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考虑多退化失效和突发失效之间竞争失效的可靠性评估方法

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中国机械工程 2017年第1期28卷 7-12页

作者：刘晓娟王华伟徐璇南京航空航天大学民航学院南京211106

提出了考虑多退化失效和突发失效之间竞争失效的可靠性评估方法。由协方差分析了多元退化信息之间的相关性及相关程度,建立多退化失效模式的可靠性评估模型,且选用了多元正态分布来建立模型。构建基于退化量突发失效的条件概率,分析退... 详细信息

提出了考虑多退化失效和突发失效之间竞争失效的可靠性评估方法。由协方差分析了多元退化信息之间的相关性及相关程度,建立多退化失效模式的可靠性评估模型,且选用了多元正态分布来建立模型。构建基于退化量突发失效的条件概率,分析退化失效对突发失效的影响,通过多个退化模式的退化失效与突发失效的联合概率分布函数建立竞争失效的可靠性评估模型。最后以航空发动机的失效数据为例,验证了模型的有效性。

关键词：多退化失效模式突发失效系统可靠性评估竞争失效

Establishment of a real-time PCR for quantifying transforming growth factor beta1 in blood of hepatocellular carcinoma patients

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Journal of Medical Colleges of PLA(China) 2008年第4期23卷 228-236页

作者： Qi Peng Gao Chunfang Fang Meng Ji Qiang Zhao Yunpeng liu Yan Sun xiaojuan Department of Laboratoty Medicine Eastern Hepatobiliary Hospital Second Military Medical University Shanghai 200438 China

Background: The carcinogenesis of hepatocellular carcinoma (HCC) is a multi-factorial, multistep and complex process. Its prognosis is poor and early detection is of the utmost importance. Transforming growth factor β1 (TGF-β1) message RNA (mRNA) has been reported to be elevated in HCC patients using Northern blotting. However, little work has been done about the detection of TGF-β1 mRNA levels in peripheral blood of patients with HCC using the real-time polymerase chain reactions (PCR) method. Objective: To assess the prognostic value of quantitative levels of TGF-β1 mRNA in peripheral blood of patients with HCC, and to investigate the relationship between the expression of TGF-β1 mRNA in peripheral blood and many diagnostic and pathological factors. Methods: We developed an optimized Taqman real-time PCR to quantify TGF-β1 mRNA in peripheral blood of 53 patients with HCC and 44 healthy volunteers. In addition, blood was collected from patients with HCC for measuring levels of total bilirubin (TBil), prealbumin, albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltranspeptidase (GGT), alpha-L-fucosidase (AFU), alpha fetoprotein (AFP), carcino-embryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), viral load and platelet counts. Statistical analysis was performed using the SPSS software system (SPSS 10.0). Results: In real-time PCR, fluorescence was detectable in all blood specimens from patients with HCC and healthy volunteers. The levels of TGF-β1 mRNA expression in patients with HCC were significantly higher compared to that in healthy volunteers (P<0.000 1), suggesting an association of the activated TGF-β1 gene transcription with hepato- carcinogenesis. Patients with HCC were divided into 2 groups according to their TGF-β1 mRNA above (group A, n=28)or below (group B, n=25) the mean level. Statistical results demonstrated that TGF-β1 mRNA expression level was correlated with patients age, serum levels of CEA, CA19-9 and

关键词： Hepatocellular carcinoma: Early diagnosis Molecular marker Transforming growth factor beta l Messenger RNA Quantitative PCR.

Suppression of Jasmonic Acid-Mediated Defense by Viral-Inducible MicroRNA319 Facilitates Virus Infection in Rice

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Molecular Plant 2016年第9期9卷 1302-1314页

作者： Chao Zhang Zuomei Ding Kangcheng Wu Liang Yang Yang Li Zhen Yang Shan Shi xiaojuan liu Shanshan Zhao Zhirui Yang Yu Wang Luping Zheng Juan Wei Zhenguo Du Aihong Zhang Hongqin Miao Yi Li Zujian Wu Jianguo Wu Fujian Province Key Laboratory of Plant Virology Institute of Plant Virology Fujian Agriculture and Forestry University Fuzhou Fujian 350002 China The State Key Laboratory of Protein and Plant Gene Research College of Life Sciences Peking University Beijing 100871 China / Plant Protection Institute Hebei Academy of Agriculture and Forestry Sciences Baoding 071000 China These authors contributed equally to this article.

