Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial s...Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.展开更多
程序似然不变量是程序中隐含的属性,可以应用于程序验证、软件测试技术、逆向工程等领域。针对自动化测试工具C++Test产生的测试用例集,利用程序不变量分析工具Daikon判断这些测试用例是否改变了当前的不变量;并将两种工具结合生产一种...程序似然不变量是程序中隐含的属性,可以应用于程序验证、软件测试技术、逆向工程等领域。针对自动化测试工具C++Test产生的测试用例集,利用程序不变量分析工具Daikon判断这些测试用例是否改变了当前的不变量;并将两种工具结合生产一种自动化测试用例集约简工具CDRT(C++Test And Daikon Reduction Testing),从而达到约简测试用例集的效果,再通过变异测试工具INSURE++对简化后的测试用例集进行评估。实验结果表明,CDRT工具能有效地约简测试用例集。展开更多
Objective To determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC). Methods The synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were ...Objective To determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC). Methods The synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were studied using single cell gel electrophoresis (SCGE) assay (comet assay) and cytokinesis-blocked micronucleus (CBMN) test in vitro. The whole blood cells from a male donor and a female donor were either only exposed to 2450-MHz microwaves (5.0 mW/cm2) for 2 h or only exposed to MMC (0.0125 μ/mL, 0.025 μg/mL, 0.05μg/mL and 0.1 μg/mL) for 24 h; and the samples were exposed to MMC for 24 h after exposure to MW for 2 h. Results In the comet assay, the comet lengths ( 29.1 μm and 25.9 μm) of MW were not significantly longer than those (26.3 μrn and 24.1 μm) of controls (P>0.05). The comet lengths (57.4 μm, 68.9 μm, 91.4 μm, 150.6μm and 50.6 μm, 71.7μm, 100.1 μm, 145.1 μm) of 4 MMC groups were significantly longer than those of controls (P<0.01). The comet lengths (59.1 μm, 92.3 μm, 124.5 μm, 182.7 μm and 57.4 μm, 85.5 μm, 137.5 μm, 178.3 μm) of 4 MW plus MMC groups were significantly longer than those of controls too (P<0.01). The comet lengths of MW plus MMC groups were significantly longer than those of the corresponding MMC doses (P<0.05 or P<0.01) when the doses of MMC were ≥50.025 μg/mL. In the CBMN, the micronucleated cell (MNC) rates of MW were 5% and 6%, which showed no difference compared with those (4‰ and 4‰) of controls (P>0.05). The MNC rates of 4 MMC groups were 8‰, 9‰, 14‰, 23‰ and 8‰, 8‰, 16‰, 30‰ respectively. When the doses of MMC were 3≥0.05 μg/mL, MNC rates of MMC were higher than those of controls (P<0.05). MNC rates of 4 MW plus MMC groups were 12‰, 13‰, 20‰, 32‰ and 8‰, 9‰, 23‰, 40‰. When the doses of MMC were 5≥0.05 μg/mL, MNC rates of MW plus MMC groups were much higher than those of controls (P<0.01). MNC rates of 4 MW plus MMC groups were not significantly higher than those of the corresponding MMC doses. Conclusion The low-intensity 2450-MHz microwave radiation can not induce DNA and chromosome damage, but can increase DNA damage effect induced by MMC in comet assay.展开更多
Light hydrocarbon (methane, ethane, propane, butane and CO2) test and C isotopic analysis of CO are conducted for over 100 lower-layer atmospheric samples from the East China Sea slope and the Okinawa Trough. The resu...Light hydrocarbon (methane, ethane, propane, butane and CO2) test and C isotopic analysis of CO are conducted for over 100 lower-layer atmospheric samples from the East China Sea slope and the Okinawa Trough. The results show that the lower-layer atmosphere mainly consists of CO2 and then of CH4, and the CO2 concentrations are calculated to have a high average value of 0.87 omega/10(-2) about three times that of the regional background (0-3 omega/10(-2)). The result also shows that the average value of C isotope - 20.8 x 10(-3) is given to the CO2, inferring that it is inorganic gas. Thus, for the future 's work in the Okinawa Trough, special attention should be paid to CO2 hydrate, which is very possibly an important hydrate type.展开更多
