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101.
102.
Polyhydroxyalkanoates (PHAs) are biodegradable polymers produced by microbes to overcome environmental stress. Commercial
production of PHAs is limited by the high cost of production compared to conventional plastics. Another hindrance is the brittle
nature and low strength of polyhydroxybutyrate (PHB), the most widely studied PHA. The needs are to produce PHAs, which have
better elastomeric properties suitable for biomedical applications, preferably from inexpensive renewable sources to reduce
cost. Certain unique properties of Bacillus subtilis such as lack of the toxic lipo-polysaccharides, expression of self-lysing genes on completion of PHA biosynthetic process
– for easy and timely recovery, usage of biowastes as feed enable it to compete as potential candidate for commercial production
of PHA. 相似文献
103.
Sheran HW Law Rudolf SS Wu Patrick KS Ng Richard MK Yu Richard YC Kong 《BMC molecular biology》2006,7(1):15-13
Background
Hypoxia-inducible factors (HIFs) are involved in adaptive and survival responses to hypoxic stress in mammals. In fish, very little is known about the functions of HIFs. 相似文献104.
In most eukaryotes, telomeres are composed of tandem arrays of species-specific DNA repeats ending with a G-rich 3′ overhang. In budding yeast, Cdc13 binds this overhang and recruits Ten1–Stn1 and the telomerase protein Est1 to protect (cap) and elongate the telomeres, respectively. To dissect and study the various pathways employed to cap and maintain the telomere end, we engineered telomerase to incorporate Tetrahymena telomeric repeats (G4T2) onto the telomeres of the budding yeast Kluyveromyces lactis. These heterologous repeats caused telomere–telomere fusions, cell cycle arrest at G2/M, and severely reduced viability—the hallmarks of telomere uncapping. Fusing Cdc13 or Est1 to universal minicircle sequence binding protein (UMSBP), a small protein that binds the single-stranded G4T2 repeats, rescued the cell viability and restored telomere capping, but not telomerase-mediated telomere maintenance. Surprisingly, Cdc13–UMSBP-mediated telomere capping was dependent on the homologous recombination factor Rad52, while Est1–UMSBP was not. Thus, our results distinguish between two, redundant, telomere capping pathways. 相似文献
105.
106.
Justin R. Garcia Shawn D. Lamm Hai-Chao Han 《Biomechanics and modeling in mechanobiology》2013,12(5):915-927
Arteries are often subjected to torsion due to body movement and surgical procedures. While it is essential that arteries remain stable and patent under twisting loads, the stability of arteries under torsion is poorly understood. The goal of this work was to experimentally investigate the buckling behavior of arteries under torsion and to determine the critical buckling torque, the critical buckling twist angle, and the buckling shape. Porcine common carotid arteries were slowly twisted in vitro until buckling occurred while subjected to a constant axial stretch ratio (1.1, 1.3, 1.5 (in vivo level) and 1.7) and lumen pressure (20, 40, 70 and 100 mmHg). Upon buckling, the arteries snapped to form a kink. For a group of six arteries, the axial stretch ratio significantly affected the critical buckling torque (\(p<0.002\)) and the critical buckling twist angle (\(p<0.001\)). Lumen pressure also significantly affected the critical buckling torque (\(p<0.001\)) but had no significant effect on the critical twist angle (\(p=0.067\)). Convex material constants for a Fung strain energy function were determined and fit well with the axial force, lumen pressure, and torque data measured pre-buckling. The material constants are valid for axial stretch ratios, lumen pressures, and rotation angles of 1.3–1.5, 20–100 mmHg, and 0–270\(^\circ \), respectively. The current study elucidates the buckling behavior of arteries under torsion and provides new insight into mechanical instability of blood vessels. 相似文献
107.
Real-time imaging of cellular and subcellular dynamics in vascularized organs requires image resolution and image registration to be simultaneously optimized without perturbing normal physiology. This problem is particularly pronounced in the lung, in which cells may transit at speeds >1 mm s(-1) and in which normal respiration results in large-scale tissue movements that prevent image registration. Here we report video-rate, two-photon imaging of a physiologically intact preparation of the mouse lung that is stabilizing and nondisruptive. Using our method, we obtained evidence for differential trapping of T cells and neutrophils in mouse pulmonary capillaries, and observed neutrophil mobilization and dynamic vascular leak in response to stretch and inflammatory models of lung injury in mice. The system permits physiological measurement of motility rates of >1 mm s(-1), observation of detailed cellular morphology and could be applied in the future to other organs and tissues while maintaining intact physiology. 相似文献
108.
109.
We present an efficient computational architecture designed using supervised machine learning model to predict amyloid fibril
forming protein segments, named AmylPepPred. The proposed prediction model is based on bio-physio-chemical properties of
primary sequences and auto-correlation function of their amino acid indices. AmylPepPred provides a user friendly web interface
for the researchers to easily observe the fibril forming and non-fibril forming hexmers in a given protein sequence. We expect that
this stratagem will be highly encouraging in discovering fibril forming regions in proteins thereby benefit in finding therapeutic
agents that specifically aim these sequences for the inhibition and cure of amyloid illnesses.
Availability
AmylPepPred is available freely for academic use at www.zoommicro.in/amylpeppred 相似文献110.