Search

Taking Lingxin Coal Mine as the research object, the combination of physical experiment and numerical simulation analysis was used to study the mining failure of overlying strata and the development of surrounding rock cracks in goaf. The results show that when the underground coal seam mining is not sufficient, the overburden separation is developed, the connected pore area of the overburden failure accounts for about 20% of the total mining area. When the underground coal seam is fully mined, the overburden failure is severe, the overburden failure cracks are interconnected, and the connected pore area increases significantly.

In mining areas where gangue is used for infill mining, Ordovician limestone karst water is affected by discarded gangue, and the water quality changes significantly. In this study, the effects of gangue on water quality change under different immersion solution conditions were evaluated by Zhai Zhen Coal Mine, Hongqi Coal Mine Ordovician Limestone Karst Water, and Baizhuang Coal Mine. The results showed that the cations in each group of immersion solutions had similar trends, and the Na+ concentration fluctuations were greater in karst water immersion solutions with higher initial sodium ion concentrations, while the fluctuations of calcium and magnesium ions were more obvious in the early stage of immersion, and the fluctuations were gradually slowed down in the later stage. The anions in the immersion solution also have a similar fluctuation trend, but only in the early stage of immersion. By comparing the changes of the three indexes (pH, TDS, and ORP) in the immersion solution, it was found that highly mineralized karst water had a good buffering effect on the changes in the basic water quality index, while the ultrapure water quality index with low salinity had the greatest change. The 100% stacked columnar plot between the main water chemical ion changes shows the relative scale relationship of the water chemical components in the immersion solution at each period, and the water chemical components change significantly in the early immersion period (0–7 d), and then enter the fluctuation changes period, and the ion changes in the fluctuation changes period are mainly Na+ and SO42− ions. This study provides a theoretical basis for exploring the changes of gangue to the quality of karst water in Ordovician limestone and also provides theoretical guidance for the study of groundwater pollution mechanisms in closed coal mines.

In order to explore the potential effects of abandoned coal mines on the water quality of Ordovician limestone aquifers, water-rock interaction simulations were conducted. After the closure of the coal mine, the karst water in the goaf area and the waste gangue had a geochemical reaction, and the above-mentioned water-rock process was simulated by an indoor static immersion experiment to explore the differences in the effect of different types of karst water on the dissolution of gangue. The basic water quality parameters pH, EC (electrical conductance), and ORP (oxidation-reduction potential) showed different trends in karst hydro-immersion solution and ultra-pure hydro-immersion solution; pH and EC had greater fluctuations in two sets of ultrapure hydro-immersion solutions, while ORP fluctuated more widely in three groups of karst hydro-immersion solutions. In addition, gangue minerals dissolved more significantly in bodies of water where limestone was added. The results of chemical component clustering showed that TDS (total dissolved solids) and EC were homopolymerized in each immersion solution, and subsequent correlation analysis showed that TDS and EC clusters were more significantly affected by mineral properties in ultrapure water-immersion solutions, and more affected by dominant ions in karst water-immersion solutions.

The health risks posed by atmospheric brominated flame retardants (BFRs) have been widely studied, but there remains a lack of clarity about exposure differences between clear days and haze days. We sampled the total suspended particle (TSP) and gaseous BFRs on clear days in summer, clear days in winter, and haze days in winter in Harbin, China, to investigate the variations in the concentrations and intakes (dermal and inhalation) in the different weather conditions. The concentrations of atmospheric BFRs were highest on haze days in winter (185 pg/m3), followed by clear days in summer (158 pg/m3), and clear days in winter (79.2 pg/m3), and these concentrations were significantly correlated with the concentrations of TSP. The human intake in the different weather conditions followed the pattern of the BFR concentrations, and the human intake of atmospheric BFRs was dominated by inhalation. A comparison of the BFR levels showed that the human intake of gaseous and particulate BFRs varied in the three weather conditions and that the inhalation intake, but not the dermal intake, was influenced under high concentrations of gaseous BFRs with low molecular weight.