MicroRNAs （miRNAs） are pivotal modulators of plant development and host-virus interactions. However, the roles and action modes of specific miRNAs involved in viral infection and host susceptibility remain largely unclear. In this study, we show that Rice ragged stunt virus （RRSV） infection caused increased accumulation of miR319 but decreased expression of miR319-regulated TCP （TEOSINTE BRANCHED/ CYCLOIDEA/PCF） genes, especially TCP21, in rice plants. Transgenic rice plants overexpressing miP,319 or downregulating TCP21 exhibited disease-like phenotypes and showed significantly higher susceptibility to RRSV in comparison with the wild-type plants. In contrast, only mild disease symptoms were observed in RRSV-infected lines overexpressing TCP21 and especially in the transgenic plants overexpressing miR319- resistant TCP21. Both RRSV infection and overexpression of miR319 caused the decreased endogenous jasmonic acid （JA） levels along with downregulated expression of JA biosynthesis and signaling-related genes in rice. However, treatment of rice plants with methyl jasmonate alleviated disease symptoms caused by RRSV and reduced virus accumulation. Taken together, our results suggest that the induction of miR319 by RRSV infection in rice suppresses JA-mediated defense to facilitate virus infection and symp- tom development.

关键词： miR319 rice ragged stunt virus RRSV TCP21 viral infection jasmonic acid

Global multifaceted biodiversity patterns,centers,and conservation needs in angiosperms

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Science China(Life Sciences) 2024年第4期67卷 817-828页

作者： Ao Luo Yaoqi Li Nawal Shrestha Xiaoting Xu Xiangyan Su Yichao Li Tong Lyu Kilara Waris Zhiyao Tang xiaojuan liu Luxiang Lin Yongsheng Chen Kuiling Zu Wenqi Song Shijia Peng Niklaus E.Zimmermann Loïc Pellissier Zhiheng Wang Institute of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of Education College of Urban and Environmental SciencesPeking UniversityBeijing 100871China Department of Health and Environmental Sciences Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China State Key Laboratory of Grassland Agro-Ecosystems College of EcologyLanzhou UniversityLanzhou 730000China Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education College of Life SciencesSichuan UniversityChengdu 610065China Land Consolidation and Rehabilitation Center Ministry of Natural ResourcesBeijing 100035China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesKunming 650201China Swiss Federal Research Institute WSL Birmensdorf 8903Switzerland Department of Environmental Systems Science ETH ZürichZürich 8092Switzerland

The Convention on Biological Diversity seeks to conserve at least 30%of global land and water areas by 2030,which is a challenge but also an opportunity to better preserve biodiversity,including flowering plants(angiosperms).Herein,we compiled a large database on distributions of over 300,000 angiosperm species and the key functional traits of 67,024 *** this database,we constructed biodiversity-environment models to predict global patterns of taxonomic,phylogenetic,and functional diversity in terrestrial angiosperms and provide a comprehensive mapping of the three diversity *** further evaluated the current protection status of the biodiversity centers of these diversity *** results showed that geographical patterns of the three facets of plant diversity exhibited substantial spatial mismatches and nonoverlapping conservation *** centers of functional diversity,particularly of herbaceous species,were primarily distributed in temperate regions and under weaker protection compared with other biodiversity centers of taxonomic and phylogenetic *** global assessment of multifaceted biodiversity patterns and centers highlights the insufficiency and unbalanced conservation among the three diversity facets and the two growth forms(woody ***),thus providing directions for guiding the future conservation of global plant diversity.

