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   110183篇
  免费   47322篇
  国内免费   1751篇
耳鼻咽喉   1833篇
儿科学   4958篇
妇产科学   1384篇
基础医学   19856篇
口腔科学   5657篇
临床医学   16679篇
内科学   29333篇
皮肤病学   7908篇
神经病学   15085篇
特种医学   3169篇
外国民族医学   6篇
外科学   18093篇
综合类   4637篇
现状与发展   10篇
一般理论   28篇
预防医学   6852篇
眼科学   2351篇
药学   9060篇
  30篇
中国医学   2751篇
肿瘤学   9576篇
  2024年   83篇
  2023年   524篇
  2022年   1050篇
  2021年   2907篇
  2020年   6170篇
  2019年   11784篇
  2018年   11142篇
  2017年   12449篇
  2016年   12998篇
  2015年   13279篇
  2014年   13501篇
  2013年   14094篇
  2012年   6912篇
  2011年   7066篇
  2010年   10677篇
  2009年   6812篇
  2008年   4213篇
  2007年   3006篇
  2006年   2977篇
  2005年   2592篇
  2004年   2295篇
  2003年   2188篇
  2002年   2106篇
  2001年   1745篇
  2000年   1605篇
  1999年   1087篇
  1998年   372篇
  1997年   361篇
  1996年   286篇
  1995年   219篇
  1994年   228篇
  1993年   158篇
  1992年   327篇
  1991年   285篇
  1990年   261篇
  1989年   227篇
  1988年   183篇
  1987年   175篇
  1986年   155篇
  1985年   108篇
  1984年   67篇
  1983年   50篇
  1982年   67篇
  1981年   56篇
  1980年   48篇
  1979年   63篇
  1978年   50篇
  1975年   34篇
  1974年   27篇
  1973年   32篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
It is well recognized that the world population is ageing rapidly. Therefore, it is important to understand ageing processes at the cellular and molecular levels to predict the onset of age‐related diseases and prevent them. Recent research has focused on the identification of ageing biomarkers, including those associated with the properties of the Golgi apparatus. In this context, Golgi‐mediated glycosylation of proteins has been well characterized. Additionally, other studies show that the secretion of many compounds, including pro‐inflammatory cytokines and extracellular matrix–degrading enzymes, is modified during ageing, resulting in physical and functional skin degradation. Since the Golgi apparatus is a central organelle of the secretory pathway, we investigated its structural organization in senescent primary human dermal fibroblasts using confocal and electron microscopy. In addition, we monitored the expression of Golgi‐related genes in the same cells. Our data showed a marked alteration in the Golgi morphology during replicative senescence. In contrast to its small and compact structure in non‐senescent cells, the Golgi apparatus exhibited a large and expanded morphology in senescent fibroblasts. Our data also demonstrated that the expression of many genes related to Golgi structural integrity and function was significantly modified in senescent cells, suggesting a relationship between Golgi apparatus function and ageing.  相似文献   
13.
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy.  相似文献   
14.
15.
16.
17.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
18.
19.
20.
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