IDENTIFICATION OF LEAD COMPOUNDS WITH COBRA VENOM DETOXIFICATION ACTIVITY IN ANDROGRAPHIS PANICULATA (BURM. F.) NEES THROUGH IN SILICO METHOD

Objective: To validate the cobra venom detoxification activity in Andrographis paniculata and identification of lead molecules.Methods: The structures of phytochemicals were procured from databases or created by ChemSketch and CORINA. Of the14 cobra venom proteins selected as receptor molecules, the 3D structures of phospholipase A2 and cobrotoxin were retrieved from protein data bank and serine protease, L-amino acid oxidase and acetylcholinesterase were modelled. The structures of remaining nine proteins were retrieved from SWISSMODEL repository. The active sites of the receptor molecules were detected by Q-site Finder and Pocket Finder. Docking was carried out by AutoDock 4.2. To avoid error in lead identification, top ranked five hit molecules obtained in AutoDock were again docked by iGEMDOCK, FireDock and HEX server. The results were analyzed following Dempster-Shafer theory. The molecular property and biological activity of the lead molecules were predicted by molinspiration.Results: Docking results in AutoDock revealed that the plant having phytochemicals for detoxifying all venom proteins but only one potential hit molecule against each of the following proteins viz., cobramin A, cobramin B, long neurotoxin 1, long neurotoxin 2, long neurotoxin 3, long neurotoxin 4 and long neurotoxin 5 and several hit molecules (6-12) were obtained against phospholipase A2, cobrotoxin, cytotoxin 3, acetylcholinesterase, L-aminoacid oxidase, proteolase and serine protease. Therefore, in latter case lead molecules were identified through Dempster-Shafer theory. The theoretical prediction of drug likeliness and bioactivity of the molecules highlighted the plant as the best source of anti-cobra venom drug.Conclusion: The results substantiated its traditional use and further investigation on biological system is essential for evolving novel drug.Keywords: Andrographis paniculata, Cobra, Docking, Venom, Protein, Neurotoxin, Snake bit

Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

CONTEXT: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. OBJECTIVES: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. METHODS: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. RESULTS: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. CONCLUSIONS: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions

Pyrolysis Caused Tail-Off Thrust in a Solid Rocket Motor: A Semi-Empirical Model

Knowledge of tail-off thrust characteristics of solid rocket motors used for an upper stage of satellite launch 'Vehicle is essential for proper sequencing of stage separation. The phenomenon is highly complex and theoretical models accurately describing the tail-off thrust are not available. Only rough estimates can be made through ground testing. A semi-empirical model is derived by the authorsusing the Indian polar satellite launch vehicle (PSL V) flight data and is used for fixing the time of stage separation. The model has been validated using data over an extended duration from another flight ofthe PSL V. The method adopted for modelling is described

Synthesis of dipeptides using polymer bound hydroxamic esters - A comparative study of reactivity

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Topographical nature of the polymer matrix and reactivity of attached functional groups: effect of crosslink density on the efficiency of solid-phase hypochlorite oxidations

A series of crosslinked polystyrene-supported hypohalite reagents with the reagent function in different microenvironments were prepared and their reactivities in oxidation and halogenation reactions on organic substrates were investigated. The reactivity of the hypohalite reagent function was observed to be dependent on the topographical nature of the polymer matrix. The reactivity in these cases depends on the degree of crosslinking which affects the extent of functionalisation and also the mechanical integrity and stability of the polymer support. Hypohalite reagents starting from 1%, 2%, 4% and 20% crosslinked polystyrenes were prepared and used for oxidation and halogenation reactions. The reactivity of the hypohalite function is reduced considerably when the degree of crosslinking is increased. A decrease in the degree of functionalisation is also observed with increase in the degree of crosslinking

Prospects of In-Situ α-Al2O3 as an Inoculant in Aluminum: A Feasibility Study

Copyright © 2017 The Author(s). In-situ α-Al2O3 was successfully synthesized and dispersed in Al alloy using B2O3 and ultrasonication-aided liquid mixing technique. Microstructure analysis identified α-Al2O3 as the most common phase in the composite master alloy, whereas AlB12 was frequently observed and AlB2 was rarely found in the alloy. Grain refinement analysis of selected Al alloys registered a transition of columnar to equiaxial grains of α-Al with the inoculation of the master alloy and ultrasonication treatment. Similarly, an improvement in the mechanical properties of A357 alloy was observed with the combination of inoculation and ultrasonication treatment.The authors wish to acknowledge financial support from the ExoMet Project, which is co-funded by the European Commission in the 7th Framework Programme (Contract FP7-NMP3-LA-2012-280421), by the European Space Agency and by the individual partner organizations

Dark matter annihilation at cosmological redshifts: possible relic signal from annihilation of weakly interacting massive particles

We discuss the possibility to observe the products of dark matter annihilation that was going on in the early Universe. Of all the particles that could be generated by this process we consider only photons, as they are both uncharged and easily detectable. The earlier the Universe was, the higher the dark matter concentration $n$ and the annihilation rate (proportional to $n^2$) were. However, the emission from the very early Universe cannot reach us because of the opacity. The main part of the signal was generated at the moment the Universe had just become transparent for the photons produced by the annihilation. Thus, the dark matter annihilation in the early Universe should have created a sort of relic emission. We obtain its flux and the spectrum. If weakly interacting massive particles (WIMPs) constitute dark matter, it is shown that we may expect an extragalactic gamma-ray signal in the energy range 0.5 - 20 {MeV} with a maximum near 8 {MeV}. We show that an experimentally observed excess in the gamma-ray background at 0.5 - 20 {MeV} could be created by the relic WIMPs annihilation only if the dark matter structures in the universe had appeared before the universe became transparent for the annihilation products ($z \simeq 300$). We discuss in more detail physical conditions whereby this interpretation could be possible.Comment: 8 pages, 3 figure

RT-2 Detection of Quasi-Periodic Pulsations in the 2009 July 5 Solar Hard X-ray Flare

We present the results of an analysis of hard X-ray observations of the C2.7 solar flare detected by the RT-2 Experiment onboard the Coronas - Photon satellite. We detect hard X-ray pulsations at periods of ~12 s and ~15 s. We find a marginal evidence for a decrease in period with time. We have augmented these results using the publicly available data from the RHESSI satellite. We present a spectral analysis and measure the spectral parameters.Comment: 12 pages, 8 figures and 3 tables, accepted for publication in The Astrophysical Journa

Development of New Oxide Based Master Alloys and their Grain Refinement Potency in Aluminium Alloys

In this study, grain refinement efficiency of a new oxide master alloy based on MgAl2O4 was demonstrated in Al alloys. The grain size of the reference alloy was reduced by 50-60% with the addition of the master alloy and introduction of ultrasonic cavitation. While cooling rate has an influence on the grain size reduction, more addition of master alloy was found to be not effective in further reducing the grain size.ExoMet Project, which is co-funded by the European Commission in the 7th Framework Programme (contract FP7-NMP3-LA-2012-280421), by the European Space Agency and by the individual partner organisation