关键词： angiosperms species richness phylogenetic diversity functional diversity plant traits woody species herbaceous species

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添加剂作用下阿司匹林结晶模拟和实验研究

化工学报 2021年第9期72卷 4796-4807页

作者：李闯张扬刘小娟王学重华南理工大学化学与化工学院广东广州510640 北京石油化工学院新材料与化工学院北京市恩泽生物质精细化工重点实验室制药和结晶系统工程团队北京102617

晶体形貌作为晶体产品的重要质量指标,不仅会影响产品流动性、稳定性、溶出速率和生物可利用度等产品的质量指标,还会对过滤、干燥、压片等下游操作造成影响。通过分子模拟的方法指导阿司匹林冷却-反溶剂结晶过程的添加剂筛选,以添加剂... 详细信息

晶体形貌作为晶体产品的重要质量指标,不仅会影响产品流动性、稳定性、溶出速率和生物可利用度等产品的质量指标,还会对过滤、干燥、压片等下游操作造成影响。通过分子模拟的方法指导阿司匹林冷却-反溶剂结晶过程的添加剂筛选,以添加剂作为晶体形貌的改性剂,降低阿司匹林晶体的长径比优化晶体形貌。通过单因素实验考查了添加剂浓度、晶种加入量、降温速率、搅拌速率和加水速率对阿司匹林晶体产品形貌、流动性和粒度分布等的影响,确定了较优的工艺条件。实验结果表明加入聚乙烯吡咯烷酮(PVP)作为添加剂可以降低阿司匹林晶体长径比,获得形貌为短棱柱状的晶体产品,能够显著改变晶体形貌优化产品的流动性。

关键词：结晶阿司匹林分子模拟添加剂聚乙烯吡咯烷酮晶体形貌优化

雨生红球藻多糖的分离纯化和免疫活性组分鉴定

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食品科学 2019年第2期40卷 52-58页

作者：刘涵张苗刘晓娟曹庸华南农业大学食品学院广东省功能食品活性物重点实验室广东省天然活性物工程技术研究中心广东广州510642

以虾青素提取后的雨生红球藻渣为原料,在体外免疫细胞模型活性跟踪下,对超声辅助提取的雨生红球藻粗多糖(Haematococcus pluvialis polysaccharide,HPP)采用DEAE-52纤维素阴离子交换柱层析和Sephacryl S400葡聚糖凝胶柱层析进行分离纯化... 详细信息

以虾青素提取后的雨生红球藻渣为原料,在体外免疫细胞模型活性跟踪下,对超声辅助提取的雨生红球藻粗多糖(Haematococcus pluvialis polysaccharide,HPP)采用DEAE-52纤维素阴离子交换柱层析和Sephacryl S400葡聚糖凝胶柱层析进行分离纯化,使用高效凝胶渗透色谱法测定各组分多糖分子质量。结果表明:HPP经DEAE-52柱层析分离得到HPP-c1、HPP-c2、HPP-c3、HPP-c4和HPP-c5五个多糖组分,其中HPP-c3免疫活性较好且含量最高;HPP-c3经Sephacryl S400柱层析分离得到HPP-c3-s1、HPP-c3-s2和HPP-c3-s3,其中HPP-c3-s1在0～250μg/mL质量浓度范围内极显著刺激小鼠脾细胞的增殖(P<0.01),并呈现剂量效应,最高刺激指数达1.34,高于HPP-c3-s2和HPP-c3-s3。经纯度鉴定,HPP-c3-s1为均一多糖,分子质量为23 413 kDa。研究结果可为雨生红球藻的高值化综合利用提供有利指导。

关键词：雨生红球藻多糖分离纯化免疫活性

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锈蚀钢筋混凝土框架地震损伤性能研究

中南大学学报（自然科学版） 2019年第6期50卷 1437-1446页

作者：刘小娟蒋欢军郭子雄华侨大学土木工程学院福建厦门361021 华侨大学福建省结构工程与防灾重点实验室福建厦门361021 同济大学土木工程防灾国家重点实验室上海200092

为研究地震作用下锈蚀钢筋混凝土框架的损伤发展特点及抗震性能退化规律,进行锈蚀钢筋混凝土框架的拟静力加载试验。共设计制作5榀单层单跨钢筋混凝土框架,采用全浸泡通电加速锈蚀法对其中4榀框架的纵筋进行加速锈蚀。研究钢筋锈蚀对钢... 详细信息

