12 perfluorinated compounds（PFCs） in human blood from workers in a textile mill in Shandong province and several barbershops in Tianjin were analyzed in this study. It was found that perfluorooctanesulfonate（PFOS）...12 perfluorinated compounds（PFCs） in human blood from workers in a textile mill in Shandong province and several barbershops in Tianjin were analyzed in this study. It was found that perfluorooctanesulfonate（PFOS） and perfluorooctanoate（PFOA） were the most prominent PFCs, with average concentrations of 5.73 mg/L and 5.46 mg/L for textile workers, and 2.55 mg/L and 2.84 mg/L for barbers.PFOS and perfluorohexanesulfonate（PFHxS） concentrations revealed a positive correlation in blood samples（p 〈 0.01）, and concentrations among PFOS, perfluorononanoic acid（PFNA） and perfluorodecanoic acid（PFDA） also revealed positive correlations（p 〈 0.01）. The influence of gender and age on PFC concentration in blood was also investigated, and the results showed that there was no statistically significant difference between the male and female samples, as well as in samples from people with different ages. Generally speaking, the textile workers展开更多
The clinical diagnosis of trichinellosis is difficult because its clinical manifestations are nonspecific.Detection of anti-Trichinella IgG by ELISA using T.spiralis muscle larval excretory-secretory(ES)antigens is th...The clinical diagnosis of trichinellosis is difficult because its clinical manifestations are nonspecific.Detection of anti-Trichinella IgG by ELISA using T.spiralis muscle larval excretory-secretory(ES)antigens is the most commonly used serological method for diagnosis of trichinellosis,but the main disadvantage is false negativity during the early stage of infection.There is an obvious window period between Trichinella infection and antibody positivity.During the intestinal stage of Trichinella infection,the ES antigens of intestinal worms(intestinal infective larvae and adults)are exposed to host’s immune system at the earliest time and elicit the production of specific anti-Trichinella antibodies.Anti-Trichinella IgG antibodies in infected mice were detectable by ELISA with ES antigens of intestinal worms as soon as 8-10 days post infection(dpi),but ELISA with muscle larval ES antigens did not permit detection of infected mice before 12 dpi.Therefore,the new early antigens from T.spiralis intestinal worms should be screened,identified and characterized for early serodiagnosis of trichinellosis.展开更多
An automated approach is proposed for a microassembly task, which is to insert a 10 μm diameter glass tube into a 12 μm diameter hole in a silicon substrate, and bond them together with ultraviolet （UV） curable ad...An automated approach is proposed for a microassembly task, which is to insert a 10 μm diameter glass tube into a 12 μm diameter hole in a silicon substrate, and bond them together with ultraviolet （UV） curable adhesive. Two three-degree-of-freedom micromanipulators axe used to move the glass tube and the dispensing needle, respectively. Visual feedback is provided by an optical microscope. The angle of the microscope axis is precisely calibrated using an autofocus strategy. Robust image segmentation method and feature extraction algorithm are developed to obtain the features of the hole, the glass tube and the dispensing needle. Visual servo control is employed to achieve accurate aligning for the tube and the hole. Automated adhesive dispensing is used to bond the glass tube and the silicon substrate together after the insertion. On-line monitoring ensures that the diameter of the adhesive spot is within a desired range. Experimental results demonstrate the effectiveness of the proposed strategy.展开更多
An on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry method for the analysis of perfluoroalkyl substances（PFASs） in water samples was developed.The optimal analytical con...An on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry method for the analysis of perfluoroalkyl substances（PFASs） in water samples was developed.The optimal analytical conditions were obtained through the optimization of the extraction efficiency of online solid phase extraction column,sample loading rate and loading volume,and the concentration of ammonium acetate in mobile phase.Under the optimal condition,the analytical method displayed good linearity（r^2〉0.99） for 12 PFASs（C5-C14 perfluoroalkyl carboxylic acids and C6/C8 perfluoroalkyl sulfonic acids） over a concentration range of 0.5-100 ng/L.The limits of quantitation for samples were between 0.025 ng/L and 0.5 ng/L and the relative standard deviations（RSD） of five consecutive analyses were less than 10%for 1 ng/L standard solution.Satisfactory results were obtained using this analytical method for the analysis of perfluoroalkyl substances in Antarctic ice core samples.The recoveries of all perfluoroalkyl substances were in a range of 73%-117%when the samples were spiked with standards at the concentrations of 2.5 ng/L and 25 ng/L.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 41023005, 21377145, 21321004)the State Environmental Protection Welfare Scientific Research Project (No. 201009026)
