We present the detection of deuterated molecular hydrogen (HD) in the remote Universe in a damped Lyman-α cloud at z abs = 2.418 toward the quasar SDSS J143912.04+111740.5. This is a unique system in which H 2 and CO molecules are also detected. The chemical enrichment of this gas derived from Zn ii and S ii is as high as in the Sun. We measure N(HD)/2N(H 2) = 1.5 +0.6 −0.4 × 10 −5 , which is s...

Enantiomerically pure (R,R)-(+)-2,3-diphenylpiperazine with 98% ee was obtained by resolution of the corresponding racemic mixture using (1S)-(+)-10-camphorsulfonic acid. The partially resolved enriched sample of (S,S)-(–)-2,3-diphenylpiperazine with 73% ee was purified to obtain samples of 97% ee using different achiral acids via the preparation of either homochiral or heterochiral hydrogen bo...

Estimates of the deuterium abundance in quasar absorbers are reviewed, including a brief account of incorrect claims published by the author and a brief review of the problem of hydrogen contamination. It is concluded that the primordial abundance may be universal with a value (D/H)P ≈ 10 , within about a factor of two, corresponding to ΩBh 2 0.7 ≈ 0.02 or η10 ≈ 2.7 in the Standard Big Bang. Th...

Metal-rich (CB, CH, Isheyevo) carbonaceous chondrites are characterized by the highest whole-rock enrichments in 15 N (δ 15 N up to +1500‰) and nearly complete absence of interchondrule fine-grained matrix [e.g., 1]. The fine-grained material occurs mainly as chondritic clasts, which experienced low-temperature aqueous alteration on their initial parent body(ies) and were subsequently accreted ...

The enrichment of Fe, relative to alpha-elements such as O and Mg, represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how Fe II emission in quasars is linked to physical conditions and abundance, we have constructed a 830-level Fe II model atom and investigated through photoionization calculations how Fe II emission strengths depend on ...

For more than one century, hydrogen assisted degradation of metallic microstructures has been identified as origin for severe technical component failures but the mechanisms behind have not yet been completely understood so far. Any in-situ observation of hydrogen transport phenomena in microstructures will provide more details for further elucidation of these degradation mechanisms. A novel ex...

We investigated the mechanisms leading to rapid death of corals when exposed to runoff and resuspended sediments, postulating that the killing was microbially mediated. Microsensor measurements were conducted in mesocosm experiments and in naturally accumulated sediment on corals. In organic-rich, but not in organic-poor sediment, pH and oxygen started to decrease as soon as the sediment accumu...

Dietary enrichment with docosahexaenoic acid (DHA) has numerous beneficial effects on health. However, the intake of high doses of polyunsaturated fatty acids can promote lipid peroxidation and the subsequent propagation of oxygen radicals. The purpose of this study was to evaluate the effect of DHA on lipid peroxidation and tight junction structure and permeability in Caco-2 cell cultures. Mor...

Recent advances in constructing stellar evolution models of hydrogen-deficient post-asymptotic giant branch (AGB) stars are presented. Hydrogen-deficiency can originate from mixing and subsequent convective burning of protons in the deeper layers during a thermal pulse on the post-AGB (VLTP). Dredge-up alone may also be responsible for hydrogendeficiency of post-AGB stars. Models of the last th...