissected, and treatment zones were stained using triphenyl-tetrazolium chloride (TTC) to demonstrate viability. Results: Thirty-nine treatments were performed with an internally cooled applicator and 21 with a non-cooled applicator. For the constant voltage scenario, the average final electrical current measured was 26.37 and 29.20 A for the cooled and uncooled electrodes respectively (p≤.001). The average final temperature measured was 33.01 and 42.43 °C for the cooled and uncooled electrodes respectively (p≤.0001). The average measured ablations (fixed lesion) were 3.88-by-2.08 cm and 3.86-by-2.12 cm for the cooled and uncooled electrode respectively (p≤.2495, p≤.7507). Similarly, the preconditioned/arc-mitigation scenario yielded an average final electrical current measurement of a 41.07 and 47.20 A for the cooled and uncooled electrodes respectively (p≤.0001). The average final temperature measured was 34.93 and 44.90 °C for the cooled and uncooled electrodes respectively (p≤.0001). The average measured ablations (fixed lesion) were 3.67-by-2.27 cm and 3.58-by-2.09 cm for the cooled and uncooled applicators ((p≤.7906; p≤.5595)). Conclusions: The internally-cooled bipolar applicator offers advantages that could improve clinical outcomes. Thermally mitigating internal perfusion technology reduced tissue temperatures and electric current while maintaining similar lesion sizes.
2019-04-09
2019-04-09
2018-05-28
Article - Refereed
0265-6736
http://hdl.handle.net/10919/88874
https://doi.org/10.1080/02656736.2018.1473893
35
1
29806513
en_US
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Taylor and Francis Ltd
oai:vtechworks.lib.vt.edu:10919/966822023-11-29T19:15:13Zcom_10919_5540com_10919_24259com_10919_5559com_10919_24209com_10919_5553com_10919_24233com_10919_5532com_10919_23765com_10919_24369com_10919_5539col_10919_71752col_10919_24342col_10919_24267col_10919_24308col_10919_24353col_10919_24370col_10919_23146
Pulmonary Exposure to Magnéli Phase Titanium Suboxides Results in Significant Macrophage Abnormalities and Decreased Lung Function
McDaniel, Dylan K.
Ringel-Scaia, Veronica M.
Morrison, Holly A.
Coutermarsh-Ott, Sheryl
Council-Troche, McAlister
Angle, Jonathan W.
Perry, Justin B.
Davis, Grace
Leng, Weinan
Minarchick, Valerie
Yang, Yi
Chen, Bo
Reece, Sky W.
Brown, David A.
Cecere, Thomas E.
Brown, Jared M.
Gowdy, Kymberly M.
Hochella, Michael F. Jr.
Allen, Irving C.
Biomedical Sciences and Pathobiology
Geosciences
Human Nutrition, Foods, and Exercise
Institute for Critical Technology and Applied Science
Materials Science and Engineering
Virginia-Maryland College of Veterinary Medicine
cytotoxicity
air pollution
nanoparticle
TixO2x−1
in vivo
environmental exposure
Coal is one of the most abundant and economic sources for global energy production. However, the burning of coal is widely recognized as a significant contributor to atmospheric particulate matter linked to deleterious respiratory impacts. Recently, we have discovered that burning coal generates large quantities of otherwise rare Magnéli phase titanium suboxides from TiO2 minerals naturally present in coal. These nanoscale Magnéli phases are biologically active without photostimulation and toxic to airway epithelial cells in vitro and to zebrafish in vivo. Here, we sought to determine the clinical and physiological impact of pulmonary exposure to Magnéli phases using mice as mammalian model organisms. Mice were exposed to the most frequently found Magnéli phases, Ti6O11, at 100 parts per million (ppm) via intratracheal administration. Local and systemic titanium concentrations, lung pathology, and changes in airway mechanics were assessed. Additional mechanistic studies were conducted with primary bone marrow derived macrophages. Our results indicate that macrophages are the cell type most impacted by exposure to these nanoscale particles. Following phagocytosis, macrophages fail to properly eliminate Magnéli phases, resulting in increased oxidative stress, mitochondrial dysfunction, and ultimately apoptosis. In the lungs, these nanoparticles become concentrated in macrophages, resulting in a feedback loop of reactive oxygen species production, cell death, and the initiation of gene expression profiles consistent with lung injury within 6 weeks of exposure. Chronic exposure and accumulation of Magnéli phases ultimately results in significantly reduced lung function impacting airway resistance, compliance, and elastance. Together, these studies demonstrate that Magnéli phases are toxic in the mammalian airway and are likely a significant nanoscale environmental pollutant, especially in geographic regions where coal combustion is a major contributor to atmospheric particulate matter.
2020-02-03
2020-02-03
2019-11-28
Article - Refereed
McDaniel DK, Ringel-Scaia VM, Morrison HA, Coutermarsh-Ott S, Council-Troche M, Angle JW, Perry JB, Davis G, Leng W, Minarchick V, Yang Y, Chen B, Reece SW, Brown DA, Cecere TE, Brown JM, Gowdy KM, Hochella MF Jr and Allen IC (2019) Pulmonary Exposure to Magnéli Phase Titanium Suboxides Results in Significant Macrophage Abnormalities and Decreased Lung Function. Front. Immunol. 10:2714. doi: 10.3389/fimmu.2019.02714
http://hdl.handle.net/10919/96682
https://doi.org/10.3389/fimmu.2019.02714
10
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Frontiers
oai:vtechworks.lib.vt.edu:10919/863452023-07-13T12:32:39Zcom_10919_24214com_10919_5539com_10919_19035com_10919_23765com_10919_23274com_10919_24213com_10919_5553col_10919_24288col_10919_24290col_10919_24353col_10919_23275col_10919_24334
Transcriptomic Analysis of Hepatic Cells in Multicellular Organotypic Liver Models
Tegge, Allison N.
