全文获取类型
收费全文 | 1148篇 |
免费 | 82篇 |
国内免费 | 19篇 |
专业分类
儿科学 | 36篇 |
妇产科学 | 98篇 |
基础医学 | 98篇 |
口腔科学 | 12篇 |
临床医学 | 77篇 |
内科学 | 408篇 |
皮肤病学 | 33篇 |
神经病学 | 24篇 |
特种医学 | 115篇 |
外科学 | 101篇 |
综合类 | 17篇 |
预防医学 | 25篇 |
眼科学 | 10篇 |
药学 | 46篇 |
中国医学 | 2篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 5篇 |
2022年 | 2篇 |
2021年 | 22篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 25篇 |
2017年 | 14篇 |
2016年 | 15篇 |
2015年 | 21篇 |
2014年 | 25篇 |
2013年 | 53篇 |
2012年 | 51篇 |
2011年 | 54篇 |
2010年 | 45篇 |
2009年 | 36篇 |
2008年 | 50篇 |
2007年 | 74篇 |
2006年 | 36篇 |
2005年 | 49篇 |
2004年 | 50篇 |
2003年 | 52篇 |
2002年 | 56篇 |
2001年 | 44篇 |
2000年 | 34篇 |
1999年 | 37篇 |
1998年 | 39篇 |
1997年 | 46篇 |
1996年 | 32篇 |
1995年 | 23篇 |
1994年 | 29篇 |
1993年 | 19篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 22篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1968年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有1249条查询结果,搜索用时 15 毫秒
1.
The human visual system is amenable to a number of adaptive processes; one such process, or collection of processes, is the adaptation to blur. Blur adaptation can be observed as an improvement in vision under degraded conditions, and these changes occur relatively rapidly following exposure to blur. The potential important future directions of this research area and the clinical implications of blur adaptation are discussed. 相似文献
2.
3.
Reflux is a common cause of chronic cough. Surveys of patients with chronic cough point to a high association with gastroesophageal disease. Because of our bipedalism and speech, humans are prone to both reflux and aspiration. Whether the reflux of stomach contents into the esophagus alone is sufficient to cause cough or whether reflux into the upper airway is required is unknown. In 50 consecutive patients with chronic cough, symptoms of laryngopharangeal reflux (LPR) paralleled those of gastroesophageal reflux, suggesting no unique syndrome of LPR but that it is part of the protean manifestations of reflux disease.
相似文献4.
Y Pean B Hacquard L Berardi-Grassias A Boisivon J Bejot A Eme M P Le Pennec J Morice M Rouchon J Gertner 《Pathologie-biologie》1991,39(5):486-488
Susceptibility to beta-lactam antibiotics of strains of Enterobacteriaceae consecutively isolated in nine general hospitals during a period of 2 months (march and april) has been studied by the disk-agar diffusion method. The separation between susceptible and resistant strains was based on the measure of the inhibition zones centered by 2 disks: cephalothin and ticarcillin. Enterobacteriaceae were divided in 2 groups: strains isolated during the first 48 h of hospitalisation or isolated after. Fifty one per cent of the strains were isolated during the first 48 h: they did not belong to the residential flora of these hospitals. Klebsiella, Proteus indole positive, Providencia, Enterobacter, Serratia were more frequently isolated after 48 h of hospitalisation. Susceptible strains of Klebsiella, Proteus indole positive, Providencia, Serratia were more rarely isolated after 48 h of hospitalisation. E. coli whatever the duration of hospitalisation, is the less frequent susceptible bacterium. 相似文献
5.
Hausegger KA; Cragg AH; Lammer J; Lafer M; Fluckiger F; Klein GE; Sternthal MH; Pilger E 《Radiology》1994,190(1):199
6.
Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients 总被引:1,自引:1,他引:0
al-Wakeel JS; Mitwalli AH; Huraib S; al-Mohaya S; Abu-Aisha H; Chaudhary AR; al-Majed SA; Memon N 《Nephrology, dialysis, transplantation》1997,12(7):1420-1424
High serum fluoride (F-) in patients with chronic renal failure (CRF) and
end-stage renal disease (ESRD) is associated with risk of renal
osteodystrophy and other bone changes. This study was done to determine F-
in normal healthy controls and patients with ESRD on haemodialysis (HD) or
peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females)
and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in
the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l)
of F- content in drinking water. Control subjects showed a mean serum F-
concentration of 1.08 +/- 0.350 microM/l. Males in control group showed
slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than
females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F-
concentration did not correlate significantly with age and sex among
control subjects, whereas such correlation was observed in patients with
ESRD on dialysis. Mean serum F- concentration was significantly higher in
patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal
controls. When grouped according to sex, the mean serum F- concentration in
males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than
females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped
according to age, it was observed that F- concentration was significantly
higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with
age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated
with age and sex, being higher in males and above 20 years. Despite
appreciable clearance of F- (39-90%) across the peritoneum, patients on
CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs
2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their
serum F- concentration above 3.0 microM/l, posing the risk of renal
osteodystrophy.
相似文献
7.
8.
Focal liver lesions: characterization with triphasic spiral CT 总被引:15,自引:1,他引:14
9.
Hepatitis C virus (HCV) genotypes in the Caribbean island of Martinique: evidence for a large radiation of HCV-2 and for a recent introduction from Europe of HCV-4 下载免费PDF全文
Martial J Morice Y Abel S Cabié A Rat C Lombard F Edouard A Pierre-Louis S Garsaud P Béra O Chout R Gordien E Deny P Césaire R 《Journal of clinical microbiology》2004,42(2):784-791
Molecular epidemiological studies of hepatitis C virus (HCV) in the Caribbean may help to specify the origin and spread of HCV infection. Indeed, the Caribbean population is intermixed from European and African origins and geographically close to the American continent. We characterized HCV genotypes in the Caribbean island of Martinique. HCV genotypes were analyzed by sequencing or reverse hybridization in the 5' noncoding region (5'NC) in 250 HCV-monoinfected and 85 HCV-human immunodeficiency virus (HIV)-coinfected patients. In addition, sequencing in the nonstructural 5B (NS5B) gene was required to determine the subtype or to perform phylogenetic analysis in selected samples. Genotypes 1 to 6 were found, respectively, in 84.4, 6.8, 5.2, 2.8, 0.4, and 0.4% of 250 HCV-monoinfected patients and in 71.7, 7.1, 15.3, 5.9, 0, and 0% of 85 HCV-HIV-coinfected patients. HCV-1b was found in 66.4% of the HCV-monoinfected patients and was associated with blood transfusion, whereas HCV-1a was detected in 41.2% of the HCV-HIV-coinfected patients and was associated with intravenous drug use (IVDU). The HCV-3 strains belonged to subtype 3a and were linked to IVDU. Phylogenetic analyses were focused on HCV-2 and HCV-4, which are common in Africa. Two opposite patterns were evidenced. NS5B sequences from 19 HCV-2 isolates were affiliated with many different subtypes described either in Europe or in West Africa, suggesting an ancient radiation. In contrast, seven of the nine HCV-4 NS5B sequences ranged within HCV-4a and HCV-4d clusters spreading in continental France by the IVDU route. Epidemiological data demonstrate the recent introduction of HCV-4a and -4d subtypes into the Caribbean. 相似文献
10.
Metabolic adaptation of the chick embryo to chronic hypoxia 总被引:1,自引:0,他引:1