The metal/oxide/n-silicon tunneling diodes with hydrogen (deuterium) passivated Si/SiO2 interface are stressed under hole-injection conditions to investigate the mechanism of gate oxide degradation. Although the isotope effect on soft breakdown was previously observed in the deuterium-annealed metal/oxide/p-silicon devices, no isotope effect on the oxide soft breakdown was observed in the metal...

The determination of natural mass independent isotope variations by precise isotopic measurements of elements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) requires a detailed understanding of the instrumental mass bias. Until recently, the instrumental mass bias in MC-ICP-MS analysis was considered to be entirely mass dependent, most often corrected by an exponent...

The planar oxygen isotope effect coefficient measured as a function of hole doping in the Prand La-doped YBa2Cu3O7 (YBCO) and the Ni-doped La1.85Sr0.15CuO4 (LSCO) superconductors quantitatively and qualitatively follows the form originally proposed by Kresin andWolf [Phys. Rev. B 49, 3652 (1994)], which was derived for polarons perpendicular to the superconducting planes. Interestingly, the inv...

effects on chemical shift of hydrogen bonded compounds in solution. For recent more complete reviews see [7, 8, 25] and for isotope effects primarily on intermolecular hydrogen bonding and in the solid state the papers by the Limbach group [3, 4, 33, 34]. The paper will concentrate on intrinsic isotope effects and not so much on equilibrium ones. The review will also concentrate on situations w...

Isotope effect may cause partial chromatographic separation of labeled (heavy) and unlabeled (light) isotopologue pairs. Together with a simultaneous matrix effect, this could lead to unacceptable accuracy in quantitative liquid chromatography-mass spectrometry assays, especially when electrospray ionization is used. Four biologically relevant reactive aldehydes (acrolein, malondialdehyde, 4-hy...

DFT calculations for methyl cation complexed within a constrained cage of water molecules permit the controlled manipulation of the "axial" donor/acceptor distance and the "equatorial" distance to hydrogen-bond acceptors. The kinetic isotope effect k(CH3)/k(CT3) for methyl transfer within a cage with a short axial distance becomes less inverse for shorter equatorial C⋅⋅⋅O distances: a decrease ...

Stable isotope ratios of hydrogen and oxygen in microbes have been shown to be functions of the corresponding isotope ratios of the water with which the culture medium was prepared, and thus to contain a potential geographic signal. Water can evaporate from agar (solid) media during culturing, changing its isotope ratios. Here we describe the effect of drying on the isotope ratios of water extr...

In order to study the initial as well as the final steps in the aromatization of androgens to estrogens, highspecific activity [ 19-CSHs]androstenedione and testosterone were synthesized. Incubations of [ 19-CSHs]androstenedione with human placental microsomes resulted in the generation of [‘Hlwater, as a result of the dual hydroxylation at (2-19, and [’Hlformic acid reflecting final aromatizat...

Hydrogen atom transfer reactions between the substrate and coenzyme are key mechanistic features of all adenosylcobalamin-dependent enzymes. For one of these enzymes, glutamate mutase, we have investigated whether hydrogen tunneling makes a significant contribution to the mechanism by examining the temperature dependence of the deuterium kinetic isotope effect associated with the transfer of a ...