A formula was proposed to calculate the distribution of metal ions quantitatively in chemical reaction system forming hydroxide where precipitation and complex are formed together. The effects of some factors on forma...A formula was proposed to calculate the distribution of metal ions quantitatively in chemical reaction system forming hydroxide where precipitation and complex are formed together. The effects of some factors on formation of precipitation and complex were investigated, and the corresponding precipitation rates of zinc, iron (III), aluminum, copper and magnesium were calculated. As a result, it shows that the proposed formula is reliable. By the proposed formula, the existence state of metal ions in hydroxides reaction system with any metal ions can be well described and the effects of some factors on the distribution of metal ions were determined.展开更多
Classical plate theory has been used to find out interfacial stress intensity factors in composite laminates. By using a well-known relation between the crack-tip energy release rate and the complex stress intensity f...Classical plate theory has been used to find out interfacial stress intensity factors in composite laminates. By using a well-known relation between the crack-tip energy release rate and the complex stress intensity factor. a closed-form solution for complex. Stress intensity in terms of external loading and a mode mix parameter for fairly. general composite laminates is given. Then a procedure for determining this mode mix. parameter is presented. followed by numerical results for some laminates. Small scale contact condition is expressed in terms of external loading In particular, a symmetric property of interfacial toughness curye is proven. Finally. the accuracy of failure load predicled by elininating oscllation index is discussed. and an example is presented to show the validity and limitation of β=0 approximation.展开更多
Background:Triage trauma scores are utilised to determine patient disposition,interventions and prognostication in the care of trauma patients.Heart rate variability(HRV)and heart rate complexity(HRC)reflect the auton...Background:Triage trauma scores are utilised to determine patient disposition,interventions and prognostication in the care of trauma patients.Heart rate variability(HRV)and heart rate complexity(HRC)reflect the autonomic nervous system and are derived from electrocardiogram(ECG)analysis.In this study,we aimed to develop a model incorporating HRV and HRC,to predict the need for life-saving interventions(LSI)in trauma patients,within 24 h of emergency department presentation.Methods:We included adult trauma patients(≥18 years of age)presenting at the emergency department of Singapore General Hospital between October 2014 and October 2015.We excluded patients who had non-sinus rhythms and larger proportions of artefacts and/or ectopics in ECG analysis.We obtained patient demographics,laboratory results,vital signs and outcomes from electronic health records.We conducted univariate and multivariate analyses for predictive model building.Results:Two hundred and twenty-five patients met inclusion criteria,in which 49 patients required LSIs.The LSI group had a higher proportion of deaths(10,20.41%vs 1,0.57%,p<0.001).In the LSI group,the mean of detrended fluctuation analysis(DFA)-α1(1.24 vs 1.12,p=0.045)and the median of DFA-α2(1.09 vs 1.00,p=0.027)were significantly higher.Multivariate stepwise logistic regression analysis determined that a lower Glasgow Coma Scale,a higher DFA-α1 and higher DFA-α2 were independent predictors of requiring LSIs.The area under the curve(AUC)for our model(0.75,95%confidence interval,0.66–0.83)was higher than other scoring systems and selected vital signs.Conclusions:An HRV/HRC model outperforms other triage trauma scores and selected vital signs in predicting the need for LSIs but needs to be validated in larger patient populations.展开更多
The kinetics of ternary complex formation involving Cu(5-X-1, 10-phen) and threonine (CuAL, A=5-X-1, 10-phen; L=threonine or represented by O-N; X=NO_2, Cl, H, CH_3) has been studied by temperature-jump and stopped-fl...The kinetics of ternary complex formation involving Cu(5-X-1, 10-phen) and threonine (CuAL, A=5-X-1, 10-phen; L=threonine or represented by O-N; X=NO_2, Cl, H, CH_3) has been studied by temperature-jump and stopped-flow methods. The formation rate constants, k_f(M^(-1).s^(-1)), for the complexation reaction, CuA + LCuAL, are as follows; X=NO_2, 8.68×10~8; X=Cl, 7.13×10~8; X=H, 6.12×10~8; X=CH_3, 5.42×10~8. The rate constants for zwitterion attack are nil within experimental error. It has been found that a linear free energy relationship exists between the stability(logK_(CuAL)^(CuA) of the complexes CuAL and log kf as follows: IogK_(CuAL)^(CuA)=0.13 + 0.83 logk_f, r=0.99. It suggested that the formation rate governed the stability of the ternary complexes. The rates of formation of the ternary complexes increased with decreasing electron-donating property of the substituents. A linear relationship was found to exist as expressed by the following equation: log(k_f^R/k_F^O) = 0.097σ, r=0.96. A mechanism involves a rapid equilibrium between CuA and L followed by a slow ring closure of L.展开更多
基金Project (51304047) supported by the National Natural Science Foundation of ChinaProject (20131037) supported by Science and Technology Foundation of Liaoning Province,China
文摘A formula was proposed to calculate the distribution of metal ions quantitatively in chemical reaction system forming hydroxide where precipitation and complex are formed together. The effects of some factors on formation of precipitation and complex were investigated, and the corresponding precipitation rates of zinc, iron (III), aluminum, copper and magnesium were calculated. As a result, it shows that the proposed formula is reliable. By the proposed formula, the existence state of metal ions in hydroxides reaction system with any metal ions can be well described and the effects of some factors on the distribution of metal ions were determined.
