期刊文献+
共找到751篇文章
< 1 2 38 >
每页显示 20 50 100
Hard life for sons in the nest?Sex-dependent offspring mortality in Great Tits in urban and forest areas
1
作者 Nora Agh Henriett Anna Dalvári +2 位作者 Krisztián Szabó Ivett Pipoly András Liker 《Avian Research》 SCIE CSCD 2024年第1期91-97,共7页
Sex-biased mortality can occur in birds during development,for example due to sexual differences in energy requirement and/or environmental sensitivity,or the effects of sex hormones or sex differences in the expressi... Sex-biased mortality can occur in birds during development,for example due to sexual differences in energy requirement and/or environmental sensitivity,or the effects of sex hormones or sex differences in the expression of mutations linked to sex chromosomes.The extent of sex-bias in mortality may also be related to environmental conditions that influence offspring development and survival.Urban areas often provide poorer conditions for nestling development resulting in higher offspring mortality compared to natural areas,which may accelerate sex differences in offspring mortality in cities.To test this hypothesis,we examined the sex ratio of dead offspring in Great Tits(Parus major),using 427 samples of unhatched eggs and dead nestlings collected in two urban and two forest sites between 2013 and 2019.The ratio of males in the whole sample of dead offspring(56.9%)was significantly higher than expected by an 1:1 ratio,and the strongest sex biases were detected in urban areas(57.6%males)and in young nestlings(<14 days old,59.0%males).However,the sex ratios of dead offspring did not differ significantly among study sites and between offspring developmental stages.29.3%of unhatched eggs contained a visible embryo,and the proportion of embryo-containing unhatched eggs did not differ significantly between urban and forest study sites.These results suggest male-biased offspring mortality in Great Tits,and highlight the need of large datasets to detect subtle differences between habitats and developmental stages. 展开更多
关键词 Great Tit URBANIZATION Nestling mortality Sex related differences
下载PDF
Second-order divided difference filter for vision-based relative navigation
2
作者 王小刚 崔乃刚 郭继峰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第3期16-20,共5页
A second-order divided difference filter (SDDF) is derived for integrating line of sight measurement from vision sensor with acceleration and angular rate measurements of the follower to estimate the precise relative ... A second-order divided difference filter (SDDF) is derived for integrating line of sight measurement from vision sensor with acceleration and angular rate measurements of the follower to estimate the precise relative position,velocity and attitude of two unmanned aerial vehicles (UAVs).The second-order divided difference filter which makes use of multidimensional interpolation formulations to approximate the nonlinear transformations could achieve more accurate estimation and faster convergence from inaccurate initial conditions than standard extended Kalman filter.The filter formulation is based on relative motion equations.The global attitude parameterization is given by quarternion,while a generalized three-dimensional attitude representation is used to define the local attitude error.Simulation results are shown to compare the performance of the second-order divided difference filter with a standard extended Kalman filter approach. 展开更多
关键词 relative navigation second-order divided difference filter vision sensor unmanned aerial vehicle formation flight
下载PDF
The Differences between the 3rd Edition and the 4th Edition of Oxford Advanced Learner's English-Chinese Dictionary in Compilation 被引量:6
3
作者 Qin Yong 《广州市经济管理干部学院学报》 2003年第2期83-90,共8页
This paper is to analyze the differences between the 3rd edition and 4th edition of Oxford Advanced Learner's English- Chinese Dictionary (hereafter referred to as ALECD3 and ALECD4). By making comparison between ... This paper is to analyze the differences between the 3rd edition and 4th edition of Oxford Advanced Learner's English- Chinese Dictionary (hereafter referred to as ALECD3 and ALECD4). By making comparison between the two dictionaries in the learner's and compiler's perspectives, it high-lights the priority of the 4th edition in content and compilation. Following a brief introduction in Part 1, Part 2 examines the innovations the 3rd edition has made in verb-pattern scheme, compounds, entries, examples, adjectives and appendices from the learner's perspective. Part3 holds a theoretical discussion of prescription and description in the 4th edition. 展开更多
关键词 the 3rd EDITION 第三版 the 4th EDITION 第四版 牛津高级英汉词典 differences 不同点 Oxford ADVANCED Learner'S English--Chinese
下载PDF
On Similarities and Differences between Relative Pronouns in Relative Clauses
4
作者 黄立进 《海外英语》 2011年第14期342-343,共2页
This paper,in two installments,attempts to clarify the finer points in the similarities and differences in the usage of relative pronouns,who,that and which,while they are in relative clauses.They are illustrated and ... This paper,in two installments,attempts to clarify the finer points in the similarities and differences in the usage of relative pronouns,who,that and which,while they are in relative clauses.They are illustrated and justified with examples.The paper,through the comparison of the usages of who,that and which,has shown their similarities and differences from one another.It will enable us to master their usages and help us in studying relative clauses. 展开更多
