目的系统评价初潮年龄以及术后妊娠分娩次数与子宫肌瘤剔除术后复发关系。方法计算机检索中国知网(CNKI)、万方、维普、中国生物医学文献数据库、Pubmed数据库、Google scholar、Cochrane library和Web of Science数据库中关于初潮年龄...目的系统评价初潮年龄以及术后妊娠分娩次数与子宫肌瘤剔除术后复发关系。方法计算机检索中国知网(CNKI)、万方、维普、中国生物医学文献数据库、Pubmed数据库、Google scholar、Cochrane library和Web of Science数据库中关于初潮年龄、术后妊娠分娩次数与女性子宫肌瘤剔除术后复发危险关系的队列研究,检索时间为建库时间至2016-07-01。按照纳入排除标准筛选文献后提取数据,并按照NOS队列研究质量评价标准进行纳入文献质量评价,使用Stata12.0软件进行统计分析。结果最终27篇文献包括5492例病例纳入研究。初潮年龄<13岁(RR=1.53,95%CI=1.15~2.04)和术后未分娩(RR=1.63,95%CI=1.30~2.03)是术后复发的危险因素;初潮年龄低于14岁(RR=1.23,95%CI=0.86~1.75)和术后妊娠(RR=1.01,95%CI=0.79~1.29)对复发风险无显著影响,按照文献来源进行亚组分析(中文:RR=0.90,95%CI=0.70~1.15;英文:RR=1.39,95%CI=0.74~2.58)也没有发现显著关联。结论初潮年龄<13岁和术后未分娩是子宫肌瘤术后复发的危险因素。展开更多
The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitiv...The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitive edge,the collaborative routing of drones in the air and trucks on the ground is increasingly invested in the next generation of delivery,where it is particularly reasonable to consider customer time windows and time-dependent travel times as two typical time-related factors in daily services.In this paper,we propose the Vehicle Routing Problem with Drones under Time constraints(VRPD-T)and focus on the time constraints involved in realistic scenarios during the delivery.A mixed-integer linear programming model has been developed to minimize the total delivery completion time.Furthermore,to overcome the limitations of standard solvers in handling large-scale complex issues,a space-time hybrid heuristic-based algorithm has been developed to effectively identify a high-quality solution.The numerical results produced from randomly generated instances demonstrate the effectiveness of the proposed algorithm.展开更多
外卖O2O(Online to Offline)是一种典型的移动互联网商业模式。入驻外卖O2O平台的餐饮企业为增强顾客的配送满意度,需要对其配送服务进行规划设计。文章研究外卖O2O平台上饮食类供应商外卖配送中的车辆路径问题(VRP),通过对外卖配送特...外卖O2O(Online to Offline)是一种典型的移动互联网商业模式。入驻外卖O2O平台的餐饮企业为增强顾客的配送满意度,需要对其配送服务进行规划设计。文章研究外卖O2O平台上饮食类供应商外卖配送中的车辆路径问题(VRP),通过对外卖配送特点的深入分析,采用模拟方法实现了随机旅行时间分布的准确刻画,以最大化顾客满意度为目标,综合考虑配送过程中的约束要求,建立了随机旅行时间的带顾客需求时间窗的VRP问题的数学模型。基于上海市徐汇区某入驻外卖O2O企业配送服务的算例,利用遗传算法完成求解。结果显示本文算法可以有效计算出响应顾客需求的最优车辆路径,分析了顾客完全满意度区间大小、顾客满意度敏感性以及配送车辆数量等因素对配送方案总体满意度水平的影响,提出了提高外卖O2O配送满意度的建议。并针对外卖O2O商户自负配送模式进行了研究,可为外卖O2O平台上饮食类供应商改善配送和提升顾客满意度提供决策支持。展开更多
Background and Objective: Although globally admitted as the most valuable tool to prevent prolongation of labor, the partogram has failed to be commonly used. This is due to its alleged complexity. Based on the simpli...Background and Objective: Although globally admitted as the most valuable tool to prevent prolongation of labor, the partogram has failed to be commonly used. This is due to its alleged complexity. Based on the simplified model proposed by Debdas, the so called paperless partogram, we aimed at evaluating the ability of only using the alert and action lines to prevent prolongation of labor. Methods: This was a cross-sectional study including labor records of women delivered at King Baudouin Hospital of Kinshasa (secondary level) from 01/01 till 31/12/2013. The study was approved by the Faculty Ethical Committee. Inclusion criteria were: 1) live singleton pregnancy, 2) cephalic fetal presentation, 3) lack of uterine scar, 4) monitoring in labor ward by 4 cm of cervical dilation, and 5) delivery at term. For every record, the expected time of delivery (ETD = 6 hours after 4 cm of cervical dilation) was considered “Alert EDT” to which 4 hours were added to obtain the “Action EDT”. Irrespective of other fetal and maternal features contained in the traditional partogram Alert and Action ETD were checked a posteriori on Debdas’s model to derive the appropriate outcome of labor. Results: The study included 357 participants, of which 219 primiparous and 138 multiparous. Vaginal delivery took place in 91% of cases. Full cervical dilation was achieved after 8 - 9 hours (9.5 ± 1.8 hours for primiparous and 8.4 ± 1.7 hours for multiparous women), namely 2 - 3 hours following Alert ETD). This duration is close to the Action ETD. For 32 cesarean sections (9%) final decision took place within the Alert ETD. Conclusion: Using only Alert and Action ETD was found convenient to derive appropriate measures for the outcome of labor. So, the paperless partogram is a simplified method to manage the active stage of labor that could prevent prolongation of labor in our setting.展开更多
