AIM: To compare the preservation of non-heart- beating donor (NHBD) livers in cold histidine-trytophan- ketoglutarate (HTK) solution and extracorporeal liver perfusion (ECLP). METHODS: Livers harvested from health pig...AIM: To compare the preservation of non-heart- beating donor (NHBD) livers in cold histidine-trytophan- ketoglutarate (HTK) solution and extracorporeal liver perfusion (ECLP). METHODS: Livers harvested from health pigs were stored for 10 h in cold HTK solution (group A, n = 4) or perfused with oxygenated autologous blood at body temperature (group B, n = 4). Both groups were then tested on the circuit for 4 h. Bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of extracorporeal livers were tested in each group. Liver tissues from each group were examined at the end of reperfusion. RESULTS: At 1, 2, 3 and 4 h after reperfusion, bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of livers in group A were statistically different from those in group B (P < 0.05 or P < 0.01). CONCLUSION: ECLP is better than HTK solution to preserve NHBD livers. ECLP can assess the graft viabilitybefore liver transplantation.展开更多
BACKGROUND： Studies have shown that scorpion venom heat-resistant protein （SVHRP） exhibits protective effects on primary cultured hippocampal neurons. OBJECTIVE： To determine the effects of SVHRP on astrocyte acti...BACKGROUND： Studies have shown that scorpion venom heat-resistant protein （SVHRP） exhibits protective effects on primary cultured hippocampal neurons. OBJECTIVE： To determine the effects of SVHRP on astrocyte activity and synaptic density in the hippocampus induced by amyloid β peptide 1-40 （Aβ1-40） neurotoxicity. DESIGN, TIME AND SETTING： The randomized, controlled, animal experiment was performed at the Central Laboratory, the Laboratory of Human Anatomy, and the Laboratory of Physiology, in Dalian Medical University between March 2006 and June 2008. MATERIALS： Aβ1-40 was provided by Biosource, USA; SVHRP was a patented biological product of Dalian Medical University （No. ZL01 1 06166.9）. METHODS： A total of 27 healthy, 2-month-old, male SD rats were randomly assigned to 3 groups： control, Aβ, and SVHRP, with 9 rats in each group. Alzheimer＇s disease was simulated with 10 μg Aβ1-40 bilaterally injected into the hippocampus of the Aβ and SVHRP groups. The control group was injected with 2 μL 0.05% trifluoroacetic acid. One day following model establishment, the SVHRP group received an intraperitoneal injection of 2 μg/100 g SVHRP, while the control group and Aβ group received 0.5 mL/100 g tri-distilled water, once per day, for 10 consecutive days. MAIN OUTCOME MEASURES： At 16 days following model establishment, synaptophysin （p38） expression in CA1-CA4 regions of the rat hippocampus was determined by immunohistochemistry. Glial fibrillary acidic protein （GFAP） expression surrounding the hippocampal Aβ1-40 injected area was also detected. At 11 days following model establishment, escape latency, swimming time, and distance to target quadrant were measured using the Morris water maze. RESULTS： Compared with the control group, the Aβ group exhibited notably reduced p38 expression （P 〈 0.05） and notably increased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was prolonged （P 〈 0.05）, and swimming time and distance to the target quadrant were shortened in the Aβ group. Compared with the Aβ group, the SVHRP group exhibited notably increased p38 expression （P 〈 0.05） and notably decreased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was significantly reduced （P 〈 0.05）, and swimming time and distance to the target quadrant were significantly prolonged. CONCLUSION： SVHRP inhibited exogenous Aβ1-40-induced astrocyte activation and synaptic density decline in the rat hippocampus. Place navigation and spatial searching results showed that SVHRP blocked Aβ1-40-induced impaired learning and memory.展开更多
The selective hydrogenation of propyne to propylene has attracted great attention in chemical industry for removing trace amount of propyne for producing polymer-grade propylene. As the state-of-the-art catalyst, Pd s...The selective hydrogenation of propyne to propylene has attracted great attention in chemical industry for removing trace amount of propyne for producing polymer-grade propylene. As the state-of-the-art catalyst, Pd suffers from the disadvantage of poor propylene selectivity due to the over-hydrogenation of propylene to propane. We here demonstrate that Pd nanocubes (NCs) coated by zeolitic imidazolate frameworks (i.e., Pd NCs@ZIF-8) can serve as highly active and selective catalysts for propyne selective hydrogenation (PSH). Benefitting from the unique properties and abundant groups of ZIF-8, Pd carbide (Pd-C) is formed on the surface of Pd NCs after thermal treatment, which acts the active sites for PSH to propylene. More importantly, the content of Pd-C can be precisely controlled by altering the calcination temperature without aggregation of Pd NCs and obvious changes in the framework of ZIF-8. The formation of Pd-C on Pd NCs@ZIF-8 can strongly suppress the H2 adsorption, and thus selectively catalyze propyne to propylene. Consequently, the optimized catalyst (i.e., Pd NCs@ZIF-8-100) exhibits a propylene selectivity of 96.4% at a propyne conversion of 93.3% at 35 °C and atmospheric pressure. This work may not only provide an efficient catalyst for PSH, but also shed a new light on the catalytic application of ZIFs.展开更多
Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially ad...Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.展开更多
Transparency is often an important property in the practical applications of temperature-responsive shape-memory gels.We investigated the mechanism of significant transparency improvement upon a change in two copolyme...Transparency is often an important property in the practical applications of temperature-responsive shape-memory gels.We investigated the mechanism of significant transparency improvement upon a change in two copolymer gels with their molar ratios between stearyl acrylate and N,N-dimethylacrylamide from 1:1 to 0.75:1.By means of Flash DSC measurement,w e made the thermal analysis characterization of crystallization and glass transition in two copolymer gels and compared the results to the parallel experiments of corresponding homopolymers.The results showed that the slightly lower content of stearyl acrylate sequences suppresses crystallization in their side chains due to the chemical confinement of comonomers on copolymer crystallization;meanwhile it shifts up the glass transition temperature of the backbone N,N-dimethylacrylamide sequences.Eventually on cooling,crystallization gives its priority position to glass transition in copolymer gels,resulting in a higher transparency of the gel without losing the shape-memory performance.To confirm the chemical confinement,w e further compared the isothermal crystallization kinetics of stearyl acrylate side chains in the copolymer gel to that of their homopolymer.Our observations facilitate the rational design of the temperature-responsive shape-memory gels for the transparency property.展开更多
This study aimed to investigate the protective effect of nicotine on dopaminergic neurons and its mechanisms in mice with Parkinson disease(PD)induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).C57BL/6J mic...This study aimed to investigate the protective effect of nicotine on dopaminergic neurons and its mechanisms in mice with Parkinson disease(PD)induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).C57BL/6J mice were injected with MPTP for 8 days to establish a PD model.Nicotine was given for 10 days in the nicotine therapeutic group.Animals were examined behaviorally with the pole test and traction test.Tyrosine hydroxylase(TH)andγ-aminobutyric acid(GABA)were determined by using the immunocytochem-istry(ICC)method.The ultrastructural changes of the caudate nucleus(CN)were observed under electron microscopy.The results showed that pretreatment with nicotine could improve the dyskinesia of PD mice markedly.Simultaneously,TH-positive(P<0.01)neurons and GABA-positive(P<0.05)neurons in the nicotine therapeutic group were significantly more than those in the model group.The ultrastructural injury of the nicotine therapeutic group was also ameliorated.Nicotine has protective effects on theγ-aminobutyric acid neurons and dopaminergic neurons in the MPTP-treated mice.展开更多
基金The National High Technology Research and Development Program of China (863 Program), No. 2001AA216071Guangdong Health Bureau Scientific Funds, No. 2006345
文摘AIM: To compare the preservation of non-heart- beating donor (NHBD) livers in cold histidine-trytophan- ketoglutarate (HTK) solution and extracorporeal liver perfusion (ECLP). METHODS: Livers harvested from health pigs were stored for 10 h in cold HTK solution (group A, n = 4) or perfused with oxygenated autologous blood at body temperature (group B, n = 4). Both groups were then tested on the circuit for 4 h. Bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of extracorporeal livers were tested in each group. Liver tissues from each group were examined at the end of reperfusion. RESULTS: At 1, 2, 3 and 4 h after reperfusion, bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of livers in group A were statistically different from those in group B (P < 0.05 or P < 0.01). CONCLUSION: ECLP is better than HTK solution to preserve NHBD livers. ECLP can assess the graft viabilitybefore liver transplantation.
