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   3119篇
  免费   297篇
  国内免费   50篇
耳鼻咽喉   34篇
儿科学   125篇
妇产科学   54篇
基础医学   288篇
口腔科学   868篇
临床医学   330篇
内科学   542篇
皮肤病学   71篇
神经病学   172篇
特种医学   52篇
外科学   209篇
综合类   263篇
现状与发展   1篇
预防医学   124篇
眼科学   94篇
药学   160篇
  2篇
中国医学   39篇
肿瘤学   38篇
  2024年   5篇
  2023年   117篇
  2022年   109篇
  2021年   151篇
  2020年   174篇
  2019年   155篇
  2018年   134篇
  2017年   171篇
  2016年   133篇
  2015年   140篇
  2014年   195篇
  2013年   212篇
  2012年   156篇
  2011年   168篇
  2010年   98篇
  2009年   117篇
  2008年   134篇
  2007年   131篇
  2006年   118篇
  2005年   120篇
  2004年   77篇
  2003年   76篇
  2002年   58篇
  2001年   51篇
  2000年   40篇
  1999年   35篇
  1998年   38篇
  1997年   21篇
  1996年   34篇
  1995年   39篇
  1994年   22篇
  1993年   16篇
  1992年   38篇
  1991年   23篇
  1990年   15篇
  1989年   8篇
  1988年   18篇
  1987年   20篇
  1986年   14篇
  1985年   18篇
  1984年   13篇
  1983年   4篇
  1982年   10篇
  1981年   8篇
  1980年   10篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1976年   2篇
  1973年   3篇
排序方式: 共有3466条查询结果,搜索用时 46 毫秒
1.
目的:探讨福赛类杆菌与人类唾液富脯蛋白相互作用的蛋白分子。方法:Western—blot方法。将人工合成唾液富脯蛋白用生物素标记,福赛类杆菌全菌蛋白凝胶电泳,半干转移至纤维膜上,观察二者的相互作用。结果:富脯蛋白能与分子量为85KD、65KD、60KD、以及49KD的福赛类杆菌蛋白发生结合。结论:福赛类杆菌存在与人类唾液富脯蛋白相互结合的粘附素。  相似文献   
2.
Persistent developmental stuttering (PDS) shares clinical features with task-specific dystonias. In these dystonias, intracortical inhibition is abnormally weak. We therefore sought to determine intracortical inhibition and intracortical facilitation in PDS. In 18 subjects with PDS since childhood (mean age, 39.4 [SD 13.0] years) and 18 speech-fluent controls (43.6 [14.3] years), we investigated resting and active motor thresholds as well as intracortical inhibition and facilitation of the optimal representation of the abductor digiti minimi of the dominant hand using transcranial magnetic stimulation. In PDS, the resting and active motor thresholds were increased, whereas intracortical inhibition and facilitation were normal. Normal intracortical excitability makes a pathophysiological analogy between focal dystonia and PDS less likely. The enhanced motor threshold suggests reduced motor cortical neuronal membrane excitability in PDS.  相似文献   
3.
Two elderly women complaining of intermittent claudication complicated with persistent sciatic artery are herein reported. A direct femoral arteriogram showed hypoplasty of the superficial femoral artery and an unnatural anatomical relationship between the distal superficial femoral artery and the proximal popliteal artery, thus suggesting the presence of persistent sciatic artery. The diagnosis of persistent sciatic artery was finally made based on the aortography findings including the iliac arterial system and computed tomography (CT) scan. Magnetic resonance imaging (MRI) was helpful to demonstrate the entire image of this anomaly in cases with non-thrombolized sciatic artery. These diagnostic methods were useful in designing the optimal surgical strategy. The first case with a gluteal pulsating mass underwent exclusion of the persistent sciatic artery including the aneurysm through a retroperitoneal approach with a combination of femorotibial bypass, while the second case with thrombosed persistent sciatic artery only underwent femoropopliteal bypass. To recognize such a rare lesion, awareness of the differential diagnosis is important, and to provide appropriate treatment, an accurate whole image including adequate angiography, a CT scan, and magnetic resonance imaging is necessary.  相似文献   
4.
