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   7599篇
  免费   460篇
  国内免费   61篇
耳鼻咽喉   137篇
儿科学   118篇
妇产科学   63篇
基础医学   344篇
口腔科学   172篇
临床医学   975篇
内科学   662篇
皮肤病学   84篇
神经病学   414篇
特种医学   115篇
外国民族医学   1篇
外科学   609篇
综合类   1119篇
预防医学   2036篇
眼科学   48篇
药学   748篇
  29篇
中国医学   304篇
肿瘤学   142篇
  2024年   12篇
  2023年   166篇
  2022年   225篇
  2021年   386篇
  2020年   419篇
  2019年   349篇
  2018年   313篇
  2017年   328篇
  2016年   248篇
  2015年   285篇
  2014年   640篇
  2013年   699篇
  2012年   590篇
  2011年   555篇
  2010年   441篇
  2009年   369篇
  2008年   312篇
  2007年   307篇
  2006年   257篇
  2005年   202篇
  2004年   155篇
  2003年   136篇
  2002年   87篇
  2001年   90篇
  2000年   67篇
  1999年   60篇
  1998年   35篇
  1997年   33篇
  1996年   48篇
  1995年   42篇
  1994年   26篇
  1993年   23篇
  1992年   15篇
  1991年   12篇
  1990年   14篇
  1989年   15篇
  1988年   19篇
  1987年   10篇
  1986年   5篇
  1985年   17篇
  1984年   21篇
  1983年   14篇
  1982年   14篇
  1981年   9篇
  1980年   10篇
  1979年   9篇
  1978年   7篇
  1977年   5篇
  1974年   5篇
  1973年   4篇
排序方式: 共有8120条查询结果,搜索用时 171 毫秒
41.
目的 在预防医学专业本科学生中开展开放性实验,探索实验教学改革方法,提升学生的专业素养和科研能力。方法 针对预防医学专业大四学生,以职业卫生与职业医学实验课程为抓手,进行开放实验教学,然后用问卷调查评估实验效果。2016级预防医学专业学生147人为对照组,开展常规验证性实验;2017级预防医学专业学生176人为试验组,开展开放性实验。从综合考评成绩、教师自评、学生满意度调查3个方面进行评价。采用SPSS 22.0软件进行独立样本t检验、卡方检验。结果 试验组和对照组学生的职业卫生与职业医学期末考试理论成绩是[(84.37±10.45)分 vs. (81.44±9.22)分](t=2.68,P=0.008),实验技能成绩是[(93.66±3.89)分 vs. (88.41±5.67)分](t=9.51,P<0.001),两组相比,试验组高于对照组,差异有统计学意义。问卷调查显示,试验组学生对于学时安排(χ2=8.31,P=0.004)、小组协作(χ2=21.10,P<0.001)、考核形式(χ2=7.92,P=0.005)、提升科研论文撰写能力(χ2=17.56,P<0.001)、提高实践技能(χ2=11.70,P=0.001)、逻辑思维和语言组织表达能力(χ2=10.33,P=0.001)的满意度更高。学生认为开放实验有助于培养学生创新思维和能力,但是对于就业优势的培养作用有限。学生认为开设专业课的开放性实验具有充分必要性。结论 在预防医学专业学生中开展开放性实验对于学生提升专业素养、增强实践和科研能力是有益的。  相似文献   
42.
针对目前我国预防医学人才培养过程中存在的教育模式陈旧、理论/实践脱节、缺乏多维度融合等的不足,本文提出结合大学生研究训练计划进行预防医学本科生培养模式改革的尝试。但该项改革在实施过程中暴露出许多问题,效果尚不尽如人意,尤其是在应急管理和解决实际问题方面。为了培养出符合时代需求的预防医学实用型人才,基于大学生研究训练计划的预防医学人才培养模式的实施,仍需包括立项、指导和评价等多个方面的长足努力才能保障培养效果。  相似文献   
43.
