Spatiotemporal patterns of particulate matter (PM) and associations between PM and mortality in Shenzhen, China

DOI: 10.1186/s12889-016-2725-6Background: Most studies on air pollution exposure and its associations with human health in China have focused on the heavily polluted industrial areas and/or mega-cities, and studies on cities with comparatively low air pollutant concentrations are still rare. Only a few studies have attempted to analyse particulate matter (PM) for the vibrant economic centre Shenzhen in the Pearl River Delta. So far no systematic investigation of PM spatiotemporal patterns in Shenzhen has been undertaken and the understanding of pollution exposure in urban agglomerations with comparatively low pollution is still limited. Methods: We analyze daily and hourly particulate matter concentrations and all-cause mortality during 2013 in Shenzhen, China. Temporal patterns of PM (PM2.5 and PM10) with aerodynamic diameters of 2.5 (10) μm or less (or less (including particles with a diameter that equals to 2.5 (10) μm) are studied, along with the ratio of PM2.5 to PM10. Spatial distributions of PM10 and PM2.5 are addressed and associations of PM10 or PM2.5 and all-cause mortality are analyzed. Results: Annual average PM10 and PM2.5 concentrations were 61.3 and 39.6 μg/m3 in 2013. PM2.5 failed to meet the Class 2 annual limit of the National Ambient Air Quality Standard. PM2.5 was the primary air pollutant, with 8.8 % of days having heavy PM2.5 pollution. The daily PM2.5/PM10 ratios were high. Hourly PM2.5 concentrations in the tourist area were lower than downtown throughout the day. PM10 and PM2.5 concentrations were higher in western parts of Shenzhen than in eastern parts. Excess risks in the number of all-cause mortality with a 10 μg/m3 increase of PM were 0.61 % (95 % confidence interval [CI]: 0.50–0.72) for PM10, and 0.69 % (95 % CI: 0.55–0.83) for PM2.5, respectively. The greatest ERs of PM10 and PM2.5 were in 2-day cumulative measures for the all-cause mortality, 2-day lag for females and the young (0–65 years), and L02 for males and the elder (>65 years). PM2.5 had higher risks on all-cause mortality than PM10. Effects of high PM pollution on mortality were stronger in the elder and male. Conclusions: Our findings provide additional relevant information on air quality monitoring and associations of PM and human health, valuable data for further scientific research in Shenzhen and for the on-going discourse on improving environmental policie

Heavy Metals in Soil and Crops of an Intensively Farmed Area: A Case Study in Yucheng City, Shandong Province, China

Yucheng City is located in northwestern Shandong Province, China, and is situated on the Huang-Huai-Hai Plain, the largest alluvial plain in China. In this study, 86 surface soil samples were collected in Yucheng City and analyzed for cation exchange capacity (CEC), soil organic matter (SOM), pH, available phosphorus (avail. P), phosphorus (P), aluminum (Al), and iron (Fe). These soils were also analyzed for ‘total’ chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb), together with 92 wheat samples and 37 corn samples. There was no obvious heavy metal contamination in the soil and irrigation water. But the long-term accumulation of heavy metals in soil has lead to an increase of Ni, As, Hg and Pb concentrations in some of wheat and corn samples and Cd in wheat samples. Because of the numerous sources of soil heavy metals and the lower level of heavy metal in irrigation water, there is no significant relation between soil heavy metal concentrations and irrigation water concentrations. Cr, Ni were mainly from the indigenous clay minerals according to multivariate analysis. Little contribution to soil heavy metal contents from agricultural fertilizer use was found and the local anomalies of As, Cd, Hg, Pb in wheat and corn grain are attributed to the interactive effects of irrigation and fertilizer used. Aerial Hg, however may also be the source of Hg for soil, wheat and corn

Cash transfers and multiplier effect: lessons from the grain subsidy program in China

This study examines the multiplier effects of the grain subsidy program in China, which is a large food self-sufficiency project that is implemented as a cash transfer program. Income multiplier effects have not been examined in the evaluation of the grain subsidy program although increasing the income of farmers is the original goal of this project. A large number of household-level observations are employed to measure the program’s income multiplier. Results show that the grain subsidy program has an unrealized high income multiplier, and the income promotion effect of the transferred subsidies is from agricultural production derived by intensifying various input uses for each unit of land. The multiplier effect can be particularly utilized by households with good education and poor farmers in less developed regions. Hence, to maximize the income multiplier effect, the grain subsidy distribution method should consider these criteria instead of retaining the prevalent standard that is based on contracted land areas

Cash Transfers and Multiplier Effect: Lessons from the Grain Subsidy Program in China

This study examines the multiplier effects of the grain subsidy program in China, which is a large food self-sufficiency project that is implemented as a cash transfer program. Income multiplier effects have not been examined in the evaluation of the grain subsidy program although increasing the income of farmers is the original goal of this project. A large number of household-level observations are employed to measure the program’s income multiplier. Results show that the grain subsidy program has an unrealized high income multiplier, and the income promotion effect of the transferred subsidies is from agricultural production derived by intensifying various input uses for each unit of land. The multiplier effect can be particularly utilized by households with good education and poor farmers in less developed regions. Hence, to maximize the income multiplier effect, the grain subsidy distribution method should consider these criteria instead of retaining the prevalent standard that is based on contracted land areas

Depression-related brain connectivity analyzed by EEG event-related phase synchrony measure

