Effect of line defects on the electrical transport properties of monolayer MoS2_{2} sheet

We present a computational study on the impact of line defects on the electronic properties of monolayer MoS2. Four different kinds of line defects with Mo and S as the bridging atoms, consistent with recent theoretical and experimental observations are considered herein. We employ the density functional tight-binding (DFTB) method with a Slater-Koster type DFTB-CP2K basis set for evaluating the material properties of perfect and the various defective MoS2 sheets. The transmission spectra is computed with a DFTB-Non-Equilibrium Greens Function (NEGF) formalism. We also perform a detailed analysis of the carrier transmission pathways under a small bias and investigate the phase shifts in the transmission eigenstates of the defective MoS2 sheets. Our simulations show a 2-4 folds decrease in carrier conductance of MoS2 sheets in the presence of line defects as compared to that for the perfect sheet

ARBEKACIN – A RAY OF HOPE TO FIGHT AGAINST MDR AND XDR GRAM-NEGATIVE BACTERIA IN A SCIENTIFIC AND COST-EFFECTIVE WAY IN INDIAN SCENARIO

Objective: The objective of the study was to see the in vitro activity of arbekacin, a novel aminoglycoside, against multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacilli (GNB) so that it can become a good alternative as empirical treatment for severe sepsis. Methods: Identification and antibiotic sensitivity testing of the GNB isolated from the clinical samples were done using the VITEK-II system in a tertiary care hospital, Kolkata. MDR and XDR strains were selected by their definitions and molecular characterization was done by multiplex polymerase chain reaction. The minimum inhibitory concentration (MIC) value of arbekacin was detected by the E-test strip and compared with other aminoglycosides. Results: A total of 140 drug-resistant strains including ESBL- and carbapenemase-producing GNB were selected for the study. Arbekacin showed reduced values of MIC50 and MIC90 compared to other aminoglycosides for most of the drug-resistant GNB. Conclusion: Hence, in this drug-resistant era, arbekacin with the advantage of a single daily dose can be used as an empirical choice in severe sepsis as monotherapy or in combination with other antibiotics such as colistin or polymyxin to fight against MDR and XDR bugs

TpPred: A Tool for Hierarchical Prediction of Transport Proteins Using Cluster of Neural Networks and Sequence Derived Features

A top–down predictor, called TpPred, is developed which consists of 3 level of hierarchical classification using cascade of neural networks from sequence derived features. The 1st layer of the prediction engine is for identifying a query protein as transport protein or not; the 2nd layer for the main functional class; and the 3rd layer for the sub-functional class. The overall success rates for all the three layers are higher than 65% that were obtained through rigorous cross-validation tests on the very stringent benchmark datasets in which none of the proteins has 30% sequence identity with any other in the same class or subclass. TpPred achieved good prediction accuracies and could nicely complement experimental approaches for identification of transport proteins. TpPred is freely available to be use in-house as a standalone version and is accessible at http://www.juit.ac.in/attachments/tppred/Home.html

Primary Metabolism of Chickpea Is the Initial Target of Wound Inducing Early Sensed Fusarium oxysporum f. sp. ciceri Race I

BACKGROUND: Biotrophic interaction between host and pathogen induces generation of reactive oxygen species that leads to programmed cell death of the host tissue specifically encompassing the site of infection conferring resistance to the host. However, in the present study, biotrophic relationship between Fusarium oxysporum and chickpea provided some novel insights into the classical concepts of defense signaling and disease perception where ROS (reactive oxygen species) generation followed by hypersensitive responses determined the magnitude of susceptibility or resistant potentiality of the host. METHODOLOGY/PRINCIPAL FINDINGS: Microscopic observations detected wound mediated in planta pathogenic establishment and its gradual progression within the host vascular tissue. cDNA-AFLP showed differential expression of many defense responsive elements. Real time expression profiling also validated the early recognition of the wound inducing pathogen by the host. The interplay between fungus and host activated changes in primary metabolism, which generated defense signals in the form of sugar molecules for combating pathogenic encounter. CONCLUSIONS/SIGNIFICANCE: The present study showed the limitations of hypersensitive response mediated resistance, especially when foreign encounters involved the food production as well as the translocation machinery of the host. It was also predicted from the obtained results that hypersensitivity and active species generation failed to impart host defense in compatible interaction between chickpea and Fusarium. On the contrary, the defense related gene(s) played a critical role in conferring natural resistance to the resistant host. Thus, this study suggests that natural selection is the decisive factor for selecting and segregating out the suitable type of defense mechanism to be undertaken by the host without disturbing its normal metabolism, which could deviate from the known classical defense mechanisms

Gall bladder perforation: A rare complication of a common disease

Perforation of the gall bladder is rare in acalculous cholecystitis, more so following infection with Salmonella typhi. This is a case report of a 55 year old lady who presented with fever for 3 weeks duration with sudden severe generalized pain abdomen associated with bilious vomiting for 2days. The patient was investigated and in view of signs of generalized peritonitis, exploratory laparotomy was done. Operative finding was gallbladder perforation and she underwent cholecystectomy. Post operative period was uneventful and the patient was discharged on 10th post operative day

Spin dependent observable effect for free particles using the arrival time distribution

The mean arrival time of free particles is computed using the quantum probability current. This is uniquely determined in the non-relativistic limit of Dirac equation, although the Schroedinger probability current has an inherent non-uniqueness. Since the Dirac probability current involves a spin-dependent term, an arrival time distribution based on the probability current shows an observable spin-dependent effect, even for free particles. This arises essentially from relativistic quantum dynamics, but persists even in the non-relativistic regime.Comment: 5 Latex pages, 2.eps figures; discussions sharpened and references added; accepted for publication in Physical Review

Arsenic Contamination in Groundwater: A Global Perspective with Emphasis on the Asian Scenario

The incidence of high concentrations of arsenic in drinking-water has emerged as a major public-health problem. With newer-affected sites discovered during the last decade, a significant change has been observed in the global scenario of arsenic contamination, especially in Asian countries. This communication presents an overview of the current scenario of arsenic contamination in countries across the globe with an emphasis on Asia. Along with the present situation in severely-affected countries in Asia, such as Bangladesh, India, and China, recent instances from Pakistan, Myanmar, Afghanistan, Cambodia, etc. are presented

An Eight-year Study Report on Arsenic Contamination in Groundwater and Health Effects in Eruani Village, Bangladesh and an Approach for Its Mitigation

Based on several surveys during 1997-2005 and visits of a medical team to Eruani village, Laksham upazila, Comilla district, Bangladesh, the arsenic contamination situation and consequent clinical manifestations of arsenicosis among the villagers, including dermatology, neuropathy, and obstetric outcome, are reported here. Analysis of biological samples from patients and non-patients showed high body burden of arsenic. Even after eight years of known exposure, village children were still drinking arsenic-contaminated water, and many of them had arsenical skin lesions. There were social problems due to the symptoms of arsenicosis. The last survey established that there is a lack of proper awareness among villagers about different aspects of arsenic toxicity. The viability of different options of safe water, such as dugwells, deep tubewells, rainwater harvesting, and surface water with watershed management in the village, was studied. Finally, based on 19 years of field experience, it was felt that, for any successful mitigation programme, emphasis should be given to creating awareness among villagers about the arsenic problem, role of arsenic-free water, better nutrition from local fruits and vegetables, and, above all, active participation of women along with others in the struggle against the arsenic menace