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   6204篇
  免费   323篇
  国内免费   23篇
耳鼻咽喉   43篇
儿科学   107篇
妇产科学   86篇
基础医学   727篇
口腔科学   292篇
临床医学   504篇
内科学   1177篇
皮肤病学   120篇
神经病学   333篇
特种医学   308篇
外科学   1158篇
综合类   33篇
预防医学   147篇
眼科学   28篇
药学   456篇
中国医学   19篇
肿瘤学   1012篇
  2023年   30篇
  2022年   29篇
  2021年   90篇
  2020年   52篇
  2019年   78篇
  2018年   110篇
  2017年   94篇
  2016年   107篇
  2015年   99篇
  2014年   137篇
  2013年   158篇
  2012年   217篇
  2011年   246篇
  2010年   162篇
  2009年   168篇
  2008年   238篇
  2007年   260篇
  2006年   265篇
  2005年   264篇
  2004年   251篇
  2003年   270篇
  2002年   239篇
  2001年   236篇
  2000年   239篇
  1999年   200篇
  1998年   113篇
  1997年   93篇
  1996年   109篇
  1995年   85篇
  1994年   90篇
  1993年   83篇
  1992年   183篇
  1991年   161篇
  1990年   139篇
  1989年   159篇
  1988年   133篇
  1987年   138篇
  1986年   117篇
  1985年   114篇
  1984年   70篇
  1983年   62篇
  1982年   20篇
  1981年   29篇
  1979年   39篇
  1978年   26篇
  1977年   24篇
  1976年   21篇
  1973年   20篇
  1972年   24篇
  1970年   22篇
排序方式: 共有6550条查询结果,搜索用时 15 毫秒
31.
We report 3 cases of müllerian duct cyst. Percutaneous puncture, aspiration and instillation of a sclerosing agent under ultrasound guidance was performed in each case. Ultrasound is valuable in the diagnosis is of cysts in the region of the prostate and seminal vesicles. Aspiration under ultrasound guidance would also be of therapeutic value.  相似文献   
32.
33.
34.
Prosthetic valve endocarditis (PVE) caused by Candida species is associated with high morbidity and mortality. A combination of surgical resection and antifungal drug therapy is the golden standard for treatment, yet surgical intervention is not possible in all cases of Candida PVE. We report a case of PVE due to Candida albicans cured by medical treatment alone. This case suggests that, in some instances, Candida PVE can be managed medically with antifungal therapy. Such a conservative approach should be applied with caution and necessitates very close follow-up on a long-term basis.  相似文献   
35.
An automated on-line method for simultaneous analysis of five phenothiazine drugs by high-performance liquid chromatography (HPLC)/sonic spray ionization mass spectrometry (SSI-MS) has been established, using backflush column switching. A 400-μl portion of serum sample diluted 81-fold with distilled water was subjected to the on-line system. In the system, an Oasis HLB cartridge was used as the precolumn for extraction; large molecules such as proteins in serum were discarded by use of distilled water containing 0.1% formic acid as a mobile phase. After switching a valve, the analytes trapped in the precolumn were eluted in the backflush mode and separated by a Chromolith Performance RP-18e column, which is composed of C18-bonded monolithic silica. The column effluents were then introduced into the SSI-MS. The present method provided successful separation and determination of six phenothiazines including an internal standard. Satisfactory linearities, reproducibility, and sensitivity were obtained at concentration levels that matched the toxic levels of phenothiazines. All drug peaks appeared within 18 min, and the system could be reequilibrated in only about 8 min for the next run. Because of the simplicity and rapidness of the method, it is likely to be useful in the fields of emergency medicine and forensic toxicology.  相似文献   
36.
37.
Clinical and immunologic features of a recently recognized X-linked combined immunodeficiency disease (XCID) suggested that XCID and X-linked severe combined immunodeficiency (XSCID) might arise from different genetic defects. The recent discovery of mutations in the common gamma chain (gamma c) gene, a constituent of several cytokine receptors, in XSCID provided an opportunity to test directly whether a previously unrecognized mutation in this same gene was responsible for XCID. The status of X chromosome inactivation in blood leukocytes from obligate carriers of XCID was determined from the polymorphic, short tandem repeats (CAG), in the androgen receptor gene, which also contains a methylation-sensitive HpaII site. As in XSCID, X-chromosome inactivation in obligate carriers of XCID was nonrandom in T and B lymphocytes. In addition, X chromosome inactivation in PMNs was variable. Findings from this analysis prompted sequencing of the gamma c gene in this pedigree. A missense mutation in the region coding for the cytoplasmic portion of the gamma c gene was found in three affected males but not in a normal brother. Therefore, this point mutation in the gamma c gene leads to a less severe degree of deficiency in cellular and humoral immunity than that seen in XSCID.  相似文献   
38.
A case of papillary adenoma of type 2 pneumocytes is reported. A 57-year-old man had an unusual coin lesion in the periphery of the right lung without any symptoms. When detected in a mass survey examination, it was approximately 1.5 cm in diameter, well circumscribed, and located in S4, involving the sixth-order bronchus of B4. Light-microscopic examination revealed cuboidal tumor cells arranged in a papillary pattern. Ultrastructurally, the cells had characteristic osmiophilic lamellar bodies. By immunoperoxidase staining, the tumor cells were shown to have intracytoplasmic surfactant apoproteins. The postoperative course was uneventful, and there is no evidence of disease 8 years later.  相似文献   
39.
40.
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