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   6293篇
  免费   643篇
  国内免费   122篇
耳鼻咽喉   73篇
儿科学   50篇
妇产科学   64篇
基础医学   687篇
口腔科学   245篇
临床医学   544篇
内科学   421篇
皮肤病学   216篇
神经病学   123篇
特种医学   513篇
外科学   2167篇
综合类   706篇
预防医学   200篇
眼科学   99篇
药学   393篇
  5篇
中国医学   243篇
肿瘤学   309篇
  2025年   17篇
  2024年   219篇
  2023年   268篇
  2022年   371篇
  2021年   340篇
  2020年   266篇
  2019年   221篇
  2018年   191篇
  2017年   209篇
  2016年   204篇
  2015年   242篇
  2014年   440篇
  2013年   400篇
  2012年   393篇
  2011年   414篇
  2010年   289篇
  2009年   280篇
  2008年   291篇
  2007年   265篇
  2006年   214篇
  2005年   201篇
  2004年   185篇
  2003年   145篇
  2002年   135篇
  2001年   123篇
  2000年   114篇
  1999年   100篇
  1998年   76篇
  1997年   69篇
  1996年   51篇
  1995年   43篇
  1994年   34篇
  1993年   29篇
  1992年   22篇
  1991年   29篇
  1990年   21篇
  1989年   18篇
  1988年   18篇
  1987年   12篇
  1986年   9篇
  1985年   14篇
  1984年   16篇
  1982年   8篇
  1981年   11篇
  1980年   7篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1975年   4篇
  1972年   4篇
排序方式: 共有7058条查询结果,搜索用时 15 毫秒
1.
Summary A system which can be used for injection or infiltration of large volumes of fluid is described. This consists of a syringe which fills automatically from a reservoir through an inlet/outlet valve.  相似文献   
2.
Diethyl maleate (DEM) which binds and thus depletes tissue glutathione levels was used to aggravate the injury and to determine its effect on incisional healing. A 5 cm dorsal midline skin incision was performed on 40 albino Wistar rats in two groups and then closed by interrupted sutures. Groups received 0.9% NaCl and DEM at a dosage of 1 mg/kg/day intraperitoneally for seven days, respectively. On postoperative days 7 and 14, histopathological assessment and tensile strengths were measured. The DEM treated group had a marked inflammation with poorly defined collagen formation and the tensile strength measurements revealed a significant decrease (p <0.001) on the 7t day. On the other hand, the first group showed better collagenization and a lesser degree of inflammation. However, on the 14th day, there was no noticeable histopathological difference between the two groups; but, tensile strength values of the second group were still lower (p <0.05). In this animal model, DEM postponed the healing process and reduced the tensile strength.  相似文献   
3.
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   
4.
K. Wester 《Acta neurochirurgica》1994,131(3-4):223-225
Summary The results of a total of 25 cranioplasties are reported. In 10 patients, a reinforced acrylic prosthesis was utilized. In the remaining 15 cases, the patient's own autoclaved bone flap was re-implanted. Six of these bone flaps were autoclaved to kill tumour cells, and was re-implanted during the same surgical procedure. In the remaining 9 patients, the flaps were removed to allow brain swelling, preserved in a freezer and re-implanted several months later. All the prostheses and re-implanted flaps were accepted by the patients without complications such as infections or resorption, and with cosmetically satisfying results. The tumour infiltrated flaps remained tumour free for the entire period of observation.  相似文献   
5.
In a randomized, blinded trial we assessed the value of adding preoperative infiltration of the surgical area with bupivacaine to a low dose epidural regimen for postoperative pain treatment. Forty–nine patients scheduled for major upper abdominal surgery during combined thoracic epidural (bupivacaine + morphine) and general anaesthesia were studied. Postoperative analgesia was epidural bupivacaine 10 mg hr-1 + morphine 0.2 mg hr-1 for 72 h. The patients randomly received preoperative infiltration of the surgical area with bupivacaine 0.25%, 40 ml (group I); or no infiltration (group II). Pain was evaluated at rest, during cough and during mobilization six and eight h after start of surgery, and at 8 a.m. and 4 p.m. on the following days until 72 h after start of surgery. The sensory level of analgesia was evaluated by pin prick. We found no difference between the two groups during rest and cough. However, during mobilization group I had lower pain scores compared to group II ( P < 0.05). There was a significant reduction in the need for supplemental intramuscular morphine in the treatment group compared to the control group ( P <0.05). Thus an enhanced analgesic effect was demonstrated by adding preoperative infiltration of the surgical area with local anaesthetic to a low dose epidural bupivacaine/morphine regimen after upper abdominal surgery.  相似文献   
6.
