为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点...为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点最佳经济产量施肥量,最终建立了关中灌区冬小麦基于土壤碱解氮(AN)、有效磷(AP)和速效钾(AK)测定值的氮、磷、钾推荐施肥模型,确定了不同肥力水平下的推荐施肥量:当碱解氮含量处于极低(<50 mg kg-1)、低(50～80 mg kg-1)、中(80～120 mg kg-1)和高等级(>120 mg kg-1)时,氮肥(N)施用量分别为190～230 kg hm-2、150～190 kg hm-2、110～150 kg hm-2和0～110 kg hm-2;有效磷含量处于极低(<10 mg kg-1)、低(10～20 mg kg-1)、中(20～35 mg kg-1)和高等级(>35 mg kg-1)时,磷肥(P2O5)施用量分别为130～160 kg hm-2、110～130 kg hm-2、90～110 kg hm-2和0～90 kg hm-2;速效钾含量处于低(<90 mg kg-1)、中(90～150 mg kg-1)、高(150～190 mg kg-1)和极高等级(>190 mg kg-1)时,钾肥(K2O)施用量分别为120～150 kg hm-2、90～120 kg hm-2、70～90 kg hm-2和0～70 kg hm-2。示范试验证明推荐施肥处理较农民习惯施肥处理平均增产789 kg hm-2,增收1 227元hm-2,肥料贡献率提高8.2个百分点,每kg氮磷钾肥小麦增产量提高1.7 kg。展开更多
Objective: To investigate the effects of body mass index(BMI) on the outcomes of in vitro fertilization(IVF) in Chinese patients with polycystic ovary syndrome(PCOS). Methods: In the retrospective cohort study, a tota...Objective: To investigate the effects of body mass index(BMI) on the outcomes of in vitro fertilization(IVF) in Chinese patients with polycystic ovary syndrome(PCOS). Methods: In the retrospective cohort study, a total of 1074 patients with PCOS undergoing IVF between April 2010 and May 2017 in two reproductive medicine centers, respectively in eastern China(Women's Hospital, School of Medicine, Zhejiang University, Zhejiang Province) and in southern China(Maternal and Child Health Care Hospital of Liuzhou, Guangxi Province), were included. The patients were divided into four groups according to the recommended Chinese BMI cut-off points: underweight(BMI<18.5kg/m^2), normal weight(18.5kg/m^2≤BMI<24.0kg/m^2), overweight(24.0kg/m^2≤BMI<28.0kg/m^2), and obese(BMI≥28.0kg/m2). The basic characteristics of the PCOS patients, the details of IVF treatment, and the pregnancy outcomes were collected. Main results: There were no significant differences among the normal weight, overweight, and obese PCOS patients undergoing IVF on the biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, or term delivery rate(P>0.05), although the overweight and obese PCOS patients required more gonadotropin(Gn)(P<0.001) as well as longer stimulation period(P<0.001), and got less retrieved oocytes(P<0.05) and fertilized oocytes(P<0.05). The underweight PCOS patients required less Gn(P<0.05) and achieved higher live birth rate and term delivery rate(P<0.05), compared with the normal weight PCOS patients. Conclusions: High BMI had no negative effects on the outcomes of IVF in Chinese patients with PCOS; however, the conclusion may seem a little limited due to the retrospective design and the potential bias.展开更多
Background:High body mass index(BMI)results in decreased fecundity,and women with high BMI have reduced rates of clinical pregnancy and live birth in in vitro fertilization/intra-cytoplasmic sperm injection(IVF/ICSI)....Background:High body mass index(BMI)results in decreased fecundity,and women with high BMI have reduced rates of clinical pregnancy and live birth in in vitro fertilization/intra-cytoplasmic sperm injection(IVF/ICSI).Meanwhile,ovarian responses show great heterogeneity in patients with a high BMI.This study aimed to analyze the effects of a high BMI on IVF/ICSI outcomes in the Chinese female with normal ovarian response.Methods:We performed a retrospective cohort study comprising 15,124 patients from the medical record system of the Reproductive Center of Peking University Third Hospital,with 3530(23.3%)in the overweight group and 1380(9.1%)in the obese group,who had a normal ovarian response(5-15 oocytes retrieved)and underwent fresh embryo transfer(ET)cycles from January 2017 to December 2018,followed by linked frozen-thawed embryo transfer(FET)cycles from January 2017 to December 2020.Cumulative live birth rate(CLBR)was used as the primary outcome.Furthermore,a generalized additive model was applied to visually illustrate the curvilinear relationship between BMI and the outcomes.We used a decision tree to identify the specific population where high BMI had the greatest effect on IVF/ICSI outcomes.Results:High BMI was associated with poor IVF/ICSI outcomes,both in cumulative cycles and in separate fresh ET or FET cycles.In cumulative cycles,compared with the normal weight group,obesity was correlated with a lower positive pregnancy test rate(adjusted odds ratio[aOR]:0.809,95%confidence interval[CI]:0.682-0.960),lower clinical pregnancy rate(aOR:0.766,95%CI:0.646-0.907),lower live birth rate(aOR:0.706,95%CI:0.595-0.838),higher cesarean section rate(aOR:2.066,95%CI:1.533-2.785),and higher rate of large for gestational age(aOR:2.273,95%CI:1.547-3.341).In the generalized additive model,we found that CLBR declined with increasing BMI,with 24 kg/m^(2)as an inflection point.In the decision tree,BMI only made a difference in the population aged≤34.5 years,with anti-Mullerian hormone>1.395 ng/mL,and the first time for展开更多
