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   2356篇
  免费   228篇
  国内免费   11篇
耳鼻咽喉   37篇
儿科学   113篇
妇产科学   25篇
基础医学   278篇
口腔科学   54篇
临床医学   284篇
内科学   547篇
皮肤病学   37篇
神经病学   101篇
特种医学   391篇
外科学   141篇
综合类   32篇
一般理论   1篇
预防医学   231篇
眼科学   27篇
药学   188篇
中国医学   13篇
肿瘤学   95篇
  2021年   24篇
  2019年   19篇
  2018年   31篇
  2017年   16篇
  2016年   23篇
  2015年   32篇
  2014年   33篇
  2013年   55篇
  2012年   55篇
  2011年   65篇
  2010年   64篇
  2009年   53篇
  2008年   75篇
  2007年   127篇
  2006年   116篇
  2005年   99篇
  2004年   100篇
  2003年   89篇
  2002年   82篇
  2001年   73篇
  2000年   80篇
  1999年   78篇
  1998年   110篇
  1997年   79篇
  1996年   93篇
  1995年   65篇
  1994年   62篇
  1993年   63篇
  1992年   30篇
  1991年   26篇
  1990年   34篇
  1989年   60篇
  1988年   42篇
  1987年   56篇
  1986年   46篇
  1985年   47篇
  1984年   42篇
  1983年   32篇
  1982年   31篇
  1981年   31篇
  1980年   34篇
  1979年   26篇
  1978年   27篇
  1977年   29篇
  1976年   25篇
  1975年   19篇
  1974年   9篇
  1972年   8篇
  1971年   9篇
  1969年   9篇
排序方式: 共有2595条查询结果,搜索用时 15 毫秒
1.
Needle-localized breast biopsy: why do we fail?   总被引:10,自引:0,他引:10  
Jackman  RJ; Marzoni  FA  Jr 《Radiology》1997,204(3):677
  相似文献   
2.
3.
4.
This paper reports student (n = 180) feedback on the role-play teaching methodology used in behavioural sciences teaching at The School of Dentistry in Birmingham (UK). The feedback received on this well-established (since 1995) educational programme was collected via questionnaire (100% response rate), requiring Likert scale and free text responses. Generally students reported that they had enjoyed and valued the session. Over two-thirds (69.7%) of students rated the role-players as 'very real' and over three-quarters (78.9%) rated their feedback as 'very fair'. The data collected from this study will inform future curriculum development. Student feedback was very positive and demonstrated that the cohort (86% of all students studying in years 1, 2 and 3) found the use of professional role-players involved in behavioural sciences teaching to be both acceptable and valuable.  相似文献   
5.
6.
OBJECTIVE--To determine the association between measures of socioeconomic status and reported back pain in a national sample survey of the adult population of Britain. DESIGN--Secondary analysis of a cross sectional interview survey (the Health and Lifestyle Survey). SETTING--Households in England, Wales, and Scotland. SUBJECTS--Those 9003 adults aged 18 years and above who agreed to an interview, from a study base of 12,254 private households that had been identified in a three stage sampling procedure based on electoral registers. Subjects who reported back pain in the month before interview were compared with all those who stated they had not experienced this symptom. MEASURES AND RESULTS--Women whose households were in the lowest income category were more likely to report back pain than those in the highest income group (odds ratio 1.6, 95% confidence interval (CI) 1.2, 2.1). In addition, women with no formal educational qualification were more likely to report back pain than women who had a qualification (odds ratio 1.5, 95% CI 1.0, 2.1). These associations were not explained by smoking, obesity, and coexistent depressive symptoms. In men the only socioeconomic link with back pain seemed to be manual occupation. CONCLUSIONS--These findings confirm the higher burden of back pain in the socially disadvantaged, but suggest that this cannot yet be explained by known risk factors for back trouble.  相似文献   
7.
荧光原位杂交技术分析人结肠菌群方法研究   总被引:2,自引:0,他引:2  
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。  相似文献   
8.
9.
10.
Six of 12 children with Down syndrome (DS) tested by means of long-term tape-recordings of oxygen saturation, breathing movements and expired CO2 were found to have previously undetected and severe upper airway obstruction during sleep. In five cases the obstruction occurred in the pharynx and in the sixth it was due to bilateral choanal stenosis. When compared with age-matched controls, overnight tape-recordings showed episodes of abnormal arterial hypoxaemia and an abnormally elevated end-tidal CO2. Episodes of obstruction were most marked during sleep associated with a non-regular breathing pattern. Abnormal episodes of hypoxaemia were associated with continued breathing movements. Sometimes there was no airflow (complete obstruction); at other times airflow continued normally or was reduced in amplitude (partial obstruction). During episodes of partial or complete airway obstruction the inspiratory waveform showed a characteristic shape. These results show sleep-related upper airway obstruction to be an often undetected complication of DS and all necessary measures should be taken to overcome the obstruction when it reaches the stage of producing abnormal hypoxaemia. Choanal dilatation and tracheostomy were successful in treating two of the children. Tonsillectomy and adenoidectomy were successful for one child, but only of marginal benefit for two others.  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