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Objective To investigate the effect of the angle correction factors of ionization chamber array Matrixx on the dosimetric verification of volumetric modulated arc therapy plan.Methods The Matrixx (IBA)was put in the middle of the MultiCube Phantom. Computed tomography scan was performed and the results were sent to the Raystation treatment planning system(TPS). All data calculated from TPS and actually measured using MatriXX were gained under the following conditions:6 MV,100 MU,28 cm×28 cm radiation field. And the directions of beam were from 0°to 180°with an interval of 5°(except an interval of 1° from 85° to 95°). The angle correction factors(CF)(θ)cor of MatriXX were calculated by the calculated dose values from TPS and the measured values using MatriXX and then mirrored to the opposite side. CF (θ)cor values were compared with CF(θ)def values that were given by manufacturer. The comparison was made by paired t-test. Results CF(θ)cor and CF(θ)def were different, and the difference was significant between 85° and 95°,with a maximum of 7.5%(P<0.05). The CF(θ)cor correction method had a higher gamma pass rate than the CF(θ)def correction method,with a maximum of 17%(P<0.05). Conclusions The ionization chamber array MatriXX has an angular dependence and the angle correction should be performed.The angle correction factors have the individual characteristics and are different in every unit ionization chamber of the MatriXX. Therefore, it is necessary to do angle correction for every unit ionization chamber of the MatriXX and the possible errors caused by various factors should be considered in order to improve the accuracy rate and gamma pass rate of the plan verification.
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Objective To evaluate the effect of schistosomiasis control in“Oriental Star shipwreck event”in Jianli County, Hubei Province,so as to provide experiences for schistosomiasis prevention and control in rescue of emergency in the future. Methods According to the data of historical schistosomiasis prevalence and the results of the field survey in the townships in the upstream and downstream of the rescue spots,the emergency handling measures of schistosomiasis control were evaluated. Meanwhile,the Oncomelania hupensis snail situation,priority crowd chemotherapy,key aquatic monitoring,and illness moni?toring of people and livestock were investigated to evaluate the schistosomiasis control effect after the events comprehensively. Results There were no schistosome?infected snails found in the place of shipwreck and the rescue spots. The average density of O. hupensis snails in 5 townships of Jianli County was 0.064 snails/0.1 m2 ,and there were no infected snails found. The positive rate of 2 090 migrants in the schistosomiasis serologic tests was 0.29%and there were no positive ones found in the fecal exami?nation. There were no acute schistosomiasis cases found by the sentinel surveillance fever clinics,and also no positive cattle were found. The results of sentinel mice monitoring in the place of shipwreck and 4 villages in the upstream and downstream showed no infected mice were found. Conclusion The schistosomiasis control measures taken after the shipwreck is effective, which achieves the goal of no schistosomiasis transmission after emergency.
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Objective To investigate the current situation of management of institutions of schistosomiasis prevention and control in Hubei Province so as to explore the probable competency building standards for these institutions at the county and township levels. Methods By using a combination of quantitative and qualitative methods the institutions of schistosomiasis prevention and control at county and township levels were investigated for the institutional setup staffing and fulfillment func-tions since the reform of 2004. Results Among 63 schistosomiasis endemic counties cities districts of Hubei Province there were 26 independent schistosomiasis control institutions 41.27% there were 24 institutions which were incorporated in-to CDC 38.10% and there were no institutions in 13 counties 20.63% . Among 518 endemic towns there were 299 institu-tions 57.72% . The total staffing size were 1 932 but there were 1 586 82.09% people actually working in the post and therefore there were 346 17.91% empty positions. The average rates of carrying out the six functions were 91.48%-71.19%but only 19.23%of the institutions participated in the comprehensive schistosomiasis control management project and its effect assessment. Conclusion According to the management model for schistosomiasis control institutions under the current institu-tional mechanisms we need a rigorous industry standard to constrain guide and standardize the management and capacity-building of the institutions in different historical periods.
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Objective To understand the human resources of the grassroots institutions of schistosomiasis control and pre?vention so as to provide the evidence for formulating the standards of institutional capacity?building. Methods By using the combination of quantitative and qualitative methods the hierarchy of schistosomiasis control institution workers structural fea?tures of workers and benefits of workers were investigated and the results were analyzed statistically after the 2004 reform. Re?sults The constituent ratios of personnel≤30 years old 30 to 45 years old and≥45 years old were 6.8% 64.0%and 29.2%respectively with an average age of 43.1 years. For education levels 61.35%of the personnel had secondary or high school lev?els. At the city level the structural proportion of the senior professional medium professional and primary professional titles was 1.4∶5.6∶3.0 and at the county level the proportion was 0.5∶6.1∶3.4. There was 14 200 yuan per capita at the township schistosomiasis control institutions. Conclusion The technology of the personnel in schistosomiasis institutions of Hubei Prov?ince is weak the average age of personnel is old and the salary is low.
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Objective To compare the molluscicidal effects between“Luo-wei”(TDS),a plant molluscicide in 4 percent, and metaldehyde and niclosamide(MNSC)in the field. Methods A natural ecological environment with Oncomelania hupensis was selected as the test area,the test concentrations of TDS and MNSC were 2.5 g/m3 and 2 ml/m3 respectively by the immersion method;the test doses of TDS and MNSC were 3 g/m2 and 2 ml/m2 respectively by the spray method;the doses of WPN in a control group were 2 g/m3 and 2 g/m2 respectively by the two methods above-mentioned. The molluscicidal effects between TDS and MNSC were compared by using the synchronous design method and parallel comparative method. Results In the TDS group,the death rate of snails was 90.70%by immersion for 24 hours,reached to 81.40%after spraying for 7 days,and there were no significant differences among the observation time points in molluscicidal effects(P>0.05). One day after the spraying,the death rate of snails was less in the TDS group compared with that in the MSCN group(P0.05). In the MSCN group,the death rate of snails was 99.17%by immersion for 24 hours,reached to 66.07% by spraying for 1 day. In the WPS group,the death rate of snails was 97.15% by immersion for 24 hours,reached to 71.43%after spraying for 1 day,and there were no significant differences(both P>0.05). Conclusion TDS has a good molluscicidal activity and stable efficacy,and the molluscicidal effect of TDS is similar to that of MSCN in the filed, but the molluscicidal sensitivity of TDS is lower than that of MSCN.