To design a treatment plan for patients with epididymal obstruction,we explored the potential impact of factors such as body mass index(BMI)and age on the surgical outcomes of vasoepididymostomy(VE).In this retrospect...To design a treatment plan for patients with epididymal obstruction,we explored the potential impact of factors such as body mass index(BMI)and age on the surgical outcomes of vasoepididymostomy(VE).In this retrospective study,181 patients diagnosed with obstructive azoospermia(OA)due to epididymal obstruction between September 2014 and September 2017 were reviewed.All patients underwent single-armed microsurgical intussusception VEs with longitudinal two-suture placement performed by a single surgeon(KH)in a single hospital(Peking University Third Hospital,Beijing,China).Six factors that could possibly influence the patency rates were analyzed,including BMI,age,mode of anastomosis,site of anastomosis,and sperm motility and quantity in the intraoperative epididymal fluid.Single-factor outcome analysis was performed via Chi-square test and multivariable analysis was performed using logistic regression.A total of 159(87.8%,159/181)patients were followed up.The follow-up time(mean±standard deviation[s.d.])was 27.7±9.3 months,ranging from 12 months to 48 months.The overall patency rate was 73.0%(116/159).The multivariable analysis revealed that BMI and age significantly influenced the patency rate(P=0.008 and 0.028,respectively).Younger age(≤28 years;odds ratio[OR]=3.531,95%confidence interval[95%CI]:1.397–8.924)and lower BMI score(<26.0 kg m−2;OR=2.352,95%CI:1.095–5.054)appeared to be associated with a higher patency rate.BMI and age were independent factors affecting the outcomes of microsurgical VEs depending on surgical expertise and the use of advanced technology.展开更多
The changes of numeraire can be used as a very powerful mean in pricing contingent claims in the context of a complete market. We apply the method of nurmeraire changes to evaluate convertible bonds when the instantan...The changes of numeraire can be used as a very powerful mean in pricing contingent claims in the context of a complete market. We apply the method of nurmeraire changes to evaluate convertible bonds when the instantaneous growth and variance of the value of issuer and those of zero-coupon bonds follow a general adapted stochastic process in this paper. A closed-form solution is derived when the instantaneous growth and variance of the value of issuer and those of zero-coupon bonds are deterministic function of time. We also consider a special case when the asset price follows GBM （Geometric Brownian Motion） and interest rate follows Vasicek＇s model.展开更多
In this paper, we are concerned with the optimal hedge ratio under quantity risk as well as discrepancies between the futures market price and its theoretical valuation according to the cost- of-carry model. Assuming ...In this paper, we are concerned with the optimal hedge ratio under quantity risk as well as discrepancies between the futures market price and its theoretical valuation according to the cost- of-carry model. Assuming a geometric Brownian motion for forecasting process, we model mispricing as a specific noise corn poncnt in the dynamics of filturcs market prices, based on which the optimal hedging strategy is calculated. Finally, we illustrate optimal strategy and its properties by numerical examples.展开更多
基金This study was supported by Capital's Funds for Health Improvement and Research(No.2022-2-4094).
文摘To design a treatment plan for patients with epididymal obstruction,we explored the potential impact of factors such as body mass index(BMI)and age on the surgical outcomes of vasoepididymostomy(VE).In this retrospective study,181 patients diagnosed with obstructive azoospermia(OA)due to epididymal obstruction between September 2014 and September 2017 were reviewed.All patients underwent single-armed microsurgical intussusception VEs with longitudinal two-suture placement performed by a single surgeon(KH)in a single hospital(Peking University Third Hospital,Beijing,China).Six factors that could possibly influence the patency rates were analyzed,including BMI,age,mode of anastomosis,site of anastomosis,and sperm motility and quantity in the intraoperative epididymal fluid.Single-factor outcome analysis was performed via Chi-square test and multivariable analysis was performed using logistic regression.A total of 159(87.8%,159/181)patients were followed up.The follow-up time(mean±standard deviation[s.d.])was 27.7±9.3 months,ranging from 12 months to 48 months.The overall patency rate was 73.0%(116/159).The multivariable analysis revealed that BMI and age significantly influenced the patency rate(P=0.008 and 0.028,respectively).Younger age(≤28 years;odds ratio[OR]=3.531,95%confidence interval[95%CI]:1.397–8.924)and lower BMI score(<26.0 kg m−2;OR=2.352,95%CI:1.095–5.054)appeared to be associated with a higher patency rate.BMI and age were independent factors affecting the outcomes of microsurgical VEs depending on surgical expertise and the use of advanced technology.
基金Partially supported by the National Nature Science Foundation of ChinaThe Research Grants Council of HongKong Grant (No. 70731160635)
文摘The changes of numeraire can be used as a very powerful mean in pricing contingent claims in the context of a complete market. We apply the method of nurmeraire changes to evaluate convertible bonds when the instantaneous growth and variance of the value of issuer and those of zero-coupon bonds follow a general adapted stochastic process in this paper. A closed-form solution is derived when the instantaneous growth and variance of the value of issuer and those of zero-coupon bonds are deterministic function of time. We also consider a special case when the asset price follows GBM （Geometric Brownian Motion） and interest rate follows Vasicek＇s model.
基金Supported by the National Natural Science Foundation of China(No.70221001)
文摘In this paper, we are concerned with the optimal hedge ratio under quantity risk as well as discrepancies between the futures market price and its theoretical valuation according to the cost- of-carry model. Assuming a geometric Brownian motion for forecasting process, we model mispricing as a specific noise corn poncnt in the dynamics of filturcs market prices, based on which the optimal hedging strategy is calculated. Finally, we illustrate optimal strategy and its properties by numerical examples.