文摘12 perfluorinated compounds（PFCs） in human blood from workers in a textile mill in Shandong province and several barbershops in Tianjin were analyzed in this study. It was found that perfluorooctanesulfonate（PFOS） and perfluorooctanoate（PFOA） were the most prominent PFCs, with average concentrations of 5.73 mg/L and 5.46 mg/L for textile workers, and 2.55 mg/L and 2.84 mg/L for barbers.PFOS and perfluorohexanesulfonate（PFHxS） concentrations revealed a positive correlation in blood samples（p 〈 0.01）, and concentrations among PFOS, perfluorononanoic acid（PFNA） and perfluorodecanoic acid（PFDA） also revealed positive correlations（p 〈 0.01）. The influence of gender and age on PFC concentration in blood was also investigated, and the results showed that there was no statistically significant difference between the male and female samples, as well as in samples from people with different ages. Generally speaking, the textile workers
基金This work was supported by the National Natural Science Foundation of China(no.81572024 and 81672043)The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘The clinical diagnosis of trichinellosis is difficult because its clinical manifestations are nonspecific.Detection of anti-Trichinella IgG by ELISA using T.spiralis muscle larval excretory-secretory(ES)antigens is the most commonly used serological method for diagnosis of trichinellosis,but the main disadvantage is false negativity during the early stage of infection.There is an obvious window period between Trichinella infection and antibody positivity.During the intestinal stage of Trichinella infection,the ES antigens of intestinal worms(intestinal infective larvae and adults)are exposed to host’s immune system at the earliest time and elicit the production of specific anti-Trichinella antibodies.Anti-Trichinella IgG antibodies in infected mice were detectable by ELISA with ES antigens of intestinal worms as soon as 8-10 days post infection(dpi),but ELISA with muscle larval ES antigens did not permit detection of infected mice before 12 dpi.Therefore,the new early antigens from T.spiralis intestinal worms should be screened,identified and characterized for early serodiagnosis of trichinellosis.
基金supported by National Natural Science Foundation of China under(Nos.61227804 and 61105036)
文摘An automated approach is proposed for a microassembly task, which is to insert a 10 μm diameter glass tube into a 12 μm diameter hole in a silicon substrate, and bond them together with ultraviolet （UV） curable adhesive. Two three-degree-of-freedom micromanipulators axe used to move the glass tube and the dispensing needle, respectively. Visual feedback is provided by an optical microscope. The angle of the microscope axis is precisely calibrated using an autofocus strategy. Robust image segmentation method and feature extraction algorithm are developed to obtain the features of the hole, the glass tube and the dispensing needle. Visual servo control is employed to achieve accurate aligning for the tube and the hole. Automated adhesive dispensing is used to bond the glass tube and the silicon substrate together after the insertion. On-line monitoring ensures that the diameter of the adhesive spot is within a desired range. Experimental results demonstrate the effectiveness of the proposed strategy.
基金supported by the National Natural Science Foundation of China(Nos.21377145,21321004)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB01020300)
文摘An on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry method for the analysis of perfluoroalkyl substances（PFASs） in water samples was developed.The optimal analytical conditions were obtained through the optimization of the extraction efficiency of online solid phase extraction column,sample loading rate and loading volume,and the concentration of ammonium acetate in mobile phase.Under the optimal condition,the analytical method displayed good linearity（r^2〉0.99） for 12 PFASs（C5-C14 perfluoroalkyl carboxylic acids and C6/C8 perfluoroalkyl sulfonic acids） over a concentration range of 0.5-100 ng/L.The limits of quantitation for samples were between 0.025 ng/L and 0.5 ng/L and the relative standard deviations（RSD） of five consecutive analyses were less than 10%for 1 ng/L standard solution.Satisfactory results were obtained using this analytical method for the analysis of perfluoroalkyl substances in Antarctic ice core samples.The recoveries of all perfluoroalkyl substances were in a range of 73%-117%when the samples were spiked with standards at the concentrations of 2.5 ng/L and 25 ng/L.
