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   370982篇
  免费   286826篇
  国内免费   44428篇
耳鼻咽喉   3563篇
儿科学   5804篇
妇产科学   3502篇
基础医学   101885篇
口腔科学   4468篇
临床医学   75223篇
内科学   110875篇
皮肤病学   5998篇
神经病学   28068篇
特种医学   13153篇
外国民族医学   86篇
外科学   52850篇
综合类   76317篇
现状与发展   33篇
一般理论   15篇
预防医学   50918篇
眼科学   21210篇
药学   71451篇
  138篇
中国医学   52926篇
肿瘤学   23753篇
  2022年   7759篇
  2021年   9249篇
  2020年   10540篇
  2019年   16851篇
  2018年   17422篇
  2017年   18009篇
  2016年   16292篇
  2015年   18105篇
  2014年   19609篇
  2013年   18972篇
  2012年   22332篇
  2011年   24855篇
  2010年   23911篇
  2009年   30342篇
  2008年   19560篇
  2007年   15756篇
  2006年   15166篇
  2005年   14473篇
  2004年   14392篇
  2003年   13482篇
  2002年   13003篇
  2001年   14234篇
  2000年   9699篇
  1999年   14823篇
  1998年   15274篇
  1997年   15141篇
  1996年   15766篇
  1995年   15888篇
  1994年   15607篇
  1993年   13992篇
  1992年   13497篇
  1991年   12690篇
  1990年   11585篇
  1989年   11355篇
  1988年   10913篇
  1987年   10198篇
  1986年   9692篇
  1985年   8720篇
  1984年   6673篇
  1983年   6638篇
  1982年   7668篇
  1981年   7193篇
  1980年   6835篇
  1979年   6707篇
  1978年   5844篇
  1977年   6146篇
  1976年   5764篇
  1975年   5507篇
  1974年   5076篇
  1973年   4784篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
New recommendations suggesting that maternity care should be increasingly community-based have generated concern regarding the interprofessional cooperation between general practitioners and midwives. In Camden, London, this service was expanded in 1993. Although existing joint antenatal care arrangements between GPs and midwives were not expected to alter significantly, the shift of care from hospital to community midwives, and the expansion of community-led care to women with complications, was expected to have implications for the GPs. A questionnaire-based study asked GPs who provide antenatal care about their role and liaison with other professionals. Most were satisfied with the current arrangements; only a minority felt that their workload, clinical practice, or communication with obstetric teams had altered.  相似文献   
992.
穿心莲乙酯对大鼠心肌缺血再灌注损伤的保护作用   总被引:1,自引:0,他引:1  
本实验观察了穿心莲注射液对大鼠心肌缺血再灌注损伤的影响。结果显示:穿心莲(2.5mg·kg~(-1),iv)可保护缺血再灌注心肌SOD活性(P<0.01),降低MDA含量(P<0.001),明显降低严重心律失常发生率。提示穿心莲注射液对缺血再灌注心脏具有保护作用,其抗脂质过氧化作用可能系其作用机制之一。  相似文献   
993.
994.
995.
A retrospective analysis was conducted to determine the effects of metformin on glycosylated hemoglobin (HbA1c), body weight, and adverse events in an African-American population. Thirty-six patients who were receiving combination therapy with metformin and either a sulfonylurea or insulin were identified from a hospital pharmacy database. Nineteen patients met the criteria for efficacy analysis. The combination of metformin with either a sulfonylurea or insulin resulted in a decrease of the average HbA1c from a baseline of 10.07% to 7.92% (delta = 2.15%). The effect of combination therapy on weight was variable; however, twice as many patients lost weight compared with those who gained weight. Metformin appeared to be well-tolerated, with gastrointestinal symptoms being the most commonly reported adverse events.  相似文献   
996.
997.
Seventy-two patients of chronic obstructive pulmonary disease (COPD) of Qi deficiency syndrome with abnormal immune indices were treated with Yiqi Mianyi Granule (YQMYG) and the efficacy was compared with that of 30 cases treated with Zhenqi fuzheng Granule (ZQFZG) for control. Results showed that the markedly effective rate of symptomatic improvement of Qi deficiency in YQMYG group was 65.3%, the total effective rate 93.1%. 88.6% of the immune indices lower than normal were corrected and 43. 7% of them were normalized, while for indices that were higher than normal the rate were 78.2% and 52.9% respectively. These results suggested that YQMYG could improve symptom of Qi Deficiency markedly, strengthen cellular immunity and regulate immune dysfunction. Its therapeutic efficacy was obviously superior to ZQFZG (P<0.Q5).  相似文献   
998.
The subdivisions of the sacral intermediolateral nucleus (IML) of the cat have been studied by using a double-labeling technique of retrograde Fluoro-gold (FG) and wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) tracing. The parasympathetic preganglionic neurons (PGNs) that were labeled by the FG injected into the pelvic nerve formed a ‘V’-shaped column known as the sacral parasympathetic nucleus (SPN) in the sacral IML. The neurons that were labeled by the WGA-HRP applied to the lateral parabrachial nucleus (PBL) formed an elongated spindle-shaped column extending throughout the IML of the sacral segments. We designated it by the name of sacral visceral sensory nucleus (SVSN). These findings indicate that the sacral IML of the cat contain two distinct subdivisions, SPN and SVSN.  相似文献   
999.
During the last decade, kala-azar, which used to be a sporadic disease, became endemic in parts of East-Azerbaijan province in north-west Iran. Many of the 1051 cases observed between 1985 and 1990 were in the district of Meshkin-Shahr (800 cases). The diagnosis was based on symptoms and signs of the disease plus a positive serological test (indirect immunofluorescence assay or direct agglutination test) and, in some cases, the finding of parasites in bone marrow smears. About 90% of the cases were children under 5 years of age. The disease incidence in 1990 was almost ten times that in 1985. New cases are diagnosed throughout the year, but mostly from January till April. Cases were treated with meglumine antimoniate with very satisfactory results; deaths were few among the treated children.  相似文献   
1000.
Respiratory muscle function in cystic fibrosis.   总被引:1,自引:0,他引:1       下载免费PDF全文
A Mier  A Redington  C Brophy  M Hodson    M Green 《Thorax》1990,45(10):750-752
Maximal static expiratory and inspiratory mouth pressures (PEmax and PImax) and quadriceps femoris muscle strength were measured in 25 patients aged 16-28 years with cystic fibrosis (mean FEV1 46% predicted). Mean (SD) PEmax was 64% (18%) predicted (below 75% predicted in 16 of the 25 patients), and PImax was 64% (24%) predicted (below 75% predicted in 14 patients). Quadriceps muscle strength was 68% (20%) predicted (below 75% predicted in 17 patients). The relatively small reduction in respiratory muscle strength in these patients was unlikely to have contributed appreciably to their respiratory problems.  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