Objective The causal agent for SARS is considered as a novel coronavirus that has never been described both in human and animals previously. The stability of SARS coronavirus in human specimens and in environments was...Objective The causal agent for SARS is considered as a novel coronavirus that has never been described both in human and animals previously. The stability of SARS coronavirus in human specimens and in environments was studied. Methods Using a SARS coronavirus strain CoV-P9, which was isolated from pharyngeal swab of a probable SARS case in Beijing, its stability in mimic human specimens and in mimic environment including surfaces of commonly used materials or in household conditions, as well as its resistances to temperature and UV irradiation were analyzed. A total of 106 TCID50 viruses were placed in each tested condition, and changes of the viral infectivity in samples after treatments were measured by evaluating cytopathic effect (CPE) in cell line Vero-E6 at 48 h after infectionn. Results The results showed that SARS coronavirus in the testing condition could survive in serum, 1:20 diluted sputum and feces for at least 96 h, whereas it could remain alive in urine for at least 72 h with a low level of infectivity. The survival abilities on the surfaces of eight different materials and in water were quite comparable, revealing reduction of infectivity after 72 to 96 h exposure. Viruses stayed stable at 4℃, at room temperature (20℃) and at 37℃ for at least 2 h without remarkable change in the infectious ability in cells, but were converted to be non-infectious after 90-, 60- and 30-min exposure at 56℃, at 67℃ and at 75℃, respectively. Irradiation of UV for 60 min on the virus in culture medium resulted in the destruction of viral infectivity at an undetectable level. Conclusion The survival ability of SARS coronavirus in human specimens and in environments seems to be relatively strong. Heating and UV irradiation can efficiently eliminate the viral infectivity.展开更多
Background Reserpine is currently used by millions of Chinese hypertensive patients, in spite of the continued concern of its depressogenic effect, even when used in low dose. This study aimed to investigate the assoc...Background Reserpine is currently used by millions of Chinese hypertensive patients, in spite of the continued concern of its depressogenic effect, even when used in low dose. This study aimed to investigate the association between low-dose reserpine use and depression in older Chinese hypertensive patient. Methods In this cross-sectional, case-control study, we recruited patient aged 60 years or over who had regularly taken one or two tables of “compound reserpine and triamterene tablets (CRTTs)” for more than one year (reserpine user) from 26 community health centers located in 10 provinces in China. For each patient who took CRTTs, we selected an age (within five years) and sex matched hypertensive patient who had never taken any drugs containing reserpine (non-reserpine user) as control. Depressive symptoms were evaluated using a Chinese depression scale adapted from the Zung Self-Rating Depression Scale. Demographic, clinical data and laboratory examination results within six months were collected. Results From August 2018 to December 2018, 787 reserpine user and 787 non-reserpine user were recruited. The mean age of all study subjects was 70.3 years, with about equal numbers of males and females. The mean depression score was 40.4 in reserpine users and 40.6 in non-reserpine users (P = 0.7). The majority of study subject had a depression score < 53 (87.6% in reserpine users and 88.2% in non-reserpine users, respectively). There were no significant differences in the prevalence of mild, moderate or severe depression in reserpine users and non-reserpine users. Conclusions There is no association between low-dose reserpine use and depression in older hypertensive patient. The role of reserpine in the treatment and control of hypertension should be reconsidered;and further studies, especially randomized, controlled clinical trials to compare efficacy and safety of reserpine and other widely recommended anti-hypertensive agents are needed.展开更多
