全文获取类型
收费全文 | 2119篇 |
免费 | 159篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 84篇 |
妇产科学 | 55篇 |
基础医学 | 315篇 |
口腔科学 | 49篇 |
临床医学 | 222篇 |
内科学 | 417篇 |
皮肤病学 | 32篇 |
神经病学 | 105篇 |
特种医学 | 168篇 |
外科学 | 213篇 |
综合类 | 147篇 |
预防医学 | 159篇 |
眼科学 | 32篇 |
药学 | 132篇 |
中国医学 | 24篇 |
肿瘤学 | 130篇 |
出版年
2023年 | 31篇 |
2022年 | 72篇 |
2021年 | 108篇 |
2020年 | 79篇 |
2019年 | 83篇 |
2018年 | 94篇 |
2017年 | 79篇 |
2016年 | 78篇 |
2015年 | 100篇 |
2014年 | 115篇 |
2013年 | 122篇 |
2012年 | 154篇 |
2011年 | 135篇 |
2010年 | 98篇 |
2009年 | 85篇 |
2008年 | 101篇 |
2007年 | 80篇 |
2006年 | 59篇 |
2005年 | 42篇 |
2004年 | 26篇 |
2003年 | 24篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 15篇 |
1999年 | 24篇 |
1998年 | 49篇 |
1997年 | 44篇 |
1996年 | 39篇 |
1995年 | 19篇 |
1994年 | 29篇 |
1993年 | 24篇 |
1992年 | 8篇 |
1991年 | 20篇 |
1990年 | 16篇 |
1989年 | 19篇 |
1988年 | 18篇 |
1987年 | 28篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1971年 | 4篇 |
1967年 | 8篇 |
排序方式: 共有2298条查询结果,搜索用时 15 毫秒
1.
2.
Gudrun Aspelund Elaa M Mahdi David H Rothstein Derek S Wakeman 《Journal of gastroenterology and hepatology》2019,34(6):966-974
Choledochal cysts (CDCs) and biliary atresia (BA) are rare pediatric hepatobiliary anomalies that require surgical intervention due to increased risk of malignancy and liver failure, respectively. The underlying disease and operative procedures place patients at risk for long‐term complications, which may continue to affect them into adulthood. Lack of a transitional care model in the health‐care system potentiates the challenges they will face following aging out of their pediatric providers' care. We sought to elucidate the long‐term complications and challenges patients with CDCs and BA face, review the current literature regarding transitioning care, and propose guidelines aiding adult providers in continued care and surveillance of these patients. A literature review was performed to assess short‐term and long‐term complications after surgery and the current standards for transitioning care in patients with a history of CDCs and BA. While transitional programs exist for patients with other gastrointestinal diseases, there are few that focus on CDCs or BA. Generally, authors encourage medical record transmission from pediatric to adult providers, ensuring accuracy of information and compliance with treatment plans. Patients with CDCs are at risk for developing biliary malignancies, cholangitis, and anastomotic strictures after resection. Patients with BA develop progressive liver failure, necessitating transplantation. There are no consensus guidelines regarding timing of follow up for these patients. Based on the best available evidence, we propose a schema for long‐term surveillance. 相似文献
3.
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
4.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
5.
6.
7.
Jamie H Macdonald Mysore K Phanish Samuele M Marcora Mahdi Jibani Lionel L O Bloodworth Jeffrey M P Holly Andrew B Lemmey 《Journal of renal nutrition》2004,14(4):248-252
BACKGROUND: Hemodialysis (HD) patients typically have reduced muscle mass and diminished functional capacity. The role of the muscle insulin-like growth factors (IGFs), a principal anabolic system that is involved in protein synthesis and that has downregulation that is implicated in muscle loss in animal models of uremia, has previously not been assessed in vivo in HD patients. METHODS: Seventeen HD patients were compared cross-sectionally with 17 age-, sex-, and body mass index-matched healthy controls. Body composition was assessed by dual energy x-ray absorptiometry and bioelectrical impedance spectrometry; functional capacity by hand grip strength, quadriceps strength, and 30-second sit-to-stand test; systemic inflammation by tumor necrosis factor-alpha (TNF-alpha) and TNF receptor 1 (TNFR1); serum and muscle IGF-I and IGFBP-3 by radioimmunoassay; and fragmentation of serum IGFBP-3 by Western immunoblotting. RESULTS: Appendicular lean mass was significantly decreased in HD patients compared with controls (17.6 +/- 0.9 versus 21.5 +/- 1.5 kg, P < .05), as were all measures of functional capacity (P < .01 to .001), and highly significant positive correlations between appendicular lean mass and functional capacity were evident (appendicular lean mass and hand-grip strength, quadriceps strength, 30-second sit-to-stand test, all P < .001). TNF-alpha and TNFR1 were elevated in patients (P < .001). Although serum IGF-I and IGFBP-3 levels did not differ between the groups (P = .295 and .379 respectively), fragmented IGFBP-3 levels were increased (53.1 +/- 16.0 versus 29.81 +/- 15.3%, P < .005). In contrast, muscle IGF-I was substantially diminished in the patient group (n = 7) relative to control (n = 5) levels (0.84 +/- 0.06 versus 2.78 +/- 1.80 pg/microg, P < .05). CONCLUSIONS: We provide evidence of reduced IGF-I in HD patients' skeletal muscle that may be a causal factor in the muscle wasting characteristic of this population. Future research should determine the exact consequences and causes of alterations to the muscle IGF system in HD patients. 相似文献
8.
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
9.
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
10.
Najmabadi H Nishimura C Kahrizi K Riazalhosseini Y Malekpour M Daneshi A Farhadi M Mohseni M Mahdieh N Ebrahimi A Bazazzadegan N Naghavi A Avenarius M Arzhangi S Smith RJ 《American journal of medical genetics. Part A》2005,(2):132-137
Hereditary hearing loss (HHL) is a very common disorder. When inherited in an autosomal recessive manner, it typically presents as an isolated finding. Interestingly and unexpectedly, in spite of extreme heterogeneity, mutations in one gene, GJB2, are the most common cause of congenital severe-to-profound deafness in many different populations. In this study, we assessed the contributions made by GJB2 mutations and chromosome 13 g.1777179_2085947del (the deletion more commonly known as del (GJB6-D13S1830) that includes a portion of GJB6 and is hereafter called Delta(GJB6-D13S1830)) to the autosomal recessive non-syndromic deafness (ARNSD) genetic load in Iran. Probands from 664 different nuclear families were investigated. GJB2-related deafness was found in 111 families (16.7%). The carrier frequency of the 35delG mutation showed a geographic variation that is supported by studies in neighboring countries. Delta(GJB6-D13S1830) was not found. Our prevalence data for GJB2-related deafness reveal a geographic pattern that mirrors the south-to-north European gradient and supports a founder effect in southeastern Europe. 相似文献