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601.
Xuefeng Zhao Madhavan L. Raghavan Jia Lu 《Biomechanics and modeling in mechanobiology》2011,10(2):177-189
The traditional approaches of estimating heterogeneous properties in a soft tissue structure using optimization-based inverse
methods often face difficulties because of the large number of unknowns to be simultaneously determined. This article proposes
a new method for identifying the heterogeneous anisotropic nonlinear elastic properties in cerebral aneurysms. In this method,
the local properties are determined directly from the pointwise stress–strain data, thus avoiding the need for simultaneously
optimizing for the property values at all points/regions in the aneurysm. The stress distributions needed for a pointwise
identification are computed using an inverse elastostatic method without invoking the material properties in question. This
paradigm is tested numerically through simulated inflation tests on an image-based cerebral aneurysm sac. The wall tissue
is modeled as an eight-ply laminate whose constitutive behavior is described by an anisotropic hyperelastic strain energy
function containing four parameters. The parameters are assumed to vary continuously in the sac. Deformed configurations generated
from forward finite element analysis are taken as input to inversely establish the parameter distributions. The delineated
and the assigned distributions are in excellent agreement. A forward verification is conducted by comparing the displacement
solutions obtained from the delineated and the assigned material parameters at a different pressure. The deviations in nodal
displacements are found to be within 0.2% in most part of the sac. The study highlights some distinct features of the proposed
method, and demonstrates the feasibility of organ level identification of the distributive anisotropic nonlinear properties
in cerebral aneurysms. 相似文献
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Vaidyanatha Lyer Thankamani Raghavan Nair Giridhar 《Biotechnology and Bioprocess Engineering》2004,9(6):435-439
ThreeBacillus strains were isolated from soil samples. Morphological and physiological characterization indicated that the isolated strains
wereB. mycoides, B. licheniformis andB. brevis. White pepper was produced from black pepper by the fermentative method using the isolates in shake flaks as well as in a
large-scale fermenter. Volatile oil and piperine contents of the product were 3.2% (v/w) and 4% (v/w) respectively. The moisture
content was 15%. The microbial contamination was less than 10 per 100 g. The product also exhibited excellent storage stability. 相似文献
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Vindya K. Gopinatha Ray Ujjayinee Mantelingu Kempegowda Raghavan Sathees C. Rangappa Kanchugarakoppal S. 《Russian Journal of Bioorganic Chemistry》2020,46(5):837-844
Russian Journal of Bioorganic Chemistry - A series of theophylline methyl 1,3,4-oxadiazole small molecules were obtained via cyclization of theophylline-7-acetohydrazide with different benzoic... 相似文献
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Andrographolide is a potent anticancer and anti-inflammatory agent isolated from the plant Andrographis paniculata. It is found to be cytotoxic against various cancer cell lines (in vitro) and also reported to act as an anti-inflammatory agent by interfering with NF-κB protein. Andrographolide induced higher percentage of apoptosis in glutathione-depleted lymphoma cell lines. Andrographolide was also reported to form dehydrated adduct with reduced glutathione at 50° C. On the basis of these observations, the docking analysis of andrographolide with its target protein (NF-κB/p50) and its proposed anti-target protein (glutathione S-transferase) was carried out. Docking analysis predicted the best putative pose of andrographolide molecule in the active site of NF-κB and glutathione S-transferase proteins. Here we report that the furan ring of andrographolide interacts with cysteine 59 of NF-κB/p50 and thereby inhibiting the protein action. Docking studies showed the andrographolide binding to the H-site of glutathione S-transferase enzyme which resembles the behaviour of susceptible xenobiotics inactivated by glutathione S-transferase enzyme. Andrographolide obeys Pfizer's rule but drug-likeness value for andrographolide is found to be negative as the molecule showed low drug score. Hence, inactivation by glutathione S-transferase and low drug score could possibly be the reasons to make andrographolide inactive in clinical trial. 相似文献
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Chetana Baliga Benjamin Selmke Irina Worobiew Peter Borbat Siddhartha P. Sarma Wolfgang E. Trommer Raghavan Varadarajan Nilesh Aghera 《Biophysical journal》2019,116(5):807-817
pH is an important factor that affects the protein structure, stability, and activity. Here, we probe the nature of the low-pH structural form of the homodimeric CcdB (controller of cell death B) protein. Characterization of CcdB protein at pH 4 and 300 K using circular dichroism spectroscopy, 8-anilino-1-naphthalene-sulphonate binding, and Trp solvation studies suggests that it forms a partially unfolded state with a dry core at equilibrium under these conditions. CcdB remains dimeric at pH 4 as shown by multiple techniques, such as size-exclusion chromatography coupled to multiangle light scattering, analytical ultracentrifugation, and electron paramagnetic resonance. Comparative analysis using two-dimensional 15N-1H heteronuclear single-quantum coherence NMR spectra of CcdB at pH 4 and 7 suggests that the pH 4 and native state have similar but nonidentical structures. Hydrogen-exchange-mass-spectrometry studies demonstrate that the pH 4 state has substantial but anisotropic changes in local stability with core regions close to the dimer interface showing lower protection but some other regions showing higher protection relative to pH 7. 相似文献