全文获取类型
收费全文 | 499篇 |
免费 | 28篇 |
国内免费 | 19篇 |
专业分类
儿科学 | 39篇 |
妇产科学 | 14篇 |
基础医学 | 47篇 |
口腔科学 | 10篇 |
临床医学 | 58篇 |
内科学 | 102篇 |
皮肤病学 | 19篇 |
神经病学 | 11篇 |
特种医学 | 112篇 |
外科学 | 46篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 25篇 |
眼科学 | 9篇 |
药学 | 14篇 |
中国医学 | 2篇 |
肿瘤学 | 20篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 15篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 18篇 |
2009年 | 27篇 |
2008年 | 11篇 |
2007年 | 21篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2002年 | 4篇 |
2001年 | 7篇 |
1999年 | 15篇 |
1998年 | 34篇 |
1997年 | 39篇 |
1996年 | 29篇 |
1995年 | 19篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 22篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1980年 | 11篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1970年 | 2篇 |
1964年 | 3篇 |
1963年 | 2篇 |
1958年 | 2篇 |
1956年 | 2篇 |
1955年 | 2篇 |
1954年 | 3篇 |
1949年 | 5篇 |
1948年 | 6篇 |
排序方式: 共有546条查询结果,搜索用时 215 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.
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.
BACKGROUND: In the United States melanoma is the only individually reported skin cancer. There are no large state or national registries for nonmelanoma skin cancer. Nevertheless, rare, that is, nonmelanoma, nonepithelial, tumors can also be locally aggressive and metastasize. OBJECTIVES: This study's purpose was to demonstrate that Mohs surgeons can share data to create a rare skin tumor database. This database may serve as a model for a nationwide database. MATERIALS AND METHODS: We retrospectively reviewed the surgery logs of five Mohs surgery practices in the Houston, Texas, area for rare-nonmelanoma, nonepithelial-skin cancers. A total of 42,279 biopsy-proven cancers of the skin treated with Mohs micrographic surgery were reviewed. Tumor data including type, prevalence, year of treatment, and the treating Mohs surgeon(s) were compiled and analyzed. RESULTS: Forty-three types of rare tumors were identified. A total of 317 rare tumors were treated. No practice saw more than 28 rare tumor types. Atypical fibroxanthoma was the rare tumor most often treated. CONCLUSIONS: Colleagues can cooperate to create a database of rare tumors removed by Mohs micrographic surgery. A range of tumors greater than that seen in any single practice is now available for study. This should provide the impetus for a nationwide rare skin tumor database. 相似文献
8.
Focal liver lesions: characterization with triphasic spiral CT 总被引:15,自引:1,他引:14
9.
Metabolic adaptation of the chick embryo to chronic hypoxia 总被引:1,自引:0,他引:1
10.
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