为研究地震作用下锈蚀钢筋混凝土框架的损伤发展特点及抗震性能退化规律,进行锈蚀钢筋混凝土框架的拟静力加载试验。共设计制作5榀单层单跨钢筋混凝土框架,采用全浸泡通电加速锈蚀法对其中4榀框架的纵筋进行加速锈蚀。研究钢筋锈蚀对钢筋混凝土框架地震破坏模式、残余变形、裂缝发展、强度退化、刚度退化以及耗能能力等的影响。研究结果表明:纵筋锈蚀对钢筋混凝土框架的地震损伤发展影响显著。与未锈蚀框架相比,锈蚀框架在拟静力荷载作用下的损伤更集中,发展更快;钢筋混凝土框架的承载能力、变形能力以及耗能能力随着锈蚀率的增大而降低。且与承载能力相比,钢筋混凝土框架的变形能力及耗能能力受锈蚀率影响更显著;随着钢筋锈蚀率的增大,锈蚀框架在较小的位移幅值即出现明显的强度退化。

关键词：锈蚀钢筋混凝土框架锈蚀损伤抗震性能地震损伤发展

退休对中国老年人口身体健康和心理健康的影响

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人口研究 2017年第5期41卷 74-88页

作者：刘生龙郎晓娟清华大学国情研究院中南财经政法大学工商管理学院

文章基于2010、2012和2014年中国家庭动态跟踪调查(CFPS)数据,利用中国退休政策在男女退休年龄上的规定,使用断点回归设计,探讨退休对身体健康和心理健康的影响,并检验退休影响健康的机制。研究发现,退休对男性的健康影响不显著,而对女... 详细信息

文章基于2010、2012和2014年中国家庭动态跟踪调查(CFPS)数据,利用中国退休政策在男女退休年龄上的规定,使用断点回归设计,探讨退休对身体健康和心理健康的影响,并检验退休影响健康的机制。研究发现,退休对男性的健康影响不显著,而对女性的自评健康和心理健康产生显著正向的影响,主要原因是退休后女性增加了锻炼的频率;虽然男性的锻炼频率在退休后也有所增加,但退休后男性超重的概率也随之增加,这很可能在一定程度上抵消了锻炼的健康效应。文章具有明显的政策含义,当前中国政府正在考虑实施渐进式延迟退休政策以应对人口老龄化背景下劳动力不足的问题,研究表明延迟退休不能够以牺牲老年人口的健康为代价,中国需要切实推进"健康老龄化"的战略。

关键词：退休身体健康心理健康断点回归设计

多营养级生物多样性与陆地生态系统多功能性:研究现状与展望

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中国科学：生命科学 2024年第4期54卷 739-750页

作者：李逸刘晓娟中国科学院植物研究所植被与环境变化国家重点实验室北京100093

生物多样性是人类赖以生存的基础,但由于受到人类活动以及全球变化的影响正加速丧失,这对全球生态系统造成巨大威胁.近年来,生物多样性与生态系统功能关系(biodiversity and ecosystem functioning,BEF)已经成为生物多样性保护和气候变... 详细信息

生物多样性是人类赖以生存的基础,但由于受到人类活动以及全球变化的影响正加速丧失,这对全球生态系统造成巨大威胁.近年来,生物多样性与生态系统功能关系(biodiversity and ecosystem functioning,BEF)已经成为生物多样性保护和气候变化领域关注的热点问题之一,并由早期的单一营养级多样性与单个生态系统功能关系,发展到近年来的多营养级生物多样性与生态系统多功能性关系.本文介绍了多营养级生物多样性以及生态系统多功能性的基础概念,回顾了多营养级生物多样性与陆地生态系统多功能性研究的发展历程,并系统归纳了该领域近十年的重要研究进展.在此基础上,提出未来需要重点关注的3个方面:(ⅰ)基于控制实验的驱动机制研究;(ⅱ)地下多营养级生物多样性与生态系统多功能性的关系;(ⅲ)多营养级生物多样性与生态系统多功能性关系随时间尺度的变化.最后,本文呼吁不同研究方向的学者未来应加强合作并强调了开展整合性工作的必要性.

关键词：全球变化土地利用生物多样性丧失营养级互作