全文获取类型
收费全文 | 3163230篇 |
免费 | 248171篇 |
国内免费 | 5660篇 |
专业分类
耳鼻咽喉 | 45816篇 |
儿科学 | 101684篇 |
妇产科学 | 85286篇 |
基础医学 | 446818篇 |
口腔科学 | 90052篇 |
临床医学 | 287641篇 |
内科学 | 615673篇 |
皮肤病学 | 65916篇 |
神经病学 | 261335篇 |
特种医学 | 125848篇 |
外国民族医学 | 1311篇 |
外科学 | 477375篇 |
综合类 | 74272篇 |
现状与发展 | 2篇 |
一般理论 | 1254篇 |
预防医学 | 253677篇 |
眼科学 | 74190篇 |
药学 | 236608篇 |
6篇 | |
中国医学 | 5952篇 |
肿瘤学 | 166345篇 |
出版年
2018年 | 32631篇 |
2017年 | 24988篇 |
2016年 | 27581篇 |
2015年 | 31155篇 |
2014年 | 44556篇 |
2013年 | 67936篇 |
2012年 | 92214篇 |
2011年 | 97606篇 |
2010年 | 57655篇 |
2009年 | 55073篇 |
2008年 | 92616篇 |
2007年 | 98770篇 |
2006年 | 99417篇 |
2005年 | 96729篇 |
2004年 | 93651篇 |
2003年 | 90615篇 |
2002年 | 89035篇 |
2001年 | 146210篇 |
2000年 | 151415篇 |
1999年 | 128361篇 |
1998年 | 37196篇 |
1997年 | 33721篇 |
1996年 | 33570篇 |
1995年 | 32373篇 |
1994年 | 30339篇 |
1993年 | 28333篇 |
1992年 | 103236篇 |
1991年 | 100321篇 |
1990年 | 96935篇 |
1989年 | 93352篇 |
1988年 | 86450篇 |
1987年 | 85192篇 |
1986年 | 80393篇 |
1985年 | 76926篇 |
1984年 | 58335篇 |
1983年 | 49670篇 |
1982年 | 29892篇 |
1981年 | 26834篇 |
1979年 | 54354篇 |
1978年 | 38104篇 |
1977年 | 32212篇 |
1976年 | 30282篇 |
1975年 | 32186篇 |
1974年 | 39238篇 |
1973年 | 37371篇 |
1972年 | 34859篇 |
1971年 | 32083篇 |
1970年 | 30385篇 |
1969年 | 28089篇 |
1968年 | 25587篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
The amount of endothelial cell loss that occurs to the donor cornea during the trephination process was evaluated in 40 porcine eyes. A vital staining technique (alizarin red S and acid violet 19) was used to quantify the extent of endothelial damage and removal. Two types of corneal punches (Weck and H&I0 were used for trephination. The average amount of endothelial loss from the peripheral cornea was 7.9%, accounting for only a 3% loss of endothelial cells over the total surface area of the corneal button. a comparison of the Weck and H&I corneal punches showed no significant difference (P greater than 0.1) by Student's test for both endothelial cell damage and removal. 相似文献
912.
913.
H Murakami M Togawa S Takahashi N Kasahara J Yamamoto N Matsuura Y Koshiyama Y Ino M Oda 《Arzneimittel-Forschung》1990,40(12):1352-1358
The effects of FUT-187 (6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl)amino]benzoate dimethanesulfonate, CAS 103926-82-5), a novel synthetic protease inhibitor, were examined in experimental rat and canine models of pancreatitis. 1. FUT-187 significantly increased the survival of rats with trypsin- and phospholipase A2-induced pancreatitis in a dose-dependent manner (10-100 mg/kg, p.o.). 2. FUT-187 decreased plasma enzymatic activity reflecting the degree of pancreatitis in rats with ethionine-induced pancreatitis, and showed a tendency to ameliorate histopathological changes in the pancreas (10-100 mg/kg p.o.). 3. FUT-187 (10 mg/kg) produced an obvious improvement of various biochemical parameters of pancreatitis and also reduced histopathological changes in the pancreas in animals with experimental pancreatitis produced by the closed duodenal loop method. In addition, FUT-187 significantly increased the survival of dogs when given by direct administration into the lumen of the closed duodenal loop. The therapeutic effects of FUT-187 in experimental pancreatitis were nearly equal in most instances to those of camostat mesilate. Thus, FUT-187 would appear to be an effective new agent for the treatment of pancreatitis. 相似文献
914.
