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   21740篇
  免费   966篇
  国内免费   405篇
耳鼻咽喉   142篇
儿科学   291篇
妇产科学   104篇
基础医学   1325篇
口腔科学   185篇
临床医学   1539篇
内科学   1199篇
皮肤病学   68篇
神经病学   258篇
特种医学   489篇
外科学   11156篇
综合类   2373篇
预防医学   1055篇
眼科学   19篇
药学   1554篇
  12篇
中国医学   863篇
肿瘤学   479篇
  2024年   52篇
  2023年   728篇
  2022年   1186篇
  2021年   1487篇
  2020年   1292篇
  2019年   1142篇
  2018年   1147篇
  2017年   1198篇
  2016年   606篇
  2015年   615篇
  2014年   1753篇
  2013年   1560篇
  2012年   1237篇
  2011年   1355篇
  2010年   1016篇
  2009年   962篇
  2008年   917篇
  2007年   940篇
  2006年   639篇
  2005年   529篇
  2004年   401篇
  2003年   300篇
  2002年   240篇
  2001年   214篇
  2000年   200篇
  1999年   169篇
  1998年   140篇
  1997年   114篇
  1996年   100篇
  1995年   98篇
  1994年   65篇
  1993年   61篇
  1992年   58篇
  1991年   58篇
  1990年   46篇
  1989年   41篇
  1988年   46篇
  1987年   46篇
  1986年   31篇
  1985年   36篇
  1984年   43篇
  1983年   59篇
  1982年   37篇
  1981年   35篇
  1980年   23篇
  1979年   23篇
  1978年   12篇
  1977年   15篇
  1976年   9篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Cholesterol intakes in Britain have been re-estimated by analysing Total Diet samples taken in 1991 and from 1993 National Food Survey records. The Total Diet samples contained only 284 mg/day compared with 319 mg/day in 1987 and 337 mg/day in 1981, while the National Food Survey showed intakes had fallen to 238 mg/day from 259 mg/day in 1990 and 405 mg/day in 1970-75. More details of the intakes by adults in 1986/87 are given, and compared with the results from the other methods. Daily intakes of eight phytosterols were also estimated, the main ones being β-sitosterol, campesterol, stigmasterol and 57-stigmastenol whose intakes were 104, 49, 10 and 4 mg/day, respectively, in 1991. These intakes had increased since 1981, reflecting the rising consumption of vegetable oils.  相似文献   
82.
83.
珊瑚型人工髋关节置换术的临床随访及松动原因的分析   总被引:5,自引:0,他引:5  
自1983年至今应用珊瑚型人工髋关节置换术共54例60髋。其中人工全髋关节置换术34例40髋,人工股骨头置换术20例20髋。在54例60髋珊瑚型人工髋关节置换术中,有37髋随访6个月~13年,平均随访时间约7年,疗效满意率为85.1%,其中假体松动4例占14.8%,髋臼松动2例7.4%。假体松动原因是假体与股骨负重界面之间没有达到稳定接触,假体与髓腔形状不相匹配,修整髓腔松质骨时,髓腔扩大器应比假体小一号,避免假体与界面存留缝隙。对于髋臼发育不良的患者应避免髋关节旋转中心向外侧移位,应向内上方加深髋臼以减少水平移位距离,其次髋臼植骨加盖勿在负重区。  相似文献   
84.
Hip arthroplasty is a common orthopaedic procedure with proven long-term success and reliable results. A wide range of associated conditions may affect the outcome of the arthroplasty and the surgeon has to keep these in mind when planning the surgery. In this article, such situations are discussed and recommendations are drawn from the evidence available in literature.  相似文献   
85.
Abstract Closed suction drainage systems are commonly used in orthopaedic surgery, particularly in joint arthroplasty. The rationale for the use of drains is a theoretical reduction of wound haematomas and infection. However the benefit of using drains after total hip or knee arthroplasty is controversial. Several reports have shown that the use of drains does not reduce infection and morbidity and is an unnecessary and potentially dangerous practice. In fact most studies highlighted that at best their use appears to make no difference to important clinical outcomes. Recently a metaanalysis raised the question about the usefulness of closed suction drainage again, concluding that it has no major benefits. The purpose of this study was to review the evidences available concerning the utility of closed suction drainage outlining that this practice is not supported by clinical evidence.  相似文献   
86.
The impact of total hip arthroplasty on psychological functioning was examined in 51 patients; 25 females and 26 males with a mean age of 65 years (range 42–81 years). Assessments of psychological well-being and distress were made with the Mental Health Inventory. Life satisfaction, self-rated health, and pain ratings were also obtained. Assessments were made prior to surgery, immediately after surgery, and at a 2 month follow-up. The operation produced significant improvements in psychological well-being (P < 0.001), psychological distress (P < 0.001). life satisfaction (P < 0.01), self-rated health (P < 0.001), and pain (P < 0.001). It is concluded that the changes in medical and functional status following hip arthroplasty documented in previous research are accompanied by substantial improvements in psychological state, and that the inclusion of psychological factors in hip arthroplasty research will provide a more comprehensive assessment of outcome.  相似文献   
87.
Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable.  相似文献   
88.
王雪晨  姚永忠 《海南医学》2003,14(12):30-31
目的 探讨全胃切除术后保留幽门间置空肠代胃术的临床应用。方法 1987年至今,对60例胃癌患者临床应用保留幽门的间置空肠代胃术式,评估其疗效。结果 60例患者无手术死亡,术后幽门舒缩功能及代胃的食糜搅拌、贮存功能良好,无返流性食管炎、倾倒综合症、营养不良等并发症。结论 保留幽门的间置空肠双腔代胃术能明显地改善全胃切除术后患者的生活质量。  相似文献   
89.
肝病患者血清中总胆汁酸测定的意义   总被引:3,自引:0,他引:3  
采用全自动酶法分析法 ,测定 32 1例各种肝病患者血清总胆汁酸 (TBA)。结果表明 :血清总胆汁酸是一种较灵敏的肝功能指标。在各类肝病中 ,尤其是急性肝炎、肝硬化、肝癌患者的总胆汁酸 (TBA)浓度均明显高于正常对照组 (P<0 .0 1) ,并在肝功能常规指标改变不明显时对肝脏疾病的诊断有一定的价值  相似文献   
90.
Optimal surgery remains the mainstay of best outcome for rectal cancer. The demonstration, during the 3rd Annual Pelican Surgical Workshop Symposium, of an abdomino‐perineal excision (APE) performed in the ‘Berlin position’, further added to the debate on optimal surgical technique. Much interest was created at the 1st Pelican symposium with the demonstration, by the Swedish surgeon Dr Torbjorn Holm, of a prone APE and the delivery of a ‘cylindrical’ specimen and the potential to reduce local recurrence using this approach. The high rates of local recurrence following APE and the discussions as to optimal technique have led to the development of a proposed MERCURY Study Group study to assess the benefit of a radical APE, with careful assessment of the impact that this operation may have on morbidity. A German study has also been proposed adopting the UK's multidisciplinary team approach. It aims at targeting preoperative chemoradiotherapy at those patients in whom a radical APE or total mesorectal excision is likely to result in an involved surgical resection margin. In this article we review the evidence for improving the surgical technique for low rectal cancer. We believe improvements may be best achieved through continued European prospective, multi‐centre, multidisciplinary studies.  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