基金Supported by: the National Natural Science Foundation of China, No. 30770737
文摘BACKGROUND： Studies have shown that scorpion venom heat-resistant protein （SVHRP） exhibits protective effects on primary cultured hippocampal neurons. OBJECTIVE： To determine the effects of SVHRP on astrocyte activity and synaptic density in the hippocampus induced by amyloid β peptide 1-40 （Aβ1-40） neurotoxicity. DESIGN, TIME AND SETTING： The randomized, controlled, animal experiment was performed at the Central Laboratory, the Laboratory of Human Anatomy, and the Laboratory of Physiology, in Dalian Medical University between March 2006 and June 2008. MATERIALS： Aβ1-40 was provided by Biosource, USA; SVHRP was a patented biological product of Dalian Medical University （No. ZL01 1 06166.9）. METHODS： A total of 27 healthy, 2-month-old, male SD rats were randomly assigned to 3 groups： control, Aβ, and SVHRP, with 9 rats in each group. Alzheimer＇s disease was simulated with 10 μg Aβ1-40 bilaterally injected into the hippocampus of the Aβ and SVHRP groups. The control group was injected with 2 μL 0.05% trifluoroacetic acid. One day following model establishment, the SVHRP group received an intraperitoneal injection of 2 μg/100 g SVHRP, while the control group and Aβ group received 0.5 mL/100 g tri-distilled water, once per day, for 10 consecutive days. MAIN OUTCOME MEASURES： At 16 days following model establishment, synaptophysin （p38） expression in CA1-CA4 regions of the rat hippocampus was determined by immunohistochemistry. Glial fibrillary acidic protein （GFAP） expression surrounding the hippocampal Aβ1-40 injected area was also detected. At 11 days following model establishment, escape latency, swimming time, and distance to target quadrant were measured using the Morris water maze. RESULTS： Compared with the control group, the Aβ group exhibited notably reduced p38 expression （P 〈 0.05） and notably increased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was prolonged （P 〈 0.05）, and swimming time and distance to the target quadrant were shortened in the Aβ group. Compared with the Aβ group, the SVHRP group exhibited notably increased p38 expression （P 〈 0.05） and notably decreased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was significantly reduced （P 〈 0.05）, and swimming time and distance to the target quadrant were significantly prolonged. CONCLUSION： SVHRP inhibited exogenous Aβ1-40-induced astrocyte activation and synaptic density decline in the rat hippocampus. Place navigation and spatial searching results showed that SVHRP blocked Aβ1-40-induced impaired learning and memory.
基金This work was supported by the National Natural Science Foundation of China (Nos. 21703146 and 51802206)Natural Science Foundation of Jiangsu Province (No. BK20180846)+1 种基金We also acknowledge the financial support from the 111 Project, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD),SWC for Synchrotron Radiation. Yong Xu acknowledges the financial support from Guangdong University of Technology.