关键词 relative PRONOUN SIMILARITY difference USAGE relative CLAUSE
下载PDF
Clustering Categorical Data Based on Within-Cluster Relative Mean Difference
5
作者 Jinxia Su Chunjing Su 《Open Journal of Statistics》 2017年第2期173-181,共9页
The clustering on categorical variables has received intensive attention. In dataset with categorical features, some features show the superior performance on clustering procedure. In this paper, we propose a simple m... The clustering on categorical variables has received intensive attention. In dataset with categorical features, some features show the superior performance on clustering procedure. In this paper, we propose a simple method to find such distinctive features by comparing pooled within-cluster mean relative difference and then partition the data upon such features and give subspace of the subgroups. The applications on zoo data and soybean data illustrate the performance of the proposed method. 展开更多
关键词 CLUSTERING CATEGORICAL Variable Distinctive Attribute Pooled Within-Cluster Mean relative difference Hamming Distance
下载PDF
Quantitative prediction of oil saturation of unconsolidated sandstone reservoir based on time-lapse seismic “relative difference method”: Taking Zeta oil field in West Africa as an example
6
作者 LU Hongmei XU Hai +1 位作者 WO Yujin GU Ning 《Petroleum Exploration and Development》 2019年第2期426-434,共9页
In view of the disadvantage that the absolute difference of time-lapse seismic(the difference between monitoring data and base data) is not only related to the change of oil saturation, but also closely related to the... In view of the disadvantage that the absolute difference of time-lapse seismic(the difference between monitoring data and base data) is not only related to the change of oil saturation, but also closely related to the thickness of reservoir, a time-lapse seismic "relative difference method"(the ratio of monitoring data to base data) not affected by the thickness of reservoir but only related to the change of fluid saturation, is proposed through seismic forward modeling after fluid displacement simulation. Given the same change of fluid saturation, the absolute difference of time-lapse seismic conforms to the law of "tuning effect" and seismic reflection of "thin bed", and the remaining oil prediction method based on absolute difference of time-lapse seismic is only applicable to the reservoirs with uniform thickness smaller than the tuning thickness or with thickness greater than the tuning thickness. The relative difference of time-lapse seismic is not affected by reservoir thickness, but only related to the change of fluid saturation. It is applicable to all the deep-sea unconsolidated sandstone reservoirs which can exclude the effect of pressure, temperature, pore