全文获取类型
收费全文 | 1031篇 |
免费 | 71篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 84篇 |
妇产科学 | 22篇 |
基础医学 | 96篇 |
口腔科学 | 12篇 |
临床医学 | 162篇 |
内科学 | 148篇 |
皮肤病学 | 14篇 |
神经病学 | 43篇 |
特种医学 | 132篇 |
外科学 | 145篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 107篇 |
眼科学 | 26篇 |
药学 | 37篇 |
中国医学 | 2篇 |
肿瘤学 | 66篇 |
出版年
2023年 | 9篇 |
2021年 | 5篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 19篇 |
2014年 | 29篇 |
2013年 | 40篇 |
2012年 | 40篇 |
2011年 | 36篇 |
2010年 | 33篇 |
2009年 | 36篇 |
2008年 | 41篇 |
2007年 | 39篇 |
2006年 | 40篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 14篇 |
2002年 | 32篇 |
2001年 | 16篇 |
2000年 | 18篇 |
1999年 | 27篇 |
1998年 | 35篇 |
1997年 | 43篇 |
1996年 | 36篇 |
1995年 | 30篇 |
1994年 | 30篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 18篇 |
1990年 | 46篇 |
1989年 | 39篇 |
1988年 | 23篇 |
1987年 | 27篇 |
1986年 | 14篇 |
1985年 | 23篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 12篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1973年 | 13篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有1121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.
4.
O P Jakobsson B Pontén 《Nordisk plastikkirurgisk forening [and] Nordisk klubb for handkirurgi》1990,24(2):149-155
The details of two consecutive groups of cleft palate patients treated with one- or two-stage palate repair are presented. The total number of patients is 237, with 128 operated in one stage, and 109 operated in two stages. In the two-stage group, the frequency of 'unintended' palatal fistulas decreased by 80%, and the use of blood transfusions was greatly reduced, but total operation time and hospital stay were longer. The results in terms of speech quality, facial growth and dental occlusion, will be reported on separately. 相似文献
5.
6.
P. Jakobsson L. Jorfeldtt H. von Schenck 《Clinical physiology and functional imaging》1995,15(4):319-329
Summary. In order to investigate fat metabolism and the regulation of lipolysis and blood fuel metabolites by insulin, nine patients with chronic obstructive pulmonary disease (COPD) with chronic hypoxaemia and seven healthy control subjects of similar age were investigated by determination of the turnover rate of free fatty acids (TOR), using 1-14C-oleic acid as a tracer, and arterial concentrations of FFA, glycerol and 3-hydroxybutyrate. The measurements were performed in the basal state and during insulin and glucose infusion, aiming at euglycaemia at insulin levels of 50 and 100 mU l-1. The subjects' ages were 64±2.7 and 66±1.1 (mean±SEM) years in the COPD and control groups, respectively. TOR was 0.73±0.06 and 0.52±0.02 mmol min-1 (P<0.05) in the basal state, 0.33±0.04 and 0.30±0.02 at an insulin level of 50 mU I-1 and 0.32±0.08 and 0.24±0.02 at an insulin level of 100 mU I-1, in the COPD and control groups, respectively. Arterial FFA concentration was 0.98±0.08 and 0.75±0.06 mmol 1-1 (P<0.05) in the basal state in the COPD and control groups, respectively. During the clamp, the decrease in FFA mirrored that in TOR. The results show that the state of lipolysis is increased in severe COPD patients with chronic hypoxaemia. Furthermore, the results suggest a reduced effect of insulin in lipolysis. 相似文献
7.
Hausegger KA; Cragg AH; Lammer J; Lafer M; Fluckiger F; Klein GE; Sternthal MH; Pilger E 《Radiology》1994,190(1):199
8.
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
9.
Water suppressed proton nuclear magnetic resonance (1H NMR) spectroscopy of human plasma has been described as successful in detection of malignancy. We designed a prospective study to test the hypothesis that in vitro NMR spectroscopy has a high sensitivity for detecting early breast cancer. One hundred and thirty-five women were referred for breast biopsy due to abnormal mammograms. One hundred of these were recruited through a population-based mammography screening project. Sixty-nine of 135 women were found to have breast cancer and their average line width of the methyl and methylene resonance in the plasma were compared to those women who had a benign or normal histopathology in the biopsy and to the line width for 100 healthy subjects from the same population. The mean line width at a half-height of the methyl and methylene resonances of the serum lipoprotein lipids in the NMR spectrum did not differ appreciably between the groups. The line width correlated highly with the serum triglycerides, but correction for the level of triglycerides did not improve the diagnostic accuracy of the line width. Receiver-operating characteristic analysis revealed a sensitivity of 61% and a false positive rate of 43% at the most beneficial cut-off of line width (39.7 Hz). In vitro NMR spectroscopy in our hands was thus not a useful diagnostic tool in patients with early breast cancer. 相似文献
10.
Hilmir Asgeirsson Finnbogi Jakobsson Haukur Hjaltason Helga Jonsdottir Sigurlaug Sveinbjornsdottir 《Movement disorders》2006,21(3):293-298
In Iceland, the crude prevalence for all types of primary dystonia was 37.1/10(5) (confidence interval, 30.4-44.9). Focal dystonia had the highest prevalence (31.2/10(5)), followed by segmental (3.1/10(5)), multifocal (2.4/10(5)) and generalized dystonia (0.3/10(5)). Cervical dystonia was the most common focal dystonia (11.5/10(5)), followed by limb dystonia (8.0/10(5)), laryngeal dystonia (5.9/10(5)), blepharospasm (3.1/10(5)), and oromandibular dystonia (2.8/10(5)). The male:female ratio for all patients was 1:1.9 (P=0.0007), and females outnumbered males in all subtypes except oromandibular dystonia. Mean age of onset for all patients was 42.7 years (range, 3-82 years). This prevalence of primary dystonia is higher than in most reported studies, possibly because of more complete ascertainment but the relative frequencies of dystonia subtypes is similar. 相似文献