The objective of this study was to explore the differences of five methods for evaluating the PM retention capacity of leaves based on the same experimental materials and leaf area measurement method and to summarize the advantages and disadvantages of each method. In this study, four tree species (

Elimination of the intermediate snail host of Schistosoma is the most effective way to control schistosomiasis and the most important first step is to accurately identify the snail habitats. Due to the substantial resources required for traditional, manual snail-searching in the field, and potential risk of miss-classification of potential snail habitats by remote sensing, more convenient and precise methods are urgently needed. Snail data (N = 15,000) from two types of snail habitats (lake/marshland and hilly areas) in Anhui Province, a typical endemic area for schistosomiasis, were collected together with 36 environmental variables covering the whole province. Twelve different models were built and evaluated with indices, such as area under the curve (AUC), Kappa, percent correctly classified (PCC), sensitivity and specificity. We found the presence-absence models performing better than those based on presence-only. However, those derived from machine-learning, especially the random forest (RF) approach were preferable with all indices above 0.90. Distance to nearest river was found to be the most important variable for the lake/marshlands, while the climatic variables were more important for the hilly endemic areas. The predicted high-risk areas for potential snail habitats of the lake/marshland type exist mainly along the Yangtze River, while those of the hilly type are dispersed in the areas south of the Yangtze River. We provide here the first comprehensive risk profile of potential snail habitats based on precise examinations revealing the true distribution and habitat type, thereby improving efficiency and accuracy of snail control including better allocation of limited health resources., Author summary Schistosomiasis is a parasitic disease caused by parasitic worms of the genus Schistosoma. In China, the sole intermediate snail host is Oncomelania hupensis whose elimination has proved to be the most effective way to interrupt this disease. However, manual snail-searching is labour-intensive, expensive and time-consuming and can lead to inaccurate results. For a better approach, 12 models were employed and compared to characterise the typical snail habitats that vary between the lake/marshlands and the hilly areas. We found that the two types of snail habitats showed notable differences during the modelling process, mainly due to the impact of environmental variables that can form different types of habitats. We further found that habitat characterization contributed to better prediction of areas at risk, and that the precision was high, especially of models based on machine-learning algorithms such as random forest (RF). The highest level of accuracy was achieved by the support vector machine (SVM) approach and artificial neural networks (ANN). Our study provides new insights into accurate prediction of the spatial distribution of potential snail habitats with machine-learning as the preferred approach.

Anhui Province has been one of typical epidemic areas of schistosomiasis in East China as a wide range of large lake and marshland regions provide an ideal environment for growth and reproduction of the intermediate snail host. With the completion of the Yangtze River-Huaihe River Water Transfer Project (YHWTP), launched by the end of 2016, the epidemic areas are expected to expand and controlling schistosomiasis remains a challenge. Based on annual surveillance data at the county level in Anhui for the period 2006-2015, spatial and temporal cluster analyses were conducted to assess the pattern of risk through spatial (Local Moran's I and flexible scan statistic) and space-time scan statistic (Kulldorff). It was found that schistosomiasis sero-prevalence was dramatically reduced and maintained at a low level. Cluster results showed that spatial extent of schistosomiasis contracted, but snail distribution remained geographically stable across the study area. Clusters, both for schistosomiasis and snail presence, were common along the Yangtze River. Considering the effect of the ongoing YHWTP on the potential spread of schistosomiasis, Zongyang County and Anqing, which will be transected by the new water-transfer route, should be given a priority for strengthened surveillance and control. Attention should also be paid to Guichi since it is close to one of the planned inlets of the YHWTP.

To accurately and quantitatively evaluate the mass and particle size distribution of water-soluble and water-insoluble particulate matters (PM) on the surface of tree leaves, which would help to improve the accuracy of quantitative assessment of the retention ability of urban trees to atmospheric particles, we collected leaf samples from three broadleaved tree species [Ginkgo (Ginkgo biloba), Chinese scholar tree (Sophora japonica) and weeping willow (Salix babylonica)] and two conifer species [Chinese pine (Pinus tabuliformis) and China savin (Sabina chinensis)] 14 d after the rain (rainfall15 mm). The PMs retained on leaves were collected by a succeeding procedure of washing + brushing (WC+BC) and ultrasonic cleaning (UC). Then, the extracts at each step were divided into water-soluble and water-insoluble PMs through centrifuge. The mass of water-soluble and water-insoluble particles were dry weighted. Then, the water-soluble and water-insoluble particles were dissolved by anhydrous ethanol and deionized water to measure the particle size distribution. The mass of water-soluble and water-insoluble particles with different particle sizes was calculated. Results showed that the mass (proportion) of water-soluble PMs retained on leaf surfaces of broad-leaved and conifer species were 480.61 (52.3%) and 438.91 (47.7%) mg·m为了精确、定量评估植物叶片表面水溶性和非水溶性颗粒物的质量及粒径分布,进一步提高对城市树木大气颗粒物吸滞能力的定量评估精度,本研究以3种阔叶树种(银杏、国槐、垂柳)和2种针叶树种(油松、圆柏)为研究对象,于雨后14 d(降水量15 mm)采集叶样,依次对其进行泡洗+刷洗(WC+BC)、超声清洗(UC),然后对每个清洗步骤下叶片洗脱液进行离心分离,对上清液与沉淀物进行烘干、称量,测定水溶性和非水溶性颗粒物的质量,采用无水乙醇和去离子水对水溶性和非水溶性颗粒物进行溶解,分别测定其粒径分布,并依此计算叶片表面滞纳不同径级水溶性和非水溶性颗粒物的质量.结果表明: 阔叶和针叶树种叶片表面滞纳水溶性、非水溶性颗粒物质量(比例)分别为480.61(52.3%)、438.91(47.7%)和97.93(12.0%)、715.84 mg·m