Rodrigues, Richard R.
Larkin, Adam L.
Vu, Lucas T.
Murali, T. M.
Rajagopalan, Padmavathy
Chemical Engineering
Computer Science
Statistics
Institute for Critical Technology and Applied Science
Biomedical Engineering and Sciences
sinusoidal endothelial-cells
activated receptor-alpha
fatty-acid oxidation
cultured primary hepatocytes
phenotype in-vitro
peroxisome-proliferator
ppar-alpha
kupffer cells
gene-expression
beta-oxidation
Liver homeostasis requires the presence of both parenchymal and non-parenchymal cells (NPCs). However, systems biology studies of the liver have primarily focused on hepatocytes. Using an organotypic three-dimensional (3D) hepatic culture, we report the first transcriptomic study of liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs) cultured with hepatocytes. Through computational pathway and interaction network analyses, we demonstrate that hepatocytes, LSECs and KCs have distinct expression profiles and functional characteristics. Our results show that LSECs in the presence of KCs exhibit decreased expression of focal adhesion kinase (FAK) signaling, a pathway linked to LSEC dedifferentiation. We report the novel result that peroxisome proliferator-activated receptor alpha (PPAR alpha) is transcribed in LSECs. The expression of downstream processes corroborates active PPAR alpha signaling in LSECs. We uncover transcriptional evidence in LSECs for a feedback mechanism between PPAR alpha and farnesoid X-activated receptor (FXR) that maintains bile acid homeostasis; previously, this feedback was known occur only in HepG2 cells. We demonstrate that KCs in 3D liver models display expression patterns consistent with an anti-inflammatory phenotype when compared to monocultures. These results highlight the distinct roles of LSECs and KCs in maintaining liver function and emphasize the need for additional mechanistic studies of NPCs in addition to hepatocytes in liver-mimetic microenvironments.
2018-12-11
2018-12-11
2018-07-27
Article - Refereed
2045-2322
11306
http://hdl.handle.net/10919/86345
https://doi.org/10.1038/s41598-018-29455-x
8
30054499
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Springer Nature
oai:vtechworks.lib.vt.edu:10919/233112023-11-29T19:15:39Zcom_10919_78629com_10919_78628com_10919_5540com_10919_23765com_10919_23261com_10919_5539com_10919_23274col_10919_78630col_10919_71752col_10919_24353col_10919_23262col_10919_23275
Towards the development of latent heat storage electrodes for electroporation-based therapies
Arena, Christopher B.
Mahajan, Roop L.
Rylander, M. Nichole
Davalos, Rafael V.
Mechanical Engineering
Institute for Critical Technology and Applied Science
School of Biomedical Engineering and Sciences
Biological tissues
Biomedical electrodes
Biomedical materials
Biothermics
Latent heat
Needles
Numerical analysis
Phase change materials
Phase change materials (PCMs) capable of storing a large amount of heat upon transitioning from the solid-to-liquid state have been widely used in the electronics and construction industries for mitigating temperature development. Here, we show that they are also beneficial for reducing the peak tissue temperature during electroporation-based therapies. A numerical model is developed of irreversible electroporation (IRE) performed with hollow needle electrodes filled with a PCM. Results indicate that this electrode design can be utilized to achieve large ablation volumes while reducing the probability for thermal damage.
2013-07-18
2013-07-18
2012-08-22
Article - Refereed
Marissa Nichole; et al., "Towards the development of latent heat storage electrodes for electroporation-based therapies," Appl. Phys. Lett. 101, 083902 (2012); http://dx.doi.org/10.1063/1.4747332
1077-3118
http://hdl.handle.net/10919/23311
https://doi.org/10.1063/1.4747332
http://scitation.aip.org/content/aip/journal/apl/101/8/10.1063/1.4747332
en
Applied Physics Letters;Volume 101, Issue 8
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
American Institute of Physics
oai:vtechworks.lib.vt.edu:10919/479832022-02-26T15:58:53Zcom_10919_78629com_10919_78628com_10919_24216com_10919_5539com_10919_24259com_10919_5559com_10919_24233com_10919_5532com_10919_23765com_10919_23274col_10919_78630col_10919_24286col_10919_24342col_10919_24308col_10919_24353col_10919_23275
Investigating dielectric properties of different stages of syngeneic murine ovarian cancer cells
Salmanzadeh, Alireza
Sano, Michael B.
Gallo-Villanueva, R. C.
Roberts, Paul C.
Schmelz, Eva M.
Davalos, Rafael V.
