全文获取类型
收费全文 | 1586篇 |
免费 | 166篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 77篇 |
妇产科学 | 27篇 |
基础医学 | 176篇 |
口腔科学 | 80篇 |
临床医学 | 232篇 |
内科学 | 283篇 |
皮肤病学 | 18篇 |
神经病学 | 70篇 |
特种医学 | 272篇 |
外科学 | 137篇 |
综合类 | 48篇 |
一般理论 | 2篇 |
预防医学 | 188篇 |
眼科学 | 23篇 |
药学 | 68篇 |
肿瘤学 | 80篇 |
出版年
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 11篇 |
2018年 | 25篇 |
2017年 | 12篇 |
2016年 | 23篇 |
2015年 | 27篇 |
2014年 | 33篇 |
2013年 | 42篇 |
2012年 | 39篇 |
2011年 | 48篇 |
2010年 | 53篇 |
2009年 | 39篇 |
2008年 | 42篇 |
2007年 | 61篇 |
2006年 | 55篇 |
2005年 | 49篇 |
2004年 | 42篇 |
2003年 | 56篇 |
2002年 | 31篇 |
2001年 | 36篇 |
2000年 | 38篇 |
1999年 | 42篇 |
1998年 | 70篇 |
1997年 | 80篇 |
1996年 | 90篇 |
1995年 | 59篇 |
1994年 | 46篇 |
1993年 | 53篇 |
1992年 | 37篇 |
1991年 | 32篇 |
1990年 | 32篇 |
1989年 | 51篇 |
1988年 | 57篇 |
1987年 | 43篇 |
1986年 | 39篇 |
1985年 | 41篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 8篇 |
1969年 | 10篇 |
1967年 | 6篇 |
1966年 | 6篇 |
排序方式: 共有1782条查询结果,搜索用时 15 毫秒
21.
Oscillatory motion of the normal cervical spinal cord 总被引:2,自引:0,他引:2
22.
Members of the ALP/Enigma family of PDZ-LIM proteins play a role in cytoskeletal anchorage and mutations in at least one member of this family are associated with human cardiomyopathy. Here, we describe the analysis of the Caenorhabditis elegans alp-1 gene. alp-1 is predicted to encode the entire nematode ALP/Enigma protein family, consisting of one ALP-related protein with a single LIM domain and three Enigma-like proteins containing four LIM domains. We demonstrate that the ALP-1 proteins are expressed in muscle cells, where they localize to actin anchorage and muscle attachment sites. We show that the PDZ domain of the ALP-1 proteins is sufficient to target the protein to the dense bodies, which are important actin anchorage sites in C. elegans body wall muscle. We demonstrate that the C. elegans ALP/Enigma proteins are also localized to cell-cell junctions and to both epithelial and muscle cell nuclei. These findings suggest new roles for the ALP/Enigma protein family that may lead to the understanding of their involvement in cardiomyopathy. 相似文献
23.
Periosteal Ewing sarcoma 总被引:3,自引:0,他引:3
24.
25.
In a prospective, randomized study of insemination with donor semen,
intracervical insemination by straw was compared with insemination using a
cervical cap with an intracervical reservoir. A total of 91 patients
completed 486 treatment cycles. There were no significant differences in
age, parity, indication for insemination by donor, or method of cycle
monitoring between women who became pregnant and those who did not conceive
with either insemination method. In 236 standard intracervical insemination
cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients
conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude
pregnancy rates and the cumulative pregnancy rates calculated by the
Kaplan-Meier life-table method were significantly different (chi(2)-test, P
< 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates
in artificial insemination with cryopreserved donor semen may be improved
by the use of a cervical cap when compared to cervical insemination by
straw. The use of the cervical cap may prolong the exposure of the
spermatozoa to the cervical mucus and prevent the backflow of semen into
the vagina.
相似文献
26.
27.
Meniscal abnormalities: prospective correlation of double-contrast arthrography and arthroscopy 总被引:2,自引:0,他引:2
In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed. 相似文献
28.
29.
Coralline hydroxyapatite bone graft substitutes: preliminary report of radiographic evaluation 总被引:1,自引:0,他引:1
A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties. 相似文献
30.
Day DJ; Speiser PW; Schulze E; Bettendorf M; Fitness J; Barany F; White PC 《Human molecular genetics》1996,5(12):2039-2048
Steroid 21-hydroxylase deficiency is among the most common inborn errors of
metabolism in man. Characterization of mutations in the 21- hydroxylase
gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase
chain reaction (PCR). The most common mutation is conversion of an A or C
at nt656 to a G in the second intron causing aberrant splicing of mRNA.
Homozygosity for nt656G is associated with profoundly deficient adrenal
cortisol and aldosterone synthesis, secondary hypersecretion of adrenal
androgens, and a severe form of congenital adrenal hyperplasia (CAH)
characterized by ambiguous genitalia and/or sodium wasting in newborns.
During the course of genetic analysis of CYP21 mutations in CAH families,
we and others have noticed a number of relatives genotyped as nt656G
homozygotes, yet showing no clinical signs of disease. A number of lines of
evidence have led us to propose that the putative asymptomatic nt656G/G
individuals are incorrectly typed due to dropout of one haplotype during
PCR amplification of CYP21. For prenatal diagnosis, we recommend that
microsatellite typing be used as a supplement to CYP21 genotyping in order
to resolve ambiguities at nt656.
相似文献