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   167202篇
  免费   10704篇
  国内免费   1302篇
耳鼻咽喉   2405篇
儿科学   3076篇
妇产科学   3819篇
基础医学   24995篇
口腔科学   3466篇
临床医学   15674篇
内科学   31866篇
皮肤病学   4533篇
神经病学   12429篇
特种医学   8528篇
外科学   22749篇
综合类   2188篇
现状与发展   5篇
一般理论   82篇
预防医学   9895篇
眼科学   4527篇
药学   14190篇
中国医学   1670篇
肿瘤学   13111篇
  2023年   1029篇
  2022年   2901篇
  2021年   5016篇
  2020年   2571篇
  2019年   3770篇
  2018年   4608篇
  2017年   3419篇
  2016年   4441篇
  2015年   5959篇
  2014年   7287篇
  2013年   8780篇
  2012年   13261篇
  2011年   12845篇
  2010年   7590篇
  2009年   6353篇
  2008年   9607篇
  2007年   9437篇
  2006年   8642篇
  2005年   8230篇
  2004年   7305篇
  2003年   6364篇
  2002年   5559篇
  2001年   4428篇
  2000年   4066篇
  1999年   3295篇
  1998年   1330篇
  1997年   1011篇
  1996年   961篇
  1995年   875篇
  1994年   759篇
  1993年   657篇
  1992年   1582篇
  1991年   1577篇
  1990年   1362篇
  1989年   1244篇
  1988年   1161篇
  1987年   1036篇
  1986年   1012篇
  1985年   886篇
  1984年   648篇
  1983年   566篇
  1982年   403篇
  1981年   381篇
  1980年   344篇
  1979年   521篇
  1978年   406篇
  1977年   388篇
  1976年   343篇
  1974年   360篇
  1973年   327篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
Eleven men consumed a basal diet alone and with cellulose (Na-carboxymethylcellulose, locust bean gum, or karaya gum) added at 7.5 g fiber per 1000 calories for 4 wk each. Food, urine, and fecal composites were collected during the last 8 d of each feeding period. Bowel transit time was not significantly affected; however, total dry fecal weight was significantly increased after the refined fibers compared with that after the basal diet. Adding refined fibers to the basal diet did not significantly affect apparent mineral balance of calcium, magnesium, manganese, iron, copper, or zinc, with the exception of a negative mineral balance for manganese with carboxymethylcellulose. Karaya gum had a mean positive balance for all minerals tested. These results indicate that the hypocholesterolemic effect of the fibers that form gels occurs without compromising mineral balance in those subjects consuming Recommended Dietary Allowance levels of the minerals studied.  相似文献   
112.
113.
114.
115.
116.
117.
The effect of acute and subchronic dosing with etodolac on the renal PGE2 and 6-keto-PGF concentrations in the normal rat were studied. Etodolac and other nonsteroidal antiinflammatory drugs (NSAIDs) were administered orally, at equieffective antiinflammatory doses, to normal rats either as a single dose or as seven daily doses. Whole kidney prostaglandin (PG) concentrations were measured. In the acute study, etodolac (3 mg/kg) did not significantly lower the PGE2 levels for up to 4 hr postdosing. In contrast, naproxen (3 mg/kg) and piroxicam (0.5 mg/kg) significantly decreased the PGE2 levels to about 20% and 60% of control, respectively. Similar reductions in 6-keto-PGF concentrations were observed. In the subchronic study, etodolac (3 mg/kg/day) did not lower either PGF2 or 6-keto-PGF concentrations whereas naproxen (3 mg/kg/day), piroxicam (0.5 mg/kg/day), indomethacin (1 mg/kg/day), and aspirin (300 mg/kg/day) significantlydecreased both PGs. In both studies, the effect of etodolac was significantly different from that of the NSAIDs. It is concluded that etodolac possesses only a very weak capacity to lower renal PGs, and therefore is unlikely to cause any renal complications related to PG biosynthesis inhibition.  相似文献   
118.
119.
To assess the magnitude and nature of interpersonal violence resulting in hospitalisation of children and to identify subgroups at risk of repeat hospital admissions, a population-based, retrospective study of all violence hospitalisations in Western Australia for children aged 9 years or less was undertaken, using the 1990–2004 linked data retrieved from the Western Australian Mortality Database and the Hospital Morbidity Data System.
Of the 747 patients aged <10 years incurring 834 hospitalisations for the consequences of violence during the study period, 570 (76%) were less than 4 years of age. A total of 43 deaths from violence were recorded and 74 (9%) patients were admitted for more than one episode of violence. Victims aged 0–4 years from rural (hazard ratio [HR] = 2.72; 95% confidence interval [CI] 1.35, 5.43) and remote parts (HR = 2.79; 95% CI 1.25, 6.25) of the state were at increased risk of a subsequent admission for violence compared with those residing within the metropolitan area. Indigenous children aged 5–9 years were significantly more likely (HR = 3.57; 95% CI 1.14, 11.13) to incur a second hospitalisation for violence than their non-Indigenous counterparts. The identification of young victim subgroups at high risk of repeat hospitalisations is important for developing intervention strategies to reduce the burden of interpersonal violence. Young children aged 0–4 years living in rural and remote locations and Indigenous children aged 5–9 years should be specifically targeted for attention.  相似文献   
120.
The purpose of this study was to investigate whether (18)F-FDG PET/CT is useful for localizing dystonic cervical muscles in patients with idiopathic cervical dystonia (ICD) by comparing disease severity before and disease severity after botulinum toxin (BT) injection into hypermetabolic muscles. METHODS: Six patients with ICD underwent (18)F-FDG PET/CT. Dystonic muscles suitable for BT injection therapy were defined as those showing diffusely increased (18)F-FDG uptake. RESULTS: Hypermetabolic cervical muscles were identified in all 6 patients. In 2 patients who underwent PET/CT both in a supine position and in a sitting position during (18)F-FDG uptake, abnormal hypermetabolic muscles were observed by PET/CT only when patients were in the sitting position with their heads and necks in the adopted abnormal involuntary posture. Symptoms were significantly improved in 4 patients who underwent BT injection therapy guided by PET/CT and who were clinically monitored. CONCLUSION: (18)F-FDG PET/CT is potentially useful for identifying dystonic cervical muscles for BT therapy in patients with ICD.  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