Association of single nucleotide polymorphisms (SNPs) with gastric cancer susceptibility and prognosis in population in Wuwei, Gansu, China.

BACKGROUND: Gastric cancer (GC) is the sixth most common cancer. China is one of the most frequent GC occurred countries, and Wuwei, Gansu, is one of the highest incidence area in China. Possible biomarkers of GC susceptibility and prognosis among the population in Wuwei are urgently needed. METHODS: All participants in this study were recruited from the Wuwei Cancer Hospital in Gansu, including 303 patients diagnosed with GC and 200 non-cancer controls. DNA was extracted for further single nucleotide polymorphisms (SNP) genotyping. All SNPs were firstly screened by additive logistic regression model then selected SNPs were subjected to univariate Cox regression analysis and multivariate Cox regression analysis for their associations with GC occurrence. RESULTS: The results showed that 31 SNPs were significantly related to the incidence of GC in Wuwei, Gansu, China. Genotype rs4823921 was significantly related to the overall survival of GC patients and AC/AA genotype of rs4823921 polymorphism was significantly associated with an increased risk of GC in Wuwei population. CONCLUSIONS: Thirty-one SNPs were significantly related to the incidence of GC in Wuwei and rs4823921 genotype AC/AA was significantly associated with poor prognosis of GC patients in Wuwei, Gansu.

Mechanism of ultraviolet bonding of perfluoropolyethers revisited.

The mechanism of ultraviolet (UV) bonding of perfluoropolyether (PFPE) boundary lubricants on magnetic disk surfaces is re-examined experimentally. It is found that UV-emitted photoelectrons may contribute a negligible part, and instead the UV bonding correlates with the direct photodissociation of PFPE molecules. The UV-induced photodissociation is demonstrated to occur almost randomly on the PFPE molecular chain. The contribution from photooxidation is eliminated under nitrogen purge.

Real-time observation of surface reactivity and mobility with scanning tunneling microscopy.

Scanning tunneling microscopy allows the direct observation of reactions on surfaces on the atomic scale that otherwise must be inferred from the statistical behavior of hundred of trillions of molecules or atoms. Since the study of the details of reactions on this length scale began, our conception of surface reactivity has changed profoundly. In this Account we focus attention on our real-time observations of reactions for a number of systems, including the island growth of surface oxide on Cu(110), the anisotropic and site-specific reactivity of this oxide with carbon monoxide and ammonia, the collective motion of laterally interacting O(a) and SO(3)(a), and the incorporation of metal atoms into the structures of molecular intermediates formed in the reaction of ammonia with O(a) on Ag(110). These nanoscale, time-resolved movies capture the events as they occur, providing a dynamic picture of the distribution of reactants and products on the surface, thus providing a better understanding of the roles of reactant distribution and site specificity in surface reactivity.