Biomedical Engineering and Mechanics
Biomedical Sciences and Pathobiology
Human Nutrition, Foods, and Exercise
Institute for Critical Technology and Applied Science
School of Biomedical Engineering and Sciences
Bioelectric phenomena
Biomedical measurement
Biomembranes
Biomems
Cancer
Capacitance
Cellular biophysics
Electrophoresis
Microfluidics
Contactless dielectrophoresis
Continuous separation
Blood
Electrorotation
Spectroscopy
Frequencies
Membranes
Bacteria
Progress
Spectra
Biophysics
Nanoscience & nanotechnology
Physics, fluids & plasmas
In this study, the electrical properties of four different stages of mouse ovarian surface epithelial (MOSE) cells were investigated using contactless dielectrophoresis (cDEP). This study expands the work from our previous report describing for the first time the crossover frequency and cell specific membrane capacitance of different stages of cancer cells that are derived from the same cell line. The specific membrane capacitance increased as the stage of malignancy advanced from 15.39 +/- 1.54 mF m(-2) for a non-malignant benign stage to 26.42 +/- 1.22 mF m(-2) for the most aggressive stage. These differences could be the result of morphological variations due to changes in the cytoskeleton structure, specifically the decrease of the level of actin filaments in the cytoskeleton structure of the transformed MOSE cells. Studying the electrical properties of MOSE cells provides important information as a first step to develop cancer-treatment techniques which could partially reverse the cytoskeleton disorganization of malignant cells to a morphology more similar to that of benign cells. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4788921] Actual pdf downloaded from NCBI.
2014-05-14
2014-05-14
2013-01-01
2014-05-09
Article - Refereed
Salmanzadeh, A.; Sano, M. B.; Gallo-Villanueva, R. C.; Roberts, P. C.; Schmelz, E. M.; Davalos, R. V., "Investigating dielectric properties of different stages of syngeneic murine ovarian cancer cells," Biomicrofluidics 7, 011809 (2013); http://dx.doi.org/10.1063/1.4788921
1932-1058
http://hdl.handle.net/10919/47983
http://scitation.aip.org/content/aip/journal/bmf/7/1/10.1063/1.4788921
https://doi.org/10.1063/1.4788921
en
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
American Institute of Physics
oai:vtechworks.lib.vt.edu:10919/473862022-11-01T17:33:50Zcom_10919_24216com_10919_5539com_10919_112356com_10919_23261com_10919_23765col_10919_24286col_10919_112358col_10919_24353
Large piezoresistivity phenomenon in SiCN-(La,Sr)MnO3 composites
Karmarkar, Makarand
Singh, Gurpreet
Shah, Sandeep
Mahajan, Roop L.
Priya, Shashank
Center for Energy Harvesting Materials and Systems (CEHMS)
Biomedical Engineering and Mechanics
Institute for Critical Technology and Applied Science
Bond lengths
Composite materials
Lanthanum compounds
Piezoresistance
Scanning electron microscopy
Self-assembly
Silicon compounds
Strontium compounds
Transmission electron microscopy
Ceramics
We present the results on SiCN-(La,Sr)MnO3 (LSMO) composites correlating the observed large piezoresistance behavior with the microstructural features and defect chemistry. Scanning electron microscopy characterization revealed the presence of self-assembled periodic microvalleys in the microstructure with width of 1-5 mu m and depth of 600-1000 nm. The microvalleys act as stress concentration points providing change in volume with applied stress. High resolution transmission electron microscopy measurements conducted on composites showed that LSMO grains consist of SiCN phase but no inclusions were observed.
2014-04-16
2014-04-16
2009-02-01
2014-03-27
Article - Refereed
Karmarkar, Makarand; Singh, Gurpreet; Shah, Sandeep; et al., "Large piezoresistivity phenomenon in SiCN-(La,Sr)MnO3 composites," Appl. Phys. Lett. 94, 072902 (2009); http://dx.doi.org/10.1063/1.3078271
0003-6951
http://hdl.handle.net/10919/47386
http://scitation.aip.org/content/aip/journal/apl/94/7/10.1063/1.3078271
https://doi.org/10.1063/1.3078271
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/496442020-10-15T17:45:29Zcom_10919_23765col_10919_24353
Three-Dimensional Characterization of Iron Oxide (alpha-Fe2O3) Nanoparticles: Application of a Compressed Sensing Inspired Reconstruction Algorithm to Electron Tomography
Monsegue, N.
Jin, X.
Echigo, T.
Wang, G.
Murayama, Mitsuhiro
computed tomography
stem
compressed sensing
3d reconstruction
quantification
hematite
materials science, multidisciplinary
microscopy
In this article, we demonstrate the application of a new compressed sensing three-dimensional reconstruction algorithm for electron tomography that increases the accuracy of morphological characterization of nanostructured materials such as nanocrystalline iron oxide particles. A powerful feature of the algorithm is an anisotropic total variation norm for the L1 minimization during algebraic reconstruction that effectively reduces the elongation artifacts caused by limited angle sampling during electron tomography. The algorithm provides faithful morphologies that have not been feasible with existing techniques.
2014-07-21
2014-07-21
2012-12
2014-07-15
Article - Refereed
Monsegue, N.; Jin, X.; Echigo, T.; Wang, G.; Murayama, M., "Three-Dimensional Characterization of Iron Oxide (alpha-Fe2O3) Nanoparticles: Application of a Compressed Sensing Inspired Reconstruction Algorithm to Electron Tomography," Microsc. Microanal. 18, 1362-1367, 2012. DOI: 10.1017/s1431927612013530
1431-9276
http://hdl.handle.net/10919/49644
http://journals.cambridge.org/action/displayFulltext?type=1&fid=8788485&jid=MAM&volumeId=18&issueId=06&aid=8788483&bodyId=&membershipNumber=&societyETOCSession=
https://doi.org/10.1017/s1431927612013530
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
Cambridge University Press
oai:vtechworks.lib.vt.edu:10919/736432024-03-13T14:09:53Zcom_10919_5com_10919_25799com_10919_23829com_10919_5553com_10919_25796com_10919_23765com_10919_24213col_10919_70873col_10919_23830col_10919_25797col_10919_24353col_10919_24334
Measurement and modeling of transcriptional noise in the cell cycle regulatory network
Ball, David A.
