Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be est...Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing （ADT） of NPMEs in acidic medium. Platinum used as the coun- ter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction （ORR） performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.展开更多
A dual random model of a portfolio of variable amount whole life annuity is set with the mth moment of the present value of benefits, and the respective expressions of the moments under the assumption that the force o...A dual random model of a portfolio of variable amount whole life annuity is set with the mth moment of the present value of benefits, and the respective expressions of the moments under the assumption that the force of interest accumulation function is Wiener process or Ornstein-Uhlenbeck process. Furthermore, the limiting distribution of average cost of this portfolio is discussed with the expression of the limiting distribution under the assumption that the force of interest accumulation is an independent increment process.展开更多
Not much data are available regarding the electrical activity in the stomachs and intestines of elderly gastrectomized patients The purpose of this study was to determine the feasibility of using a complex dynamic met...Not much data are available regarding the electrical activity in the stomachs and intestines of elderly gastrectomized patients The purpose of this study was to determine the feasibility of using a complex dynamic method to analyze the electrogastrograms （EGGs） of healthy young, healthy elderly, and gastrectomized elderly male individuals. The authors analyzed the EGGs by using the maximum Lyapunov exponent （MLE）, which is one of the indices of the chaotic characteristics of time series. Significant differences were observed between the MLEs estimated from the, EGGs of the young and elderly individuals for most of the temporal intervals. The authors＇ data indicate that the EGGs of elderly gastrectomized subjects might be distinguished from the EGGs of healthy elderly individuals on the basis of the MLE distribution.展开更多
The development of flexible transparent electrodes for next generation devices has been appointed as the major topic in carbon electronics research for the next five years. Among all candidate materials tested to date...The development of flexible transparent electrodes for next generation devices has been appointed as the major topic in carbon electronics research for the next five years. Among all candidate materials tested to date, graphene and graphene based nanocomposites have shown the highest performance. Although some incipient anti-oxidation tests have been reported, in-deep ageing studies to assess the reliability of carbon-based electrodes have never been performed before. In this work, we present a disruptive methodology to assess the ageing mechanisms of graphene electrodes, which is also extensible to other carbon- based and two-dimensional materials. After performing accelerated oxidative tests, we exhaustively analyze the yield of the electrodes combining nanoscale and device level experiments with Weibull probabilistic analyses and tunneling current simulation, based on the Fowler-Nordheim/Direct-Tunneling models. Our experiments and calculations reveal that an ultra-thin oxide layer can be formed on the pristine surface of graphene. We quantitatively analyze the consequences of this layer on the properties of the electrodes, and observed a change in the conduction mode at the interface （from Ohmic to Schottky）, an effect that should be considered in the design of future graphene-based devices. Future mass production of carbon-based devices should include similar reliability studies, and the methodologies presented here （including the accelerated tests, characterization and modeling） may help other scientists to move from lab prototypes towards industrial device production.展开更多
Purpose： To investigate the effects of estrogen G protein-coupled receptor 30 （GPR30） agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury （TBI）. Methods： Male S...Purpose： To investigate the effects of estrogen G protein-coupled receptor 30 （GPR30） agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury （TBI）. Methods： Male SD rats were randomly divided into sham group, TBI ＋ vehicle group, TBI ＋ G1 group. Experimental moderate TBI was induced using Feeney＇s weigh-drop method. GI （100μg/kg） or vehicle was intravenously injected from femoral vein at 30 rain post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. MI type microglia markers （iNOS and IL-113） and M2 type markers （Argl and IL-4） were examined by immunoblotting or ELLSA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting. Results： G1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1β production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt. Conclusions： GPR30 agonist GI inhibited neuronal apoptosis and favored microglia polarization to M2 type.展开更多
