The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and the...The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and then a geological model at different failure stages is proposed. The geological analysis shows that the excavation-induced repeated failures are related to the exposure of the weak bedding plane and the toe unloading of the cut slope, Numerical modeling is conducted based on a sequential method, taking into account the main failure stages of cut slope. The simulation results fairly coincide with the practical phenomena observed in field. It is shown that the decrease in normal stress of displaced mass on cut slope will induce the increase in shear stress in bedding planes and that at the toe of the cut slope. The released stress leads to repeated gravitational instabilities of cut slope due to the decrease in normal stress and the increase in shear stress along the bedding planes of mudstone.展开更多
Long-term gonadotropin-releasing hormone agonist（Gn RHa） administration before in vitro fertilization（IVF）/intracytoplasmic sperm injection（ICSI） in infertile women with endometriosis or adenomyosis significantl...Long-term gonadotropin-releasing hormone agonist（Gn RHa） administration before in vitro fertilization（IVF）/intracytoplasmic sperm injection（ICSI） in infertile women with endometriosis or adenomyosis significantly enhanced the chances of pregnancy in both fresh and frozen embryo transfer cycles. We hypothesized that long-term Gn RHa treatment might also be beneficial for the idiopathic repeated implantation failure（RIF） patients. In the 21 patients receiving Gn RHa and hormone replacement therapy（G-HRT） protocols for frozen embryo transfer, their data were compared with those of the 56 of frozen/fresh cycles they had previously undergone（previous protocols）. Comparison showed that the finial results were significantly better with G-HRT protocols than with their previous protocols, with pregnancy rate, clinical pregnancy rate, implantation rate and on-going pregnancy rate being 70%, 60%, 40% and 38% respectively with G-HRT protocols, against 17%, 11%, 6.3% and 5% with previous protocols. The results showed that hormonally controlled endometrial preparation with prior Gn RHa suppression could be used for patients who had experienced repeated failures of IVF treatment despite having morphologically optimal embryos, and the treatment may help increase the receptivity of the endometrium in these patients.展开更多
Using self-made impact fatigue test instruments and related analytic devices,the mechanical components with laser cladding layer have been attempted. It is found that, onrepeated impact force, several failure modes of...Using self-made impact fatigue test instruments and related analytic devices,the mechanical components with laser cladding layer have been attempted. It is found that, onrepeated impact force, several failure modes of the components include the surface cracks, surfaceplastic deformation, corrosive pitting and coat collapse, etc. The paper reported the test methodand initial analysis conclusions about the unique failure characteristics of the mechanicalcomponents on repeated impact load.展开更多
Objective\ The relationship between graft blood flow, epicardial microflow, mean arterial pressure and hemorheologic changes was studied during intraoperative heart failure. Methods\ These parameters were done to ...Objective\ The relationship between graft blood flow, epicardial microflow, mean arterial pressure and hemorheologic changes was studied during intraoperative heart failure. Methods\ These parameters were done to evaluate the use of repeated cardiopulmonary bypass support for the intraoperative heart failure following aorto coronary bypass surgery. Included in this study were 10 patients with a mean age of 70 and unstable angina undergoing coronary bypass grafting and suffering from intraoperative heart failure. The epicardiai microflow, graft flow, mean arterial pressure and blood cell filterability were measured. Resluts\ During heart failure, the mean arterial pressure fell by 41%(P<0.01), graft flow by 67%(P<0.01) and epicardialmicroflow by 64%(P<0.01). After 15 to 56 min of assisted cardiopulmonary bypass support, the epicardial microflow and graft flow were partially restored, while red cell and white cell filterability was reduced by 31% and 64% respectively (P<0.01). There were significant correlations between graft flow, epicardial microflow, blood cell filterability and cardiopulmonary bypass time. All patients recovered and were discharged from the hospital.Conclusion\ It is concluded that the use of temporary assisted CPB support to treat intrapoperative heart failure allows the recovery of the myocardium and thereby restores the mean arterial pressure. The recovery of graft flow and epicardial flow occurred to a lesser extent. The CPB support seemed to be suitable for about 60 min probably because of increasing disturbance to the blood cell filterability, graft flow and the epicardial microcirculation.\;展开更多
Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of intere...Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of interest has already happened when they come back. In this case, not only are their event times interval-censored, but also their time-dependent measurements are incomplete. This problem was motivated by a national longitudinal survey of youth data. Maximum likelihood estimation (MLE) method based on expectation-maximization (EM) algorithm is used for parameter estimation. Then missing information principle is applied to estimate the variance-covariance matrix of the MLEs. Simulation studies demonstrate that the proposed method works well in terms of bias, standard error, and power for samples of moderate size. The national longitudinal survey of youth 1997 (NLSY97) data is analyzed for illustration.展开更多
Objective:The objective of this study is to study whether preimplantation genetic testing for aneuploidy(PGT-A)improves the clinical outcomes of infertile patients with repeated implantation failure(RIF)undergoing fro...Objective:The objective of this study is to study whether preimplantation genetic testing for aneuploidy(PGT-A)improves the clinical outcomes of infertile patients with repeated implantation failure(RIF)undergoing frozen-thawed embryo transfer.Methods:This is a retrospective analysis of clinical pregnancy,live birth,miscarriage rates,and obstetric and perinatal outcomes of women with RIF with or without PGT-A.Statistical analyses of categorical data were performed using propensity score matching(PSM),χ^(2)test,and Student’s t test.Results:We enrolled 466 patients with RIF,of which,209 were in the RIF-PGT-A group.The rate of euploid blastocysts was significantly associated with age and day 5 or 6 blastocysts.There were significant differences between the RIF-PGT-A group and the RIF-non-PGT-A group across several parameters.After PSM,positive serum human chorionic gonadotropin(56.9%and 33.9%,P<0.01),clinical pregnancy(49.5%and 31.2%,P<0.01),live birth(43.1%and 25.7%,P<0.01),and fetal heart rates(50.0%and 29.8%,P<0.01)per transfer were significantly higher in the RIF-PGT-A group.Conclusion:Elective single-embryo transfer PGT-A can minimize the risk of obstetric and perinatal outcomes,especially fetal body weight,in women with RIF.Additionally,PGT-A can significantly improve pregnancy and live birth rates.展开更多
目的评估宫腔灌注富血小板血浆(PRP)对反复种植失败(RIF)妇女妊娠结局的影响。方法使用PubMed、Embase、Scopus、Web of Science、CochraneLibrary、中国知识基础设施工程、维普数据库、万方数据库,检索PRP宫腔灌注治疗RIF患者的临床研...目的评估宫腔灌注富血小板血浆(PRP)对反复种植失败(RIF)妇女妊娠结局的影响。方法使用PubMed、Embase、Scopus、Web of Science、CochraneLibrary、中国知识基础设施工程、维普数据库、万方数据库,检索PRP宫腔灌注治疗RIF患者的临床研究。提取数据后使用固定效应模型或随机效应模型进行Meta分析。结果共纳入7项研究。接受PRP宫腔灌注女性的生化妊娠率[OR=2.18,95%CI:[1.34,3.52],P<0.05]、临床妊娠率(OR=2.47,95%CI:[1.66,3.68],P<0.05)、活产率(OR=5.00,95%CI:[1.09,22.99],P<0.05)和胚胎种植率(OR=1.99,95%CI:[1.36,2.93],P<0.05)高于对照组,流产率低于对照组(OR=0.28,95%CI:[0.10,0.77],P<0.05)。亚组分析显示宫腔灌注0.5 mL PRP组的临床妊娠率高于宫腔灌注1.0 mL PRP组(P<0.05),流产率低于宫腔灌注1.0 mL PRP组(P<0.05)。结论宫腔灌注PRP可提高RIF患者的胚胎种植率、活产率、生化妊娠率和临床妊娠率,且显著降低流产的风险,宫腔灌注0.5 mL PRP具有更好的临床效果。展开更多
基金Supported by the National Natural Science Foundation of China(41072213 and 40801212)the Opening Fund of Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University(201207)
文摘The paper attempts to represent a case of repeated failures on a high cut slope due to multi-excavation. The characteristics of each failure induced by excavation are analyzed through geological investigation, and then a geological model at different failure stages is proposed. The geological analysis shows that the excavation-induced repeated failures are related to the exposure of the weak bedding plane and the toe unloading of the cut slope, Numerical modeling is conducted based on a sequential method, taking into account the main failure stages of cut slope. The simulation results fairly coincide with the practical phenomena observed in field. It is shown that the decrease in normal stress of displaced mass on cut slope will induce the increase in shear stress in bedding planes and that at the toe of the cut slope. The released stress leads to repeated gravitational instabilities of cut slope due to the decrease in normal stress and the increase in shear stress along the bedding planes of mudstone.
