天然的丝状真菌是我国重要的微生物资源,能产生大量有益的初生、次生代谢产物,其代谢受到各类调控因子的调控。天鹅绒(Velvet)蛋白家族是真菌中最独特且高度保守的一类特殊调控蛋白,可调控真菌的生长、分化和次生代谢物的生物合成。该...天然的丝状真菌是我国重要的微生物资源,能产生大量有益的初生、次生代谢产物,其代谢受到各类调控因子的调控。天鹅绒(Velvet)蛋白家族是真菌中最独特且高度保守的一类特殊调控蛋白,可调控真菌的生长、分化和次生代谢物的生物合成。该文结合国内外的研究进展综述Velvet蛋白家族Velvet A(VeA)、Velvet like B(VelB)在真菌中的结构及其蛋白复合物对生长发育和次生代谢的调控作用,可为进一步探索Velvet蛋白家族调控真菌次生代谢物的生物合成通路、激活沉默基因簇、挖掘新的化合物提供参考。展开更多
基于需求工程的基本概念和研究内容,介绍了两种需求工程支持工具：Visio for Enterprise Architects（VEA）和魔力工作室（MSS）,并针对各自的特点和功能以及作为开发工具时的便利性和有效性进行比较,显示出使用MSS进行需求分析的优势...基于需求工程的基本概念和研究内容,介绍了两种需求工程支持工具：Visio for Enterprise Architects（VEA）和魔力工作室（MSS）,并针对各自的特点和功能以及作为开发工具时的便利性和有效性进行比较,显示出使用MSS进行需求分析的优势所在。展开更多
Water and sediment samples were taken from selected irrigation dams located at Tono and Vea in the Upper East Region of Ghana and analyzed for organic pesticides using gas chromatography. Sixteen organic residues were...Water and sediment samples were taken from selected irrigation dams located at Tono and Vea in the Upper East Region of Ghana and analyzed for organic pesticides using gas chromatography. Sixteen organic residues were identified of which thirteen had at least some trace concentrations ranging from 0.001 to 25.4 μg/L. It was found in the laboratory that the concentrations of DDT, BHC and heptachlor were above the upper limited recommended by WHO and the concentrations of DDT in both reservoirs were higher than 20 times the recommended limits. High concentrations of DDT were found in the water samples while the other two residues were identified in the sediments. The high DDT concentration in water was due to 1) the initial amount of DDT applied and the period in the reservoirs, 2) a half-life of 350 days suggested that much of the DDT originally used was not destroyed if applied less than this period, 3) its low solubility in water did not allow for dissolution and subsequent dispersal in water;4) the indiscriminate uses of DDT for fishing as confirmed by the local people The high DDT level suggested that the water is not safe for many aquatic organisms and even humans. Generally the levels of these organic residues suggested that the dams have been polluted due to human activities such as farming and the unorthodox method of fishing. Therefore, steps should be taken to reduce the levels of DDT concentrations to preserve the aquatic life in the dams.展开更多
文摘天然的丝状真菌是我国重要的微生物资源,能产生大量有益的初生、次生代谢产物,其代谢受到各类调控因子的调控。天鹅绒(Velvet)蛋白家族是真菌中最独特且高度保守的一类特殊调控蛋白,可调控真菌的生长、分化和次生代谢物的生物合成。该文结合国内外的研究进展综述Velvet蛋白家族Velvet A(VeA)、Velvet like B(VelB)在真菌中的结构及其蛋白复合物对生长发育和次生代谢的调控作用,可为进一步探索Velvet蛋白家族调控真菌次生代谢物的生物合成通路、激活沉默基因簇、挖掘新的化合物提供参考。
文摘Water and sediment samples were taken from selected irrigation dams located at Tono and Vea in the Upper East Region of Ghana and analyzed for organic pesticides using gas chromatography. Sixteen organic residues were identified of which thirteen had at least some trace concentrations ranging from 0.001 to 25.4 μg/L. It was found in the laboratory that the concentrations of DDT, BHC and heptachlor were above the upper limited recommended by WHO and the concentrations of DDT in both reservoirs were higher than 20 times the recommended limits. High concentrations of DDT were found in the water samples while the other two residues were identified in the sediments. The high DDT concentration in water was due to 1) the initial amount of DDT applied and the period in the reservoirs, 2) a half-life of 350 days suggested that much of the DDT originally used was not destroyed if applied less than this period, 3) its low solubility in water did not allow for dissolution and subsequent dispersal in water;4) the indiscriminate uses of DDT for fishing as confirmed by the local people The high DDT level suggested that the water is not safe for many aquatic organisms and even humans. Generally the levels of these organic residues suggested that the dams have been polluted due to human activities such as farming and the unorthodox method of fishing. Therefore, steps should be taken to reduce the levels of DDT concentrations to preserve the aquatic life in the dams.