AIM To investigate hepatitis C virus(HCV) testing recommendations from the United States and other high-income countries.METHODS A comprehensive search for current HCV testing recommendations from the top quartile of ...AIM To investigate hepatitis C virus(HCV) testing recommendations from the United States and other high-income countries.METHODS A comprehensive search for current HCV testing recommendations from the top quartile of United Nations Human Development Index(HDI) countries(very high HDI) was performed using Google and reviewed from May 1-October 30, 2014 and re-reviewed April 1-October 2, 2017. RESULTS Of the 51 countries identified, 16 had HCV testing recom-mendations from a government body or recommendations issued collaboratively between a government and a medical organization. Of these 16 countries, 15 had HCV testing recommendations that were primarily risk-based and highlight behaviors, exposures, and conditions that are associated with HCV transmission in that region. In addition to risk-based testing, the HCV Guidance Panel(United States) incorporates recommendations for aone-time test for individuals born during 1945-1965(the birth cohort) without prior ascertainment of risk into their guidance. In addition to the United States, six other countries either have an age-based testing recommendation or recommend one-time testing for all adults independent of risk factors typical of the region. CONCLUSION This review affirmed the similarities of the HCV Guidance Panel's guidance with those of recommendations from very high HDI countries.展开更多
In this paper, ultrasonic C-scan test of spot welds for stainless steel has been studied. It is concluded that large scanning step length contributes to high testing efficiency, however, the low-resolution C-scan imag...In this paper, ultrasonic C-scan test of spot welds for stainless steel has been studied. It is concluded that large scanning step length contributes to high testing efficiency, however, the low-resolution C-scan image generated cannot be used to assess spot welding quality reliably. Based on bicubic image interpolation, the C-scan image in low resolution with the large step length 1 000 ~xm is subdivided and reconstructed. By this means, the C-scan image resolution is greatly enhanced and testing results obtained are satisfactory, realizing rapid assessment of spot welds. The results of rapid ultrasonic C-scan test fit the actual metallographic measured value well. Mean value of normal distribution of error statistics is O. 006 67, and the standard deviation is O. 087 11. Rapid ultrasonic C-scan test based on image interpolation is of high accuracy and excellent stability.展开更多
The tensile properties of three different carbonfiberreinforced carbon composites (C/C), mat C/C, 2D laminate and 4D C/C, were investigated under the combined influence of temperature and loading rate. From the experi...The tensile properties of three different carbonfiberreinforced carbon composites (C/C), mat C/C, 2D laminate and 4D C/C, were investigated under the combined influence of temperature and loading rate. From the experiments the following could be concluded: loading rate between 10-1-10 mm/min was valid; the fracture stress of the three kinds of C/C composites increased with increasing temperature in the range from room temperature to 1900, and the initial modulus of 2D laminate C/C composites increased with the increase of temperature up to 2000.展开更多
A capsulated microdose 14C-urea breath test (14C-UBT) was developed to detect Helicobacter pylori (HP) infection in 137 patients (54 HP negative and 83 HP positive individuals)to whom a single dose of 3. 7ｘ 104 Bq of...A capsulated microdose 14C-urea breath test (14C-UBT) was developed to detect Helicobacter pylori (HP) infection in 137 patients (54 HP negative and 83 HP positive individuals)to whom a single dose of 3. 7ｘ 104 Bq of 14C-urea in a capsule was given. Samples of exhaled gas were collected at the sib, 10th, 15th. 20th, 25th, 30th, 45th and 60th minute after the administration and the peak value of exhaled 14CO2 was found in the samples collected at the 25th minute. This peak value was taken as the measuring point and directly expressed as Bq/mmol CO2 to develop a new detecting method. Then its results were compared with those of HP culture and histological examination. It was found that the samples collected on the 25th minute showed a sensitivity of 97. 06%, specificity of 95. 12%, positive predictive value of 97. 06% and negative predictive value of 95. 12% respectively when the mean value of 14CO2 in HP negative subjects ±3s on the 25th minute was taken as the critical value. This suggests that the capsule-based microdose 14C-UBT may replace conventional 14C-UBT using a larger dose of (1. 85-3. 7)ｘ 105 Bq for it is non-invasive, safe, rapid, accurate, simple and economic.展开更多