To study the pollution characteristics, sources, and transportation process of PM

To study the interannual variations of chemical composition and source apportionment, a field campaign was carried out to collect the PM

In order to explore the characteristics of PM

Under a condition of good air quality (AQI:55-90, PM

There has been no consistent conclusion on whether Sarcoptes mites parasitizing in humans and animals are the same species. To identify Sarcoptes (S.) hominis and S. canis in China, gDNA was extracted from individual mites (five from patients with scabies and five from dogs with mange) for amplification of rDNA ITS2, mtDNA 16S, and cox1 fragment sequences. Then, the sequences obtained were aligned with those from different hosts and geographical locations retrieved from GenBank and sequence analyses were conducted. Phylogenetic trees based on 317-bp mtDNA cox1 showed five distinctive branches (species) of Sarcoptes mites, four for S. hominis (S. hominis Chinese, S. nr. hominis Chinese, S. hominis Australian, and S. hominis Panamanian) and one for S. animal (S. animal). S. animal included mites from nine animal species, with S. canis China, S. canis Australia, and S. canis USA clustering as a subbranch. Further sequence divergence analysis revealed no overlap between intraspecific (≤ 2.6 %) and interspecific (2.6-10.5 %) divergences in 317-bp mtDNA cox1. However, overlap was detected between intra- and interspecific divergences in 311-bp rDNA ITS2 or 275-bp mtDNA 16S when the divergences exceeded 1.0 %, which resulted in failure in identification of Sarcoptes. The results showed that the 317-bp mtDNA cox1 could be used as a DNA barcode for molecular identification of Sarcoptes mites. In addition, geographical isolation was observed between S. hominis Chinese, S. hominis Australian, and S. hominis Panamanian, but not between all S. canis. S. canis and the other S. animal belonged to the same species.

Schistosomiasis japonica, caused by Schistosoma japonicum infection, remains a major public health concern in China, and the geographical distribution of this neglected tropical disease is limited to regions where Oncomelania hupensis, the intermediate host of the causative parasite, is detected. The purpose of this study was to monitor the transmission of S. japonicum in potential risk regions of China during the period from 2008 through 2012. To monitor the transmission, 10 fixed surveillance sites and 30 mobile sentinel sites were selected in 10 counties of four provinces, namely Anhui, Jiangsu, Chongqing and Hubei. There were 8, 9, 6, 2 and 3 cases infected with S. japonicum detected in the 30 mobile sentinel sites during the 5-year study period, while 27 subjects were positive for the antibody-based serum test in the 10 fixed sentinel sites; however, no infection was found. In addition, neither local nor imported livestock were found to be infected. No O. hupensis snails were detected in either the fixed surveillance or the mobile sentinel sites; however, the snail host was found to survive and reproduce at Chaohu Lake, inferring the potential of transmission of the disease. It is suggested that the continuous surveillance of schistosomiasis japonica should be carried out in both the endemic foci and potential risk regions of China, and an active, sensitive system to respond the potential risk of transmission seems justified.

The paper aims at presenting an organizational social responsibility approach for improving mine safety and health in China. Through an in-depth comparative analysis of the regulatory mechanisms for mine safety and health in USA and South Africa, it is found that the successful performance of mine safety and health in USA has been contributed by the triangle of effective law enforcement, advanced technology development and qualified labor training, and the impressive improvement of mine health and safety in South Africa has been attributed to the mechanism of tripartite engagement through the state, mine owners and employees. In view of findings from the US and South Africa experiences, an approach of organizational social responsibility through multi-stakeholders is proposed for China to fundamentally improve its performance of mine safety and health by adopting best practices.

