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   180469篇
  免费   1527篇
  国内免费   5篇
耳鼻咽喉   1209篇
儿科学   6772篇
妇产科学   3163篇
基础医学   17217篇
口腔科学   1739篇
临床医学   13001篇
内科学   31491篇
皮肤病学   784篇
神经病学   16808篇
特种医学   9113篇
外科学   29518篇
综合类   2535篇
一般理论   4篇
预防医学   18634篇
眼科学   2783篇
药学   9903篇
中国医学   655篇
肿瘤学   16672篇
  2021年   98篇
  2019年   126篇
  2018年   22029篇
  2017年   17430篇
  2016年   19598篇
  2015年   983篇
  2014年   904篇
  2013年   947篇
  2012年   7140篇
  2011年   21247篇
  2010年   18927篇
  2009年   11606篇
  2008年   19654篇
  2007年   21855篇
  2006年   704篇
  2005年   2315篇
  2004年   3535篇
  2003年   4477篇
  2002年   2614篇
  2001年   451篇
  2000年   596篇
  1999年   311篇
  1998年   259篇
  1997年   241篇
  1996年   145篇
  1995年   157篇
  1994年   142篇
  1993年   105篇
  1992年   152篇
  1991年   215篇
  1990年   253篇
  1989年   210篇
  1988年   183篇
  1987年   173篇
  1986年   148篇
  1985年   143篇
  1984年   117篇
  1983年   110篇
  1982年   92篇
  1980年   77篇
  1979年   83篇
  1978年   67篇
  1974年   90篇
  1973年   73篇
  1971年   54篇
  1970年   64篇
  1969年   75篇
  1968年   54篇
  1938年   65篇
  1932年   60篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
Abstract Surgical treatment of proximal humeral fractures still remains a challenge. This is primarily due to the fact that sufficient implant fixation in humeral head fractures is often not achieved due to substantial bone tissue loss with increasing age. In the last few years the locking plates and locking nails have been introduced into clinical practice with varying results. The biomechanical studies have focused on locking plate osteosynthesis as well. The following paper focuses on bone quality, biomechanical studies and biology of proper osteosynthesis and reviews the most recent literature.  相似文献   
23.
24.
25.
26.
Haemangiomas are the most common tumours of infancy. They typically proliferate then involute with considerable variation as regards to their rates of proliferation and involution. Haemangioma of the nasal tip is a lesion of special characteristics. During proliferation, it expands, contracts and deviates the nasal cartilages. Particularly, it regresses slowly and frequently involutes incompletely. That is why excision of the lesion is frequently suggested. The present study was conducted to evaluate open rhinoplasty after initial non-excision treatment modalities namely, intra-lesional corticosteroid injections and laser treatment, as a protocol of treatment for nasal tip haemangiomas. Twelve patients with nasal tip haemangiomas were included in the present study. Patients of both sexes, of different ages, with deep and mixed haemangiomas were studied. Disfigurement was the constant presenting symptom. Initial non-excision treatment reported different responses as denoted by the regression of the lesions’ size. Haemangiomas constantly extended between the medial crura of the alar cartilages as noted by the constant widening of the columella pre-operatively and the obvious separation of the nasal cartilages intra-operatively. This separation was constantly found to require approximation by sutures. The results of the present study concluded that whenever an early presentation with nasal tip haemangioma could be established, initial non-excision treatment followed by open rhinoplasty could be a useful protocol of treatment. Within the limitations of the present study, this protocol could achieve an early, safe and effective treatment for nasal tip haemangiomas with provisionally acceptable cosmetic outcomes so far.  相似文献   
27.
This study investigates whether tissue recoil or patient intrinsic factors influence the final position of the nipple areola complex (NAC) after reduction mammoplasty. The age, pre-operative ptosis, BMI and weight of the tissue resected were recorded as patient intrinsic factors in 37 patients undergoing reduction mammoplasty. The “spring-back” value was defined as the distance from the sternal notch to a nipple landmark on the breast meridian with the patient sitting up, minus the same measurement repeated with the patient recumbent to eliminate the pull of gravity on the breast. Spring back was measured pre-operatively for the nipple and nipple mark then post-operative for the nipple. The difference in centimeters between the final post-operative distance from the sternal notch to the nipple and the level intended by the pre-operative nipple mark was termed the “judgment error.” The final position of the post-operative nipple and the judgment error was compared to the spring-back values and patient intrinsic factors. Pre-operative ptosis was statistically related to increasing patient BMI and mass of tissue resected per breast. Pre-operative spring-back values for the nipple increased with increasing ptosis, BMI and decreasing age. Spring-back values were greater in the lower pole of the breast than in the upper pole. The final position of the nipple was higher than the pre-operative mark in 65% of cases, lower in 8% and as marked in 27% of cases. The post-operative NAC was, on average, 0.6 cm higher than planned pre-operatively. The post-operative distance from the sternal notch to the nipple increased with increasing pre-operative ptosis, mass of breast tissue resected per breast and all three spring-back values. The difference between the level of the pre-operative mark and the final nipple position showed a weak correlation with post-operative spring-back values. The parameters of ptosis, BMI, weight of tissue resected per breast and pre-operative nipple spring back reflect body habitus and breast size. Spring-back values vary between the upper and lower pole of the breast. The final NAC position was higher than that intended at pre-operative marking in the majority of cases. The surgeon instinctively marks the nipple lower in patients with greater pre-operative ptosis and in whom a larger resection is anticipated. Judgment error did not relate to intrinsic factors nor to pre-operative spring-back values; hence, these parameters cannot be applied as predictive tools for more accurate pre-operative marking of the nipple position. This study suggests that the pre-operative nipple mark should be placed, with the patient sitting up, at least 23 cm from the sternal notch and 0.6 cm lower than the final position estimated using the inframammary crease as a landmark. An invited commentary on this paper is available at .  相似文献   
28.
29.
Conclusions  Noninvasive imaging of neurohumoral upregulation in remodeled myocardium suggests that an imaging strategy can be developed for predicting the rate of remodeling and likelihood of HF development. This should allow a more judicious use of neurohumoral antagonists especially in subjects who do not have manifest HF.74 In others specific targeted imaging may allow timely selection of individualized treatment strategies and ensure optimization of therapeutic intervention. Similar to ACE and AII receptors, multiple other targets in the hormonal cascades can identify the likelihood of adverse and favorable remodeling.74  相似文献   
30.
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