首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13498篇
  免费   1845篇
  国内免费   286篇
耳鼻咽喉   50篇
儿科学   140篇
妇产科学   110篇
基础医学   1186篇
口腔科学   176篇
临床医学   1086篇
内科学   1128篇
皮肤病学   70篇
神经病学   632篇
特种医学   461篇
外科学   857篇
综合类   2385篇
现状与发展   1篇
一般理论   8篇
预防医学   3895篇
眼科学   105篇
药学   1605篇
  8篇
中国医学   1222篇
肿瘤学   504篇
  2024年   115篇
  2023年   498篇
  2022年   821篇
  2021年   1050篇
  2020年   934篇
  2019年   732篇
  2018年   628篇
  2017年   711篇
  2016年   642篇
  2015年   620篇
  2014年   943篇
  2013年   1102篇
  2012年   654篇
  2011年   740篇
  2010年   549篇
  2009年   511篇
  2008年   552篇
  2007年   551篇
  2006年   507篇
  2005年   422篇
  2004年   375篇
  2003年   310篇
  2002年   258篇
  2001年   175篇
  2000年   133篇
  1999年   103篇
  1998年   108篇
  1997年   99篇
  1996年   74篇
  1995年   55篇
  1994年   75篇
  1993年   63篇
  1992年   56篇
  1991年   52篇
  1990年   44篇
  1989年   52篇
  1988年   37篇
  1987年   47篇
  1986年   34篇
  1985年   29篇
  1984年   31篇
  1983年   18篇
  1982年   25篇
  1981年   11篇
  1980年   23篇
  1979年   8篇
  1978年   8篇
  1977年   8篇
  1976年   11篇
  1974年   7篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.

Objective

The aim of the study was to estimate the effect of the state-based reinsurance programs through the section 1332 State Innovation Waivers on health insurance marketplace premiums and insurer participation.

Data Source

2015 to 2022 Robert Wood Johnson Foundation Health Insurance Exchange Compare Datasets.

Study Design

An event study difference-in-differences (DD) model separately for each year of implementation and a synthetic control method (SCM) are used to estimate year-by-year effects following program implementation.

Data Collection/Extraction Methods

Not applicable.

Principal Findings

Reinsurance programs were associated with a decline in premiums in the first year of implementation by 10%–13%, 5%–19%, and 11%–17% for bronze, silver, and gold plans (p < 0.05). There is a trend of sustained declines especially for states that implemented their programs in 2019 and 2020. The SCM analyses suggest some effect heterogeneity across states but also premium declines across most states. There is no evidence that reinsurance programs affected insurer participation.

