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   489篇
  免费   39篇
  国内免费   20篇
儿科学   22篇
妇产科学   9篇
基础医学   53篇
口腔科学   14篇
临床医学   54篇
内科学   73篇
皮肤病学   6篇
神经病学   58篇
特种医学   53篇
外科学   41篇
综合类   10篇
一般理论   1篇
预防医学   51篇
眼科学   20篇
药学   48篇
肿瘤学   35篇
  2023年   2篇
  2022年   9篇
  2021年   21篇
  2020年   13篇
  2019年   17篇
  2018年   16篇
  2017年   11篇
  2016年   17篇
  2015年   12篇
  2014年   15篇
  2013年   25篇
  2012年   27篇
  2011年   31篇
  2010年   26篇
  2009年   14篇
  2008年   29篇
  2007年   28篇
  2006年   27篇
  2005年   23篇
  2004年   20篇
  2003年   20篇
  2002年   20篇
  2001年   6篇
  2000年   8篇
  1999年   4篇
  1998年   14篇
  1997年   9篇
  1996年   13篇
  1995年   7篇
  1994年   5篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
  1990年   2篇
  1989年   7篇
  1988年   9篇
  1987年   5篇
  1986年   3篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1981年   4篇
  1980年   3篇
  1978年   3篇
  1977年   2篇
  1976年   1篇
  1975年   4篇
  1973年   1篇
  1972年   1篇
排序方式: 共有548条查询结果,搜索用时 78 毫秒
41.
A 61-year-old woman with a 30-year history of systemic lupus erythematosus treated with chloroquine sulfate presented with complete heart block, congestive heart failure, and findings of restrictive cardiomyopathy on echocardiogram. Thickening of mitral, aortic, and tricuspid valves along with mild to moderate valve regurgitation was also present. Magnetic resonance imaging showed increased gadolinium uptake in the interventricular septum and the left ventricular lateral wall. Endomyocardial biopsy specimen showed marked myocardial cytoplasmic vacuolation and extensive myelin figures. Seven months after discontinuation of chloroquine, she showed significant clinical improvement and reversal of cardiomyopathy on echocardiography. This is the first case report describing a cardiomyopathy with prolonged use of chloroquine involving the conduction system, cardiac valves, and the myocardium with reversal on discontinuation of the drug.  相似文献   
42.
Strangulation in child abuse: CT diagnosis   总被引:2,自引:0,他引:2  
Bird  CR; McMahan  JR; Gilles  FH; Senac  MO; Apthorp  JS 《Radiology》1987,163(2):373-375
The central nervous system is commonly affected in child abuse. Between April 1985 and July 1986 three infants were identified in whom the primary mode of injury had been strangulation. In each case computed tomography (CT) demonstrated a large cerebral infarction confined to vascular territories associated with small subdural hematomas. There was no history or visible evidence of significant head trauma. Autopsy of one infant confirmed the presence of a hemispheric infarct, thin subdural hematoma, and an area of subintimal hemorrhage in the carotid artery ipsilateral to the infarct. The remaining two patients survived with residual hemiparesis. CT findings of a large cerebral infarction with an associated subdural hematoma in an infant without a history of a significant trauma should suggest the possibility of child abuse and may be the primary manifestation of abuse in some patients.  相似文献   
43.
Onset of genetically determined neurodegenerative diseases is difficult to specify because of their insidious and slowly progressive nature. This is especially true for spinocerebellar ataxia (SCA) because of varying affection of many parts of the nervous system and huge variability of symptoms. We investigated early symptoms in 287 patients with SCA1, SCA2, SCA3, or SCA6 and calculated the influence of CAG repeat length on age of onset depending on (1) the definition of disease onset, (2) people defining onset, and (3) duration of symptoms. Gait difficulty was the initial symptom in two‐thirds of patients. Double vision, dysarthria, impaired hand writing, and episodic vertigo preceded ataxia in 4% of patients, respectively. Frequency of other early symptoms did not differ from controls and was regarded unspecific. Data about disease onset varied between patients and relatives for 1 year or more in 44% of cases. Influence of repeat length on age of onset was maximum when onset was defined as beginning of permanent gait disturbance and cases with symptoms for more than 10 years were excluded. Under these conditions, CAG repeat length determined 64% of onset variability in SCA1, 67% in SCA2, 46% in SCA3, and 41% in SCA6 demonstrating substantial influence of nonrepeat factors on disease onset in all SCA subtypes. Identification of these factors is of interest as potential targets for disease modifying compounds. In this respect, recognition of early symptoms that develop before onset of ataxia is mandatory to determine the shift from presymptomatic to affected status in SCA. © 2008 Movement Disorder Society  相似文献   
44.
