A high temporal-spatial vehicle emission inventory based on detailed hourly traffic data in a medium-sized city of China.

To improve the accuracy and temporal-spatial resolution for a vehicle emission inventory in a medium-sized city with a strip road network, this study was conducted based on detailed hourly traffic-flow data for each day of 2014, and covered all road types and regions in the city of Foshan. Detailed hourly emission characteristics and sources in five regions were analysed. The results showed that the total vehicle emissions of CO, NOX, VOCs, and PM2.5 were 13.10 × 104, 0.23 × 104, 4.46 × 104, and 0.18 × 104 tons, respectively. Motorcycles (MCs) and light passenger cars (LPCs) were the dominant contributors of CO emissions, while buses and heavy passenger cars (HPCs) were the dominant contributors for NOX. As a whole, the daytime contributions to total emissions were close to 80%, and emissions during the peak periods accounted for almost 40%. Specifically, the hourly emissions of each pollutant on workdays were higher than on non-workdays (maximum up to 64.2%), and for some roads the early peak periods changed significantly from workdays to non-workdays. At expressways, artery roads, and local roads, the daily emission intensities of CO, NOx, and PM2.5 in Foshan were close to or even higher than that of Beijing. On a regional scale, the temporal variation of vehicle emissions on workdays at artery roads of different regions were similar. In addition, the higher emission intensities of CO and VOCs were identified in DaLiang-RongGui (DLRG) and that of NOX and PM2.5 were in Central Region (CR). These results are meaningful for decision-makers to help provide more detailed vehicle pollution control measures in Foshan with a strip road network and only one ring road.

Intestinal perforation secondary to ingested foreign bodies: a single-center experience with 38 cases.

OBJECTIVE: The aim of this study is to report our experience with patients with intestinal perforation secondary to ingested foreign bodies (FBs) who were treated surgically at our institution. METHODS: Between 2001 and 2015, a total of 38 pediatric patients with the diagnosis of intestinal perforation secondary to FBs were retrospectively reviewed. RESULTS: The series comprised 22 males and 16 females. The average age of the patients was 1.9 years. A definitive preoperative history of the ingestion of FBs was obtained for only eight patients. Crying and abdominal pain were the main clinical manifestations. Perforation repair was performed in 29 patients (76.3%), while enterostomy was utilized in five patients (13.2%) and enterectomy in four patients (10.5%). Five perforations occurred in the large intestine, and 33 perforations occurred in the small intestine with the most common site being the distal ileum. Of the 38 FBs recovered, 26 were food objects, while non-food objects were found in 12 patients. All patients recovered well, except one patient with an intestinal obstruction from adhesions that occurred approximately 1 month after discharge. CONCLUSIONS: Clinical performance of intestinal perforation secondary to FBs in children is atypical. Most perforations occur in the small intestine. Primary perforation repair is safe and effective, and better outcomes can be achieved.

Assessment of Co-benefits of vehicle emission reduction measures for 2015-2020 in the Pearl River Delta region, China.

Vehicle emissions have become one of the key factors affecting the urban air quality and climate change in the Pearl River Delta (PRD) region, so it is important to design policies of emission reduction based on quantitative Co-benefits for air pollutants and greenhouse gas (GHG). Emissions of air pollutants and GHG by 2020 was predicted firstly based on the no-control scenario, and five vehicle emissions reduction scenarios were designed in view of the economy, technology and policy, whose emissions reduction were calculated. Then Co-benefits between air pollutants and GHG were quantitatively analyzed by the methods of coordinate system and cross-elasticity. Results show that the emissions reduction effects and the Co-benefits of different measures vary greatly in 2015-2020. If no control scheme was applied, most air pollutants and GHG would increase substantially by 20-64% by 2020, with the exception of CO, VOC and PM2.5. Different control measures had different reduction effects for single air pollutant and GHG. The worst reduction measure was Eliminating Motorcycles with average reducing rate 0.09% for air pollutants and GHG, while the rate from Updated Emission Standard was 41.74%. Eliminating Yellow-label Vehicle scenario had an obvious reduction effect for every single pollutant in the earlier years, but Co-benefits would descent to zero in later by 2020. From the perspective of emission reductions and co-control effect, Updated Emission Standard scenario was best for reducing air pollutants and GHG substantially (tanα=1.43 and Els=1.77).

