An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
The field of biothermodynamics encompasses physical property measurements on biochemical and biological systems. This chapter reviews the status of standards documents that are pertinent to biothermodynamics as well as recommendations that have been made
Desu Chen, Sumona Sarkar, Stephen J. Florczyk, Subhadip Bodhak, Carl G. Simon Jr., Joy P. Dunkers, Julian Candia, Wolfgang Losert
Cell shape has been demonstrated to be closely related to cell function and may be an important predictor of cell fate. Many metrics are available to describe cell shape, however the relationship of these metrics to cell fate are not well understood
Carl G. Simon Jr., Peter Bajcsy, Wojtek J. Tutak, Jyotsnendu J. Giri
Previous work has demonstrated that culture of osteoprogenitor cells on nanofiber scaffolds can potentiate osteogenic differentiation [1-4]. Culture of cells in nanofiber scaffolds causes changes to cell morphology, suggesting that morphological changes
Sumona Sarkar, Bryan A. Baker, Desu Chen, Wolfgang Losert, Carl G. Simon Jr., Joy P. Dunkers
Nanofiber technology has emerged as a promising tool to recapitulate the native extracellular matrix (ECM) environment for tissue engineering and regenerative medicine strategies. Cell-material interactions in the nanofiber system are largely dependent on
Daneli Lopez-Perez, Nancy J. Lin, Sheng Lin-Gibson
Biofilms have been implicated in 80 % of all chronic human infections1, yet little attention has been focused on studies of antimicrobial agent efficacy in bacterial biofilms. The planktonic state of bacteria is most commonly studied in the literature
Carbamate kinase from Giardia lamblia is an essential enzyme for the survival of the organism. The enzyme catalyzes the final step in the arginine dihydrolase pathway converting ADP and carbamoyl phosphate to ATP and carbamate. We previously reported that
John Bowden, Theresa M. Cantu, Douglas M. Scheidt, Russell H. Lowers, Brian A. Nocito, Vaneica Y. Young, Louis J. Guillette
Metal deposition originating from anthropogenic activity was examined in a two-tier study using environmental samples collected from several locations at the Kennedy Space Center (KSC) and surrounding Merritt Island National Wildlife Refuge (MINWR) with
Carl G. Simon Jr., Sapun Parekh, Christopher K. Tison, Girish Kumar, Tanya M. Farooque, Charles H. Camp
Many 3D scaffold systems have evolved for tissue engineering, drug screening and in vitro tissue models. However, it is not clear which scaffolds provide a 3D cell niche and there is no clear way to measure cell niche dimensionality. Advances in 3D niche
Jessica L. Burger, Hideki Yamamoto, Takamasa Suzuki, Arno D. Laesecke
High concentration DNA solutions are common both in vitro and in vivo, and understanding the rheological properties is a critical area of bioscience. Our previous measurements on high concentration DNA solutions (2-6 mg/ml) interestingly provided evidence
Zvi Kelman, Richard Y. Huang, Zhuo Li, Jerard Hurwitz, Santangelo J. Thomas, Travis H. Hileman, Yopp C. Daniel, Jeffrey W. Hudgens
Chromosomal DNA replication requires the regulated activity of large number of proteins and complexes. Proliferating cell nuclear antigen (PCNA) protein forms a homotrimeric ring that associates with, and regulates the activity of, many proteins
Rick L. Paul, William C. Davis, Karen E. Murphy, Colleen E. Bryan Sallee, Lee L. Yu, William F. Guthrie, Dennis D. Leber, Thomas W. Vetter
A newly developed procedure for determination of arsenic by radiochemical neutron activation analysis was used to measure arsenic in SRM 955c Toxic Elements in Caprine Blood and SRM 2668 Toxic Elements in Frozen Human Urine for the purpose of providing
Paul A. Rudnick, Xinjian Yan, Stephen E. Stein, Xia Wang, Nell Sedransk
Systematic biases, or batch effects, in high-throughput biological datasets can be described as obscuring variabilities introduced during experimental design or analytical processing. These biases, if left unresolved, can lead to misinterpretation of