Adames, Neil R.
Reischmann, Nadine
Barik, Debashis
Franck, Christopher T.
Tyson, John J.
Peccoud, Jean
Biological Sciences
Statistics
Fralin Life Sciences Institute
Institute for Critical Technology and Applied Science
Cell Biology
cell cycle
stochastic modeling
gene expression noise
Saccharomyces
cerevisiae
single mRNA FISH
MESSENGER-RNA DECAY
MITOTIC-EXIT CONTROL
GENE-EXPRESSION
BUDDING YEAST
SACCHAROMYCES-CEREVISIAE
SIZE CONTROL
PROTEIN
STOCHASTICITY
FEEDBACK
DYNAMICS
Fifty years of genetic and molecular experiments have revealed a wealth of molecular interactions involved in the control of cell division. In light of the complexity of this control system, mathematical modeling has proved useful in analyzing biochemical hypotheses that can be tested experimentally. Stochastic modeling has been especially useful in understanding the intrinsic variability of cell cycle events, but stochastic modeling has been hampered by a lack of reliable data on the absolute numbers of mRNA molecules per cell for cell cycle control genes. To fill this void, we used fluorescence in situ hybridization (FISH) to collect single molecule mRNA data for 16 cell cycle regulators in budding yeast, Saccharomyces cerevisiae. From statistical distributions of single-cell mRNA counts, we are able to extract the periodicity, timing, and magnitude of transcript abundance during the cell cycle. We used these parameters to improve a stochastic model of the cell cycle to better reflect the variability of molecular and phenotypic data on cell cycle progression in budding yeast.
2016-12-09
2016-12-09
2013-10-01
Article - Refereed
1538-4101
http://hdl.handle.net/10919/73643
https://doi.org/10.4161/cc.26257
12
19
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000327381700014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
Landes Bioscience
oai:vtechworks.lib.vt.edu:10919/249352022-02-26T22:29:12Zcom_10919_23765com_10919_24211com_10919_5553col_10919_24353col_10919_24287
Dynamics of photoexcited carriers and spins in InAsP ternary alloys
Meeker, M. A.
Magill, Brenden A.
Merritt, T. R.
Bhowmick, M.
McCutcheon, K.
Khodaparast, Giti A.
Tischler, J. G.
McGill, S.
Choi, S. G.
Palmstrom, C. J.
Physics
Institute for Critical Technology and Applied Science
relaxation
Physics
The recent rapid progress in the field of spintronics involves extensive measurements of carrier and spin relaxation dynamics in III-V semiconductors. In addition, as the switching rates in devices are pushed to higher frequencies, it is important to understand carrier dynamic phenomena in semiconductors on femtosecond time-scales. In this work, we employed time and spin resolved differential transmission measurements; to probe carrier and spin relaxation times in several InAsP ternary alloys. Our results demonstrate the sensitivity of the spin and carrier dynamics in this material system to the excitation wavelengths, the As concentrations, and temperature. (C) 2013 AIP Publishing LLC.
2014-01-21
2014-01-21
2013-06
2014-01-10
Article - Refereed
Meeker, M. A.; Magill, B. A.; Merritt, T. R.; et al., "Dynamics of photoexcited carriers and spins in InAsP ternary alloys," Appl. Phys. Lett. 102, 222102 (2013); http://dx.doi.org/10.1063/1.4808346
0003-6951
http://hdl.handle.net/10919/24935
http://scitation.aip.org/content/aip/journal/apl/102/22/10.1063/1.4808346
https://doi.org/10.1063/1.4808346
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/933062020-10-15T17:45:16Zcom_10919_23765col_10919_24353
Continuous synthesis of Zn2Al-CO3 layered double hydroxides: a comparison of bench, pilot and industrial scale syntheses
Clark, Ian
Gomes, Rachel Louise
Crawshaw, C.
Neve, L.
Lodge, Rhys
Fay, Michael
Winkler, C.
Hull, Matthew S.
Lester, Ed
Zn2Al-CO3 was produced continuously at bench (g h(-1)), pilot (100s g h -1) and industrial scale (10s kg h(-1)). Crystal domain length and BET surface area were similar at all three scales although there was a small increase at pilot scale. Platelet size increased from 120 nm at bench to 177 nm and 165 nm at pilot scale and industrial scale, respectively. Overall this paper shows that the increase in scale by almost 2000x does not impact on the overall product quality which is an excellent indicator that continuous hydrothermal synthesis is a route for nanomaterials synthesis.
2019-08-29
2019-08-29
2019-04-01
Article - Refereed
2058-9883
http://hdl.handle.net/10919/93306
https://doi.org/10.1039/c8re00241j
4
4
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
oai:vtechworks.lib.vt.edu:10919/1031962021-05-06T07:11:39Zcom_10919_24216com_10919_5539com_10919_23765col_10919_24286col_10919_24353
Bubble cloud behavior and ablation capacity for histotripsy generated from intrinsic or artificial cavitation nuclei
Edsall, Connor
Khan, Zerin Mahzabin
Mancia, Lauren
Hall, Sarah
Mustafa, Waleed
Johnsen, Eric
Klibanov, Alexander L.