目的评价重组人干扰素α-2b鼻腔喷雾剂对恒河猴感染SARS-CoV的预防治疗作用。方法采用鼻腔喷雾法(剂量为60万单位/鼻孔)研究了重组人干扰素α-2b鼻腔喷雾剂对感染SARS-CoV的恒河猴预防治疗效果。结果试验组(5只)和对照组(5只)相同时间检测的咽拭子等标本中,Real-time PCR检测和病毒分离均未检出病毒。攻毒后病毒导致机体产生的中和抗体和IgG抗体的反应也较对照组弱。血液学指标检测结果表明试验组动物攻毒后各项指标较试验前比较没有显著性改变;病理结果显示试验组2只恒河猴肺组织形态基本正常,其余3只猴有肺间质性炎,表现肺间隔增厚、单核样细胞为主的炎细胞浸润,其中1只增厚的肺间隔有局灶相互融合,这3只猴肺部病变与对照组的病变表现相似,且病变累及范围较对照组小;其他各受检脏器均未见明显异常。结论重组人干扰素α-2b鼻腔喷雾剂可以有效阻断或减弱SARS-CoV对恒河猴的感染。  相似文献   
44.
Preventive Measures in Mite Asthma   总被引:1,自引:3,他引:1  
Jens  Korsgaard 《Allergy》1983,38(2):93-102
To evaluate the effect of preventive measures 46 patients, all allergic to house-dust mites (Dermatophagoides spp.), were randomly allocated to a study and a control group. According to the patients' subjective recordings of symptom score and use of medicine, compared with the control group, the study group had improved. There was, however, no improvement when comparing the objective recordings of morning and evening peak flow and use of medicine, and it is concluded that the preventive measures in this programme are not very effective for patients allergic to house-dust mites. The reduction in indoor humidity in the study group was limited and, as a high indoor humidity is the cause of huge populations of house-dust mites in homes, it is emphasized that future programmes of preventive measures should focus more on damp problems, particularly those related to bad housing construction.  相似文献   
45.
Cardiac responses to non-signal stimuli and to signal stimuli in a vigilance task were examined in children born with congenital heart defects (CHD), and in normal and attention deficit disordered (ADD) subjects. Overall task performance was lower in subjects with heart defects and in the ADD group. Cardiac measures revealed that normal children displayed significantly larger heart rate deceleration to the target stimuli than did either of the clinical groups. Moreover, although no group differences were observed in the cardiac response to non-signal auditory stimuli, exaggerated heart rate deceleration was observed to vibrotactile stimuli in both the clinical groups. Regression analyses revealed that the magnitude of the cardiac response to somatosensory stimuli was predictive of task performance (both within and between subject groups), with larger responses associated with higher error rates and lower perceptual sensitivity. Results were suggestive of a predictive relationship between somatosensory reactivity and neuropsychological maturation.  相似文献   
46.
Because prepared learning has been defined in terms of response acquisition in spite of degraded input, it was expected that differences in resistance to extinction between skin conductance responses conditioned to potentially phobic and neutral stimuli would increase with increased interstimulus interval (ISI) and be larger with a trace than with a delay conditioning paradigm. Twelve groups with 10 subjects each were observed in a differential conditioning experiment manipulating ISI (2, 8, or 16 sec), paradigm (delay versus trace), and fear-relevance of the conditioned stimulus (potentially phobic versus neutral). The results showed highly reliable resistance to extinction of first-interval anticipatory responses to phobic stimuli, and no resistance to extinction of the corresponding responses to the neutral stimuli. This difference did not interact either with the ISI or the paradigm factor. Thus, although underscoring the reliability of the difference in conditioning to potentially phobic and neutral stimuli, the results did not support the specific hypothesis of conditioning to phobic stimuli as being less dependent on the ISI parameters than conditioning to neutral stimuli.  相似文献   
47.
We compared the accuracy of P300 latency estimates obtained with different procedures under several simulated signal and noise conditions. Both preparatory and signal detection techniques were used. Preparatory techniques included frequency filters and spatial filters (single electrode selection and Vector filter). Signal detection techniques included peak-picking, cross-correlation, and Woody filter. Accuracy in the latency estimation increased exponentially as a function of the signal-to-noise ratio. Both Woody filter and cross-correlation provided better estimates than peak-picking, although this advantage was reduced by frequency filtering. For all signal detection techniques, Vector filter provided better estimates than single electrode selection. Large component overlap impaired the accuracy of the estimates obtained with both single electrode selection and Vector filter, but with Vector filter impairment occurred only when the overlapping component had a scalp distribution that was similar to the scalp distribution of the signal component. The effects of varying noise characteristics, P300 duration and latency, and the parameters of Vector filter were also investigated.  相似文献   
48.
