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   14830篇
  免费   1560篇
  国内免费   561篇
耳鼻咽喉   80篇
儿科学   475篇
妇产科学   658篇
基础医学   4207篇
口腔科学   246篇
临床医学   1010篇
内科学   2260篇
皮肤病学   251篇
神经病学   1054篇
特种医学   173篇
外国民族医学   2篇
外科学   689篇
综合类   1460篇
现状与发展   3篇
一般理论   10篇
预防医学   1393篇
眼科学   224篇
药学   987篇
  2篇
中国医学   558篇
肿瘤学   1209篇
  2024年   20篇
  2023年   352篇
  2022年   258篇
  2021年   592篇
  2020年   647篇
  2019年   660篇
  2018年   554篇
  2017年   549篇
  2016年   615篇
  2015年   661篇
  2014年   866篇
  2013年   1166篇
  2012年   767篇
  2011年   922篇
  2010年   714篇
  2009年   828篇
  2008年   785篇
  2007年   736篇
  2006年   752篇
  2005年   582篇
  2004年   509篇
  2003年   453篇
  2002年   417篇
  2001年   333篇
  2000年   229篇
  1999年   195篇
  1998年   165篇
  1997年   130篇
  1996年   141篇
  1995年   174篇
  1994年   112篇
  1993年   99篇
  1992年   113篇
  1991年   84篇
  1990年   77篇
  1989年   76篇
  1988年   57篇
  1987年   59篇
  1986年   70篇
  1985年   75篇
  1984年   57篇
  1983年   54篇
  1982年   47篇
  1981年   53篇
  1980年   52篇
  1979年   36篇
  1978年   19篇
  1977年   5篇
  1976年   19篇
  1973年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
The representation of nursing faculty of color is disproportionate to that in the general population, despite recruitment and retention strategies. Boosting the presence of nursing faculty of color requires an understanding of factors that undermine diversity initiatives and calls for the adoption of innovative practices. This article addresses the importance of racial and ethnic diversity within nursing education. Furthermore, it examines the factors that prevent the recruitment and retention of a racially and ethnically diverse nursing faculty workforce and provides evidence-based recommendations for increasing diversity among nursing faculty and nursing organizations.  相似文献   
2.
3.
4.

Objective

To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.

Data Source

Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.

Study Design

We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.

Principal Findings

In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.

