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   19226篇
  免费   1258篇
  国内免费   81篇
耳鼻咽喉   172篇
儿科学   500篇
妇产科学   392篇
基础医学   2227篇
口腔科学   338篇
临床医学   1560篇
内科学   4039篇
皮肤病学   236篇
神经病学   1061篇
特种医学   528篇
外科学   3372篇
综合类   672篇
一般理论   18篇
预防医学   1445篇
眼科学   529篇
药学   1959篇
中国医学   234篇
肿瘤学   1283篇
  2023年   150篇
  2022年   271篇
  2021年   676篇
  2020年   437篇
  2019年   548篇
  2018年   661篇
  2017年   476篇
  2016年   378篇
  2015年   528篇
  2014年   738篇
  2013年   924篇
  2012年   1344篇
  2011年   1339篇
  2010年   777篇
  2009年   588篇
  2008年   1047篇
  2007年   1059篇
  2006年   962篇
  2005年   902篇
  2004年   816篇
  2003年   748篇
  2002年   643篇
  2001年   565篇
  2000年   501篇
  1999年   414篇
  1998年   148篇
  1997年   120篇
  1996年   119篇
  1995年   121篇
  1994年   68篇
  1993年   81篇
  1992年   208篇
  1991年   190篇
  1990年   167篇
  1989年   174篇
  1988年   138篇
  1987年   155篇
  1986年   126篇
  1985年   135篇
  1984年   110篇
  1983年   87篇
  1982年   60篇
  1981年   60篇
  1979年   97篇
  1978年   64篇
  1977年   65篇
  1975年   61篇
  1974年   53篇
  1973年   56篇
  1972年   50篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
71.
72.
73.
74.
将药物及高分子材料溶于乙醇后边搅拌边加入非溶剂制成布洛芬-聚丙烯酸树脂Ⅱ共沉淀物。通过A、B两种方法并以不同的药物-聚丙烯酸树脂Ⅱ比例制成了共沉淀物,再以这些共沉淀物直接压片制成骨架片。通过差热分析(DSC)、扫描电镜(DSC)及红外光谱(IR)研究了共沉淀物的性质。研究主要集中在处方中高分子材料所占的比例,溶出介质的pH及制备共沉淀物的方法对布洛芬从骨架中释放的影响。体外溶出实验分别在不同的pH条件下进行。处方研究表明随着聚丙烯酸树脂Ⅱ用量的增加,药物的释放过程显著延长。另外,增加溶出介质的pH会显著增加药物的累积释放百分数。此外实验还表明以方法B制成的共沉淀物的骨架片中药物的累积释放百分数要高于A法制成的骨架片,然而方法A中制得的骨架片中药物的释放却更接近于线性释放。  相似文献   
75.
76.
OBJECTIVES: To determine the accuracy of self-reported comorbidities compared with medical record review and the clinical and sociodemographic characteristics associated with accuracy of self-reported comorbidities. STUDY DESIGN: We conducted a prospective study of 458 newly diagnosed head and neck cancer patients using self-administered questionnaire and medical chart review data. Overall and itemwise consistency between self-report and chart review was evaluated. Social, clinical, and demographic characteristics of consistent versus inconsistent responders were analyzed. RESULTS: Seventy-four percent of patients had at least one comorbidity. There was good overall consistency between self-report and chart review (kappa = 0.50). Compared with consistent responders, inconsistent responders were found to be older (P < 0.05), have lower sleep (P < 0.05) and physical activity scores (P < 0.05), be more depressed (P < 0.05), and have more severe comorbidities (P < 0.05). CONCLUSIONS AND SIGNIFICANCE: Self-report may be considered as an alternative to chart review for comorbidity assessment in head and neck cancer patients. Younger patients, those with good general health, fewer depressive symptoms, and mild comorbidities, are more likely to give responses consistent with chart review.  相似文献   
77.
Disulfiram, an alcohol antagonistic drug has been on the market since 1949 with 80% bioavailability and an established safety profile. Recently it has been reported as a P-glycoprotein efflux pump modulator. Herein we report its antifungal potential. The MIC50 and MIC90 of disulfiram for yeast isolates is 4 and 8 microg/ml, respectively, and the MIC range is 1-16 micro g/ml for both fluconazole sensitive and resistant strains. Interestingly, disulfiram also showed fungicidal activity on Aspergillus spp. with MIC50 and MIC90 of 2 and 8 microg/ml, respectively.  相似文献   
78.
Tension development in response to direct and indirect electrical stimulation was studied in an isolated phrenic nerve hemidiaphragm preparation of the mouse. β-Endorphin (β-EP) caused an increase in the preparation of the mouse. β-Endorphin (β-EP) caused an increase in the response to low frequency stimulation of the nerve. Upon direct stimulation of the muscle the peptide had no effect. The actions of β-EP were abolished in the presence of the opioid antagonist naloxone and mimicked by β opioid agonists. Upon high frequency stimulation of the nerve, β-EP caused an increase in the initial, maximum, and mean tension. It also prevented the fall in the final tension seen in the control preparations with repeated periods of stimulation. The findings are consistent with β-EP having a role to improve neuromuscular function and deley fatigue, and indicate the possible therapeutic potential of opioid substances in conditions where muscle weakness is present. © John Wiley & Sons, Inc.  相似文献   
79.
80.
After sustaining a free rupture of the intrapericardial ascending aorta secondary to blunt chest trauma, a 27-year-old man underwent successful aortic repair. To our knowledge, this is the first time a patient has ever survived this condition. Pericardial tamponade-together with rapid transport to the hospital and an aggressive surgical approach-was a key to the recovery of effective cardiac function and successful aortic repair. Although the patient succumbed to complications 74 days after surgery, this case illustrates the possibility of longterm survival after free rupture of the ascending aorta. The following report emphasizes the technical feasibility of controlling the perforated aortic root in such cases.  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