To produce the monoclonal antibodies （mAbs） against hygromycin B phosphotransferase （HPT） and to develop immunoassay based on mAbs for biosafety assessment of HPT in genetically modified rice （GM rice）. Methods ...To produce the monoclonal antibodies （mAbs） against hygromycin B phosphotransferase （HPT） and to develop immunoassay based on mAbs for biosafety assessment of HPT in genetically modified rice （GM rice）. Methods BALB/c mice were immunized with purified recombinant 6His. HPT protein, and the conventional hybridoma technology was used to generate the monoclonal hybridoma cells. ELISA and Western blot were used to analyze the specificity of mAbs recognizing HPT and the cross reaction with other proteins. A double-Ab sandwich ELISA method was established to detect HPT expression level in the sck gene-modified rice plants. Results Four hybridomas, named F1,D4-2, D4-4, and D4-5, producing the mAbs against HPT were successfully obtained with the titer of ascetic mAbs ranging from 10×10^-4 to10×10^-5. Identification of subclass showed that all the produced mAbs belonged to IgG1. Western blot showed specific binding reaction between the mAbs to the HPT proteins expressed in the GM rice. A double sandwich ELISA coated with anti-HPT polyclonal antibody was established with mAbs as sandwich antibody, which showed a sensitivity of 30ng/mL and did not crossreact with other proteins. The expression level of HPT in the leaves of sck-transformed lines was detected （80-150ng/mL）. But HPT protein in the grain and seed of GM rice could not be detected using this ELISA assay, Conclusion Anti-HPT mAbs prepared herein have a high specificity and can be used for rapid assay of HPT antigen. The expression level of HPT in the GM rice grain and seed is lower than our ELISA detection limit.展开更多
Rainfall, runoff(surface runoff and interflow) and soil loss were recorded from 2002 to2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground...Rainfall, runoff(surface runoff and interflow) and soil loss were recorded from 2002 to2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground(control check, CK),interplanting with soybean in spring or radish in autumn(I), level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace)(II), and level terraces of orchards with Bahia grass planted on the riser(III). The surface runoff and erosion in treatment II and III during the four years were low despite the occurrence of potentially erosive rains. By contrast, the CK plot had both the highest surface runoff coefficient and the highest sediment yield among all the plots. The surface runoff and soil erosion of the CK plot significantly differed from that of the treatment plots(p < 0.05). Additionally,Significant differences between the interflow of the CK plot and that of the treatment plots was found from April to August(p < 0.05). However, no significant differences between the CK and treatment plots were found from January to March and September to December. The order of the plots in terms of surface runoff coefficients and soil losses was: CK > I > III > II, whereas their order in terms of interflow was II > III > I > CK. The effects of treatment II were excellent, indicating that level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace) can be an excellent practice for soil and water conservation on sloping red soil land. Soil loss in southern China can be reduced through the widespread use of this approach.展开更多
基金This work was supported by the National High-Technology Research and Development Program of China (863 Program) 2003AA208402.
文摘Objective The causal agent for SARS is considered as a novel coronavirus that has never been described both in human and animals previously. The stability of SARS coronavirus in human specimens and in environments was studied. Methods Using a SARS coronavirus strain CoV-P9, which was isolated from pharyngeal swab of a probable SARS case in Beijing, its stability in mimic human specimens and in mimic environment including surfaces of commonly used materials or in household conditions, as well as its resistances to temperature and UV irradiation were analyzed. A total of 106 TCID50 viruses were placed in each tested condition, and changes of the viral infectivity in samples after treatments were measured by evaluating cytopathic effect (CPE) in cell line Vero-E6 at 48 h after infectionn. Results The results showed that SARS coronavirus in the testing condition could survive in serum, 1:20 diluted sputum and feces for at least 96 h, whereas it could remain alive in urine for at least 72 h with a low level of infectivity. The survival abilities on the surfaces of eight different materials and in water were quite comparable, revealing reduction of infectivity after 72 to 96 h exposure. Viruses stayed stable at 4℃, at room temperature (20℃) and at 37℃ for at least 2 h without remarkable change in the infectious ability in cells, but were converted to be non-infectious after 90-, 60- and 30-min exposure at 56℃, at 67℃ and at 75℃, respectively. Irradiation of UV for 60 min on the virus in culture medium resulted in the destruction of viral infectivity at an undetectable level. Conclusion The survival ability of SARS coronavirus in human specimens and in environments seems to be relatively strong. Heating and UV irradiation can efficiently eliminate the viral infectivity.
