首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4999篇
  免费   349篇
  国内免费   8篇
耳鼻咽喉   56篇
儿科学   202篇
妇产科学   160篇
基础医学   613篇
口腔科学   86篇
临床医学   492篇
内科学   895篇
皮肤病学   52篇
神经病学   417篇
特种医学   236篇
外科学   778篇
综合类   107篇
一般理论   2篇
预防医学   461篇
眼科学   60篇
药学   214篇
中国医学   6篇
肿瘤学   519篇
  2023年   42篇
  2022年   60篇
  2021年   173篇
  2020年   101篇
  2019年   120篇
  2018年   145篇
  2017年   105篇
  2016年   119篇
  2015年   116篇
  2014年   185篇
  2013年   211篇
  2012年   330篇
  2011年   312篇
  2010年   169篇
  2009年   182篇
  2008年   272篇
  2007年   275篇
  2006年   235篇
  2005年   230篇
  2004年   213篇
  2003年   208篇
  2002年   210篇
  2001年   148篇
  2000年   111篇
  1999年   89篇
  1998年   33篇
  1997年   32篇
  1996年   39篇
  1995年   27篇
  1994年   25篇
  1993年   19篇
  1992年   69篇
  1991年   45篇
  1990年   65篇
  1989年   63篇
  1988年   63篇
  1987年   53篇
  1986年   60篇
  1985年   55篇
  1984年   28篇
  1983年   29篇
  1982年   22篇
  1981年   19篇
  1979年   35篇
  1976年   16篇
  1973年   14篇
  1971年   14篇
  1970年   17篇
  1969年   18篇
  1968年   16篇
排序方式: 共有5356条查询结果,搜索用时 46 毫秒
1.
2.
3.
Background A high Mandard score implies a non-response to chemotherapy in oesophageal adenocarcinoma. However, some patients exhibit tumour volume reduction and a nodal response despite a high score. This study examines survival and recurrence patterns in these patients.Methods Clinicopathological factors were analysed using multivariable Cox regression assessing time to death and recurrence. Computed tomography-estimated tumour volume change was examined in a subgroup of consecutive patients.Results Five hundred and fifty-five patients were included. Median survival was 55 months (Mandard 1–3) and 21 months (Mandard 4 and 5). In the Mandard 4 and 5 group (332 patients), comparison between complete nodal responders and persistent nodal disease showed improved survival (90 vs 18 months), recurrence rates (locoregional 14.75 vs 28.74%, systemic 24.59 vs 48.42%) and circumferential resection margin positivity (22.95 vs 68.11%). Complete nodal response independently predicted improved survival (hazard ratio 0.34 (0.16–0.74). Post-chemotherapy tumour volume reduction was greater in patients with a complete nodal response (−16.3 vs −7.7 cm3, p = 0.033) with no significant difference between Mandard groups.Conclusion Patients with a complete nodal response to chemotherapy have significantly improved outcomes despite a poor Mandard score. High Mandard score does not correspond with a non-response to chemotherapy in all cases and patients with nodal downstaging may still benefit from adjuvant chemotherapy.Subject terms: Oesophageal cancer, Surgical oncology  相似文献   
4.

Background

In the emergency department, rib fractures are a common finding in patients who sustain chest trauma. Rib fractures may be a sign of significant, underlying pathology, especially in the elderly patients where rib fractures are associated with significant morbidity and mortality. To date, no studies have evaluated the ability of ultrasound to detect rib fractures using cadaver models and subsequently use this model as a teaching tool.

Objectives

The purpose of this study was to determine if it is possible to generate rib fractures on cadaver models which could be accurately identified using ultrasound.

Methods

This was a cross-sectional study performed during one session at a cadaver lab. A single hemithorax from four adult cadavers were used as models. Single rib fractures on each of rib five through eight were created. Four subjects, blinded to the normal versus fractured ribs, were asked to identify the presence of a fracture on each rib.

Results

A total of 8 of 16 potential ribs had fractured induced by study staff. Mean accuracy was 55% for all subjects. The overall sensitivity and specificity for detecting rib fractures was 50% (CI: 31.89–68.11) and 59.38% (CI: 35.69–73.55) respectively. The overall PPV and NPV was 55.17% and 54.29% respectively.

Conclusions

In this pilot study, subjects were not able to detect induced rib fractures using ultrasound on cadaver models. The use of this model as a teaching tool in the detection of rib fractures requires further investigation.  相似文献   
5.
6.
7.
Thin slices of teleost retina continue to grow in culture   总被引:2,自引:0,他引:2  
Thin slices of differentiated fish retinas were maintained up to 5 days in culture conditions where they exhibited properties essentially identical to those found in retinas of intact animals. Retinal slices were prepared by embedding eyecups from young fish in agarose and sectioning them on a vibratome. Phenotypic integrity of specific cell types was maintained, as demonstrated by specific antibody staining patterns. Stem cells in the retinal margin and presumptive rod progenitor cells in the outer nuclear layer continued to proliferate in vitro, just as they do in vivo. Some of these cells differentiated in vitro as demonstrated by labelling both cell division and cell phenotype. After several days in culture, some regeneration-like responses were observed, such as growth of neurites and swelling of cell bodies in the ganglion cell layer. This retinal slice preparation appears to offer a unique opportunity for studying the interactions among developing retinal cells.  相似文献   
8.
9.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
10.
Strahlentherapie und Onkologie - Several randomized trials have demonstrated that men with localized prostate cancer benefit from the use of short-term neoadjuvant androgen deprivation therapy...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号