文摘为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点最佳经济产量施肥量,最终建立了关中灌区冬小麦基于土壤碱解氮(AN)、有效磷(AP)和速效钾(AK)测定值的氮、磷、钾推荐施肥模型,确定了不同肥力水平下的推荐施肥量:当碱解氮含量处于极低(<50 mg kg-1)、低(50～80 mg kg-1)、中(80～120 mg kg-1)和高等级(>120 mg kg-1)时,氮肥(N)施用量分别为190～230 kg hm-2、150～190 kg hm-2、110～150 kg hm-2和0～110 kg hm-2;有效磷含量处于极低(<10 mg kg-1)、低(10～20 mg kg-1)、中(20～35 mg kg-1)和高等级(>35 mg kg-1)时,磷肥(P2O5)施用量分别为130～160 kg hm-2、110～130 kg hm-2、90～110 kg hm-2和0～90 kg hm-2;速效钾含量处于低(<90 mg kg-1)、中(90～150 mg kg-1)、高(150～190 mg kg-1)和极高等级(>190 mg kg-1)时,钾肥(K2O)施用量分别为120～150 kg hm-2、90～120 kg hm-2、70～90 kg hm-2和0～70 kg hm-2。示范试验证明推荐施肥处理较农民习惯施肥处理平均增产789 kg hm-2,增收1 227元hm-2,肥料贡献率提高8.2个百分点,每kg氮磷钾肥小麦增产量提高1.7 kg。
基金Project supported by the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(No.LR16H040001)the Key Project of Science and Technology Department of Zhejiang Province(No.2018C03010)+2 种基金the Zhejiang Provincial&Ministry of Health Research Fund for Medical Sciences(Nos.WKJ-ZJ-1522 and WKJ-ZJ-1722)the National Key Technology R&D Program of China(No.2014BAI05B04)the Guangxi Natural Science Foundation(Nos.2015GXNSFBA139177,2017GXNSFAA198199,and 2017GXNSFAA198193),China
文摘Objective: To investigate the effects of body mass index(BMI) on the outcomes of in vitro fertilization(IVF) in Chinese patients with polycystic ovary syndrome(PCOS). Methods: In the retrospective cohort study, a total of 1074 patients with PCOS undergoing IVF between April 2010 and May 2017 in two reproductive medicine centers, respectively in eastern China(Women's Hospital, School of Medicine, Zhejiang University, Zhejiang Province) and in southern China(Maternal and Child Health Care Hospital of Liuzhou, Guangxi Province), were included. The patients were divided into four groups according to the recommended Chinese BMI cut-off points: underweight(BMI<18.5kg/m^2), normal weight(18.5kg/m^2≤BMI<24.0kg/m^2), overweight(24.0kg/m^2≤BMI<28.0kg/m^2), and obese(BMI≥28.0kg/m2). The basic characteristics of the PCOS patients, the details of IVF treatment, and the pregnancy outcomes were collected. Main results: There were no significant differences among the normal weight, overweight, and obese PCOS patients undergoing IVF on the biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, or term delivery rate(P>0.05), although the overweight and obese PCOS patients required more gonadotropin(Gn)(P<0.001) as well as longer stimulation period(P<0.001), and got less retrieved oocytes(P<0.05) and fertilized oocytes(P<0.05). The underweight PCOS patients required less Gn(P<0.05) and achieved higher live birth rate and term delivery rate(P<0.05), compared with the normal weight PCOS patients. Conclusions: High BMI had no negative effects on the outcomes of IVF in Chinese patients with PCOS; however, the conclusion may seem a little limited due to the retrospective design and the potential bias.
基金National Key Research and Development Program of China(No.2021YFC2700601)National Science Fund for Distinguished Young Scholars(No.81925013)
文摘Background:High body mass index(BMI)results in decreased fecundity,and women with high BMI have reduced rates of clinical pregnancy and live birth in in vitro fertilization/intra-cytoplasmic sperm injection(IVF/ICSI).Meanwhile,ovarian responses show great heterogeneity in patients with a high BMI.This study aimed to analyze the effects of a high BMI on IVF/ICSI outcomes in the Chinese female with normal ovarian response.Methods:We performed a retrospective cohort study comprising 15,124 patients from the medical record system of the Reproductive Center of Peking University Third Hospital,with 3530(23.3%)in the overweight group and 1380(9.1%)in the obese group,who had a normal ovarian response(5-15 oocytes retrieved)and underwent fresh embryo transfer(ET)cycles from January 2017 to December 2018,followed by linked frozen-thawed embryo transfer(FET)cycles from January 2017 to December 2020.Cumulative live birth rate(CLBR)was used as the primary outcome.Furthermore,a generalized additive model was applied to visually illustrate the curvilinear relationship between BMI and the outcomes.We used a decision tree to identify the specific population where high BMI had the greatest effect on IVF/ICSI outcomes.Results:High BMI was associated with poor IVF/ICSI outcomes,both in cumulative cycles and in separate fresh ET or FET cycles.In cumulative cycles,compared with the normal weight group,obesity was correlated with a lower positive pregnancy test rate(adjusted odds ratio[aOR]:0.809,95%confidence interval[CI]:0.682-0.960),lower clinical pregnancy rate(aOR:0.766,95%CI:0.646-0.907),lower live birth rate(aOR:0.706,95%CI:0.595-0.838),higher cesarean section rate(aOR:2.066,95%CI:1.533-2.785),and higher rate of large for gestational age(aOR:2.273,95%CI:1.547-3.341).In the generalized additive model,we found that CLBR declined with increasing BMI,with 24 kg/m^(2)as an inflection point.In the decision tree,BMI only made a difference in the population aged≤34.5 years,with anti-Mullerian hormone>1.395 ng/mL,and the first time for
