The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intens...The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intensities of 10 10 ～10 11 W/cm 2 indicate a multiphoton ionization and dissociation (MPID) process, in which C +, C 2H x +, C 3H x +, C 4H x + and C 6H 6 + are main products. While at 1064 nm laser of similar intensities, the domain ion is C 4+ which is produced from Coulomb explosion. The longer wavelength facilities the energy absorption rate during inverse bremsstrahlung, which leads to the resulting wavelength dependence of the multicharged atomic ions.展开更多
前β1-高密度脂蛋白(high density lipoprotein,HDL)是HDL的一种亚类,存在于血浆中,具有颗粒小、密度高、前β-脂蛋白迁移率等特性。前β1-HDL不仅与HDL成熟过程有关,而且在外周细胞胆固醇外流、酯化以及转运中起着重要作用。高前β1-HD...前β1-高密度脂蛋白(high density lipoprotein,HDL)是HDL的一种亚类,存在于血浆中,具有颗粒小、密度高、前β-脂蛋白迁移率等特性。前β1-HDL不仅与HDL成熟过程有关,而且在外周细胞胆固醇外流、酯化以及转运中起着重要作用。高前β1-HDL水平不仅与冠心病(coronary heart disease,CHD)、心肌梗死(myocardial infarction,MI)及颈动脉内膜中层增厚等疾病相关,还可反映胆固醇的逆向转运(reverse cholesterol transport,RCT)过程中胆固醇外排或酯化功能障碍,可评估外排效率。文中主要对前β1-HDL结构和代谢及其与CHD的关系作一综述。展开更多
肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidin...肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidine 5'-diphosphocholine,COD-胆碱)和磷脂酰乙醇胺甲基化途径参与了PC的生物合成。文中就PC的合成和转运对VLDL分泌功能的影响进行综述。展开更多
文摘The photoionization of seeded benzene beam by 25 ns laser pulse at wavelengths of 266, 355 and 1064 nm has been studied by the time of flight mass spectrometry. The observed mass spectra at 266 nm and 355 nm at intensities of 10 10 ～10 11 W/cm 2 indicate a multiphoton ionization and dissociation (MPID) process, in which C +, C 2H x +, C 3H x +, C 4H x + and C 6H 6 + are main products. While at 1064 nm laser of similar intensities, the domain ion is C 4+ which is produced from Coulomb explosion. The longer wavelength facilities the energy absorption rate during inverse bremsstrahlung, which leads to the resulting wavelength dependence of the multicharged atomic ions.
文摘肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidine 5'-diphosphocholine,COD-胆碱)和磷脂酰乙醇胺甲基化途径参与了PC的生物合成。文中就PC的合成和转运对VLDL分泌功能的影响进行综述。
