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   3654篇
  免费   189篇
  国内免费   24篇
耳鼻咽喉   76篇
儿科学   69篇
妇产科学   80篇
基础医学   472篇
口腔科学   67篇
临床医学   342篇
内科学   903篇
皮肤病学   24篇
神经病学   639篇
特种医学   118篇
外科学   387篇
综合类   8篇
一般理论   2篇
预防医学   166篇
眼科学   35篇
药学   212篇
中国医学   15篇
肿瘤学   252篇
  2023年   26篇
  2022年   44篇
  2021年   91篇
  2020年   60篇
  2019年   83篇
  2018年   102篇
  2017年   74篇
  2016年   109篇
  2015年   100篇
  2014年   148篇
  2013年   182篇
  2012年   276篇
  2011年   241篇
  2010年   152篇
  2009年   144篇
  2008年   251篇
  2007年   247篇
  2006年   240篇
  2005年   254篇
  2004年   223篇
  2003年   196篇
  2002年   194篇
  2001年   33篇
  2000年   19篇
  1999年   27篇
  1998年   56篇
  1997年   30篇
  1996年   16篇
  1995年   32篇
  1994年   19篇
  1993年   19篇
  1992年   15篇
  1991年   9篇
  1990年   16篇
  1989年   12篇
  1988年   8篇
  1987年   10篇
  1986年   11篇
  1985年   12篇
  1984年   13篇
  1983年   7篇
  1982年   15篇
  1981年   5篇
  1980年   9篇
  1979年   5篇
  1978年   3篇
  1976年   3篇
  1974年   8篇
  1973年   4篇
  1970年   4篇
排序方式: 共有3867条查询结果,搜索用时 15 毫秒
61.
Small-gauge vitreoretinal techniques have been shown to be safe and effective in the management of a wide spectrum of vitreoretinal diseases. However, the costs of the new technologies may represent a critical issue for national health systems. The aim of the study is to plan a Health Technology Assessment (HTA) by performing a comparative analysis between the 23- and 25-gauge techniques in the management of macular diseases (epiretinal membranes, macular holes, vitreo-macular traction syndrome). In this prospective study, 45–80-year-old patients undergoing vitrectomy surgery for macular disease were enrolled at the Torino Eye Hospital. In the HTA model we assessed the safety, clinical effectiveness, and cost and financial evaluation of 23-gauge compared with 25-gauge vitrectomies. Fifty patients entered the study; 14 patients underwent 23-gauge vitrectomy and 36 underwent 25-gauge vitrectomy. There was no statistically significant difference in post-operative visual acuity at 1 year between the two groups. No cases of retinal detachment or endophtalmitis were registered at 1-year follow-up. The 23-gauge technique was slightly more expensive than the 25-gauge: the total surgical costs were EUR1217.70 versus EUR1164.84 (p = 0.351). We provide a financial comparison between new vitreoretinal procedures recently introduced in the market and reimbursed by the Italian National Health System and we also stimulate a critical debate about the expensive technocratic model of medicine.  相似文献   
62.
63.
64.
65.
66.
67.
68.
OBJECTIVES: The aim of this study was to assess the potential value of hand-carried ultrasound (HCU) devices in the diagnosis and follow-up of patients with pleural effusion (PE) after cardiac surgery. METHODS: Seventy consecutive patients were evaluated at bedside early after cardiac surgery, in the upright sitting position, using an HCU device on hospital admission and every 3 days until hospital discharge. The posterior chest wall was scanned along the paravertebral, scapular, and posterior axillary lines. For each hemithorax, an effusion index was derived as the sum of the intercostal spaces between the lower and upper limits of the PE along the lines of scanning, divided by 3. A standard chest radiograph was performed in all patients on hospital admission and at hospital discharge, and was qualitatively scored (0, absent; 1, small; 2, large PE). The findings of the HCU device and radiograph were compared using kappa statistics and the Kruskal-Wallis test. RESULTS: A chest ultrasound was feasible in all patients (mean [+/- SD] time, 5 +/- 2 min). Compared with the chest ultrasound, a physical examination showed a sensitivity of 69% and a specificity of 77%. On hospital admission, the HCU device detected a PE in 72 of 140 hemithoraxes. Agreement with the finding of the radiograph was 76% (kappa = 0.52). In 15 hemithoraxes, the HCU device revealed a PE that had not been diagnosed using the radiograph. Conversely, in 18 hemithoraxes a PE that had been diagnosed with a radiograph was not confirmed by the HCU device. The correlation between ultrasound and radiographic scores was statistically significant (p < 0.001). At hospital discharge, a PE was present in 31 of 140 hemithoraxes according to the findings of the HCU device, and in 38 of 140 hemithoraxes according to the findings of the radiograph (agreement, 78%; kappa = 0.44). CONCLUSIONS: In patients early after cardiac surgery, HCU devices allow rapid PE detection and improve the clinical diagnosis. Compared to a radiograph, this method offers the unique advantage of the bedside evaluation of patients without the need for radiation exposure.  相似文献   
69.
70.
Percutaneous revascularization of saphenous vein grafts (SVGs) remains a challenging task. Drug-eluting stents (DESs) have been shown to decrease the incidence of restenosis in de novo native coronary artery lesions. However, their clinical value in SVGs remains to be established. We compared long-term clinical outcomes of percutaneous coronary intervention with DESs and bare metal stents (BMSs) for de novo lesions in SVGs. In a large prospective, multicenter registry, 360 patients underwent stenting of a de novo lesion in SVGs using BMSs (288 patients) or DESs (72 patients). Incidence of major adverse cardiac events (MACEs), including all-cause mortality, reinfarction, and target vessel revascularization, was recorded at a 12-month follow-up. Compared with the DES group, patients receiving BMSs were more likely to be men, to have chronic renal insufficiency or higher Charlson scores, but less likely to have undergone previous percutaneous coronary intervention. Incidence of MACEs at 12-month follow-up was similar in the 2 groups (17.8% in DES group vs 20.3% in BMS group, respectively, p = 0.460). Cox regression analysis identified age, chronic renal failure, cardiogenic shock at presentation, and ostial location of stenosis as independent predictors of long-term MACEs. In conclusion, our data suggest that rates of 12-month MACEs associated with the use of DESs and BMSs are similar in patients undergoing treatment of de novo lesions in SVGs.  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