It is important to reveal the performance of carbon/carbon composites subjected to complex loading, which can provide a basis for developing the failure laws of carbon/carbon composites. The uniaxial and biaxial compr...It is important to reveal the performance of carbon/carbon composites subjected to complex loading, which can provide a basis for developing the failure laws of carbon/carbon composites. The uniaxial and biaxial compressive performances of three-dimensional reinforced carbon/carbon composites (3D C/C) were investigated in this paper. The results showed that the compressive strength becomes larger when the loading direction parallels to the z-direction of 3D C/C. The uniaxial compression failure was mainly caused by fracture fiber bundles to form an overall shear fault in the z-direction. The failure mode was delamination of fiber bundle/matrix interface for the x- and y-direction samples. The biaxial compressive failure of x-y direction compressioncompression specimen was caused by the low interlaminar shear strength. In addition,for y-z and z-x direction compression-compression samples,the shear-type failure was formed on the surface of the specimen plumbing the loading direction. Overall,the weak-interface is still a main factor to influent the fracture mechanism of 3D C/C.展开更多
文摘Screening tests for blood donations are based upon sensitivity, cost-effectiveness and their suitability for high-throughput testing. Enzyme immunoassay (EIAs) for hepatitis C virus (HCV) antibodies were the initial screening tests introduced. The ”first generation“ antibody EIAs detected seroconversion after unduly long infectious window period. Improved HCV antibody assays still had an infectious window period around 66 d. HCV core antigen EIAs shortened the window period considerably, but high costs did not lead to widespread acceptance. A fourth-generation HCV antigen and antibody assay (combination EIA) is more convenient as two infectious markers of HCV are detected in the same assay. Molecular testing for HCV-RNA utilizing nucleic acid amplification technology (NAT) is the most sensitive assay and shortens the window period to only 4 d. Implementation of NAT in many developed countries around the world has resulted in dramatic reductions in transfusion transmissible HCV and relative risk is now < 1 per million donations. However, HCV serology still continues to be retained as some donations are serology positive but NAT negative. In resource constrained countries HCV screening is highly variable, depending upon infrastructure, trained manpower and financial resource. Rapid tests which do not require instrumentation and are simple to perform are used in many small and remotely located blood centres. The sensitivity as compared to EIAs is less and wherever feasible HCV antibody EIAs are most frequently used screening assays. Efforts have been made to implement combined antigen-antibody assays and even NAT in some of these countries.
文摘程序似然不变量是程序中隐含的属性,可以应用于程序验证、软件测试技术、逆向工程等领域。针对自动化测试工具C++Test产生的测试用例集,利用程序不变量分析工具Daikon判断这些测试用例是否改变了当前的不变量;并将两种工具结合生产一种自动化测试用例集约简工具CDRT(C++Test And Daikon Reduction Testing),从而达到约简测试用例集的效果,再通过变异测试工具INSURE++对简化后的测试用例集进行评估。实验结果表明,CDRT工具能有效地约简测试用例集。
基金This work was supported by the Natural Science Foundation of Zhejiang Province (No.300434), 2001-2003, and International Cooperation Foundation of Science-Technique Bureau of Zhejiang Province (No. 012104), 2001-2002.