Durmaz, Yasemin Yuksel
Vlaisavljevich, Eli
Biomedical Engineering and Mechanics
Institute for Critical Technology and Applied Science
Histotripsy
Microtripsy
Nanoparticles
Microbubbles
Cavitation
Ablation
The study described here examined the effects of cavitation nuclei characteristics on histotripsy. High-speed optical imaging was used to compare bubble cloud behavior and ablation capacity for histotripsy generated from intrinsic and artificial cavitation nuclei (gas-filled microbubbles, fluid-filled nanocones). Results showed a significant decrease in the cavitation threshold for microbubbles and nanocones compared with intrinsic-nuclei controls, with predictable and well-defined bubble clouds generated in all cases. Red blood cell experiments showed complete ablations for intrinsic and nanocone phantoms, but only partial ablation in microbubble phantoms. Results also revealed a lower rate of ablation in artificial-nuclei phantoms because of reduced bubble expansion (and corresponding decreases in stress and strain). Overall, this study demonstrates the potential of using artificial nuclei to reduce the histotripsy cavitation threshold while highlighting differences in the bubble cloud behavior and ablation capacity that need to be considered in the future development of these approaches. (E-mail: cwedsall@vt.edu) (C) 2020 The Author(s). Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.
2021-05-05
2021-05-05
2021-03
Article - Refereed
0301-5629
http://hdl.handle.net/10919/103196
https://doi.org/10.1016/j.ultrasmedbio.2020.10.020
47
3
1879-291X
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
oai:vtechworks.lib.vt.edu:10919/251722020-10-15T17:45:30Zcom_10919_23765col_10919_24353
Frequency-dependent stability of parallel-plate electrostatic actuators in conductive fluids
Sounart, T. L.
Panchawagh, H. V.
Mahajan, R. L.
dielectric materials
electrostatic actuators
mechanical stability
microfluidics
mems
design
Physics
We present an electromechanical stability analysis of passivated parallel-plate electrostatic actuators in conductive dielectric media and show that the pull-in instability can be eliminated by tuning the applied frequency below a design-dependent stability limit. A partial instability region is also obtained, where the actuator jumps from the pull-in displacement to another stable position within the gap. The results predict that the stability limit is always greater than the critical actuation frequency, and therefore any device that is feasible to actuate in a conductive fluid can be operated with stability over the full range of motion. (C) 2010 American Institute of Physics. [doi:10.1063/1.3389491]
2014-01-28
2014-01-28
2010-05
2014-01-17
Article - Refereed
Sounart, T. L.; Panchawagh, H. V.; Mahajan, R. L., "Frequency-dependent stability of parallel-plate electrostatic actuators in conductive fluids," Appl. Phys. Lett. 96, 203505 (2010); http://dx.doi.org/10.1063/1.3389491
0003-6951
http://hdl.handle.net/10919/25172
http://scitation.aip.org/content/aip/journal/apl/96/20/10.1063/1.3389491
https://doi.org/10.1063/1.3389491
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
AIP Publishing
oai:vtechworks.lib.vt.edu:10919/875382022-11-01T17:33:50Zcom_10919_112356com_10919_23261com_10919_5539com_10919_23765col_10919_112358col_10919_24353
Giant piezoelectric voltage coefficient in grain-oriented modified PbTiO3 material
Yan, Yongke
Zhou, Jie E.
Maurya, Deepam
Wang, Yu U.
Priya, Shashank
A rapid surge in the research on piezoelectric sensors is occurring with the arrival of the Internet of Things. Single-phase oxide piezoelectric materials with giant piezoelectric voltage coefficient (g, induced voltage under applied stress) and high Curie temperature (T-c) are crucial towards providing desired performance for sensing, especially under harsh environmental conditions. Here, we report a grain-oriented (with 95% <001> texture) modified PbTiO3 ceramic that has a high T-c (364 degrees C) and an extremely large g(33) (115 x 10(-3) Vm N-1) in comparison with other known single-phase oxide materials. Our results reveal that self-polarization due to grain orientation along the spontaneous polarization direction plays an important role in achieving large piezoelectric response in a domain motion-confined material. The phase field simulations confirm that the large piezoelectric voltage coefficient g(33) originates from maximized piezoelectric strain coefficient d(33) and minimized dielectric permittivity epsilon(33) in [001]-textured PbTiO3 ceramics where domain wall motions are absent.
2019-02-08
2019-02-08
2016-10-11
Article - Refereed
2041-1723
13089
http://hdl.handle.net/10919/87538
https://doi.org/10.1038/ncomms13089
7
27725634
en_US
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Springer Nature
oai:vtechworks.lib.vt.edu:10919/520162020-12-08T20:58:07Zcom_10919_23765col_10919_24353
High-performance carbon nanotube coatings for high-power laser radiometry
Ramadurai, Krishna
Cromer, Christopher L.
Lewis, Laurence A.
Hurst, Katherine E.
Dillon, Anne C.
Mahajan, Roop L.
Lehman, John H.
Carbon nanotubes
Carbon
Irradiance
Metallic coatings
Optical coatings
Radiometry for the next generation of high-efficiency, high-power industrial lasers requires thermal management at optical power levels exceeding 10 kW. Laser damage and thermal transport present fundamental challenges for laser radiometry in support of common manufacturing processes, such as welding, cutting, ablation, or vaporization. To address this growing need for radiometry at extremely high power densities, we demonstrate multiwalled carbon nanotube (MWCNT) coatings with damage thresholds exceeding 15 000 W/cm(2) and absorption efficiencies over 90% at 1.06 mu m. This result demonstrates specific design advantages not possible with other contemporary high-power laser coatings. Furthermore, the results demonstrate a performance difference between MWCNTs and single-walled carbon nanotube coatings, which is attributed to the lower net thermal resistance of the MWCNT coatings. We explore the behavior of carbon nanotubes at two laser wavelengths (1.06 and 10.6 mu m) and also evaluate the optical-absorption efficiency and bulk properties of the coatings. (c) 2008 American Institute of Physics.