Objective： To introduce bipolar hemiarthroplasty with a two-step osteotomy technique and observe its clinical result for unstable intertrochanteric frac- tures in senile patients. Methods： Fifteen consecutive patie...Objective： To introduce bipolar hemiarthroplasty with a two-step osteotomy technique and observe its clinical result for unstable intertrochanteric frac- tures in senile patients. Methods： Fifteen consecutive patients with unstable intertrochanteric fractures aged from 81 to 92 years with a mean of 85 years were treated in our hospital from August 2006 to October 2011 （Evans type III in 4 cases, Evans type IV in 11 cases）, who received bipolar hemiarthroplasty with a two-step osteotomy technique performed by a senior or- thopedic surgeon through posterior approach under general anesthesia. All cases were evaluated by Zuckerman func- tional recovery score （FRS） and operative risk assessment software 1, based on the patients＇ physical and laboratory examinations preoperatively. The duration and blood loss have been recorded. There were 4 male cases （4 hips） and 11 female cases （11 hips）. All prostheses consisted of Link SP II femoral stem and bipolar femoral head. All patients were followed up for more than 1 year. Results： The average preoperative FRS, predictive value of operative morbidity and mortality were 83.7 （81.7- 85.9）, 9.3% （7.3%- 15.0%） and 3.5% （2.3%-4.2%）, respectively. The average operation time was 50 minutes with a mean intraoperative blood loss of 310 ml. There were no operative or anesthetic complications or deaths within 30 days after operation. Sitting up was permitted 3 to 4 days, and partial weight beating was allowed 5 to 7 days after operation. The average FRS was 79.3 at 30 days and 84.9 at 1 year postoperatively. Three patients died of unrelated causes （one due to myocardial infarction and the others due to cerebral hemorrhage during at least one-year follow-up）. Conclusion： Bipolar hemiarthroplasty with a two-step osteotomy technique for unstable intertrochanteric fractures in the senile patients is a good choice for early ambulation and good hip function.展开更多
Objective: To assess the effects of Tai Chi (Chinese shadow boxing exercise) for improving the lower-limb muscle strength in elderly people. Methods: The PUBMED database (from 1950), EMBASE-ASP database (from 1974), C...Objective: To assess the effects of Tai Chi (Chinese shadow boxing exercise) for improving the lower-limb muscle strength in elderly people. Methods: The PUBMED database (from 1950), EMBASE-ASP database (from 1974), Cochrane Library (from 1991), Elsevier sciences database (from 1990), OVID full text database (from 1997), Springer-link database (from 1997), The National Research Register database, ISI Web of knowledge (from 1963), Chinese Medical Citation Index/Chinese Medical Current Contents (CMCI/CMCC, from 1989), China Knowledge Resource Integrated Database (CNKI, from 1915),VIP database (from 1989), and Wanfang database (from 1977) have been searched only for the English and Chinese literatures updated to 10-30-2010. Two researchers independently assessed the methodological quality of studies, extracted and checked the data one another according to the include/exclude standards. Disagreement was resolved by discussions or with the third person. The Review Manage Software 5.0 was used for Meta-analysis. Results: Eventually, 2 randomized controled studies and 2 non-randomized controled studies met the inclusion criteria, with 163 subjects involved in the present meta-analysis. The meta-analysis demonstrated that Tai Chi exercise could improve the ankle flexor/extensor muscle strength and the knee extensor/flexor muscle strength, tested with an isokinetic dynamometer. The limb muscle strength increased significantly after Tai Chi exercise (P<0.01). Conclusion: The meta-analysis favours Tai Chi exercise for improving the lower-limb muscle strength in the older people.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(DUT15RC(3)001,DUT15ZD225)the Program for Liao-ning Excellent Talents in University(LR2015014)+1 种基金the Liaoning BaiQianWan Talents Program(201519)Dalian Excellent Young Scientific and Technological Talents(2015R006)
文摘Significant progress has been made in the development of non-precious metal electrocatalysts （NPMEs） during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing （ADT） of NPMEs in acidic medium. Platinum used as the coun- ter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction （ORR） performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.
文摘A dual random model of a portfolio of variable amount whole life annuity is set with the mth moment of the present value of benefits, and the respective expressions of the moments under the assumption that the force of interest accumulation function is Wiener process or Ornstein-Uhlenbeck process. Furthermore, the limiting distribution of average cost of this portfolio is discussed with the expression of the limiting distribution under the assumption that the force of interest accumulation is an independent increment process.
文摘Not much data are available regarding the electrical activity in the stomachs and intestines of elderly gastrectomized patients The purpose of this study was to determine the feasibility of using a complex dynamic method to analyze the electrogastrograms （EGGs） of healthy young, healthy elderly, and gastrectomized elderly male individuals. The authors analyzed the EGGs by using the maximum Lyapunov exponent （MLE）, which is one of the indices of the chaotic characteristics of time series. Significant differences were observed between the MLEs estimated from the, EGGs of the young and elderly individuals for most of the temporal intervals. The authors＇ data indicate that the EGGs of elderly gastrectomized subjects might be distinguished from the EGGs of healthy elderly individuals on the basis of the MLE distribution.
