Search

Background It is very difficult to contain persistently high incidence and mortality rates of gastric cancer. Moreover, the age at onset of gastric cancer is becoming earlier. However, there are few studies on the prediction of the age at gastric cancer onset. Objective To investigate the relationship between single nucleotide polymorphisms (SNPs) in mitochondrial displacement loop (D-Loop) and age at gastric cancer onset. Methods A total of 150 patients with confirmed gastric cancer by pathologically examination of biopsy samples taken during gastroscopy were recruited from Department of Gastroenterology, the Fourth Hospital of Hebei Medical University between July 2007 and December 2008. PCR was used to amplify the targeted fragment of peripheral blood mitochondrial DNA, and the mitochondrial D-Loop region was sequenced. Survival curves for patients with different ages of onset of gastric cancer were plotted by the Kaplan-Meier method, and compared by the Log-rank test. Cox regression analysis was used to identify factors associated with age of onset of gastric cancer. Results The age of onset of patients with different degrees of education was statistically significant (P

Black-odor water, which is caused by the excessive accumulation of nitrogen and phosphorus in water, is a significant problem. Immobilized microorganisms are considered to be an effective technical solution, but there are still many key parameters to be determined, such as organic matter dissolution, insufficient stability, and insufficient phosphorus removal capacity, among other problems. In this study, the optimum raw material ratios of immobilized microorganism gel beads were determined by means of a response surface experiment. The optimal ratio of raw materials was 5% polyvinyl alcohol (PVA), 1% sodium alginate (SA), and 6% bacterial powder. In addition, the nitrogen and phosphorus removal performance of the materials was improved by loading inorganic compounds, such as 0.5 wt.% zeolite, 0.5 wt.% iron powder, and 0.2 wt.% activated carbon. Tolerance analysis determined that these gel beads could maintain a good performance in a series of harsh environments, such as during intense agitation, at high temperatures, and at low pH values, etc. The total nitrogen (TN), ammonia nitrogen (NH3-N), and phosphorus (TP) removal efficiencies were 88.9%, 90%, and 95%. [ABSTRACT FROM AUTHOR]