文摘目的系统评价初潮年龄以及术后妊娠分娩次数与子宫肌瘤剔除术后复发关系。方法计算机检索中国知网(CNKI)、万方、维普、中国生物医学文献数据库、Pubmed数据库、Google scholar、Cochrane library和Web of Science数据库中关于初潮年龄、术后妊娠分娩次数与女性子宫肌瘤剔除术后复发危险关系的队列研究,检索时间为建库时间至2016-07-01。按照纳入排除标准筛选文献后提取数据,并按照NOS队列研究质量评价标准进行纳入文献质量评价,使用Stata12.0软件进行统计分析。结果最终27篇文献包括5492例病例纳入研究。初潮年龄<13岁(RR=1.53,95%CI=1.15~2.04)和术后未分娩(RR=1.63,95%CI=1.30~2.03)是术后复发的危险因素;初潮年龄低于14岁(RR=1.23,95%CI=0.86~1.75)和术后妊娠(RR=1.01,95%CI=0.79~1.29)对复发风险无显著影响,按照文献来源进行亚组分析(中文:RR=0.90,95%CI=0.70~1.15;英文:RR=1.39,95%CI=0.74~2.58)也没有发现显著关联。结论初潮年龄<13岁和术后未分娩是子宫肌瘤术后复发的危险因素。
基金supported by the National Natural Science Foundation of China(No.61961146005)。
文摘The advancement of autonomous technology makes electric-powered drones an excellent choice for flexible logistics services at the last mile delivery stage.To reach a balance between green transportation and competitive edge,the collaborative routing of drones in the air and trucks on the ground is increasingly invested in the next generation of delivery,where it is particularly reasonable to consider customer time windows and time-dependent travel times as two typical time-related factors in daily services.In this paper,we propose the Vehicle Routing Problem with Drones under Time constraints(VRPD-T)and focus on the time constraints involved in realistic scenarios during the delivery.A mixed-integer linear programming model has been developed to minimize the total delivery completion time.Furthermore,to overcome the limitations of standard solvers in handling large-scale complex issues,a space-time hybrid heuristic-based algorithm has been developed to effectively identify a high-quality solution.The numerical results produced from randomly generated instances demonstrate the effectiveness of the proposed algorithm.
文摘外卖O2O(Online to Offline)是一种典型的移动互联网商业模式。入驻外卖O2O平台的餐饮企业为增强顾客的配送满意度,需要对其配送服务进行规划设计。文章研究外卖O2O平台上饮食类供应商外卖配送中的车辆路径问题(VRP),通过对外卖配送特点的深入分析,采用模拟方法实现了随机旅行时间分布的准确刻画,以最大化顾客满意度为目标,综合考虑配送过程中的约束要求,建立了随机旅行时间的带顾客需求时间窗的VRP问题的数学模型。基于上海市徐汇区某入驻外卖O2O企业配送服务的算例,利用遗传算法完成求解。结果显示本文算法可以有效计算出响应顾客需求的最优车辆路径,分析了顾客完全满意度区间大小、顾客满意度敏感性以及配送车辆数量等因素对配送方案总体满意度水平的影响,提出了提高外卖O2O配送满意度的建议。并针对外卖O2O商户自负配送模式进行了研究,可为外卖O2O平台上饮食类供应商改善配送和提升顾客满意度提供决策支持。
文摘Background and Objective: Although globally admitted as the most valuable tool to prevent prolongation of labor, the partogram has failed to be commonly used. This is due to its alleged complexity. Based on the simplified model proposed by Debdas, the so called paperless partogram, we aimed at evaluating the ability of only using the alert and action lines to prevent prolongation of labor. Methods: This was a cross-sectional study including labor records of women delivered at King Baudouin Hospital of Kinshasa (secondary level) from 01/01 till 31/12/2013. The study was approved by the Faculty Ethical Committee. Inclusion criteria were: 1) live singleton pregnancy, 2) cephalic fetal presentation, 3) lack of uterine scar, 4) monitoring in labor ward by 4 cm of cervical dilation, and 5) delivery at term. For every record, the expected time of delivery (ETD = 6 hours after 4 cm of cervical dilation) was considered “Alert EDT” to which 4 hours were added to obtain the “Action EDT”. Irrespective of other fetal and maternal features contained in the traditional partogram Alert and Action ETD were checked a posteriori on Debdas’s model to derive the appropriate outcome of labor. Results: The study included 357 participants, of which 219 primiparous and 138 multiparous. Vaginal delivery took place in 91% of cases. Full cervical dilation was achieved after 8 - 9 hours (9.5 ± 1.8 hours for primiparous and 8.4 ± 1.7 hours for multiparous women), namely 2 - 3 hours following Alert ETD). This duration is close to the Action ETD. For 32 cesarean sections (9%) final decision took place within the Alert ETD. Conclusion: Using only Alert and Action ETD was found convenient to derive appropriate measures for the outcome of labor. So, the paperless partogram is a simplified method to manage the active stage of labor that could prevent prolongation of labor in our setting.