This study is to examine changes of functional connectivity in patients with depressive disorder using synchronous brain activity. Event-related potentials were acquired during a visual oddball task in 14 patients with depressive disorder and 19 healthy controls. Electroencephalogram recordings were analyzed using event-related phase coherence to obtain the functional network. Alteration of the phase synchronization index (PSI) of the functional network was investigated. Patients with depression showed a decreased number of significant electrode pairs in delta phase synchronization, and an increased number of significant electrode pairs in theta, alpha, and beta phase synchronization, compared with controls. Patients with depression showed lower target-dependent PSI increment in the frontal-parietal/temporal/occipital electrode pairs in delta-phase synchronization than healthy participants. However, patients with depression showed higher target-dependent PSI increments in theta band in the prefrontal/frontal and frontal-temporal electrode pairs, higher PSI increments in alpha band in the prefrontal pairs, and higher increments of beta PSI in the central and right frontal-parietal pairs than controls. It implied that the decrease in delta PSI activity in major depression may indicate impairment of the connection between the frontal and parietal/temporal/occipital regions. The increase in theta, alpha, and beta PSI in the frontal/prefrontal sites may reflect the compensatory mechanism to maintain normal cognitive performance. These findings may provide a foundation for a new approach to assess the effectiveness of therapeutic strategies for depression

Recent Advances in Precision Diamond Wire Sawing Monocrystalline Silicon

Due to the brittleness of silicon, the use of a diamond wire to cut silicon wafers is a critical stage in solar cell manufacturing. In order to improve the production yield of the cutting process, it is necessary to have a thorough understanding of the phenomena relating to the cutting parameters. This research reviews and summarizes the technology for the precision machining of monocrystalline silicon using diamond wire sawing (DWS). Firstly, mathematical models, molecular dynamics (MD), the finite element method (FEM), and other methods used for studying the principle of DWS are compared. Secondly, the equipment used for DWS is reviewed, the influences of the direction and magnitude of the cutting force on the material removal rate (MRR) are analyzed, and the improvement of silicon wafer surface quality through optimizing process parameters is summarized. Thirdly, the principles and processing performances of three assisted machining methods, namely ultrasonic vibration-assisted DWS (UV-DWS), electrical discharge vibration-assisted DWS (ED-DWS), and electrochemical-assisted DWS (EC-DWS), are reviewed separately. Finally, the prospects for the precision machining of monocrystalline silicon using DWS are provided, highlighting its significant potential for future development and improvement

The spatial characteristics of ambient particulate matter and daily mortality in the urban area of Beijing, China

Few epidemiological studies have reported the spatial characteristics of the association between particulate matter <10 mu m in aerodynamic diameter (PM10) and mortality in China. This study explored the spatial characteristics of the association between ambient PM10 and mortality in the urban area of Beijing, China. We collected daily data on air pollution, weather conditions and mortality in the eight urban districts of Beijing from Jan. 1st 2008 to Dec. 31st 2009. A Poisson Generalized Additive Model (GAM) was used to examine the district-specific effects of PM10 on cause-specific mortality. A Poisson Generalized Additive Mixed Model (GAMM) was used to examine the urban-wide association between PM10 and cause-specific mortality while controlling for the random effects of districts, compared with GAM which did not control for the random effects of districts. The inter-quartile ranges (IQRs) of annual PM10 ranged from 83.5 mu g/m(3) (Chaoyang district) to 96.0 mu g/m(3) (Shijingshan district). A 96.0 mu g/m(3) increase of PM10 was associated with a 7.52% (95%CI: 1.78%-13.56%) increase of cardiovascular mortality in Shijingshan district while an 87.0 mu g/m(3) increase of PM10 was associated with a 7.68% (95%CI: 0.08%-15.86%) increase of respiratory deaths in Dongcheng district. The urban-wide effects derived from GAMM showed that an 88.0 mu g/m(3) increase of PM10 was associated with an increase of 1.30% (95%CI: 0.45%-2.16%), 2.60% (95%CI: 0.14%-5.11%) in non-accidental and respiratory mortality, illustrating, higher results than those from the GAM. In conclusion, there is spatial variation in ambient PM10 concentration as well as in the effects of PM10 on cause-specific mortality in the urban area of Beijing. Additionally, GAMM model may be more effective in estimating the spatial association between urban-wide PM10 and cause-specific mortality. (c) 2012 Elsevier B.V. All rights reserved.Environmental SciencesSCI(E)EIPubMed10ARTICLE14-2043

Crystal structure of the catalytic domain of protein-tyrosine phosphatase SHP-1

The crystal structures of the protein-tyrosine phosphatase SHP-1 catalytic domain and the complex it forms with the substrate analogue tungstate have been determined and refined to crystallographic R values of 0.209 at 2.5 A resolution and 0.207 at 2.8 A resolution, respectively. Despite low sequence similarity, the catalytic domain of SHP-1 shows high similarity in secondary and tertiary structures with other protein-tyrosine phosphatases (PTPs). In contrast to the conformational changes observed in the crystal structures of PTP1B and Yersinia PTP, the WPD loop (Trp419-Pro428) in the catalytic domain of SHP-1 moves away from the substrate binding pocket after binding the tungstate ion. Sequence alignment and structural analysis suggest that the residues in the WPD loop, especially the amino acid following Asp421, are critical for the movement of WPD loop on binding substrates and the specific activity of protein-tyrosine phosphatases. Our mutagenesis and kinetic measurements have supported this hypothesis