全文获取类型
收费全文 | 13121篇 |
免费 | 1133篇 |
国内免费 | 175篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 442篇 |
妇产科学 | 287篇 |
基础医学 | 1069篇 |
口腔科学 | 159篇 |
临床医学 | 2193篇 |
内科学 | 2678篇 |
皮肤病学 | 171篇 |
神经病学 | 1091篇 |
特种医学 | 375篇 |
外科学 | 2479篇 |
综合类 | 430篇 |
一般理论 | 5篇 |
预防医学 | 1282篇 |
眼科学 | 393篇 |
药学 | 520篇 |
中国医学 | 5篇 |
肿瘤学 | 763篇 |
出版年
2023年 | 167篇 |
2022年 | 105篇 |
2021年 | 258篇 |
2020年 | 220篇 |
2019年 | 235篇 |
2018年 | 353篇 |
2017年 | 326篇 |
2016年 | 349篇 |
2015年 | 340篇 |
2014年 | 543篇 |
2013年 | 689篇 |
2012年 | 658篇 |
2011年 | 785篇 |
2010年 | 535篇 |
2009年 | 611篇 |
2008年 | 707篇 |
2007年 | 619篇 |
2006年 | 612篇 |
2005年 | 549篇 |
2004年 | 491篇 |
2003年 | 421篇 |
2002年 | 402篇 |
2001年 | 212篇 |
2000年 | 154篇 |
1999年 | 225篇 |
1998年 | 251篇 |
1997年 | 257篇 |
1996年 | 349篇 |
1995年 | 300篇 |
1994年 | 224篇 |
1993年 | 131篇 |
1992年 | 168篇 |
1991年 | 167篇 |
1990年 | 98篇 |
1989年 | 158篇 |
1988年 | 127篇 |
1987年 | 97篇 |
1986年 | 116篇 |
1985年 | 106篇 |
1984年 | 111篇 |
1983年 | 87篇 |
1982年 | 77篇 |
1981年 | 72篇 |
1980年 | 90篇 |
1978年 | 64篇 |
1977年 | 49篇 |
1976年 | 52篇 |
1975年 | 52篇 |
1964年 | 51篇 |
1963年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
7.
Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery 总被引:5,自引:0,他引:5
Arthur M. Carlin M.D. D. Sudhaker Rao MB B.S. F.A.C.P. F.A.C.E. Ali M. Meslemani M.D. Jeffrey A. Genaw M.D. Nayana J. Parikh Shiri Levy M.D. Arti Bhan M.D. Gary B. Talpos M.D. 《Surgery for obesity and related diseases》2006,2(2):696-103
BACKGROUND: Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery. METHODS: We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D. RESULTS: Mean patient age was 43 +/- 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level 相似文献
8.
We have previously reported the time trends, design and interventions in randomised controlled trials (RCTs) in cystic fibrosis (CF) from 1961 through 1997 [Cheng K, Smyth RL, Motley J, O'Hea U, Ashby D, Randomised controlled trials in cystic fibrosis (1966-1997) categorized by time, design, and intervention. Pediatr Pulmonol 2000, 29:1-7.]. We maintain an ongoing register of all RCTs and controlled clinical trials (CCTs) in CF and have noted that in the five years since 1997 there has been a 48% increase in published trials. We aimed to assess whether this increase has been associated with an improvement in design quality. All RCTs and CCTs from 1961-2002 were assessed. Two epochs were then compared, 1961-1997 and 1998-2002. For each trial we recorded the design, participant numbers and the intervention studied. 261 trials in 1998-2002 were compared with 544 trials in 1961-1997. Comparing the two epochs a similar proportion of trials were parallel, double-blind and placebo controlled; also the median number of participants was similar. In the later epoch 25% of trials were multicentre, compared with 11% previously. Whilst this recent increase in clinical trials in CF is welcome, this has not been associated with improvements in quality. The trend for an increasing proportion of trials to be multicentre is encouraging. There are however, still deficiencies in the design of clinical trials in CF. 相似文献
9.
10.
Tracy Brightman Jiang-Hong Ye Elizabeth Ortiz-Jimenez Edward J. Flynn Wen-Hsien Wu Joseph J. McArdle 《Brain research》1995,678(1-2)
While adult mice receiving picrotoxin (PTX) alone responded with clonic and tonic-clonic seizures, this response was greatly suppressed for mice simultaneously injected with 2,3-butanedione monoxime (BDM). For example, 60% and 10% of the mice convulsed when injected (i.p.) with 3.0 mg/kg PTX alone or PTX plus 205 mg/kg of BDM, respectively. In contrast, a non-oxime analogue of BDM, 2,3-butanedione (BTD), did not have this anticonvulsant effect. In order to explore the basis for the anticonvulsant effect of BDM, we recorded GABA-activated currents (IGABA) of frontal cortical as well as ventromedial hypothalamic neurons before, during and after exposure to this oxime. BDM had a biphasic effect on concentrations (100 μM-40 mM) decreased and lower concentrations (0.01 μM–0.001 μM) potentiatedIGABA; these effects of BDM reversed upon washout of the oxime. In contrast, BTD had no effect onIGABA. Finally, when 0.001 μM BDM, 10–30 μM PTX and GABA were co-applied the inhibitory effect of the toxin onIGABA was markedly suppressed. These data suggest that the anticonvulsant effect of oximes involves facilitation of the inhibitory action of GABA. 相似文献