type and porosity on seismic. Therefore, the relation between the relative difference of time-lapse seismic and the change of fluid saturation, which is obtained from seismic forward modeling after Gassmann fluid displacement simulation, can be used to quantitatively predict the change of reservoir water saturation and then the distribution of the remaining oil. The application of this method in deep sea Zeta oil field in west Africa shows that it is reasonable and effective. 展开更多
关键词 time-lapse seismic remaining OIL quantitative prediction unconsolidated sandstone reservoir fluid displacement absolute difference relative difference ZETA OIL field WEST AFRICA
下载PDF
人参皂甙Rd对兔脊髓缺血性损伤保护作用的量效关系研究 被引量:2
7
作者 马丽 陈宇 +1 位作者 桑韩飞 熊利泽 《中华神经外科疾病研究杂志》 CAS 2010年第5期422-426,共5页
目的探讨人参皂甙Rd对脊髓缺血性损伤保护作用的剂量效应关系。方法 40只雄性新西兰大白兔,随机分为5组(n=8),采用肾下主动脉阻断法造成脊髓缺血(20min)。对照组:即单纯缺血再灌注组;保护组:即Rd-5组、Rd-10组、Rd-20组和Rd-40组,分别... 目的探讨人参皂甙Rd对脊髓缺血性损伤保护作用的剂量效应关系。方法 40只雄性新西兰大白兔,随机分为5组(n=8),采用肾下主动脉阻断法造成脊髓缺血(20min)。对照组:即单纯缺血再灌注组;保护组:即Rd-5组、Rd-10组、Rd-20组和Rd-40组,分别在缺血前1h从耳缘静脉注射人参皂甙Rd5mg/kg、10mg/kg、20mg/kg、40mg/kg;术后观察神经功能变化并记录再灌注4h、8h、12h、24h和48h神经功能学评分,再灌注48h处死动物后取脊髓(L5~7)标本行病理学观察。结果所有动物均存活,再灌注后48h,Rd-5组神经功能学评分和脊髓前角正常运动神经元计数与对照组相比均无显著性差异(P>0.05);Rd-10组神经功能学评分与对照组相比无显著性差异(P>0.05),但脊髓前角正常运动神经元计数明显高于对照组(P<0.05);Rd-20组、Rd-40组神经功能学评分和脊髓前角正常运动神经元计数均明显高于对照组(P<0.01),但这二组之间无显著性差异(P>0.05)。且每组兔神经功能学评分与其对应脊髓前角正常神经元计数之间有显著相关性(r=0.769.P<0.01)。结论人参皂甙Rd对脊髓缺血性损伤有保护作用,且呈一定的剂量效应关系。 展开更多
关键词 人参皂甙rd 脊髓缺血 剂量效应关系 药物
下载PDF
DRG付费下甲状腺癌大手术患者支付差影响因素分析
8
作者 林振威 吴风琴 +2 位作者 程斌 王锦毓 陈洁 《中国医疗保险》 2024年第5期80-84,共5页
目的:分析疾病诊断相关分组(DRG)付费下甲状腺癌大手术患者支付差的影响因素,为医院合理控制医疗成本提供参考。方法:选取某三甲医院2020—2022年所有甲状腺癌大手术组(KD1)患者作为研究对象,利用描述性统计、单因素方法和二分类Logisti... 目的:分析疾病诊断相关分组(DRG)付费下甲状腺癌大手术患者支付差的影响因素,为医院合理控制医疗成本提供参考。方法:选取某三甲医院2020—2022年所有甲状腺癌大手术组(KD1)患者作为研究对象,利用描述性统计、单因素方法和二分类Logistic回归分析患者支付差的影响因素。结果:住院天数、并发症与合并症、手术部位、是否颈清、是否腔镜、药品占比、耗材占比和手术占比是影响甲状腺癌大手术患者支付差的主要因素。结论:DRG改革下,医院应推广价值医疗的理念,促进临床规范诊疗,并加强病案质量审核,保证DRG正确入组,在此基础上合理调整费用结构,科学管控药耗成本,助力医院高质量发展。 展开更多
关键词 疾病诊断相关分组 支付差 甲状腺癌 住院费用
下载PDF
基于病因病机探讨年龄相关性黄斑变性与骨性关节炎的相关性
9
作者 李晓宇 高云 +5 位作者 梁丽娜 陈强 郭育卿 张帅 杨胜平 崔玉石 《中国中医眼科杂志》 2024年第3期247-252,共6页
年龄相关性黄斑变性(AMD)与骨性关节炎(OA)均为老年常见慢病,是老年退行性改变在人体不同组织器官的病理表现。最新研究发现AMD与OA发病具有相关性,OA患者发生AMD的风险较高,其机制尚未明确,推测可能与补体系统、细胞因子、炎性细胞、... 年龄相关性黄斑变性(AMD)与骨性关节炎(OA)均为老年常见慢病,是老年退行性改变在人体不同组织器官的病理表现。最新研究发现AMD与OA发病具有相关性,OA患者发生AMD的风险较高,其机制尚未明确,推测可能与补体系统、细胞因子、炎性细胞、自噬及Wnt、Notch、丝裂原活化蛋白激酶(MAPK)等多条信号通路有关。从中医病因病机上讲,AMD与OA虽病位与临床表现不同,但二者均为本虚标实之病,与年老肝、脾、肾亏损有关。本文拟从发病危险因素、中医病因病机、病理及分子生物学方面进行探讨AMD与OA异病中的共病规律,从而为AMD及OA的预防和治疗提供新思路。 展开更多
关键词 病因病机 年龄相关性黄斑变性 骨性关节炎 异病同治
下载PDF
多尺度视角下新疆城市化发展地域差异分析
10
作者 玛丽娅木古丽·阿不力米提 杨胜天 布买日也木·买买提 《湖北农业科学》 2024年第3期87-96,共10页
