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   3675篇
  免费   238篇
  国内免费   4篇
耳鼻咽喉   31篇
儿科学   60篇
妇产科学   54篇
基础医学   524篇
口腔科学   65篇
临床医学   308篇
内科学   894篇
皮肤病学   95篇
神经病学   400篇
特种医学   80篇
外科学   441篇
综合类   10篇
一般理论   3篇
预防医学   291篇
眼科学   24篇
药学   235篇
中国医学   8篇
肿瘤学   394篇
  2023年   20篇
  2022年   54篇
  2021年   154篇
  2020年   62篇
  2019年   133篇
  2018年   149篇
  2017年   89篇
  2016年   80篇
  2015年   88篇
  2014年   146篇
  2013年   194篇
  2012年   289篇
  2011年   285篇
  2010年   171篇
  2009年   145篇
  2008年   206篇
  2007年   177篇
  2006年   188篇
  2005年   183篇
  2004年   148篇
  2003年   142篇
  2002年   142篇
  2001年   79篇
  2000年   61篇
  1999年   61篇
  1998年   29篇
  1997年   34篇
  1996年   19篇
  1995年   21篇
  1994年   22篇
  1993年   15篇
  1992年   54篇
  1991年   46篇
  1990年   30篇
  1989年   28篇
  1988年   21篇
  1987年   15篇
  1986年   23篇
  1985年   18篇
  1984年   11篇
  1982年   5篇
  1981年   5篇
  1979年   12篇
  1977年   6篇
  1976年   5篇
  1975年   4篇
  1973年   4篇
  1972年   4篇
  1971年   5篇
  1933年   4篇
排序方式: 共有3917条查询结果,搜索用时 15 毫秒
1.
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a...  相似文献   
2.
3.
L Grau 《Women & health》1988,14(3-4):75-91
Currently it is estimated that up to 25 percent of the elderly manifest symptoms of mental disorder. The recognition of the seriousness of the problem has lead to a growing body of research in the field of geriatric mental health. This paper presents an overview of early gerontological studies of life satisfaction and morale of older persons and of the two most prevalent mental health problems of the aged, depression and dementia. Mental health service delivery and utilization issues are also considered.  相似文献   
4.
The atomic rearrangement cascade that follows the electron-capture decay process in low-Z radionuclides involves X-rays which have high photoelectric interaction probabilities. When the K-shell binding energy of the ionized atom (e.g., hydrogen) is significantly lower than the energy of the X-ray photon, the detector response to a photon-equivalent energy electron and the whole photoionization process are very similar. This is not the case when the scintillator cocktail contains larger atoms (e.g., oxygen and phosphorus in Ultima Gold). For larger Z atoms, the reduced energy of the whole photoionization process is less than the reduced energy of the interacting photon due to the nonlinear effects of ionization quenching. This paper shows the convenience of including a more detailed simulation of the photoionization process in the atomic rearrangement detection model for electron-capture nuclides such as (55)Fe, (51)Cr and (54)Mn. The need for more elaborate atomic rearrangement models is a consequence of the analysis of (125)I data.  相似文献   
5.
Reports of a dramatic decrease in tumor recurrence and regression of muscle invasive disease with oral bacillus Calmette-Guerin prompted us to conduct a randomized prospective comparison of oral bacillus Calmette-Guerin with the standard intravesical plus percutaneous therapy. Oral therapy consisted of 200 mg. Tice bacillus Calmette-Guerin 3 times each week. Intravesical and percutaneous Tice bacillus Calmette-Guerin at a dose of 50 mg. was given weekly for 6 weeks, at 8, 10 and 12 weeks, then at 6 months and every 6 months thereafter. Minimal side effects confirmed the safety of oral bacillus Calmette-Guerin. Tumor recurrence was documented in 21 of 33 oral bacillus Calmette-Guerin patients (64%) and 18 of 55 (33%) who received intravesical plus percutaneous therapy (p less than 0.002, chi-square test). We were unable to demonstrate any antitumor activity of oral bacillus Calmette-Guerin in this study.  相似文献   
6.
The treatment of neoplasia with interleukin-2 (IL-2) can be complicated by neurological deficits resembling transient Ischemic attack and stroke. We investigated whether interleukin-2 contributes to the natural course of cerebrovascular ischemia and particularly to the pathogenesis of infection-associated stroke. Plasma levels of interleukin-2 were below the level of detectability in almost all measurements. Patients with and without previous infection (n = 11, 805 ±445 U/ml vs n = 19, 824 ± 501 U/ml) did not have significantly higher levels of soluble interleukin-2 receptors than control subjects with (n = 14, 667 ± 229 U/ml) or without vascular risk factors (n = 17, 567 ± 176 U/ml). Receptor levels increased in patients during the first week after stroke (n = 15, 1157 ± 1013, p < 0.02). Levels of soluble T8 antigen (sT8) were higher in patients (n – 26, 320 ± 112 U/ml) than in healthy control subjects (n = 15, 246 ± 92 U/ml; p < 0.05) and sT8 levels increased during the first week after stroke (p < 0.05). These results reflect an immunological response to the cerebral infarct; they do not indicate a general role of the IL-2 system in the pathogenesis of ischemic stroke with or without previous infection.  相似文献   
7.
8.
A strong correlation exists between the presence of specifictypes of human papillomavirus (HPV) and the development of anogenitalcancer, as well as significant epidemiologic evidence suggestingsmokers are at increased risk of developing cervical, vulvarand/or anal carcinomas. Primary and human papillomavirus type18 (HPV-8)-immortalized human keratinocytes were used to addressthe co-carcinogenic potential of HPV and nitrosomethylurea (NMU)in tumorigenesis. Only cells containing HPV-18 and treated withNMU and the tumor-promoting phorbol ester, TPA, were transformedto a malignant phenotype. An in vitro system is described whichinitiates studies involving the mechanisms of HPV and chemicalcarcinogen co-operation in the etiology of squamous cell carcinomas.  相似文献   
9.
The synthesis and evaluation of a new class of diuretic agents derived from the pyrazino[2,3-c][1,2,6]thiadiazine 2,2-dioxide ring system are described. Preliminary structure-activity relationships indicate that the nature and location of the substituents at different positions of the heterocycle are crucial for activity. Thus, a novel synthetic methodology has been developed to selectively introduce the desired substituents at different positions. From the study of the pharmacological properties (dose-response curves, duration of action, and acute toxicity) of the most active compounds, 4-amino-1,7-diethyl-6-methylpyrazino[2,3-c][1,2,6]thiadiazine++ + 2,2-dioxide (9) was selected for further investigation. Compound 9 (C10H15N5O2S) crystallizes in space group P21/a with unit cell dimensions a = 16.482 (1), b = 9.3484 (3), c = 8.333 (3) A, beta = 103.003 (3) degrees, Z = 4.  相似文献   
10.
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