Oxygen reduction reaction(ORR)has been disclosed in recent studies as a significant secondary cathodic process during magnesium corrosion.This work elaborates on the contribution of ORR to the total corrosion process ...Oxygen reduction reaction(ORR)has been disclosed in recent studies as a significant secondary cathodic process during magnesium corrosion.This work elaborates on the contribution of ORR to the total corrosion process of pure Mg at different impurity levels in NaCl electrolyte with the assistance of local techniques.A finite element based numerical model taking into account the contribution of ORR during the corrosion of the Mg test materials has been designed in this study considering the local oxygen concentration.Respective computational simulations were calibrated based on the experimental data and evaluated accordingly.Finally,the simultaneous monitoring of local concentration of H_(2) and O_(2),and the combined modeling study reveal the relation between ORR and hydrogen evolution reaction.展开更多
Objectives:Non-healing wounds have been one of the major challenges in health care because of increased morbidity,especially for those who have diabetes mellitus.Numerous regimens are being innovated to produce an evi...Objectives:Non-healing wounds have been one of the major challenges in health care because of increased morbidity,especially for those who have diabetes mellitus.Numerous regimens are being innovated to produce an evidence-based practice that would minimize complications and promote healing.Topical oxygen therapy is an innovation in wound care that has been considered influential in the wound healing process.This intervention aims to increase the oxygen concentration in the affected limb to promote wound healing.Methods:This research applied an experimental design that targeted a total of 60 adult patients aged 45–64 years with diabetic foot ulcers.A randomized systematic sampling technique was used to allow equal chances and prevent bias.In total,30 patients in the control group received usual care for diabetic foot ulcers,and the remaining 30 patients in the experimental group received topical oxygen therapy together with standard care for diabetic foot ulcers.Subjects were assessed using the Wagner-Meggitt Wound Classification System.Results:The result proved that there was a significant difference in the wound grade of patients in the experimental group after the application of the usual wound care plus the topical oxygen therapy using Friedman's test.The control and experimental groups were compared using Mann–Whitney statistical analyses,and the results showed that there was a significant difference between the control and experimental groups after the application of topical oxygen therapy.Conclusions:Topical oxygen therapy was demonstrated to be effective to aid in the wound healing process of patients with diabetic foot ulcers.Fur ther research was recommended to improve the application of topical oxygen therapy to patients with chronic wounds and promote the wound healing process.展开更多
Ectothermic animals are tolerant of variable oxygen availability, whether low-oxygen levels constrain the fitness of ectotherms remains unclear. Nanorana parkeri, an anuran endemic to the southern Tibetan plateau, is ...Ectothermic animals are tolerant of variable oxygen availability, whether low-oxygen levels constrain the fitness of ectotherms remains unclear. Nanorana parkeri, an anuran endemic to the southern Tibetan plateau, is an excellent model with which to answer this question. In this study, we raised tadpoles ofN. parkeri in oxygenated water （high-oxygen group） and deoxygenated unchlorinated tap water （low-oxygen group） and monitored their growth, mortality, and telomere length. The growth rate for body length and body weight was higher in the low-oxygen group than in the high-oxygen group. However, dissolved oxygen did not affect development time, mortality, and telomere length of the tadpoles. These results suggest that although the oxygen concentration influenced some phenotype traits of plateau tadpoles, but it didn＇t influence the telomere length and survival rate, potential explanations are the local adaptation and N. parkeri tadpoles＇ wide oxygen tolerance, and fluctuant toxic content that resulted in little oxidative stress on tadpoles. These results indicated that low oxygen was not a stress to N. parkeri tadpoles＇ fitness and survival. This study is helpful in understanding the adaptation mechanisms of Tibetan plateau amphibians.展开更多
A single ZnO nanowire with intrinsic oxygen vacancies is utilized to fabricate four-contact device with focus ion beam lithography technique. Cathodoluminescent spectra indicate strong near-UV and green emission at bo...A single ZnO nanowire with intrinsic oxygen vacancies is utilized to fabricate four-contact device with focus ion beam lithography technique. Cathodoluminescent spectra indicate strong near-UV and green emission at both room temperature and low temperatures. Experimental measurement shows the temperature-dependent conductivity of the ZnO nanowire at low temperatures （below 100 K）. The further theoretical analysis confirms that weak localization plays an important role in the electrical transport, which is attributed to the surface states induced by plenty of oxygen vacancies in ZnO nanowire.展开更多
