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Prevalence and risk factors of infertility in a Mongolian population
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作者 Tuvshinbayar Negdel Arigbukh Enkhbat +8 位作者 Badrakh Munkhbayar Khantushig Bilegsuren Ariunaa Ganbold Khuderchuluun Nanjid Carol W Readhead Lkhagva-Ochir Erkhembaatar Erkhembaatar Tuduvdorj Munkhzol Malchinkhuu Odkhuu Enkhtaivan 《Asian pacific Journal of Reproduction》 2023年第3期109-116,共8页
Objective:To investigate and analyze the prevalence and risk factors of infertility in a Mongolian population.Methods:We conducted a population-based cross-sectional study between September 2016 and November 2021.Our ... Objective:To investigate and analyze the prevalence and risk factors of infertility in a Mongolian population.Methods:We conducted a population-based cross-sectional study between September 2016 and November 2021.Our study population of 1919 participants consisted of residents of Ulaanbaatar city and four regions of Mongolia.A pretested standardized and structured questionnaire was used to gather data from the participants.Our questionnaire comprised categories influencing infertility,such as socioeconomic status,lifestyle factors,health,reproductive history,present status,and sexual function.In addition,trained staff conducted face-to-face interviews with the participants.Results:Our study showed an infertility incidence of 8.2%,with primary infertility at 2.76%and secondary infertility at 5.47%.Compared with the urban area of Ulaanbaatar,the prevalence of infertility was significantly higher amongst the rural population(P<0.001).Risk factors of infertility included advanced age(35-39 years,OR 1.8,95%CI 1.99-6.55;>40 years,OR 2.1,95%CI 2.62-8.55),living rural region(aOR 2.4,95%CI 1.62-3.69),alcohol consumption(aOR 1.6,95%CI 1.11-2.44),chronic diseases(aOR 1.6,95%CI 1.20-2.38),reproductive disease(aOR 2.6,95%CI 1.86-3.88),gynecological operative history(aOR 2.1,95%CI 1.38-3.21),ovarian cyst(aOR 4.2,95%CI 2.70-6.40),gonorrhea(aOR 2.4,95%CI 1.01-6.16),non-malignant uterine cancer(aOR 2.9,95%CI 1.40-6.70),and endometriosis(aOR 4.7,95%CI 1.41-15.62).Conclusions:In Mongolia,the average infertility rate is 8.2%,similar to the average worldwide and is significantly higher in rural communities.Our study shows the most significant risk factors for infertility are age,alcohol consumption,and rural living.In addition,an unfavorable gynecological history and some diseases also pose a risk to fertility. 展开更多
关键词 INFERTILITY Risk factors Prevalence Region Primary infertility Secondary infertility Reproductive health Age
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条形荷载下加筋土边坡破坏机制的数值模拟 被引量:10
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作者 高文华 Richard J.Bathurst 《土木工程学报》 EI CSCD 北大核心 2007年第6期54-58,共5页
