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   1791篇
  免费   95篇
  国内免费   29篇
耳鼻咽喉   74篇
儿科学   72篇
妇产科学   66篇
基础医学   108篇
口腔科学   74篇
临床医学   154篇
内科学   489篇
皮肤病学   17篇
神经病学   91篇
特种医学   55篇
外科学   438篇
综合类   32篇
预防医学   44篇
眼科学   84篇
药学   49篇
中国医学   1篇
肿瘤学   67篇
  2024年   1篇
  2023年   10篇
  2022年   18篇
  2021年   31篇
  2020年   23篇
  2019年   36篇
  2018年   51篇
  2017年   36篇
  2016年   70篇
  2015年   117篇
  2014年   102篇
  2013年   123篇
  2012年   145篇
  2011年   151篇
  2010年   90篇
  2009年   70篇
  2008年   145篇
  2007年   157篇
  2006年   140篇
  2005年   140篇
  2004年   120篇
  2003年   69篇
  2002年   45篇
  2001年   5篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1989年   1篇
  1987年   1篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
排序方式: 共有1915条查询结果,搜索用时 15 毫秒
21.
Gorgulu N, Yelken B, Caliskan Y, Elitok A, Cimen AO, Yazici H, Oflaz H, Golcuk E, Ekmekci A, Turkmen A, Yildiz A, Sever MS. Endothelial dysfunction in hemodialysis patients with failed renal transplants.
Clin Transplant 2009 DOI: 10.1111/j.1399‐0012.2009.01160.x
© 2009 John Wiley & Sons A/S. Abstract: Background: Endothelial dysfunction (ED) is a common precursor and denominator of cardiovascular events including development of atherosclerosis. In this cross‐sectional study, we aimed to investigate ED, measured by coronary flow reserve (CFR) in hemodialysis (nHD) patients who were never transplanted and patients with failed renal transplants restarting hemodialysis (fTx‐HD). Methods: Forty nHD (24 males, mean age 39 ± 9 yr) and 43 fTx‐HD patients (27 males, mean age 36 ± 9 yr) were included in the study. Clinical and biochemical parameters, including high‐sensitive C‐reactive protein (hs‐CRP) levels were determined. Also, CFR measurements were used to evaluate ED. Results: There were no significant differences regarding age, gender, smoking status, systolic and diastolic blood pressure levels, mean duration of HD treatment as well as Kt/V(urea) values between the two groups. Time spent on dialysis in the nHD group and dialysis duration following failure of renal allograft in the fTx‐HD group were similar. Serum creatinine, hemoglobin, hematocrit, calcium and phosphorus levels were similar between the two groups as well. When compared to nHD group, serum total cholesterol (139 ± 3 vs. 154 ± 3 mg/dL, p = 0.045), serum albumin (3.8 ± 0.3 g/dL vs. 4.1 ± 0.2 g/dL, p < 0.0001) and CFR (1.60 ± 0.2 vs. 1.75 ± 0.3, p = 0.028) levels were significantly lower, while serum hs‐CRP levels (11 ± 15 mg/L vs. 3 ± 4 mg/L, p = 0.001) were significantly higher in the fTx‐HD group. Serum hs‐CRP negatively correlated (r = ?0254, p = 0.021), while serum albumin positively correlated (r = 0402, p = 0.001) with CFR values. Conclusion: ED is more prominent in fTx‐HD than the nHD patients. Inflammation, caused by failed renal allograft can be responsible for this abnormality.  相似文献   
22.
Background. Increased cardiovascular disease risk is very well known in nephrotic syndrome. Coronary flow reserve measurement by trans-thoracic echocardiography reflects coronary microvascular and endothelial function. However, diastolic filling abnormalities by echocardiography may indicate diastolic dysfunction. Our aim was to evaluate endothelial and diastolic functions by trans-thoracic echocardiography in nephrotic syndrome. Methods. Eighteen patients with nephrotic syndrome (five females, 34 ± 17 years) and 30 controls (10 females, 35 ± 10 years) were evaluated in this cross-sectional observational study. Age, weight, lipid profile, glucose, blood urea nitrogen, creatinine, serum albumin, total protein, C-reactive protein, erythrocyte sedimentation rate, blood pressures, 24-hour urine volume, and protein were recorded. Glomerular filtration rate was estimated by Cockcroft-Gault Formula. Doppler flow and other echocardiographic parameters were measured by Vivid 7 echocardiography. Results. Coronary flow reserve was significantly lower in patients than controls (p < 0.001) and was negatively correlated with proteinuria (p < 0. 001), creatinine levels (p?=?0.03), total cholesterol (p?=?0.02), C-reactive protein (p?=?0.02), and erythrocyte sedimentation rate (p?=?0.005). E/A ratio was significantly lower in patients than in controls (p?=?0.005). DT was significantly higher in patients than in controls (p?=?0.01) and isovolumic relaxation time was similar in both groups. Conclusion. Coronary flow reserve and left ventricular diastolic filling are significantly impaired in nephrotic syndrome. Proteinuria, serum creatinine, total cholesterol and inflammation may have all contributory effects on endothelial dysfunction. Early evaluation of patients with nephrotic syndrome should include coronary flow and diastolic function by echocardiography.  相似文献   
23.
