全文获取类型
收费全文 | 881篇 |
免费 | 68篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 45篇 |
妇产科学 | 5篇 |
基础医学 | 96篇 |
口腔科学 | 25篇 |
临床医学 | 82篇 |
内科学 | 195篇 |
皮肤病学 | 20篇 |
神经病学 | 22篇 |
特种医学 | 124篇 |
外科学 | 74篇 |
综合类 | 133篇 |
一般理论 | 1篇 |
预防医学 | 42篇 |
眼科学 | 11篇 |
药学 | 34篇 |
中国医学 | 1篇 |
肿瘤学 | 44篇 |
出版年
2023年 | 7篇 |
2022年 | 34篇 |
2021年 | 51篇 |
2020年 | 20篇 |
2019年 | 29篇 |
2018年 | 41篇 |
2017年 | 21篇 |
2016年 | 18篇 |
2015年 | 26篇 |
2014年 | 44篇 |
2013年 | 21篇 |
2012年 | 42篇 |
2011年 | 23篇 |
2010年 | 40篇 |
2009年 | 43篇 |
2008年 | 41篇 |
2007年 | 26篇 |
2006年 | 15篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 46篇 |
1997年 | 40篇 |
1996年 | 31篇 |
1995年 | 19篇 |
1994年 | 27篇 |
1993年 | 22篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 25篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1967年 | 1篇 |
排序方式: 共有966条查询结果,搜索用时 15 毫秒
1.
Krishna Pillai Javid Akhter Terence C. Chua Mena Shehata Nayef Alzahrani Issan Al-Alem David L. Morris 《Medicine》2015,94(9)
Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. 相似文献
2.
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.
A Alzahrani M Anvari B Dallemagne D Mutter J Marescaux 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(1):97-100
OBJECTIVE: We report on 3 patients who underwent laparoscopic antireflux procedures for persistent symptoms of GERD after biopolymer injection. METHODS: Experienced laparoscopic surgeons completed all 3 procedures laparoscopically. In 2 patients, there was an extramural extravasation of the polymer outside and adherent to the esophageal wall. In these patients, a partial posterior fundoplication was used. The third patient, who had the polymer material deposits removed preoperatively by endoscopic mucosal resection, underwent a Nissen fundoplication. RESULTS: Postoperative recovery was uneventful in all cases. At follow-up of 6 to 12 months, all patients were symptom free, off medical therapy, and experiencing no dysphagia. CONCLUSION: Surgical therapy for patients after failed biopolymer injection is safe and effective. The choice of surgery may depend on whether the polymer mass can be removed preoperatively. 相似文献
6.
7.
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