Conclusion

State-based reinsurance programs have the potential to improve the affordability of health insurance coverage. However, reinsurance programs do not appear to have had an effect on insurer participation, highlighting the need for policy makers to consider complementary strategies to encourage insurer participation.  相似文献   
2.
In clinical and epidemiological studies, there is a growing interest in studying the heterogeneity among patients based on longitudinal characteristics to identify subtypes of the study population. Compared to clustering a single longitudinal marker, simultaneously clustering multiple longitudinal markers allow additional information to be incorporated into the clustering process, which reveals co-existing longitudinal patterns and generates deeper biological insight. In the current study, we propose a Bayesian consensus clustering (BCC) model for multivariate longitudinal data. Instead of arriving at a single overall clustering, the proposed model allows each marker to follow marker-specific local clustering and these local clusterings are aggregated to find a global (consensus) clustering. To estimate the posterior distribution of model parameters, a Gibbs sampling algorithm is proposed. We apply our proposed model to the primary biliary cirrhosis study to identify patient subtypes that may be associated with their prognosis. We also perform simulation studies to compare the clustering performance between the proposed model and existing models under several scenarios. The results demonstrate that the proposed BCC model serves as a useful tool for clustering multivariate longitudinal data.  相似文献   
3.
目的 基于文本挖掘技术和生物医学数据库对新型冠状病毒肺炎(COVID-19)相关文献进行数据挖掘分析,探究COVID-19及其主要症状发热、咳嗽、呼吸障碍相关基因靶点,筛选潜在有效的化学药和中药。方法 使用GenCLiP 3网站获取COVID-19和其主要症状咳嗽、发热、呼吸障碍共4个关键词的共有靶点,在METASCAPE数据库中对其进行基因本体(GO)和通路富集分析,再利用String数据库和Cytoscape软件构建共有靶点的蛋白质相互作用网络,筛选获得核心基因,运用DGIdb数据库、SymMap数据库针对核心基因进行中西医治疗药物预测。结果 获得COVID-19及其主要症状共有基因靶点28个,其中有IL2、IL1B、CCL2等核心基因16个,使用DGIdb数据库筛选获得与16个关键靶点相互作用的化学药包括沙利度胺、来氟米特、环孢素等28种,中药包括虎杖、黄芪、芦荟等70味。结论 COVID-19及其主要症状的病理机制可能和CD4、KNG1、VEGFA等28个共有基因相关,可能通过介导TNF、IL-17等信号通路参与COVID-19病理过程。潜在有效药物可能通过作用相关靶点通路起到治疗COVID-19的作用。  相似文献   
4.
目的 基于临床信息系统分析总结真实世界的数据,采用数据挖掘的方法探讨中医药治疗糖尿病肾病的用药规律。方法 收集2018年1月-2020年12月上海中医药大学附属曙光医院宝山分院健康信息系统确诊的糖尿病肾病的门诊或住院患者的诊疗信息,建立Excel数据库,采用Excel 2010软件统计高频药物的四气、五味、归经及功效;使用SPSS Modeler 18.0软件中的Apriori算法分析关联规则,采用web节点建构药对关联网状图;运用SPSS 25统计软件进行因子分析。结果 本研究最终纳入477例接受中药饮片治疗的DKD患者,在1203条方剂信息中,涉及中药462种;使用频数排名前5位的中药分别是黄芪、黄精、石斛、山茱萸、麦冬;使用频数前5类的中药类别分别是补气药、补阴药、清热燥湿药、活血调经药、息风止痉药;在30味高频药物中,苦、甘、辛药味最为常见;药性寒、温数量接近;归脾经、肝经、肺经、肾经居多;关联规则提示,药物组合中置信度最高的组合为地龙-当归-僵蚕,因子分析共得到5个有效因子,累积贡献率为47.33%。结论 中医药治疗DKD在补益气血阴阳的同时,兼顾对瘀血、湿邪和痰饮的治疗,结合证型,可考虑使用黄芪、黄精、石斛、山茱萸、麦冬、金蝉花等药物的使用,清热燥湿药物如黄连、黄芩、黄柏可适当加入,为使邪有去处,大黄、车前子或可增添疗效。  相似文献   
5.
6.
《Vaccine》2016,34(51):6626-6633
BackgroundSafety signal detection in spontaneous reporting system databases and electronic healthcare records is key to detection of previously unknown adverse events following immunization. Various statistical methods for signal detection in these different datasources have been developed, however none are geared to the pediatric population and none specifically to vaccines. A reference set comprising pediatric vaccine-adverse event pairs is required for reliable performance testing of statistical methods within and across data sources.MethodsThe study was conducted within the context of the Global Research in Paediatrics (GRiP) project, as part of the seventh framework programme (FP7) of the European Commission. Criteria for the selection of vaccines considered in the reference set were routine and global use in the pediatric population. Adverse events were primarily selected based on importance. Outcome based systematic literature searches were performed for all identified vaccine-adverse event pairs and complemented by expert committee reports, evidence based decision support systems (e.g. Micromedex), and summaries of product characteristics. Classification into positive (PC) and negative control (NC) pairs was performed by two independent reviewers according to a pre-defined algorithm and discussed for consensus in case of disagreement.ResultsWe selected 13 vaccines and 14 adverse events to be included in the reference set. From a total of 182 vaccine-adverse event pairs, we classified 18 as PC, 113 as NC and 51 as unclassifiable. Most classifications (91) were based on literature review, 45 were based on expert committee reports, and for 46 vaccine-adverse event pairs, an underlying pathomechanism was not plausible classifying the association as NC.ConclusionA reference set of vaccine-adverse event pairs was developed. We propose its use for comparing signal detection methods and systems in the pediatric population.  相似文献   
