全文获取类型
收费全文 | 2793篇 |
免费 | 247篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 106篇 |
妇产科学 | 28篇 |
基础医学 | 322篇 |
口腔科学 | 162篇 |
临床医学 | 359篇 |
内科学 | 617篇 |
皮肤病学 | 45篇 |
神经病学 | 226篇 |
特种医学 | 286篇 |
外科学 | 269篇 |
综合类 | 62篇 |
预防医学 | 173篇 |
眼科学 | 45篇 |
药学 | 226篇 |
中国医学 | 10篇 |
肿瘤学 | 100篇 |
出版年
2023年 | 15篇 |
2021年 | 34篇 |
2020年 | 29篇 |
2019年 | 35篇 |
2018年 | 52篇 |
2017年 | 32篇 |
2016年 | 39篇 |
2015年 | 52篇 |
2014年 | 66篇 |
2013年 | 86篇 |
2012年 | 104篇 |
2011年 | 92篇 |
2010年 | 93篇 |
2009年 | 98篇 |
2008年 | 96篇 |
2007年 | 107篇 |
2006年 | 102篇 |
2005年 | 95篇 |
2004年 | 85篇 |
2003年 | 101篇 |
2002年 | 82篇 |
2001年 | 85篇 |
2000年 | 72篇 |
1999年 | 74篇 |
1998年 | 72篇 |
1997年 | 72篇 |
1996年 | 76篇 |
1995年 | 68篇 |
1994年 | 64篇 |
1993年 | 68篇 |
1992年 | 52篇 |
1991年 | 63篇 |
1990年 | 49篇 |
1989年 | 89篇 |
1988年 | 65篇 |
1987年 | 65篇 |
1986年 | 70篇 |
1985年 | 57篇 |
1984年 | 49篇 |
1983年 | 39篇 |
1982年 | 31篇 |
1981年 | 33篇 |
1980年 | 27篇 |
1979年 | 29篇 |
1978年 | 24篇 |
1977年 | 27篇 |
1976年 | 20篇 |
1975年 | 22篇 |
1973年 | 17篇 |
1970年 | 12篇 |
排序方式: 共有3052条查询结果,搜索用时 437 毫秒
21.
Does altered biomechanics cause marrow edema? 总被引:21,自引:0,他引:21
22.
23.
24.
Carol Smillie B.N. B.Ed. M.S.C. Katherine Coffin B.A. ME.D. Kathryn Porter B.A. Brenda Ryan B.A. M.B.A. 《Journal of community health》1988,13(3):156-170
The International Conference on Primary Health Care, meeting in Alma-Ata, in the Soviet Union, September 12, 1978, expressed the need for urgent action by all governments, all health and development workers and the world community, to protect and promote the health of all people of the world. The world was caught by the phrase which emerged from this conference, Health For All by the Year 2000 and many have examined the articles of the Alma-Ata declaration and tried to implement them in their corner of the world. This paper describes a community-based smoking-cessation program which was implemented in the province of Nova Scotia, Canada, during the years 1980–1984. Primary to this project was the belief that people have the right and the duty to participate individually and collectively in planning and implementing their health care. This paper describes one community's effort in putting this belief into practice.Carol Smillie, B.N. BE.d. M.S.c. is an Assistant Professor at the School of Nursing, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5, Katherine Coffin, BA, MEd is the Program Officer, Nova Scotia Office, Health Promotion Directorate Health and Welfare Canada, 5251 Duke Street, Halifax, Nova Scotia. Canada B3J 1P3. Kathryn Porter, B.A. (Gen)., is the Information and Education Coordinator, Nova Scotia Division Canadian Cancer Society. Brenda Ryan, B.A., M.B.A. is Program Evaluation Analysist, Nova Scotia Department of Health, 6088 Hollis Street, Halifax. Nova Scotia, Canada. This Project was funded by Health and Welfare Canada, Nova Scotia Department of Health, Nova Scotia Division Canadian Cancer Society, Requests for reprints should be addressed to: Professor Carol Smillie. 相似文献
25.
Nucleolar organiser regions in adenocarcinoma in situ and invasive adenocarcinoma of the cervix. 总被引:2,自引:2,他引:0
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J F Darne S V Polacarz E Sheridan D Anderson R Ginsberg F Sharp 《Journal of clinical pathology》1990,43(8):657-660
Silver binding nucleolar regions (AgNORs) were evaluated in normal endocervix, adenocarcinoma, and its potential precursor, adenocarcinoma in situ (AIS), in an attempt to increase an understanding of the natural history of cervical adenocarcinoma and to identify a marker for abnormal endocervical (atypical glandular) cells which could aid diagnosis and follow up of endocervical lesions. For every 50 cells the mean AgNOR counts were as follows: normal endocervical cells (n = 15) 79.8 (95% Cl 68-91); AIS (n = 20) 200.7 (95% Cl 182-219); and invasive adenocarcinoma (n = 30) 299 (271-328). There was no overlap between the groups of normal endocervical cells and invasive adenocarcinoma, but there was significant overlap between cases of invasive adenocarcinoma and carcinoma in situ. In six out of 17 cases with AIS, NOR count in adjacent morphologically normal glandular cells ("internal" controls) was increased when compared with the "external" (normal endocervical) control group. This suggests the presence of wider field changes not previously identified using routine histological methods. The findings suggest that AIS is a potential premalignant precursor of invasive adenocarcinoma, but that assessment of NORs is of no practical use in discriminating between the histological types of cervical carcinoma. 相似文献
26.
