Effect of pesticides on hydrogen metabolism of Rhodobacter sphaeroides and Rhodopseudomonas palustris

Abstract: The present study reports the effect of 2,4- d , quinalphos, monocrotophos, captan and carbendazim on the hydrogen metabolism (nitrogenase, photoproduction of hydrogen and hydrogenase activities) of two purple non-sulfur bacteria isolated from paddy soils. In general, the pesticides were found to be inhibitory to both nitrogenase and hydrogen photoproduction activities of both the organisms, and their effect on hydrogenase-mediated reactions varied with the pesticides used and the organisms.     

Studies of novel pentacyclic heterocyclic steroids: Part XXI. Total synthesis of racemic benz[3,4]-6-oxaestra-1,3,5(10),8-tetraen-17 beta-ol

1-Oxo-4-oxa-1,2,3,4-tetrahydrophenanthrene is converted into racemic benz[3,4]-6-oxaestra-1,3,5(10),8-tetraen-17 beta-ol in 45% yield.     

Europium doped Sr2YNbO6 double perovskite phosphor for photoluminescence and thermoluminescence properties

A luminescent double perovskite phosphor Sr₂YNbO₆ doped with Eu³⁺ crystallized to the monoclinic phase and was synthesized successfully via a conventional high-temperature combustion method. The formation of the crystal structure, phase purity, and surface morphology were studied using X-ray diffraction patterns and scanning electron microscopy. The characteristic vibrations between the atoms of the functional groups present in phosphor were studied using Fourier transform infrared spectra analysis. The luminescence properties of the prepared phosphors were investigated in terms of photoluminescence (PL) and thermoluminescence (TL). PL excitation spectra exhibited charge transfer bands and the characteristic 4f⁶ transitions of Eu³⁺. A prominent PL emission was obtained for the phosphor doped with 4 mol% Eu³⁺ under the 396 nm excitation wavelength. PL emission quenching was observed for the higher doping concentrations due to a multipole–multipole interaction. A highly intense PL emission arose due to the hypersensitive ⁵D₀–⁷F₂ electric dipole transition of Eu³⁺ that dominated the emission spectra. The thermal stability of the phosphor was examined through temperature-dependent PL. The TL properties of the Sr₂YNbO₆ double perovskites irradiated with a ⁹⁰Sr beta source at different doses were measured. The double perovskite phosphors under study showed a linear dose–response with increasing beta dose, ranging from 1 Gy to 10 Gy. Trapping parameters of the TL glow curves were determined using Chen's peak shape method and computerized glow curve deconvolution (CGCD). CGCD fitting of the TL glow curves revealed that it was consisted of three major peaks and followed second-order kinetics. The estimated activation energies were determined using different methods and were comparable and significant.     

Effect of malathion exposure on some physical parameters of whole body and on tissue cations of teleost,Tilapia mossambica (Peters)

Exposure of fish to a sublethal (2 mg/litre/48h) concentration of malathion showed no significant changes in any of the physical parameters investigated like, body weight and body water content, while the oxygen consumption of the fish showed a consistent increase upto 24 h and later declined to 8% suggesting the reduction of oxidative metabolism at the end of 48 h. The sodium, potassium and calcium ions showed a remarkable decrease in all the tissues of malathion-exposed fish, suggesting the loss of ions from the body of these fish. The results suggested that the regulation of osmotic balance may occur by an effective operation of the salt pump rather than the water pump.     

Surface proteome mining for identification of potential vaccine candidates against Campylobacter jejuni: an in silico approach

Functional & Integrative Genomics - Campylobacter jejuni remains a major cause of human gastroenteritis with estimated annual incidence rate of 450 million infections worldwide. C. jejuni is a...     

Synthesis,Molecular Docking,and In Vitro Antibacterial Activities of Some Novel Aminobenzylnaphthol Derivatives via One-Pot Three-Component Reaction

Russian Journal of Bioorganic Chemistry - This work provides the first example of incorporating the thiazole moiety into the aminobenzylnaphthol i.e. Betti base. A series of novel synthesized Betti...