This paper constructs a more unified measurement framework from the perspective of the Leontief inverse matrix and Ghosh inverse matrix(Ghosh).At the same time,referring to the four-term decomposition method of Leonti...This paper constructs a more unified measurement framework from the perspective of the Leontief inverse matrix and Ghosh inverse matrix(Ghosh).At the same time,referring to the four-term decomposition method of Leontief inverse matrix in Muradov(2016),this paper analyzes the structural decomposition of the cumulative tariff cost rate.Results show that(1)Overall,from 2000 to 2017,China's cumulative tariff cost rate,direct tariff cost rate,and multi-stage tariff cost rate all showed a downward trend,and the decline was greater than that of other countries(regions).China has strictly fulflled its WTO accession commitments and has greatly reduced the tariff rate on imported intermediate goods.(2)With China's deep participation in the global value chain,the amplification effect of China's tariffs has increased from 2.57 in 2000 to 3.17 in 2017,and there is a certain degree of"amplification effect"(above 1.5)in tariffs in all countries in the world.(3)From the perspective of the contribution rate of various countries in the world,China contributes the most to the global cumulative tariff cost rate,which is due to the complexity of the global production network structure,rather than the excessively high tariff rate imposed by China on imported intermediate goods.In terms of policy implications,if China did not take the initiative to reduce tariffs,the structural changes in the global production network would lead to a larger global cumulative tariff cost rate.展开更多
There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with1...There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with17 315 cycles,in three reproductive centers to evaluate two estimated parameters of CLBRs with multiple transfer cycles of in vitro fertilization(IVF)/intracytoplasmic sperm injection(ICSI) in a Chinese population.We found that CLBRs were related to female age and endometrial thickness.By the fourth transfer cycle,the conservative and optimal estimates of CLBRs were 52.95% and 77.30% in women under 30 years of age,and 18.17% and26.51% in those 37 years of age or older,respectively.The two estimates were 44.70% and 63.15% in women with endometrial thickness more than 7 mm,and 32.05% and 46.18% in those with less than 7 mm,respectively.In addition,body mass index(BMI),duration of infertility,and infertility diagnoses may also be related to CLBRs on certain conditions.The findings from this study on CLBRs after multiple transfer cycles of IVF/ICSI treatment on different conditions in the Chinese population should be beneficial to both infertile couples and clinicians.展开更多
Objective It is well known that a dual trigger treatment can improve clinical outcomes of in vitro fertilization(IVF)in high or normal ovarian responders.However,it is not clear whether dual triggering also benefits p...Objective It is well known that a dual trigger treatment can improve clinical outcomes of in vitro fertilization(IVF)in high or normal ovarian responders.However,it is not clear whether dual triggering also benefits patients with diminished ovarian reserve(DOR).The aim of this study was to investigate whether a dual trigger treatment of gonadotropin-releasing hormone(GnRH)agonist combined with human chorionic gonadotropin(hCG)for final follicular maturation improves the cumulative live birth rate(CLBR)during the GnRH-antagonist cycle in patients with DOR.Methods This retrospective study included patients with DOR who received a GnRH-antagonist protocol during IVF and intracytoplasmic sperm injection(IVF-ICSI)cycles at Peking University People’s Hospital from January 1,2017 through December 31,2017.Oocyte maturation was triggered by GnRH combined with hCG(n=110)or hCG alone(n=71).Embryos were transferred on the third day after oocyte retrieval or during a subsequent freeze-thaw cycle.Patients were followed up for 3 years.Results The dual trigger treatment did not affect CLBR,which is an overall determinant of the success rate of assisted reproductive technology(ART).Women in the dual trigger group had significantly higher rates of fertilization than those in the hCG group(90.1%vs.83.9%,P=0.040).Conclusion Dual trigger with GnRH agonist and hCG did not improve CLBR in patients with DOR,but did slightly improve fertilization rate,oocyte count,and embryo quality.展开更多
Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ri...Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ridge height and potential energy during wave-ridge interaction with a binary and cumulative logistic regression model. In testing the Global Null Hypothesis, all values are p 〈0.001, with three statistical methods, such as Likelihood Ratio, Score, and Wald. While comparing with two kinds of models, tests values obtained by cumulative logistic regression models are better than those by binary logistic regression models. Although this study employed cumulative logistic regression model, three probability functions p^1, p^2 and p^3, are utilized for investigating the weighted influence of factors on wave reflection. Deviance and Pearson tests are applied to cheek the goodness-of-fit of the proposed model. The analytical results demonstrated that both ridge height （X1 ） and potential energy （X2 ） significantly impact （p 〈 0. 0001 ） the amplitude-based refleeted rate; the P-values for the deviance and Pearson are all 〉 0.05 （0.2839, 0.3438, respectively）. That is, the goodness-of-fit between ridge height （ X1 ） and potential energy （X2） can further predict parameters under the scenario of the best parsimonious model. Investigation of 6 predictive powers （ R2, Max-rescaled R^2, Sorners＇ D, Gamma, Tau-a, and c, respectively） indicate that these predictive estimates of the proposed model have better predictive ability than ridge height alone, and are very similar to the interaction of ridge height and potential energy. It can be concluded that the goodness-of-fit and prediction ability of the cumulative logistic regression model are better than that of the binary logistic regression model.展开更多
Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozo...Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.展开更多
In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks,this study realizes the simulation of the welding process through elastic-plastic finite element theory,thermal-structural ...In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks,this study realizes the simulation of the welding process through elastic-plastic finite element theory,thermal-structural sequential coupling,and the birth-death element method.The simulated welding residual stresses are introduced into the multiscale finite element model of the bridge as the initial stress.Furthermore,the study explores the impact of residual stress on crack propagation in the fatigue-vulnerable components of the corroded steel box girder.The results indicate that fatigue cracks at the weld toe of the top deck,the weld root of the top deck,and the opening of the transverse diaphragm will not propagate under the action of a standard vehicle load.However,the inclusion of residual stress leads to the propagation of these cracks.When considering residual stress,the fatigue crack propagation paths at the weld toe of the transverse diaphragm and the U-rib weld toe align with those observed in actual bridges.In the absence of residual stress,the cracks at the toe of the transverse diaphragm with a 15%mass loss rate are categorized as type I cracks.Conversely,when residual stress is considered,these cracks become I-II composite cracks.Residual stress significantly alters the cumulative energy release rate of the three fracturemodes.Therefore,incorporating the influence of residual stress is essential when assessing the fatigue performance of corroded steel box girders in long-span bridges.展开更多
基金supported by the National Natural Science Foundation of China(71873142)the Humanities and Social Science Research Project of the Ministry of Education(20YJC790140)the National Natural Science Foundation of China(71733003).
文摘This paper constructs a more unified measurement framework from the perspective of the Leontief inverse matrix and Ghosh inverse matrix(Ghosh).At the same time,referring to the four-term decomposition method of Leontief inverse matrix in Muradov(2016),this paper analyzes the structural decomposition of the cumulative tariff cost rate.Results show that(1)Overall,from 2000 to 2017,China's cumulative tariff cost rate,direct tariff cost rate,and multi-stage tariff cost rate all showed a downward trend,and the decline was greater than that of other countries(regions).China has strictly fulflled its WTO accession commitments and has greatly reduced the tariff rate on imported intermediate goods.(2)With China's deep participation in the global value chain,the amplification effect of China's tariffs has increased from 2.57 in 2000 to 3.17 in 2017,and there is a certain degree of"amplification effect"(above 1.5)in tariffs in all countries in the world.(3)From the perspective of the contribution rate of various countries in the world,China contributes the most to the global cumulative tariff cost rate,which is due to the complexity of the global production network structure,rather than the excessively high tariff rate imposed by China on imported intermediate goods.In terms of policy implications,if China did not take the initiative to reduce tariffs,the structural changes in the global production network would lead to a larger global cumulative tariff cost rate.
基金supported by National Key Research&Development Program(Grant No.2016YFC1000200,No.2016YFC1000204,and No.2018YFC1004200)the State Key Program of National Natural Science of China(Grant No.31530047)+2 种基金National Natural Science Foundation of China(Grant No.81602927)Innovation Fund of State Key Laboratory of Reproductive Medicine(Grant No.SKLRMGC201802)Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(Grant No.PPZY2015A067)。
文摘There were few studies of cumulative live birth rates(CLBRs) based on multicenter reproductive clinical data from the general Chinese population.Here we report a retrospective cohort study,including 14 311 women with17 315 cycles,in three reproductive centers to evaluate two estimated parameters of CLBRs with multiple transfer cycles of in vitro fertilization(IVF)/intracytoplasmic sperm injection(ICSI) in a Chinese population.We found that CLBRs were related to female age and endometrial thickness.By the fourth transfer cycle,the conservative and optimal estimates of CLBRs were 52.95% and 77.30% in women under 30 years of age,and 18.17% and26.51% in those 37 years of age or older,respectively.The two estimates were 44.70% and 63.15% in women with endometrial thickness more than 7 mm,and 32.05% and 46.18% in those with less than 7 mm,respectively.In addition,body mass index(BMI),duration of infertility,and infertility diagnoses may also be related to CLBRs on certain conditions.The findings from this study on CLBRs after multiple transfer cycles of IVF/ICSI treatment on different conditions in the Chinese population should be beneficial to both infertile couples and clinicians.
