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   13941篇
  免费   704篇
  国内免费   101篇
耳鼻咽喉   95篇
儿科学   353篇
妇产科学   92篇
基础医学   1728篇
口腔科学   384篇
临床医学   782篇
内科学   3667篇
皮肤病学   549篇
神经病学   942篇
特种医学   590篇
外科学   2358篇
综合类   48篇
预防医学   450篇
眼科学   276篇
药学   1122篇
中国医学   24篇
肿瘤学   1286篇
  2023年   76篇
  2022年   58篇
  2021年   261篇
  2020年   157篇
  2019年   209篇
  2018年   283篇
  2017年   215篇
  2016年   234篇
  2015年   245篇
  2014年   332篇
  2013年   448篇
  2012年   682篇
  2011年   751篇
  2010年   448篇
  2009年   376篇
  2008年   684篇
  2007年   760篇
  2006年   720篇
  2005年   828篇
  2004年   802篇
  2003年   822篇
  2002年   848篇
  2001年   353篇
  2000年   393篇
  1999年   375篇
  1998年   197篇
  1997年   155篇
  1996年   173篇
  1995年   131篇
  1994年   126篇
  1993年   103篇
  1992年   230篇
  1991年   194篇
  1990年   207篇
  1989年   192篇
  1988年   182篇
  1987年   170篇
  1986年   149篇
  1985年   146篇
  1984年   126篇
  1983年   101篇
  1982年   48篇
  1981年   59篇
  1979年   71篇
  1978年   62篇
  1977年   54篇
  1973年   55篇
  1971年   44篇
  1969年   54篇
  1968年   52篇
排序方式: 共有10000条查询结果,搜索用时 245 毫秒
1.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  相似文献   
2.

Background

On April 1, 2016, the Ministerial ordinance was enforced, and musculoskeletal examination of the extremities was made mandatory. From 2008, the University of us started musculoskeletal direct examination. To expand the examination, from 2016, we started to use the marksheet-type questionnaire. This study aimed to report the results of a musculoskeletal examination and investigate the association between musculoskeletal examination and age/gender and reports the reliability of the collected questionnaire data.

Methods

Direct musculoskeletal examination was performed in K school by 7 orthopedic surgeons. A marksheet-type screening questionnaire was distributed to all the elementary and junior high school students in Tsukuba and Hitachiomiya cities. The rates of abnormal findings for scoliosis, standing flexion, full squatting with the heels on the floor, general joint laxity, and standing on one leg, torticollis, and flat feet were calculated. We compared the results of the questionnaire and direct examination and calculated sensitivity, specificity, and odds ratio.

Results

A total of 1844 students in K school had direct examination, and 22,494 questionnaires were able to correct in Tsukuba and Hitachiomiya cities. The rates of abnormal findings in direct examination/questionnaire in scoliosis, standing flexion, full squat, general joint laxity, standing on one leg, torticollis and flat foot were 18.7% (344/1842)/5.1% (1094/21441), 20.2% (372/1841)/26.6% (5817/22078), 6.2% (114/1832)/6.9% (1516/22101), 7.5% (1648/22252), 4.9% (1100/22077), 2.2% (31/1844)/1.2% (272/21687), and 12.5% (231/1842)/8.7% (1785/20871), respectively. Sensitivities of the questionnaire for scoliosis, stand flexion, full squatting, torticollis, and flat feet were 16.8% (53/316), 67.9% (250/368), 48.2% (55/114), 18.9% (7/37), and 32.2% (65/202), respectively.

Conclusion

We reported the result of musculoskeletal examination. Accuracy and reliability of this questionnaire were not satisfactory. To perform high quality musculoskeletal examinations, we will aim to increase the quality of screening methods.  相似文献   
3.
4.
5.
    
  相似文献   
6.
7.
8.
9.
10.
The contents of free and conjugated polyamines in cyst fluids of brain tumours were analysed. The putrescine and N1-acetylspermidine levels in cyst fluids of malignant brain tumours were significantly higher than those of benign tumours. The free spermidine levels in malignant and benign tumours were about the same, while the total spermidine levels were higher in malignant than those in benign tumours. These results suggest that polyamine levels in cyst fluids reflect the altered polyamine metabolism in brain tumours.  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