Four types of dust from dormitories, offices, hotels and roads in Beijing were collected and fractionated into 9 fractions, respectively. Totally 36 samples were obtained and analyzed for heavy metals including Cu, Zn, Cr, Pb, Cd and Ni. Particle size distributions of those heavy metals in these four types of dust were investigated and the influencing mechanisms were discussed. Distribution patterns of the same heavy metal in different types of dust showed various characteristics. Also different metals in the same type of dust represented different distribution patterns. Heavy metals in road dust tended to concentrate in finer particles. Two offices from the same building, located in Beijing, China, were selected to study the seasonality of heavy metals in dust. Dust sampling from Office A was conducted at weekly intervals between March 2012 and August 2012, while dust from Office B was sampled fortnightly from March 2012 to December 2012. Generally, levels of all heavy metals remained stable among different seasons, however, Cr and Pb represented more significant fluctuations than other four heavy metals. Based on the geo-accumulation index method, the pollution of Zn, Cu and Pb was more serious in the investigated samples, and dust from offices and hotels were moderately polluted by Zn. According to the risk assessment results, the carcinogenic health risks of the six heavy metals in the four types of dust were negligible.

To investigate the cognitive levels of people from Chaohu area, Anhui Province about the prevention and control knowledge of schistosomiasis before the water transfer project operation, so as to provide the reference for formulating the health education intervention.A schistosomiasis questionnaire survey was conducted among the students, fishermen, boat people and villagers from Chaohu selected by the random cluster sampling from May to October, 2014.A total of 1 140 questionnaires were issued with the actual recovery of 1 096 copies and 1 032 valid questionnaires. The awareness rate of prevention and control knowledge of schistosomiasis was from 11.72% to 71.71%. The highest awareness rate was in the "know schistosomiasis", however the lowest awareness rate was in the "know the intermediate host of schistosomiasis". Catching fish or shrimp in river or lake was the main way of contacting water in production activities (39.05%), and swimming or playing in river or lake was the main way of contacting water in life activities (63.18%). The prevention and control knowledge of schistosomiasis by teaching was at a rate of 41.47% on average, and the main way was anti-schistosomiasis professionals going to countryside to do health education (49.53%). That the feces directly discharged into water accounted for 91.14% in fishman and boatman.It is necessary for people from Chaohu to carry out various forms of health education of schistosomiasis prevention and control before the water transfer project operation.

There exists a high risk of water-inrush in mining activities. Therefore, it is critical to develop a conceptual model of Mine Water-inrush, especially for the underground environment. The general structure of Mine Water-inrush Simulation System consists of core network, the underground monitoring network, and the operational system. Through the application of data processing system, simulation system and the application system, the original data can be processed. The results is then passed to the operators and managers, which require them increase the understanding of factors leading to accidents and consequently take action to improve mining safety. This new water-inrush model captures three characteristics to regard the mine water-inrush: the inrush sources, inrush process, and submerging process. Virtual length has been applied to the model, which is combined with a Traversal Algorithm, can be used to calculate the area of increased influence over time for each process. Based on the collected data from a real mine, the underground excavations and a virtual water-inrush disaster process were simulated, which shows that the system operates reliably.

To explore the expression levels of T cell immunoglobulin and mucin domain protein 3 (Tim-3) on peripheral blood CD4+ T cells and its correlation with liver function damage parameters in advanced schistosomiasis patients.Totally 28 advanced schistosomiasis patients were selected as study subjects, and 20 chronic schistosomiasis patients and 30 healthy persons were selected as controls. The expression levels of Tim-3 on CD4+ T cell were detected by flow cytometry, and the serum IFN-γ and IL-4 levels were detected by ELISA. Hitachi 7600 biochemical analyzer was used to analyze the liver function parameters (ALT, γ-GT and TBIL).There was a significant difference in Tim-3 expression among the three groups (F = 4.578,P0.05). Tim-3 expression level in advanced schistosomiasis patients was (8.33 ± 2.28)%, which was significantly higher than that of the healthy control group (6.57 ± 1.99)% (t = 3.015, P0.01). The Spearman nonparametric correlation analysis showed that the Tim-3 expression level on CD4+ T cells in advanced schistosomiasis patients was positively correlated with the serum ALT(r, = 0.746, P0.01), γ-GT(r, = 0.656, P0.01) and IL-4(r, = 0.672, P0.01) levels, but negatively correlated with the serum IFN-γ levels (r(s) = -0.404, P0.05).The expression of Tim-3 on peripheral CD4' T cells is increased in advanced schistosomiasis patients, which may regulate the function of CD4' T cells and then be involved in the liver damage process of advanced schistosomiasis.