Efficacy of metformin on pregnancy complications in women with polycystic ovary syndrome: a meta-analysis.

OBJECTIVE: To evaluate the efficacy of metformin administration throughout pregnancy on pregnancy-related complications in women with polycystic ovary syndrome (PCOS). STUDY DESIGN: MEDLINE and ScienceDirect were searched to retrieve relevant trials. The endpoint was the incidence of complications of pregnancy, gestational diabetes mellitus (GDM), pre-eclampsia (PE), miscarriage and premature birth included. RESULTS: Five studies with 502 PCOS patients with metformin administration throughout pregnancy and 427 controls who used metformin just to get conception were included in our meta-analysis. In study group, a significantly lower change of emerging miscarriage and premature birth was observed, the pooled relative risk (RR) was 0.32 (95% confidence interval (CI): 0.19-0.56) for miscarriage and 0.40 (95%CI: 0.18-0.91) for premature birth. No significant difference was demonstrated in emerging GDM and PE. CONCLUSIONS: Metformin therapy throughout pregnancy can reduce the RR of miscarriage and premature birth incidence in PCOS patients with no serious side effects.

[Speciation and bioavailability of heavy metals in paddy soil irrigated by acid mine drainage].

Based on field investigation and laboratory analysis, the speciation and bioavailability of the heavy metals (Cd, Cu, Pb, and Zn) was studied. These metals were tested from 16 soil samples taken from paddy soils irrigated by acid mine drainage in the lower stream of Dabaoshan mine area, Guangdong Province, China. The toxicity characteristic leaching procedure (TCLP) and three-step community bureau of reference (BCR) sequential extraction procedure methods were used to analyse the bioavailability of heavy metals. TCLP is currently recognized as an international method for evaluation of heavy metal pollution in soils. Two methods were compared in bioavailability by stepwise multiple linear regression analysis. Cd was dominated mainly by the acid-extractable and residual fractions, and followed by the order of acid-extractable > residual > oxidisable > reducible. Cu was dominated mainly by the residual fraction, and decreased in the following order: residual > reducible > acid-extractable > oxidisable. Pb was dominantly released in the reducible and residual fractions, they account for 86.54% of the total contents, and decreased in the following order: reducible > residual > acid-extractable > oxidisable. Zn was dominated mainly by the residual fraction, it takes more than 50% of the total contents, and followed by the order of residual > acid-extractable > reducible > oxidisable. The levels of Cd, Cu, Pb and Zn extracted by TCLP were 0.17-0.89, 8.12-70.33, 3.16-90.33 and 10.24-106.85 mg x kg(-1), respectively, and the average concentrations of Cd, Cu, Pb and Zn were 0.41, 36.60, 15.97 and 50.78 mg x kg(-1), respectively. The concentrations of Cd, Cu, Ph and Zn in rice seeds were 0.183-0.947, 3.542-5.997, 0.285-1.532 and 17.54-41.10 mg x kg(-1), respectively. Comparing to the national standards on heavy metals in foods by the Chinese Ministry of Health, the contents of Cu and Zn in rice seeds didn't exceed the upper limit, while the contents of Cd and Pb in rice seeds exceed the upper limit by 87.50% and 81.25%, respectively. Results of the stepwise multiple linear regression analysis revealed that contents of Cd and Zn in seeds of rice were significantly influenced by contents of acid-extractable Cd and Zn, that contents of Cu in seeds of rice were significantly influenced by contents of acid-extractable and oxidisable Cu, and the contents of Pb in seeds of rice were significantly influenced by contents of reducible Pb and organic matter. Contents of four metals in seeds of rice were significantly influenced by contents of metals extracted by TCLP, and the influences of total content, pH and organic matter were not significant. In short, TCLP method was fast, simple and suitable for evaluation of bioavailability of heavy metals in sewage-irrigated paddy soils by acid mine drainage.