全文获取类型
收费全文 | 1139篇 |
免费 | 70篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 56篇 |
妇产科学 | 16篇 |
基础医学 | 109篇 |
口腔科学 | 14篇 |
临床医学 | 90篇 |
内科学 | 254篇 |
皮肤病学 | 17篇 |
神经病学 | 31篇 |
特种医学 | 124篇 |
外科学 | 103篇 |
综合类 | 111篇 |
预防医学 | 70篇 |
眼科学 | 3篇 |
药学 | 67篇 |
中国医学 | 1篇 |
肿瘤学 | 152篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 20篇 |
2020年 | 7篇 |
2019年 | 15篇 |
2018年 | 19篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 28篇 |
2014年 | 35篇 |
2013年 | 34篇 |
2012年 | 46篇 |
2011年 | 36篇 |
2010年 | 55篇 |
2009年 | 57篇 |
2008年 | 56篇 |
2007年 | 51篇 |
2006年 | 32篇 |
2005年 | 47篇 |
2004年 | 32篇 |
2003年 | 46篇 |
2002年 | 42篇 |
2001年 | 45篇 |
2000年 | 32篇 |
1999年 | 29篇 |
1998年 | 53篇 |
1997年 | 47篇 |
1996年 | 36篇 |
1995年 | 21篇 |
1994年 | 32篇 |
1993年 | 24篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 11篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 28篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 15篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1967年 | 2篇 |
排序方式: 共有1226条查询结果,搜索用时 31 毫秒
1.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
2.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
3.
4.
5.
Evaluation of a new enzyme-linked immunosorbent assay test for rotavirus antigen in faeces 总被引:6,自引:0,他引:6 下载免费PDF全文
A new commercial test for the diagnosis of rotavirus gastroenteritis was assessed. With some modifications it compared favourably with electron microscopy and immunofluorescence. 相似文献
6.
Pelosi G Scarpa A Veronesi G Spaggiari L Del Curto B Moore PS Maisonneuve P Sonzogni A Masullo M Viale G 《Virchows Archiv : an international journal of pathology》2005,447(6):969-977
Nuclear translocation of β-catenin has been correlated with epidermal growth factor receptor (EGFR) overexpression/activation
in nonsmall cell lung cancer. Less is known on β-catenin transactivation in high-grade pulmonary neuroendocrine tumors and
on the status of β-catenin activating EGFR and human epidermal growth factor receptor 2 (HER-2) or β-catenin target genes
cyclin D1 and matrix metalloproteinase-7 (MMP-7). β-catenin immunoreactivity was evaluated in 51 large-cell neuroendocrine
carcinomas (LCNEC) and 45 small-cell lung carcinomas (SCLC). Nineteen cases were assessed for β-catenin gene exon 3 mutations, expression of MMP-7, and expression/gene amplification of EGFR, HER-2, and cyclin D1. β-catenin was
expressed in all 96 high-grade neuroendocrine tumors, the vast majority (94%) showing >50% immunopositive cells. A disarrayed
immunoreactivity, however, was commonly encountered consisting in variably altered membrane-associated patterns of staining
along with progressive accumulation of cytoplasmic immunoreactivity. In LCNEC, but not in SCLC, the disarrayed patterns correlated
with EGFR and HER-2 protein expression. β-catenin nuclear accumulation was found in nine tumors, including seven LCNEC and
two SCLC, and was always associated with disarrayed immunoreactivity and increased MMP-7, but not cyclin D1 expression. These
cases, however, did not show β-catenin gene mutations or EGFR and HER-2 gene amplification or expression. No association was found between nuclear β-catenin and
any clinicopathological variable including patients' survival. The subcellular compartmentalization of β-catenin is profoundly
altered in high-grade pulmonary neuroendocrine tumors. A minor subset of these tumors shows β-catenin nuclear accumulation
in association with increased expression of MMP-7, but not of cyclin D1, independent of EGFR and HER-2 gene amplification
or expression.
The authors have no significant financial or other relationship with the manufacturers of any commercial products or commercial
services presented in this paper 相似文献
7.
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
8.
K-ras gene mutational analysis supports a monoclonal origin of biphasic pleomorphic carcinoma of the lung. 总被引:2,自引:0,他引:2
Giuseppe Pelosi Aldo Scarpa Michela Manzotti Giulia Veronesi Lorenzo Spaggiari Filippo Fraggetta Oscar Nappi Elvira Benini Felice Pasini Davide Antonello Antonio Iannucci Patrick Maisonneuve Giuseppe Viale 《Modern pathology》2004,17(5):538-546
We investigated 27 pleomorphic carcinomas of the lung for exon 1 K-ras gene mutations using polymerase chain reaction-single-strand conformation polymophism analysis and direct sequencing. All pleomorphic carcinomas were biphasic, that is, composed of an adeno-, squamous- or large-cell-carcinomatous component associated with a spindle- and/or giant-cell component. Of 27 cases, six (22%) showed K-ras codon 12 mutations, which is a figure higher than that previously reported on in pure sarcoma-like pleomorphic carcinomas. Five tumors displayed the same mutation in both the epithelial and the sarcomatoid components, whereas in one tumor the mutation was restricted to the epithelial component. All mutations occurred in smokers, and were transversions, including GGT (glycine) to TGT (cysteine) change in two cases, to GCT (alanine) in two and to GTT (valine) in two. No significant relationships were found between the occurrence and type of mutations and patients' survival or any other clinicopathological variable, suggesting that K-ras mutations are early events in the development of these tumors. Our results indicate that most, though not all, biphasic pleomorphic carcinomas of the lung are monoclonal in origin, and that cigarette smoking may have a causative role in the development of K-ras alterations in these tumors, as all mutations are transversions. 相似文献
9.
10.