文摘Background Reserpine is currently used by millions of Chinese hypertensive patients, in spite of the continued concern of its depressogenic effect, even when used in low dose. This study aimed to investigate the association between low-dose reserpine use and depression in older Chinese hypertensive patient. Methods In this cross-sectional, case-control study, we recruited patient aged 60 years or over who had regularly taken one or two tables of “compound reserpine and triamterene tablets (CRTTs)” for more than one year (reserpine user) from 26 community health centers located in 10 provinces in China. For each patient who took CRTTs, we selected an age (within five years) and sex matched hypertensive patient who had never taken any drugs containing reserpine (non-reserpine user) as control. Depressive symptoms were evaluated using a Chinese depression scale adapted from the Zung Self-Rating Depression Scale. Demographic, clinical data and laboratory examination results within six months were collected. Results From August 2018 to December 2018, 787 reserpine user and 787 non-reserpine user were recruited. The mean age of all study subjects was 70.3 years, with about equal numbers of males and females. The mean depression score was 40.4 in reserpine users and 40.6 in non-reserpine users (P = 0.7). The majority of study subject had a depression score < 53 (87.6% in reserpine users and 88.2% in non-reserpine users, respectively). There were no significant differences in the prevalence of mild, moderate or severe depression in reserpine users and non-reserpine users. Conclusions There is no association between low-dose reserpine use and depression in older hypertensive patient. The role of reserpine in the treatment and control of hypertension should be reconsidered;and further studies, especially randomized, controlled clinical trials to compare efficacy and safety of reserpine and other widely recommended anti-hypertensive agents are needed.
基金This work was supported by 973 National Fundamental Science Program Funds (2001CB109007 and 2001CB10901)and 863 National High-Tech Program Funds (2004AA212221 and 2002AA212041).
文摘To produce the monoclonal antibodies （mAbs） against hygromycin B phosphotransferase （HPT） and to develop immunoassay based on mAbs for biosafety assessment of HPT in genetically modified rice （GM rice）. Methods BALB/c mice were immunized with purified recombinant 6His. HPT protein, and the conventional hybridoma technology was used to generate the monoclonal hybridoma cells. ELISA and Western blot were used to analyze the specificity of mAbs recognizing HPT and the cross reaction with other proteins. A double-Ab sandwich ELISA method was established to detect HPT expression level in the sck gene-modified rice plants. Results Four hybridomas, named F1,D4-2, D4-4, and D4-5, producing the mAbs against HPT were successfully obtained with the titer of ascetic mAbs ranging from 10×10^-4 to10×10^-5. Identification of subclass showed that all the produced mAbs belonged to IgG1. Western blot showed specific binding reaction between the mAbs to the HPT proteins expressed in the GM rice. A double sandwich ELISA coated with anti-HPT polyclonal antibody was established with mAbs as sandwich antibody, which showed a sensitivity of 30ng/mL and did not crossreact with other proteins. The expression level of HPT in the leaves of sck-transformed lines was detected （80-150ng/mL）. But HPT protein in the grain and seed of GM rice could not be detected using this ELISA assay, Conclusion Anti-HPT mAbs prepared herein have a high specificity and can be used for rapid assay of HPT antigen. The expression level of HPT in the GM rice grain and seed is lower than our ELISA detection limit.
基金funded by the National Science and Technique Sustentation Project (Grant No. 2012BAJ25B01)
文摘Rainfall, runoff(surface runoff and interflow) and soil loss were recorded from 2002 to2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground(control check, CK),interplanting with soybean in spring or radish in autumn(I), level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace)(II), and level terraces of orchards with Bahia grass planted on the riser(III). The surface runoff and erosion in treatment II and III during the four years were low despite the occurrence of potentially erosive rains. By contrast, the CK plot had both the highest surface runoff coefficient and the highest sediment yield among all the plots. The surface runoff and soil erosion of the CK plot significantly differed from that of the treatment plots(p < 0.05). Additionally,Significant differences between the interflow of the CK plot and that of the treatment plots was found from April to August(p < 0.05). However, no significant differences between the CK and treatment plots were found from January to March and September to December. The order of the plots in terms of surface runoff coefficients and soil losses was: CK > I > III > II, whereas their order in terms of interflow was II > III > I > CK. The effects of treatment II were excellent, indicating that level terrace(i.e., grass planted on the riser and bunds built at the edge of a bench terrace) can be an excellent practice for soil and water conservation on sloping red soil land. Soil loss in southern China can be reduced through the widespread use of this approach.
