Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM)...Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.展开更多
The research purpose on the healing of inner crack in metallic materials is to provide an effective approach for improving their properties and prolonging their lifetime. The crack healing process of 20MnMo steel with...The research purpose on the healing of inner crack in metallic materials is to provide an effective approach for improving their properties and prolonging their lifetime. The crack healing process of 20MnMo steel with inner pre-crack was analyzed. It was found that all inner cracks could be healed in different degree. There were very fine ferrite grains in healing region. The micro-crack healing process in single crystal of BBC-Fe was simulated by the molecule dynamics method, which showed that the critical temperature of crack healing in BBC-Fe is 673K. There were micro-voids, dislocations and twins left after crack healing.展开更多
Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokin...Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokines and angiogenic factors,mesenchymal stem cells(MSCs)have been acknowledged to be a potential agent in modulating wound healing process.However,post-transplanted MSCs are vulnerable to death,indicating poor survival and migration ability in the wound site of the host,especially under hyperglycemia.As hyperglycemia induces reactive oxygen species(ROS)generation and cellular apoptosis,improvement of MSCs survival and migration potentials under hyperglycemia could contribute to a more efficient MSCs-based wound healing therapy.Salidroside(Sa),a small-molecule drug derived from Rhodiola plant,has been proved to enhance the paracrine function of skeletal muscle cells,as well as their migration even under hypoxichyperglycemia.Herein,we investigated whether Sa could improve the survival and migration potentials of MSCs,subsequently enhance the wound healing process under hyperglycemia.Methods MSCs were cultured under three conditions:low glucose,high glucose,and high glucose+Sa.qPCR analysis and western blotting were done to examine the mRNA and protein expression level of several factors which are important in upregulating the wound healing process.MTT colorimetric assay,intracellular ROS detection,and flow cytometry assay were employed to examine the effect of Sa in MSCs survival.Transwell chamber assay,scratch assay,and phalloidin staining were done to elucidate the role of Sa in regulating MSCs migration potential.For in vivo experiment,diabetic wound healing mice model was generated to elucidate the effect of Sa-pretreated MSCs transplantation in wound closure rate,as well as re-epithelization status,observed with hematoxylin and eosin staining.The diabetic wound healing mice model were divided into three groups:1)mice injected with PBS,2)mice transplanted with PBS-pretreated MSCs,and 3)mice transplanted with Sa-pretreated MSCs.Results(1)Hyperglycemic condition induced the generation of ROS and suppressed total cell number of MSCs,while Sa treatment into MSCs restored these hyperglycemia-induced alterations.In line with this,total apoptotic cells were also suppressed by treating MSCs with Sa.The expression level of cell survival factor,heme-oxygenase 1(HO-1),was enhanced in Sa-pretreated MSCs.Further treatment of HO-1 inhibitor into Sa-pretreated MSCs nullified the ROS level and total apoptotic cells,indica-ting the importance of HO-1 in mediating the Sa-induced survival of MSCs under hyperglycemia.(2)Transwell chamber and scratch assay results showed that Sa-pretreated MSCs have a higher migration potential under hyperglycemia,supported by higher F-actin polymerization fractal dimension.Fibroblast growth factor 2(FGF2)and hepatocyte growth factor(HGF)expression level,which are essential factors for cell migration,were also improved in Sa-pretreated MSCs under hyperglycemia.(3)In diabetic wound healing mice model,transplantation of Sa-pretreated MSCs resulted in significantly improved wound closure rate and re-epithelization.The protein levels of HO-1,FGF2,and HGF were also enhanced in the tissues obtained from the wound site of diabetic wound healing mice model which were transplanted with Sa-pretreated MSCs.Conclusions Salidroside pretreatment on MSCs could improve their survival and migration potentials,subsequently promoting wound healing process under hyperglycemia.This prospective MSC-based therapy could serve as a novel strategy to improve diabetic wound healing.展开更多
The author and his coworkers presented a typical case of multiple seborrheic keratoses treated with CO2 laser.The surgical technique of vaporization of the skin lesions by CO2 laser was introduced.Complete healing wit...The author and his coworkers presented a typical case of multiple seborrheic keratoses treated with CO2 laser.The surgical technique of vaporization of the skin lesions by CO2 laser was introduced.Complete healing with good cosmetic results were obtained.No postoperative pain or complications were observed.展开更多
七十年代,联合国环境规划署(UNEP)建立了全球环境监测系统(GEMS),世界卫生组织(WHO)主持了与健康有关的监测活动(HEALTH RELATED MONITORING),开展了全球大气、水质、食品、生物(人血中铅、镉;人乳中有机氯)以及呼吸气个体接触量监测....七十年代,联合国环境规划署(UNEP)建立了全球环境监测系统(GEMS),世界卫生组织(WHO)主持了与健康有关的监测活动(HEALTH RELATED MONITORING),开展了全球大气、水质、食品、生物(人血中铅、镉;人乳中有机氯)以及呼吸气个体接触量监测.八十年代初,我国参加全部上述监测的合作规化,江苏省的无锡以及南京、常州等城市,分别参加了全球水质及生物监测点的工作.展开更多
文摘Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.
