[Inorganic nitrogen wet deposition in eastern China: Comparison of different land use-based monitoring sites in north and south regions]. / ä¸­å›½ä¸œéƒ¨åœ°åŒºæ— æœºæ°®æ¹¿æ²‰é™: 南-北不同类型监测点的比较.

China is one of the global hotspots of atmospheric nitrogen (N) deposition. This is especially true for eastern China, an economically developed and densely populated area, which emits large quantities of anthropogenic reactive N species to the air and experiences high levels of atmospheric N deposition. Few studies, however, have examined spatial variations of N deposition across different ecosystems in northern and southern regions of eastern China. Using the traditional rain gauge (SDM6A) method, we conducted a three-year (2011-2013) study to quantify wet N deposition fluxes at twelve sites (six northern and six southern monitoring sites, covering urban, rural and background land use types) in China. The annual volume-weighted mean (VWM) concentrations of NH4+-N, NO3--N and total inorganic N (TIN) atmonitoring sites were in the ranges of 0.62-2.76, 0.54-2.50 and 1.25-4.92 mg N·L-1, and averaged 1.4, 1.5 and 2.9 mg N·L-1, respectively. Northern sites showed higher concentrations of N species in precipitation than southern sites. Annual deposition fluxes of NH4+-N, NO3--N and TIN were in the ranges of 7.0-18.3, 6.9-18.9 and 14.9-32.6 kg N·hm-2·a-1, averaging 11.5, 12.2 and 23.7 kg N·hm-2·a-1, respectively. There were significant differences in total N deposition fluxes among different land use types in the north, showing the decreasing order of urban sites (26.3±6.4 kg N·hm-2·a-1)> rural sites (21.8±3.5 kg N·hm-2·a-1)> background (15.5±1.3 kg N·hm-2·a-1). Total N deposition fluxes at urban, rural and background sites in the south were (26.8±2.7), (25.5±2.9) and (20.5±2.4) kg N·hm-2·a-1, respectively, showing no significant spatial variation. While urban sites did not show obvious regional differences, total N wet deposition fluxes at rural and background sites in the south were significantly higher than those at corresponding sites in the north. Our results revealed that both south and north regions of eastern China (including background areas) are receiving high levels of wet N deposition and associated ecological and environmental risks should be considered.

[Epidemiological characteristics on the clustering nature of pandemic (H1N1) 2009 in China].

OBJECTIVE: To study the epidemiological characteristics on the clustering nature of pandemic (H1N1) 2009 in China. METHODS: Time and place distribution of pandemic (H1N1) 2009 on the nature of clustering through data from Public Health Emergency Management Information System were described. RESULTS: As of August 10, 2010, 2773 pandemic (H1N1) 2009 clusters, a total of 77 363 cases (including 20 deaths) were reported in the mainland of China. The most reported number of clusters was from schools and kindergartens with the total number of 2498 (accounted for 90.08% of the total number). Middle schools appeared the have the most clusters (1223, accounting for 48.96%). The number of clusters reported in the southern provinces (cities) accounted for 77.03% of the total, and was more than that in the northern provinces (cities). Two reported peaks in the southern provinces (cities) were in June and November, 2009, respectively. There was only one reported peak in the northern provinces in September, 2009. CONCLUSION: Time and place distribution characteristics on the clusters of pandemic (H1N1) 2009 were similar to the seasonal influenza, but the beginning of winter peak was much earlier and intensity of reporting was much higher on the clusters of pandemic (H1N1) 2009 than that of seasonal influenza.

[Survey on the epidemic characteristics of suicidal tendency among middle-school students in cities].

OBJECTIVE: To identify the epidemical characteristics of suicidal tendency among middle-school students in cities of China and to explore the main factors leading to suicidal tendency in adolescents. METHODS: Multi-stage cluster sampling method was used to select 9015 students in grades 1, 2, 3 and 4 respectively from 25 general middle schools in Beijing, Hangzhou, Wuhan and Urumqi of China in June 2006 and field investigation was carried out through "China Global School-based Student Health Survey (GSHS) Questionnaire". RESULTS: Among the students in the four cities, the incidence rates of suicidal ideation were from 14.4% to 20.8% with an average of 17.4%. The incidence rates of suicidal plan were from 6.8% to 9.7% with an average of 8.2% and were different among cities. 15.0% of the boys had suicidal ideation and 6.7% of them made a suicidal plan comparing to 19.7% of girls having had suicidal ideation and 9.5% of them made a suicidal plan. The two kinds of suicidal tendency in girls were all higher than those in boys. City, age, gender, grade, days and type of being bullied, depression, close friends and having received health education on coping with stresses were factors influencing suicidal tendency of students. Days of being bullied and suicidal tendency showed a dose-response relation. CONCLUSION: Suicidal tendency seemed common in middle-school students. Training on 'coping the issue' should be strengthened and harmonious environment should be improved in middle-schools.