To explore the expression of T cell immunoglobulin and mucin domain protein 3 (Tim-3) on CD56(+) NK cells in peripheral blood and its correlation with liver fibrosis indicators in patients with advanced schistosomiasis.Tim-3 expression on CD6(+) NK cells from 28 patients with advanced schistosomiasis and 30 healthy controls was determined by flow cytometry. The serum levels of IFN-y and IL-4 were detected by enzyme-linked immunosorbent assay (ELISA). Fibroscan analyzer was used for liver stiffness measurement (LSM) to determine the extent of liver fibrosis. Four serological indicators of liver fibrosis, collagen type III N-peptide (PIIP N-P), Laminin (LN), collagen IV (CIV) and hyaluronic acid (HA) were measured by the Automated Chemiluminescence Immunoassay Analyzer.Flow cytometry analysis showed that Tim-3 expression on CD56(+) NK cells in advanced schistosomiasis patients was (62.3±11.4)%, significantly higher than that (52.1±6.5)% (P0.01). In patients with advanced schistosomiasis and the healthy controls, the levels of PIIIP N-P were (86.5±29.5) ng/mL and (22.0±7.8) ng/mL, LN (49.3±21.5) ng/mL and (20.4±6.3) ng/mL, CIV (67.5±22.3) ng/mL and (22.0±3.9) ng/mL, HA (645.9±483.1) ng/mL and (54.7±27.7) ng/mL, respectively. There were significant differences in all these indicators between the two groups (P0.05). The levels of IFN-y were (93.9?20.1) ng/L and (107.7?24.6) ng/L, and those of IL-4 were (46.6±11.8) ng/L and (28.9±8.9) ng/L respectively in patients with advanced schistosomiasis and the healthy controls, both with significant differences (P0.05). Spearman nonparametric correlation analysis showed that Tim-3 expression on CD56(+) NK cells in patients was positively correlated with the levels of LSM, PIIIP N-P, LN, CIV and IL-4 (r=0.528-0.834, P0.01), but negatively with serum IFN-y (r=-0.501, P0.01). No correlation was found with the HA level (r=0.352, P0.05).The expression of Tim-3 on peripheral CD56(+) NK cells increases in patients with advanced schistosomiasis compared with the healthy controls, and it positively correlates with the levels of LSM, PIIIP N-P, LN, CIV and IL-4, four indicators of liver fibrosis.

To study the variation of PM2.5 concentration in scenic recreational plantations and its response to meteorological factors, and to analyze the regulation effect of different stands on PM2.5 concentration, in the summer, autumn and winter of 2013, PM2.5 concentration and relevant meteorological factors in four typical scenic recreational plantations (Pinus armandii--Ginkgo biloba mixed plantation, Populus tomentosa--Fraxinus chinensi mixed plantation, Populus tomentosa pure plantation, multiple-species-layered mixed plantation) were simultaneously monitored, in Beijing Olympic Forest Park (the observation was conducted continuously for 28 days). The results showed that the daily variation of PM2.5 concentration in the four stands didn' t represent a unified pattern at different air pollution levels, but were basically consistent at the same pollution level. When the wind force was 0-2 grade, there was no significant difference among daily average PM2.5 concentrations [the average PM2.5 concentration during the observation period (9:00-15:00) ] in the four stands at each pollution level. Stand PM2.5 concentration was positively correlated to air relative humidity (P0.01), negatively correlated with air temperature (P0.05), but uncorrelated with wind speed. Changed percentage of stand PM2.5 concentration compared to the space varied between -21.4% and 33.2%, and it was negatively correlated with air relative humidity (P0.05), but not correlated with the wind speed and air temperature. The regulation effects of the four stands on PM2.5 concentration included both increasing and decreasing effects, and in this study, the critical value of air relative humidity was 67% when this regulation shifted.