Justin M. Zook, Brad Chapman, Winston Hide, Marc L. Salit
Clinical adoption of human genome sequencing requires methods that output genotypes with known accuracy at millions or billions of positions across a genome. Because of substantial discordance among calls made by existing sequencing methods and algorithms
Stephen E. Stein, David M. Bunk, Xia Wang, Matthew Chambers, Lorenzo J. Vega-Montoto, David L. Tabb
Shotgun proteomics experiments integrate a complex sequence of processes, any of which can introduce variability. Quality metrics computed from LC-MS/MS data have relied upon identifying MS/MS scans, but a new mode for the QuaMeter software produces
Benjamin B. Parrott, John Bowden, Satomi Kohno, Jessica A. Cloy-McCoy, Jacqueline T. Bangma, Thomas R. Rainwater, Phillip M. Wilkinson, John Kucklick, Louis J. Guillette
Epigenetic modifications are key mediators of the interactions between the environment and an organism's genome. DNA methylation represents the best-studied epigenetic modification to date and is known to play key roles in regulating transcriptional
Steve Y. Rhieu, Aaron A. Urbas, Daniel W. Bearden, John P. Marino, Vytautas Reipa, Katrice A. Lippa
Non-invasive and real-time analysis of cellular redox processes has been greatly hampered by lack of suitable measurement techniques. Here we describe an in-cell nuclear magnetic resonance (NMR)-based method for measuring the intracellular glutathione
Dan Bearden, Douglas W. Lowman, Rachel R. Greene, Michael D. Kruppa, Max Pottier, Mario Monteiro, David L. Williams
The innate immune system differentially recognizes Candida albicans yeast and hyphae. It is not clear how the innate immune system effectively discriminates between yeast and hyphal forms of C. albicans. Glucans are major components of the fungal cell wall
Mark S. Lowenthal, Yuxue Liang, Karen W. Phinney, Stephen E. Stein
Accurate quantification is a fundamental requirement in the fields of proteomics and biomarker discovery, and for clinical diagnostic assays. To demonstrate the extent of quantitative variability in measurable peptide concentrations due to differences
Michael A. Boss, John A. Mates, Sarah E. Busch, Paul SanGiorgio, Stephen E. Russek, Kai Buckenmaier, Kent D. Irwin, Hsiao-Mei Cho, Gene C. Hilton, John Clarke
Purpose: Prototype phantoms were designed, constructed, and characterized for the purpose of calibrating ultralow field magnetic resonance imaging (ULF MRI) systems. The phantoms were designed to measure spatial resolution and to quantify sensitivity to
Carl G. Simon Jr., Wojtek J. Tutak, Sumona Sarkar, Tanya M. Farooque, Jyotsnendu J. Giri, Dongbo Wang, Sheng Lin-Gibson, Joachim Kohn, Durgadas Bolikal
Nanofiber scaffolds are effective for tissue engineering since they emulate the fibrous nanostructure of native extracellular matrix (ECM). Although electrospinning has been the most common approach for fabricating nanofiber scaffolds, airbrushing
John M. Moreland, Yoshihiro Nakashima, Jacob W. Alldredge, Gary Zabow
New instrumentation is being developed to better understand the in vivo properties of magnetic particles suspended in solution or lodged in tissue. We describe three novel methods with the necessary sensitivity to measure the microscopic magnetic
Meiyao Wang, Yang Shen, Illarion Turko, Daniel Nelson, Shuwei Li
Carbapenems are broad spectrum antibiotics considered as last resort drugs to treat bacterial infections. Carbapenem-hydrolyzing β-lactamases (also called carbapenemases), however, can confer bacterial resistance and represent a serious health threat. Here
Stephen E. Stein, Paul A. Rudnick, Scott J. Walmsley, Qian Dong, Alexey I. Nesvizhskii, Yuxue Liang
Trypsin is an endoprotease commonly used for sample preparation in proteomics experiments. Importantly, protein digestion is dependent on multiple factors, including the trypsin origin and digestion conditions. In-depth characterization of trypsin activity