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   616380篇
  免费   47350篇
  国内免费   15765篇
耳鼻咽喉   7482篇
儿科学   15732篇
妇产科学   9599篇
基础医学   46366篇
口腔科学   14172篇
临床医学   65900篇
内科学   75361篇
皮肤病学   7661篇
神经病学   31639篇
特种医学   15046篇
外国民族医学   50篇
外科学   63177篇
综合类   102980篇
现状与发展   38篇
一般理论   56篇
预防医学   63639篇
眼科学   7828篇
药学   60536篇
  777篇
中国医学   65303篇
肿瘤学   26153篇
  2023年   10251篇
  2022年   16074篇
  2021年   26518篇
  2020年   25077篇
  2019年   28241篇
  2018年   25749篇
  2017年   22966篇
  2016年   21282篇
  2015年   20157篇
  2014年   40728篇
  2013年   42229篇
  2012年   37373篇
  2011年   40044篇
  2010年   32449篇
  2009年   28711篇
  2008年   27242篇
  2007年   27908篇
  2006年   24208篇
  2005年   20927篇
  2004年   17324篇
  2003年   15283篇
  2002年   11853篇
  2001年   10428篇
  2000年   8740篇
  1999年   7210篇
  1998年   5935篇
  1997年   5453篇
  1996年   4684篇
  1995年   4351篇
  1994年   4024篇
  1993年   3232篇
  1992年   3174篇
  1991年   2791篇
  1990年   2423篇
  1989年   2239篇
  1988年   2096篇
  1987年   1810篇
  1986年   1670篇
  1985年   5021篇
  1984年   5961篇
  1983年   4194篇
  1982年   4906篇
  1981年   4271篇
  1980年   3782篇
  1979年   3469篇
  1978年   2960篇
  1977年   2236篇
  1976年   2538篇
  1975年   1866篇
  1974年   1634篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
41.
42.
目的 基于网络药理学和分子对接技术探究黄芪-赤芍配伍对治疗慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)的作用机制。方法 利用TCMSP,Pharmmaper数据库,筛选黄芪-赤芍治疗COPD的活性成分和潜在靶点;结合Genecards数据库挖掘的COPD相关靶点,对黄芪-赤芍药对与COPD靶点进行PPI网络构建,交互处理得到黄芪-赤芍药对治疗COPD的关键靶点,并进行GO分析和KEGG通路富集分析;并采用分子对接技术将主要活性成分与TNF-α(肿瘤坏死因子),IL-6(白细胞介素6)等进行分子对接;最后利用A549炎症细胞与人脐静脉内皮细胞缺氧损伤模型进行体外细胞实验对结果加以验证。结果 黄芪-赤芍药对中44个有效成分作用于COPD,核心成分为:槲皮素、山奈酚、丁子香萜、芍药苷、(2R,3R)-4-methoxyl-distylin、二氢异黄酮;黄芪-赤芍药对通过IL6、PTGS2、TNF等113个靶蛋白,调控Ras、PI3KAkt、IL-17等多条信号通路治疗COPD,且分子对接结果显示槲皮素、山奈酚、丁子香萜、芍药苷与IL-6、PTGS2、TNF大分子蛋白有良好的结合性,体外细胞试验证实,槲皮素与山奈酚均能减少IL-8,MMP-9炎症因子的分泌,具有不同程度的抗炎效果;芍药苷有明显的扩血管、抗血栓之效。结论 黄芪-赤芍药对治疗COPD具有多成分、多靶点、多通路、整体调节的作用特点。初步揭示了黄芪-赤芍药对通过抑制炎症反应、调节上皮细胞生长增强保护屏障等预测出黄芪-赤芍药对治疗COPD的潜在作用机制,以期为其活性成分的药效物质基础提供理论研究和思路。  相似文献   
43.
人工智能(Artificial Intelligence,AI)的蓬勃兴起为现代社会带来了前所未有的机遇,中医药是中华民族传承千年的文化瑰宝。随着人工智能技术不断在中医药领域的科技创新中崭露头角,二者的融合不断加深,人工智能在中医药领域的发展前景、争议挑战也引发了诸多思考。本文将从人工智能在中医药领域的应用入手,对人工智能辅助中医诊断、智能决策与数据挖掘、健康管理及中草药现代化研究等方面,就近年来国内外研究进展进行总结与分析,以期为AI视域下实现中医药现代化、智能化赋能。  相似文献   
44.
胆囊切除术是公认的胆囊良性疾病的治愈手段,国内外学术界对于手术适应证和手术时机已有明确共识。近年来,“保胆手术”治疗胆囊良性疾病颇受热议,一些医生将“保护胆囊”的学术观点等同于“保留胆囊”的手术技术,这种误解可能导致病人出现差异性的预后。因此,临床医师应明晰“保护胆囊”理念与“保胆手术”的差别,对胆囊良性疾病的诊疗原则有正确的理解和应用。  相似文献   
45.
PurposeTo investigate the safety and efficacy of thyroid artery embolization (TAE) in the treatment of nodular goiter (NG).MethodsDuring a 5.5-year period, 56 consecutive patients with a NG underwent TAE. In Group A, there were 20 patients with a solitary/dominant 5–11-cm nodule, and in Group B, there were 36 patients with numerous nodules. Of the 56 patients, 47 (84%) had a retrosternal goiter and 25 had hyperthyroidism. In all patients, clinical and radiological evaluations were made at baseline and 6 months after TAE, and these parameters were statistically compared.ResultsIn 56 patients, 145 of the 146 thyroid arteries were successfully embolized. The 30-day mortality rate was 1.8%. Minor and major complications occurred in 25 and 2 patients, respectively. Six months after the TAE, the mean nodule volume was reduced from 80.2 mL to 25.0 mL, the mean thyroid volume was reduced from 147.0 mL to 62.6 mL, and the mean intrathoracic extension was reduced from 31.7 mm to 15.9 mm (P < .001). Of the 22 patients with non–Graves hyperthyroidism, 19 (86%) became euthyroid. The mean thyroid-related patient-reported outcome scores improved from 155.4 to 70.4 (P < .001). Of the 51 patients, 50 (98%) declared that they would recommend TAE to other patients with NG.ConclusionsTAE is safe and effective for the treatment of NG, with a significant volume reduction of the nodule(s) and thyroid gland.  相似文献   
46.
Acute Coma     
《Neurologic Clinics》2021,39(2):257-272
  相似文献   
47.
The effect of tobacco smoking on foot and ankle procedures is likely to be more pronounced when compared to other orthopaedic surgery. This is due to the peripheral nature of the vasculature involved. This paper reviews the current clinical evidence on the effects of smoking foot and ankle surgery. In the trauma setting, the evidence suggests that wound complications and non-unions are significantly higher in the smoking population. In the elective setting there is a significantly increased risk of non-union in ankle and hindfoot arthrodeses in smokers. In the setting of diabetes, ulceration rate in smokers is higher and there may be a higher risk of amputation.  相似文献   
48.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
49.
The teaching and clinical practice of professor Yves Pélicier contributed to the international development of a psychiatry centered on the whole of the person in a humanist approach. The theoretical developments were marked by the authenticity of the practice of the therapist and its deep sense of the human being thus truly founding a School.  相似文献   
50.
《Clinical neurophysiology》2021,132(9):2003-2011
ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons.  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