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   3471786篇
  免费   250795篇
  国内免费   8861篇
耳鼻咽喉   49183篇
儿科学   113609篇
妇产科学   96660篇
基础医学   496413篇
口腔科学   97033篇
临床医学   313531篇
内科学   679864篇
皮肤病学   82358篇
神经病学   284647篇
特种医学   135241篇
外国民族医学   952篇
外科学   517388篇
综合类   73138篇
现状与发展   5篇
一般理论   1295篇
预防医学   269249篇
眼科学   79458篇
药学   250612篇
  11篇
中国医学   6685篇
肿瘤学   184110篇
  2019年   26174篇
  2018年   37034篇
  2017年   28443篇
  2016年   32785篇
  2015年   38860篇
  2014年   53384篇
  2013年   80156篇
  2012年   104002篇
  2011年   110130篇
  2010年   67384篇
  2009年   64750篇
  2008年   103080篇
  2007年   109438篇
  2006年   111518篇
  2005年   107057篇
  2004年   103069篇
  2003年   98520篇
  2002年   94124篇
  2001年   162459篇
  2000年   166806篇
  1999年   140477篇
  1998年   41085篇
  1997年   36599篇
  1996年   37288篇
  1995年   36363篇
  1994年   33712篇
  1993年   31543篇
  1992年   111377篇
  1991年   107453篇
  1990年   104010篇
  1989年   100076篇
  1988年   91940篇
  1987年   90357篇
  1986年   84998篇
  1985年   81124篇
  1984年   61008篇
  1983年   51569篇
  1982年   30955篇
  1981年   27803篇
  1979年   54468篇
  1978年   38927篇
  1977年   32805篇
  1976年   30444篇
  1975年   32602篇
  1974年   38593篇
  1973年   36879篇
  1972年   34396篇
  1971年   31901篇
  1970年   29353篇
  1969年   28081篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.

Background

Chronic limb-threatening ischemia (CLTI), defined as ischemic rest pain or tissue loss secondary to arterial insufficiency, is caused by multilevel arterial disease with frequent, severe infrageniculate disease. The rise in CLTI is in part the result of increasing worldwide prevalence of diabetes, renal insufficiency, and advanced aging of the population. The aim of this study was to compare a bypass-first with an endovascular-first revascularization strategy in patients with CLTI due to infrageniculate arterial disease.

Methods

We reviewed the American College of Surgeons National Surgical Quality Improvement Program targeted lower extremity revascularization database from 2012 to 2015 to identify patients with CLTI and isolated infrageniculate arterial disease who underwent primary infrageniculate bypass or endovascular intervention. We excluded patients with a history of ipsilateral revascularization and proximal interventions. The end points were major adverse limb event (MALE), major adverse cardiovascular event (MACE), amputation at 30 days, reintervention, patency, and mortality. Multivariable logistic regression was used to determine the association of a bypass-first or an endovascular-first intervention with outcomes.

Results

There were 1355 CLTI patients undergoing first-time revascularization to the infrageniculate arteries (821 endovascular-first revascularizations and 534 bypass-first revascularizations) identified. There was no significant difference in adjusted rate of 30-day MALE in the bypass-first vs endovascular-first revascularization cohort (9% vs 11.2%; odds ratio [OR], 0.73; 95% confidence interval [CI], 0.50-1.08). However, the incidence of transtibial or proximal amputation was lower in the bypass-first cohort (4.3% vs 7.4%; OR, 0.60; CI, 0.36-0.98). Patients with bypass-first revascularization had higher wound complication rates (9.7% vs 3.7%; OR, 2.75; CI, 1.71-4.42) compared with patients in the endovascular-first cohort. Compared with the endovascular-first cohort, the incidence of 30-day MACE was significantly higher in bypass-first patients (6.9% vs 2.6%; adjusted OR, 3.88; CI, 2.18-6.88), and 30-day mortality rates were 3.23% vs 1.8% (adjusted OR, 2.77; CI, 1.26-6.11). There was no difference in 30-day untreated loss of patency, reintervention of treated arterial segment, readmissions, and reoperations between the two cohorts. In subgroup analysis after exclusion of dialysis patients, there was also no significant difference in MALE or amputation between the bypass-first and endovascular-first cohorts.

Conclusions

CLTI patients with isolated infrageniculate arterial disease treated by a bypass-first approach have a significantly lower 30-day amputation. However, this benefit was not observed when dialysis patients were excluded. The bypass-first cohort had a higher incidence of MACE compared with an endovascular-first strategy. These results reaffirm the need for randomized controlled trials, such as the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL-2) trial and Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI), to provide level 1 evidence for the role of endovascular-first vs bypass-first revascularization strategies in the treatment of this population of challenging patients.  相似文献   
33.
Chronic transplant dysfunction is a complex dynamic pathogenic process. Clinically, a decrease in glomerular filtration rate (GFR) becomes apparent leading to chronic renal insufficiency and dialysis or death from cardiovascular events. Chronic transplant dysfunction can develop into a chronic alIograft nephropathy (CAN) as a specific entity with dynamic progression. CAN includes a collection of immunologic and non-immunologic factors, rejection, ischemia time, donor and recipient characteristics and toxicity of calcineurin inhibitors. Despite improvements in immunosuppression, the long-range prognosis of renal allografts has not improved. Whether modern immunosuppressive concepts with reduction or avoidance of calcineurin inhibitors and a therapy based on antimetabolites, such as mycophenolate or mTOR-inhibitors could lead to a prolongation of transplant survival, remains to be seen.  相似文献   
34.
35.
Zusammenfassung In Deutschland leiden 25% der über 70-Jährigen unter einem Diabetes mellitus. Biologisch ältere, multimorbide und in ihren Funktionen beeinträchtigte geriatrische Patienten benötigen spezielle Vorgehensweisen bei Zielplanung, Allgemeinmaßnahmen und Pharmakotherapie. Auf der Basis der vorhandenen Leitlinien werden gesicherte Erkenntnisse dargestellt und Empfehlungen zu den Besonderheiten der Therapie des geriatrischen Diabetespatienten gegeben. Besonderes Augenmerk liegt dabei auf der Interaktion von geriatrischen Syndromen und Diabetes sowie der Verbesserung der Lebensqualität.  相似文献   
36.
We report the case of a littoral‐cell angioma of the spleen, a recently described benign vascular tumour, whose imaging and pathological characteristics have been discussed only by a few authors. The diagnosis was made after elective splenectomy. The CT images, scintigraphy and histological specimens are presented, and differential diagnoses discussed.  相似文献   
37.
38.
39.
40.
Conclusion  Several quality-control measures take place before (patient and camera preparation) and during SPECT acquisition to achieve high-quality images. Not uncommonly, technologists and physicians are left with suboptimal images that have to be addressed to reach the “right answer” for patient diagnosis and hence management. In many cases patients may be reimaged, especially if the problem is detected early, but in other cases either the patient has left the nuclear laboratory or there is an inevitable problem that, even with reimaging, will not be resolved. In these situations the technologist and physician have to seek the available techniques to obtain the best images possible. These resources are discussed in this issue as an aid in quality control to obtain the best possible images.  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