基于熵值法、相关系数以及灰色关联分析,采用SPSS、Matlab及ArcGIS等软件,分析地州和县域尺度下的新疆人口发展水平(PDL)和城市化综合发展水平(CUDL)等级地域差异分布状况及其驱动机制。结果表明,新疆城市化综合发展水平呈增长趋势。北... 基于熵值法、相关系数以及灰色关联分析,采用SPSS、Matlab及ArcGIS等软件,分析地州和县域尺度下的新疆人口发展水平(PDL)和城市化综合发展水平(CUDL)等级地域差异分布状况及其驱动机制。结果表明,新疆城市化综合发展水平呈增长趋势。北疆和东疆呈聚集型增长,南疆呈分散型缓慢增长趋势,整体城市化发展水平呈北高南低趋势,部分偏南边界县域仍处于欠发达状态;2006年前后新疆人口发展水平和城市化综合发展水平等级结构均有明显变化,2010年新疆城市化综合发展水平呈稳增态势;新疆人口发展与城市化综合发展水平之间存在强相关,各子系统与新疆城市化水平得分之间的关联度大小表现为经济城市化>人口城市化>空间城市化>社会城市化。 展开更多
关键词 人口 城市化 熵值法 灰色关联分析 地域差异
下载PDF
基于熵权法和灰色关联度结合成分分析优选人参提取物抗氧化活性最佳极性部位
11
作者 徐志佳 李胜楠 +5 位作者 周文文 肖凤琴 刘晖 杨亦柳 李光哲 严铭铭 《食品工业科技》 CAS 北大核心 2024年第4期211-220,共10页
目的:考察人参不同极性部位抗氧化活性差异,筛选最佳活性部位。方法:本研究以石油醚、氯仿、乙酸乙酯、正丁醇依次萃取人参水提物。通过高效液相色谱(High Performance Liquid Chromatography,HPLC)、紫外分光光度计测定人参不同极性部... 目的:考察人参不同极性部位抗氧化活性差异,筛选最佳活性部位。方法:本研究以石油醚、氯仿、乙酸乙酯、正丁醇依次萃取人参水提物。通过高效液相色谱(High Performance Liquid Chromatography,HPLC)、紫外分光光度计测定人参不同极性部位总酚酸、总皂苷、总多糖、总黄酮、人参皂苷Rg1、人参皂苷Re、人参皂苷Rb1含量;以DPPH自由基、ABTS^(+)自由基、羟基自由基、超氧阴离子自由基及细胞氧化损伤模型测定不同极性部位间体外抗氧化活性;结合熵权法与灰色关联度分析,建立人参不同极性部位的质量评价模型。对人参不同极性部位的12个质量特性指标赋权,最终优选出人参抗氧化最佳极性部位。结果:人参不同极性部位成分含量及抗氧化活性差异明显。其中,正丁醇部位的总酚酸、总黄酮、人参皂苷Rb1含量高于其他部位。正丁醇部位抗氧化活性最强,对DPPH自由基、ABTS^(+)自由基、羟基自由基、超氧阴离子自由基具有一定的清除能力,相应的IC50值分别为0.14、0.57、0.92、0.75 mg/mL。另外,结合质量评价模型得到人参不同极性部位的相对关联度值的范围为0.352~0.618,正丁醇部位测得相对关联度最高(0.618),进一步表明正丁醇部位抗氧化活性最强。结论:综合熵权法和灰色关联度分析的评价结果,初步优选出正丁醇部位为人参抗氧化最理想部位,为人参作为天然抗氧化剂的研究及人参抗氧化食品的开发应用提供理论基础。 展开更多
关键词 人参 不同极性部位 化学成分 抗氧化活性 熵权法 灰色关联分析
下载PDF
基于随机森林回归算法的水泥立式磨磨内压差预测
12
作者 孙胜难 袁铸钢 +1 位作者 刘钊 马洪浩 《洛阳理工学院学报(自然科学版)》 2024年第2期44-50,共7页
水泥立式磨粉磨过程中,准确预测磨内压差对控制和稳定运行至关重要。为了使磨内压差预测值与实际值更接近,提出一种基于随机森林回归(Random Forest Regression, RFR)的预测模型,通过装袋算法(Bagging)和随机特征子空间(Random Subspace... 水泥立式磨粉磨过程中,准确预测磨内压差对控制和稳定运行至关重要。为了使磨内压差预测值与实际值更接近,提出一种基于随机森林回归(Random Forest Regression, RFR)的预测模型,通过装袋算法(Bagging)和随机特征子空间(Random Subspace Method, RSM)强化原决策回归树(Classification And Regression Tree, CART)的泛化能力。利用灰色关联度分析法,验证了关键变量选取的合理性;利用RFR算法建立磨内压差预测模型,得到新的磨内压差值。对比反向传播神经网络(Back Propagation Neural Network, BPNN)预测模型、支持向量机(Support Vector Machines, SVM)预测模型、径向基函数(Radial Basis Function, RBF)神经网络预测模型、长短期记忆(Long Short Term Memory, LSTM)神经网络预测模型的预测结果,RFR模型的预测效果优于其他4种预测模型,在磨内压差预测方面表现良好。 展开更多
关键词 水泥立式磨 磨内压差 随机森林回归 灰色关联度
下载PDF
IgG4相关性疾病(IgG4-RD)发病机制的研究进展 被引量:11
13
作者 纪宗斐 马玲瑛 姜林娣 《复旦学报(医学版)》 CAS CSCD 北大核心 2019年第1期114-118,142,共6页
IgG4相关性疾病(IgG4-related disease,IgG4-RD)是以多发脏器肿大、血清IgG4升高为特点的一类自身免疫性疾病,发病机制仍不明确。病原体感染导致抗原呈递细胞表面模式识别受体激活,通过抗原呈递促进CD4+T细胞激活,分化为Th1、Th2、Treg... IgG4相关性疾病(IgG4-related disease,IgG4-RD)是以多发脏器肿大、血清IgG4升高为特点的一类自身免疫性疾病,发病机制仍不明确。病原体感染导致抗原呈递细胞表面模式识别受体激活,通过抗原呈递促进CD4+T细胞激活,分化为Th1、Th2、Treg和Tfh细胞,产生一系列T细胞因子,进一步促进B细胞活化并转化为浆细胞,产生IgG4。而巨噬细胞和Treg细胞产生的转化生长因子β(transforming growth factorβ,TGF-β)和血小板源性生长因子等进一步促进了纤维化的发生。以上细胞因子和免疫细胞参与IgG4-RD发病,为今后的治疗策略提供了新的思路。 展开更多
关键词 IgG4相关性疾病(IgG4-rd) 发病机制 浆细胞
下载PDF
血清IgG水平和IgG4相关性疾病反应指数在IgG4-RD活动性评估中的应用 被引量:4
14
作者 纪宗斐 马玲瑛 +3 位作者 张丽娟 马莉莉 陈慧勇 姜林娣 《复旦学报(医学版)》 CAS CSCD 北大核心 2020年第5期647-653,共7页
