Diesel soot subjected to high exhaust temperature suffers from thermal ageing,which is difficult to be removed by regeneration process.Based on the thermogravimetric(TG)analysis and images by high resolution transmiss...Diesel soot subjected to high exhaust temperature suffers from thermal ageing,which is difficult to be removed by regeneration process.Based on the thermogravimetric(TG)analysis and images by high resolution transmission electron microscope(HRTEM),effects of thermal ageing temperature,ageing time and oxygen concentration on oxidation characteristic of soot are investigated.The activation energy of soot increases with the increase of ageing temperature and oxygen concentration.The activation energy increases rapidly when the ageing time is less than 45 min,and then it keeps in a value of 157 kJ/mol when the ageing time is between 45 and 60 min.Compared to the soot without thermal ageing,the shape of ageing soot particles presents shorter diameter and more regular circle by observing soot nanostructure.With the increase of ageing temperature,ageing time and oxygen concentration,the more stable structure of“shell and core”is shown in the basic carbon.The soot has an increased fringe length,decreased tortuosity and separation distance after thermal ageing process,which leads to the deepening of the disorder degree of soot nanostructures and reduction of soot oxidation activity.Consequently,the thermal ageing process should be avoided in order to optimize the active regeneration strategy.展开更多
Objective:To examine the impact of a 6-week endurance training on red blood cell(RBC)aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.Meth...Objective:To examine the impact of a 6-week endurance training on red blood cell(RBC)aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.Methods:A total of 31 participants(17 females and 14 males)performed a 6-week moderate training protocol(three 1-h running sessions per week at 70%of maximal heart rate).Blood was sampled before and after the training.RBCs from each participant were fractioned according to density and age into 4 RBC subfractions.Subfractions were examined for changes of RBC properties,including aging distribution,RBC deformability,RBC microparticles,and phosphatidylserine concentrations.RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.Results:Aerobic performance,peak oxygen consumption,ventilatory thresholds,velocity at the aerobic-anaerobic threshold,and lactate at exhaustion improved after training.The relative amount of both young RBCs and old RBCs increased,and the amount of the main RBC fraction decreased.Phosphatidylserine externalization and RBC-derived microparticles decreased.Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs(p<0.001).Nitrite decreased in total(p=0.001),young(p<0.001),main(p<0.001),and old(p=0.020)aged RBCs and in plasma(p=0.002),but not in very old RBCs.Conclusion:These results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced,which might support oxygen supply in the microcirculation.展开更多
BACKGROUND： Prophylactic dietary restriction （DR）, whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective...BACKGROUND： Prophylactic dietary restriction （DR）, whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective efficacy of DR initiate late in life or accompany the aging process remains unclear.OBJECTIVE： The present study sought to： （1） determine if DR could protect against behavioral decline in mice when implemented during the aging process induced by D-galactose and （2） examine neuronal apoptosis in these aged brains and whether DR could block apoptosis.DESIGN, TIME AND SETTING： The randomized controlled animal study. The experiment was performed at the Experimental Animal Center of Capital Medical University and the Laboratory Center of School of Public Health of Captial Medical University of China from April 2006 to October 2007.MATERIALS： D-galactose （D-gal） was purchased from Beijing Chemical-Regent Company （Beijing, China）. Terminal transferase dUTP nick end labeling （TUNEL） detection kit was obtained from Roche, Germany. Assay kits for antioxidant enzyme activities and malondialdehyde contents were purchased from Jiancheng Institute of Biotechnology （Nanjing, China）. Morris water maze （Friends Honesty Life Sciences Co. Ltd., Hong Kong, China） and Flow Cytometry （Coulter, USA） were used in this study.METHODS： A total of 40 male Institute of Cancer Research （lCR） mice, 3 months old, were equally and randomly divided into D-gal treatment, DR treatment, D-gal ＋ DR treatment and normal control groups, and were then randomly assigned to one of two feeding regimens： ad libitum access to food or DR which received a 70% amount of daily food intake as that by ad libitum fed mice. There were two replicates per feeding regimen and mice were fed for 10 weeks,with or without a daily subcutaneous injection of D-gal at 100 mg/kg.MAIN OUTCOME MEASURES： Animals＇ spatial learning and memory performance were tested in the Morris water maze. Neuronal apoptosis rates were evaluated by Annexin V/flow cytometry assay and TUNEL assay. Lipid peroxidation levels and antioxidant defense capacity of the brain were measured using testing kits.RESULTS： DR markedly reduced the prolonged escape latency of D-gal mice in the water maze test （P〈0.01）. Annexin V and TUNEL assays showed that the D-gal mice had a significant higher percentage of neuronal apoptosis compared with normal control mice （P〈0.05）, and that DR treatment markedly decreased this apoptotic cell death （P〈0.05）. DR also reversed the decline of total superoxide dismutase and glutathione peroxidase activities and the increase of malondialdehyde levels in the brain of D-gal mice （P〈0.05, respectively）.CONCLUSION： DR reduces the impact of D-gal-induced brain aging in mice and can reverse performance decline and neurobiochemical impairments. These results demonstrate that implementation of DR in conditions of chronic oxidative stress can be neuroprotective, and that senium DR can be beneficial for healthy aging.展开更多
基金Project(51676167)supported by the National Natural Science Foundation of ChinaProject(17TD0035)supported by the Sichuan Provincial Scientific Research Innovation Team Program,ChinaProjects(2017TD0026,2015TD0021)supported by Science&Technology Department of Sichuan Province,China。
文摘Diesel soot subjected to high exhaust temperature suffers from thermal ageing,which is difficult to be removed by regeneration process.Based on the thermogravimetric(TG)analysis and images by high resolution transmission electron microscope(HRTEM),effects of thermal ageing temperature,ageing time and oxygen concentration on oxidation characteristic of soot are investigated.The activation energy of soot increases with the increase of ageing temperature and oxygen concentration.The activation energy increases rapidly when the ageing time is less than 45 min,and then it keeps in a value of 157 kJ/mol when the ageing time is between 45 and 60 min.Compared to the soot without thermal ageing,the shape of ageing soot particles presents shorter diameter and more regular circle by observing soot nanostructure.With the increase of ageing temperature,ageing time and oxygen concentration,the more stable structure of“shell and core”is shown in the basic carbon.The soot has an increased fringe length,decreased tortuosity and separation distance after thermal ageing process,which leads to the deepening of the disorder degree of soot nanostructures and reduction of soot oxidation activity.Consequently,the thermal ageing process should be avoided in order to optimize the active regeneration strategy.
