全文获取类型
收费全文 | 902篇 |
免费 | 57篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 47篇 |
妇产科学 | 11篇 |
基础医学 | 89篇 |
口腔科学 | 48篇 |
临床医学 | 78篇 |
内科学 | 192篇 |
皮肤病学 | 8篇 |
神经病学 | 14篇 |
特种医学 | 120篇 |
外国民族医学 | 1篇 |
外科学 | 65篇 |
综合类 | 6篇 |
预防医学 | 50篇 |
眼科学 | 9篇 |
药学 | 195篇 |
肿瘤学 | 49篇 |
出版年
2022年 | 6篇 |
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 7篇 |
2018年 | 21篇 |
2017年 | 12篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 15篇 |
2013年 | 24篇 |
2012年 | 23篇 |
2011年 | 14篇 |
2010年 | 25篇 |
2009年 | 18篇 |
2008年 | 30篇 |
2007年 | 42篇 |
2006年 | 16篇 |
2005年 | 32篇 |
2004年 | 15篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 22篇 |
2000年 | 12篇 |
1999年 | 15篇 |
1998年 | 45篇 |
1997年 | 49篇 |
1996年 | 55篇 |
1995年 | 39篇 |
1994年 | 34篇 |
1993年 | 34篇 |
1992年 | 19篇 |
1991年 | 21篇 |
1990年 | 18篇 |
1989年 | 29篇 |
1988年 | 25篇 |
1987年 | 21篇 |
1986年 | 18篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有986条查询结果,搜索用时 15 毫秒
1.
2.
An anomalous pulmonary vein draining into the subdiaphragmatic inferior vena cava was initially demonstrated on computed tomographic (CT) scans. The diagnosis of scimitar syndrome was confirmed with digital subtraction angiography. In retrospect, the anomalous vein and dextroposition of the heart were shown on chest radiographs. 相似文献
3.
Percutaneous absorption of 2,6-di-tert-butyl-4-nitrophenol (DBNP) in isolated perfused porcine skin.
Alfred O Inman Kenneth R Still Warren W Jederberg Robert L Carpenter Jim E Riviere James D Brooks Nancy A Monteiro-Riviere 《Toxicology in vitro》2003,17(3):289-292
DBNP (2,6-di-tert-butyl-4-nitrophenol) has been reported as a potential contaminant in submarines. This yellow substance forms when lubrication oil mist containing the antioxidant additive 2,6-di-tert-butylphenol passes through an electrostatic precipitator and is nitrated. Percutaneous absorption of 14C-DBNP was assessed in the isolated perfused porcine skin flap (IPPSF). Four treatments were studied (n=4 flaps/treatment): 40.0 microgram/cm(2) in 100% ethanol; 40.0 microgram/cm(2) in 85% ethanol/15% H(2)O; 4.0 microgram/cm(2) in 100% ethanol; and 4.0 microgram/cm(2) in 85% ethanol/15% water. DBNP absorption was minimal across all treatment groups, with the highest absorption detected being only 1.08% applied dose in an aqueous ethanol group. The highest mass of 14C-DBNP absorbed was only 0.5 microgram. The majority of the applied dose remained on the surface of the skin. This suggests that there is minimal dermal exposure of DBNP when exposed topically to skin. 相似文献
4.
D Mahalanabis H Ashraf MM Rahman GJ Fuchs 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(11):1113-1115
One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg−1 ) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea. 相似文献
5.
6.
Elastin point mutations cause an obstructive vascular disease, supravalvular aortic stenosis 总被引:7,自引:2,他引:7
Li DY; Toland AE; Boak BB; Atkinson DL; Ensing GJ; Morris CA; Keating MT 《Human molecular genetics》1997,6(7):1021-1028
Supravalvular aortic stenosis (SVAS) is an inherited obstructive vascular
disease that affects the aorta, carotid, coronary and pulmonary arteries.
