[Risk assessment and analysis of polycyclic aromatic hydrocarbons in the surface sediments of Xinglin Bay Suburb Rivers of Xiamen].

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), declared as carcinogens by USEPA, were measured in the sediment samples (n = 19) collected along Xinglin Bay rivers/canals present in Xiamen. PAHs were extracted using accelerated solvent extraction system and analyzed using gas chromatography-mass spectrometry (GC-MS). The possible sources of PAHs and their health risk were investigated. Among selected PAHs, 13 PAHs were detected in the surface sediments. Total concentrations of PAHs in the surface sediments ranged from 413.00 to 2748.81 ng x g(-1), with a mean value of 949.56 ng x g(-1). The mean concentration of highly carcinogenic compounds such as benzo [k] fluoranthene (BkF) and benzo [g, h, i] perylene (BghiP) were 69.15 ng x g(-1) and 49.86 ng x g(-1), respectively and counted for 73.68% out of the total samples. The dominant PAH compounds were 2, 3 and 4 rings and counted for 61.03% and 23.53% , respectively; while 5-6 rings containing PAHs were accounted for 15.82%. According to the results, 68.42% of samples were moderately contaminated, while 31.58% were highly contaminated with PAHs. Based on the ratios of Ant/(Ant + Phe) and Fla/(Fla + Pyr), it cleared that PAHs in surface sediments were mainly derived from fossil fuel and combustion products. Principal component analysis results and sediment quality benchmarks (mSQG-Q) were used for risk assessment of these PAH contaminated sediments. The risk SQG-Q of 16 PAHs were less than 0.50. Comprehensive content, composition and SQG-Q showed that a certain degree of ecological risks of PAH pollution existed in the surface sediments, particularly in the sites close to Xinglin Industrial Zone (2, 3, 5 and 9) and Gangtou(13), which need further research work and proper attentions.

Risk factors for post-ERCP pancreatitis: a systematic review of clinical trials with a large sample size in the past 10 years.

BACKGROUND: Post- endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is the most common and most severe complication associated with diagnostic and therapeutic ERCP. A multivariate analysis of risk factors for PEP is essential for identifying patients at high risk and subsequently choosing other suitable diagnoses. METHODS: Pertinent publications were identified through systematic searches of MEDLINE, Elsevier, and Springer; we performed a systematic review of 12 clinical studies published in the past ten years, selected out of 451 reviewed articles, in which risk factors for pancreatitis were identified. Seven probable risk factors were evaluated, and outcomes expressed in the case of dichotomous variables, as an odds ratio (OR) (with a 95% confidence interval, 95% CI). RESULTS: When the risk factors were analyzed, the OR for female gender was 1.40 (95% CI 1.24 to 1.58); the OR for previous PEP was 3.23 (95% CI 2.48 to 4.22); the OR for previous pancreatitis was 2.00 (95% CI 1.72 to 2.33); the OR for endoscopic sphincterotomy was 1.42 (95% CI 1.14 to 1.78); the OR for precut sphincterotomy was 2.11 (95% CI 1.72 to 2.59); the OR for Sphincter of Oddi dysfunction was 4.37 (95% CI 3.75 to 5.09); and the OR for non-prophylactic pancreatic duct stent was 2.10 (95% CI 1.63 to 2.69). CONCLUSIONS: It appears that female gender, previous PEP, previous pancreatitis, endoscopic sphincterotomy, precut sphincterotomy, Sphincter of Oddi dysfunction, and non-prophylactic pancreatic duct stent are the risk factors for post-ERCP pancreatitis.

Shape-dependent localized surface plasmon enhanced UV-emission from ZnO grown by atomic layer deposition.

Two-dimensional arrays of Al nanoparticles (NPs) were used to demonstrate the localized surface plasmon resonance (LSPR) enhanced UV light emission from ZnO grown by atomic layer deposition. Well defined NP arrays with different shapes were fabricated on the surface of ZnO by electron-beam lithography. A theoretical analysis based on the finite-difference time-domain method was carried out to show the shape dependence of the LSPR wavelength. Time resolved photoluminescence and temperature-dependent photoluminescence measurements suggested that the Al NPs arrays increase the radiative recombination rate by the resonance coupling between the localized surface plasmons and the excitons of the ZnO. By top excitation of the Al NP arrays coupled with ZnO, a 2.6-fold enhancement in peak photoluminescence intensity was measured. The enhancement strongly depended on the NP's shape, revealing an important way of geometrical tuning the UV-emission.