2015-05-05
2015-05-05
2008-01-01
2015-04-24
Article - Refereed
Journal of Applied Physics 103, 013103 (2008); doi: 10.1063/1.2825647
0021-8979
http://hdl.handle.net/10919/52016
http://scitation.aip.org/content/aip/journal/jap/103/1/10.1063/1.2825647
https://doi.org/10.1063/1.2825647
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
American Institute of Physics
oai:vtechworks.lib.vt.edu:10919/791502022-03-20T20:05:43Zcom_10919_8195com_10919_25799com_10919_24227com_10919_5532com_10919_23765col_10919_78882col_10919_24302col_10919_24353
Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy
Zhang, Y. H. Percival
Mielenz, Jonathan R.
Biological Systems Engineering
Institute for Critical Technology and Applied Science
artificial photosynthesis
carbohydrate economy
carbon dioxide utilization
hydrogen carrier
hydrogen production
cell-free synthetic pathway biotransformation (SyPaB)
The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology—cell-free synthetic pathway biotransformation (SyPaB). Assembly of numerous enzymes and co-enzymes <em>in vitro</em> can create complicated set of biological reactions or pathways that microorganisms or catalysts cannot complete, for example, C<sub>6</sub>H<sub>10</sub>O<sub>5</sub> (aq) + 7 H<sub>2</sub>O (l) à 12 H<sub>2</sub> (g) + 6 CO<sub>2</sub> (g) (PLoS One 2007, 2:e456). Thanks to 100% selectivity of enzymes, modest reaction conditions, and high-purity of generated hydrogen, carbohydrate is a promising hydrogen carrier for end users. Gravimetric density of carbohydrate is 14.8 H<sub>2</sub> mass% if water can be recycled from proton exchange membrane fuel cells or 8.33% H<sub>2</sub> mass% without water recycling. Renewable carbohydrate can be isolated from plant biomass or would be produced from a combination of solar electricity/hydrogen and carbon dioxide fixation mediated by high-efficiency artificial photosynthesis mediated by SyPaB. The construction of this carbon-neutral carbohydrate economy would address numerous sustainability challenges, such as electricity and hydrogen storage, CO<sub>2</sub> fixation and long-term storage, water conservation, transportation fuel production, plus feed and food production.
2017-09-20
2017-09-20
2011-01-31
2017-09-20
Article - Refereed
Zhang, Y.-H.; Mielenz, J.R. Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy. Energies 2011, 4, 254-275.
http://hdl.handle.net/10919/79150
https://doi.org/10.3390/en4020254
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
MDPI
oai:vtechworks.lib.vt.edu:10919/253962020-10-15T17:45:23Zcom_10919_23765com_10919_24369com_10919_5539col_10919_24353col_10919_24370
Nanodispersed DO(3)-phase nanostructures observed in magnetostrictive Fe-19% Ga Galfenol alloys
Bhattacharyya, Somnath
Jinschek, J. R.
Khachaturyan, Armen G.
Cao, Hu
Li, Jiefang
Viehland, Dwight D.
Institute for Critical Technology and Applied Science (ICTAS)
Materials Science and Engineering (MSE)
Short-range order
Fe-Ga
AL alloys
State
Phase
Physics
Few nanometer large (<2 nm) inclusions of DO(3)-phase structure have been identified in the A2 matrix of highly magnetostrictive Fe-19% Ga alloys by high-resolution transmission electron microscopy (HRTEM). In addition, we have found that these nanostructures include a high density of {100} line defects with a Burgers vector of a(bcc)/2 < 100 >. This dispersion of DO(3)-phase nanostructures formed within the main A2 matrix and the lifting of their coherency by defects are consistent with a recent theory for the structure and properties of magnetostrictive Fe-Ga and Fe-Al alloys.
2014-02-11
2014-02-11
2008-03-10
2013-12-18
Article - Refereed
Bhattacharyya, Somnath ; Jinschek, J. R. ; Khachaturyan, A. ; et al., Mar 2008. "Nanodispersed DO(3)-phase nanostructures observed in magnetostrictive Fe-19% Ga Galfenol alloys," PHYSICAL REVIEW B 77(10): 104107. DOI: 10.1103/PhysRevB.77.104107
1098-0121
http://hdl.handle.net/10919/25396
http://link.aps.org/doi/10.1103/PhysRevB.77.104107
https://doi.org/10.1103/PhysRevB.77.104107
en_US
http://rightsstatements.org/vocab/InC/1.0/
In Copyright
American Physical Society
oai:vtechworks.lib.vt.edu:10919/775522022-02-26T16:06:55Zcom_10919_78629com_10919_78628com_10919_23765col_10919_78630col_10919_24353
Nanoparticles in road dust from impervious urban surfaces: distribution, identification, and environmental implications
Yang, Yi
Vance, Marina
Tou, Feiyun
Tiwari, Andrea J.
Liu, Min
Hochella, Michael F. Jr.