Conclusions

Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships.  相似文献   
5.
目的 利用筛选出十堰的天师栗中高多态性SSR位点评价天师栗种质资源的遗传多样性,结合有效药用成分含量,构建十堰地区天师栗核心种质库。方法 收集十堰地区114份天师栗种质资源,以七叶树基因组为参考,采用荧光毛细管电泳筛选出高多态性SSR位点,对天师栗种质资源进行遗传多样性分析。利用HPLC测定不同种质干燥娑罗子中七叶皂苷的含量。采用最小距离逐步聚类取样策略(LDSS),根据遗传多样性保留程度初步筛选出核心种质,并对该核心种质与原始种质的遗传多样性参数进行T检验,选择与原种质差异不显著的核心种质为最佳核心种质。结果 筛选出13对高多态性SSR分子标记,遗传多样性评价结果表明十堰地区天师栗种质资源遗传多样性较高,遗传分化较小,存在着较大的基因流,114份种质资源未分为不同的亚群,周家坝和辽叶居群间具有较近的遗传亲缘关系,且周家坝居群娑罗子中的七叶皂苷A及七叶皂苷B含量普遍较高。最终筛选出的核心种质共23份,占总种质资源的20.17%,其中周家坝12份样本、辽叶6份样本、普龄5份样本。结论 将SSR分子标记与主要有效药用成分结合,采用LDSS取样策略构建十堰地区天师栗种质资源核心种质库的方法具有可行性,能够有效的保存与管理天师栗种质资源,也为当地天师栗品种改良、新品种选育研究等提供了研究基础。  相似文献   
6.
Evidence exists that women and people from low- and middle-income countries are under-represented on the editorial boards of medical journals. This may adversely influence the journal output. We conducted a pooled, cross-sectional evaluation of the editorial board membership of anaesthesia journals. We collected data on members of editorial boards from the founding year and at 5-yearly intervals until 2020. For each editor, we recorded gender, country of affiliation, World Bank income classification (1990 onwards) and editorial role (2020 only). The composite editorial board diversity score was calculated for each editorial board. We obtained complete data for the composition of editorial boards from all 30 journals for 2020, but for only 171 out of 304 editorial boards (56%) over the time period examined. In 2020, 409 out of 1973 (21%) were women (range across the editorial boards 0–39%) and 139 out of 1982 (7%) were from low-, low-middle- and upper-middle-income countries (range across the editorial boards 0–71%). In 2020, of editorial board positions with known seniority status, 109 out of 259 (42%) of women and 306 out of 960 (32%) of men were in senior roles. In the same year, 397 out of 1115 (36%) of people from high-income countries were in senior roles, compared with 19 out of 93 (20%) of people from upper-middle-income countries and 0 out of 14 (0%) people from lower-middle-income countries. The median composite editorial board diversity score was 4 (range 2–6) in 2020 – 5 or less suggests poor diversity, while 8 or more suggests good diversity. Women and people from low- and middle-income countries are under-represented on anaesthesia journal editorial boards. The editorial boards do not reflect the anaesthesia workforce and may act as a barrier to the publication of research produced by these groups. Urgent action is required to improve diversity.  相似文献   
7.
8.
目的:调查药食两用薏苡仁中污染真菌多样性,为其安全使用提供参考依据。方法:收集薏苡仁样品18批,提取真菌DNA并扩增ITS2序列,基于Illumina MiSeq PE250平台进行高通量测序。结果:共检测到4门18纲44目99科149属的真菌,子囊菌门Ascomycota是最优势菌门,镰刀菌属Fusarium(3.05%~60.32%)是属水平最优势属,其次是曲霉属Aspergillus(2.20%~45.44%)、白僵菌属Beauveria(0.07%~63.21%)、链格孢属Alternaria(0.80%~11.92%)、Arachnomyces(0.03%~39.36%)和青霉属Penicillium(0.24%~8.03%)。此外,共检测到5种潜在产毒真菌,分别是烟曲霉A.fumigatus、土曲霉A.terreus、梨孢镰刀菌F.poae、囊状青霉P.capsulatum和展青霉P.paxilli。结论:高通量测序技术可以快速有效地检测薏苡仁中污染真菌种类,为薏苡仁污染真菌毒素提供风险预警。  相似文献   
9.
目的:利用简单序列重复区间扩增多态性(ISSR)分子标记技术对江西省锐尖山香圆进行亲缘关系和遗传结构分析,为该药材资源的保护和利用提供理论依据。方法:采集江西省4个县6个采样地的22份锐尖山香圆叶片样本,利用试剂盒法提取基因组DNA。利用64条通用ISSR分子标记引物进行聚合酶链式反应(PCR)扩增,运用聚丙烯酰胺凝胶电泳(PAGE)方法检测条带。选择NTsys 2. 10e软件,采用非加权配对算术平均法(UPGMA)计算遗传相似系数并聚类分析。利用Structure 2. 1软件分析群体遗传结构。结果:有48条ISSR引物扩增后获得了产物,多态性条带百分率处于45. 45%~100%。UPGMA聚类分析表明4个县的锐尖山香圆资源不能按照行政区域划分分别聚为一类,群体遗传结构分析表明22份锐尖山香圆群体可以划分为3个类群。结论:江西省锐尖山香圆群体间存在着基因交流,会影响该药材不同地理来源种质资源的遗传结构组成。  相似文献   
10.
目的研究某院耐碳青霉烯类肠杆菌科细菌(CRE)在细菌耐药方面的分子流行病学特征,为CRE的防控提供依据。方法收集某院2013—2017年细菌室保存的CRE,对其进行多位点序列分型(MLST)、药敏试验、全基因序列测定,选取部分CRE中携带的碳青霉烯耐药基因进行基因环境分析。结果共收集62株CRE,成功复活51株;其中耐碳青霉烯类肺炎克雷伯菌(CRKP)30株,耐碳青霉烯类大肠埃希菌(CREC)9株,耐碳青霉烯类阴沟肠杆菌(CRECL)6株,耐碳青霉烯类其他肠杆菌6株。CRKP MLST主要包括3株ST147、2株ST11;CREC MLST主要包括3株ST167;CRECL MLST主要包括3株ST93、2株ST88。51株CRE对氨苄西林、头孢噻肟的耐药率最高,均为100%。耐碳青霉烯类耐药基因分布:1株携带blaKPC-2,14株携带blaIMP-4,18株携带blaNDM-1,22株携带blaNDM-5,2株携带blaNDM-9,10株携带blaOXA-1,10株携带blaOXA-10,2株携带blaOXA-23,2株携带blaOXA-66。分析blaNDM-1、blaNDM-5、blaNDM-9、blaIMP-4不同菌种的基因环境,发现几种耐药基因各自的基因环境都与已报道的基因环境相似,无明显的菌种间差异性。结论耐药基因通过水平传播能稳定存在于不同的CRE菌株中,对医院感染防控造成一定的威胁。  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