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   1160917篇
  免费   85537篇
  国内免费   2761篇
耳鼻咽喉   15700篇
儿科学   40104篇
妇产科学   32628篇
基础医学   169876篇
口腔科学   34012篇
临床医学   104780篇
内科学   222283篇
皮肤病学   27295篇
神经病学   96142篇
特种医学   45512篇
外国民族医学   305篇
外科学   173655篇
综合类   24415篇
一般理论   438篇
预防医学   87950篇
眼科学   26119篇
药学   83262篇
  3篇
中国医学   2292篇
肿瘤学   62444篇
  2019年   9183篇
  2018年   14071篇
  2017年   11200篇
  2016年   13235篇
  2015年   13853篇
  2014年   18165篇
  2013年   28641篇
  2012年   37301篇
  2011年   40258篇
  2010年   23783篇
  2009年   21220篇
  2008年   38192篇
  2007年   40464篇
  2006年   40441篇
  2005年   39032篇
  2004年   37814篇
  2003年   36684篇
  2002年   35450篇
  2001年   52531篇
  2000年   54983篇
  1999年   44322篇
  1998年   12900篇
  1997年   11532篇
  1996年   11311篇
  1995年   10734篇
  1994年   10034篇
  1993年   9338篇
  1992年   33402篇
  1991年   32515篇
  1990年   32079篇
  1989年   31008篇
  1988年   28142篇
  1987年   28351篇
  1986年   26364篇
  1985年   25634篇
  1984年   19431篇
  1983年   16367篇
  1982年   10079篇
  1981年   9124篇
  1979年   17627篇
  1978年   12867篇
  1977年   10997篇
  1976年   10356篇
  1975年   10782篇
  1974年   12916篇
  1973年   12398篇
  1972年   11312篇
  1971年   10570篇
  1970年   9804篇
  1969年   9100篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
32.
33.
Sorsby fundus dystrophy (SFD), an autosomal dominant, fully penetrant, degenerative disease of the macula, is manifested by symptoms of night blindness or sudden loss of visual acuity, usually in the third to fourth decades of life due to choroidal neovascularization (CNV). SFD is caused by specific mutations in the Tissue Inhibitor of Metalloproteinase-3, (TIMP3) gene. The predominant histo-pathological feature in the eyes of patients with SFD are confluent 20–30 m thick, amorphous deposits found between the basement membrane of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. SFD is a rare disease but it has generated significant interest because it closely resembles the exudative or “wet” form of the more common age-related macular degeneration (AMD). In addition, in both SFD and AMD donor eyes, sub-retinal deposits have been shown to accumulate TIMP3 protein. Understanding the molecular functions of wild-type and mutant TIMP3 will provide significant insights into the patho-physiology of SFD and perhaps AMD. This review summarizes the current knowledge on TIMP3 and how mutations in TIMP3 cause SFD to provide insights into how we can study this disease going forward. Findings from these studies could have potential therapeutic implications for both SFD and AMD.  相似文献   
34.
We report two British cases of liver abscess, due to Klebsiella pneumoniae and associated with synchronous infection elsewhere, which required liver resection for definitive treatment. They illustrate the geographic spread of aggressive K pneumoniae liver infection and demonstrate the importance of early aggressive treatment.  相似文献   
35.
36.
Henna, derived from a combination of natural leaves and coloring additives, is a common decorative dye traditionally used in many Islamic religious celebrations. Para‐phenylenediamine (PPD), a major component of black henna tattoo, is a strong sensitizer and common allergen. We report a case of severe connubial allergic contact dermatitis after black henna heterotransfer in a girl.  相似文献   
37.
Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (Pacnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.  相似文献   
38.
39.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
40.
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