Kappa-opioid-receptor agonists modulate the renal excretion of water and electrolytes in anaesthetized rats. 总被引:1,自引:0,他引:1 下载免费PDF全文
1. Subcutaneous injection of the kappa-opioid agonists U50,488 (10 mg kg-1) and tifluadom (3.5 mg kg-1) into Inactin-anaesthetized, saline-infused rats was associated with a diuresis, antinatriuresis and antikaliuresis which lasted for up to 2 h. A high (5 mg kg-1), but not low (0.1 mg kg-1), dose of naloxone blocked the renal effects of U50,488. 2. U50,488 administration in anaesthetized, vasopressin-deficient Brattleboro DI rats was associated with an attenuated diuresis, though the antinatriuretic response remained intact. 3. The diuretic action of U50,488 was associated with an increase in glomerular filtration rate while fractional fluid reabsorption remained steady. In contrast, fractional sodium and potassium reabsorption were increased. 4. These data suggest that kappa-opioid agonists alter renal handling of both water and electrolytes. This appears to be mediated by two separate mechanisms: increased fluid loss largely reflects altered glomerular events while the fall in electrolyte excretion results from altered tubular handling. 相似文献
915.
G Durrieu P Valet M Berlan A Villeneuve J L Montastruc 《European journal of pharmacology》1990,182(3):597-601
Treatment of dogs for 21 days with oral levodopa (100 mg b.i.d.) plus benserazide (25 mg b.i.d.) induced a significant increase in the number of platelet alpha 2-adrenoceptors labelled by [3H] yohimbine with no change in Kd. The rise was maximal at the end of the treatment and remained significant during the month following the cessation of treatment. Plasma catecholamine levels did not vary. Competition experiments showed a low affinity of both dopamine and levodopa for platelet alpha 2-adrenoceptors. These results suggest that levodopa treatment regulates alpha 2-adrenoceptor number in dog platelets. 相似文献
916.
J Rochemaure P Lehert J Sauvaget M Robillard A Betbeder-Matibet 《Revue de pneumologie clinique》1988,44(1):43-47
Fifty-six patients with recurrent bronchopulmonary infections associated with chronic bronchitis were randomly allocated to 2 groups, to assess whether treatment with an immunomodulator, Diribiotin CK, could enhance resistance to infection. The double-blind, placebo-controlled prospective trial over a 9 month period showed that this immunomodulator was well tolerated and significantly reduced the rate of respiratory tract infection. The drug also significantly reduced the prescribing of antibiotic medication and the rate of absenteism from work. These effects have been demonstrated in a rigorously designed clinical study. This is the first time that a clear clinical activity has been attributed to an inducer of soluble mediators of immunity. 相似文献
917.
J. Rutenfranz W. Ottmann B. Neidhart W. Brockmann 《International archives of occupational and environmental health》1988,61(1-2):89-93
Summary A typical shiftwork experiment was chosen to prove the validity of an automated procedure for the analysis of free noradrenaline and adrenaline in urine. The method consists of a column switching technique with an adsorption/elution clean-up and a reversed phase high performance liquid chromatography followed by chemical reaction detection based on the trihydroxyindole method. The analysis of variance was performed using a second data set obtained by a semi-automated procedure for which the accuracy had already been confirmed. The analysis of covariance showed that for field studies, as well as for laboratory experiments in which the variances contributed by the experiments themselves are greater than 10% rel., the data sets of the two methods provide the same information.Dedicated to Prof. H. Hartkamp, University of Wuppertal, on the occasion of his 60th birthday 相似文献
918.
The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention. 相似文献
919.
920.
A. Taytard J. F. Tessier J. G. Faugere J. Vergeret P. Freour 《European journal of epidemiology》1988,4(3):326-330
Professional exposure to vegetable dusts affect the respiratory function of the exposed subjects. A previous survey conducted in an industrial flour-mill demonstrated a higher frequency of respiratory symptoms in workers compared to a control group. Ten subjects employed in a work site particularly exposed to dust were studied. Each subject answered a questionnaire and performed on Mondays and Fridays, at the begenning and end of his work shift, a flow volume curve and an isocapnic hyperventilation test. The aerobiology of the professional environment was also measured. We noted: 1) in the flow volume curves: a drop in the FEV1 during the Monday morning shift, a significant difference between the FEV1 (p<0.05) and the MMEFR 25–75 (p<0.05) measured at 6 am on Monday and Friday, and between the MMEFR 25–75 values obtained at 12 noon on Monday and Friday (p<0.05). 2) after isocapnic hyperventilation, a significant drop in the MMEFR 25–75 at 6 am on Monday (p<0.01) and in the FEV1 and MMEFR 25–75 at 12 noon on Mondays (p<0.05), a significant drop in the FEV1 at 1 pm on Monday (p<0.01). 相似文献