为了克服模型的尺寸效用,获得加筋与不加筋边坡在条形荷载下的各种性状参数和边坡的破坏机制,建立用于分析和模拟3个大型室内足尺加筋与不加筋边坡破坏机制的数值计算模型。边坡回填材料采用级配较差的粗砂,土体的非线性弹性响应采用Dun... 为了克服模型的尺寸效用,获得加筋与不加筋边坡在条形荷载下的各种性状参数和边坡的破坏机制,建立用于分析和模拟3个大型室内足尺加筋与不加筋边坡破坏机制的数值计算模型。边坡回填材料采用级配较差的粗砂,土体的非线性弹性响应采用Duncan-Chang双曲线模型E-B模式加以描述,破坏准则采用Mohr-Coulomb屈服准则,并采用与屈服条件不相关联的流动法则。加筋材料采用两节点的弹塑性锚索结构单元进行模拟,并采用无厚度的弹簧-滑动系统来模拟筋土之间的相互作用和相对运动。数值计算采用基于有限差分的连续介质快速拉格朗日分析方法(FLAC),分别对与破坏面位置和形态密切相关的节点位移速度向量、塑性区和剪应变速率分布3个参数进行了计算,获得了3个边坡在条形极限荷载下的双楔体破坏机制和极限承载力,与试验结果吻合较好,验证了模型的可行性。在此基础上,对不同的条形荷载位置及不同填土材料强度下边坡破坏机制进行了数值模拟和分析。研究结果表明,无论加筋与不加筋边坡,当条形荷载位置距坡肩的距离减小时,边坡破坏面形态由双楔体过渡到圆弧形;当填土材料强度降低时,破裂面形态转化为圆弧形或对数螺线形。 展开更多
关键词 边坡 破坏机制 土工格栅 条形荷载 FLAC
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土工格栅加筋边坡坡顶条基极限荷载的预测 被引量:6
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作者 陶连金 Richard J.Bathurst 《土木工程学报》 EI CSCD 北大核心 2005年第7期107-111,共5页
通过土工合成材料加固的边坡,承载能力显著提高,因而获得广泛应用。为了合理的评价加筋边坡的坡顶条形基础的极限荷载,制作了足尺寸模型并进行了试验,采用延性较好但强度较低的聚丙烯(PP)土工格栅对边坡进行了加固,在坡顶通过条形基础(... 通过土工合成材料加固的边坡,承载能力显著提高,因而获得广泛应用。为了合理的评价加筋边坡的坡顶条形基础的极限荷载,制作了足尺寸模型并进行了试验,采用延性较好但强度较低的聚丙烯(PP)土工格栅对边坡进行了加固,在坡顶通过条形基础(钢梁)施加荷载直至边坡破坏,获得了极限荷载以及边坡的变形和破坏规律,通过细致的测试手段,详细地捕捉到模型的力学响应。在此基础上,通过校验的FLAC数值模型,对土工格栅加筋边坡的承载能力进行了预测,得到了满意的结果。 展开更多
关键词 土工格栅 边坡 数值模拟 极限荷载
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加筋边坡在坡顶荷载作用下的极限承载能力 被引量:23
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作者 Richard Bathurst 陶连金 《岩土工程学报》 EI CAS CSCD 北大核心 2004年第2期194-197,共4页
采用大型室内试验的方法,研究了两个土工格栅加固的土坡和一个未加固边坡在坡顶荷载作用下的变形与破坏规律。本文重点介绍大型模型的实验设计、测试技术和研究方法。实验结果表明,土工格栅加固边坡的承载能力为相同条件下未加固边坡的1... 采用大型室内试验的方法,研究了两个土工格栅加固的土坡和一个未加固边坡在坡顶荷载作用下的变形与破坏规律。本文重点介绍大型模型的实验设计、测试技术和研究方法。实验结果表明,土工格栅加固边坡的承载能力为相同条件下未加固边坡的1.6-2倍。 展开更多
关键词 土工格栅 极限承载力 模型试验 加筋 边坡 坡顶荷载
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Sperm chromatin structure assay (SCSA): a tool in diagnosis and treatment of infertility 被引量:35
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作者 Mona Bungum Leif Bungum Aleksander Giwercman 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第1期69-75,共7页
Diagnosis of male infertility has mainly been based on the World Health Organization (WHO) manual-based semen parameter's concentration, motility and morphology. It has, however, become apparent that none of these ... Diagnosis of male infertility has mainly been based on the World Health Organization (WHO) manual-based semen parameter's concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay (SCSA), a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection (ICSI). 展开更多
关键词 assisted reproductive techniques INFERTILITY sperm chromatin structure assay sperm DNA
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General Conditions for Online Estimation and Optimization of Reliability Characteristics 被引量:1
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作者 Ilona Pabst Peter C. Müller 《International Journal of Automation and computing》 EI 2006年第2期177-183,共7页
A novel approach to estimate reliability properties of systems or components individually during operation is presented. It is distinguished between slow and fast reliability states based on an equivalent system repre... A novel approach to estimate reliability properties of systems or components individually during operation is presented. It is distinguished between slow and fast reliability states based on an equivalent system representation. Conditions for their observability and control are given and objectives for optimal reliability-based control are discussed in general. 展开更多
