Molecular Epidemiological Study of Pyrazinamide-Resistance in Clinical Isolates of Mycobacterium tuberculosis from South India

Pyrazinamide (PZA) has been in use for almost 50 years as a first-line drug for short-course chemotherapy against Mycobacterium tuberculosis. In this study, PCR mediated automated DNA sequencing is used to check the prevalence of PZA resistance among treatment failure cases of pulmonary tuberculosis. Out of 50 clinical isolates examined, 39 had mutations in the pncA gene that encodes Pyrazinamidase, an enzyme required to activate PZA. Of these, 31 (79.5%) were localized to three regions of pncA. We found two isolates with hitherto unreported mutation at amino acid 26 (Ala→Gly) of pncA.     

Direct Amide Synthesis from Alcohols and Amines by Phosphine‐Free Ruthenium Catalyst Systems

Amides are synthesized directly from alcohols and amines in high yields using an in situ generated catalyst from easily available ruthenium complexes such as the (p‐cymene)ruthenium dichloride dimer, [Ru(p‐cymeme)Cl₂]₂, or the (benzene)ruthenium dichloride dimer, [Ru(benzene)Cl₂]₂, an N‐heterocyclic carbene (NHC) ligand, and a nitrogen containing L‐type ligand such as acetonitrile. The phosphine‐free catalyst systems showed improved or comparable activity compared to previous phosphine‐based catalytic systems. The in situ generated catalyst from [Ru(benzene)Cl₂]₂, an NHC ligand, and acetonitrile showed excellent activity toward reactions with cyclic secondary amines such as piperidine and morpholine.     

A novel fast medical image segmentation scheme for anatomical scans

Multimedia Tools and Applications - Medical image is the visual representation of anatomy or physiology of internal structures of the body and it is useful for clinical analysis and medical...     

Helly hypergraph based matching framework using deterministic sampling techniques for spatially improved point feature based image matching

Multimedia Tools and Applications - Hypergraphs are tools for matching of point-features incorporating spatial relationships in the form of hyperedges exhibiting topological and geometric features...     

Standalone PV-fed LED Street Lighting Using Resonant Converter

This paper proposes a single-stage, single-switch, non-isolated step-up converter with resonant inverter for a standalone photovoltaic battery-powered light-emitting diode (LED) street light. The LED driver presented in this paper integrates a high step-up DC–DC converter with coupled inductors and LCC resonant converter into a single-stage conversion circuit topology. The proposed converter is a compact cost-effective driver for powering a 60 W LED Street light with a battery backup charged from PV array of 12 V. The modes of operation and analysis of the proposed converter are explained. The design of the circuit elements is done based on the theoretical analysis. The proposed circuit has been simulated, and prototype has been developed to demonstrate its feasibility.     

Influence of Cr and Y Addition on Microstructure,Mechanical Properties,and Corrosion Resistance of SPSed Fe-Based Alloys

Metallurgical and Materials Transactions A - Present work investigates the microstructural stability during spark plasma sintering (SPS) of Fe-Cr-Y alloys, its mechanical properties and corrosion...     

Acceptorless and Base‐Free Dehydrogenation of Alcohols and Amines using Ruthenium‐Hydride Complexes

An efficient, operatively simple, acceptorless, and base‐free dehydrogenation of secondary alcohols and nitrogen‐containing heterocyclic compounds was achieved by using readily available ruthenium hydride complexes as precatalysts. The complex RuH₂(CO)(PPh₃)₃ ( 1 ) and Shvo’s complex ( 2 ) showed excellent activities for the dehydrogenation of secondary alcohols and nitrogen containing heterocycles. In addition to complexes 1 and 2 , the complex RuH₂(PPh₃)₄ ( 3 ) also showed moderate to excellent activity for the acceptorless dehydrogenation of nitrogen‐containing heterocyclic compounds. Kinetic studies on the oxidation reaction of 1‐phenylethanol using complex 1 were carried out in the presence and the absence of external triphenylphosphine (PPh₃). External addition of PPh₃ had a negative influence on the rate of the reaction, which suggested that dissociation of PPh₃ occurred during the course of the reaction. Hydrogen was evolved from the oxidation reaction of 1‐phenylethanol by using 1 mol% of 1 (88%) and 2 (92%), which demonstrated the possible usage of the catalytic systems in hydrogen generation.     

Catalytic hydrolysis of sodium borohydride by a novel nickel–cobalt–boride catalyst

With the aim of designing an efficient hydrogen generator for portable fuel cell applications nickel–cobalt–boride (Ni–Co–B) catalysts were prepared by a chemical reduction method and their catalytic hydrolysis reaction with alkaline NaBH₄ solution was studied. The performance of the catalysts prepared from NaBH₄ solution with NaOH, and without NaOH show different hydrogen generation kinetics. The rate of hydrogen generation was measured using Ni–Co–B catalyst as a function of the concentrations of NaOH and NaBH₄, as well as the reaction temperature, in the hydrolysis of alkaline NaBH₄ solution. The hydrogen generation rate increases for lower NaOH concentrations in the alkaline NaBH₄ solution and decreases after reaching a maximum at 15 wt.% of NaOH. The hydrogen generation rate is found to be constant with respect to the concentration of NaBH₄ in the alkaline NaBH₄ solution. The activation energy for hydrogen generation is found to be 62 kJ mol⁻¹, which is comparable with that of hydrogen generation by a ruthenium catalyst.