To investigate the status of Cryptosporidium infection in the population in the local area of Anhui Province, and discuss the risk factors of the infection, so as to provide the evidence for the prevention and treatment of cryptosporidiosis.Qianshan County and Lingbi County of Anhui Province were selected as investigation spots, and the oocysts of Cryptosporidium in the feces of the investigation objects and the specific IgG antibody against Cryptosporidium in the serum were checked by using the pathogenic modified acid fast staining method and ELISA, respectively, so as to determine the status of Cryptosporidium infection in these investigation objects. At the same time, the questionnaire surveys were conducted in the investigation objects so as to know about the risk factors of Cryptosporidium infection.A total of 668 people were investigated in the two counties, 635 people received etiological examinations, and 15 people were positive with the positive rate of 2.36%; 642 people received serological examinations, and 140 people were positive with the positive rate of 21.81%; 628 people received pathogenic and serological examinations at the same time, and the examination results of the both methods showed that 12 people were positive (there were 4 people in Qianshan County and 8 people in Lingbi County) , and the positive rate was 1.94%. The rates of Cryptosporidium infection in the population of Qianshan County and Lingbi County were 1.24% (4/322) and 2.71% (8/295) respectively, and the difference had no statistical significance (P0.05). The single factor analysis found that the rate of Cryptosporidium infection was higher in the children and diarrhea patients; the multivariate logistics regression analysis indicated that the rate of Cryptosporidium infection was higher in the people who bred poultry and the diarrhea patients.The positive rate of serum antibody of Cryptosporidium in the population of the local area of Anhui Province is higher, which indicates that the previous infection is serious, and the rate of Cryptosporidium infection in human is relative to the age, diarrhea and whether there are poultries to be bred in the family, which is worthy of attention in the future prevention and treatment.

Oncomelania hupensis, which plays an important role in the transmission of schistosomiasis japonica, is the only intermediate host of Schistosoma japonicum, and carrying out studies on its subspecies differentiation and genetic variation will have an important significance for schistosomiasis control. In this paper, the research progress of taxonomy and discrimination techniques of O. hupensis is reviewed at four levels, namely the morphological level, the cellular level, the protein level, and the DNA molecule level, and DNA sequencing technology is considered as the ideal taxonomy and discrimination technique of O. hupensis and the future research emphasis.

Taking Populus tomentosa as an example, a methodology called elution-weighing-particle size-analysis (EWPA) was proposed to evaluate quantitatively the ability of retaining fine particulate matter (PM2.5, diameter d ≤ 2.5 μm) and atmospheric particulate matter by plant leaves using laser particle size analyzer and balance. This method achieved a direct, accurate measurement with superior operability about the quality and particle size distribution of atmospheric particulate matter retained by plant leaves. First, a pre-experiment was taken to test the stability of the method. After cleaning, centrifugation and drying, the particulate matter was collected and weighed, and then its particle size distribution was analyzed by laser particle size analyzer. Finally, the mass of particulate matter retained by unit area of leaf and stand was translated from the leaf area and leaf area index. This method was applied to a P. tomentosa stand which had not experienced rain for 27 days in Beijing Olympic Forest Park. The results showed that the average particle size of the atmospheric particulate matter retained by P. tomentosa was 17.8 μm, and the volume percentages of the retained PM2.5, inhalable particulate matter (PM10, d ≤ 10 μm) and total suspended particle (TSP, d ≤ 100 μm) were 13.7%, 47.2%, and 99.9%, respectively. The masses of PM2.5, PM10, TSP and total particulate matter were 8.88 x 10(-6), 30.6 x 10(-6), 64.7 x 10(-6) and 64.8 x 10(-6) g x cm(-2) respectively. The retention quantities of PM2.5, PM10, TSP and total particulate matter by the P. tomentosa stand were 0.963, 3.32, 7.01 and 7.02 kg x hm(-2), respectively.

To isolate and purify agglutinin from Oncomelania hupensis snail and determine its molecular weight.Agglutinin was preliminarily isolated from snail tissue homogenate by 0%-40% saturated ammonium sulfate, and then successively purified with Sephadex G-75 gel filtration and Sepharose 4B affinity chromatography. Bradford assay was used to determine the protein content. The agglutination activity was determined by rabbit erythrocytes. The purity of agglutinin preparations was assessed by SDS-PAGE. The molecular weight of agglutinin subunit was determined by Sephadex G-75 gel filtration.The specific activity of snail tissue homogenate was 21.74 titer/mg. After ammonium sulfate precipitation, Sephadex G-75 gel filtration and Sepharose 4B affinity chromatography, the specific activity of snail agglutinin from the homogenate solution increased to 61.93 titer/mg, 75.89 titer/mg and 963.86 titer/mg, respectively. SDS-PAGE analysis indicated that snail agglutinin (M, 53,000) was purified by Sephadex G-75 gel filtration and Sepharose 4B chromatography. The molecular weight of the snail agglutinin produced by Sephadex G-75 gel filtration was Mr 78,000.Combined use of salt fractionation, gel filtration and affinity chromatography can be efficient for extraction and purification of agglutinin from Oncomelania hupensis species. The snail agglutinin is characterized as mono subunit protein with a molecular weight of Mr 78,000.

