Time filter

Source Type

Honolulu, HI, United States

Nagy K.J.,U.S. National Cancer Institute | Nagy K.J.,University of Delaware | Giano M.C.,U.S. National Cancer Institute | Giano M.C.,University of Delaware | And 3 more authors.
Journal of the American Chemical Society | Year: 2011

Chirality can be used as a design tool to control the mechanical rigidity of hydrogels formed from self-assembling peptides. Hydrogels prepared from enantiomeric mixtures of self-assembling β-hairpins show nonadditive, synergistic, enhancement in material rigidity compared to gels prepared from either pure enantiomer, with the racemic hydrogel showing the greatest effect. CD spectroscopy, TEM, and AFM indicate that this enhancement is defined by nanoscale interactions between enantiomers in the self-assembled state. © 2011 American Chemical Society. Source

Kainerstorfer J.M.,Eunice Kennedy Shriver National Institute of Child Health and Human Development | Smith P.D.,Cellular Bioengineering | Gandjbakhche A.H.,Eunice Kennedy Shriver National Institute of Child Health and Human Development
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2012

Imaging of large tissue areas (>5 cm 2) is often desired in clinical settings, e.g., of tissue oxygenation. Intrinsic contrasts such as absorption and scattering changes have the potential to enhance diagnostics and help monitor diseased tissue. An overview of existing noncontact multispectral diffuse reflectance imaging modalities for tissue characterization based on intrinsic optical contrast due to absorption and scattering properties of tissue is given here. Also, an overview of instrumentation advances, modeling approaches, applications, and ongoing work is described, primarily in, but not limited to, skin imaging, demonstrating the benefits and limitations of wide-field diffuse reflectance imaging. © 2012 IEEE. Source

Torrents E.,University of Stockholm | Torrents E.,Cellular Bioengineering | Sjoberg B.-M.,University of Stockholm
Biological Chemistry | Year: 2010

Bacillus anthracis is a severe mammalian pathogen. The deoxyribonucleotides necessary for DNA replication and repair are provided via the ribonucleotide reductase (RNR) enzyme. RNR is also important for spore germination and cell proliferation upon infection. We show that the expression of B. anthracis class Ib RNR responds to the environment that the pathogen encounters upon infection. We also show that several anti-proliferative agents (radical scavengers) specifically inhibit the B. anthracis RNR. Owing to the importance of RNR in the pathogenic infection process, our results highlight a promising potential to inhibit the growth of B. anthracis early during infection. © 2010 by Walter de Gruyter Berlin New York. Source

Zhao H.,Cellular Bioengineering | Ghirlando R.,U.S. National Institute of Diabetes and Digestive and Kidney Diseases | Piszczek G.,U.S. National Institutes of Health | Curth U.,Hannover Medical School | And 2 more authors.
Analytical Biochemistry | Year: 2013

We report systematic and large inaccuracies in the recorded elapsed time in data files from the analytical ultracentrifuge, leading to overestimates of the sedimentation coefficients of up to 10%. This far exceeds previously considered factors contributing to the uncertainty in this parameter and has significant ramifications for derived parameters such as hydrodynamic shape and molar mass estimates. The source of this error is currently unknown, but we found it to be quantitatively consistent across different instruments, increasing with rotor speed. Furthermore, its occurrence appears to correlate with the use of the latest data acquisition software from the manufacturer, in use in some of our laboratories for nearly 2 years. Many of the recently published sedimentation coefficients may need to be reexamined. The problem can be easily recognized by comparing the file timestamps provided by the operating system with the elapsed scan times recorded within the data files. Therefore, we implemented a routine in SEDFIT that can automatically examine the data files, alert the user to significant discrepancies, and correct the scan times accordingly. This eliminates errors in the recorded scan times. © 2013 Elsevier Inc. All rights reserved. Source

Cendra M.d.M.,Cellular Bioengineering | Juarez A.,Cellular Bioengineering | Juarez A.,University of Barcelona | Torrents E.,Cellular Bioengineering
PLoS ONE | Year: 2012

Ribonucleotide reductase (RNR) is an essential enzyme for all living organisms since is the responsible for the last step in the synthesis of the four deoxyribonucleotides (dNTPs) necessary for DNA replication and repair. In this work, we have investigated the expression of the three-RNR classes (Ia, Ib and III) during Escherichia coli biofilm formation. We show the temporal and spatial importance of class Ib and III RNRs during this process in two different E. coli wild-type strains, the commensal MG1655 and the enteropathogenic and virulent E2348/69, the prototype for the enteropathogenic E. coli (EPEC). We have established that class Ib RNR, so far considered cryptic, play and important role during biofilm formation. The implication of this RNR class under the specific growth conditions of biofilm formation is discussed. © 2012 Cendra et al. Source

Discover hidden collaborations