Scopolamine is a pharmaceutically important tropane alkaloid extensively used as an anticholinergic agent.Here,we report the simultaneous introduction and overexpression of genes encoding the rate-limiting upstream en...Scopolamine is a pharmaceutically important tropane alkaloid extensively used as an anticholinergic agent.Here,we report the simultaneous introduction and overexpression of genes encoding the rate-limiting upstream enzyme pu-trescine N-methyltransferase(PMT)and the downstream enzyme hyoscyamine6β-hydroxylase(H6H)of scopolamine biosynthesis in transgenic henbane(Hyoscyamus niger)hairy root cultures.Transgenic hairy root lines expressing both pmt and h6h produced significantly higher(P<0.05)levels of scopolamine compared with the wild-type and transgenic lines har-boring a single gene(pmt or h6h).The best line(T 3 )produced411mg/liter scopolamine,which was over nine times more than that in the wild type(43mg/liter)and more than twice the amount in the highest scopolamine-producing h6h single-gene transgenic line H 11 (184mg/liter).To our knowledge,this is the highest scopolamine content achieved through genetic engi-neering of a plant.We conclude that transgenic plants harboring both pmt and h6h possessed an increased flux in the tropane alkaloid biosynthetic pathway that enhanced scopolamine yield,which was more efficient than plants harboring only one of the two genes.It seems that the pulling force of the downstream enzyme(the faucet enzyme)H6H plays a more important role in stimulating scopolamine accumulation in H.niger whereas the functioning of the upstream enzyme PMT is increased propor-tionally.This study provides an effective approach for large-scale commercial production of scopolamine by using hairy root culture systems as bioreactors.展开更多
Greenhouse-gas (GHG) emissions in China have aroused much interest, and not least in recent evidence of their reduction. Our intent is to place that reduction in a larger context, that of the process of industrializat...Greenhouse-gas (GHG) emissions in China have aroused much interest, and not least in recent evidence of their reduction. Our intent is to place that reduction in a larger context, that of the process of industrialization. A lengthy time perspective is combined with a cross-sectional approach-China plus five other countries-and addressed through two general models. The findings are salutary. First, they suggest that a diversified economic structure is consistent with diminished intensity in energy use. Secondly, and the obverse of the first, they imply that a diversified energy structure promotes reductions in CO2 emissions. Finally, one is led inevitably to the conclusion that, together, the findings point to a path for countries to transform their economies while at the same time undertaking to drastically moderate their energy use, switching from a pattern of heavy carbon emissions to one in which lighter carbon emissions prevail. The implications of such findings for environmental management are enormous.展开更多
目的:探究肥胖、超重与正常体型老年高血压患者之间的一般临床资料变化及血清瘦素浓度差异,通过相关影响因素预测老年高血压血清瘦素浓度。方法:收治老年高血压患者110例,肥胖35例,超重37例,正常体型38例,收集一般临床资料并测定血清瘦...目的:探究肥胖、超重与正常体型老年高血压患者之间的一般临床资料变化及血清瘦素浓度差异,通过相关影响因素预测老年高血压血清瘦素浓度。方法:收治老年高血压患者110例,肥胖35例,超重37例,正常体型38例,收集一般临床资料并测定血清瘦素浓度,进行组间比较;运用多重线性回归选择相关因素预测血清瘦素水平。结果:在不同体型组的老年高血压患者中,体脂率、体重指数(BMI)、腰臀比(WHR)、血清尿酸(UA)、同型半胱氨酸(Hcy)、24 h平均收缩压(SBP)、血清瘦素(Leptin)差异有统计学意义(P<0.05或P<0.01)。运用多重线性回归,根据24 h SBP、BMI、UA水平预测血清瘦素浓度的回归模型有统计学意义,F(3,105)=150.300(P<0.001)。结论:老年高血压患者瘦素水平与BMI、24 h SBP、UA水平相关,这三者可对老年高血压患者血清瘦素浓度进行预测。展开更多
For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid ec...For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid economic growth, rising living standard, widespread environmental degradation, limited oil reserves and uneven resources distribution. Industrialization and urbanization since the early 1980s have imposed structural constraints on its traditional coal-based energy supply model. Eventually, China became a net oil-importer in 1993 when ten million tons of crude oil and petroleum products from abroad fed into the local economies of the coastal areas. Such a change meant that energy security has become an increasingly sensitive issue to the central government of China. This paper argues that China could benefit from a more open energy supply by striking to a balance of both domestic and international sources, rather than the traditional mode emphasized on a highly self-sufficiency rate.展开更多
On the basis of CMAC-PDM (Pattern Discrimination Model) , a novel algorithmof CMAC for monitoring machine degradation is proposed in this paper. The output of CMAC with thenovel algorithm represents the state of a mac...On the basis of CMAC-PDM (Pattern Discrimination Model) , a novel algorithmof CMAC for monitoring machine degradation is proposed in this paper. The output of CMAC with thenovel algorithm represents the state of a machine and PDM is not needed. The principle was explainedby analyzing the modified mapping process of CMAC. The novel CMAC is applied to a tool conditionmonitoring system and two methodologies (novel CMAC and CMAC-PDM) are compared. The results provethat the novel algorithm is feasible and its computational complexity is reduced significantly.展开更多