关键词 Online reliability estimation reliability optimization singular systems
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常规连锁超市业态诉求与管理模式解决方案透析 被引量:1
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作者 刘文烽 《中国商贸》 2001年第6期12-15,共4页
关键词 超级市场 连锁经营 管理模式 目标客层
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金属推型V带无级变速箱损耗机理仿真 部分3:带的滑动损失
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作者 S.Akehurst N.D.Vaughan +2 位作者 D.A.Parker D.Simner 介眉 《传动技术》 2006年第2期33-43,共11页
大家已经知道,以推型金属带为基件的无级变速箱(CVTs)的传动效率低于速比间断变化的变速器这种倾向是用CVT由于发动机/负荷匹配得到的燃油经济性的好处有被抵消的趋势。本论文组三篇论文详细地阐述了作为第一级得到的改进效率的带传动... 大家已经知道,以推型金属带为基件的无级变速箱(CVTs)的传动效率低于速比间断变化的变速器这种倾向是用CVT由于发动机/负荷匹配得到的燃油经济性的好处有被抵消的趋势。本论文组三篇论文详细地阐述了作为第一级得到的改进效率的带传动中损耗机理的研究。接上述两篇论文本文对由于带组和带的推块之间的相对运动以及带轮和带由于带轮变形的影响发生转矩损失进行模拟分析。本文还描述了附加的实验研究,测出了变速器内两带轮的切向滑动速度。推荐了附加的损耗模型,基于目前其他推荐的理论外,阐述了除论文1和论文2的讨论外的带滑动现象。通过转矩损耗和论文1和论文2中推荐的转矩一力分布的相互作用对比实验范围证实了本文进行的有关分析。本文考虑到其他研究中的新发现,改变目前金属V带的设计。 展开更多
关键词 无级变速箱 机械效率 推带 损耗分析
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金属推型V带无级变速箱损耗机理仿真 部分2:带轮变形损失和总转矩损失的论证
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作者 S.Akehurst N. D. Vaughan +2 位作者 D. A. Parker D. Simner 谷雨(译) 《传动技术》 2006年第1期33-42,共10页
以推型金属带为基体的无级变速箱(CVT)的动力传动效率低于有级变速箱,大家已经认识到采用CVT改进发动机负荷匹配所取得的燃料经济性的好处有被取消的趋势。本组三篇论文详细阐述了发生在作为第一级用来取得效率改进的带传动中损耗机理... 以推型金属带为基体的无级变速箱(CVT)的动力传动效率低于有级变速箱,大家已经认识到采用CVT改进发动机负荷匹配所取得的燃料经济性的好处有被取消的趋势。本组三篇论文详细阐述了发生在作为第一级用来取得效率改进的带传动中损耗机理的研究。本第二篇文章是接上第一篇论文,其中进行了分析由于带轮和带的推块之间相对运动产生的损失。进行附加的实验研究表明在变速器的带轮上产生较大的变形,除第一篇文章讨论之外进一步推荐转矩损失模拟表明转矩损耗较小,但与带有关联的转矩损失仍较大。本研究考虑到其他研究中的新发现并改变金属V带的设计。本组中第三篇论文开发了许多模型,依据于第一篇论文中开发的力分布模型来预测变速器装置中带滑动的损失。 展开更多
关键词 无级变速箱 机械效率 推带 损耗分析
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金属推型V-带无级变速箱损耗机理仿真 部分1:带组摩擦造成的转矩损失
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作者 S Akenurst N D Vaughan +2 位作者 DA Parker D Simner 谷雨 《传动技术》 2005年第4期40-48,共9页
以推型金属带为基体的无级变速箱(CVT)的动力传递效率低于有级变速箱,大家已往认识到采用CVT改进发动机/负荷匹配新取得的燃料经济性的好处有被取消的趋势。本组三篇论文详细阐述了发生在作为第一级用来取得效率改进的带传动中损耗机理... 以推型金属带为基体的无级变速箱(CVT)的动力传递效率低于有级变速箱,大家已往认识到采用CVT改进发动机/负荷匹配新取得的燃料经济性的好处有被取消的趋势。本组三篇论文详细阐述了发生在作为第一级用来取得效率改进的带传动中损耗机理的研究。已经进行试验研究了涉及推型金属V-带CVT空载和低载的转矩损失。本第一篇论文述及发生在金属带CVT由于带推块和带间相对运动造成主要转矩损失的新分析方法。本研究考虑到其他研究中的新发现并改进了金属V-带的设计。本文中采用几种不同的试验方法提供的实验数据推荐了转矩损失的数字模型。本组第二篇论文阐述了由于带轮变形的许多附加转矩损失机理。在第三篇论文中阐述了根据本文的发现提出带滑动损失的分析。 展开更多
关键词 无级变速箱 机械效率 推型带 损耗分析
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A Study on the End-Effector Exchange Mechanism of a Space Robot
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作者 Rui Qu Yuto Takei +3 位作者 Mitsushige Oda Hiroki Nakanishi Armin Wedler Kent Yoshikawa 《Journal of Mechanics Engineering and Automation》 2017年第5期278-284,共7页
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Gastrin and Colon Cancer
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作者 GrahamS.Baldwin 《胃肠病学》 2000年第B08期16-18,共3页