目的验证IgG4相关性疾病(IgG4-related disease,IgG4-RD)反应指数(responder index,RI)在IgG4-RD疾病活动性评估中的诊断效率,并进一步探索新的生物学标志物。方法纳入117例符合2012年日本标准的IgG4-RD患者,由3名专科专家通过医师整体... 目的验证IgG4相关性疾病(IgG4-related disease,IgG4-RD)反应指数(responder index,RI)在IgG4-RD疾病活动性评估中的诊断效率,并进一步探索新的生物学标志物。方法纳入117例符合2012年日本标准的IgG4-RD患者,由3名专科专家通过医师整体评估(physician global assessment,PGA)将患者分为活动组(n=78)和稳定组(n=39)。总结患者的一般情况、临床资料、实验室检查和IgG4-RD RI,分析两组患者一般情况和实验室检查的差异。进一步分析血清标志物及IgG4-RD RI评估IgG4-RD疾病活动性的敏感度、特异度、阳性预测值、阴性预测值和曲线下面积。结果活动组IgG4-RD患者的外周血嗜酸性粒细胞百分比、血小板、血沉、C反应蛋白、IgG、IgG4、球蛋白、白介素6(interleukin-6,IL-6)和可溶性IL-2受体(soluble IL-2 receptor,sIL2R)较稳定组显著升高;血红蛋白、总胆固醇和甘油三酯显著降低。IgG、IgG4、球蛋白、血沉和sIL-2R水平均与IgG4-RD RI呈正相关(P<0.05)。IgG4-RD RI和血清IgG水平用于判断疾病活动性的曲线下面积达到0.940和0.916。以IgG4-RD RI≥6为标准,敏感度和特异度分别可达到92.3%和86.5%;以IgG≥11.6 g/L为标准,敏感度和特异度为89.1%和82.6%。结论在IgG4-RD活动性评估中,IgG4-RD RI评分具有最高的诊断效率,血清IgG水平也可作为疾病活动性的标志物,敏感度和特异度较高,IgG4-RD RI评分和血清IgG水平是临床诊治中可靠、实用的评估方法。 展开更多
关键词 IgG4相关性疾病(IgG4-rd) IGG4 IgG 球蛋白 反应指数(RI)
下载PDF
不同年龄段患者冠状动脉慢血流现象与甲状腺功能的相关性研究
15
作者 吴积团 谢伟 +1 位作者 胡根生 汤文天 《医师在线》 2024年第4期42-45,共4页
目的 探讨不同年龄段患者冠状动脉慢血流现象(CSFP)与甲状腺功能的相关性.方法 选择2021年1月~2023年1月在我院因有胸闷、胸痛等不适症状行冠状动脉造影检查被确诊为CSFP的心内科住院患者72例为研究对象.根据患者年龄分为两组(<60岁... 目的 探讨不同年龄段患者冠状动脉慢血流现象(CSFP)与甲状腺功能的相关性.方法 选择2021年1月~2023年1月在我院因有胸闷、胸痛等不适症状行冠状动脉造影检查被确诊为CSFP的心内科住院患者72例为研究对象.根据患者年龄分为两组(<60岁组和≥60岁组),比较不同年龄组患者甲状腺功能及相关抗体、冠状动脉血流帧数的差异.并使用多因素Logistic回归分析CSFP形成与进展的影响因素.结果 ≥60岁组的游离甲状腺素(FT4)低于<60岁组,差异有统计学意义(P<0.05),但≥60岁组的促甲状腺激素(TSH)明显高于<60岁组,差异有统计学意义(P<0.05);≥60岁组的冠状动脉血流帧数大于<60岁组,差异有统计学意义(P<0.05);<60岁组的甲状腺球蛋白自身抗体(TGAb)及甲状腺过氧化物酶抗体(TPOAb)水平均高于≥60岁组,差异有统计学意义(P<0.05).多因素Logistic回归分析结果显示,<60岁组患者TGAb水平升高是CSFP严重程度的危险因素,≥60岁组患者TSH水平升高是CSFP严重程度的危险因素.结论 FT4、TSH、TGAb、TPOAb对不同年龄段CSFP患者冠状动脉血流缓慢程度影响不同,其中TGAb为影响<60岁组患者冠状动脉血流快慢的危险因素,而TSH为影响≥60岁组患者冠状动脉血流快慢的危险因素. 展开更多
关键词 不同年龄 冠状动脉慢血流 甲状腺功能 相关研究
下载PDF
IgG4-RD中恶性肿瘤发病的相关性研究 被引量:2
16
作者 王月彬 李冰 +2 位作者 李鹏 周志中 张育菘 《实用癌症杂志》 2019年第4期568-571,共4页
目的初步分析IgG4-RD中恶性肿瘤的发病情况,同时分析IgG4对恶性肿瘤的监测意义,为临床上利用IgG4评估恶性肿瘤病情进展及预后提供参考依据。方法选取60例IgG4-RD患者纳入分析,进行Ig G4-RD组与非IgG4-RD组恶性肿瘤发病情况对比、恶性肿... 目的初步分析IgG4-RD中恶性肿瘤的发病情况,同时分析IgG4对恶性肿瘤的监测意义,为临床上利用IgG4评估恶性肿瘤病情进展及预后提供参考依据。方法选取60例IgG4-RD患者纳入分析,进行Ig G4-RD组与非IgG4-RD组恶性肿瘤发病情况对比、恶性肿瘤患者与非恶性肿瘤患者血清Ig G4水平对比以及血清IgG4水平对恶性肿瘤的监测价值分析,同时对肿瘤组及非肿瘤组的T-reg细胞计数进行对比。结果 IgG4-RD组与非IgG4-RD组恶性肿瘤发病情况对比结果显示,除胰腺癌人数构成比在两组间存在统计学差异外(P <0. 05),其他恶性肿瘤人数构成比在两组间均没有统计学差异(P>0. 05);恶性肿瘤患者与非恶性肿瘤患者血清IgG4水平没有统计学差异(P> 0. 05),不同性别恶性肿瘤患者血清Ig G4水平没有统计学差异(P>0. 05),不同年龄及病程恶性肿瘤患者血清IgG4水平有统计学差异(P<0. 05);肿瘤组T-reg细胞计数显著高于非肿瘤组(P <0. 05);血清IgG4对胰腺癌及肝癌的监测价值明显优于其他类型的恶性肿瘤,且二者的ROC曲线下面积达到优质诊断指标的临界标准(曲线下面积大于0. 6)。结论 T-reg细胞计数的升高是IgG4-RD中恶性肿瘤发病的重要指征之一,血清IgG4对胰腺癌和肝癌的监测价值也明显优于其他类型的恶性肿瘤,说明血清Ig G4水平的升高与胰腺癌的相关性较其他恶性肿瘤更高;但本研究其他结果则表明血清IgG4水平对恶性肿瘤的发生与否仅有一定的提示意义,并不具有作为诊断依据的研究价值。 展开更多
关键词 IgG4相关性疾病(IgG4-rd) T-reg细胞 恶性肿瘤 相关性 ROC曲线
下载PDF
人参皂苷Rd通过下调Nrf2表达调控H460细胞的增殖和凋亡 被引量:3
17
