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   483378篇
  免费   65703篇
  国内免费   8522篇
耳鼻咽喉   5692篇
儿科学   14891篇
妇产科学   7699篇
基础医学   57417篇
口腔科学   14987篇
临床医学   52916篇
内科学   71585篇
皮肤病学   9143篇
神经病学   39716篇
特种医学   14453篇
外国民族医学   35篇
外科学   52872篇
综合类   57366篇
现状与发展   15篇
一般理论   39篇
预防医学   46413篇
眼科学   6959篇
药学   42387篇
  439篇
中国医学   36325篇
肿瘤学   26254篇
  2023年   5840篇
  2022年   10105篇
  2021年   15908篇
  2020年   19082篇
  2019年   29753篇
  2018年   27079篇
  2017年   25217篇
  2016年   21950篇
  2015年   21132篇
  2014年   32078篇
  2013年   34119篇
  2012年   29652篇
  2011年   31797篇
  2010年   26646篇
  2009年   21445篇
  2008年   21488篇
  2007年   20579篇
  2006年   18598篇
  2005年   16329篇
  2004年   13959篇
  2003年   12392篇
  2002年   10320篇
  2001年   8846篇
  2000年   6646篇
  1999年   4913篇
  1998年   3894篇
  1997年   3781篇
  1996年   3291篇
  1995年   3177篇
  1994年   2958篇
  1993年   2419篇
  1992年   2386篇
  1991年   2079篇
  1990年   1847篇
  1989年   1625篇
  1988年   1531篇
  1987年   1324篇
  1985年   4036篇
  1984年   5018篇
  1983年   3509篇
  1982年   3999篇
  1981年   3766篇
  1980年   3381篇
  1979年   3079篇
  1978年   2691篇
  1977年   2042篇
  1976年   2306篇
  1975年   1758篇
  1974年   1537篇
  1973年   1390篇
排序方式: 共有10000条查询结果,搜索用时 796 毫秒
51.
52.
53.
穴位埋线是长效针灸,是在传统针具和针法基础上建立和发展起来的,是针灸技术的发展和延伸,穴位埋线的核心技术是穿刺技术,穴位埋线的三大要素中,针具、埋藏物、穿刺技巧之间是互相影响、互相促进的。针具的改进成功实现了穴位埋线疗法的第一次飞跃,埋藏物的改进成功实现了穴位埋线疗法的第二次飞跃,穿刺技术的改进和创新是穴位埋线疗法的第三次飞跃。  相似文献   
54.
55.
56.
Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).  相似文献   

57.
58.
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   
59.
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   
60.
This article focuses on the functional features of positive-pressure ventilators, the modes of invasive and non-invasive mechanical ventilation, and the main ventilator settings. It also highlights the potential complications of mechanical ventilation, the basic principles of weaning, and the pathophysiological basis of patient-ventilator dyssynchrony.  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