基金supported by grants from the Scientific Research Development Fund of Peking University People’s Hospital(No.RDY2020-27)Clinical Medicine Plus X-Young Scholars Project,Peking University,and the Fundamental Research Funds for the Central Universities(No.PKU2021LCXQ020).
文摘Objective It is well known that a dual trigger treatment can improve clinical outcomes of in vitro fertilization(IVF)in high or normal ovarian responders.However,it is not clear whether dual triggering also benefits patients with diminished ovarian reserve(DOR).The aim of this study was to investigate whether a dual trigger treatment of gonadotropin-releasing hormone(GnRH)agonist combined with human chorionic gonadotropin(hCG)for final follicular maturation improves the cumulative live birth rate(CLBR)during the GnRH-antagonist cycle in patients with DOR.Methods This retrospective study included patients with DOR who received a GnRH-antagonist protocol during IVF and intracytoplasmic sperm injection(IVF-ICSI)cycles at Peking University People’s Hospital from January 1,2017 through December 31,2017.Oocyte maturation was triggered by GnRH combined with hCG(n=110)or hCG alone(n=71).Embryos were transferred on the third day after oocyte retrieval or during a subsequent freeze-thaw cycle.Patients were followed up for 3 years.Results The dual trigger treatment did not affect CLBR,which is an overall determinant of the success rate of assisted reproductive technology(ART).Women in the dual trigger group had significantly higher rates of fertilization than those in the hCG group(90.1%vs.83.9%,P=0.040).Conclusion Dual trigger with GnRH agonist and hCG did not improve CLBR in patients with DOR,but did slightly improve fertilization rate,oocyte count,and embryo quality.
基金This paper was financially supported by NSC96-2628-E-366-004-MY2 and NSC96-2628-E-132-001-MY2
文摘Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ridge height and potential energy during wave-ridge interaction with a binary and cumulative logistic regression model. In testing the Global Null Hypothesis, all values are p 〈0.001, with three statistical methods, such as Likelihood Ratio, Score, and Wald. While comparing with two kinds of models, tests values obtained by cumulative logistic regression models are better than those by binary logistic regression models. Although this study employed cumulative logistic regression model, three probability functions p^1, p^2 and p^3, are utilized for investigating the weighted influence of factors on wave reflection. Deviance and Pearson tests are applied to cheek the goodness-of-fit of the proposed model. The analytical results demonstrated that both ridge height （X1 ） and potential energy （X2 ） significantly impact （p 〈 0. 0001 ） the amplitude-based refleeted rate; the P-values for the deviance and Pearson are all 〉 0.05 （0.2839, 0.3438, respectively）. That is, the goodness-of-fit between ridge height （ X1 ） and potential energy （X2） can further predict parameters under the scenario of the best parsimonious model. Investigation of 6 predictive powers （ R2, Max-rescaled R^2, Sorners＇ D, Gamma, Tau-a, and c, respectively） indicate that these predictive estimates of the proposed model have better predictive ability than ridge height alone, and are very similar to the interaction of ridge height and potential energy. It can be concluded that the goodness-of-fit and prediction ability of the cumulative logistic regression model are better than that of the binary logistic regression model.
文摘Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.
基金supported by a grant from the Key Technologies Research and Development Program(No.2021YFF0602005)Jiangsu Key Research and Development Plan(Nos.BE2022129,BE2022134)the Fundamental Research Funds for the Central Universities(Nos.2242022k30031,2242022k30033),which are gratefully acknowledged.
文摘In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks,this study realizes the simulation of the welding process through elastic-plastic finite element theory,thermal-structural sequential coupling,and the birth-death element method.The simulated welding residual stresses are introduced into the multiscale finite element model of the bridge as the initial stress.Furthermore,the study explores the impact of residual stress on crack propagation in the fatigue-vulnerable components of the corroded steel box girder.The results indicate that fatigue cracks at the weld toe of the top deck,the weld root of the top deck,and the opening of the transverse diaphragm will not propagate under the action of a standard vehicle load.However,the inclusion of residual stress leads to the propagation of these cracks.When considering residual stress,the fatigue crack propagation paths at the weld toe of the transverse diaphragm and the U-rib weld toe align with those observed in actual bridges.In the absence of residual stress,the cracks at the toe of the transverse diaphragm with a 15%mass loss rate are categorized as type I cracks.Conversely,when residual stress is considered,these cracks become I-II composite cracks.Residual stress significantly alters the cumulative energy release rate of the three fracturemodes.Therefore,incorporating the influence of residual stress is essential when assessing the fatigue performance of corroded steel box girders in long-span bridges.