7.
BackgroundPreschool age is a critical stage of postural balance development. Posturography normative data during this age are crucial for surveillance of postural balance and for the timely diagnosis of any dysfunction. The aim of this study was to provide normative data, specific to Tunisian preschoolers, according to age and gender, and to examine gender- and age-related differences in postural balance.Research questionAre there postural balance gender- and age-related differences in Tunisian preschoolers?MethodsThe study included 410 (205 boys and 205 girls) preschool children aged between 4- and 5-year-old selected within a large geographic area of Tunisia. Postural balance was assessed using a stabilometric platform under 4 sensory conditions. The mean center of pressure velocity (CoP-V) parameter was selected for analysis. Differences between gender and age groups were analysed using the Mann–Whitney U. Normative data were expressed in percentiles.ResultsSignificant gender effect was found in conditions where sensory inputs are most challenged with a significantly smaller mean CoP-V in girls compared to boys (p < 0.05). Moreover, 5-year-old children had significantly better postural balance than 4-year-old ones in almost all conditions (p < 0.05).SignificanceThe normative data established for Tunisian preschoolers provide useful comparative data for pediatricians, teachers and coaches for the early evaluation and monitoring of postural balance during this age. Gender and age-related differences should be considered in this population.  相似文献   
8.
PurposeBibliometric studies have been established methods of analysing publications on a particular topic. These studies have been done on various orthopaedic topics and are increasing. The advantages of these studies have been highlighted in previous publications. Although some studies have been done on Indian publications from other specialties, those analysing Indian Orthopaedic Publications are lacking.MethodsWe performed a search in Scopus to look for all publications related to orthopaedics from India. Our search strategy in Scopus included ((TITLE-ABS-KEY(Orthopaedics OR Orthopaedics) AND AFFIL(India)) AND PUBYEAR > 2009 AND PUBYEAR < 2020) which resulted in 3270 articles on 02/11/2021. We analyzed the most publishing universities, city, state, specialty, authors, and anatomic location of these publications. We also mined the data to draw word clouds based on data obtained from the titles of articles, keywords and the affiliations of each of the articles published.ResultsTamil Nadu and New Delhi and their institutes appear to be the epicenter of publication activities in Orthopaedics in India. There has been a healthy trend of growth of articles in the orthopaedic specialty. Since there is a significant overlap of technology and engineering, it is not surprising to see engineering and technology institutes among the top 10 published institutes and even journals for the publications on orthopaedics.ConclusionThere has been a steady increase in the number of publications in the last decade. New Delhi and its Universities and Institutes appear to contribute the majority of citations and publications related to orthopaedics. Journal of Clinical Orthopaedics and Trauma was the most publishing journal for Indian authors on Orthopaedic related articles.  相似文献   
9.
刘晓  张志常 《现代肿瘤医学》2019,(23):4169-4175
目的:分析2010年至2018年甲状腺结节相关SCI论文,并建模进行定性与定量分析。方法:利用文献计量学中的引文分析、共被引分析、数据可视化、聚类分析等方法,使用CiteSpace分析工具,分析来源于Web of ScienceTM核心合集数据库中有关论文的出版情况、国家、机构、作者、知识基础与研究热点。结果:到2018年10月31日截止,研究了4 618篇论文。发表论文数:美国在国家/地区中排名第一,延世大学在研究机构中排名第一,Kwak JY在所有作者中排名第一。从2010年开始,每年发表的论文数量都在稳步增长,有相当多的论文发表在如《新英格兰杂志》、《THYROID》、《JAMA》、《CELL》等高影响因子的期刊上。甲状腺结节的SCI论文参考文献聚类为6类,分别是papillary-like nuclear feature、current statu、radiofrequency ablation、ultrasound elastography、goiter area、data system。代表研究前沿的关键词是meta-analysis、recommendation、thyroid carcinoma、shear wave elastography与bethesda system。结论:本文通过对国际上甲状腺结节的研究基础、研究热点的分析,阐述了甲状腺结节的研究趋势,为我国医学工作者的研究提供参考。  相似文献   
10.
目的针对武汉地区医院信息化系统在新型冠状病毒肺炎(简称新冠肺炎)防疫救治过程中暴露出的问题,提出应对突发公共卫生事件时医院信息化的完善方法。方法充分分析医院信息化系统在新冠肺炎防疫救治中所暴露出的各个医院信息化系统结构不同、各个医院之间无法实施信息共享、门诊病房之间系统相互独立、数据信息更新不及时等九大问题,并提出医院信息化基础布局的建立、区域链及大数据临床中的应用等多项措施。结果医院信息化能力的提高有助于降低医护人员工作强度,提高患者的安全。结论新冠肺炎疫情的发生给我国医院信息化系统带来了严峻的挑战,但同时也给我们带来了更大的机遇。我国在未来针对突发公共卫生事件时,医院信息化将为医护人员、患者提供更有利的支持。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号