全文获取类型
收费全文 | 1109篇 |
免费 | 63篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 86篇 |
妇产科学 | 10篇 |
基础医学 | 101篇 |
口腔科学 | 25篇 |
临床医学 | 137篇 |
内科学 | 265篇 |
皮肤病学 | 19篇 |
神经病学 | 25篇 |
特种医学 | 306篇 |
外科学 | 70篇 |
综合类 | 13篇 |
预防医学 | 31篇 |
眼科学 | 6篇 |
药学 | 27篇 |
肿瘤学 | 61篇 |
出版年
2023年 | 2篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 14篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 25篇 |
2012年 | 12篇 |
2011年 | 17篇 |
2010年 | 34篇 |
2009年 | 28篇 |
2008年 | 14篇 |
2007年 | 36篇 |
2006年 | 20篇 |
2005年 | 25篇 |
2004年 | 24篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 28篇 |
1998年 | 96篇 |
1997年 | 70篇 |
1996年 | 77篇 |
1995年 | 53篇 |
1994年 | 54篇 |
1993年 | 61篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 39篇 |
1988年 | 25篇 |
1987年 | 38篇 |
1986年 | 23篇 |
1985年 | 29篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 22篇 |
1981年 | 23篇 |
1980年 | 28篇 |
1979年 | 6篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 20篇 |
1975年 | 13篇 |
1932年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有1184条查询结果,搜索用时 15 毫秒
1.
Irritable bowel syndrome and health-related quality of life: a population-based study in Calgary, Alberta. 总被引:3,自引:0,他引:3
Feng Xiao Li Scott B Patten Robert J Hilsden Lloyd R Sutherland 《Journal canadien de gastroenterologie》2003,17(4):259-263
BACKGROUND: Little is known about the health-related quality of life (HRQOL) of nonclinical samples of people with irritable bowel syndrome (IBS) in Canada. In a pilot survey, the impact of IBS on HRQOL using a population-based, urban sample was examined. METHODS: A random sample of Calgary residents (18 years of age or older), selected by random digit dialing (n=1521), completed a structured questionnaire including ROME II Criteria and Medical Outcomes Study Short-Form 12-Item Health Survey, version 2 (SF-12v2). The mean scale and summary scores of SF-12v2 for those who did and did not meet ROME II criteria and for those who met ROME II criteria with and without visiting a physician in past three months were determined and compared using multiple regression analyses. RESULTS: Of the 951 households successfully contacted, 590 (62%) were willing to participate, of which 437 (74%) individuals were recruited. One hundred ten IBS cases (81 of which were women) and 327 non-IBS controls (180 of which were women) were identified. All of the eight mean scale scores and the two mean summary scores were significantly lower in people with IBS than in those without, whether or not adjusting for demographics. Forty-four of the 110 IBS cases (40%) sought medical help. Significantly lower mean physical component score and three scale scores (general health, social functioning and role physical) were found in those who sought medical help than in those who did not. CONCLUSIONS: People with IBS experience significant impairment in HRQOL, including both physical and mental well-being. People with IBS who seek medical help report worse physical health than those who do not, but their mental health is no different. 相似文献
2.
3.
4.
5.
6.
7.
8.
Competitive control of the self-renewing T cell repertoire 总被引:1,自引:0,他引:1
We develop a mathematical model for the self-renewing part of the T cell
repertoire. Assuming that self-renewing T cells have to be stimulated by
immunogenic MHC-peptide complexes presented on the surfaces of
antigen-presenting cells, we derive a model of T cell growth in which
competition for MHC-peptide complexes limits T cell clone sizes and
regulates the total number of self-renewing T cells in the animal. We show
that for a sufficient diversity and/or degree of cross-reactivity, the
total T cell number hardly depends upon the diversity of the T cell
repertoire or the diversity of the set of presented peptides. Conversely,
for repertoires of lower diversity and/or cross-reactivity, steady-state
total T cell numbers may be limited by the diversity of the T cells. This
provides a possible explanation for the limited repertoire expansion in
some, but not all, mouse T cell re-constitution experiments. We suggest
that the competitive interactions described by our model underlie the
normal T cells numbers observed in transgenic mice, germ-free mice and
various knockout mice.
相似文献
9.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献
10.
IMPT1, an imprinted gene similar to polyspecific transporter and multi- drug resistance genes 总被引:5,自引:1,他引:5
Dao D; Frank D; Qian N; O'Keefe D; Vosatka RJ; Walsh CP; Tycko B 《Human molecular genetics》1998,7(4):597-608
Human chromosome 11p15.5 and distal mouse chromosome 7 include a
megabase-scale chromosomal domain with multiple genes subject to parental
imprinting. Here we describe mouse and human versions of a novel imprinted
gene, IMPT1 , which lies between IPL and p57 KIP2 and which encodes a
predicted multi-membrane-spanning protein similar to bacterial and
eukaryotic polyspecific metabolite transporter and multi- drug resistance
pumps. Mouse Impt1 and human IMPT1 mRNAs are highly expressed in tissues
with metabolite transport functions, including liver, kidney, intestine,
extra-embryonic membranes and placenta, and there is strongly preferential
expression of the maternal allele in various mouse tissues at fetal stages.
In post-natal tissues there is persistent expression, but the allelic bias
attenuates. An allelic expression bias is also observed in human fetal and
post-natal tissues, but there is significant interindividual variation and
rare somatic allele switching. The fact that Impt1 is relatively repressed
on the paternal allele, together with data from other imprinted genes,
allows a statistical conclusion that the primary effect of human chromosome
11p15.5/mouse distal chromosome 7 imprinting is domain-wide relative
repression of genes on the paternal homolog. Dosage regulation of the
metabolite transporter gene(s) by imprinting might regulate placental and
fetal growth.
相似文献