全文获取类型
收费全文 | 832篇 |
免费 | 101篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 47篇 |
妇产科学 | 11篇 |
基础医学 | 151篇 |
口腔科学 | 31篇 |
临床医学 | 110篇 |
内科学 | 214篇 |
皮肤病学 | 34篇 |
神经病学 | 27篇 |
特种医学 | 131篇 |
外科学 | 59篇 |
综合类 | 38篇 |
预防医学 | 29篇 |
眼科学 | 5篇 |
药学 | 34篇 |
中国医学 | 2篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 4篇 |
2021年 | 13篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 13篇 |
2017年 | 18篇 |
2016年 | 19篇 |
2015年 | 24篇 |
2014年 | 30篇 |
2013年 | 41篇 |
2012年 | 19篇 |
2011年 | 17篇 |
2010年 | 46篇 |
2009年 | 37篇 |
2008年 | 22篇 |
2007年 | 33篇 |
2006年 | 19篇 |
2005年 | 20篇 |
2004年 | 11篇 |
2003年 | 16篇 |
2002年 | 10篇 |
2001年 | 16篇 |
2000年 | 15篇 |
1999年 | 15篇 |
1998年 | 45篇 |
1997年 | 40篇 |
1996年 | 38篇 |
1995年 | 27篇 |
1994年 | 34篇 |
1993年 | 30篇 |
1992年 | 13篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 22篇 |
1988年 | 22篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 16篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 18篇 |
1976年 | 11篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1956年 | 3篇 |
排序方式: 共有948条查询结果,搜索用时 15 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.
4.
5.
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
6.
R P Phipps C Baecher J G Frelinger D P Penney P Keng D Brown 《European journal of immunology》1990,20(8):1723-1727
The purpose of this investigation was to determine whether subpopulations of murine lung fibroblasts produced interleukin 1 (IL 1). We previously identified two major populations of pulmonary fibroblasts based on the presence or absence of Thy-1. Thy-1+ and Thy-1- subsets synthesize fibronectin and type I and III collagen, but only the Thy-1- population displays class II major histocompatibility complex antigens after stimulation with interferon-gamma and presents antigen to T helper clones. Interestingly, in the current study we determined that only Thy-1- fibroblast lines and clones synthesized IL 1. Although constitutive production was low, tumor necrosis factor -alpha (TNF-alpha) stimulated 5-20-fold increases in IL 1 production in Thy-1- fibroblasts. The Thy-1+ fibroblasts did not produce IL 1 even after TNF-alpha treatment. Northern blot analysis of TNF-alpha treated cells revealed that in the Thy-1- subset increased mRNA levels for IL 1 alpha were detected, while IL 1 beta mRNA was not detected. Furthermore, IL 1 activity from TNF-alpha-treated Thy-1- fibroblast membranes and supernatants was completely neutralized by IL 1 alpha-specific antibodies. These observations support the hypothesis that the antigen-presenting Thy-1- subset is important for promoting the inflammation associated with pulmonary fibrosis. In addition, the existence of functional subsets of lung fibroblasts is further substantiated by differential expression of IL 1. 相似文献
7.
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
8.
Peritoneal exudate cells from strains of mice both resistant and susceptible to challenge with mouse hepatitis virus strain JHM were examined for extrinsic and intrinsic antiviral activity. Thioglycolate-elicited and resident peritoneal cells from uninfected mice were able to suppress viral growth in a permissive cell. The active cell in both populations is an adherent, radiation-resistant, Thy-1.2 antigen- and Ia antigen-negative cell. The suppression of virus replication was not related to nonspecific cellular cytotoxicity directed against the permissive host cell, and no interferon was detected. The expression of extrinsic antiviral activity was not related to the ability of the host to resist mouse hepatitis virus infection by virtue of either age or genetic background. The expression of intrinsic antiviral activity, on the other hand, correlated with the ability of the host to resist virus challenge, indicating a characteristic distinction between these two in vitro mechanisms of macrophage-mediated antiviral activity with regard to host resistance to viral infection. Further, the ability of a macrophage to support viral replication itself was independent of the ability of the macrophage to suppress virus growth in another cell. 相似文献
9.
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
10.