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   8990篇
  免费   665篇
  国内免费   460篇
耳鼻咽喉   49篇
儿科学   501篇
妇产科学   258篇
基础医学   1073篇
口腔科学   687篇
临床医学   1002篇
内科学   1590篇
皮肤病学   62篇
神经病学   281篇
特种医学   410篇
外国民族医学   1篇
外科学   1403篇
综合类   1389篇
预防医学   705篇
眼科学   154篇
药学   399篇
  4篇
中国医学   79篇
肿瘤学   68篇
  2024年   9篇
  2023年   101篇
  2022年   137篇
  2021年   245篇
  2020年   260篇
  2019年   231篇
  2018年   235篇
  2017年   274篇
  2016年   321篇
  2015年   381篇
  2014年   579篇
  2013年   760篇
  2012年   553篇
  2011年   642篇
  2010年   545篇
  2009年   495篇
  2008年   456篇
  2007年   430篇
  2006年   446篇
  2005年   423篇
  2004年   319篇
  2003年   318篇
  2002年   225篇
  2001年   200篇
  2000年   207篇
  1999年   146篇
  1998年   133篇
  1997年   93篇
  1996年   85篇
  1995年   100篇
  1994年   89篇
  1993年   69篇
  1992年   69篇
  1991年   59篇
  1990年   50篇
  1989年   48篇
  1988年   43篇
  1987年   39篇
  1986年   40篇
  1985年   40篇
  1984年   39篇
  1983年   23篇
  1982年   31篇
  1981年   19篇
  1980年   21篇
  1979年   16篇
  1978年   13篇
  1977年   15篇
  1976年   9篇
  1972年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Septo-optic dysplasia (SOD) is a rare congenital condition of unknown cause, with a characteristic triad that includes optic nerve hypoplasia, pituitary function abnormalities and midline brain defects, in addition to a broad spectrum of symptoms and associations.A total of five clinical cases are presented, four of which met the complete classic triad. All of them showed a wide variety of ophthalmological, endocrinological and neurological alterations.Within the ophthalmological spectrum of SOD, papillary hypoplasia and ocular motility alterations (nystagmus, strabismus) stand out. Other less frequent ones may also appear, such as pupillary alterations, microphthalmia and coloboma.Given the suspicion of SOD, brain MRI scan should be performed, as well as consultation with the paediatric department in order to complete the study and indicate, if necessary, systemic treatment.  相似文献   
33.
34.
35.
PurposeFurther diagnostic testing may be required after a coronary computed tomography angiography (CTA) showing suspected coronary stenosis. Whether myocardial perfusion imaging (MPI) provides further prognostic information post-CTA remains debated. We evaluated the prognosis for patients completing CTA stratified for post-CTA diagnostic work-up using real-world data.MethodsWe identified all patients in our uptake area with angina symptoms undergoing first-time CTA over a 10-year period. Follow-up time was a median of 3.7 years [1.9–5.8]. The primary endpoint was a composite of myocardial infarction or death. The secondary endpoint was late revascularization.ResultsDuring the study period 53,351 patients underwent CTA. Of these, 24% were referred for further down-stream testing, 3,547 (7%) to MPI and 9,135 (17%) to invasive coronary angiography (ICA). The primary and secondary endpoints occurred in 2,026 (3.8%) and 954 (1.8%) patients. Patient-characteristic-adjusted hazard ratios for the primary and secondary endpoint using patients with a normal CTA as reference were 1.37 (1.21–1.55) and 2.50 (1.93–3.23) for patient treated medically, 1.68 (1.39–2.03) and 6.13 (4.58–8.21) for patients referred to MPI and 1.94 (1.69–2.23) and 9.18 (7.16–11.78) for patients referred for ICA, respectively. Adjusted analysis with stratification for disease severity at CTA showed similar hazard ratios for patients treated medically after CTA and patients referred for MPI and treated medically after the MPI.ConclusionIn patients completing coronary CTA, second-line MPI testing seems to identify patients at low risk of future events. MPI seems to have the potential to act as gatekeeper for ICA after coronary CTA.  相似文献   
36.
Transradial interventions (TRI) are becoming increasingly popular because of accumulating recent evidence suggesting improved survival and reduced morbidity. Complications, though rare, do occur, especially for operators on their learning curve. The complications are best prevented by utilization of proper technique. Forearm hematoma are preventable and easy to treat, but a delay in detecting and managing them can lead to disastrous consequences compartment syndrome being the most dreaded one. This review deals with tips and tricks to prevent as also treat the common and rare complications.  相似文献   
37.
38.
目的探讨对比剂注射部位对儿童复杂先天性心脏病CTA图像质量的影响。方法回顾性分析426例复杂先天性心脏病患儿的双源CT心脏大血管CTA图像,其中经上肢静脉注射154例(A组),以下肢静脉注射272例(B组),对A、B组CTA图像上腔静脉对比剂硬化束伪影,心腔、大血管CT值,右心房、右心室对比剂均匀度,心内结构及大血管显示清晰度进行对比。结果 A组图像上腔静脉内对比剂硬化束伪影评分为3.00±1.04,B组为3.96±1.08,优于A组,二者差异有统计学意义(P0.01),两组心腔、大血管平均CT值的差异均无统计学意义(P均0.05);两组心内结构、大血管、冠状动脉起源及近段图像清晰度主观评分差异均有统计学意义,B组均高于A组(P均0.05),而右心房、右心室对比剂均匀度评分的差异无统计学意义(P均0.05)。结论对比剂注射部位的选择对儿童先天性心脏病CTA图像质量有显著影响,经下肢浅静脉注射对比剂有助于消除上腔静脉对比剂伪影,提高图像质量。  相似文献   
39.

