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   5888篇
  免费   300篇
  国内免费   18篇
耳鼻咽喉   87篇
儿科学   512篇
妇产科学   162篇
基础医学   588篇
口腔科学   65篇
临床医学   388篇
内科学   1354篇
皮肤病学   309篇
神经病学   213篇
特种医学   333篇
外科学   874篇
综合类   91篇
一般理论   5篇
预防医学   212篇
眼科学   71篇
药学   370篇
中国医学   29篇
肿瘤学   543篇
  2023年   37篇
  2022年   85篇
  2021年   180篇
  2020年   85篇
  2019年   142篇
  2018年   169篇
  2017年   122篇
  2016年   158篇
  2015年   174篇
  2014年   229篇
  2013年   291篇
  2012年   421篇
  2011年   480篇
  2010年   278篇
  2009年   263篇
  2008年   338篇
  2007年   344篇
  2006年   332篇
  2005年   335篇
  2004年   290篇
  2003年   217篇
  2002年   228篇
  2001年   56篇
  2000年   64篇
  1999年   59篇
  1998年   49篇
  1997年   49篇
  1996年   41篇
  1995年   29篇
  1994年   30篇
  1993年   24篇
  1992年   38篇
  1991年   53篇
  1990年   60篇
  1989年   49篇
  1988年   47篇
  1987年   44篇
  1986年   33篇
  1985年   41篇
  1984年   32篇
  1983年   14篇
  1982年   11篇
  1981年   19篇
  1980年   11篇
  1979年   20篇
  1978年   13篇
  1976年   11篇
  1974年   12篇
  1973年   16篇
  1972年   10篇
排序方式: 共有6206条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.
Mirror movements are simultaneous, involuntary, identical movements occurring during contralateral voluntary movements. These movements are considered as soft neurologic signs seen uncommonly in clinical practice. The mirror movements are described in various neurological disorders which include parkinsonism, cranio veretebral junction anamolies, and hemiplegic cerebral palsy. These movements are intriguing and can pose significant disability. However, no such observation regarding mirror movements in progressive hemifacial atrophy have been reported previously. We are reporting a teenage girl suffering from progressive hemifacial atrophy and epilepsy with demonstrable mirror movements in hand.  相似文献   
5.
6.
7.
BACKGROUND: We prospectively evaluated the usefulness of IgA tissue transglutaminase antibodies (IgA tTG) in the initial diagnosis of celiac disease (CD) and compared its diagnostic potential with that of IgA anti-endomysial antibodies (IgA EMA) and anti-IgA and IgG gliadin antibodies (AGA and AGG, respectively). METHODS: Sera of 23 untreated children fulfilling the revised ESPGHAN criteria for diagnosis of CD (Group I; mean age 10.8 y); 19 disease controls (Group II; mean age 8.5 y) presenting with chronic diarrhea, short stature or both; and 22 healthy children (Group III; mean age 8.8 y) were studied. These were tested in a blinded manner for AGA, AGG, IgA tTG (guinea pig as antigen) and IgA EMA. RESULTS: In Group I, IgA EMA was positive in 19, IgA tTG in 17, AGA in 14 and AGG in 17 patients. In Group II, these tests were positive in 1, 0, 2 and 14 patients, respectively and in Group III, in 0, 0, 0 and 1 child, respectively. Analyzing data from Group I and II, IgA EMA, IgA tTG, AGA and AGG had sensitivity rates of 83%, 74%, 61% and 74%, respectively; the specificity rates were 95%, 100%, 89% and 26%; positive predictive values were 95%, 100%, 88% and 55% and negative predictive values were 82%, 74%, 65% and 45%, respectively. CONCLUSION: IgA tTG is useful for the diagnosis of CD, with sensitivity and specificity rates comparable to those of EMA and this test is well suited for use in tropical countries like India.  相似文献   
8.
Sixty drinking water samples collected from various sources in different areas of Delhi during epidemic of cholera and gastroenteritis were analysed for bacteriological standards. Only 27 (45 per cent) samples were found to be satisfactory for human consumption. Remaining thirty-three (55 per cent) samples showed presence of coliform organisms with MPN value ranging from 10 to 1800+ per 100 ml. Among these positive samples, 31 (93.9 per cent) samples contained faecal coli. Twenty out of thirty (66.6 per cent) Hand pump, 9 out of 21 (42.8 per cent) Taps 2 out of 4 (50 per cent) Tube well and 2 out of 5 (40 per cent) of miscellaneous sources showed contamination with coliform organisms.  相似文献   
9.
Studies have demonstrated that lipid rafts ultimately regulate the endocytosis of anthrax toxin via clathrin dependent pathway. Interestingly, GPI-anchored protein rich rafts have also been shown to be transported down to the endocytic pathway to reducing late endosomes. Taking advantage of this parallelism, we tried translating the anthrax toxin natural intoxication mechanism by administering a DNA chimera that encoded protective antigen attached to a mammalian GPI-anchor sequence at its C-terminus (pGPI-PA63). We also designed a chimera that had an additional N-terminal TPA leader sequence (pTPA.GPI-PA63) with an aim to target GPI-PA63 to ER where new CD1 molecules are synthesized. Analysis of antibody titers demonstrated successful priming and potential IgG titers after the first boost. In vitro cell proliferation studies in the presence of GPI-attached PA63 peptides revealed that there was a clonal expansion of CD4+ NK1.1+ helper T cell population which rapidly produced IL-4 in response to T cell receptor ligation. These cells provided direct B cell help that aided IgG formation. Effector responses generated by NKT cells were found to be MHC II-independent and CD1d-restricted. In addition, the group pTPA.GPI-PA63 also displayed low magnitude MHC-II restricted (CD1d-independent) NKT cell and CD4+ T cell helper responses in response to non-GPI attached PA63 peptides which overall resulted in the heightened responses seen for this group. Importantly, DNA vaccination mediated the generation of high avidity neutralizing antibodies that mediated protection against lethal toxin challenge.  相似文献   
10.
Brain metastasis is the most common intracranial malignancy in adults. Improvements in modern imaging techniques are detecting previously occult brain metastases, and more effective therapies are extending the survival of patients with invasive cancer who have historically died from extracranial disease before developing brain metastasis. This combination of factors along with increased life expectancy has led to the increased diagnosis of brain metastases. Conventional treatment has been whole brain radiotherapy, which can improve symptoms, but potentially results in neurocognitive deficits. Several strategies to improve the therapeutic ratio are currently under investigation to either enhance the radiation effect, thereby preventing tumor recurrence or progression as well as reducing collateral treatment-related brain injury. In this review article, we discuss new directions in the management of brain metastases, including the role of chemical modifiers, novel systemic agents, and the management and prevention of neurocognitive deficits.  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