Summary An investigation of the staff of a car assembly plant (3,351 persons) revealed a similarity between the change in relative body weight and diastolic blood pressure with age. There is a good temporal correlation between the course of alcohol consumption during life and the change of the relative body weight. German women had significantly less blood pressure for the same relative body weight than German men, and foreign employees had lower blood pressure than Germans In both cases the main cause is the difference in alcohol consumption. Besides obesity and hereditary factors, alcohol is the main cause of essential hypertension today. Epidemiological and experimental data indicate that there are two ways from alcohol to high blood pressure, a more direct one and an indirect one via obesity. Alcohol causes obesity via a change in metabolism (hyperinsulinism) rather than by higher caloric intake. In both ways alcohol is an important cause of stroke. To reduce body weight and blood pressure, a reduction of alcohol consumption should be recommended in addition to reduced caloric intake and increased physical activity as means of preventive neurology.  相似文献   
49.
Minimal interventions for weight control: a cost-effective alternative   总被引:2,自引:0,他引:2  
Two studies were conducted to evaluate simpler, less intensive interventions for weight control which presumably would be more cost-effective and efficient than a "full-length" behavioral treatment program. In Study 1, participants in a minimal intervention (MI1) program who attended no regularly scheduled meetings and initially only received three simple verbal instructions about how to lose weight, lost an average of 11.1 lb. by 7-month follow-up. Subjects in three variations of a shortened, less intensive, 6-week behavioral weight loss program lost 7.8, 6.5 and 6.3 lb. but did not significantly differ from MI1 subjects in the amount of weight lost. In Study 2, MI2 subjects lost 5.5 lb. compared to subjects in two variations of a full-length program who lost 8.1 and 11.1 lb. by 6-month follow-up. Again, none of the groups significantly differed from each other in the amount lost. It was concluded that a minimal intervention program seems to produce weight loss and to be a cost-effective and efficient method for some subjects. The difference between the two minimal intervention programs may be related to the payment of a monetary deposit; a model for future research was presented to investigate simpler, less intensive interventions in combination with more complex ones in a "stepped-care" fashion.  相似文献   
50.
目的 系统评价PBL教学模式对预防医学生课程教学效果的影响。方法 检索PubMed、CNKI、WanFang Data、CBM和VIP数据库,搜集PBL应用于预防医学生教学的RCT研究,采用R软件(3.6.2版本)进行Meta分析。结果 共纳入23篇文献,包括2 108例研究对象。Meta分析结果显示,PBL组预防医学生的理论成绩[ SMD =1.13,95% CI (0.65,1.60)]、实践操作成绩 [ SMD =1.27,95% CI (0.91,1.63)]、教学满意度[ RR =1.33,95% CI (1.17,1.52)]、学习兴趣[ RR =1.61,95% CI (1.37,1.89)]、自主学习能力 [ RR =1.63, 95% CI (1.39,1.92)]、团队协作能力[ RR =2.11,95% CI (1.54,2.89)]、解决问题能力[ RR =1.58,95% CI (1.36,1.83)]均显著优于LBL组。亚组分析结果显示PBL联合教学组预防医学生的理论成绩[ SMD =1.27,95% CI (0.46,2.09)]、实践操作成绩[ SMD =1.39,95% CI (0.82,1.96)]、团队协作能力[ RR =2.27,95% CI (1.41,3.64)]均优于单独使用PBL组,PBL在毒理学课程中对提高预防医学生的理论成绩[ SMD =1.44,95% CI (1.10,1.79)]和实践操作成绩[ SMD =1.16,95% CI (0.74,1.59)]效果均较为显著。结论 PBL对预防医学生的教学效果具有显著影响;PBL联合教学比单独使用PBL的教学效果更显著;未来需纳入更多严谨的试验设计来验证其应用效果。  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