文摘The development of flexible transparent electrodes for next generation devices has been appointed as the major topic in carbon electronics research for the next five years. Among all candidate materials tested to date, graphene and graphene based nanocomposites have shown the highest performance. Although some incipient anti-oxidation tests have been reported, in-deep ageing studies to assess the reliability of carbon-based electrodes have never been performed before. In this work, we present a disruptive methodology to assess the ageing mechanisms of graphene electrodes, which is also extensible to other carbon- based and two-dimensional materials. After performing accelerated oxidative tests, we exhaustively analyze the yield of the electrodes combining nanoscale and device level experiments with Weibull probabilistic analyses and tunneling current simulation, based on the Fowler-Nordheim/Direct-Tunneling models. Our experiments and calculations reveal that an ultra-thin oxide layer can be formed on the pristine surface of graphene. We quantitatively analyze the consequences of this layer on the properties of the electrodes, and observed a change in the conduction mode at the interface （from Ohmic to Schottky）, an effect that should be considered in the design of future graphene-based devices. Future mass production of carbon-based devices should include similar reliability studies, and the methodologies presented here （including the accelerated tests, characterization and modeling） may help other scientists to move from lab prototypes towards industrial device production.
基金This work was supported by Natural Science Foundation of China （NSFC 81470599）.
文摘Purpose： To investigate the effects of estrogen G protein-coupled receptor 30 （GPR30） agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury （TBI）. Methods： Male SD rats were randomly divided into sham group, TBI ＋ vehicle group, TBI ＋ G1 group. Experimental moderate TBI was induced using Feeney＇s weigh-drop method. GI （100μg/kg） or vehicle was intravenously injected from femoral vein at 30 rain post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. MI type microglia markers （iNOS and IL-113） and M2 type markers （Argl and IL-4） were examined by immunoblotting or ELLSA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting. Results： G1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1β production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt. Conclusions： GPR30 agonist GI inhibited neuronal apoptosis and favored microglia polarization to M2 type.
文摘Objective： To introduce bipolar hemiarthroplasty with a two-step osteotomy technique and observe its clinical result for unstable intertrochanteric frac- tures in senile patients. Methods： Fifteen consecutive patients with unstable intertrochanteric fractures aged from 81 to 92 years with a mean of 85 years were treated in our hospital from August 2006 to October 2011 （Evans type III in 4 cases, Evans type IV in 11 cases）, who received bipolar hemiarthroplasty with a two-step osteotomy technique performed by a senior or- thopedic surgeon through posterior approach under general anesthesia. All cases were evaluated by Zuckerman func- tional recovery score （FRS） and operative risk assessment software 1, based on the patients＇ physical and laboratory examinations preoperatively. The duration and blood loss have been recorded. There were 4 male cases （4 hips） and 11 female cases （11 hips）. All prostheses consisted of Link SP II femoral stem and bipolar femoral head. All patients were followed up for more than 1 year. Results： The average preoperative FRS, predictive value of operative morbidity and mortality were 83.7 （81.7- 85.9）, 9.3% （7.3%- 15.0%） and 3.5% （2.3%-4.2%）, respectively. The average operation time was 50 minutes with a mean intraoperative blood loss of 310 ml. There were no operative or anesthetic complications or deaths within 30 days after operation. Sitting up was permitted 3 to 4 days, and partial weight beating was allowed 5 to 7 days after operation. The average FRS was 79.3 at 30 days and 84.9 at 1 year postoperatively. Three patients died of unrelated causes （one due to myocardial infarction and the others due to cerebral hemorrhage during at least one-year follow-up）. Conclusion： Bipolar hemiarthroplasty with a two-step osteotomy technique for unstable intertrochanteric fractures in the senile patients is a good choice for early ambulation and good hip function.
文摘Objective: To assess the effects of Tai Chi (Chinese shadow boxing exercise) for improving the lower-limb muscle strength in elderly people. Methods: The PUBMED database (from 1950), EMBASE-ASP database (from 1974), Cochrane Library (from 1991), Elsevier sciences database (from 1990), OVID full text database (from 1997), Springer-link database (from 1997), The National Research Register database, ISI Web of knowledge (from 1963), Chinese Medical Citation Index/Chinese Medical Current Contents (CMCI/CMCC, from 1989), China Knowledge Resource Integrated Database (CNKI, from 1915),VIP database (from 1989), and Wanfang database (from 1977) have been searched only for the English and Chinese literatures updated to 10-30-2010. Two researchers independently assessed the methodological quality of studies, extracted and checked the data one another according to the include/exclude standards. Disagreement was resolved by discussions or with the third person. The Review Manage Software 5.0 was used for Meta-analysis. Results: Eventually, 2 randomized controled studies and 2 non-randomized controled studies met the inclusion criteria, with 163 subjects involved in the present meta-analysis. The meta-analysis demonstrated that Tai Chi exercise could improve the ankle flexor/extensor muscle strength and the knee extensor/flexor muscle strength, tested with an isokinetic dynamometer. The limb muscle strength increased significantly after Tai Chi exercise (P<0.01). Conclusion: The meta-analysis favours Tai Chi exercise for improving the lower-limb muscle strength in the older people.