基金supported by the Hochschulinterne Forschungsforderung(HIF)of the German Sport University Cologne.
文摘Objective:To examine the impact of a 6-week endurance training on red blood cell(RBC)aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.Methods:A total of 31 participants(17 females and 14 males)performed a 6-week moderate training protocol(three 1-h running sessions per week at 70%of maximal heart rate).Blood was sampled before and after the training.RBCs from each participant were fractioned according to density and age into 4 RBC subfractions.Subfractions were examined for changes of RBC properties,including aging distribution,RBC deformability,RBC microparticles,and phosphatidylserine concentrations.RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.Results:Aerobic performance,peak oxygen consumption,ventilatory thresholds,velocity at the aerobic-anaerobic threshold,and lactate at exhaustion improved after training.The relative amount of both young RBCs and old RBCs increased,and the amount of the main RBC fraction decreased.Phosphatidylserine externalization and RBC-derived microparticles decreased.Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs(p<0.001).Nitrite decreased in total(p=0.001),young(p<0.001),main(p<0.001),and old(p=0.020)aged RBCs and in plasma(p=0.002),but not in very old RBCs.Conclusion:These results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced,which might support oxygen supply in the microcirculation.
文摘BACKGROUND： Prophylactic dietary restriction （DR）, whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective efficacy of DR initiate late in life or accompany the aging process remains unclear.OBJECTIVE： The present study sought to： （1） determine if DR could protect against behavioral decline in mice when implemented during the aging process induced by D-galactose and （2） examine neuronal apoptosis in these aged brains and whether DR could block apoptosis.DESIGN, TIME AND SETTING： The randomized controlled animal study. The experiment was performed at the Experimental Animal Center of Capital Medical University and the Laboratory Center of School of Public Health of Captial Medical University of China from April 2006 to October 2007.MATERIALS： D-galactose （D-gal） was purchased from Beijing Chemical-Regent Company （Beijing, China）. Terminal transferase dUTP nick end labeling （TUNEL） detection kit was obtained from Roche, Germany. Assay kits for antioxidant enzyme activities and malondialdehyde contents were purchased from Jiancheng Institute of Biotechnology （Nanjing, China）. Morris water maze （Friends Honesty Life Sciences Co. Ltd., Hong Kong, China） and Flow Cytometry （Coulter, USA） were used in this study.METHODS： A total of 40 male Institute of Cancer Research （lCR） mice, 3 months old, were equally and randomly divided into D-gal treatment, DR treatment, D-gal ＋ DR treatment and normal control groups, and were then randomly assigned to one of two feeding regimens： ad libitum access to food or DR which received a 70% amount of daily food intake as that by ad libitum fed mice. There were two replicates per feeding regimen and mice were fed for 10 weeks,with or without a daily subcutaneous injection of D-gal at 100 mg/kg.MAIN OUTCOME MEASURES： Animals＇ spatial learning and memory performance were tested in the Morris water maze. Neuronal apoptosis rates were evaluated by Annexin V/flow cytometry assay and TUNEL assay. Lipid peroxidation levels and antioxidant defense capacity of the brain were measured using testing kits.RESULTS： DR markedly reduced the prolonged escape latency of D-gal mice in the water maze test （P〈0.01）. Annexin V and TUNEL assays showed that the D-gal mice had a significant higher percentage of neuronal apoptosis compared with normal control mice （P〈0.05）, and that DR treatment markedly decreased this apoptotic cell death （P〈0.05）. DR also reversed the decline of total superoxide dismutase and glutathione peroxidase activities and the increase of malondialdehyde levels in the brain of D-gal mice （P〈0.05, respectively）.CONCLUSION： DR reduces the impact of D-gal-induced brain aging in mice and can reverse performance decline and neurobiochemical impairments. These results demonstrate that implementation of DR in conditions of chronic oxidative stress can be neuroprotective, and that senium DR can be beneficial for healthy aging.
