全文获取类型
收费全文 | 844篇 |
免费 | 64篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 49篇 |
妇产科学 | 12篇 |
基础医学 | 112篇 |
口腔科学 | 33篇 |
临床医学 | 95篇 |
内科学 | 226篇 |
皮肤病学 | 34篇 |
神经病学 | 19篇 |
特种医学 | 131篇 |
外科学 | 64篇 |
综合类 | 37篇 |
预防医学 | 31篇 |
眼科学 | 5篇 |
药学 | 48篇 |
中国医学 | 2篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 3篇 |
2021年 | 16篇 |
2020年 | 13篇 |
2019年 | 22篇 |
2018年 | 16篇 |
2017年 | 20篇 |
2016年 | 20篇 |
2015年 | 29篇 |
2014年 | 33篇 |
2013年 | 36篇 |
2012年 | 27篇 |
2011年 | 15篇 |
2010年 | 58篇 |
2009年 | 39篇 |
2008年 | 21篇 |
2007年 | 28篇 |
2006年 | 20篇 |
2005年 | 18篇 |
2004年 | 12篇 |
2003年 | 14篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 45篇 |
1997年 | 38篇 |
1996年 | 38篇 |
1995年 | 24篇 |
1994年 | 34篇 |
1993年 | 28篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 20篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1978年 | 4篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1974年 | 3篇 |
1956年 | 3篇 |
1955年 | 2篇 |
排序方式: 共有924条查询结果,搜索用时 17 毫秒
1.
2.
GP SCHWAB AL BLUM E BODNER B DALLEMAGNE K GLASER H KOOP F PACE W RÖSCH JR SIEWERT G WETSCHER 《Journal of gastroenterology and hepatology》1997,12(12):785-789
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper. 相似文献
3.
J N Clore H Estep H Ross-Clunis C O Watlington 《The Journal of clinical endocrinology and metabolism》1988,67(4):824-831
The role of the glucocorticoid (type II) receptor in the Na+ retention induced by cortisol is not known. The relative contribution of mineralocorticoid (type I) and type II receptor activation to changes in urinary Na+ and K+ excretion in man was studied using spironolactone and RU486 to inhibit type I and II receptors, respectively. Normal men eating a constant daily diet received either ACTH or cortisol for 5 days. Spironolactone (400 mg/day) inhibited ACTH (80 U/day)-induced kaliuresis, but not the Na+ retention produced by ACTH or cortisol (240 mg/day) and only blunted the modest Na+ retention induced by cortisol (120 mg/day). RU486 (1200 mg/day for the first 2 day) inhibited the first day kaliuresis and carbohydrate intolerance produced by cortisol, but did not affect the Na+ retention. Thus, the kaliuresis produced by cortisol and ACTH can be attributed to type II and type I receptor activation, respectively. The failure of RU486 to inhibit the Na+ retention induced by cortisol with evidence of adequate blockade of type II receptors indicates that the Na+ retention produced by cortisol is not mediated by type II receptor activation, but is, at least in part, mediated by the type I receptor. 相似文献
4.
5.
6.
Edward?J?HolloxEmail author Jane?Davies Uta?Griesenbach Juliana?Burgess Eric?WFW?Alton John?AL?Armour 《Journal of negative results in biomedicine》2005,4(1):9
Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in
lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in
copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic
fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with
CF. No significant association was found. 相似文献
7.
Two groups of 10 female roof rats were mated either in cycling or postpartum estrus to provide a quantitative comparison of copulatory behavior and to compare the stimulus requirements for the initiation of pregnancy. Animals in both estrous conditions were mated to one ejaculation, three ejaculations and to sexual satiety in repeated tests. The results indicate there were no differences between estrous conditions in the qualitative patterns of copulation but that males achieved more intromissions in the first series of postpartum tests than in cycling estrous tests. The stimulus requirements for pregnancy initiation were not found to vary as a function of estrous condition, however it was found that postpartum matings resulted in more pups per litter than did cycling estrous matings. The results were discussed with regard to the functional significance of species differences in copulatory behavior and in stimulus requirements for pregnancy. 相似文献
8.
