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   4407篇
  免费   208篇
  国内免费   16篇
耳鼻咽喉   40篇
儿科学   119篇
妇产科学   168篇
基础医学   567篇
口腔科学   64篇
临床医学   309篇
内科学   1254篇
皮肤病学   52篇
神经病学   313篇
特种医学   163篇
外科学   640篇
综合类   13篇
一般理论   1篇
预防医学   85篇
眼科学   106篇
药学   264篇
中国医学   6篇
肿瘤学   467篇
  2023年   19篇
  2022年   42篇
  2021年   94篇
  2020年   41篇
  2019年   70篇
  2018年   80篇
  2017年   75篇
  2016年   79篇
  2015年   82篇
  2014年   96篇
  2013年   135篇
  2012年   237篇
  2011年   233篇
  2010年   117篇
  2009年   103篇
  2008年   205篇
  2007年   228篇
  2006年   222篇
  2005年   197篇
  2004年   226篇
  2003年   183篇
  2002年   189篇
  2001年   155篇
  2000年   179篇
  1999年   114篇
  1998年   46篇
  1997年   28篇
  1996年   31篇
  1995年   19篇
  1994年   30篇
  1993年   27篇
  1992年   95篇
  1991年   101篇
  1990年   102篇
  1989年   99篇
  1988年   94篇
  1987年   88篇
  1986年   68篇
  1985年   54篇
  1984年   44篇
  1983年   49篇
  1982年   21篇
  1981年   16篇
  1980年   13篇
  1979年   42篇
  1978年   16篇
  1977年   29篇
  1974年   15篇
  1973年   17篇
  1969年   16篇
排序方式: 共有4631条查询结果,搜索用时 234 毫秒
81.
Summary When rheumatoid articular cartilage samples were incubated with normal peripheral blood monocytes and cultured synovial cells in the presence of recombinant human interleukin-1 (IL-1) in vitro, large numbers of monocytes were seen to be attached to the articular surface. Significant numbers of monocytes invaded the cartilage tissue when the rheumatoid cartilage samples were pre-incubated with 10 U/ml of IL-1. Considerable numbers of monocytes were also attached to normal cartilage when these were pre-incubated with IL-1. It is of interest that recombinant human gamma interferon (-IFN) did not enhance monocyte attachment. However, there was a significantly greater attachment of monocytes to rheumatoid than to normal cartilage. When normal cartilage was exposed to collagenase and then incubated with monocytes or synovial cells in the presence of 10 U/ml of IL-1, large numbers of cells were attached to the natural cartilage surface but not to the cut surface. These phenomena were much more intense when the rheumatoid cartilage was pre-incubated with collagenase. These results indicate that increased levels of IL-1 in the rheumatoid joint may play an important role in joint destruction by stimulation of pannus formation by inducing synovial cell attachment to the articular surface.  相似文献   
82.
BACKGROUND: Ketotic hypoglycemia is the most common cause of recurrent hypoglycemia in early childhood but its etiology is poorly understood. Elimination diets have been used for the prevention or treatment of some allergic diseases; however, these diets entail a risk to the normal nutrition and growth of children. The present study investigated whether elimination diets are related to the occurrence of ketotic hypoglycemia. METHODS: The prevalence of allergy treated with elimination diet therapy was retrospectively investigated in 18 patients with ketotic hypoglycemia seen in Yamaguchi University Hospital between January 1995 and September 1999. Data were gathered by reviewing the patients' medical charts. RESULTS: Ten (55.6%) of 18 patients with ketotic hypoglycemia had allergic diseases. Six (60%) of the patients had been treated with strict elimination diets and the others were on incomplete elimination diets for the prevention of allergy. The ketotic hypoglycemia patients with allergic diseases had experienced fewer pre-existing infectious diseases than those without allergic diseases. CONCLUSIONS: Patients with allergic diseases treated with elimination diets have a relatively high tendency towards developing ketotic hypoglycemia. They might have a lower capacity to tolerate fasting due to their excessive avoidance of many foods, even during periods when they are not undergoing strict elimination diets.  相似文献   
83.
84.
85.
Objective To investigate the relation between placental embolisation and the diastolic notch in the uterine artery flow velocity waveform of pregnant ewes under general anaesthesia.
Methods Seven pregnant ewes at a gestation 16 to 17 weeks were anaesthesized and micro beads of gelfoam were injected into the uterine artery; changes in the uterine circulation were assessed by Doppler velocimetry.
Results Gelfoam embolisation reduced uterine blood flow in a dose-dependent manner, from a mean (95% CI) of 568 mL/min (495–641) to 159 mL/min (131–187) after the injection of 30 mg of gelfoam, and increased the uterine vascular resistance from 135 mmHg mine L−1 (103–167) to 498 mmHg mino L−1 (422–574). A diastolic notch in uterine artery flow velocity waveform was observed after 20 mg to 25 mg of gelfoam in two ewes and after injection of 30 mg of gelfoam in all seven animals. Injection of 30 mg of gelfoam increased the pulsatility index to 2–4 (1.9–2.9) from 0.6 (0.5–0.7). The mean uterine vascular resistance at the time of the appearance of a diastolic notch was 414 mmHg mine L−1 (377–451).
Conclusion These findings suggest that an elevated pulsatility index and the presence of a diastolic notch in the uterine artery flow velocity waveform are indicators of increased uterine vascular resistance and impaired uterine circulation.  相似文献   
86.
BACKGROUND: The authors clarified the clinical significance of the measurement of serum concentrations of specific IgE antibodies to staphylococcal enterotoxin (SE) A- and SEB in atopic dermatitis (AD). METHODS: The serum concentrations of SEA- and SEB-specific IgE antibodies in 140 pediatric patients with AD were measured with an immuno CAP -radioallergosorbent test system (RAST). To check the cross-reaction of specific IgE antibodies to SEA/SEB and other allergens, the CAP RAST fluorescent enzyme immunoassay inhibition test was performed. RESULTS: Forty-seven patients (33.6%) tested positive for either SEA- or SEB-specific IgE antibodies. School children showed higher positive rates of SEA/SEB-specific IgE antibodies than infants or young children. The patients with severe AD and those with exacerbation of symptoms in summer, had higher positive rates of SEA/SEB-specific IgE antibodies than patients with mild AD or those with exacerbation in winter. In addition, the positive rates of specific IgE antibodies to both dog-dander and cat-dander were higher in patients with positive SEA/SEB-specific IgE antibodies than in patients with negative ones. No cross-reactions occurred among specific IgE antibodies to SEA/SEB and dog/cat dander with one patient's serum, which had positive IgE-specific antibodies against cat/dog dander and SEA/SEB. The positive rate of SEA/SEB-specific IgE antibodies in the patients with dogs and/or cats as pets was 48.4%, which was higher than in those with no pets. CONCLUSIONS: Atopic dermatitis patients who exhibit high positive rates of SEA/SEB-specific IgE antibodies were found to be school children, severe cases, cases with high serum concentrations of total IgE, cases with exacerbation in summer, and cases with dogs and/or cats as pets. The measurement of serum concentrations of specific IgE antibodies to SEA and SEB, thus has some value for evaluating AD patients.  相似文献   
87.
88.
89.
90.
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