A retrospective multicentre study of 341 children with persistent/recurrent, isolated haematuria is described. The haematuria was isolated for at least 6 months at the beginning of observation. The duration of follow-up was 2–5 years in 201, 5–10 years in 119, 10–15 years in 19, and over 15 years in 2 cases. Of these patients 47.8% became symptom-free. In 18.4% the haematuria remained isolated; in 13.8% it was combined with proteinuria over 250 mg/day more than 2 years later. The occurrence of associated proteinuria increased progressively with time. It was 8.6% between the 3rd and 5th years, and 37.0% after the 5th year. Renal biopsy was performed because of the symptoms of glomerular disease in 47 cases at an average time of 12 months following the appearance of proteinuria. Proteinuria appeared after a 2–5, 5–10, 10–15 and more than 15 years follow-up period in 16, 23, 6, and 2 patients respectively; 14 of them had Alport's nephropathy. The percentage of more serious azotaemia was 1.7 (creatinine clearance: 10–50 ml/min per 1.73 m2) and 0.3 (creatinine clearance: < 10 ml/min per 1.73 m2). Mortality was 0.58%. Most of the patients who developed severe azotaemia had persistent microscopic haematuria at the beginning. The prevalence of hypertension was only 1.2%. The time of its appearance was above 5 years in 2 and below 5 years in 2 cases. All these patients had chronic glomerulonephritis. The haematuria was associated with hypercalciuria in 19.9%. In 14.3% of the overall group of patients urolithiasis developed 2–15 years after onset. All of these had hypercalciuria. Our findings suggest that symptoms of isolated haematuria may last for a longterm period and need systematic control. When proteinuria and/or hypertension is associated with haematuria a worse prognosis can be expected.Participating paediatric hospitals and university departments: Second Department of Paediatrics, I. Semmelweis Medical University of Budapest (M. Visy); Department of Paediatrics, University Medical School of Pécs (V. Jászai); Department of Paediatrics, A. Szent-Györgyi Medical University of Szeged (I. Haszon, S. Túri); County Children's Hospital, Miskolc (Á. Vissy); P. Heim Children's Hospital, Budapest (Z. Czirbesz); County Children's Hospital, Györ (Zs. Szelid); Buda-Children's Hospital, Budapest (I. Ferkis); I. Apáthy Hospital, Budapest (J. Kisbán); János Hospital, Budapest (I. Marosváry); Hospital of Hungarian State Railway, Budapest (J. Fehér); L. Madarász Hospital, Budapest (F. Kalmár); South Pest Hospital, Budapest (G. Halász); County Children's Hospital, Pécs (E. Kolman); County Children's Hospital, Gyula (P. Sipos); County Children's Hospital, Szolnok (I. Jaksics); County Children's Hospital, Debrecen (Á. Miskolczi); County Children's Hospital, Tatabánya (I. Kiss); County Children's Hospital, Eger (M. Frank, E. Ladányi); County Children's Hospital, Nyíregyháza (E. Bujdosó); County Children's Hospital, Szombathely (M. Andics); Kerepestarcsa Hospital, Budapest (M. Marcell); Komárom Hospital, Komárom (J. Kecskés)  相似文献   
5.
In embryology, a persistent connection of the left superior vena cava to the left atrium rarely coexists with a coronary sinus. We herein report an unusual case of persistent left superior vena cava terminating in a left atrium with normal coronary sinus, which was revealed at the time of permanent pacemaker implantation after a second operation for recurrent left atrioventricular valve regurgitation. Because this anomaly had gone undiagnosed at the first operation, we were unable to diagnose it prior to the second operation, because the preoperative coronary angiogram clearly demonstrated a coronary sinus that was not dilated. We would have repaired the anomaly using a patch or other procedure had it been diagnosed before the second operation in order to prevent cyanosis or brain complications secondary to right-to-left shunting. One should always be on guard for this rare condition.  相似文献   
6.
