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   3565篇
  免费   183篇
  国内免费   16篇
耳鼻咽喉   32篇
儿科学   40篇
妇产科学   23篇
基础医学   540篇
口腔科学   39篇
临床医学   285篇
内科学   741篇
皮肤病学   66篇
神经病学   542篇
特种医学   181篇
外科学   586篇
综合类   26篇
预防医学   160篇
眼科学   100篇
药学   230篇
中国医学   11篇
肿瘤学   162篇
  2023年   22篇
  2022年   65篇
  2021年   93篇
  2020年   55篇
  2019年   66篇
  2018年   73篇
  2017年   50篇
  2016年   85篇
  2015年   96篇
  2014年   130篇
  2013年   171篇
  2012年   229篇
  2011年   245篇
  2010年   140篇
  2009年   140篇
  2008年   212篇
  2007年   254篇
  2006年   220篇
  2005年   230篇
  2004年   193篇
  2003年   186篇
  2002年   186篇
  2001年   40篇
  2000年   26篇
  1999年   25篇
  1998年   44篇
  1997年   40篇
  1996年   31篇
  1995年   26篇
  1994年   23篇
  1993年   19篇
  1992年   13篇
  1991年   16篇
  1990年   11篇
  1989年   18篇
  1988年   16篇
  1987年   14篇
  1986年   7篇
  1985年   12篇
  1984年   10篇
  1983年   12篇
  1982年   13篇
  1981年   15篇
  1979年   6篇
  1978年   6篇
  1977年   7篇
  1976年   10篇
  1974年   6篇
  1938年   7篇
  1925年   6篇
排序方式: 共有3764条查询结果,搜索用时 15 毫秒
101.
International Journal of Colorectal Disease - The local immune contexture in patients with locally advanced rectal cancer (LARC) has important prognostic value after neoadjuvant chemoradiation and...  相似文献   
102.
103.
The incidence of most cancers increases with age. Cancer is the second most common cause of death in older adults after cardiovascular disease. Many common cancers in older adults can be prevented from occurring or can be identified at an early stage and treated effectively. The prevention and identification of cancer in its early stages, in an attempt to reduce discomfort and disability associated with advanced cancer and cancer treatment, is also a priority. Overscreening for cancer in older adults can lead to unnecessary diagnostic testing and unnecessary treatment. Both older adults and their healthcare providers need guidance on the appropriate use of cancer prevention and screening interventions. This first of a two-part review addresses special considerations regarding cancer prevention for adults aged 65 and older. Screening decisions and the impact of limited life expectancy and an older adult's ability to tolerate cancer treatment are also addressed. Guidance is provided regarding the prevention and early identification of lung, colorectal, bladder, and kidney cancer in older adults. The prevention of breast, prostate, and female urogenital cancers are addressed in Part 2. J Am Geriatr Soc 68:2399–2406, 2020.  相似文献   
104.
105.
106.
How to cite this article: Siddiqui S, Ahmed A, Azim A. Selecting Journal for Publication in the Era of “Haste Predatory Journals and COVID-19”. Indian J Crit Care Med 2020;24(12):1284–1285.  相似文献   
107.
Transforming growth factors-β1 and -β2 (TGF-β1 and -β2) are important growth-regulatory proteins for astroglial neoplasms. We analyzed their role in tumor-cell proliferation in 12 glioma cell lines, employing phosphorothioate antisense oligodeoxynucleotides (S-ODNs, 14 mer), specifically targeted against the coding sequences of TGF-β1-mRNA and TGF-β2-mRNA. TGF-β1-S-ODNs inhibited cell proliferation in 5 of 12 gliomas, whereas TGF-β2-S-ODNs reduced the cell proliferation in all glioma cell lines, compared to nonsense-S-ODN-treated and S-ODN-untreated cells as controls. The efficacy and specificity of antisense effects was validated by Northern-blot analysis and determination of protein concentrations in culture supernatants (ELISA). Exogenous hrTGF-β1 either stimulated or inhibited the cell lines, whereas pnTGF-β2 stimulated the proliferation of most glioma cells. Blocking the extracellular pathway of TGF-β by neutralizing antibodies only slightly inhibited those cell lines, which were markedly stimulated by TGF-βs. As the effects of TGF-β2-S-ODNs were much stronger than those of TGF-β neutralizing antibodies, we postulate that the endogenously produced TGF-β2 control glioma-cell proliferation, in part by an intracellular loop. © 1996 Wiley-Liss, Inc.  相似文献   
108.
Variants of the CD44 protein family containing sequences encoded by variant exon 6 (v6) are involved in the metastatic spread of rat and human tumors. The rat-specific antibody I.IASML, which recognizes a v6 epitope, interferes with metastatic dissemination of a rat pancreatic carcinoma. The single-chain antigen-binding fragment of this monoclonal antibody was fused to the ζ-chain of the T-cell receptor complex. The appropriate fusion gene was incorporated into a retroviral gene transfer vector. Murine cytotoxic T lymphocytes (CTLs) were infected, and cellular clones which express the single-chain ζ-chain fusion protein on their cell surface were selected. These CTLs are not MHC-restricted in their CD44v6 recognition and exhibit in vitro lytic activity toward cells expressing CD44 variants comprising exon v6. Tumor cell xenografts grown in athymic nude mice are suppressed in their growth upon infusion of the genetically manipulated CTLs. Our data indicate that the CD44v6 epitope is an effective target for immune tumor therapy and demonstrate the efficacy of genetically engineered CTLs in targeting tumors expressing such epitopes. © 1996 Wiley-Liss, Inc.  相似文献   
109.
110.
The 5083 and 6061(T6) aluminum (Al) alloys are widely used in transportation industries and the development of structural designs because of their high toughness and high corrosion resistance. Friction stir welding (FSW) was performed to produce the dissimilar welded joint of Al5083-Al 6061(T6) under different welding parameters. However, softening behavior occurred in the friction stir welded (FSWed) samples because of grain coarsening or the dissolution of precipitation-hardening phases in the welding zone. Consequently, this research intended to investigate the effect of the post-weld heat treatment (PWHT) method on the mechanical property improvement of the dissimilar FSWed Al5083-Al6061(T6) and governing abnormal grain growth (AGG) through different welding parameters. The results showed PWHT enhanced the mechanical properties of dissimilar joints of Al5083-Al6061(T6). AGG was obtained in the microstructure of PWHTed joints, but appropriate PWHT could recover the dissolved precipitation-hardening particle in the heat-affected zone of the as-welded joint. Further, the tensile strength of the dissimilar joint increased from 181 MPa in the as-welded joint to 270 MPa in the PWHTed joint, showing 93% welding efficacy.  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