To explore the risk factors of cerebral schistosomiasis japonica.A total of 37 confirmed cases, diagnosed during 1999-2004 in Anhui Province, were involved in the study as case group. Three controls for each case were selected from the general population either without schistosomiasis, with chronic schistosomiasis or with acute schistosomiasis. The relevant risk factors on the disease were analyzed.Four factors with labour intensity, physical, economical and nutritional conditions before illness between case group and normal control group, 7 factors including epilepsy history, hypersensitivity, intensity and times of infection between case group and acute schistosomiasis control group, 10 factors including intensity of infection, times of infection and treatment between case group and chronic schistosomiasis control group, all showed statistical significance (p0.05) . Five factors showed statistical significance (p0.05) between case group and the 3 control groups.The intensity of schistosome infection and treatment history are the main risk factors for cerebral schistosomiasis, and the physical and psychosocial conditions of the patients show some effect on the disease.

Schistosomiasis japonica was endemic in 12 provinces (including municipalities and autonomous regions) in the People's Republic of China (PR China). Despite the tremendous decrease of schistosomiasis incidence after almost 60 years of control, the distribution of snail-breeding sites has not been reduced significantly. In order to verify current transmission risks and identify the potential establishment of new foci of schistosomiasis driven by environmental changes, we conducted surveillance in selected risk areas of three provinces: Jiangsu, Anhui and Shandong from 2008 to 2010 in addition to routine snail surveillance. We investigated populations and possible reservoirs in sentinel sites and report that the total number of new acute cases did not diminish further in spite of ongoing control activities. In Anhui Province the local count compared to the national count was 43% (19/44) in 2008, 33% (25/75) in 2009 and 40% (17/42) in 2010. In all, 31.58 km(2) areas of snail breeding sites were newly detected nationwide through the year 2008-2010, of which the proportion of Anhui was 42% (5.03/11.98) in 2008, 95% (8.39/8.79) in 2009 and 79% (8.52/10.81) in 2010. Sentinel surveillance showed eight, nine and five confirmed cases of acute schistosomiasis in mobile populations (fishermen, migrant workers) in 2008, 2009 and 2010, respectively. All these cases were detected in Chaohu County, which must therefore be deemed an area at risk. We conclude that continuous surveillance with an emphasis on snails must be enhanced in potential risk areas in PR China.

To analyze the impact of large hydraulic projects on schistosomiasis transmission and evaluate the transmission risk in potential endemic areas.During 2008-2010, surveillance on risk factors related to schistosomiasis transmission and risk assessment were carried out in potential endemic sites in counties of Xuyu, Hongze, Jinhu, and Gaoyou in Jiangsu Province, Weishan County in Shangdong, Qianjiang City and Yiling District of Yichang City in Hubei, Juchao District of Chaohu City in Anhui Province, Wanzhou and Kaixian in Chongqing in Three Gorges Dam region or passed by South-to-North Water Diversion Project and Zhangjiagang City in Jiangsu Province located in lower reach of Yangtze River. At least one fixed and three temporary monitoring sites were set in each county (city or district). Local inhabitants aged 6-65 years old were screened by indirect haemagglutination assay (IHA) or ELISA, and the sero-positives were tested by Kato-Katz or miracidium hatching techniques to investigate possible infection in 2008. The endemic status of schistosomiasis in mobile population was surveyed every year during 2008-2010. Infection status in livestocks was surveyed in Juchao, Qianjiang, Gaoyou and Wanzhou Counties in 2008-2010. Oncomelania hupensis distribution was investigated in risky and suspicious areas. Snail spreading investigation was conducted through salvaging floater and snails-inducing by straw curtains in rivers connected with Yangtze River.8 256 local inhabitants were investigated by serological tests with a positive rate of 0.7% (60/8 256). Among the 60 serologically positive subjects, 55 individuals were examined by stool examination but none of them was egg positive. The antibody prevalence rate of migrating population in 2008-2010 was 2.0%, 1.4%, and 1.7%, respectively, with no significant difference (chi2 = 3.57, P0.05). Among the serologically positive subjects, egg-positive cases were found in migrating population in Juchao District each year and one case was found in Jinhu County in 2010. Oncomelania snails were only found in in Jinhu and Gaoyou without infected ones. A lot of aquatic shell-fish and snails were collected in the water floater and straw curtain without Oncomelania snails.Schistosomiasis is not endemic in the original nonendemic areas in Three Gorges Dam region and areas passed by South-to-North Water Diversion Project until now, but potential risk of transmission exists. Long term surveillance scheme on schistosomiasis should be established with varied monitoring factors in different category areas.

