Biophysical Parameters
Mostrando 25-36 de 40 artigos, teses e dissertações.
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25. Biophysical optima for metabolism of Mycobacterium leprae.
The metabolic response of freshly harvested, nude-mouse-derived Mycobacterium leprae to biophysical parameters was studied to facilitate an understanding of axenic culture requirements. Quantitation of intracellular ATP and the rate of [U-14C]palmitic acid incorporation into phenolic glycolipid I (PGL-I) were used as metabolic indicators after axenic incubat
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26. Cellular Biophysics During Freezing of Rat and Mouse Sperm Predicts Post-thaw Motility1
Though cryopreservation of mouse sperm yields good survival and motility after thawing, cryopreservation of rat sperm remains a challenge. This study was designed to evaluate the biophysics (membrane permeability) of rat in comparison to mouse to better understand the cooling rate response that contributes to cryopreservation success or failure in these two
Society for the Study of Reproduction.
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27. Spike Inference from Calcium Imaging Using Sequential Monte Carlo Methods
As recent advances in calcium sensing technologies facilitate simultaneously imaging action potentials in neuronal populations, complementary analytical tools must also be developed to maximize the utility of this experimental paradigm. Although the observations here are fluorescence movies, the signals of interest—spike trains and/or time varying intracel
The Biophysical Society.
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28. Biophysical Parameters Influence Actin-based Movement, Trajectory, and Initiation in a Cell-free System
Using a biochemically complex cytoplasmic extract to reconstitute actin-based motility of Listeria monocytogenes and polystyrene beads coated with the bacterial protein ActA, we have systematically varied a series of biophysical parameters and examined their effects on initiation of motility, particle speed, speed variability, and path trajectory. Bead size
The American Society for Cell Biology.
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29. Analysis of the Dynamic and Steady-State Responses of Growth Rate and Turgor Pressure to Changes in Cell Parameters 1
The physical analysis of plant cell enlargment is extended to show the dependence of turgor pressure and growth rate under steady-state conditions on the parameters which govern cell wall extension and water transport in growing cells and tissues, and to show the dynamic responses of turgor and growth rate to instantaneous changes in one of these parameters.
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30. Monitoring Biophysical Properties of Lipid Membranes by Environment-Sensitive Fluorescent Probes
We review the main trends in the development of fluorescence probes to obtain information about the structure, dynamics, and interactions in biomembranes. These probes are efficient for studying the microscopic analogs of viscosity, polarity, and hydration, as well as the molecular order, environment relaxation, and electrostatic potentials at the sites of t
The Biophysical Society.
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31. Template-dependent, in vitro replication of rotavirus RNA.
A template-dependent, in vitro rotavirus RNA replication system was established. The system initiated and synthesized full-length double-stranded RNAs on rotavirus positive-sense template RNAs. Native rotavirus mRNAs or in vitro transcripts, with bona fide 3' and 5' termini, derived from rotavirus cDNAs functioned as templates. Replicase activity was associa
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32. RNA dynamics in live Escherichia coli cells
We describe a method for tracking RNA molecules in Escherichia coli that is sensitive to single copies of mRNA, and, using the method, we find that individual molecules can be followed for many hours in living cells. We observe distinct characteristic dynamics of RNA molecules, all consistent with the known life history of RNA in prokaryotes: localized motio
National Academy of Sciences.
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33. Patterned library analysis: A method for the quantitative assessment of hypotheses concerning the determinants of protein structure
Site-directed mutagenesis and combinatorial libraries are powerful tools for providing information about the relationship between protein sequence and structure. Here we report two extensions that expand the utility of combinatorial mutagenesis for the quantitative assessment of hypotheses about the determinants of protein structure. First, we show that resi
The National Academy of Sciences.
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34. A model of dendritic spine Ca2+ concentration exploring possible bases for a sliding synaptic modification threshold.
We used a biophysical model of an isolated dendritic spine to assess quantitatively the impact of changes in spine geometry, Ca2+ buffer concentration, and channel kinetics on Ca2+ dynamics following high-frequency activation of N-methyl-D-aspartate receptors. We found that varying the buffer concentration in the postsynaptic density from 50 to 500 microM ca
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35. Huntington's disease age-of-onset linked to polyglutamine aggregation nucleation
In Huntington's Disease and related expanded CAG repeat diseases, a polyglutamine [poly(Gln)] sequence containing 36 repeats in the corresponding disease protein is benign, whereas a sequence with only 2–3 additional glutamines is associated with disease risk. Above this threshold range, longer repeat lengths are associated with earlier ages-of-onset. To i
The National Academy of Sciences.
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36. The Biophysics of Leaf Growth in Salt-Stressed Barley. A Study at the Cell Level1
Biophysical parameters potentially involved in growth regulation were studied at the single-cell level in the third leaf of barley (Hordeum vulgare) after exposure to various degrees of NaCl stress for 3 to 5 d. Gradients of elongation growth were measured, and turgor pressure, osmolality, and water potentials (ψ) were determined (pressure probe and picolit
American Society of Plant Physiologists.