全文获取类型
收费全文 | 454篇 |
免费 | 36篇 |
国内免费 | 19篇 |
专业分类
儿科学 | 35篇 |
妇产科学 | 11篇 |
基础医学 | 60篇 |
口腔科学 | 15篇 |
临床医学 | 50篇 |
内科学 | 75篇 |
皮肤病学 | 13篇 |
神经病学 | 12篇 |
特种医学 | 112篇 |
外科学 | 37篇 |
综合类 | 12篇 |
预防医学 | 19篇 |
眼科学 | 9篇 |
药学 | 25篇 |
中国医学 | 3篇 |
肿瘤学 | 21篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 12篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 13篇 |
2007年 | 18篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 11篇 |
1998年 | 31篇 |
1997年 | 39篇 |
1996年 | 29篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 14篇 |
1989年 | 22篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 12篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有509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.
Hausegger KA; Cragg AH; Lammer J; Lafer M; Fluckiger F; Klein GE; Sternthal MH; Pilger E 《Radiology》1994,190(1):199
4.
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
5.
6.
Focal liver lesions: characterization with triphasic spiral CT 总被引:15,自引:1,他引:14
7.
Metabolic adaptation of the chick embryo to chronic hypoxia 总被引:1,自引:0,他引:1
8.
The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry 总被引:8,自引:1,他引:8
Nistico L; Buzzetti R; Pritchard LE; Van der Auwera B; Giovannini C; Bosi E; Larrad MT; Rios MS; Chow CC; Cockram CS; Jacobs K; Mijovic C; Bain SC; Barnett AH; Vandewalle CL; Schuit F; Gorus FK; Tosi R; Pozzilli P; Todd JA 《Human molecular genetics》1996,5(7):1075-1080
Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus
is determined by a combination of environmental and genetic factors, which
include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin
gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2
cannot explain the clustering of type 1 diabetes in families, and a role
for other genes is inferred. In the present report we describe linkage and
association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte
associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong
candidate gene for T cell- mediated autoimmune disease because it encodes a
T cell receptor that mediates T cell apoptosis and is a vital negative
regulator of T cell activation. In addition, we provide supporting evidence
that CTLA-4 is associated with susceptibility to Graves' disease, another
organ- specific autoimmune disease.
相似文献
9.
M.C. Nobbs D. Chan-Lam R.T. Howell Clare Kitchen J.A. Copplestone 《Cancer Genetics and Cytogenetics》1993,70(2):144-145
A patient with ANLL FAB subtype M1 was found to possess a t(16;21)(p11;q22) and trisomy 10. The 16;21 translocation has been reported in 12 other cases of ANLL, of various subtypes, and its relationship to the disease profile is discussed. 相似文献
10.
The purpose of this study was to compare the power and strength changes, of the quadriceps femoris muscle group, following 6 weeks of training. Twenty-seven moderately trained, female subjects were placed into three equated groups: electrical stimulation plus isokinetic exercise (ES + IE), isokinetic exercise (IE), and electrical stimulation (ES). A CybexQ I1 isokinetic dynamometer was used for testing the quadriceps ' power and strength output at the velocities of 0, 30, 100, and 180 O/ sec. The ES + IE and ES groups received faradic stimulation (progressive from 10- 20 mA) from a Multitone Multifaradic Unit (model F283, Multitone Electric Co., London, England). In addition, the ES + IE group performed isokinetic contractions concurrently with the faradic stimulation. Thigh circumference (TC) and time to peak tension (TPT) were also calculated during the pre-, mid-, and post-tests. Results indicated that a significant power increment was evident between the pre- and posttests and the pre- and mid-tests for the combined groups (p < 0.05). However, there were no significant power increases between the three separate groups at the four velocities. Significant power differences (P c 0.05) for the combined groups between the pre- and post-tests and the pre- and mid-tests at the isokinetic velocities of 30 and OO/sec were also identified. TPT and TC did not change significantly for any group over the 6-week training period. This study indicated that the combined effects of ES + IE, IE, and ES are potentially effective means of improving power and strength; however, data did not reveal one method of training as being significantly superior to another. J Orthop Sports Phys Ther 1986;8(5):260-268. 相似文献