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   1074篇
  免费   86篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   20篇
妇产科学   17篇
基础医学   155篇
口腔科学   16篇
临床医学   141篇
内科学   281篇
皮肤病学   34篇
神经病学   51篇
特种医学   30篇
外科学   144篇
综合类   17篇
预防医学   78篇
眼科学   30篇
药学   69篇
中国医学   13篇
肿瘤学   62篇
  2023年   16篇
  2022年   51篇
  2021年   76篇
  2020年   56篇
  2019年   66篇
  2018年   60篇
  2017年   34篇
  2016年   40篇
  2015年   46篇
  2014年   71篇
  2013年   67篇
  2012年   118篇
  2011年   95篇
  2010年   48篇
  2009年   34篇
  2008年   48篇
  2007年   46篇
  2006年   38篇
  2005年   34篇
  2004年   21篇
  2003年   21篇
  2002年   15篇
  2001年   2篇
  2000年   5篇
  1999年   7篇
  1998年   3篇
  1997年   2篇
  1996年   3篇
  1995年   4篇
  1992年   3篇
  1989年   3篇
  1988年   2篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   3篇
  1972年   3篇
  1971年   2篇
  1970年   1篇
  1967年   1篇
排序方式: 共有1163条查询结果,搜索用时 15 毫秒
91.
92.
Comparing lymphocyte responses to allergenic and nonallergenic foods could reveal the differences between pathogenic and normal immune responses to foods. Defining the cytokine-producing phenotypes of peanut-specific lymphocytes from peanut-allergic children, children who outgrew peanut allergy, and children who have always tolerated peanuts may be useful for understanding the mechanisms of food tolerance. Investigating immune responses against foods is hindered, however, by the fact that circulating food antigen-specific lymphocytes are very rare. In a novel approach we used carboxyfluorescein succinimidyl ester to detect peanut-specific lymphocytes by flow cytometry. We confirmed that these cells are indeed peanut specific by cloning. Peanut-allergic donors show Th2 polarization of cytokine production by peanut-specific cells (IFN-gamma (low), TNF-alpha (low), IL-4 (high), IL-5 (high), IL-13 (high)). Conversely, nonallergic children and children who have outgrown their allergy show Th1 skewing to peanut antigens (IFN-gamma(high), TNF-alpha (high), IL-4 (low), IL-5 (low), IL-13(low)), similarly to nonallergenic food antigens (beta-lactoglobulin, OVA). This finding suggests that peanut antigens do not intrinsically induce Th2 skewing, but that the type of response depends upon the donor's allergic status. In conclusion, food allergic status is characterized by a Th2 response whereas Th1-skewed responses underlie oral tolerance.  相似文献   
93.
94.
One hundred and thirty-six men with coronary artery disease were randomly assigned to a hospital-based or home-based exercise program of 3 sessions per week. A treadmill test was carried out with the modified Naughton protocol. After 3 months, 125 patients (92%) with a mean age of 55 +/- 11 years had completed the study. Maximum workload achieved increased by 65% [(12.40 +/- 1.32 vs. 7.50 +/- 0.85 metabolic equivalent units (METs)] in the hospital-based group, and by 17% (8.86 +/- 0.9 vs. 7.56 +/- 0.78 METs) in the home-based group ( p = 0.0001). The heart rate-blood pressure product, an index of myocardial oxygen consumption, decreased at rest by 19% in the hospital-based group but was unchanged in the home-based group ( p = 0.0001). The heart rate-blood pressure product at 5 and 7 METs activity level decreased 28% and 26%, respectively, in the hospital-based group vs. 8% and 2% in the home-based group ( p = 0.0001). It was concluded that hospital-based exercise training in patients with coronary artery disease improves functional capacity and decreases the myocardial oxygen consumption index at rest and during exercise.  相似文献   
95.
96.
97.
Early and accurate diagnosis and treatment of rheumatoid arthritis (RA) improves disease outcome. Anti-cyclic citrullinated peptide antibody (anti-CCP) which is highly specific for RA is produced locally from inflamed synovium. The present study was designed to assess the diagnostic performance of synovial fluid anti-CCP (sf-CCP) for RA. A total of 128 patients consisted of 37 RA confirmed by the American College of Rheumatology revised criteria, 91 non-RA (50 non-RA inflammatory arthritis and 41 osteoarthritis) entered the study. Serum anti-CCP (sm-CCP) and Sf-CCP were measured by the ELISA method. Receiver operating characteristics curves were constructed to determine the optimal cutoff point levels for sf-CCP and sm-CCP to discriminate RA from non-RA. Diagnostic characteristics of both variables were determined by comparison of RA patients with non-RA controls. Mean levels of sf-CCP and sm-CCP were significantly higher in RA than in non-RA (P < 0.001). Sf-CCP discriminated RA from non-RA at the optimal cutoff value of 10 U/mL with high accuracy at AUC value of 0.897 ± 0.039, P < 0.001) sensitivity of 83.7% and specificity of 95.6%. Sm-CCP diagnosed RA at optimal cutoff level of 14.6 U/mL with respective sensitivity, specificity and AUC values of 84.8, 94.3% and 0.895 ± 0.049, P < 0.001). Sm-CCP was strongly correlated with sf-CCP (r = 0.75, r 2 = 0.57, P < 0.0001). Two of 5 sm-CCP negative RA and 25.7% of serum rheumatoid factors negative RA were sf-CCP positive. These findings indicate that sf-CCP yields diagnostic ability as comparable as sm-CCP for RA. Respecting to local production of sf-CCP prior to disease onset, therefore sf-CCP determination may offer earlier as well as additional diagnostic information which may be more helpful in recognizing RA particularly among recent onset arthritis.  相似文献   
98.
Non-thermal atmospheric pressure dielectric barrier discharge (DBD) plasma may provide a novel approach to treat malignancies via induction of apoptosis. The purpose of this study was to evaluate the potential of DBD plasma to induce apoptosis in melanoma cells. Melanoma cells were exposed to plasma at doses that did not induce necrosis, and cell viability and apoptotic activity were evaluated by Trypan blue exclusion test, Annexin-V/PI staining, caspase-3 cleavage, and TUNEL? analysis. Trypan blue staining revealed that non-thermal plasma treatment significantly decreased the viability of cells in a dose-dependent manner 3 and 24 h after plasma treatment. Annexin-V/PI staining revealed a significant increase in apoptosis in plasma-treated cells at 24, 48, and 72 h post-treatment (p < 0.001). Caspase-3 cleavage was observed 48 h post-plasma treatment at a dose of 15 J/cm(2). TUNEL? analysis of plasma-treated cells demonstrated an increase in apoptosis at 48 and 72 h post-treatment (p < 0.001) at a dose of 15 J/cm(2). Pre-treatment with N-acetyl-L: -cysteine (NAC), an intracellular reactive oxygen species (ROS) scavenger, significantly decreased apoptosis in plasma-treated cells at 5 and 15 J/cm(2). Plasma treatment induces apoptosis in melanoma cells through a pathway that appears to be dependent on production of intracellular ROS. DBD plasma production of intracellular ROS leads to dose-dependent DNA damage in melanoma cells, detected by γ-H2AX, which was completely abrogated by pre-treating cells with ROS scavenger, NAC. Plasma-induced DNA damage in turn may lead to the observed plasma-induced apoptosis. Since plasma is non-thermal, it may be used to selectively treat malignancies.  相似文献   
99.
100.
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