全文获取类型
收费全文 | 1734篇 |
免费 | 137篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 36篇 |
妇产科学 | 24篇 |
基础医学 | 264篇 |
口腔科学 | 37篇 |
临床医学 | 188篇 |
内科学 | 347篇 |
皮肤病学 | 40篇 |
神经病学 | 237篇 |
特种医学 | 58篇 |
外科学 | 244篇 |
综合类 | 19篇 |
预防医学 | 79篇 |
眼科学 | 18篇 |
药学 | 127篇 |
中国医学 | 31篇 |
肿瘤学 | 105篇 |
出版年
2023年 | 6篇 |
2022年 | 23篇 |
2021年 | 39篇 |
2020年 | 25篇 |
2019年 | 32篇 |
2018年 | 32篇 |
2017年 | 28篇 |
2016年 | 34篇 |
2015年 | 28篇 |
2014年 | 47篇 |
2013年 | 92篇 |
2012年 | 113篇 |
2011年 | 85篇 |
2010年 | 65篇 |
2009年 | 73篇 |
2008年 | 84篇 |
2007年 | 66篇 |
2006年 | 69篇 |
2005年 | 79篇 |
2004年 | 65篇 |
2003年 | 38篇 |
2002年 | 65篇 |
2001年 | 47篇 |
2000年 | 53篇 |
1999年 | 27篇 |
1998年 | 37篇 |
1997年 | 32篇 |
1996年 | 34篇 |
1995年 | 32篇 |
1994年 | 27篇 |
1993年 | 27篇 |
1992年 | 35篇 |
1991年 | 38篇 |
1990年 | 41篇 |
1989年 | 33篇 |
1988年 | 29篇 |
1987年 | 22篇 |
1986年 | 21篇 |
1985年 | 23篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1979年 | 6篇 |
1977年 | 8篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有1889条查询结果,搜索用时 15 毫秒
1.
2.
The effect of prolonged, 22 h long, intracerebroventricular (i.c.v.) infusion of corticotropin-releasing hormone (CRF) on plasma cortisol, corticosterone and electrolyte concentrations, mean arterial blood pressure (MAP) and heart rate (HR) were investigated in conscious rabbits. During i.c.v. infusion of CRF, 1 and 3 μ/h, at a rate of 17 μl/h, plasma cortisol and corticosterone concentrations rose to the level noted after ACTH stimulation in rabbits. Plasma [Na] did not change, but plasma [K] was reduced and plasma osmolality increased during the infusion of CRF, 3 μ/h. MAP and HR, recorded continuously during i.c.v. infusion of CRF, changed only with the higher dose of CRF: MAP was elevated during the first 5 h of infusion, and then returned to the control level. HR was lower than control at the end of the first hour of infusion and again between 9 and 15 h of infusion. The prolonged rise of CRF concentration in the brain induced a sustained rise in circulating adrenal steroid hormones. MAP did not increase to the level noted after bolus i.c.v. injection of CRF and the rise in MAP was not sustained. 相似文献
3.
神经生长因子对小鼠突触体内Ca^2+水平的调节作用 总被引:4,自引:1,他引:3
观察了多次海马内微注射NGF对小鼠突触体内游离钙水平的影响,并在离体情况下观察NGF对EGTA和CaCl2分别造成突触体内低钙和高钙状态的调节作用。结果如下:(1)在体实验表明,一定剂量的NGF可显著降低老年小鼠海马突触体内游离钙水平(P<005);(2)离体实验表明,当突触体游离钙水平降低时,适当剂量的NGF具有升高游离钙水平的作用;而突触体内游离钙水平升高时,则NGF有降低游离钙水平的作用。提示NGF对游离钙水平的双向调节作用可能是NGF改善老年性记忆衰退的作用机制。 相似文献
4.
Relations between basal ganglia and hippocampus: action of substantia nigra and pallidum 总被引:1,自引:0,他引:1
M Sabatino V La Grutta G Ferraro G La Grutta 《Revue d'électroencéphalographie et de neurophysiologie clinique》1986,16(2):179-190
Several interrelationships exist between basal ganglia and hippocampus. The ventral striatum appears to be involved in the control of the dopaminergic nigro-striatal pathway. The caudate, in turn, seems to influence the hippocampal theta rhythm and to inhibit hippocampal spikes. In the present work the role played by globus pallidus pars interna and substantia nigra pars compacta on hippocampal bioelectrical activity is studied. Injection of sodium penicillin i.v. produces steady interictal spikes in the hippocampus. Substantia nigra stimulation induces regular theta rhythm and inhibits the spikes. Pallidal stimulation, on the contrary, appears to strongly enhance epileptiform activity, proceeding to generalised seizure activity. The results are discussed in the light of a putative feedback loop from basal ganglia to hippocampus, probably underlying co-participation of the two subcortical structures in the control of motor behaviour. 相似文献
5.
R Rising S Alger V Boyce H Seagle R Ferraro A M Fontvieille E Ravussin 《The American journal of clinical nutrition》1992,55(2):343-349
Measuring food intake in a laboratory usually involves limited food choices. An automated food-selection system with two vending machines containing a large variety of foods was used to measure food intake in 10 male volunteers (31 +/- 6 y, 69.2 +/- 7.1 kg, 18 +/- 7% fat, mean +/- SD) on a metabolic ward. The effect of carbohydrate, fat, and protein intakes on 24-h energy expenditure (24EE) and substrate oxidations was measured in a respiratory chamber during day 4 of weight maintenance and day 7 of ad libitum intake. Ad libitum intake resulted in a 7-d overfeeding of 6468 +/- 3824 kJ/d above weight-maintenance requirements, leading to a 2.3 +/- 1.2-kg gain. The 10,975 +/- 3774 kJ excess energy intake on day 7 of ad libitum intake caused a 1205 +/- 920 kJ/d increase in 24EE (delta 24EE = 0.17 x delta intake - 695; r = 0.71, P less than 0.02). Of the excess carbohydrate intake, 74% was oxidized (r = 0.86, P less than 0.001), whereas excess fat intake was not. Carbohydrate and protein stores are regulated whereas excess fat intake is channeled to fat stores. 相似文献
6.
7.
8.
9.
Evaluation of single-dose ciprofloxacin in the eradication of Neisseria meningitidis from nasopharyngeal carriers. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D L Dworzack C C Sanders E A Horowitz J M Allais M Sookpranee W E Sanders Jr F M Ferraro 《Antimicrobial agents and chemotherapy》1988,32(11):1740-1741
The ability of a single oral 750-mg dose of ciprofloxacin to eradicate Neisseria meningitidis from persistent nasopharyngeal carriers was prospectively evaluated in a placebo-controlled, randomized, double-blinded study. Cultures of specimens taken from all 23 ciprofloxacin-dosed subjects 1 day postdose were negative; cultures from 96% of these subjects were negative at 7 and 21 days postdose, including a specimen from a subject colonized with a minocycline-resistant strain. Of 22 placebo recipients, 20 (91%) remained culture positive. Single-dose ciprofloxacin appears efficacious for meningococcal prophylaxis. 相似文献
10.