Cardiovascular risk factor prevention in black schoolchildren: two-year results of the "Know Your Body" program 总被引:2,自引:0,他引:2
P J Bush A E Zuckerman P K Theiss V S Taggart C Horowitz M J Sheridan H J Walter 《American journal of epidemiology》1989,129(3):466-482
A five-year intervention study of the effectiveness of the "Know Your Body" program in reducing coronary heart disease risk factors among black students in the District of Columbia, who were in grades 4-6 at baseline, was begun in 1983. Nine schools were stratified on socioeconomic status and randomly assigned to control and intervention groups. The "Know Your Body" curriculum focuses on nutrition, fitness, and the prevention of cigarette smoking. At baseline, 1,234 students were eligible for the screening in which the following target risk factors were measured: systolic and diastolic blood pressures, ponderosity index, triceps skinfold thickness, postexercise pulse recovery rate, serum total and high density lipoprotein (HDL) cholesterol, and serum thiocyanate. After two years of intervention, results indicated that the program may have had a favorable impact on the following risk factors: systolic and diastolic pressures, HDL cholesterol, ratio of total to HDL cholesterol, fitness (postexercise pulse recovery rate), and smoking. Significant net changes in the favorable direction also were found for health knowledge and attitude toward smoking. Blood pressure reduction was associated with decreased ponderosity and improved fitness, and increased HDL cholesterol was associated with decreased ponderosity. These results are consistent with other evaluations of the "Know Your Body" program, suggesting that the program may be effective in reducing chronic disease risk in diverse school populations. 相似文献
27.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
28.
Interstitial deletion of the long arm of chromosome 18, del(18)(q12.2q21.1): a report of three cases of an autosomal deletion with a mild phenotype. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of medical genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A Schinzel F Binkert D M Lillington M Sands R J Stocks R H Lindenbaum H Matthews H Sheridan 《Journal of medical genetics》1991,28(5):352-355
We describe three unrelated patients with apparently identical interstitial deletions of the segment (18) (q12.2q21.1). They were a short and markedly mentally retarded 5 year old girl, a macrocephalic and obese 2 1/2 year old boy with moderate mental retardation, and a macrocephalic, severely mentally retarded 5 year old boy. Findings common to all five liveborn patients so far identified as carrying this deletion include a pattern of minor dysmorphic features (prominent forehead, ptosis of the upper eyelids, full periorbital tissue, epicanthic folds, strabismus), muscular hypotonia, seizures, behavioural disorders, and lack of major malformations. 相似文献
29.
30.
Clonal Diversity and Turnover of Streptococcus mitis bv. 1 on Shedding and Nonshedding Oral Surfaces of Human Infants during the First Year of Life
下载免费PDF全文
![点击此处可从《Clinical and Vaccine Immunology : CVI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jennifer L. Kirchherr George H. Bowden Dorothy A. Richmond Michael J. Sheridan Katherine A. Wirth Michael F. Cole 《Clinical and Vaccine Immunology : CVI》2005,12(10):1184-1190
Streptococcus mitis bv. 1 is a pioneer colonizer of the human oral cavity. Studies of its population dynamics within parents and their infants and within neonates have shown extensive diversity within and between subjects. We examined the genetic diversity and clonal turnover of S. mitis bv. 1 isolated from the cheeks, tongue, and primary incisors of four infants from birth to 1 year of age. In addition, we compared the clonotypes of S. mitis bv. 1 isolated from their mothers' saliva collected in parallel to determine whether the mother was the origin of the clones colonizing her infant. Of 859 isolates obtained from the infants, 568 were unique clones. Each of the surfaces examined, whether shedding or nonshedding, displayed the same degree of diversity. Among the four infants it was rare to detect the same clone colonizing more than one surface at a given visit. There was little evidence for persistence of clones, but when clones were isolated on multiple visits they were not always found on the same surface. A similar degree of clonal diversity of S. mitis bv. 1 was observed in the mothers' saliva as in their infants' mouths. Clones common to both infant and mothers' saliva were found infrequently suggesting that this is not the origin of the infants' clones. It is unclear whether mucosal immunity exerts the environmental pressure driving the genetic diversity and clonal turnover of S. mitis bv. 1, which may be mechanisms employed by this bacterium to evade immune elimination. 相似文献