文摘Objective To determine the interaction between 2450-MHz microwaves (MW) radiation and mitomycin C (MMC). Methods The synergistic genotoxic effects of low-intensity 2450-MHz microwave and MMC on human lymphocytes were studied using single cell gel electrophoresis (SCGE) assay (comet assay) and cytokinesis-blocked micronucleus (CBMN) test in vitro. The whole blood cells from a male donor and a female donor were either only exposed to 2450-MHz microwaves (5.0 mW/cm2) for 2 h or only exposed to MMC (0.0125 μ/mL, 0.025 μg/mL, 0.05μg/mL and 0.1 μg/mL) for 24 h; and the samples were exposed to MMC for 24 h after exposure to MW for 2 h. Results In the comet assay, the comet lengths ( 29.1 μm and 25.9 μm) of MW were not significantly longer than those (26.3 μrn and 24.1 μm) of controls (P>0.05). The comet lengths (57.4 μm, 68.9 μm, 91.4 μm, 150.6μm and 50.6 μm, 71.7μm, 100.1 μm, 145.1 μm) of 4 MMC groups were significantly longer than those of controls (P<0.01). The comet lengths (59.1 μm, 92.3 μm, 124.5 μm, 182.7 μm and 57.4 μm, 85.5 μm, 137.5 μm, 178.3 μm) of 4 MW plus MMC groups were significantly longer than those of controls too (P<0.01). The comet lengths of MW plus MMC groups were significantly longer than those of the corresponding MMC doses (P<0.05 or P<0.01) when the doses of MMC were ≥50.025 μg/mL. In the CBMN, the micronucleated cell (MNC) rates of MW were 5% and 6%, which showed no difference compared with those (4‰ and 4‰) of controls (P>0.05). The MNC rates of 4 MMC groups were 8‰, 9‰, 14‰, 23‰ and 8‰, 8‰, 16‰, 30‰ respectively. When the doses of MMC were 3≥0.05 μg/mL, MNC rates of MMC were higher than those of controls (P<0.05). MNC rates of 4 MW plus MMC groups were 12‰, 13‰, 20‰, 32‰ and 8‰, 9‰, 23‰, 40‰. When the doses of MMC were 5≥0.05 μg/mL, MNC rates of MW plus MMC groups were much higher than those of controls (P<0.01). MNC rates of 4 MW plus MMC groups were not significantly higher than those of the corresponding MMC doses. Conclusion The low-intensity 2450-MHz microwave radiation can not induce DNA and chromosome damage, but can increase DNA damage effect induced by MMC in comet assay.
文摘Light hydrocarbon (methane, ethane, propane, butane and CO2) test and C isotopic analysis of CO are conducted for over 100 lower-layer atmospheric samples from the East China Sea slope and the Okinawa Trough. The results show that the lower-layer atmosphere mainly consists of CO2 and then of CH4, and the CO2 concentrations are calculated to have a high average value of 0.87 omega/10(-2) about three times that of the regional background (0-3 omega/10(-2)). The result also shows that the average value of C isotope - 20.8 x 10(-3) is given to the CO2, inferring that it is inorganic gas. Thus, for the future 's work in the Okinawa Trough, special attention should be paid to CO2 hydrate, which is very possibly an important hydrate type.
基金Supported by Centers for Disease Control and Prevention,contract No.200-2013-M-57552the Johns Hopkins University Center for AIDS Research,No.1P30AI094189NIDA,No.R37DA013806(to Thomas DL)
文摘AIM To investigate hepatitis C virus(HCV) testing recommendations from the United States and other high-income countries.METHODS A comprehensive search for current HCV testing recommendations from the top quartile of United Nations Human Development Index(HDI) countries(very high HDI) was performed using Google and reviewed from May 1-October 30, 2014 and re-reviewed April 1-October 2, 2017. RESULTS Of the 51 countries identified, 16 had HCV testing recom-mendations from a government body or recommendations issued collaboratively between a government and a medical organization. Of these 16 countries, 15 had HCV testing recommendations that were primarily risk-based and highlight behaviors, exposures, and conditions that are associated with HCV transmission in that region. In addition to risk-based testing, the HCV Guidance Panel(United States) incorporates recommendations for aone-time test for individuals born during 1945-1965(the birth cohort) without prior ascertainment of risk into their guidance. In addition to the United States, six other countries either have an age-based testing recommendation or recommend one-time testing for all adults independent of risk factors typical of the region. CONCLUSION This review affirmed the similarities of the HCV Guidance Panel's guidance with those of recommendations from very high HDI countries.
