多巴胺（ DA）作为一种重要的儿茶酚胺类神经递质，经中脑腹侧被盖核区投射到前额叶皮质、海马、纹状体、伏隔核、杏仁核、中脑、下丘脑、延髓等部位的多巴胺受体（ DAR），主要参与情感思维、运动功能以及认知活动，也参与突触可塑性...多巴胺（ DA）作为一种重要的儿茶酚胺类神经递质，经中脑腹侧被盖核区投射到前额叶皮质、海马、纹状体、伏隔核、杏仁核、中脑、下丘脑、延髓等部位的多巴胺受体（ DAR），主要参与情感思维、运动功能以及认知活动，也参与突触可塑性的调控。广泛分布于各个脑区的 DAR 属于 G 蛋白偶联受体（ GPCR）中的重要一员，根据其药理学和生化特性不同，可以分为D1样受体和D2样受体两大类，其中前者包括D1和D5受体2种亚型，后者受体包括D2、D3和D43种亚型。近几年研究发现DAR与中枢神经系统疾病如阿尔茨海默病（ AD）关系密切，已经成为预防和治疗AD的重要靶点，然而，DAR的各个亚型在AD发病机制中的作用还不清楚，本文就DAR各个亚型的分布、信号传导及其与 AD 的发病机制的关系进行综述。展开更多
High-resolution X-ray diffraction has been employed to investigate the diffuse scattering in a （0001） oriented GaN epitaxial film grown on sapphire substrate. The analysis reveals that defect clusters are present in...High-resolution X-ray diffraction has been employed to investigate the diffuse scattering in a （0001） oriented GaN epitaxial film grown on sapphire substrate. The analysis reveals that defect clusters are present in GaN films and their concentration increases as the density of threading dislocations increases. Meanwhile, the mean radius of these defect clus- ters shows a reverse tendency. This result is explained by the effect of clusters preferentially forming around dislocations, which act as effective sinks for the segregation of point defects. The electric mobility is found to decrease as the cluster concentration increases.展开更多
文摘多巴胺（ DA）作为一种重要的儿茶酚胺类神经递质，经中脑腹侧被盖核区投射到前额叶皮质、海马、纹状体、伏隔核、杏仁核、中脑、下丘脑、延髓等部位的多巴胺受体（ DAR），主要参与情感思维、运动功能以及认知活动，也参与突触可塑性的调控。广泛分布于各个脑区的 DAR 属于 G 蛋白偶联受体（ GPCR）中的重要一员，根据其药理学和生化特性不同，可以分为D1样受体和D2样受体两大类，其中前者包括D1和D5受体2种亚型，后者受体包括D2、D3和D43种亚型。近几年研究发现DAR与中枢神经系统疾病如阿尔茨海默病（ AD）关系密切，已经成为预防和治疗AD的重要靶点，然而，DAR的各个亚型在AD发病机制中的作用还不清楚，本文就DAR各个亚型的分布、信号传导及其与 AD 的发病机制的关系进行综述。
文摘High-resolution X-ray diffraction has been employed to investigate the diffuse scattering in a （0001） oriented GaN epitaxial film grown on sapphire substrate. The analysis reveals that defect clusters are present in GaN films and their concentration increases as the density of threading dislocations increases. Meanwhile, the mean radius of these defect clus- ters shows a reverse tendency. This result is explained by the effect of clusters preferentially forming around dislocations, which act as effective sinks for the segregation of point defects. The electric mobility is found to decrease as the cluster concentration increases.
