Search results for " Sulfur"
showing 6 items of 56 documents
Succinate dehydrogenase functioning by a reverse redox loop mechanism and fumarate reductase in sulphate-reducing bacteria.
2006
Sulphate- or sulphur-reducing bacteria with known or draft genome sequences (Desulfovibrio vulgaris, Desulfovibrio desulfuricans G20, Desulfobacterium autotrophicum [draft], Desulfotalea psychrophila and Geobacter sulfurreducens) all contain sdhCAB or frdCAB gene clusters encoding succinate : quinone oxidoreductases. frdD or sdhD genes are missing. The presence and function of succinate dehydrogenase versus fumarate reductase was studied. Desulfovibrio desulfuricans (strain Essex 6) grew by fumarate respiration or by fumarate disproportionation, and contained fumarate reductase activity. Desulfovibrio vulgaris lacked fumarate respiration and contained succinate dehydrogenase activity. Succi…
Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆
2013
Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…
Cyclic Sulfoximine and Sulfonimidamide Derivatives by Copper‐Catalyzed Cross‐Coupling Reactions with Elemental Sulfur
2023
Copper-catalyzed cross-coupling reactions of α-bromoaryl NH-sulfoximines with elemental sulfur lead to benzo[d][1,3,2]dithiazole-1-oxides, which represent a new class of three-dimensional heterocycles. The reactions proceed under mild conditions showing good functional group and heterocycle tolerance. By imination/oxidation, the initial cross-coupling products can be converted to unprecedented cyclic sulfonimidamides derivatives. Furthermore, a seven-membered heterocycle was obtained by a ruthenium-catalyzed ring-expansion with ethyl propiolate. peerReviewed
Caracterización de barita cubana y su reducción carbotérmica en horno de microondas
2007
The Cuban Barite (BaSO<sub>4</sub>) is characterized by X ray diffraction, chemical analysis and scanning electron microscopy. The principal components are identified and its characteristic morphology is shown. Its carbothermic reduction under microwave irradiation is carried out with the purpose of to improve the yield of this stage during the mineral transformation process in reagent of barium of diverse applications.<br><br>La barita cubana (BaSO<sub>4</sub>) se ha caracterizado por difracción de rayos X, análisis químico y microscopía electrónica de barrido. Se han identificado sus componentes mayoritarios y así mismo se muestra su morfología caracter…
Effect of low SO2 postharvest treatment on quality parameters of ‘Italia’ table grape during prolonged cold storage
2018
Table grape is a non-climacteric fruit with a low rate of physiological activity, very sensitive to water loss and fungal infection (Botrytis cinerea) during postharvest handling and cold storage. Gray mold is the most aggressive postharvest disease, because of its ability to develop at low temperatures, for that reason, it is standard practice to fumigate with sulfur dioxide (SO2) immediately after packing. ‘Italia’ table grape boxes were stored at 2°C for 4 months in a storage room with low concentrations of SO2 (0.20%) to extend their postharvest shelf life. Every 15 days, a sample of ‘Italia’ table grapes boxes was moved to 20°C for 3 days for the shelf life simulation. During storage, …
L-cysteine and glutathione metabolism are impaired in premature infants due to cystathionase deficiency.
1995
There are conflicting reports in the literature as to whether L-cysteine is an essential amino acid in premature infants as the result of the absence of hepatic cystathionase activity. To analyze the physiological importance of the cystathionase deficiency, we studied sulfur amino acid metabolism in human neonates of different gestational ages. Plasma cystathionine concentrations are higher in premature infants < or = 32 wk gestation (group 1) than in premature infants of 33-36 wk gestational age (group 2) or in full-term infants (group 3), whereas plasma cysteine concentrations are much lower in group 1 and 2 premature infants than in mature infants. Furthermore, erythrocytes from group 1 …