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   1201篇
  免费   91篇
  国内免费   6篇
耳鼻咽喉   12篇
儿科学   9篇
妇产科学   15篇
基础医学   210篇
口腔科学   106篇
临床医学   149篇
内科学   283篇
皮肤病学   7篇
神经病学   96篇
特种医学   37篇
外科学   166篇
综合类   6篇
预防医学   59篇
眼科学   6篇
药学   73篇
中国医学   3篇
肿瘤学   61篇
  2023年   6篇
  2022年   25篇
  2021年   46篇
  2020年   24篇
  2019年   41篇
  2018年   37篇
  2017年   16篇
  2016年   32篇
  2015年   34篇
  2014年   53篇
  2013年   65篇
  2012年   89篇
  2011年   103篇
  2010年   58篇
  2009年   44篇
  2008年   93篇
  2007年   89篇
  2006年   91篇
  2005年   76篇
  2004年   68篇
  2003年   58篇
  2002年   39篇
  2001年   12篇
  2000年   10篇
  1999年   8篇
  1998年   13篇
  1997年   8篇
  1996年   10篇
  1995年   7篇
  1994年   5篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1986年   3篇
  1985年   2篇
  1984年   4篇
  1981年   2篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1974年   2篇
  1967年   1篇
  1965年   1篇
排序方式: 共有1298条查询结果,搜索用时 62 毫秒
171.
The occurrence of arteriovenous fistula (AV) after finger replantation is a very rare complication. Since the first replantation performed in the Czech Republic in 1979, there has been one such case. A four-finger replantation was done for an injury on the right dominant hand on a 29-year-old patient. After 6 months, an arteriovenous fistula developed on the fourth finger. The other fingers were not affected. Following examination by digital subtraction angiography, selective ligature of the common digital artery for the fourth interdigital space was performed. Catheterization and embolization methods were not used. After detailed analysis of the factors which may have caused this complication, the following preventative and therapeutic approach is proposed. It is necessary to avoid tissue damage caused by cold. The advisable rate should be at least 1:1 between venous drainage of the finger in the area of the basic phalanx and the arterial supplementation. It would be better, however, to have the ratio at 2:1 or more. In case of the AV fistula formation before radical intervention, selective ligation of an artery causing vascular dilatation is advantageous.  相似文献   
172.
INTRODUCTION: A fundamental prerequisite for using degradable synthetic biopolymers as composite skin substitutes is the ability to establish vascular tissue. PEGT/PBT block-copolymer matrices have previously been shown as a favorable dermal substitute. In this study, quantitative data on neovascularization of PEGT/PBT block-copolymer matrices are presented. MATERIALS AND METHODS: PEGT/PBT-block-copolymer discs of three different pore diameters (1: < 75 microm, 2: 75-212 microm, 3: 250-300 microm) were implanted into dorsal skinfold chambers of balb/c mice. Histological sections were evaluated 7, 14, and 21 days post implantation by light and scanning electron microscopy. Blood vessel analysis was performed by means of digital image analysis (n = 288) of hematoxylin/eosin stained sections within apical (AOF) and basal (BOF) observation fields of the matrices. RESULTS: Twenty-one days after implantation the density of blood vessels within the BOF of the scaffolds with a pore size of 75-212 and 250-300 microm were 4.6 +/- 0.45 and 5.8 +/- 0.62 (mean +/- S.E.M.; blood vessel profiles (BVF)), respectively. In <75 microm scaffolds, smaller numbers of BVF were found (4.2 +/- 0.39). In contrast, the evaluation within the AOF revealed significantly higher numbers of BVF in 75-212 microm group (3.5 +/- 0.49) and 250-300 microm group (4.5 +/- 0.66) as compared to the < 75 microm group (2.3 +/- 0.48). CONCLUSION: There is evidence that the three-dimensional structure of PEGT/PBT-block-copolymer (pore size structure) influences neovascularization. The porous structures of copolymer matrices with adequate interconnection of pores (pore sizes of 75-212 and 250-300 microm) are characterized by faster ingrowth of vascular tissue.  相似文献   
173.
174.
Using functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) source dipole analysis in 10 normal subjects, two electrical source dipoles in the contralateral fronto-parietal operculum were identified during repetitive painful subepidermal stimulation of the right index finger. The anterior source dipole peaking at 79 +/- 8 ms (mean +/- SD) was located in the frontal operculum, and oriented tangentially toward the cortical surface. The posterior source dipole peaking at 118 +/- 12 ms was located in the upper bank of the Sylvian fissure corresponding to the second somatosensory cortex (S2). The orientations of the posterior source dipoles displayed large variability, but differed significantly (P < 0.05) from the orientations of the anterior source dipoles. Electrical sources and fMRI clusters were also observed in ipsilateral fronto-parietal operculum. However, due to low signal-to-noise ratio of ipsilateral EEG sources in individual recordings, separation of sources into anterior and posterior clusters was not performed. Combined fMRI and source dipole EEG analysis of individual data suggests the presence of two distinct electrical sources in the fronto-parietal operculum participating in processing of somatosensory stimuli. The anterior region of the fronto-parietal operculum shows earlier peak activation than the posterior region.  相似文献   
175.