The classical peptide hormone gastrin was identified originally as a stimulant of gastric acid secretion, but is now known to also act as a growth factor for the gastrointestinal mucosa. In an earlier review the exist... The classical peptide hormone gastrin was identified originally as a stimulant of gastric acid secretion, but is now known to also act as a growth factor for the gastrointestinal mucosa. In an earlier review the existing evidence that gastrin and related peptides act as growth factors for the normal colonic mucosa and for colorectal carcinomas was summarised. In this review I will highlight some recent developments in the field. 展开更多
关键词 胃泌激素 结肠癌 肿瘤 消化系统
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Unusual presentation of gastric cancer during treatment of hairy cell leukemia:Exploring the etiological basis of this rare phenomenon
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作者 Shahan Tariq Muhammad Ammar Bin Hamid +3 位作者 Nazia Rahman Lindsey Oleary Kristine Wong Aasim Sehbai 《Cancer Pathogenesis and Therapy》 2023年第2期146-148,共3页
Hairy cell leukemia(HCL)is a rare B-cell lymphoproliferative disorder.Patients typically present with cytopenia and splenomegaly.We describe the case of a 78-year-old patient with refractory HCL who acutely developed ... Hairy cell leukemia(HCL)is a rare B-cell lymphoproliferative disorder.Patients typically present with cytopenia and splenomegaly.We describe the case of a 78-year-old patient with refractory HCL who acutely developed a cystic lesion on the back while receiving moxetumomab pasudotox therapy.Biopsy of the lesion revealed the presence of adenocarcinoma,which prompted a detailed evaluation resulting in a diagnosis of stage IV gastric cancer.Nevertheless,to establish any association between moxetumomab pasudotox therapy and secondary cancer development,a satisfactory number of studies need to be conducted. 展开更多
关键词 Cystic lesion Gastric cancer Hairy cell leukemia
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Effect of dysprosium substitution on magnetic and structural properties of NiFe2O4 nanoparticles 被引量:1
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作者 MAAlmessiere YSlimani +2 位作者 SGüner ABaykal IErcan 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第8期871-878,I0004,共9页
This work investigated the effect of dysprosium(Dy)ions on the structural,microstructural and magnetic properties of nickel nanospinelferrite,NiFe2 O4.The nanoparticles(NPs)of NiDyxFe(2-x)O4(0.0≤x≤0.1)were prepared ... This work investigated the effect of dysprosium(Dy)ions on the structural,microstructural and magnetic properties of nickel nanospinelferrite,NiFe2 O4.The nanoparticles(NPs)of NiDyxFe(2-x)O4(0.0≤x≤0.1)were prepared via the hydrothermal method.The formation of cubic phase of Ni nanoferrite was confirmed through X-ray diffraction,field emission scanning and transmission electron microscopy.Moreover,the magnetic properties of NiDyxFe(2-x)P4(0.01≤x≤0.10)NPs were discussed.The magnetization versus field,M(H)curves exhibit super paramagnetic nature at room temperature and ferrimagnetic nature at low temperature(10 K).A noticeable improvement in the different deduced magnetic parameters is obtained especially for the NiDy(0.07)Fe(1.93)O4(x=0.07)product.The obtained result is mostly derived from the substitution of Fe^3+ions of smaller ionic radii with Dy^3+ions of larger ionic radii that will strengthen the super exchange interactions among nanoparticles.The calculated squareness ratios are found to be much less than 0.5,due to the effect of spin disorder in the surface regions of NiDyxFe(2-x)O4(0.01≤x≤0.10)NPs.The Dy^3+ions substitution increases the magnetic hardness(higher values of remanence Mr,coercivity Hc,and magnetic moment nB)of nickel nanoferrite samples. 展开更多