To understand the dynamic changes of the potential prevalent factors of schistosomiasis in Chaohu Lake area so as to provide forecast information on the outbreak of schistosomiasis in the area.From 2008 to 2010, fixed and mobile surveillance sites in potential endemic areas of Juchao District in Chaohu City, which was located in the southeast side of Chaohu Lake, were selected, and the schistosomiasis infection situation of local people, mobile population and livestock were investigated by immunological assays and/or stool examinations. The distribution of Oncomelania snails was surveyed in risk areas and suspicious areas, the spreading patterns of Oncomelania snails were observed in rivers that directly connected with the Yangtze River, and the Oncomelania snails were raised in the cages on the beaches of Chaohu Lake and a control area, and their survival and reproduction capacity was observed.In 2008, a total of 301 local people were screened by IHA, and there were no positives. From 2008 to 2010, a total of 321, 362 and 306 mobile population were examined by IHA, respectively, and the positive rate of antibody were 3.74%, 4.97% and 2.94%, respectively. The antibody positives were tested by stool examinations, and the positive rates were 66.67%, 50% and 55.56%, respectively. A total of 91 local livestock and 92 livestock from endemic areas were examined respectively by the miracidium hatching method, and there were no positives. A total of 97.8 hm2 risk areas and 193.62 hm2 suspicious areas in the potential endemic area were surveyed respectively, but no Oncomelania snails were found. The investigation results on snail spreading patterns indicated that snails could spread into Chaohu Lake by adsorbing on floating debris. The field study revealed that Oncomelania snails could survive and reproduce in the Lake.The imported infectious sources of schistosomiasis have been found in Chaohu Lake area, and the higher possibility of imported Oncomelania snails spreading into the Lake and surviving and reproducing in the lake is predicted. Therefore, effective measures should be taken to decrease the risks of schistosomiasis transmission in the potential endemic area.

This paper presents an analysis of research progress of schistosomiasis in China, demonstrates the research needs of schistosomiasis control, and put forwards the research priority and prospect during the 12th Five-Year Plan period.

In this paper, a new approach is proposed to simulate images impacted by the Aero-Optical Effect (AOE) of High-Speed Flow Field. We first study the mechanism of the Aero-Optical Effect of High-Speed Flow Field, and its influence on the imaging system of the aircrafts. After reviewing existing methods of simulating blurred images impacted by the AOE, we show a novel method of simulating uneven blurred images which makes a great contrast to the traditional algorithms. Experimental results indicate that the blurred images generated by our methods are much closer to authentic situations than the previous results.

To investigate the possibility of spread of snails and transmission of schistosomiasis japonica due to the construction of water transfer project from Yangtze River to Huaihe River.In order to understand the current endemic situation of schistosomiasis in the project area, the distribution of snails was surveyed by routine methods, level of anti-schistosome antibody in human sera was detected by indirect haemagglutination test (IHA), and the prevalence of schistosomiasis in cattle was detected by egg hatching method. The snail survival and reproduction were observed in Chaohu Lake area(experimental area) and a control area for one year.Snail density was high in two starting points, from where the water in Yangtze River will be directed to Huaihe River. In counties of Wuwei and Hexian, through which the project will be built, the positive rate of anti-schistosome antibody in residents was 22.11% (168/760) and 18.59% (37/199), schistosomiasis prevalence in cattle was 2.42% (9/371) and 0.2% (2/997), respectively. Schistosomiasis was also endemic in Juchao District of Chaohu City. Snails respectively from grassland and hilly area were collected and put in Chaohu Lake for breed and newborn snails were found one year later. During the egg-laying season, the survival rate of snails from grassland in 2 experiment areas and a control area was 11.3%-16.7%, 3.0%-20.8% and 4.7%-14.7% respectively (chi2 = 0.093, 0.760, P0.05; chi2 = 0.647, 0, P0.05), and that of snails from hilly area was 24.1%-44.4%, 37.8%-67.3% and 86.3%-93.1% respectively (chi2 = 9.575, 5.302, P0.05; chi2 = 56.863, 36.218, P0.05). There was no significant difference between the experimental area and the control area on the number of eggs in the ovaries of the same type female snails.The one-year observation reveals that the construction of the project might result in spread of snails and transmission of schistosomiasis japonica in the relevant areas.