基金supported by grants from the National Natural Science Foundation of China(No.81100401 and No.81470063)Guangdong Natural Science Foundation of China(No.2014A030313129)the Doctoral Fund of the Ministry of Education of China(No.20110171120096)
文摘Long-term gonadotropin-releasing hormone agonist（Gn RHa） administration before in vitro fertilization（IVF）/intracytoplasmic sperm injection（ICSI） in infertile women with endometriosis or adenomyosis significantly enhanced the chances of pregnancy in both fresh and frozen embryo transfer cycles. We hypothesized that long-term Gn RHa treatment might also be beneficial for the idiopathic repeated implantation failure（RIF） patients. In the 21 patients receiving Gn RHa and hormone replacement therapy（G-HRT） protocols for frozen embryo transfer, their data were compared with those of the 56 of frozen/fresh cycles they had previously undergone（previous protocols）. Comparison showed that the finial results were significantly better with G-HRT protocols than with their previous protocols, with pregnancy rate, clinical pregnancy rate, implantation rate and on-going pregnancy rate being 70%, 60%, 40% and 38% respectively with G-HRT protocols, against 17%, 11%, 6.3% and 5% with previous protocols. The results showed that hormonally controlled endometrial preparation with prior Gn RHa suppression could be used for patients who had experienced repeated failures of IVF treatment despite having morphologically optimal embryos, and the treatment may help increase the receptivity of the endometrium in these patients.
文摘Using self-made impact fatigue test instruments and related analytic devices,the mechanical components with laser cladding layer have been attempted. It is found that, onrepeated impact force, several failure modes of the components include the surface cracks, surfaceplastic deformation, corrosive pitting and coat collapse, etc. The paper reported the test methodand initial analysis conclusions about the unique failure characteristics of the mechanicalcomponents on repeated impact load.
