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   40742篇
  免费   2957篇
  国内免费   221篇
耳鼻咽喉   564篇
儿科学   893篇
妇产科学   622篇
基础医学   4294篇
口腔科学   7521篇
临床医学   2511篇
内科学   8976篇
皮肤病学   566篇
神经病学   2924篇
特种医学   1601篇
外科学   5879篇
综合类   127篇
一般理论   10篇
预防医学   1518篇
眼科学   590篇
药学   2189篇
中国医学   70篇
肿瘤学   3065篇
  2023年   579篇
  2022年   481篇
  2021年   1044篇
  2020年   659篇
  2019年   814篇
  2018年   1260篇
  2017年   993篇
  2016年   1194篇
  2015年   1347篇
  2014年   1672篇
  2013年   1896篇
  2012年   2664篇
  2011年   2650篇
  2010年   1820篇
  2009年   1785篇
  2008年   2352篇
  2007年   2299篇
  2006年   2239篇
  2005年   2161篇
  2004年   1913篇
  2003年   1795篇
  2002年   1778篇
  2001年   651篇
  2000年   570篇
  1999年   610篇
  1998年   556篇
  1997年   461篇
  1996年   446篇
  1995年   397篇
  1994年   363篇
  1993年   306篇
  1992年   416篇
  1991年   312篇
  1990年   350篇
  1989年   282篇
  1988年   308篇
  1987年   270篇
  1986年   225篇
  1985年   212篇
  1984年   218篇
  1983年   176篇
  1982年   154篇
  1981年   121篇
  1980年   85篇
  1979年   112篇
  1978年   104篇
  1977年   69篇
  1976年   75篇
  1973年   65篇
  1972年   75篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
91.
92.
93.
While serum magnesium (Mg) level is increased in patients with end-stage renal disease (ESRD), it is decreased in renal transplant recipients (TR) receiving ciclosporin. This study was performed to examine the cation metabolism of red blood cells (RBC) in these patients. Intracellular free Mg was measured with 31P-nuclear magnetic resonance spectrometry, and ouabain-sensitive sodium (Na) efflux rate (Eos) was measured from the increase in RBC-Na concentration when RBC were incubated in the presence of ouabain. The ouabain-sensitive Na efflux rate constant (ERCos) was obtained by dividing Eos by RBC-Na concentration. RBC free Mg and ERCos were significantly higher in the TR group than in the ESRD group. There was a significant correlation between RBC free Mg and ERCos (r = 0.474, p less than 0.01). These results support the views that the regulation mechanism for intracellular free Mg is different from that for extracellular Mg in patients with renal disease, and intracellular free Mg modulates Na pump activity of RBC.  相似文献   
94.
Little is known about oral health care behaviors of community-dwelling, cognitively impaired elderly (CIE) persons. Few studies have been conducted regarding the actual provision of oral care for CIE persons or the attitudes and concerns about oral health among their caregivers. The CIE person's ability to perform self-care decreases over time, and the role of the caregiver in daily oral care becomes increasingly important. The purpose of this pilot study was to explore the attitudes toward oral health and identify related concerns among caregivers who care for community-dwelling CIE persons. Caregivers were surveyed by means of a self-administered, mailed questionnaire. To maintain confidentiality, an intermediary was used for recruitment and data collection. Overall, 148 caregivers were invited by an intermediary to participate in the survey; only 21 (14%) consented to participate and returned the questionnaire. This paper discusses some of the numerous methodological challenges identified when an attempt was made to survey caregivers' attitudes toward and barriers to providing oral care for a dependent CIE.  相似文献   
95.
96.
The effect of reflux of the duodenal contents on the development of gastric stump carcinoma without carcinogen in rats was studied. At the first experiment, seventy male Wistar rats were subjected to gastrojejunostomy for the diversion of duodenal contents into the resected stomach through the afferent and the efferent loops. The incidence of adenocarcinoma in the afferent anastomosis were 0/8 (0%) at the 10th week, 3/16 (18.8%) at the 20th week and 7/20 (35%) at the 40th week, so the incidence was apt to rise in parallel to the time. In the second experiment, ninety rats were divided into 4 groups: Group I received the same operation as the first experiment, group II received the operation with Braun's anastomosis, group III received the operation for reflux of bile alone to the remnant stomach, and group IV received the operation for reflux of pancreatic juice alone. Animals surviving after surgery were sacrificed at the 40th week. The incidence were 33.3% in group I, 0% in group II, 0% in group III, and 8.3% in group IV, respectively. These findings suggest that reflux of duodenal contents (both bile and pancreatic juice) is an important factor in the gastric stump carcinogenesis.  相似文献   
97.
98.
The effects of alminoprofen, a nonsteroidal anti-inflammatory agent, on the experimental animal models of allergic reactions were examined and compared with those of ibuprofen. Alminoprofen at 30 mg/kg given intraduodenally significantly suppressed passive anaphylactic bronchoconstrictions, while ibuprofen did not at the same doses. In vitro studies revealed that alminoprofen, in contrast to ibuprofen, exerted an inhibitory effect on arachidonate 5-lipoxygenase activity which initiates the bio-synthesis of leukotrienes. Alminoprofen inhibited arachidonic acid-induced ear edema in mice and homologous passive cutaneous anaphylaxis in rats at high doses, while ibuprofen did not at the high doses. From its characteristic feature of inhibitory effects on 5-lipoxygenase activity and the experimental model of type I allergic reaction, it is suggested that alminoprofen is a new type of nonsteroidal anti-inflammatory agent.  相似文献   
99.
There have been few reports of relative rates of provision of dental health services in rural and urban settings, a comparative measure of access to care in these populations. One part of a statewide survey of active North Carolina general dentists (n=959, response rate=47%) was designed to quantify provision of prosthetic services. To determine contrasting rural and urban rates, responses were analyzed according to dentists'self-report of practice city size using analysis of covariance with percent of insured patients in the practice as the covariate. Mean per-patient-visit rates for crowns, fixed partial dentures, removable partial dentures, and extractions, as well as the distributions of treatment following tooth extraction, differed by city size, with practitioners in the smallest cities reporting treatment distributions reflecting more frequent loss of teeth and less frequent replacement. These differences in patterns of prosthetic care echo the limited existing information describing oral health status, provider supply, and receipt of care, all of which suggest that differential levels of access to care exist and lead to differences in oral health outcomes.  相似文献   
100.
Tropical pyomyositis is an infection of muscles mainly presenting in black people, occurring in the trunk and limbs. At Hoima Hospital, Uganda, 58 patients (30 men and 28 women) with a mean age of 21 years have been investigated by ultrasound; a total of 81 lesions were present. Two different characteristic images were found; abscess was present in 65 cases while 16 patients showed a diffuse infiltration among the muscular fibers. These two different images correspond to the two stages of histologic and clinical progression described by other authors. Ultrasound is useful to demonstrate the progression of pyomyositis and to determine when and where to drain any abscess.  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