作者 钱松 柴尹泽 +4 位作者 余潇苓 苗青 赵燕娜 高瑞兰 尹利明 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2020年第5期566-572,共7页
核转录因子红细胞系-2p45相关因子-2(nuclear factor erythroid-2p45-related factor 2,Nrf2)是细胞应对外界应激的主要调控因子,通过调控一系列细胞保护酶,维持细胞稳态。然而,在许多肿瘤细胞中Nrf2过度激活,导致肿瘤细胞获得增殖优势... 核转录因子红细胞系-2p45相关因子-2(nuclear factor erythroid-2p45-related factor 2,Nrf2)是细胞应对外界应激的主要调控因子,通过调控一系列细胞保护酶,维持细胞稳态。然而,在许多肿瘤细胞中Nrf2过度激活,导致肿瘤细胞获得增殖优势并产生化疗耐药,因此,靶向抑制Nrf2是肿瘤增敏治疗的一种新思路。人参皂苷Rd是人参皂苷中的重要活性成分,具有显著的抗肿瘤作用。本研究以不同浓度的人参皂苷Rd处理人非小细胞肺癌(non-small cell lung cancer,NSCLC)H460细胞,利用CCK-8法检测细胞活力;倒置显微镜观察H460细胞的形态变化;流式细胞术检测细胞周期及凋亡率;RT-qPCR和Western印迹检测的Nrf2及其下游调控基因的表达情况;此外通过转染Nrf2-siRNA下调H460细胞中Nrf2的表达,观察其对人参皂苷Rd增敏的影响。结果显示,与对照组相比,人参皂苷Rd能够抑制H460细胞增殖活力,诱导细胞G0/G1期阻滞,促进细胞凋亡,具有剂量依赖性(P<0.05);此外,人参皂苷Rd能够下调Nrf2,醌氧化还原酶1[NAD(P)H:quinoneoxidoreductase,NQO1],谷氨酰半胱氨酸连接酶催化亚基(glutamate--cysteine ligase catalytic subunit,GCLC)和调节亚基(glutamate--cysteine ligase regulatory subunit,GCLM)的mRNA和蛋白质水平,同时增强H460细胞对化疗药的敏感性(P<0.05),而转染Nrf2-siRNA后,人参皂苷Rd的增敏作用减弱。表明人参皂苷Rd可以抑制非小细胞肺癌H460细胞活性并增敏化疗,其机制可能是通过抑制Nrf2信号通路来实现。 展开更多
关键词 人参皂苷rd 细胞毒性 非小细胞肺癌 核转录因子红细胞系-2p45相关因子-2 增敏
下载PDF
Limb symmetry index in competitive alpine ski racers:Reference values and injury risk identification according to age-related performance levels 被引量:6
18
作者 Lisa Steidl-Müller Carolin Hildebrandt +2 位作者 Erich Müiller Christian Fink Christian Raschner 《Journal of Sport and Health Science》 SCIE 2018年第4期405-415,共11页
Purpose: The aims of this study were to assess differences of limb symmetry index(LSI) in strength-and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related perform... Purpose: The aims of this study were to assess differences of limb symmetry index(LSI) in strength-and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers.Methods: The study(Study 1) included 285 high-level competitive ski racers(125 females, 160 males) of 3 age-related performance levels and based on the school system: 95 youth(10à14 years, secondary modern school), 107 adolescent(15à19 years, grammar school), and 83 elite athletes(20à34 years). To investigate the second aim(Study 2), 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests(strength related: one-leg counter movement jump(OL-CMJ) and one-leg isometric/isokinetic press strength test(OL-ILS); coordination related: one-leg stability test(OL-ST) and one-leg speedy jump test(OL-SJ)). The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted.Results: There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests: the OL-CMJ(x2(2, 285) = 9.09; p = 0.01) and the OL-ILS(x2(2, 285) = 14.79; p < 0.01). The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers(Wald = 7.08; p < 0.01). No significant risk factors were found for overuse injuries.Conclusion: Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of <10%for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks(strength vs. coordination related) rather than on generalizations,and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers. 展开更多