基金The authors acknowledge the support of the project of key program (59889101) of the National Natural Science Foundation of China (NSFC).
文摘The research purpose on the healing of inner crack in metallic materials is to provide an effective approach for improving their properties and prolonging their lifetime. The crack healing process of 20MnMo steel with inner pre-crack was analyzed. It was found that all inner cracks could be healed in different degree. There were very fine ferrite grains in healing region. The micro-crack healing process in single crystal of BBC-Fe was simulated by the molecule dynamics method, which showed that the critical temperature of crack healing in BBC-Fe is 673K. There were micro-voids, dislocations and twins left after crack healing.
基金Supported by grants from the National Natural Science Foundation of China ( 81372202,81872273, 31871367)
文摘Objective Diabetic patients pose a greater challenge in managing chronic wound healing,leading to a higher amputation risk compared to non-diabetic patients.Due to their paracrine function by secreting various cytokines and angiogenic factors,mesenchymal stem cells(MSCs)have been acknowledged to be a potential agent in modulating wound healing process.However,post-transplanted MSCs are vulnerable to death,indicating poor survival and migration ability in the wound site of the host,especially under hyperglycemia.As hyperglycemia induces reactive oxygen species(ROS)generation and cellular apoptosis,improvement of MSCs survival and migration potentials under hyperglycemia could contribute to a more efficient MSCs-based wound healing therapy.Salidroside(Sa),a small-molecule drug derived from Rhodiola plant,has been proved to enhance the paracrine function of skeletal muscle cells,as well as their migration even under hypoxichyperglycemia.Herein,we investigated whether Sa could improve the survival and migration potentials of MSCs,subsequently enhance the wound healing process under hyperglycemia.Methods MSCs were cultured under three conditions:low glucose,high glucose,and high glucose+Sa.qPCR analysis and western blotting were done to examine the mRNA and protein expression level of several factors which are important in upregulating the wound healing process.MTT colorimetric assay,intracellular ROS detection,and flow cytometry assay were employed to examine the effect of Sa in MSCs survival.Transwell chamber assay,scratch assay,and phalloidin staining were done to elucidate the role of Sa in regulating MSCs migration potential.For in vivo experiment,diabetic wound healing mice model was generated to elucidate the effect of Sa-pretreated MSCs transplantation in wound closure rate,as well as re-epithelization status,observed with hematoxylin and eosin staining.The diabetic wound healing mice model were divided into three groups:1)mice injected with PBS,2)mice transplanted with PBS-pretreated MSCs,and 3)mice transplanted with Sa-pretreated MSCs.Results(1)Hyperglycemic condition induced the generation of ROS and suppressed total cell number of MSCs,while Sa treatment into MSCs restored these hyperglycemia-induced alterations.In line with this,total apoptotic cells were also suppressed by treating MSCs with Sa.The expression level of cell survival factor,heme-oxygenase 1(HO-1),was enhanced in Sa-pretreated MSCs.Further treatment of HO-1 inhibitor into Sa-pretreated MSCs nullified the ROS level and total apoptotic cells,indica-ting the importance of HO-1 in mediating the Sa-induced survival of MSCs under hyperglycemia.(2)Transwell chamber and scratch assay results showed that Sa-pretreated MSCs have a higher migration potential under hyperglycemia,supported by higher F-actin polymerization fractal dimension.Fibroblast growth factor 2(FGF2)and hepatocyte growth factor(HGF)expression level,which are essential factors for cell migration,were also improved in Sa-pretreated MSCs under hyperglycemia.(3)In diabetic wound healing mice model,transplantation of Sa-pretreated MSCs resulted in significantly improved wound closure rate and re-epithelization.The protein levels of HO-1,FGF2,and HGF were also enhanced in the tissues obtained from the wound site of diabetic wound healing mice model which were transplanted with Sa-pretreated MSCs.Conclusions Salidroside pretreatment on MSCs could improve their survival and migration potentials,subsequently promoting wound healing process under hyperglycemia.This prospective MSC-based therapy could serve as a novel strategy to improve diabetic wound healing.
文摘The author and his coworkers presented a typical case of multiple seborrheic keratoses treated with CO2 laser.The surgical technique of vaporization of the skin lesions by CO2 laser was introduced.Complete healing with good cosmetic results were obtained.No postoperative pain or complications were observed.
文摘七十年代,联合国环境规划署(UNEP)建立了全球环境监测系统(GEMS),世界卫生组织(WHO)主持了与健康有关的监测活动(HEALTH RELATED MONITORING),开展了全球大气、水质、食品、生物(人血中铅、镉;人乳中有机氯)以及呼吸气个体接触量监测.八十年代初,我国参加全部上述监测的合作规化,江苏省的无锡以及南京、常州等城市,分别参加了全球水质及生物监测点的工作.