Center for Sustainable Nanotechnology
Institute for Critical Technology and Applied Science
Geosciences. Center for NanoBioEarth
Nanoparticles (NPs) resulting from urban road dust resuspension are an understudied class of pollutants in urban environments with strong potential for health hazards. The objective of this study was to investigate the heavy metal and nanoparticle content of PM2.5 generated in the laboratory using novel aerosolization of 66 road dust samples collected throughout the mega-city of Shanghai (China). The samples were characterized using an array of techniques including inductively-coupled plasma mass spectrometry, aerosol size distribution measurements, and scanning and transmission electron microscopy coupled with elemental characterization and electron diffraction. Principal metal concentrations were plotted geospatially. Results show that metals were generally enriched in aerosolized samples relative to the bulk dust. Elevated concentrations of metals were found mostly in downtown areas with intense traffic. Fe-, Pb-, Zn-, and Ba-containing NPs were identified using electron microscopy, spectroscopy, and diffraction, and we tentatively identify most of them as either engineered, incidental, or naturally occurring NPs. For example, dangerous Pb sulfide and sulfate NPs likely have an incidental origin and are also sometimes associated with Sn; we believe that these materials originated from an e-waste plant. Size distributions of most aerosolized samples presented a peak in the ultrafine range (<100 nm). We estimate that 3.2 ± 0.7 μg mg−1 of Shanghai road dust may become resuspended in the form of PM2.5. Aerosolization, as done in this study, seems to be a very useful approach to study NPs in dust.
2017-05-01
2017-05-01
2016-05-24
Article - Refereed
2051-8153
http://hdl.handle.net/10919/77552
https://doi.org/10.1039/c6en00056h
3
3
2051-8161
en_US
Royal Society of Chemistry Gold Open Access - 2016
http://creativecommons.org/licenses/by-nc/3.0/
Yang, Yi
Vance, Marina
Tou, Feiyun
Tiwari, Andrea
Liu, Min
Hochella, Michael F.
Creative Commons Attribution-NonCommercial 3.0 Unported
Royal Society of Chemistry
oai:vtechworks.lib.vt.edu:10919/950532020-10-15T17:45:16Zcom_10919_23765col_10919_24353
Nanoparticulate Nickel-Hosting Phases in Sulfidic Environments: Effects of Ferrous Iron and Bacterial Presence on Mineral Formation Mechanism and Solid-Phase Nickel Distribution
Manson, Muammar
Winkler, Christopher
Hochella, Michael F. Jr.
Xu, Jie
nickel sulfides
millerite
polydymite
vaesite
sulfate-reducing bacteria
polyphasic
sulfidic environments
mackinawite
The precipitation of nickel with sulfide is an important process governing the bioavailability of Ni in natural waters, and this process has the potential to effectively remove aqueous Ni contaminants in near-surface environments. In this study, we use experimental approaches to investigate the diversity of Ni-hosting phases precipitated in sulfidic environments across a range of aqueous Ni-to-Fe ratios ([Ni](aq)/[Fe](aq)) and in the presence or absence of the sulfate-reducing bacteria (SRB), Desulfovibrio vulgaris. In the absence of Fe(II), the initial precipitates in abiotic experiments are found to consist primarily of polyphasic Ni-sulfides (average sizes <20 nm) with millerite (trigonal NiS) cores and amorphous shells. The precipitates' crystallinity is enhanced noticeably over a period of similar to 6 days, forming larger-sized hexagonal alpha-NiS, and observations of defects such as twinning and stacking faults implicate a formation pathway via reassembly of fine nanoparticulate precursors. By comparison, in the presence of SRB and in the absence of Fe, more crystalline phases such as polydymite (Ni3S4 ) and vaesite (NiS2) are also precipitated in addition to the monosulfide phases. The observed difference suggests that the presence of SRB enables the transformation of polyphasic precursors to more crystalline structures through the combined effects of bacterial metabolites and localized precipitation within a low pH micro-environment around the cell walls. The addition of Fe(II) (i.e., [Ni](aq)/[Fe](aq) = 5:1) leads to formation of less crystalline Ni-sulfides in both biotic and abiotic systems, indicating crystal structure distortion caused by substitution of Ni with Fe. With decreasing [Ni](aq)/[Fe](aq), Ni-sulfides become rarer, mixed Ni-Fe phases start to appear, and finally Ni-rich mackinawite (FeS) becomes the primary Ni-hosting phase at the lowest ratio tested ([Ni](aq)/[Fe](aq) = 1:5). We propose that whether aqueous Ni forms discrete Ni-S phases or is incorporated into dominantly Fe-S phases is primarily determined by the precipitation kinetics, and our experiments at [Ni](aq)/[Fe](aq) = 1:1 suggest that Ni-sulfide precipitation kinetics is comparable or higher than Fe-sulfides at this condition. Overall, our study allows for prediction on the phases and biogeochemical factors controlling Ni removal and availability in sulfidic environments.
2019-10-25
2019-10-25
2019-06-26
Article - Refereed
2296-6463
UNSP 151
http://hdl.handle.net/10919/95053
https://doi.org/10.3389/feart.2019.00151
7
en
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International
Frontiers
oai:vtechworks.lib.vt.edu:10919/878182023-11-29T15:33:17Zcom_10919_23765com_10919_23261com_10919_5539com_10919_72294col_10919_24353col_10919_23262col_10919_72295
Processing method for grain-oriented lead-free piezoelectric Na0.5Bi0.5TiO3—BaTiO3 ceramics exhibiting giant performance
Mechanical Engineering
Institute for Critical Technology and Applied Science (ICTAS)
Virginia Tech Intellectual Properties, Inc.