文摘Classical plate theory has been used to find out interfacial stress intensity factors in composite laminates. By using a well-known relation between the crack-tip energy release rate and the complex stress intensity factor. a closed-form solution for complex. Stress intensity in terms of external loading and a mode mix parameter for fairly. general composite laminates is given. Then a procedure for determining this mode mix. parameter is presented. followed by numerical results for some laminates. Small scale contact condition is expressed in terms of external loading In particular, a symmetric property of interfacial toughness curye is proven. Finally. the accuracy of failure load predicled by elininating oscllation index is discussed. and an example is presented to show the validity and limitation of β=0 approximation.
文摘Background:Triage trauma scores are utilised to determine patient disposition,interventions and prognostication in the care of trauma patients.Heart rate variability(HRV)and heart rate complexity(HRC)reflect the autonomic nervous system and are derived from electrocardiogram(ECG)analysis.In this study,we aimed to develop a model incorporating HRV and HRC,to predict the need for life-saving interventions(LSI)in trauma patients,within 24 h of emergency department presentation.Methods:We included adult trauma patients(≥18 years of age)presenting at the emergency department of Singapore General Hospital between October 2014 and October 2015.We excluded patients who had non-sinus rhythms and larger proportions of artefacts and/or ectopics in ECG analysis.We obtained patient demographics,laboratory results,vital signs and outcomes from electronic health records.We conducted univariate and multivariate analyses for predictive model building.Results:Two hundred and twenty-five patients met inclusion criteria,in which 49 patients required LSIs.The LSI group had a higher proportion of deaths(10,20.41%vs 1,0.57%,p<0.001).In the LSI group,the mean of detrended fluctuation analysis(DFA)-α1(1.24 vs 1.12,p=0.045)and the median of DFA-α2(1.09 vs 1.00,p=0.027)were significantly higher.Multivariate stepwise logistic regression analysis determined that a lower Glasgow Coma Scale,a higher DFA-α1 and higher DFA-α2 were independent predictors of requiring LSIs.The area under the curve(AUC)for our model(0.75,95%confidence interval,0.66–0.83)was higher than other scoring systems and selected vital signs.Conclusions:An HRV/HRC model outperforms other triage trauma scores and selected vital signs in predicting the need for LSIs but needs to be validated in larger patient populations.
文摘The kinetics of ternary complex formation involving Cu(5-X-1, 10-phen) and threonine (CuAL, A=5-X-1, 10-phen; L=threonine or represented by O-N; X=NO_2, Cl, H, CH_3) has been studied by temperature-jump and stopped-flow methods. The formation rate constants, k_f(M^(-1).s^(-1)), for the complexation reaction, CuA + LCuAL, are as follows; X=NO_2, 8.68×10~8; X=Cl, 7.13×10~8; X=H, 6.12×10~8; X=CH_3, 5.42×10~8. The rate constants for zwitterion attack are nil within experimental error. It has been found that a linear free energy relationship exists between the stability(logK_(CuAL)^(CuA) of the complexes CuAL and log kf as follows: IogK_(CuAL)^(CuA)=0.13 + 0.83 logk_f, r=0.99. It suggested that the formation rate governed the stability of the ternary complexes. The rates of formation of the ternary complexes increased with decreasing electron-donating property of the substituents. A linear relationship was found to exist as expressed by the following equation: log(k_f^R/k_F^O) = 0.097σ, r=0.96. A mechanism involves a rapid equilibrium between CuA and L followed by a slow ring closure of L.