The influence of low temperature on soybean (Glycine max [L.] Merr. cv. Wells) energy transduction via mitochondrial respiration and dehydrogenases was investigated in this study during imbibition and germination. Mitochondria were isolated from embryonic axes of seeds treated at 10 and 23 C (control) by submergence in H(2)O for 6 hours and maintenance for an additional 42 hours in a moist envi...

Rate coefficients are reported for the gas-phase reaction of the hydroxyl radical (OH) with C2Cl4 (k1) over an extended temperature range at 740 ( 10 Torr in a He bath gas. These absolute rate measurements were conducted using a laser photolysis/laser-induced fluorescence (LP/LIF) technique under slow flow conditions. The lower temperature values for k1 are within (2σ of previous data using dif...

The structural similarity between the primary molecules of voltage-gated Na and K channels (alpha subunits) and activation gating in the Hodgkin-Huxley model is brought into full agreement by increasing the model's sodium kinetics to fourth order (m(3) → m(4)). Both structures then virtually imply activation gating by four independent subprocesses acting in parallel. The kinetics coalesce in fo...

Characteristics of 3-hydroxy-3-methylglutaryl-CoA reductase from normal liver, Morris hepatomas 5123C, 5123t.c. and 9618A, and host liver were studied. Animals were fed on control and 5%-cholesterol diets. Microsomal membranes from all tissues were found to accumulate cholesterol after 3 days on the 5%-cholesterol diet. The enzyme of the tumours showed no feedback inhibition by dietary choleste...

Abstraction of hydrogen atoms by pthalimide-N-oxyl radicals is an important step in the N-hydroxyphthalimide catalyzed autoxidation of hydrocarbons. In this contribution, the temperature dependency of this reaction is evaluated by a detailed transition state theory based kinetic analysis for the case of toluene. Tunneling was found to play a very important role, enhancing the rate constant by a...

Large negative thermal quenching (NTQ) of the yellow luminescence (YL) for a temperature increase from 5 to 300 K is observed in non-polar InGaN/GaN quantum well (QW) samples due migration carriers InGaN QW layers GaN barrier first time. Such an unusual phenomenon happens only when are optically excited inside layers, providing solid evidence occurrence transfer photoexcited layers. A simple mo...

Arrhenius plots of fluoride- and guanine-nucleotide-stimulated adenylate cyclase activity were linear in adipocyte plasma membranes from lean and obese (ob/ob) mice. Arrhenius plots of isoprenaline-stimulated adenylate cyclase activity in hepatic plasma membranes biphasic in both groups. The results were biphasic in membranes from lean mice but linear in membranes from obese mice. In contrast, ...

Penicillin G acylase catalysed the hydrolysis of 4-nitrophenyl acetate with a kcat of 0.8 s-1 and a Km of 10 microM at pH 7.5 and 20 degreesC. Results from stopped-flow experiments fitted a dissociation constant of 0.16 mM for the Michaelis complex, formation of an acetyl enzyme with a rate constant of 32 s-1 and a subsequent deacylation step with a rate constant of 0.81 s-1. Non-linear Van't H...

this paper addresses the annealing temperature effect on nanostructure and phase transition of copper oxide thin films, deposited by pvd method on glass substrate (at 110 nm thickness) and post annealed at different temperatures (200-400°c) with a flow of 1 cm3s-1 oxygen. the x-ray diffraction (xrd) was employed for crystallographic and phase analyses, while atomic force microscopy (afm) was us...