文摘The selective hydrogenation of propyne to propylene has attracted great attention in chemical industry for removing trace amount of propyne for producing polymer-grade propylene. As the state-of-the-art catalyst, Pd suffers from the disadvantage of poor propylene selectivity due to the over-hydrogenation of propylene to propane. We here demonstrate that Pd nanocubes (NCs) coated by zeolitic imidazolate frameworks (i.e., Pd NCs@ZIF-8) can serve as highly active and selective catalysts for propyne selective hydrogenation (PSH). Benefitting from the unique properties and abundant groups of ZIF-8, Pd carbide (Pd-C) is formed on the surface of Pd NCs after thermal treatment, which acts the active sites for PSH to propylene. More importantly, the content of Pd-C can be precisely controlled by altering the calcination temperature without aggregation of Pd NCs and obvious changes in the framework of ZIF-8. The formation of Pd-C on Pd NCs@ZIF-8 can strongly suppress the H2 adsorption, and thus selectively catalyze propyne to propylene. Consequently, the optimized catalyst (i.e., Pd NCs@ZIF-8-100) exhibits a propylene selectivity of 96.4% at a propyne conversion of 93.3% at 35 °C and atmospheric pressure. This work may not only provide an efficient catalyst for PSH, but also shed a new light on the catalytic application of ZIFs.
基金This work was supported by the National Natural Science Foundation of China(Nos.51922073 and 21902109)the Natural Science Foundation of Jiangsu Province(Nos.BK20200960 and BK20180097)+1 种基金the Natural Science Foundation of Higher Education in Jiangsu Province(No.20KJB150041)the Natural Science Foundation of Nantong University for High-Level Talent(No.03083033).
文摘Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.
基金supported by the National Natural Science Foundation of China(Nos.21973042 and 21734005)Program for Changjiang Scholars and Innovative Research Teams(No.IRT1252)CAS Interdisciplinary Innovation Team,and JSPS KAKENHI 18K05228.
文摘Transparency is often an important property in the practical applications of temperature-responsive shape-memory gels.We investigated the mechanism of significant transparency improvement upon a change in two copolymer gels with their molar ratios between stearyl acrylate and N,N-dimethylacrylamide from 1:1 to 0.75:1.By means of Flash DSC measurement,w e made the thermal analysis characterization of crystallization and glass transition in two copolymer gels and compared the results to the parallel experiments of corresponding homopolymers.The results showed that the slightly lower content of stearyl acrylate sequences suppresses crystallization in their side chains due to the chemical confinement of comonomers on copolymer crystallization;meanwhile it shifts up the glass transition temperature of the backbone N,N-dimethylacrylamide sequences.Eventually on cooling,crystallization gives its priority position to glass transition in copolymer gels,resulting in a higher transparency of the gel without losing the shape-memory performance.To confirm the chemical confinement,w e further compared the isothermal crystallization kinetics of stearyl acrylate side chains in the copolymer gel to that of their homopolymer.Our observations facilitate the rational design of the temperature-responsive shape-memory gels for the transparency property.
基金supported by the Foundation of Education Department of Liaoning Province,China(No.20060211).
文摘This study aimed to investigate the protective effect of nicotine on dopaminergic neurons and its mechanisms in mice with Parkinson disease(PD)induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).C57BL/6J mice were injected with MPTP for 8 days to establish a PD model.Nicotine was given for 10 days in the nicotine therapeutic group.Animals were examined behaviorally with the pole test and traction test.Tyrosine hydroxylase(TH)andγ-aminobutyric acid(GABA)were determined by using the immunocytochem-istry(ICC)method.The ultrastructural changes of the caudate nucleus(CN)were observed under electron microscopy.The results showed that pretreatment with nicotine could improve the dyskinesia of PD mice markedly.Simultaneously,TH-positive(P<0.01)neurons and GABA-positive(P<0.05)neurons in the nicotine therapeutic group were significantly more than those in the model group.The ultrastructural injury of the nicotine therapeutic group was also ameliorated.Nicotine has protective effects on theγ-aminobutyric acid neurons and dopaminergic neurons in the MPTP-treated mice.