Missense FGFR3 mutations create cysteine residues in thanatophoric dwarfism type I (TD1) 总被引:10,自引:1,他引:10
Rousseau F; el Ghouzzi V; Delezoide AL; Legeai-Mallet L; Le Merrer M; Munnich A; Bonaventure J 《Human molecular genetics》1996,5(4):509-512
Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with
micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced
thoracic cavity. In the most common subtype (TD1), femurs are curved, while
in TD2, straight femurs are associated with cloverleaf skull. Mutations in
the fibroblast growth factor receptor 3 (FGFR3) gene were identified in
both subtypes. While TD2 was accounted for by a single recurrent mutation
in the tyrosine kinase 2 domain, TD1 resulted from either stop codon
mutations or missense mutations in the extracellular domain of the gene.
Here, we report the identification of FGFR3 mutations in 25/26 TD cases.
Two novel missense mutations (Y373C and G370C) were detected in 8/26 and
1/26 TD1 cases respectively. Both mutations created cysteine residues in
the juxta extramembrane domain of the receptor. Sixteen cases carried the
previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon
FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically
homogeneous condition and give additional support to the view that newly
created cysteine residues in the extracellular domain of the protein play a
key role in the severity of the disease.
相似文献
9.
Immunogenicity of recombinant protective antigen and efficacy against aerosol challenge with anthrax
Williamson ED Hodgson I Walker NJ Topping AW Duchars MG Mott JM Estep J Lebutt C Flick-Smith HC Jones HE Li H Quinn CP 《Infection and immunity》2005,73(9):5978-5987
Immunization with a recombinant form of the protective antigen (rPA) from Bacillus anthracis has been carried out with rhesus macaques. Rhesus macaques immunized with 25 mug or more of B. subtilis-expressed rPA bound to alhydrogel had a significantly increased immunoglobulin G (IgG) response to rPA compared with macaques receiving the existing licensed vaccine from the United Kingdom (anthrax vaccine precipitated [AVP]), although the isotype profile was unchanged, with bias towards the IgG1 and IgG2 subclasses. Immune macaque sera from all immunized groups contained toxin-neutralizing antibody and recognized all the domains of PA. While the recognition of the N terminus of PA (domains 1 to 3) was predominant in macaques immunized with the existing vaccines (AVP and the U.S. vaccine anthrax vaccine adsorbed), macaques immunized with rPA recognized the N- and C-terminal domains of PA. Antiserum derived from immunized macaques protected macrophages in vitro against the cytotoxic effects of lethal toxin. Passive transfer of IgG purified from immune macaque serum into naive A/J mice conferred protection against challenge with B. anthracis in a dose-related manner. The protection conferred by passive transfer of 500 mug macaque IgG correlated significantly (P = 0.003; r = 0.4) with the titers of neutralizing antibody in donor macaques. Subsequently, a separate group of rhesus macaques immunized with 50 mug of Escherichia coli-derived rPA adsorbed to alhydrogel was fully protected against a target dose of 200 50% lethal doses of aerosolized B. anthracis. These data provide some preliminary evidence for the existence of immune correlates of protection against anthrax infection in rhesus macaques immunized with rPA. 相似文献
10.
Morphological analysis of degeneration and regeneration of syncytiotrophoblast in first trimester placental villi during organ culture 总被引:3,自引:1,他引:3
We have recently shown using dansyl-L-lysine exclusion studies that the
release of human chorionic gonadotrophin (HCG) in conjunction with L-
lactate dehydrogenase (LDH) from first trimester villi during organ culture
is symptomatic of syncytiotrophoblast degeneration. The purpose of this
study was to examine chorionic villi at the ultrastructural level in order
to determine events occurring during organ culture. The tissue was sampled
after 0, 24, 48 and 120 h in culture and processed for electron microscopy.
In addition to confirming the previously recorded syncytial degeneration,
the electron micrographs showed clearly the generation of a new
syncytiotrophoblast layer. The new layer, derived from differentiating
cytotrophoblast cells, was largely formed by 48 h and was maintained for at
least 120 h in culture. This study demonstrates a model which provides an
opportunity to study the differentiation of cytotrophoblast cells whilst
they retain their anatomical relationships within the villous structure.
相似文献