Objective Report of two cases of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), with typical penile lesions. Differential diagnosis of persistent penile plaques. Background Following remission of the generalized eruption of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), it is not unusual to see a single remaining lesion localized on the penis. Since Sulzberger et al. (Sulzberger MB, Witten VH, Hunt JA. Puzzling persistent penile plaques. Arch Dermatol 1956:73:101-109) reviewed dermatoses presenting with puzzling persistent penile plaques in 1955, further dermatoses have evolved as important differential diagnoses. Much controversy has arisen as to the justification of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe) as a disease entity. Conclusions Diagnosis of most cases of persistent plaques of dermatitis on the penis is possible with a careful examination of the entire skin, and a thorough history to discover past lesions. The possibility of malignancy makes a biopsy mandatory. Exudative discoid and lichenoid chronic dermatosis (Sulzberger-Garbe) typically responds well to systemic steroids. Intrale-sional triamcinolone acetonide has been demonstrated to be effective in the treatment of a persistent penile plaque in exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), and may be helpful in discontinuing or reducing systemic therapy to a level compatible with long-term treatment.  相似文献   
7.
目的探讨急非淋白血病完全缓解后巩固治疗与缓解期的关系。方法对30例坚持与未坚持完全缓解后巩固化疗的急非淋患者(每组15例)进行对照研究。比较两组患者的完全缓解期。结果两组患者入院时情况、治疗及达完全缓解时间经统计学处理无明显差异(P>0.05);而坚持巩固化疗组平均持续完全缓解期(19.8mo)明显长于对照组(8.4mo),统计学具有显著差异(P<0.01)。结论急非淋白血病达完全缓解后,坚持骨髓抑制性治疗对延长完全缓解期以达长期生存目的具有重要意义。  相似文献   
8.
介绍微电脑促醒仪的基本结构、工作原理、主要技术特点及临床应用等内容。该仪器运用微电脑控制的促醒仪产生电刺激信号,通过射频耦合方式(或直接耦合方式)传递到植物生存状态患者脑干网状结构刺激电极,激活网状激动系统,促使Pcrsistent Vegtative State,PVS患者康复,取得了较好的效果。  相似文献   
9.
Before completion of polarization, Madin-Darby canine kidney (MDCK) cells showed high infectivity and progeny production of herpes simplex virus type 1 infection. After polarization or formation of tight junctions, the infectivity and virus replication in MDCK cells was restricted significantly. The disruption of tight junctions by depletion of Ca2+ resulted in increasing virus infectivity and productivity. Mechanical disruption of tight junctions by scratching the cell monolayers with injection needle allowed markedly the replication of HSV-I in the cells aligned along the injured area. In polarized MDCK cells the progeny were released preferentially from the apical surface of the cells. These data suggest that because polarized MDCK cells mimic the epithelial cell layers, this cell line is helpful for determining the factors which regulate viral transmission in the human body. © Wiley-Liss, Inc.  相似文献   
10.
L. Frost    P. Johansen    S. Pedersen    N. Veien    P. AabelØstergaard  M. H. Nielsen 《Allergy》1985,40(5):368-372
A follow-up study of 202 children who had received hyposensitization with aluminium-containing allergens showed that 1-3 years after cessation of hyposensitization 13 children still had severely pruiginous treatment-resistant subcutaneous nodules in their forearms. Because of their long persistence the nodules of six children were studied in detail. Histologically, the nodules showed infiltration with lymphocytes (forming germinal centres), macrophages, plasma cells, mast cells and a few eosinophils. In five patients aluminium crystals were found scattered between the cells and, in addition, the phagosomes of the macrophages contained aluminium. Patch tests for aluminium were positive in four of the six patients. It is concluded that persisting nodules during hyposensitization with aluminium-containing allergens may indicate development of aluminium hypersensitivity, and if this is confirmed hyposensitization should be discontinued.  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