Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In...Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In this study, the chemisorption of sulfur on the surface of deactivated Pd/C was detected by energy dispersive spec-trometer and X-ray photoelectron spectroscopy. Sulfur compounds poison the Pd/C catalyst and increase the forma-tion of azo deposit, reducing the activity of catalyst. We report a mild method to regenerate the Pd/C catalyst: wash the deposit by N,N-dimethylformamide and oxidize the chemisorbed sulfur by hot air. The regenerated Pd/C cata-lyst can be reused at least ten runs with stable activity.展开更多
Human amniotic epithelial cells (HAECs), which exhibit characteristics of embryonic and pluripotent stem cells, could be utilized for cell therapy without legal or ethical problems. Double-transgenic (TG) mice (n=20) ...Human amniotic epithelial cells (HAECs), which exhibit characteristics of embryonic and pluripotent stem cells, could be utilized for cell therapy without legal or ethical problems. Double-transgenic (TG) mice (n=20) and wild-type (WT) mice (n=20) were randomly assigned to two groups, respectively. The transplantation group was treated with HAECs and the control group with PBS. A six-radial arm water maze was used to assess spatial memory. Immunofluorescence was utilized to track HAEC survival. Immunohistochemistry was used to determine octamer-binding protein 4 (oct-4) and nanog expression in the HAECs. High-performance liquid chromatography (HPLC) was used to measure acetylcholine levels in the hippocampus. The density of cholinergic neurons in the basal forebrain and nerve fibers in the hippocampus was measured following acetylcholinesterase staining. Results showed that transplanted HAECs survived for at least eight weeks and migrated to the third ventricle without immune rejection. Graft HAECs also expressed the specific stem cell markers oct-4 and nanog. Compared with the control group, HAEC transplantation significantly ameliorated spatial memory deficits in TG mice, as well as increased acetylcholine levels and the number of hippocampal cholinergic neurites. Intracerebroventricular HAEC transplantation improved spatial memory in double-TG mice, and results suggested that increased acetylcholine levels in the hippocampus, released by surviving cholinergic neurites, were responsible for this improvement.展开更多
基金Supported by the Natural Science Foundation of Zhejiang Provincial （LYI2B03009） and Program for Zhejiang Leading Team of Science and Technology Innovation （2011 R09020-03）.
文摘Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In this study, the chemisorption of sulfur on the surface of deactivated Pd/C was detected by energy dispersive spec-trometer and X-ray photoelectron spectroscopy. Sulfur compounds poison the Pd/C catalyst and increase the forma-tion of azo deposit, reducing the activity of catalyst. We report a mild method to regenerate the Pd/C catalyst: wash the deposit by N,N-dimethylformamide and oxidize the chemisorbed sulfur by hot air. The regenerated Pd/C cata-lyst can be reused at least ten runs with stable activity.
文摘Human amniotic epithelial cells (HAECs), which exhibit characteristics of embryonic and pluripotent stem cells, could be utilized for cell therapy without legal or ethical problems. Double-transgenic (TG) mice (n=20) and wild-type (WT) mice (n=20) were randomly assigned to two groups, respectively. The transplantation group was treated with HAECs and the control group with PBS. A six-radial arm water maze was used to assess spatial memory. Immunofluorescence was utilized to track HAEC survival. Immunohistochemistry was used to determine octamer-binding protein 4 (oct-4) and nanog expression in the HAECs. High-performance liquid chromatography (HPLC) was used to measure acetylcholine levels in the hippocampus. The density of cholinergic neurons in the basal forebrain and nerve fibers in the hippocampus was measured following acetylcholinesterase staining. Results showed that transplanted HAECs survived for at least eight weeks and migrated to the third ventricle without immune rejection. Graft HAECs also expressed the specific stem cell markers oct-4 and nanog. Compared with the control group, HAEC transplantation significantly ameliorated spatial memory deficits in TG mice, as well as increased acetylcholine levels and the number of hippocampal cholinergic neurites. Intracerebroventricular HAEC transplantation improved spatial memory in double-TG mice, and results suggested that increased acetylcholine levels in the hippocampus, released by surviving cholinergic neurites, were responsible for this improvement.