文摘Objective\ The relationship between graft blood flow, epicardial microflow, mean arterial pressure and hemorheologic changes was studied during intraoperative heart failure. Methods\ These parameters were done to evaluate the use of repeated cardiopulmonary bypass support for the intraoperative heart failure following aorto coronary bypass surgery. Included in this study were 10 patients with a mean age of 70 and unstable angina undergoing coronary bypass grafting and suffering from intraoperative heart failure. The epicardiai microflow, graft flow, mean arterial pressure and blood cell filterability were measured. Resluts\ During heart failure, the mean arterial pressure fell by 41%(P<0.01), graft flow by 67%(P<0.01) and epicardialmicroflow by 64%(P<0.01). After 15 to 56 min of assisted cardiopulmonary bypass support, the epicardial microflow and graft flow were partially restored, while red cell and white cell filterability was reduced by 31% and 64% respectively (P<0.01). There were significant correlations between graft flow, epicardial microflow, blood cell filterability and cardiopulmonary bypass time. All patients recovered and were discharged from the hospital.Conclusion\ It is concluded that the use of temporary assisted CPB support to treat intrapoperative heart failure allows the recovery of the myocardium and thereby restores the mean arterial pressure. The recovery of graft flow and epicardial flow occurred to a lesser extent. The CPB support seemed to be suitable for about 60 min probably because of increasing disturbance to the blood cell filterability, graft flow and the epicardial microcirculation.\;
文摘Often in longitudinal studies, some subjects complete their follow-up visits, but others miss their visits due to various reasons. For those who miss follow-up visits, some of them might learn that the event of interest has already happened when they come back. In this case, not only are their event times interval-censored, but also their time-dependent measurements are incomplete. This problem was motivated by a national longitudinal survey of youth data. Maximum likelihood estimation (MLE) method based on expectation-maximization (EM) algorithm is used for parameter estimation. Then missing information principle is applied to estimate the variance-covariance matrix of the MLEs. Simulation studies demonstrate that the proposed method works well in terms of bias, standard error, and power for samples of moderate size. The national longitudinal survey of youth 1997 (NLSY97) data is analyzed for illustration.
基金National Natural Science Foundation of China(No.81901558)
文摘Objective:The objective of this study is to study whether preimplantation genetic testing for aneuploidy(PGT-A)improves the clinical outcomes of infertile patients with repeated implantation failure(RIF)undergoing frozen-thawed embryo transfer.Methods:This is a retrospective analysis of clinical pregnancy,live birth,miscarriage rates,and obstetric and perinatal outcomes of women with RIF with or without PGT-A.Statistical analyses of categorical data were performed using propensity score matching(PSM),χ^(2)test,and Student’s t test.Results:We enrolled 466 patients with RIF,of which,209 were in the RIF-PGT-A group.The rate of euploid blastocysts was significantly associated with age and day 5 or 6 blastocysts.There were significant differences between the RIF-PGT-A group and the RIF-non-PGT-A group across several parameters.After PSM,positive serum human chorionic gonadotropin(56.9%and 33.9%,P<0.01),clinical pregnancy(49.5%and 31.2%,P<0.01),live birth(43.1%and 25.7%,P<0.01),and fetal heart rates(50.0%and 29.8%,P<0.01)per transfer were significantly higher in the RIF-PGT-A group.Conclusion:Elective single-embryo transfer PGT-A can minimize the risk of obstetric and perinatal outcomes,especially fetal body weight,in women with RIF.Additionally,PGT-A can significantly improve pregnancy and live birth rates.
文摘目的评估宫腔灌注富血小板血浆(PRP)对反复种植失败(RIF)妇女妊娠结局的影响。方法使用PubMed、Embase、Scopus、Web of Science、CochraneLibrary、中国知识基础设施工程、维普数据库、万方数据库,检索PRP宫腔灌注治疗RIF患者的临床研究。提取数据后使用固定效应模型或随机效应模型进行Meta分析。结果共纳入7项研究。接受PRP宫腔灌注女性的生化妊娠率[OR=2.18,95%CI:[1.34,3.52],P<0.05]、临床妊娠率(OR=2.47,95%CI:[1.66,3.68],P<0.05)、活产率(OR=5.00,95%CI:[1.09,22.99],P<0.05)和胚胎种植率(OR=1.99,95%CI:[1.36,2.93],P<0.05)高于对照组,流产率低于对照组(OR=0.28,95%CI:[0.10,0.77],P<0.05)。亚组分析显示宫腔灌注0.5 mL PRP组的临床妊娠率高于宫腔灌注1.0 mL PRP组(P<0.05),流产率低于宫腔灌注1.0 mL PRP组(P<0.05)。结论宫腔灌注PRP可提高RIF患者的胚胎种植率、活产率、生化妊娠率和临床妊娠率,且显著降低流产的风险,宫腔灌注0.5 mL PRP具有更好的临床效果。
