Various mechanisms of the formation of naphthalene and its substituted derivatives have been investigated by ab initio G3(MP2,CC)∕B3LYP∕6-311G∗∗ calculations of potential energy surfaces for the reactions of one and two C(2)H additions to styrene combined with RRKM calculations of product branching ratios under single-collision conditions. The results show that for the C(2)H + styrene reaction,...

It has been postulated that organic-rich planetesimals played a crucial role in the origin of life, but the mechanism by which the organics could have been delivered to a planetary surface is not well understood. We have developed a technique for launching aluminum projectiles at velocities above 11.0 km/s [1]. We fabricated a target that represented both the planet and the bolide. An inorganic...

Fifteen strains of polycyclic aromatic hydrocarbon (PAH)-catabolizing bacteria, identified as Pseudoalteromonas spp. were isolated from Eagle Harbor, Puget Sound, USA, using a most probable number procedure in which naphthalene or phenanthrene was the sole carbon and energy source. Despite having identical 16S rDNA sequences, some catabolized many PAHs, whereas others oxidized only naphthalenes...

MATERIALS AND METHODS: Pluronic F127 fibers, 1.5 mm in diameter, were sacrificed in type I collagen, creating a central looped microchannel. 100μL polyculture cell suspension mixture of 5 x 10 cells/mL of human foreskin fibroblasts and 5 x 10 cells/mL of human aortic smooth muscle cells was seeded into the microchannel. The following day, a 100μL cell suspension of 5 x 10 cells/mL of human plac...

Polycyclic aromatic hydrocarbon (PAH) degrading Sphingomonas sp. strain KS14 was isolated from soil. Strain KS14 was able to utilize phenanthrene and naphthalene as sole source of carbon and energy, and mineralize phenanthrene to carbon dioxide. Strain KS14 cometabolically degraded pyrene using phenanthrene as secondary growth substrate. A large degradative plasmid (>500 kb) was detected from t...

Quantitative analysis by liquid chromatography-mass spectrometry (LC-MS) is frequently based on the application of isotopically labeled standards which usually have to be specially synthesized. Although the synthesis of deuterated isotopologues is relatively inexpensive, they are not considered as good internal standards due to the possible deuterium effect on the retention time during LC-MS an...

A rapid LC-MS/MS method was developed and partially validated for the quantitation of montelukast in spiked sheep plasma. A total run time of 1.5 min was achieved using a short monolithic column and employing a rapid gradient. Sample preparation involved protein precipitation with twofold acetonitrile by volume during which a deuterated internal standard (montelukast D-6) was incorporated. The ...

The Deepwater Horizon (DWH) blowout in the northern Gulf of Mexico represents one of the largest marine oil spills. Significant shifts in bacterial community composition in the water column correlated to the microbial degradation and utilization of oil hydrocarbons. Nevertheless, the full genetic potential and taxon-specific metabolisms of bacterial hydrocarbon degraders enriched during the DWH...

Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaerobic conditions, in a previous study an unusual site was found in San Diego Bay in which two PAHs, naphthalene and phenanthrene, were oxidized to carbon dioxide under sulfate-reducing conditions. Further investigations with these sediments revealed that methylnaphthalene, fluorene, and fluorant...