OBJECTIVE

The present study consisted of patients who underwent on-pump coronary artery bypass grafting (CABG) and off-pump CABG and investigated effect of using cardiopulmonary bypass (CPB) on the amount of postoperative drainage and blood products, red blood cell (RBC), free frozen plasma (FFP) given in the intensive care unit in 60-80-year-old patients who underwent CABG.

METHODS

The present study comprises a total of 174 patients who have undergone coronary artery bypass graft (off-pump or on-pump CABG) surgery in our clinic in between 2012-2015 year.

RESULTS

It was observed that the amount of drainage in the first 24 postoperative hours was lower in the on-pump CABG group (Group 1) when compared to off-pump group (Group 2) (Group 1 vs. Group 2; 703.5±253.8 ml vs. 719.6±209.4 ml; P =0.716). However, the amount of drainage in the second 24 hours was statistically significantly lower in the off-pump CABG group (Group 1 vs. Group 2; 259.8±170.6 ml vs. 190.1±129.1 ml; P =0.016). With regard to the amount of overall drainage, no statistically significant difference was observed between the two groups. Group 1 needed RBC transfusion higher than Group 2 (Group 1 vs. Group 2; 2.2±1.3 bag vs. 1.2±0.9 bag; P <0.001).

CONCLUSION

We can say that CPB influences the amount of second 24-hour drainage which indexed body surface area. In addition, CPB decreases hct, hb, thrombocyte count in ICU arrived, after 24 hours in postoperative period. Reduced thrombocyte counting effect can be appeared after 48 hours in the postoperative period of CPB.  相似文献   
40.
目的:探讨腹主动脉瘤合并髂动脉瘤的腔内修复术(EVAR)方法。方法:回顾性分析2007年8月—2014年3月35例腹主动脉瘤合并髂动脉瘤行EVAR术患者资料,其中9例合并单侧髂内动脉瘤,1例合并双侧髂内动脉瘤,14例合并单侧髂总动脉瘤(直径18 mm),11例合并双侧髂总动脉瘤,所用腔内技术包括栓塞髂内动脉瘤后覆盖,髂内动脉瘤单纯覆盖,"喇叭口"支架,以及"三明治"技术重建一侧髂内动脉等。结果:所有腔内技术均获得成功,手术时间(125±40)min,出血量(173±65)m L。术中发现内漏8例(22.9%),其中I型内漏4例(近端2例,远端2例)均经球囊扩张后内漏消失,III型内漏1例,经扩张及部分加弹簧圈栓塞后内漏消失,II型内漏2例及IV型内漏1例,均未予处理。35例术后随访6~60个月,无动脉瘤破裂,2例术后6个月发现腹主动脉瘤体增大,造影确诊远端I型内漏,经弹簧圈栓塞后内漏消失,其余33例瘤体直径无增大。结论:对于合并髂动脉瘤的腹主动脉瘤患者,有效处理髂内动脉,然后根据髂总动脉直径选择合适的治疗方法可以达到理想的近期效果。  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