The aim of this study is to investigate the healing effect of hyperbaric oxygen (HBO) on colonic anastomoses in the presence of experimentally induced peritonitis. Thirty-two rats were allocated randomly into short-term anastomosis (STA), short-term anastomosis + HBO treatment (STA+HBO), long-term anastomosis (LTA), and long-term anastomosis + HBO (LTA+HBO) treatment groups. The STA and LTA groups were administered fluid resuscitation and antibiotics for 3 and 7 days, respectively, whereas the HBO treatment groups received additional HBO therapy for 3 and 7 days, respectively. The rats were reoperated on the third and the seventh days of anostomoses for evaluation. The bursting pressures in STA+HBO and LTA+HBO therapy groups were significantly higher than those in groups with anastomoses alone (p <. 001 and p <. 01). HBO therapy did not affect the fibrotic index neither in STA nor in LTA groups (p >. 05 for both); however, it was significantly higher in LTA+HBO group than that in STA+HBO group (p <. 05). The hydroxyproline level was significantly higher in LTA group than in STA group (p <. 05), yet HBO therapy did not affect the hydroxyproline levels in STA or LTA groups (p >. 05 for both). It is concluded that hyperbaric oxygen treatment has positive effects on colonic anastomotic healing in case of peritonitis.  相似文献   
24.
Toker H, Akp?nar A, Ayd?n H, Poyraz O. Influence of smoking on interleukin‐1beta level, oxidant status and antioxidant status in gingival crevicular fluid from chronic periodontitis patients before and after periodontal treatment. J Periodont Res 2012; 47: 572–577. © 2012 John Wiley & Sons A/S Background and Objective: The aim of this study was to evaluate the impact of smoking on the relationship between interleukin‐1 (IL‐1β) and oxidation in patients with periodontitis and response to nonsurgical periodontal therapy. Material and Methods: Data were obtained from 30 patients with generalized chronic periodontitis (15 smokers and 15 nonsmokers) and from 10 periodontally healthy controls. IL‐1β level, total oxidant status (TOS) and total antioxidant status (TAS) were recorded in gingival crevicular fluid. Probing depth, clinical attachment level, gingival and plaque indices and bleeding on probing were also measured. The gingival crevicular fluid and clinical parameters were recorded at baseline and 6 wk after periodontal treatment. Results: The study showed statistically significant improvement of clinical parameters in both smokers and nonsmokers after periodontal treatment. Moreover, the baseline IL‐1β levels were significantly higher in smokers compared with nonsmokers (p < 0.05). After periodontal treatment, the IL‐1β levels were significantly reduced in both smokers and nonsmokers (p < 0.05). There were no significant differences in TOS and TAS between periodontitis patients and healthy controls at baseline and 6 wk after periodontal treatment. The level of IL‐1β in gingival crevicular fluid was positively correlated with TOS in both smokers and nonsmokers. Conclusions: Periodontal treatment improved the clinical parameters in both smokers and nonsmokers. The results confirm that periodontal therapy has an effect on IL‐1β levels in gingival crevicular fluid, but not on TOS and TAS.  相似文献   
25.
26.
27.
A transverse muscular band extending from the left pleura to the esophagus was detected during routine dissection of posterior mediastinum in Anatomy Department of Ege University Medical Faculty. As a result of a detailed review of the literature, we found that this structure is named as the pleuro-esophageal muscle. This muscle was made of smooth fibers, acting as an anchoring structure to the lower part of the esophagus. While the entire esophageal muscle is smooth in the early stage of fetal development, this muscle probably derives as an early separation from the esophagus.  相似文献   
28.
The aim of this study is to investigate postoperative complications, mortality rates, and to determine the factors affecting mortality on the patients receiving warfarin therapy preoperatively, as well as comparing the results obtained from emergency and elective surgeries. Surgical outcomes of 61 patients on long-term oral anticoagulation with warfarin who underwent surgery in our center were retrospectively reviewed over an 8-year period. Thirty-three (54.1%) patients were female, with a mean age of 53 years. Mitral valve replacement (62.3%) was the most frequent indication for chronic anticoagulation therapy. Twelve out of 61 (19.2%) patients underwent emergency surgery; 59 (96.7%) operations were classified as major surgery. We did not observe any thromboembolic events on patients receiving our bridging therapy protocol. Cardiopulmonary dysfunction (CPD; 19.7%) and hemorrhage (16.4%) were the most encountered postoperative complications. Presence of CPD, bleeding, endocarditis, and mortality were statistically significant for emergency surgeries when compared with the results obtained from elective surgeries. There were 5 (8.2%) deaths observed during follow-up. It was found that advanced age, prolonged duration of operations, and presence of CPD had a statistically significant effect on mortality (P < 0.05). The patients receiving oral anticoagulant had high postoperative complication and mortality rates. This case was more evident in emergency surgeries. It is recommendable that as mortality is more apparent in the patients who undergo emergency surgeries—being older, having long duration of operations as well as CPD. Therefore during the postoperative follow-up process, the patients should be closely monitored.Key words: Emergency, Postoperative complications, Morbidity, Mortality, WarfarinThromboembolism is a major global health concern contributing to more than 0.5 million deaths in Europe and up to 300,000 deaths in the United States each year.1 Versatile arrays of anticoagulant and/or anti-aggregant agents are available. They are used to treat and prevent thrombosis occurring as a result of venous stasis, valvular heart disease, prosthetic valves, atrial fibrillation, or myocardial infarction. After using these medications, patients who require elective or emergency surgery represent a specific population; moreover, they are prone to developing either excessive bleeding or thrombosis.The annual incidence of major bleeding as a result of oral anticoagulant (OAC) use is reported between 2 and 5%.2 Patients on OAC may require elective or sometimes emergency surgical or invasive procedures. There is no consensus on standard protocol to follow for those who require perioperative management.3In the current literature, there are limited numbers of studies regarding the discussions about the operations in general surgery patient population receiving warfarin treatments. In this retrospective study, our aim was to document the complications and outcomes of general surgical procedures implemented on patients receiving warfarin. Along with the comparison of the emergency and elective surgeries performed, we also aimed to determine the factors affecting mortality.  相似文献   
29.
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