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   1730篇
  免费   76篇
  国内免费   21篇
耳鼻咽喉   57篇
儿科学   26篇
妇产科学   53篇
基础医学   147篇
口腔科学   24篇
临床医学   204篇
内科学   415篇
皮肤病学   13篇
神经病学   96篇
特种医学   81篇
外科学   383篇
综合类   7篇
一般理论   4篇
预防医学   55篇
眼科学   44篇
药学   54篇
中国医学   1篇
肿瘤学   163篇
  2023年   17篇
  2022年   28篇
  2021年   43篇
  2020年   27篇
  2019年   46篇
  2018年   49篇
  2017年   43篇
  2016年   56篇
  2015年   58篇
  2014年   107篇
  2013年   106篇
  2012年   174篇
  2011年   155篇
  2010年   107篇
  2009年   76篇
  2008年   162篇
  2007年   131篇
  2006年   106篇
  2005年   93篇
  2004年   94篇
  2003年   55篇
  2002年   54篇
  2001年   10篇
  2000年   2篇
  1999年   5篇
  1998年   1篇
  1997年   2篇
  1996年   3篇
  1995年   7篇
  1993年   5篇
  1992年   1篇
  1983年   1篇
  1979年   1篇
  1977年   2篇
排序方式: 共有1827条查询结果,搜索用时 15 毫秒
41.
42.
43.
Soft tissue sarcoma(STS) accounts for 1% of all malignant neoplasms in adults. Their diagnosis and management constitute a challenging target. They originate from the mesenchyme, and 50 subtypes with various cytogenetic profiles concerning soft tissue and bones have been recognized. These tumors mainly affect middle-aged adults but may be present at any age. Half of the patients have metastatic disease at the time of diagnosis and require systemic therapy. Tumors above 3-5 cm in size must be sus...  相似文献   
44.
The Trellis Peripheral Infusion System is an over-the-wire 0.035 guidewire compatible device, designed to isolate a region of the peripheral vasculature to allow for lytic drug infusion and dispersion. We used it successfully through a percutaneous approach in two cases of acute thrombosis of a native lower limb artery. The total amount of rt-PA used was 12 and 9 mg, respectively and was delivered through bolus injections obviating the need for a supplementary continuous infusion of the agent. The time for dissolution of thrombus was 45 and 35 minutes, respectively. No complications were observed.  相似文献   
45.
Management of gallstone ileus   总被引:4,自引:0,他引:4  
Background/Purpose. Gallstone ileus is an uncommon complication of cholelithiasis in the elderly with a high morbidity and mortality rate. This study aims to clarify the current surgical management. Methods/results. In a retrospective survey over the past 11 years there were 9 patients with gallstone ileus, all elderly (mean age, 77 years), among 2242 cholecystectomies (0.4%) and 243 operated small intestinal obstructions (3.7%). Urgent laparotomy confirmed gallstone obstruction and a cholecystoduodenal (89%) or cholecystocolonic (11%) fistula. The operation included enterolithotomy alone (3 high-risk cases) or plus fistula repair and cholecystectomy (6 cases). There were 3 postoperative complications including wound dehiscence, wound infection, and obstructive jaundice (morbidity, 37.5%) and 1 death due to myocardial infarction (mortality, 11%). On follow-up (mean, 5 years), 6 patients with cholecystectomy (in 1 case it was performed 2 months after the initial operation) and 1 patient with enterolithotomy alone are well; there was 1 death from an unrelated cause after 1 year. Conclusion. It seems that a one-stage procedure (enterolithotomy plus fistula repair and cholecystectomy), when feasible, should be the first choice. Enterolithotomy alone should be reserved for only unstable and difficult cases.  相似文献   
46.
47.
48.
Hb Adana (HBA2: c.179G>A) is found worldwide but is extremely rare and carriers are asymptomatic, with red cell indices similar to α+-thalassemia (α+-thal) carriers. First line screening tests are unable to detect the unstable hemoglobin (Hb). Coinheritance with the α-thal (–α3.7) deletion is herein presented and the challenges involving genetic counseling of couples carrying the mutations are discussed.  相似文献   
49.
BACKGROUND AND OBJECTIVES: Serum beta(2)-microglobulin (s beta(2)m) is an established prognostic factor for multiple myeloma and non-Hodgkin's lymphoma, but only limited data suggest an adverse prognostic significance for Hodgkin's lymphoma (HL). This study was undertaken to examine the impact of s beta(2)m on the prognosis of patients with HL. DESIGN AND METHODS: s beta(2)m was measured by a radioimmunoassay (upper normal limit 2.4 mg/L), in pretreatment serum samples of 232 patients with HL, who were then treated with ABVD or equivalent regimens with or without radiotherapy. Multivariate survival analysis was based on Cox's proportional hazards model. RESULTS: Main patients' characteristics: median age 30.5 years (14-78); 58% males; 68% nodular sclerosis, 20% mixed cellularity and 12% lymphocyte predominance; 34% B-symptoms; 24% Ann Arbor stage I, 49% II, 18% III and 9% IV. Elevated s beta(2)m levels were detected in 65/232 patients (28%) and correlated with older age (p<0.001), mixed cellularity (p=0.03), B-symptoms (p=0.002), advanced stage (p=0.02), > or = 5 involved sites (p=0.02), inguinal/iliac involvement (p=0.009), lymphocytopenia (p=0.002) and elevated lactate dehydrogenase (p=0.01). The 7-year failure free survival (FFS) was 75% vs. 72% for patients with normal vs. elevated s beta(2)m (p=0.15). The corresponding 7-year overall survival (OS) rates were 86% vs. 52% (p=0.003). In multivariate analysis, elevated s beta(2)m was not predictive of FFS, but was independently associated with inferior OS (p=0.01), along with the number of involved sites (p<0.001). INTERPRETATION AND CONCLUSIONS: s beta(2)m is not a potent prognostic factor for FFS in optimally treated patients with HL. However s beta(2)m may be predictive of OS, probably due to its effect on the timing of treatment failure.  相似文献   
50.
Oxygenation-sensitive cardiovascular magnetic resonance (CMR) is a non-contrast technique that allows the non-invasive assessment of myocardial oxygenation. It capitalizes on the fact that deoxygenated hemoglobin in blood can act as an intrinsic contrast agent, changing proton signals in a fashion that can be imaged to reflect the level of blood oxygenation. Increases in O2 saturation increase the BOLD imaging signal (T2 or T2*), whereas decreases diminish it. This review presents the basic concepts and limitations of the BOLD technique, and summarizes the preclinical and clinical studies in the assessment of myocardial oxygenation with a focus on recent advances. Finally, it provides future directions and a brief look at emerging techniques of this evolving CMR field.  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