文摘In this paper, ultrasonic C-scan test of spot welds for stainless steel has been studied. It is concluded that large scanning step length contributes to high testing efficiency, however, the low-resolution C-scan image generated cannot be used to assess spot welding quality reliably. Based on bicubic image interpolation, the C-scan image in low resolution with the large step length 1 000 ~xm is subdivided and reconstructed. By this means, the C-scan image resolution is greatly enhanced and testing results obtained are satisfactory, realizing rapid assessment of spot welds. The results of rapid ultrasonic C-scan test fit the actual metallographic measured value well. Mean value of normal distribution of error statistics is O. 006 67, and the standard deviation is O. 087 11. Rapid ultrasonic C-scan test based on image interpolation is of high accuracy and excellent stability.
文摘The tensile properties of three different carbonfiberreinforced carbon composites (C/C), mat C/C, 2D laminate and 4D C/C, were investigated under the combined influence of temperature and loading rate. From the experiments the following could be concluded: loading rate between 10-1-10 mm/min was valid; the fracture stress of the three kinds of C/C composites increased with increasing temperature in the range from room temperature to 1900, and the initial modulus of 2D laminate C/C composites increased with the increase of temperature up to 2000.
文摘A capsulated microdose 14C-urea breath test (14C-UBT) was developed to detect Helicobacter pylori (HP) infection in 137 patients (54 HP negative and 83 HP positive individuals)to whom a single dose of 3. 7ｘ 104 Bq of 14C-urea in a capsule was given. Samples of exhaled gas were collected at the sib, 10th, 15th. 20th, 25th, 30th, 45th and 60th minute after the administration and the peak value of exhaled 14CO2 was found in the samples collected at the 25th minute. This peak value was taken as the measuring point and directly expressed as Bq/mmol CO2 to develop a new detecting method. Then its results were compared with those of HP culture and histological examination. It was found that the samples collected on the 25th minute showed a sensitivity of 97. 06%, specificity of 95. 12%, positive predictive value of 97. 06% and negative predictive value of 95. 12% respectively when the mean value of 14CO2 in HP negative subjects ±3s on the 25th minute was taken as the critical value. This suggests that the capsule-based microdose 14C-UBT may replace conventional 14C-UBT using a larger dose of (1. 85-3. 7)ｘ 105 Bq for it is non-invasive, safe, rapid, accurate, simple and economic.
基金Sponsored by the National Security Basic Research Program of China (Grant No.61391)the National Natural Science Foundation of China (Grant No.91016029,10902030)
文摘It is important to reveal the performance of carbon/carbon composites subjected to complex loading, which can provide a basis for developing the failure laws of carbon/carbon composites. The uniaxial and biaxial compressive performances of three-dimensional reinforced carbon/carbon composites (3D C/C) were investigated in this paper. The results showed that the compressive strength becomes larger when the loading direction parallels to the z-direction of 3D C/C. The uniaxial compression failure was mainly caused by fracture fiber bundles to form an overall shear fault in the z-direction. The failure mode was delamination of fiber bundle/matrix interface for the x- and y-direction samples. The biaxial compressive failure of x-y direction compressioncompression specimen was caused by the low interlaminar shear strength. In addition,for y-z and z-x direction compression-compression samples,the shear-type failure was formed on the surface of the specimen plumbing the loading direction. Overall,the weak-interface is still a main factor to influent the fracture mechanism of 3D C/C.
