Search results for "RATES"

Addition of reducing agent dithiothreitol improves 4-decanolide synthesis by the genus Sporidiobolus.

2000

Two species of the genus Sporidiobolus, S. johnsonii and S. ruinenii, were used to study the effect of the reducing agent, dithiothreitol (DTT), on 4-decanolide production using ricinoleic acid as the substrate. The results indicate that the addition of DTT into the cultures significantly enhanced 4-decanolide biosynthesis by the two species.

Experimental evidence for proton motive force-dependent catalysis by the diheme-containing succinate:menaquinone oxidoreductase from the Gram-positiv…

2006

In Gram-positive bacteria and other prokaryotes containing succinate:menaquinone reductases, it has previously been shown that the succinate oxidase and succinate:menaquinone reductase activities are lost when the transmembrane electrochemical proton potential, Deltap, is abolished by the rupture of the bacteria or by the addition of a protonophore. It has been proposed that the endergonic reduction of menaquinone by succinate is driven by the electrochemical proton potential. Opposite sides of the cytoplasmic membrane were envisaged to be separately involved in the binding of protons upon the reduction of menaquinone and their release upon succinate oxidation, with the two reactions linked…

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…

Chitin: A Structural Biopolysaccharide with Multiple Applications

2014

Chitin is a naturally occurring fibre-forming polymer that plays a protective role in many lower eukaryotes similar to that of cellulose in plants. Chemically it is a long-chain unbranched polysaccharide made of N-acetylglucosamine residues linked through β-1,4 covalent bonds; it is the second most abundant organic compound in nature, after cellulose. Taking into account the role played by chitin in different biological structures (i.e. fungal cell walls, insect peritrophic matrix, insect and crustacean cuticles, eggshells from nematodes, cyst wall of protozoa), its metabolism (biosynthesis and degradation) is essential for different morphogenetic events. Absent in vertebrates and plants, c…

Effects of Citric Acid on Human Gingival Epithelium

1987

Über die polymerisation von acrylnitril mit silbernitrat

1963

Die Polymerisation von Acrylnitril mit AgNO3 in Substanz und in Losung wird untersucht. In orientierenden Kinetischen Versuchen wird gefunden, das die Reaktion nach einem radikalischen Mechanismus ablauft; sie wird durch Licht katalysiert. Auserdem wird die Aktivitat einer Reihe anorganischer Salze und organischer Nitratebei der Initiierung der Polymerisation gepruft. Die Reaktionsmoglichkeiten werden diskutiert. The polymerization of acrylonitrile with AgNO3 in bulk and in solution was investigated. Informative kinetic experiments were carried out and it is suggested that a radical mechanism is operative; light acts as a catalyst. A number of inorganic salts and organic nitrates were check…

Effect of nanoaquacitrates on physiological parameters of Fodder Galega infected with phytoplasma

2018

The laboratory experiments have been found that so aking seeds Galega orientalis L. (Fodder galega) in nanoaquacitrates solutions of Mn (10 and 20 mg/dm 3), Mo (4 mg/dm3) and Mg (2 and 4 mg/dm3), has been lead to germination energy rise, while Mn( 10 and 20 mg/dm3) and Mo (4 mg/dm3) concentrations has been influenced germinating ability. At the same time, the soaking seeds in solution of nanoaquacitrates Mn (20 mg/dm3) had the biggest stimulatory effect on the accumulation 7 daily sprouts mass (on 18%). It has been shown that s oaking seeds in nanoparticles Mn and Mo solutions leads to the increase of catalase activities (especially under the influence of manganese) and peroxidase activitie…

Computational and theoretical studies on lattice thermal conductivity and thermal properties of silicon clathrates

2016

The lattice thermal conductivity is usually an intrinsic property in the study of thermoelectricity. In particular, relatively low lattice thermal conductivity is usually a desired feature when higher thermoelectric efficiency is pursued. The mechanisms which lower the lattice thermal conductivity are not known in sufficient detail and deeper understanding about the phenomena is needed and if such understanding is achieved it can be used to design more efficient thermoelectric materials. In this thesis, the lattice thermal conductivity and other thermal properties of several silicon clathrates, which are known to be promising candidates for the thermoelectric applications, are studied by theoreti…

Evidence for a link between the Atlantic Multidecadal Oscillation and annual asthma mortality rates in the US

2019

AbstractAn association between climatic conditions and asthma mortality has been widely assumed. However, it is unclear whether climatic variations have a fingerprint on asthma dynamics over long time intervals. The aim of this study is to detect a possible correlation between climatic indices, namely the Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation, and asthma mortality rates over the period from 1950 to 2015 in the contiguous US. To this aim, an analysis of non-stationary and non-linear signals was performed on time series of US annual asthma mortality rates, AMO and PDO indices to search for characteristic periodicities. Results revealed that asthma death rates evalu…

Zebrafish Fins as a Model System for Skeletal Human Studies

2007

Recent studies on the morphogenesis of the fins ofDanio rerio(zebrafish) during development and regeneration suggest that a number of inductive signals involved in the process are similar to some of those that affect bone and cartilage differentiation in mammals and humans. Akimenko et al. (2002) has shown that bone morphogenetic protein-2b (BMP2b) is involved in the induction of dermal bone differentiation during fin regeneration. Many other groups have also shown that molecules from the transforming growth factor-beta superfamily (TGFβ), including BMP2, are effective in promoting chondrogenesis and osteogenesisin vivoin higher vertebrates, including humans. In the present study, we review…