Amalgamation (sluice methods) used in the extraction of golds from ores and concentrates causes mercury contamination of the environment, which is increasingly concerned in China. The mercury specific consumption in ...Amalgamation (sluice methods) used in the extraction of golds from ores and concentrates causes mercury contamination of the environment, which is increasingly concerned in China. The mercury specific consumption in the technical procedures has been evaluated based on the investigation of 33 mines. The average consumption of Hg is 14.6 g/ton raw ores, the ratio of Hg to gold is 6.35 g(Hg)/g(Au), total consumption of Hg in 1995 was 80 tons. The mercury amount entering into environment was 20 tons/a. Up to now 13.26% total gold produced in China is still using amalgamation, although prohibition of amalgamation since 1985 was officially proclaimed. At present, the amalgamation usage tendds to go up in some companies becasue of the benefic promotion. The irreversible mercury consumption was dispersed in the air(50%), tailing (23%) and partly(27%) entered into the downward products in the production, such as ore concentrates which was refined in the plants and caused pollution of environment near the smelter.展开更多
Background Overactive bladder （OAB） can be caused by many factors such as inflammation,bladder outlet obstruction,neurogenic factors.We performed an intraperitoneal （ip） injection of cyclophosphamide to induce cys...Background Overactive bladder （OAB） can be caused by many factors such as inflammation,bladder outlet obstruction,neurogenic factors.We performed an intraperitoneal （ip） injection of cyclophosphamide to induce cystitis in rats,which causes their detrusors to overact,to provide a valuable disease model for discussing OAB pathogenesis and to study effective curing methods.Methods Female Sprague-Dawley rats were induced to form cystitis by cyclophosphamide （200 mg/kg,ip）.The day after the injection,two catheters were inserted into each rat＇s bladder to study its urodynamics.The BL-410 model bio-function experimental system was used to monitor bladder pressure while the rats were conscious.Unstable detrusor contractions appear in the urine storage period as a standard to determine OAB,and the positive rate was calculated.Urodynamic parameters such as bladder basal pressure （BP）,maximum voiding pressure （MVP）,intercontraction interval （ICI）,spontaneous activity （SA）,maximum cystometric capacity （MCC）,and bladder compliance （BC） were recorded in each group,and a light microscope was used to observe the pathological changes in the rat bladder tissue.Results The detrusor instability rate of the model group was 83.33%.The MVP,MCC and BC of rats in the model group were lower than the control group （P 〈0.01）,and the BP,ICI and SA of the model group rats were higher than the control group （P 〈0.01）.The difference between the control group and the model group is statistically significant.The model group rats＇ bladder walls swelled and bled,the submucosa thickened and leukocyte infiltration became serious.Conclusions Acute cystitis and OAB symptoms can be induced by ip injections of cyclophosphamide in rats.This can provide a valuable animal model to study OAB in human beings.展开更多
文摘Amalgamation (sluice methods) used in the extraction of golds from ores and concentrates causes mercury contamination of the environment, which is increasingly concerned in China. The mercury specific consumption in the technical procedures has been evaluated based on the investigation of 33 mines. The average consumption of Hg is 14.6 g/ton raw ores, the ratio of Hg to gold is 6.35 g(Hg)/g(Au), total consumption of Hg in 1995 was 80 tons. The mercury amount entering into environment was 20 tons/a. Up to now 13.26% total gold produced in China is still using amalgamation, although prohibition of amalgamation since 1985 was officially proclaimed. At present, the amalgamation usage tendds to go up in some companies becasue of the benefic promotion. The irreversible mercury consumption was dispersed in the air(50%), tailing (23%) and partly(27%) entered into the downward products in the production, such as ore concentrates which was refined in the plants and caused pollution of environment near the smelter.
文摘Background Overactive bladder （OAB） can be caused by many factors such as inflammation,bladder outlet obstruction,neurogenic factors.We performed an intraperitoneal （ip） injection of cyclophosphamide to induce cystitis in rats,which causes their detrusors to overact,to provide a valuable disease model for discussing OAB pathogenesis and to study effective curing methods.Methods Female Sprague-Dawley rats were induced to form cystitis by cyclophosphamide （200 mg/kg,ip）.The day after the injection,two catheters were inserted into each rat＇s bladder to study its urodynamics.The BL-410 model bio-function experimental system was used to monitor bladder pressure while the rats were conscious.Unstable detrusor contractions appear in the urine storage period as a standard to determine OAB,and the positive rate was calculated.Urodynamic parameters such as bladder basal pressure （BP）,maximum voiding pressure （MVP）,intercontraction interval （ICI）,spontaneous activity （SA）,maximum cystometric capacity （MCC）,and bladder compliance （BC） were recorded in each group,and a light microscope was used to observe the pathological changes in the rat bladder tissue.Results The detrusor instability rate of the model group was 83.33%.The MVP,MCC and BC of rats in the model group were lower than the control group （P 〈0.01）,and the BP,ICI and SA of the model group rats were higher than the control group （P 〈0.01）.The difference between the control group and the model group is statistically significant.The model group rats＇ bladder walls swelled and bled,the submucosa thickened and leukocyte infiltration became serious.Conclusions Acute cystitis and OAB symptoms can be induced by ip injections of cyclophosphamide in rats.This can provide a valuable animal model to study OAB in human beings.