Previous molecular genetic data have led to the hypothesis that SVAS
results from mutations in the elastin gene, ELN. In these studies, the
disease phenotype was linked to gross DNA rearrangements (35 and 85 kb
deletions and a translocation) in three SVAS families. However, gross
rearrangements of ELN have not been identified in most cases of autosomal
dominant SVAS. To define the spectrum of ELN mutations responsible for this
disorder, we refined the genomic structure of human ELN and used this
information in mutational analyses. ELN point mutations co-segregate with
the disease in four familial cases and are associated with SVAS in three
sporadic cases. Two of the mutations are nonsense, one is a single base
pair deletion and four are splice site mutations. In one sporadic case, the
mutation arose de novo. These data demonstrate that point mutations of ELN
cause autosomal dominant SVAS.
相似文献
7.
NYVAC: a highly attenuated strain of vaccinia virus. 总被引:33,自引:0,他引:33
J Tartaglia M E Perkus J Taylor E K Norton J C Audonnet W I Cox S W Davis J van der Hoeven B Meignier M Riviere 《Virology》1992,188(1):217-232
A highly attenuated vaccinia virus strain, NYVAC (vP866), was derived from a plaque-cloned isolate of the Copenhagen vaccine strain by the precise deletion of 18 open reading frames (ORFs) from the viral genome. Among the ORFs deleted from NYVAC (vP866) are two genes involved in nucleotide metabolism, the thymidine kinase (ORF J2R) and the large subunit of the ribonucleotide reductase (ORF I4L); the gene encoding the viral hemagglutinin (ORF A56R); the remnant (ORF A26L) of a highly expressed gene responsible for the formation of A-type inclusion bodies; the disrupted gene (ORFs B13R/B14R) normally encoding a serine protease inhibitor; and a block of 12 ORFs bounded by two known viral host range regulatory functions (ORFs C7L through K1L). Within this block a secretory protein (ORF N1L) implicated in viral virulence and a functional complement 4b binding protein (ORF C3L) are encoded. The ORFs were deleted in a manner which prevents the synthesis of undesirable novel gene products. The attenuation characteristics of the derived NYVAC strain were compared in in vitro and in vivo studies with those of the Western Reserve (WR) laboratory strain, the New York City Board of Health vaccine strain (Wyeth), the parental plaque-cloned isolate (VC-2) of the Copenhagen vaccine strain used to derive NYVAC, and the avipox virus canarypox (ALVAC), which is naturally restricted for replication to avian species. The NYVAC strain was demonstrated to be highly attenuated by the following criteria: (a) no detectable induration or ulceration at the site of inoculation on rabbit skin; (b) rapid clearance of infectious virus from the intradermal site of inoculation on rabbit skin; (c) absence of testicular inflammation in nude mice; (d) greatly reduced virulence as demonstrated by the results of intracranial challenge of both 3-week-old or newborn mice; (e) greatly reduced pathogenicity and failure to disseminate in immunodeficient (nude or cyclophosphamide treated) mice; and (f) dramatically reduced ability to replicate on a variety of human tissue culture cells. Despite these highly attenuated characteristics, the NYVAC strain, as a vector, retains the ability to induce strong immune responses to extrinsic antigens. 相似文献
8.
9.
J. Diebold O. Riviere B. Gosselin A. Janin-Mercier A. Canelhas A. Le Tourneau J. Audouin 《Virchows Archiv : an international journal of pathology》1991,419(4):273-280
Summary Three cases of splenic involvement in three different types of generalized mastocytosis (systemic mast cell disease) are reported. The macroscopic, histological and ultrastructural modifications of the spleen are described. Each case exhibited a different morphological pattern. Giemsa staining, fluorescence after acridine orange staining and naphthol ASD chloracetate esterase reaction are shown to be valuable for diagnosis. By comparison, immunohistochemistry seemed not to be very useful, because no specific antigens are expressed. These findings are compared to previously published cases. Their value for the diagnosis and the prognosis are discussed. 相似文献
10.
We studied the relationship between nutritional status and infection due to specific enteropathogens in young children with diarrhoea. Overall, 26% of the children were severely underweight, 27% were severely wasted and 19% were severely stunted. Children with Shigellae and V. cholerae O1 were significantly more severely underweight, wasted and stunted than those with rotavirus diarrhoea ( p < 0:0001). Our results indicate that an effective nutrition programme for young children might have greater impact on diarrhoeal illness caused by Shigella and V. cholerae than by rotavirus diarrhoea. 相似文献