Urokinase-type plasminogen activator (uPA) is a serine protease that not only displays fibrinolytic function but also modulates innate and adaptive immune responses. In the present study, we assessed whether uPA acts as an endogenous antibiotic. It has been demonstrated that uPA inhibits growth of Staphylococcus aureus both in vivo and in vitro. Importantly, the bactericidal properties of uPA are associated with the serine protease domain of the molecule but are not dependent on its plasminogen-activation potential and cannot be inhibited by plasminogen activator inhibitor type 1 (PAI-1). In a murine infection model, uPA treatment alleviated staphylococcal sepsis by inhibiting bacterial growth. To further evaluate the changes in uPA levels during the course of staphylococcal infection, total uPA and active uPA levels were analyzed in plasma and in kidney homogenates. Expression of total uPA was constant, but PAI-1 levels were dramatically increased in plasma and in kidney homogenates during the course of staphylococcal infection. After infection with staphylococci, the level of metabolically active uPA was unaltered in plasma but was significantly decreased in kidney homogenates. Active uPA levels were inversely related to PAI-1 levels and to bacterial loads in kidney homogenates. In conclusion, we report that uPA acts as an endogenous antibacterial substance that might constitute the first line of host defense against staphylococcal infection. The decreased active uPA levels in infected organs might be due to the dramatically increased PAI-1 production during S. aureus infection.  相似文献   
176.
Sternal osteomyelitis and poststernotomy mediastinitis is a severe and life-threatening complication after the cardiac surgery. The incidence ranges up to 3% with a mortality rate up to 29%. In addition, postoperative infections after sternotomy are associated with prolonged hospital stay, increased healthcare costs and impaired quality of patient life, representing an economic and social burden. The emergence of increasing antimicrobial resistant bacteria augments the importance of postsurgical infections since the antimicrobial choices are becoming limited. Furthermore, the incidence of infection is an indicator for the quality of patient care in the international benchmark studies. Although several therapy strategies are nowadays present in clinical practice, there is a lack of evidence-based surgical consensus for treatment of this surgical complication. In most cases the poststernotomy mediastinitis involves surgical revision with debridement, open dressing and/or vacuum-assisted therapy. After the granulation tissue on open chest wound is achieved, secondary closure and/or reconstruction with vascularized soft tissue flaps, such as omentum or pectoral muscle is performed. It seems there is a need for more effective surgical treatment of poststernotomy wound infections, which may address the prolonged hospitalization and reduce the number of surgical interventions and with this also the perioperative morbidity. In light of this we propose a randomized study comparing new delayed primary closure of the sternum to the secondary vacuum-assisted closure.  相似文献   
177.
Increased mortality has been reported in patients starting dialysis after kidney graft failure. In this study we analyzed this subgroup of dialysis patients based on the data from the Slovenian Renal Replacement Therapy Registry. Patients starting dialysis after graft failure in the period between 2004 and 2008 were identified from the registry. Demographic, clinical and treatment data, as well as survival were compared to incident dialysis patients, who were on the waiting list or preparing for enrollment. There were 49 patients starting dialysis after 7.9 ± 6.4 years spent with a functioning graft and a total of 13.7 ± 7.4 years on renal replacement therapy. Their mean age was 48.3 ± 11.0 years (vs. 48.2 ± 13.9 years in incident patients, P = 0.96), 53% were male, and all were on hemodialysis. By the end of 2008, 8 (16%) patients had been re-transplanted (after a median of 27.5 months) and 11 (23%) had died (after a median of 1.4 months of dialysis). The cause of death was infection in five patients, a cardiovascular event in three, malignancy in two, and a cerebrovascular event in one patient. Deceased patients were significantly older, but similar to survivors in other parameters. Unadjusted one- and three-year survival rates after graft failure were both 77%, which was significantly worse than in incident patients (P < 0.001). To conclude, patients after graft failure have increased mortality in the first year after starting dialysis, but patients surviving the first year have good survival thereafter. Studies focusing on the early period after graft failure are necessary to improve outcomes.  相似文献   
178.

Purpose  

The diagnosis of microbial ureteral stent colonisation (MUSC) is difficult, since routine diagnostic techniques do not accurately detect microorganisms embedded in biofilms. New methods may improve diagnostic yield and understanding the pathophysiology of MUSC. The aim of the present study was to evaluate the potential of sonication in the detection of MUSC and to identify risk factors for device colonisation.  相似文献   
179.
180.
A 76-year-old female patient with cold agglutinin autoimmune haemolytic anaemia (CAHA) is presented. The haemolysis worsened during infection. Earlier, the patient underwent an unsuccessful treatment with steroids, chlorambucil , folic acid and heated erythrocyte transfusion. We treated her with monoclonal anti-CD20 antibody Rituximab (RTX) weekly for four consecutive weeks. After three cycles, the signs of haemolysis slowly disappeared and haemoglobin completely normalized. We continued with the maintenance treatment with RTX every third month for 2 years. The patient is in complete remission. This case report emphasizes the importance of the use of RTX as a therapy for immune cytopenia. Patients with CAHA usually fail to respond to standard treatment. Since CAHA is a very rare condition, only some case reports and 2 studies reported on the positive effects of RTX. Although expensive, RTX has many advantages, such as quick and long-term efficiency and only a few side effects.  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