Isotopes isotopic Kinetic

The elevated primary isotope kinetic isotope effect (KIE)... 

Transient Isotopic Kinetic Studies of Methanation. - The Fischer-Tropsch reaction results in the formation of a wide distribution of hydrocarbons containing different numbers of carbon atoms. In contrast, the related reaction of methanation of CO/H2 mixtures involves only one product and is easier to study using isotope transient kinetic techniques. The results of the methanation reaction have a direct relevance to the Fischer-Tropsch reaction and are reviewed below. 

Dehydrogenation of hydrocarbons is a most important industrial process. Rubber production from inorganic matter is one of the related examples to which the isotopic kinetic method has been applied . " C-labelled butane and butene used in this studyhave been obtained according to equation 155. Various labelled 1 1 mixtures of... 

In the GC-MS analysis of isotopic enrichment in leucine, the use of the TBDMS derivative gave [M — 57] ions of sufficient intensity for El to be employed for the measurements, which had previously required the more difficult and less readily available Cl method [74]. El with a modem bench-top system and autoinjector allowed complete stable isotope kinetic studies involving hundreds of samples to be reliably completed within days. 

Bal zhinimaev, B.S., Sadovskaya, E.M., Suknev, A.P. (2009) Transient isotopic kinetics study to investigate reaction mechanisms. Chem. Eng. 154,2-8. 

In recent years the development of studies in this field has been substantially accelerated in connection with the use of new methods of investigation. For example, much new information has been successfully obtained using the method of labelled atoms, especially using the isotopic kinetic method [21]. 

The sequence of the formation of various intermediate products in the oxidation of cyclohexane and other hydrocarbons, as well as the rate of formation and dissociation of the intermediate products, can be determined by the isotopic kinetic method [22]. 

However, niacin does not inhibit the selective uptake of HDL cholesteryl esters into the cells (Kamanna and Kashyap 2008). This combination of elfects could raise HDL concentration, enhancing the ability of HDL to shuttle cholesterol from peripheral tissues to the liver. Apolipoprotein A-I (apoA-I) is the major protein associated with HDL. In HepG2 cells, niacin did not increase transcription or synthesis of apoA-I (Kamanna and Kashyap 2008). However, a stable isotope kinetic study in humans showed increased production of apoA-I following the administration of niacin (Lamon-Fava et al. 2008). 

The role of cholesterol absorption, synthesis and turnover in disease states and under therapeutic conditions has been given new stimulation by the publications of Grundy and Ahrens . These authors described their isotope kinetic and sterol balance technique which enables them to measure the... 

Mazda has developed and commercialized a catalyst with Pt supported on a mixed oxide of Ce02 with Zr or Pr for light-duty diesel engine cars. Isotopic kinetic experiments using 02 revealed that formation of the mixed oxide increases the mobility of lattice oxygen and thereby soot oxidation. 

Barzhinimaev, B., Sadovskaya, E. and Suknev, A. (2010). Transient Isotopic Kinetics Study to Investigate Reaction Mechanisms, Chem. Eng. J., 154, pp. 2-8. 

Of the total amount of cholesterol entering the digestive tract (1.0-1.5 g/day) approximately one-third is derived from the diet and two-thirds from bile. Plant sterols and stanols decrease serum cholesterol concentrations by interfering with cholesterol absorption (Figure 7). Dual-isotope studies have shown that, depending on the experimental set-up, the ingestion of plant stanols reduces cholesterol absorption efficiency by 50-80% (Heinemann etal, 1991 Miettinen and Vanhanen, 1994 Gylling and Miettinen, 1994 Jones et al, 2000). Plant sterols reduce cholesterol absorption by up to 50% when measured by the dualisotope method (Jones et al, 2000), isotope kinetic technique (Lees et al, 1977), or intestinal perfusion (Heinemann et al, 1991). 

Carotenoids circulate in plasma in association with low-density and high-density lipoproteins. The level of /3-carotene reflects its recent intake, but it also is higher when plasma lipoprotein levels are elevated. Beta-carotene is stored at relatively low concentrations in liver and fatty tissues. A prolonged slow rate of postabsorptive conversion to retinol has been observed in volunteers in isotope kinetic studies. 

Z. Naturforsch., 44a, 427 (1989). Semiclassical and Quantum Mechanical Calculations of Isotopic Kinetic Branching Ratios for the Reaction of 0( P) with HD. 

The system of isotope-kinetic equations (30)-(31) is not closed since, along with the variables describing the gas phase composition, they contain the 3 independent variable,, the fraction of in the oxide surface. 

The isotope-kinetic equations (30) - (31) allow the elucidation of the mechanism of surface reactions (adsorption-desorption and other processes) and the estimation of the bond strength of the smface oxygen [48-56] considered to be important parameters in analysis of porous MIEC cathodes performance [9]. 

Equation (30). This allows the estimation of the rate of heteroexchange R by using the integral form of isotope-kinetic equation (30)... 

To estimate the oxygen diffusion coefficient from the results of oxygen isotope exchange experiments for powders, the isothermal isotope exchange curves were fitted using a complete system of isotope-kinetic and diffusion equations (30-34). In modeling, the values of diffusion coefficients (coefficients of diffusion relaxation td = D/h ) and the share of the... 

Limbach H H 1991 Dynamic NMR spectroscopy in the presence of kinetic hydrogen/deuterium isotope effects NMR Basic Principles and Progress vol 23, ed P Diehl, E Fluck, H Gunther, R Kosfeld and J Seelig (Berlin ... 

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