全文获取类型
收费全文 | 38731篇 |
免费 | 3868篇 |
国内免费 | 228篇 |
专业分类
耳鼻咽喉 | 471篇 |
儿科学 | 1148篇 |
妇产科学 | 979篇 |
基础医学 | 5005篇 |
口腔科学 | 827篇 |
临床医学 | 4104篇 |
内科学 | 7515篇 |
皮肤病学 | 502篇 |
神经病学 | 2905篇 |
特种医学 | 1249篇 |
外国民族医学 | 9篇 |
外科学 | 4727篇 |
综合类 | 2018篇 |
现状与发展 | 1篇 |
一般理论 | 28篇 |
预防医学 | 4527篇 |
眼科学 | 972篇 |
药学 | 2930篇 |
3篇 | |
中国医学 | 421篇 |
肿瘤学 | 2486篇 |
出版年
2022年 | 292篇 |
2021年 | 684篇 |
2020年 | 422篇 |
2019年 | 547篇 |
2018年 | 602篇 |
2017年 | 590篇 |
2016年 | 507篇 |
2015年 | 653篇 |
2014年 | 945篇 |
2013年 | 1414篇 |
2012年 | 1966篇 |
2011年 | 2058篇 |
2010年 | 1279篇 |
2009年 | 1103篇 |
2008年 | 1828篇 |
2007年 | 1976篇 |
2006年 | 1814篇 |
2005年 | 1622篇 |
2004年 | 1448篇 |
2003年 | 1405篇 |
2002年 | 1365篇 |
2001年 | 1203篇 |
2000年 | 1253篇 |
1999年 | 1011篇 |
1998年 | 374篇 |
1997年 | 343篇 |
1996年 | 373篇 |
1995年 | 320篇 |
1994年 | 316篇 |
1993年 | 303篇 |
1992年 | 925篇 |
1991年 | 916篇 |
1990年 | 824篇 |
1989年 | 774篇 |
1988年 | 687篇 |
1987年 | 700篇 |
1986年 | 700篇 |
1985年 | 679篇 |
1984年 | 552篇 |
1983年 | 432篇 |
1982年 | 336篇 |
1981年 | 289篇 |
1979年 | 534篇 |
1978年 | 324篇 |
1977年 | 257篇 |
1976年 | 280篇 |
1975年 | 320篇 |
1974年 | 356篇 |
1973年 | 296篇 |
1972年 | 275篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
2.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable. 相似文献
3.
4.
沙苑子本草考证 总被引:1,自引:0,他引:1
沙苑子为我国常用中药,药用历史悠久。通过查阅本草文献,对沙苑子名称、基原、功效、产地及伪品5个方面进行考证,得知其名称演变大致经过"白蒺藜""沙苑蒺藜""沙苑子"3个阶段;历代本草记载沙苑子基原为扁茎黄芪的干燥成熟种子,古今应用品种基本一致;沙苑子补肾固精功效的记载自宋《本草衍义》起逐渐清晰明确;沙苑子道地产区自宋时起为陕西沙苑,明清时期产地逐渐转到陕西潼关、山西等地,建国后以陕西省为主向北扩散,以陕西潼关为佳;沙苑子建国前有马薸子、色微绿伪品及紫云英子等混伪品,建国后有紫云英、猪屎豆、华黄芪和直立黄芪的种子等混伪品。为沙苑子正本清源,并为其进一步深入开发提供参考。 相似文献
5.
Sarah E. Sheppard Laura Elizabeth Anderson Cathryn Sibbald Colleen Cotton Elizabeth Bhoj Marissa J. Perman Leslie Castelo‐Soccio 《Pediatric dermatology》2019,36(6):1007-1009
Epidermolysis bullosa simplex (EBS) is a skin fragility disorder resulting from mutations of structural proteins in the epidermis. We provide a brief report of long‐term survival and reproduction in a mother with EBS due to keratin 5 (KRT5) c.1429G > A (p.E477K) mutation, which causes a particularly severe form of the disease. 相似文献
6.
7.
8.
Elizabeth A. Mosley PhD MPH Amy J. Schulz PhD MPH MSW Lisa H. Harris MD PhD Barbara A. Anderson PhD 《Women & health》2020,60(7):806-820
ABSTRACT Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood. 相似文献
9.
目的 探讨腰硬联合(CSEA)及患者自控镇痛(PCEA)对产程及分娩结局的影响。方法 随机选取2014年1~12月足月待产、无妊娠合并症和并发症初产妇996例,其中503例产妇于活跃期实施CSEA+PCEA镇痛(分娩镇痛组),493例未行分娩镇痛(对照组),分别记录并比较两组产妇各产程时间、子宫收缩、镇痛效果、运动神经阻滞程度、产程中缩宫素的使用率、产后出血率、羊水Ⅲ度污染率、新生儿Apgar评分、产钳助产和剖宫产率。结果 分娩镇痛组第一产程、第二产程较对照组有所延长,差异有统计学意义(P<0.05);第三产程无明显改变;子宫收缩力减弱;分娩镇痛组较对照组镇痛效果显著,差异有统计学意义(P<0.05);运动阻滞程度低;缩宫素使用率、产后出血率、羊水Ⅲ度污染率、及新生儿Apgar评分及产钳助产和剖宫产率两组比较,差异均无统计学意义(P>0.05)。结论 腰硬联合分娩镇痛可能会使第一产程、第二产程延长,对子宫收缩力有一定的影响,但并未增加缩宫素的使用率及产钳助产和剖宫产率,其镇痛效果显著,运动阻滞程度低,对分娩结局无不良影响。 相似文献
10.
Joseph D. Westaby Susanna T. E. Cooper Khari A. Edwards Robert H. Anderson Mary N. Sheppard 《Clinical anatomy (New York, N.Y.)》2020,33(3):394-404
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc. 相似文献