AIM: To determine the expressions of cysteinyl leukotriene receptors, CysLT, and CysLT2 , in airway eosinophilic inflammation of OVA-induced asthmatic mice and the modulation by montelukast, a CysLT1 receptor antagoni...AIM: To determine the expressions of cysteinyl leukotriene receptors, CysLT, and CysLT2 , in airway eosinophilic inflammation of OVA-induced asthmatic mice and the modulation by montelukast, a CysLT1 receptor antagonist. METHODS: Asthma model was induced by chronic exposure to ovalbumin (OVA) in C57BL/6 mice. The eosinophils展开更多
文摘Scopolamine is a pharmaceutically important tropane alkaloid extensively used as an anticholinergic agent.Here,we report the simultaneous introduction and overexpression of genes encoding the rate-limiting upstream enzyme pu-trescine N-methyltransferase(PMT)and the downstream enzyme hyoscyamine6β-hydroxylase(H6H)of scopolamine biosynthesis in transgenic henbane(Hyoscyamus niger)hairy root cultures.Transgenic hairy root lines expressing both pmt and h6h produced significantly higher(P<0.05)levels of scopolamine compared with the wild-type and transgenic lines har-boring a single gene(pmt or h6h).The best line(T 3 )produced411mg/liter scopolamine,which was over nine times more than that in the wild type(43mg/liter)and more than twice the amount in the highest scopolamine-producing h6h single-gene transgenic line H 11 (184mg/liter).To our knowledge,this is the highest scopolamine content achieved through genetic engi-neering of a plant.We conclude that transgenic plants harboring both pmt and h6h possessed an increased flux in the tropane alkaloid biosynthetic pathway that enhanced scopolamine yield,which was more efficient than plants harboring only one of the two genes.It seems that the pulling force of the downstream enzyme(the faucet enzyme)H6H plays a more important role in stimulating scopolamine accumulation in H.niger whereas the functioning of the upstream enzyme PMT is increased propor-tionally.This study provides an effective approach for large-scale commercial production of scopolamine by using hairy root culture systems as bioreactors.
基金National Basic Research Priorities Programme of China No.2002CB412507+1 种基金 Research Program of the Ministry of Science and Technology of China No.973-2002CB412507
文摘Greenhouse-gas (GHG) emissions in China have aroused much interest, and not least in recent evidence of their reduction. Our intent is to place that reduction in a larger context, that of the process of industrialization. A lengthy time perspective is combined with a cross-sectional approach-China plus five other countries-and addressed through two general models. The findings are salutary. First, they suggest that a diversified economic structure is consistent with diminished intensity in energy use. Secondly, and the obverse of the first, they imply that a diversified energy structure promotes reductions in CO2 emissions. Finally, one is led inevitably to the conclusion that, together, the findings point to a path for countries to transform their economies while at the same time undertaking to drastically moderate their energy use, switching from a pattern of heavy carbon emissions to one in which lighter carbon emissions prevail. The implications of such findings for environmental management are enormous.
文摘目的:探究肥胖、超重与正常体型老年高血压患者之间的一般临床资料变化及血清瘦素浓度差异,通过相关影响因素预测老年高血压血清瘦素浓度。方法:收治老年高血压患者110例,肥胖35例,超重37例,正常体型38例,收集一般临床资料并测定血清瘦素浓度,进行组间比较;运用多重线性回归选择相关因素预测血清瘦素水平。结果:在不同体型组的老年高血压患者中,体脂率、体重指数(BMI)、腰臀比(WHR)、血清尿酸(UA)、同型半胱氨酸(Hcy)、24 h平均收缩压(SBP)、血清瘦素(Leptin)差异有统计学意义(P<0.05或P<0.01)。运用多重线性回归,根据24 h SBP、BMI、UA水平预测血清瘦素浓度的回归模型有统计学意义,F(3,105)=150.300(P<0.001)。结论:老年高血压患者瘦素水平与BMI、24 h SBP、UA水平相关,这三者可对老年高血压患者血清瘦素浓度进行预测。
基金Undertheauspicesof the National Natural Science FoundationofChina(No.90210037)
文摘For many years, China has made great strides in constructing a sizeable and stable energy supply system rooted mainly in domestic coal supply. That system, however, is subject to immense strain as a result of rapid economic growth, rising living standard, widespread environmental degradation, limited oil reserves and uneven resources distribution. Industrialization and urbanization since the early 1980s have imposed structural constraints on its traditional coal-based energy supply model. Eventually, China became a net oil-importer in 1993 when ten million tons of crude oil and petroleum products from abroad fed into the local economies of the coastal areas. Such a change meant that energy security has become an increasingly sensitive issue to the central government of China. This paper argues that China could benefit from a more open energy supply by striking to a balance of both domestic and international sources, rather than the traditional mode emphasized on a highly self-sufficiency rate.
文摘On the basis of CMAC-PDM (Pattern Discrimination Model) , a novel algorithmof CMAC for monitoring machine degradation is proposed in this paper. The output of CMAC with thenovel algorithm represents the state of a machine and PDM is not needed. The principle was explainedby analyzing the modified mapping process of CMAC. The novel CMAC is applied to a tool conditionmonitoring system and two methodologies (novel CMAC and CMAC-PDM) are compared. The results provethat the novel algorithm is feasible and its computational complexity is reduced significantly.
文摘AIM: To determine the expressions of cysteinyl leukotriene receptors, CysLT, and CysLT2 , in airway eosinophilic inflammation of OVA-induced asthmatic mice and the modulation by montelukast, a CysLT1 receptor antagonist. METHODS: Asthma model was induced by chronic exposure to ovalbumin (OVA) in C57BL/6 mice. The eosinophils