为了解岩溶碳循环及碳汇效应研究热点和发展方向,基于Web of Science核心合集引文索引数据库,对1997年1月1日-2023年6月30日间的573篇文献进行了文献计量学引文分析。利用Cite Space软件对关键词频率、国家(地区)和机构分布、作者影响...为了解岩溶碳循环及碳汇效应研究热点和发展方向,基于Web of Science核心合集引文索引数据库,对1997年1月1日-2023年6月30日间的573篇文献进行了文献计量学引文分析。利用Cite Space软件对关键词频率、国家(地区)和机构分布、作者影响、研究热点、共被引文献以及主题演变进行了分析。结果表明,以刘再华为核心的研究团队继承和发扬了袁道先提出的岩溶作用参与全球碳循环并具有碳汇效应的观点,并提出了偶联碳酸盐岩风化碳汇模型,极大推动了岩溶碳汇的研究。关键词聚类的时间线图和关键词时区图清楚地展现了该领域的发展动态,可认为岩溶碳循环及碳汇效应领域经历3个发展阶段:1)1997-2006年的起步阶段,粗略估算了全球碳酸盐岩风化回收大气CO_(2)的量为0.110~0.608 Gt C·a^(-1),占全球碳遗漏的15%~30%;2)2007-2014年的碳酸盐岩化学风化研究快速发展阶段,主要关注不同流域在外源酸、径流条件及植被覆盖对碳酸盐岩风化的影响;3)2015年之后以大气-生物-土壤-水-基岩为系统的岩溶关键带理论指导下的碳循环及碳汇效应研究新阶段,考虑了水生生物光合作用、气候变化及土地利用变化等条件下岩溶碳循环及碳汇效应。展开更多
基金the China Scholarship Council for the award of fellowship and funding(No.201806310128,201908510177)。
文摘Oxygen reduction reaction(ORR)has been disclosed in recent studies as a significant secondary cathodic process during magnesium corrosion.This work elaborates on the contribution of ORR to the total corrosion process of pure Mg at different impurity levels in NaCl electrolyte with the assistance of local techniques.A finite element based numerical model taking into account the contribution of ORR during the corrosion of the Mg test materials has been designed in this study considering the local oxygen concentration.Respective computational simulations were calibrated based on the experimental data and evaluated accordingly.Finally,the simultaneous monitoring of local concentration of H_(2) and O_(2),and the combined modeling study reveal the relation between ORR and hydrogen evolution reaction.
文摘Objectives:Non-healing wounds have been one of the major challenges in health care because of increased morbidity,especially for those who have diabetes mellitus.Numerous regimens are being innovated to produce an evidence-based practice that would minimize complications and promote healing.Topical oxygen therapy is an innovation in wound care that has been considered influential in the wound healing process.This intervention aims to increase the oxygen concentration in the affected limb to promote wound healing.Methods:This research applied an experimental design that targeted a total of 60 adult patients aged 45–64 years with diabetic foot ulcers.A randomized systematic sampling technique was used to allow equal chances and prevent bias.In total,30 patients in the control group received usual care for diabetic foot ulcers,and the remaining 30 patients in the experimental group received topical oxygen therapy together with standard care for diabetic foot ulcers.Subjects were assessed using the Wagner-Meggitt Wound Classification System.Results:The result proved that there was a significant difference in the wound grade of patients in the experimental group after the application of the usual wound care plus the topical oxygen therapy using Friedman's test.The control and experimental groups were compared using Mann–Whitney statistical analyses,and the results showed that there was a significant difference between the control and experimental groups after the application of topical oxygen therapy.Conclusions:Topical oxygen therapy was demonstrated to be effective to aid in the wound healing process of patients with diabetic foot ulcers.Fur ther research was recommended to improve the application of topical oxygen therapy to patients with chronic wounds and promote the wound healing process.
基金supported by National Natural Science Foundation of China (No. 31471994)
文摘Ectothermic animals are tolerant of variable oxygen availability, whether low-oxygen levels constrain the fitness of ectotherms remains unclear. Nanorana parkeri, an anuran endemic to the southern Tibetan plateau, is an excellent model with which to answer this question. In this study, we raised tadpoles ofN. parkeri in oxygenated water （high-oxygen group） and deoxygenated unchlorinated tap water （low-oxygen group） and monitored their growth, mortality, and telomere length. The growth rate for body length and body weight was higher in the low-oxygen group than in the high-oxygen group. However, dissolved oxygen did not affect development time, mortality, and telomere length of the tadpoles. These results suggest that although the oxygen concentration influenced some phenotype traits of plateau tadpoles, but it didn＇t influence the telomere length and survival rate, potential explanations are the local adaptation and N. parkeri tadpoles＇ wide oxygen tolerance, and fluctuant toxic content that resulted in little oxidative stress on tadpoles. These results indicated that low oxygen was not a stress to N. parkeri tadpoles＇ fitness and survival. This study is helpful in understanding the adaptation mechanisms of Tibetan plateau amphibians.
基金supported by the National Natural Science Foundation of China (Grant Nos 60771037 and 90406022)the National High Technology Research and Development Program of China (Grant No 2008AA03Z309)the National Key Basic Research Program of China (Grant Nos 2007CB936802 and 2007CB935503)
文摘A single ZnO nanowire with intrinsic oxygen vacancies is utilized to fabricate four-contact device with focus ion beam lithography technique. Cathodoluminescent spectra indicate strong near-UV and green emission at both room temperature and low temperatures. Experimental measurement shows the temperature-dependent conductivity of the ZnO nanowire at low temperatures （below 100 K）. The further theoretical analysis confirms that weak localization plays an important role in the electrical transport, which is attributed to the surface states induced by plenty of oxygen vacancies in ZnO nanowire.
