AIM: To investigate whether TL-10-transduced dendritic cells (DCs) could induce tolerogenicity and prolong allograft survival in rat intestinal transplantation.METHODS: Spleen-derived DCs were prepared and genetically...AIM: To investigate whether TL-10-transduced dendritic cells (DCs) could induce tolerogenicity and prolong allograft survival in rat intestinal transplantation.METHODS: Spleen-derived DCs were prepared and genetically modified by hTL-10 gene. The level of IL-10 expression was quantitated by ELTSA. DC function was assessed by MTT in mixed leukocyte reaction. Allogeneic T-cell apoptosis was examined by flow cytometric analysis. Seven days before heterotopic intestinal transplantation, 2x106 donor-derived IL-10-DC were injected intravenously, then transplantation was performed between SD donor and Wistar recipient.RESULTS: Compared with untransduced DC, IL-10-DC could suppress allogeneic mixed leukocyte reaction (MLR). The inhibitory effect was the most striking with the stimulator/effector (S/F) ratio of 1:10. The inhibition rate was 33.25 %,41.19 % (P<0.01) and 22.92 % with the S/E ratio of 1:1,1:10 and 1:50 respectively. At 48 hours and 72 hours by flow cytometry counting, apoptotic T cells responded to IL-10-DC in MLR were 13.8 % and 30.1%, while untransduced group did not undergo significant apoptosis (P<0.05). IL-10-DC pretreated recipients had a moderate survival prolongation with a mean allograft survival of 19.8 days (P<0.01),compared with 7.3±2.4 days in control group and 8.3±2.9days in untransduced DC group. Rejection occurred in the control group within three days. The difference between untreated DC group and control group was not significant.CONCLUSION: IL-10-DC can induce allogenic T-cell hyporesponsiveness in vitro and apoptosis may be involved in it. IL-10-DC pretreatment can prolong intestinal allograft survival in the recipient.展开更多
Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyri...Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyridine. A plausible mechanism was hypothesized.展开更多
The growth of single-wall carbon nanotube from graphite layers is studied by tight binding molecular dynamics simulation. Given temperature of 2500 K or 3500 K and an interval of 0.25 nm for the two layers of graphite...The growth of single-wall carbon nanotube from graphite layers is studied by tight binding molecular dynamics simulation. Given temperature of 2500 K or 3500 K and an interval of 0.25 nm for the two layers of graphite, a single-wall carbon nanotube with a zigzag shell will be produced. On the other conditions the carbon nanotube cannot grow or grows with too many defects. All carbon nanotube ends have pentagons which play an important role during the tube ends closing.展开更多
The growth of entrepreneurship in China has been phenomenal since the open-door policyin 1978. Small- and medium-sized enterprises (SMEs) have increasingly played an importantrole in the Chinese economy, accounting fo...The growth of entrepreneurship in China has been phenomenal since the open-door policyin 1978. Small- and medium-sized enterprises (SMEs) have increasingly played an importantrole in the Chinese economy, accounting for about 50 percent of the total GDP in 2001.Nonetheless, a few studies have examined what counts for such rapid growth ofentrepreneurship in China. This study focuses on identifying environmental factors relatedto the success and failure of entrepreneurship in China. Based on a survey of 117 SMEexecutives in Sichuan province, the survey results show that positive social acceptance,risk-taking attitudes and infrastructure adequacy were perceived as most facilitating factors,while market development and exploitation, and adopting low cost strategy were successfactors. The results also reveal that lack of capital and over-competition within the industrywas the key reasons for SME failures.展开更多
文摘AIM: To investigate whether TL-10-transduced dendritic cells (DCs) could induce tolerogenicity and prolong allograft survival in rat intestinal transplantation.METHODS: Spleen-derived DCs were prepared and genetically modified by hTL-10 gene. The level of IL-10 expression was quantitated by ELTSA. DC function was assessed by MTT in mixed leukocyte reaction. Allogeneic T-cell apoptosis was examined by flow cytometric analysis. Seven days before heterotopic intestinal transplantation, 2x106 donor-derived IL-10-DC were injected intravenously, then transplantation was performed between SD donor and Wistar recipient.RESULTS: Compared with untransduced DC, IL-10-DC could suppress allogeneic mixed leukocyte reaction (MLR). The inhibitory effect was the most striking with the stimulator/effector (S/F) ratio of 1:10. The inhibition rate was 33.25 %,41.19 % (P<0.01) and 22.92 % with the S/E ratio of 1:1,1:10 and 1:50 respectively. At 48 hours and 72 hours by flow cytometry counting, apoptotic T cells responded to IL-10-DC in MLR were 13.8 % and 30.1%, while untransduced group did not undergo significant apoptosis (P<0.05). IL-10-DC pretreated recipients had a moderate survival prolongation with a mean allograft survival of 19.8 days (P<0.01),compared with 7.3±2.4 days in control group and 8.3±2.9days in untransduced DC group. Rejection occurred in the control group within three days. The difference between untreated DC group and control group was not significant.CONCLUSION: IL-10-DC can induce allogenic T-cell hyporesponsiveness in vitro and apoptosis may be involved in it. IL-10-DC pretreatment can prolong intestinal allograft survival in the recipient.
文摘Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyridine. A plausible mechanism was hypothesized.
文摘The growth of single-wall carbon nanotube from graphite layers is studied by tight binding molecular dynamics simulation. Given temperature of 2500 K or 3500 K and an interval of 0.25 nm for the two layers of graphite, a single-wall carbon nanotube with a zigzag shell will be produced. On the other conditions the carbon nanotube cannot grow or grows with too many defects. All carbon nanotube ends have pentagons which play an important role during the tube ends closing.
文摘The growth of entrepreneurship in China has been phenomenal since the open-door policyin 1978. Small- and medium-sized enterprises (SMEs) have increasingly played an importantrole in the Chinese economy, accounting for about 50 percent of the total GDP in 2001.Nonetheless, a few studies have examined what counts for such rapid growth ofentrepreneurship in China. This study focuses on identifying environmental factors relatedto the success and failure of entrepreneurship in China. Based on a survey of 117 SMEexecutives in Sichuan province, the survey results show that positive social acceptance,risk-taking attitudes and infrastructure adequacy were perceived as most facilitating factors,while market development and exploitation, and adopting low cost strategy were successfactors. The results also reveal that lack of capital and over-competition within the industrywas the key reasons for SME failures.
