1,303 research outputs found

    Virtual Screening of Drugs against HIV-1 Protease

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    The life-threatening infections and pandemic spread of Human Immunodeficiency virus-1 (HIV-1), the etiologic agent of AIDS, has promoted an unending scientific effort to understand and control the disease. The resultant understanding of HIV-1 life cycle has defined many different targets for potential drug intervention. HIV protease enzyme responsible for cleaving large polyprotein precursors into biologically active protein products is an important target for the treatment of AIDS. However drug resistance is a persistent problem and new protease inhibitors are needed. Tipranavir, one of the protease inhibitors most recently approved for clinical use has been shown to be potent against viruses harbouring multidrug resistance mutations such as V82A and L90M, but even this drug is shown to lose potency due to certain mutations or mutation patterns. Thus 10 derivatives of the drug Tipranavir, chemically diverse from the initial hit were generated and screened to determine their ability to interact with protease. Further analysis revealed one unique compound with high binding ability from the initial hit and its possibility for new class of protease inhibitors is discussed in this report

    Secreted proteins of normal and myc-ras oncogene transformed rat embryo fibroblasts

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    Quiescent cultures of rat embryo fibroblasts synthesize and secrete several proteins in response to mitogenic stimulation. Two of these proteins have been characterized in this study and the effect of oncogenic transformation on these proteins was monitored. A serum induced 48,000 protein was shown to be related to plasminogen activator inhibitor while another serum-induced protein of Mr 45,000 was found to be an inhibitor of DNA synthesis. Transformation of rat embryo fibroblasts with oncogenesmyc andras resulted in drastic reduction in the level of these proteins. The reduced levels of protease inhibitor may be responsible for the loss of anchorage dependence of the transformed cells. The DNA synthesis inhibitor protein may act as a negative growth regulator and reduced levels of this protein in myc-ras transformed cells may accelerate the proliferation of these cells

    ANTIOXIDANT ACTIVITY OF RHIZOME EXTRACTS OF COLEUS FORSKOHLII BRIQ

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    Objective: The present study was on the analysis of the phytochemical constituents of Coleus forskohlii which was collected from five different areas in Tamil Nadu, where it is grown for commercial purposes.Methods: C. forskohlii tubers were collected from five areas (Thiruvannamalai, Kanchipuram, Kallakuruchi, Salem, and Vandalur) of Tamil Nadu. Dried tubers were extracted with different solvents such as aqueous, ethanol, and acetone (polar) and petroleum and chloroform (non-polar). Extracts were evaluated for total phenol and flavonoid content and antioxidant activity evaluation by 1,1-diphenyl-2-picrylhydrazyl (DPPH) reduction.Results: The highest DPPH radical scavenging activity (87.6%) was observed in ethanol extract of rhizome collected from Thiruvannamalai area. Total phenol and flavonoid contents were found to be, respectively, 38.82±0.22 mg gallic acid equivalents/g and 21.34±0.32 quercetin equivalent/g.Conclusion: The study clearly indicated the antioxidative potential of different extracts of C. forskohlii and this property may be useful in the preparation of drug formulations, health tonics, and cosmetics

    Fatal Case of Diazepam and Paraquat Poisoning – A Case Report

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    Background: A very dangerous activity among youth and young adults is the indiscriminate mixing and sharing of prescription drugs, often in combination with alcohol or other drugs. The effects of these combinations of substances can be fatal.Case Report: A 28 years old adult male with alleged history of diazepam and paraquat poisoning was admitted with complaints of chest discomfort, epigastric pain, vomiting and drowsiness. The patient developed acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS) and expired on the next day. To conclude, diazepam even though considered to be a safer drug, has risk of drug abuse and is fatal when taken in overdose along with other central nervous system depressants. Paraquat is a highly toxic compound widely used as herbicide and ingestion of the drug causes death due to respiratory failure. Conclusion: The present study emphasizes on the proper surveillance of diazepam intake in known psychiatric patients and strict rules must be enforced by the Government on marketing of herbicides and pesticides

    Adaptive filtering of radar images for autofocus applications

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    Autofocus techniques are being designed at the Jet Propulsion Laboratory to automatically choose the filter parameters (i.e., the focus) for the digital synthetic aperture radar correlator; currently, processing relies upon interaction with a human operator who uses his subjective assessment of the quality of the processed SAR data. Algorithms were devised applying image cross-correlation to aid in the choice of filter parameters, but this method also has its drawbacks in that the cross-correlation result may not be readily interpretable. Enhanced performance of the cross-correlation techniques of JPL was hypothesized given that the images to be cross-correlated were first filtered to improve the signal-to-noise ratio for the pair of scenes. The results of experiments are described and images are shown

    Coefficient estimates for bi-univalent Ma-Minda starlike and convex functions

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    Estimates on the initial coefficients are obtained for normalized analytic functions ff in the open unit disk with ff and its inverse g=f1g=f^{-1} satisfying the conditions that zf(z)/f(z)zf'(z)/f(z) and zg(z)/g(z)zg'(z)/g(z) are both subordinate to a starlike univalent function whose range is symmetric with respect to the real axis. Several related classes of functions are also considered, and connections to earlier known results are made

    Artificial neural network modeling of the tensile properties of indigeneously developed 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel

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    The severe and hostile operating conditions of fast breeder reactors demand the development of new austenitic stainless steels that possess higher resistance to void swelling and irradiation embrittlement. This paper discusses the efforts made in the laboratory and industrial scale development of a 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel and the evaluation of tensile properties. Melting and casting were carried out in a vacuum induction furnace and the data on recovery of various alloying elements was obtained for charge calculations. Based on the recovery data and decarburisation behavicur under different vacuum levels, a series of alloys with close chemistry variations were prepared. Heat treatment was optimised for these special steels to control the grain size at required level. The ingots were thermo-mechanically processed and tensile properties were evaluated. This experimental data has been used to train and test an artificial neural network. The input parameters of the neural network are chemical compositions and test temperature while the yield strength, ultimate tensile strength and uniform elongation were obtained as output. A multilayer perceptron (MLP) based feed-forward network with back-propagation learning algorithm has been employed. A very good performance of the developed network is obtained. The model can be used as a guideline for new alloy development

    Atypical spinal tuberculosis dural tuberculoma

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    Abstract Introduction: Extra-osseous, epidural tuberculoma are extra central nervous system. Material and methods: from 21yrsto 64 yrs. All patients had spinal tenderness and bone involvement could not be seen in plain radiographs in all five cases. All patients underwent magnetic resonance imaging and only three had no osseou laminectomy with posterior instrumentation done in all cases and the epidural mass had been sent for histo examination which confirmed the diagnosis. therapy and been followed for minimum 2 years. differential diagnosis in compression myelopathy due to spinal tumor syndrome
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