全文获取类型
收费全文 | 1357761篇 |
免费 | 104918篇 |
国内免费 | 6117篇 |
专业分类
耳鼻咽喉 | 16937篇 |
儿科学 | 43863篇 |
妇产科学 | 36622篇 |
基础医学 | 200520篇 |
口腔科学 | 36447篇 |
临床医学 | 132937篇 |
内科学 | 260998篇 |
皮肤病学 | 26665篇 |
神经病学 | 112977篇 |
特种医学 | 49034篇 |
外国民族医学 | 378篇 |
外科学 | 186287篇 |
综合类 | 33917篇 |
现状与发展 | 8篇 |
一般理论 | 462篇 |
预防医学 | 116196篇 |
眼科学 | 29506篇 |
药学 | 101585篇 |
42篇 | |
中国医学 | 5466篇 |
肿瘤学 | 77949篇 |
出版年
2021年 | 12576篇 |
2019年 | 12629篇 |
2018年 | 17330篇 |
2017年 | 13297篇 |
2016年 | 14105篇 |
2015年 | 16426篇 |
2014年 | 22311篇 |
2013年 | 33396篇 |
2012年 | 46160篇 |
2011年 | 48868篇 |
2010年 | 28405篇 |
2009年 | 26013篇 |
2008年 | 43832篇 |
2007年 | 46284篇 |
2006年 | 46231篇 |
2005年 | 44557篇 |
2004年 | 42413篇 |
2003年 | 40533篇 |
2002年 | 39231篇 |
2001年 | 61588篇 |
2000年 | 62998篇 |
1999年 | 52697篇 |
1998年 | 14849篇 |
1997年 | 13581篇 |
1996年 | 13335篇 |
1995年 | 12657篇 |
1994年 | 11783篇 |
1993年 | 11009篇 |
1992年 | 41720篇 |
1991年 | 40875篇 |
1990年 | 39515篇 |
1989年 | 37401篇 |
1988年 | 34630篇 |
1987年 | 33745篇 |
1986年 | 32185篇 |
1985年 | 30665篇 |
1984年 | 23058篇 |
1983年 | 19600篇 |
1982年 | 11758篇 |
1979年 | 20814篇 |
1978年 | 14814篇 |
1977年 | 12064篇 |
1976年 | 11876篇 |
1975年 | 12110篇 |
1974年 | 14800篇 |
1973年 | 14472篇 |
1972年 | 13356篇 |
1971年 | 12418篇 |
1970年 | 11485篇 |
1969年 | 10410篇 |
排序方式: 共有10000条查询结果,搜索用时 531 毫秒
981.
Trauma und Berufskrankheit - Als schwerste Komplikation der Gelenkendoprothetik bleibt die periprothetische Infektion eine Herausforderung—heutzutage nicht nur für den Chirurgen, sondern... 相似文献
982.
U. Bolm-Audorff S. Brandenburg T. Brüning H. Dupuis R. Ellegast G. Elsner K. Franz H. Grasshoff V. Grosser L. Hanisch B. Hartmann E. Hartung K. G. Hering G. Heuchert M. Jäger J. Krämer Dr. A. Kranig E. Ludolph A. Luttmann A. Nienhaus W. Pieper K.-D. Pöhl T. Remé D. Riede G. Rompe K. Schäfer S. Schilling E. Schmitt F. Schröter A. Seidler M. Spallek M. Weber 《Trauma und Berufskrankheit》2005,7(3):211-252
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110. 相似文献
983.
乳腺影像学报告及数据系统:超声良恶性病变鉴别诊断初探 总被引:1,自引:0,他引:1
1992年美国放射学会制定了乳腺影像学报告及数据系统(breast imaging reporting and data system,BI-RADS),2003年第四版修订时包括了超声诊断(BI-RADS-US)。本文旨在初步探讨BI-RADS-US对于乳腺良恶性病变鉴别诊断的能力。我们收集了2006年1月至2007年3月期间、获得病理诊断的乳腺占位性病变共69例72灶。均为女性,年龄14-83岁,平均41.6岁。首先根据一般的非BI-RADS标准,做出良恶性鉴别。然后用BI-RADS-US标准进行鉴别和分级(0-6级),其中2级和3级为良性和良性可能性大,4级为性质待定,5级为恶性可能性大。计算并比较上述两种方法的准确性、敏感性、特异性。结果在72病灶中,根据非BI-RADS标准,诊断为良性者40灶,符合病理诊断者38灶(95.0%),诊断为恶性者23灶,符合病理者18灶(78.3%);诊断为性质待定者9灶。根据BI-RADS-US标准和分级,2级和3级共有37灶,与病理结果符合者为36灶(97.2%);5级有31灶,与病理符合者为22灶(71.0%);4级有4灶。非BI-RADS和BI-RADS-US的准确性各为83.3%和81.9%(P=1.000),敏感性各为91.7%和95.8%(P=1.000),特异性各为79.2%和75.0%(P=0.754)。总之,第一版BI-RADS-US在乳腺良恶性病变鉴别诊断方面的初步应用表现出较高的敏感性,而与非BI-RADS方法比较则尚无明显差别。 相似文献
984.
N Sverzellati F Molinari T Pirronti L Bonomo P Spagnolo M Zompatori 《INT J CHRONIC OBSTR》2007,2(3):301-312
Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD. 相似文献
985.
986.
987.
988.
Multivitamin and alcohol intake and folate receptor alpha expression in ovarian cancer. 总被引:2,自引:0,他引:2
Linda E Kelemen Thomas A Sellers Gary L Keeney Wilma L Lingle 《Cancer epidemiology, biomarkers & prevention》2005,14(9):2168-2172
Folate receptor alpha (FRalpha) expression in epithelial ovarian cancer may be related to folate intake. We examined this association using multivitamin intake, a proxy for folic acid, and assessed whether the relation was modified by alcohol intake, a folate agonist. Cases (n = 148) with suspected epithelial ovarian cancer, of ages > or = 20 years, were seen at Mayo Clinic, Minnesota, between 2000 and 2004; those with tumor specimens (n = 108) were included in analyses. Outpatient controls (n = 148) without cancer and with at least one ovary intact were matched to cases by age (within 5 years) and state of residence. Multivitamin (> or = 4 pills/wk) and weekly alcohol (> or = 5 drinks) intakes were assessed. Tumor specimens were analyzed immunohistochemically for FRalpha. Multivariable rate ratios (RR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression. In case-control analysis, the RRs of multivitamin intake with absent/weak/moderate and strong-expressing FRalpha tumors were 0.30 (95% CI, 0.12-0.70) and 0.47 (95% CI, 0.24-0.91), respectively. For alcohol, the associations were 0.84 (95% CI, 0.24-2.86) and 1.65 (95% CI, 0.69-3.93), respectively. In case-case analysis, the RR associated with developing strong-expressing versus other FRalpha tumors was 3.13 (95% CI, 1.14-8.65) for multivitamins and 1.58 (95% CI, 0.45-5.60) for alcohol. The data did not support evidence for an interaction between multivitamin and alcohol intake with risk of developing a strong-expressing FRalpha tumor. The association of multivitamin intake with ovarian cancer may depend on FRalpha expression level. 相似文献
989.
990.