Intrasinusoidal infiltration of bone marrow (BM) may accompany several malignant lymphoproliferative disorders. In small B-cell lymphomas, this pattern is considered specific for splenic marginal zone lymphoma (SMZL) when exclusive or prominent, although it may occur in other subtypes of non-Hodgkin's lymphomas (NHLs) as a minor feature. Here we report 2 cases of mantle cell lymphoma (MCL) with a prominent intrasinusoidal BM infiltration pattern. Both patients presented with massive splenomegaly and peripheral blood involvement characterized by markedly atypical lymphocytes, but no lymphadenopathy. The cytological features and the phenotype of the lymphoma cells were diagnostic of MCL. The malignant B cells showed coexpression of B-cell markers (CD20+ and CD79a+), CD5 antigen, and cyclin D1 by immunohistochemistry. We discuss the specificity of an intrasinusoidal growth pattern in the bone marrow, emphasizing the importance of using a broader immunohistochemical panel in the differential diagnosis of intrasinusoidal BM infiltration by NHL.  相似文献   
7.
Summary The past decades have seen considerable shifts of emphasis in surgical care. The recognition that pus was not laudable, was followed by a realisation that not all complications were inevitable and that prophylaxis could effectively reduce the incidence of most common problems in the post-operative period. As anaesthesia has become safer, it has been possible to embark on more intricate and prolonged procedures and for sufficient time to be available to ensure adequate intraoperative care.These two phenomena have firstly increased the complexity of management in the post-operative period, and have brought this aspect of surgical care more obviously to the limelight. However, many separate disciplines are involved in the care of the patient post-operatively, and the Symposium was organised1 to bring the different groups together to identify the areas of recent development in the different specialities and to integrate the overall care of the individual patient.Abbreviations ARDS adult respiratory distress syndrome - DIC disseminated intravascular clotting  相似文献   
8.
9.
Summary A comparative study of four skin graft donor site dressings was undertaken. This was a prospective and cross-over study of 25 consecutive patients with burns up to 40% TBSA treated with split skin grafts. Each donor site was divided into four sections and covered with different dressings in order to evaluate their effectiveness in healing, the time required for complete epithelialization, patient acceptance and any intolerance or local infection. The results showed that the occlusive hydrocolloid dressing significantly decreases (p<0.01) the mean time required for complete healing (7.45 days) compared with a semiocclusive hydrocolloid (10.29 days), a polyurethane sheet (9.4 days) and the conventional dressing (10.04 days).Presented at the IV European Burns Congress in Barcelona, Spain, September 25, 1991 (Abstract No. 117)  相似文献   
10.
Background The traditional Chinese medicine Tongxinluo can protect myocardium against ischaemia/reperfusion injury, but the mechanism of its action is not well documented. We examined the involvement of nitric oxide in the protective role of Tongxinluo. Methods Miniswine were randomized to four groups of seven: sham, control, Tongxinluo and Tongxinluo coadministration with a nitric oxide synthase inhibitor Nω-nitro-L-arginine (L-NNA, 10 mg/kg i.v.). Three hours after administration of Tongxinluo, the animals were anaesthetised and the left anterior descending coronary artery ligated and maintained in situ for 90 minutes followed by 3 hours of reperfusion before death. Area of no reflow and necrosis and risk region were determined pathologically by planimetry. The degree of neutrophil accumulation in myocardium was obtained by measuring myeloperoxidase activity and histological analysis. Myocardial endothelial nitric oxide synthase activity and vascular endothelial cadherin content were measured by colorimetric method and immunoblotting analysis respectively.Results Tongxinluo significantly increased the local blood flow and limited the infarct and size of no reflow. Tongxinluo also attenuated myeloperoxidase activity and neutrophil accumulation in histological sections and maintained the level of vascular endothelial cadherin and endothelial nitric oxide synthase activity in the reflow region when compared with control group. The protection of Tongxinluo was counteracted by coadministration with L-NNA. Conclusions Tongxinluo may limit myocardial ischaemia and protect the heart against reperfusion injury. Tongxinluo regulates synthesis of nitric oxide by altering activity of endothelial nitric oxide synthase.  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