关键词 NIFE2O4 Dy SUBSTITUTION Structure MAGNETIC properties Super exchange INTERACTIONS RARE earths
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An investigation of roof runoff during rain events at the Royal Military College of Canada and potential discharge to Lake Ontario
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作者 David G. Kelly Ron D. Weir Steven D. White 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第7期1072-1078,共7页
The Royal Military College of Canada, located on the north eastern shore of Lake Ontario, possesses an abundance of copper roofs and lacks surface water treatment prior to discharge into Lake Ontario. Rainwater, roof ... The Royal Military College of Canada, located on the north eastern shore of Lake Ontario, possesses an abundance of copper roofs and lacks surface water treatment prior to discharge into Lake Ontario. Rainwater, roof runoff and soil samples were collected and analyzed for copper and other parameters. Copper was consistently detected in runoff samples with average concentrations of 3200 ± 2100 μg/L. Multivariable linear regression analysis for a dependant copper runoff concentration yielded an adjusted R 2 value of 0.611, based on an independent variable model using minimum temperature, maximum temperature, total precipitation, and wind speed. Lake water samples taken in the vicinity of storm water outfalls draining areas with copper roofs ranged from 2.0 to 40 μg/L copper. Such data exceed the 2.0 μg/L Canadian Water Quality Guidelines for the Protection of Aquatic Life as outlined by the Canadian Council of Ministers of the Environment (CCME). Analysis of raw, filtered and digested forms suggested that the majority of copper present in runoff and lake water samples was in a dissolved form. The majority of soils taken in this study displayed copper concentrations below the 63 μg/g CCME residential/parkland land use limits. These findings suggested that ion exchange processes between runoff water and soil do not occur to a sufficient extent to elevate copper levels in soil. It may therefore be concluded that the eventual fate of copper, which is not discharged via storm water outfalls, is lost to the water table and Lake Ontario through the sub-soil. 展开更多
关键词 copper roof runoff Lake Ontario Canadian water quality guidelines for the protection of aquatic life
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塑造大型综合超市(GMS)的核心竞争力
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作者 刘文烽 《国际商业技术》 2000年第4期42-44,共3页
近年来,GMS已发展成为我国零售业的主力业态之一。本文从商品策略、价格策略、促销策略、商场布局策略等方面,论述了国内GMS如何塑造与强化自身核心竞争力的方向与途径。
关键词 核心竞争力 营销策略 大型综合超市 商品策略
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