关键词 年龄相关 风险因素 滑雪 损害 竞争 大规模集成电路 性能 索引
下载PDF
Some new generalized difference sequence spaces defined by a sequence of moduli
19
作者 Vakeel A Khan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第1期104-108,共5页
The idea of difference sequence sets X(△) = {x = (xk) : △x ∈ X} with X = l∞, c and co was introduced by Kizmaz [12]. In this paper, using a sequence of moduli we define some generalized difference sequence sp... The idea of difference sequence sets X(△) = {x = (xk) : △x ∈ X} with X = l∞, c and co was introduced by Kizmaz [12]. In this paper, using a sequence of moduli we define some generalized difference sequence spaces and give some inclusion relations. 展开更多
关键词 difference sequence space sequence of moduli inclusion relation.
下载PDF
The Exploration to the Historical Origin of Differences between Urban and Rural Areas in China
20
作者 ZHU Hong-liang ZHANG Rui-qing 《Asian Agricultural Research》 2011年第1期118-121,126,共5页
In order to understand the historical origins of encircling the cities from the rural areas implemented by the Communist Party of China and the current dual structures of urban and rural development, urban-rural diffe... In order to understand the historical origins of encircling the cities from the rural areas implemented by the Communist Party of China and the current dual structures of urban and rural development, urban-rural differences are analyzed from the four aspects of production mode, management mode, culture and social division of labor. Industrial development in modern times has promoted the modernization of urban production in China. But the rural areas still maintain their traditional self-sufficient natural economy. After the Opium War, the process of modernization of city politics is promoted by more economic elements of capitalism and the formation of Chinese bourgeoisie. During the management of urban modernization, rural areas still adopt the traditional self-management mode. In the aspect of culture, city is the center of development, having large population, developed traffic, and prosperous culture. But the village is lack of information and its culture is relatively backward. In modern times, affected by the foreign capitalist, urban area has become the center of modern productivity. After separating from agriculture, handicraft industry has transferred into urban areas and the social division of labor in both urban and rural areas has shown great changes. Thus, a new pattern of "Urban Industry, Rural Agriculture" has formed. 展开更多
关键词 Urban and rural areas RELATION difference HISTORY China
下载PDF
上一页 1 2 38 下一页 到第
使用帮助 返回顶部