Priya, Shashank
Maurya, Deepam
Textured ceramic compositions having improved piezoelectric characteristics as compared with their random counterparts are provided. Methods of making the compositions and devices using them are also included. More particularly, compositions comprising textured ceramic Na0.5Bi0.5TiO3—BaTiO3(NBT-BT) materials synthesized from high aspect ratio NBT seeds exhibit improved characteristics, including an increased longitudinal piezoelectric constant (d33) and magnetoelectric coupling coefficient over randomly oriented NBT-BT. Additionally provided are compositions comprising of nanostructured Na0.5Bi0.5TiO3—BaTiO3 ferroelectric whiskers having a high aspect ratio. Nanostructured whiskers can be used to improve the piezoelectric properties of the bulk ceramics. The inventive materials are useful in microelectronic devices, with some finding particular application as multilayer actuators and transducers.
2019-02-26
2019-02-26
2017-09-26
2019-02-15
2013-10-31
Patent
http://hdl.handle.net/10919/87818
http://pimg-fpiw.uspto.gov/fdd/67/739/097/0.pdf
14068687
9773967
en_US
United States Patent and Trademark Office
oai:vtechworks.lib.vt.edu:10919/1000472023-12-19T13:34:52Zcom_10919_5com_10919_25799com_10919_24259com_10919_5559com_10919_23765com_10919_24261com_10919_51731com_10919_5478col_10919_70873col_10919_24342col_10919_24353col_10919_24343col_10919_51732
Antibacterial efficacy of core-shell nanostructures encapsulating gentamicin against an in vivo intracellular Salmonella model
Ranjan, Ashish
Pothayee, Nikorn
Seleem, Mohamed N.
Tyler, Ronald D.
Brenseke, Bonnie
Sriranganathan, Nammalwar
Riffle, Judy S.
Kasimanickam, Ramanathan K.
Life Sciences & Biomedicine
Nanoscience & Nanotechnology
Pharmacology & Pharmacy
Science & Technology - Other Topics
gentamicin
core-shell nanostructures
Salmonella
PLURONIC(R) BLOCK-COPOLYMERS
INDUCED NEPHROTOXICITY
DRUG-DELIVERY
LIPOSOMES
NANOPARTICLES
NANOCARRIERS
RELEASE
0601 Biochemistry and Cell Biology
1007 Nanotechnology
1115 Pharmacology and Pharmaceutical Sciences
Nanoscience & Nanotechnology
Pluronic based core-shell nanostructures encapsulating gentamicin were designed in this study. Block copolymers of (PAA(+/-)Na-b-(PEO-b-PPO-b-PEO)-b-PAA(+/-)Na) were blended with PAA(-) Na(+) and complexed with the polycationic antibiotic gentamicin to form nanostructures. Synthesized nanostructures had a hydrodynamic diameter of 210 nm, zeta potentials of -0.7 (+/-0.2), and incorporated approximately 20% by weight of gentamicin. Nanostructures upon co-incubation with J774A.1 macrophage cells showed no adverse toxicity in vitro. Nanostructures administered in vivo either at multiple dosage of 5 microg g(-1) or single dosage of 15 microg g(-1) in AJ-646 mice infected with Salmonella resulted in significant reduction of viable bacteria in the liver and spleen. Histopathological evaluation for concentration-dependent toxicity at a dosage of 15 microg g(-1) revealed mineralized deposits in 50% kidney tissues of free gentamicin-treated mice which in contrast was absent in nanostructure-treated mice. Thus, encapsulation of gentamicin in nanostructures may reduce toxicity and improve in vivo bacterial clearance.
2020-09-21
2020-09-21
2009-01-01
2020-09-21
Article - Refereed
1178-2013
http://hdl.handle.net/10919/100047
https://doi.org/10.2147/ijn.s7137
4
Sriranganathan, Nammalwar [0000-0002-9232-2888]
Seleem, Mohamed [0000-0003-0939-0458]
20054433 (pubmed)
1178-2013
en
http://creativecommons.org/licenses/by-nc/4.0/
Creative Commons Attribution-NonCommercial 4.0 International
Dove Medical Press
oai:vtechworks.lib.vt.edu:10919/1112932022-07-20T07:12:08Zcom_10919_78629com_10919_78628com_10919_23765col_10919_78630col_10919_24353
An Emergency Powered Air-Purifying Respirator From Local Materials and its Efficacy Against Aerosolized Nanoparticles
Kessel, Jeff
Saevig, Christopher S.
Hill, W. Cary
Kessel, Benjamin
Hull, Matthew S.
aerosols
COVID-19
head protective devices
healthcare
health personnel
infection control
intubation
nanoparticle
pandemics
powered air-purifying respirators
respiratory protective devices
surgical helmet
We describe an approach used by a rural healthcare provider to convert surgical helmets into emergency powered air-purifying respirators (PAPRs) at the onset of the COVID-19 pandemic. The approach uses common materials and efficacy was demonstrated against aerosols measuring 7 nm to 25 mu m in diameter.
2022-07-19
2022-07-19
2022-03
Article - Refereed
0046-9580
469580221087837
http://hdl.handle.net/10919/111293
https://doi.org/10.1177/00469580221087837
59
35341353
1945-7243
en
http://creativecommons.org/licenses/by-nc/4.0/
Creative Commons Attribution-NonCommercial 4.0 International
Sage Publications Inc