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Thermal Reactivity (thermal + reactivity)
Selected AbstractsVascular Function Measured by Fingertip Thermal Reactivity Is Impaired in Patients With Metabolic Syndrome and Diabetes MellitusJOURNAL OF CLINICAL HYPERTENSION, Issue 11 2009Naser Ahmadi MD Digital thermal monitoring (DTM) of vascular function has already been shown to correlate well with coronary artery calcium (CAC) score and coronary artery disease. To determine its utility in the metabolic syndrome (MS) and diabetes mellitus (DM), 233 asymptomatic patients with DM/MS but without coronary artery disease underwent DTM during and after 5 minutes of supra-systolic arm cuff inflation, as well as CAC. Post-cuff deflation adjusted temperature rebound (aTR) was lower in MS and DM compared with the normal group. The odds ratio of lowest vs upper 2 tertiles of aTR was 2.3 for MS and 3.5 for DM compared with the normal group, independent of age, sex, and risk factors. The area under the receiver operating characteristic curve to predict CAC ,100 was 0.69 for metabolic status (DM/MS), 0.79 for aTR, and 0.87 for both. This study demonstrates that vascular dysfunction measured by DTM is associated with DM/MS and could potentially be used to detect asymptomatic individuals with increased subclinical atherosclerosis. [source] Kinetic and mechanistic study on the thermal reactivity of stabilized phosphorus ylides, part 3: [(Acetyl)(arylcarbamoyl)methylene]triphenylphosphoranes and [(alkoxycarbonyl)(arylcarbamoyl)methylene]triphenylphosphoranes and their thiocarbamoyl analoguesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 1 2007R. Alan Aitken A series of five [(acetyl)(arylcarbabmoyl)methylene]triphenyl-phosphoranes 1a,e and their thiocarbamoyl analogues 2a,e, [(alkoxycarbonyl)(arylcarbamoyl)methylene]triphenylphosphoranes 3a,e and their thiocarbamoyl analogues 4a,e were prepared and fully characterized. All ylides are found under conditions of flash vacuum pyrolysis to fragment giving arylisocyanate or isothiocyanate and acetyl ylides or alkoxy ylides which undergo thermal extrusion of Ph3PO. A kinetic study shows that these reactions are unimolecular and are of first-order nature with no significant substituent effect. The thiocarbamoyl ylides 2 react from 4.6 to 42 times faster than their carbamoyl ylides 1, while the thiocarbamoyl ylides 4 react from 6.6 to 20.9 times faster than their carbamoyl ylides 3. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 39: 6,16, 2007 [source] Synthesis, thermal reactivity, and kinetics of stabilized phosphorus ylides, part 2: [(Arylcarbamoyl)(cyano)methylene]triphenylphosphoranes and their thiocarbamoyl analoguesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 8 2006R. Alan Aitken A series of five cyano(arylcarbamoyl) phosphorus ylides 2 and five cyano(arylthiocarbamoyl) phosphorus ylides 3 are prepared and fully characterized. Pyrolytic reaction products of a representative example of each type obtained by flash vacuum pyrolysis technique show that they undergo thermal extrusion of Ph3PO or Ph3PS. Kinetic study of the gas-phase pyrolysis of each ylide by static method shows that these reactions are unimolecular and first order with no significant substituent effect, but the thiocarbamoyl ylides 3 react 40,65 times more rapidly than their carbamoyl analogues 2. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 496,502, 2006 [source] Esterification of n -butyric acid with n -butyl alcohol and transesterification of (R,,S)-phenylethanol by lipase immobilized on cellulose acetate,TiO2 gel fibreJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 1 2002Yuko Ikeda Abstract Lipase (EC 3.1.1.3) was immobilized on cellulose acetate,TiO2 gel fibre by the sol,gel method. The immobilized lipases were used for esterification of n -butyric acid with n -butyl alcohol and enantioselective acylation of (R, S)-phenylethanol using vinyl acetate as an acyl donor. Compared with native lipase, the activity of the immobilized lipase was stable and relatively unaffected by the water content of the solvent and the substrate concentration. The data indicate that the lipases are immobilized on the fibre surface and that enzyme activity is influenced by bound water. However, the thermal reactivity and enantioselectivity of the immobilized lipase were less than those of native lipase. This may not reflect thermal inactivation of the enzyme but rather significant thermal contraction of the gel fibre by cellulose crystallization, resulting in liberation of bound water and a decrease in the amount of enzyme which is available for the reaction. Copyright © 2001 Society of Chemical Industry [source] | ||||||||||