BACKGROUND Genetic polymorphisms of metabolizing enzymes may affect the risk of cancer formation in humans. Since the diet can contain polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs), the relationship between polymorphisms of enzymes involved in PAH and HA metabolism and the occurrence of sporadic colorectal cancer was studied. PATIENTS AND METHODS Five hundred colorecta...

Combined high-resolution fluorescence detection X-ray absorption near-edge spectroscopy, X-ray diffraction, and X-ray emission spectroscopy have been employed under operando conditions to obtain detailed new insight into the nature of the Mo species on zeolite ZSM-5 during methane dehydroaromatization. The results show that isolated Mo-oxo species present after calcination are converted by CH4 ...

Singlet state structures of small, cyclic hydrocarbons which can result from the addition of molecular dicarbon (C2) to ethyne (HC≡CH) or ethene (H2C=CH2) have been calculated (B3LYP/6311+G(d,p) level of theory), and were found to contain carbene centres. Some structures of analogous boranes (replacement of the carbene centers by BH fragments) were also calculated. The computation of NMR parame...

The problem of soot emissions from diesel engines is introduced and the possible solution of combining doped perovskites and microwave (mw) irradiation to "clean up" diesel soot filters is outlined. Eighteen doped perovskite catalysts are synthesized and tested for propane and CO oxidation, which are taken as model components for soot. The activity, selectivity, and SO2 tolerance are compared u...

The oxygen-free conversion of methane on transition-metal catalysts could be an interesting alternative to the oxygen-containing conversion (OCM) due to its higher selectivity towards higher hydrocarbons (C2+). So far, the main obstacle has been the low conversion rate compared to the OCM process. This is mostly ascribed to the fact that oxygen-free CH4-conversion is accompanied by a quick depo...

Multi-year time series records of C2-C6 alkanes, C2-C4 alkenes, ethyne, isoprene, C6-C8 aromatics, trichloroethene (C2HCl3), and tetrachloroethene (C2Cl4) from canister samples collected during January 2004– February 2008 at the University of New Hampshire (UNH) AIRMAP Observatory at Thompson Farm (TF) in Durham, NH are presented. The objectives of this work are to identify the sources of nonme...

The effect of activation environment (N2, H2 and H2S/H2) on the hydrocracking performance a NiMo/Al catalyst was studied at 380 °C 3.5 MPa using octacosane (C28). physical structure acidity were characterized by BET, XRD, SEM-EDX FTIR techniques. N2 generated more active nonsulfided relative to or H2S (XC28, 70–80% versus 6–10%). For comparison, NiMo/Si-Al also tested after normal showed higher...