郑贤育  陈昌  高芳华 《药学学报》1991,26(12):895-901
本文报道了间日疟根治药伯氮喹2位引入取代苄氧基或甲氧基,5位引入取代苯氧基的类似物的合成。其中以化合物39及45对疟原虫组织期裂殖体的作用最强,约氏疟原虫子孢子感染的小鼠喂服100mg/kg单剂,分别有80%及90%的受试小鼠未查见原虫血症。化合物45降至20mg/kg单剂时,80%的受试小鼠也未出现原虫;对小鼠的急性毒性低于伯氨喹。  相似文献   
45.
46.
BACKGROUND: Several substitutes for intact, viable platelets have been used for transfusion, both to people and in animal models, with varied success. Infusible platelet membrane (IPM) is prepared from human platelets. IPM retains the glycoprotein (GP)lb receptor and has platelet factor 3 activity (procoagulant activity). However, factor V, serotonin, a cytoplasmic marker enzyme (purine nucleotide phosphorylase), GPIIb/IIIa complex, and HLA class I and II antigens are all absent in IPM. STUDY DESIGN AND METHODS: IPM is prepared from outdated platelets. The platelets were disrupted by freezing and thawing; they were washed and heated to inactivate possible viral contaminants, and then the sonicated membrane microvesicle fraction was separated and lyophilized. The hemostatic activity of IPM was measured by its ability to reduce the prolonged bleeding time in thrombocytopenic rabbits. RESULTS: Administration of IPM at a dose of 2 mg per kg results in a substantial reduction in the bleeding time. In a series of 23 experiments, a median preinjection bleeding time of 15 minutes was reduced to 6 minutes within 4 hours after IPM administration. Administration of IPM did show a mild enhancement in the thrombogenicity index, as measured in the Wessler rabbit model. This enhancement is, however, not significant, as a thrombogenicity index value of up to 0.6 is clinically acceptable. CONCLUSION: IPM may have clinical potential as a substitute for platelets in the treatment of bleeding due to thrombocytopenia.  相似文献   
47.
The aim of this study is to evaluate the awareness, perception, sources of information, and knowledge of diabetes mellitus and periodontal health among Jordanians, to examine the factors related to their knowledge, and organize effective education programs. A random sample of 500 diabetic patients was recruited from three hospitals and three comprehensive health centers that represent both urban and rural populations in Jordan between September 25, 2006, and February 20, 2007. Completed questionnaires with the answers were returned by 405 participants (response rate was 81%). Only 28% indicated that they followed up gum diseases with the dentist; 48% were aware that diabetic patients are more prone to gum diseases and oral health complications. About a third (38%) recognized that their periodontal health might affect their glycaemic level. Television and Internet were the main source of knowledge for dentists with the rate of 50%. Knowledge about diabetes and periodontal health among diabetic patients is low, and majority of patients were unaware of the oral health complications of their disease and the need for proper preventive care. Issues on education need to be addressed. Therefore, appropriate educational programs should be planned according to community needs, and the target of these programs should be patients with irregular visits to the dentist and physicians. The clinical implication of our findings is that dentists, physicians, and other health providers should inspect diabetic patients for gum diseases each time they come for care and recommend that diabetic patient see a dentist regularly.  相似文献   
48.
Background  This study was designed to evaluate the structures, muscles, and fasciae of which the modiolus is composed. It can aid in the understanding and, therefore, the utilization of plastic surgery for the aesthetic or reconstructive treatment of that region, especially the angle of the mouth. Methods  Dissections of the midface were done on five different cadavers. They were of different races (3 males, 2 females). The anatomy of the modiolus was studied in detail. New anatomical observations were classified as type I through type VI. Results  The perifacial artery fascia contributed to the modiolus in four (80%) specimens and was not part of it in 1 (20%) specimen. The facial artery was anterior to it in one (20%) specimen, lateral in four (80%) specimens, and never medial to it. No significant relationship was observed between the perifacial artery fascia contribution to the modiolus and gender or race. Also, the location of the facial artery lateral or anterior to the modiolus was not significantly related to gender or race. In addition, the deep and superficial fasciae of the face converged not anterior to the masseter muscle but actually at the modiolus, which was different from observations made by others. Conclusion  The modiolus is of critical importance in aesthetic and reconstructive plastic surgery of the face.  相似文献   
49.
Type III hyperlipoproteinemia (HLP) is mainly found in homozygous apolipoprotein (APO) E2 (R158C) carriers. Genetic factors contributing to the expression of type III HLP were investigated in 113 hyper- and 52 normolipidemic E2/2 subjects, by testing for polymorphisms in APOC3, APOA5, HL (hepatic lipase) and LPL (lipoprotein lipase) genes. In addition, 188 normolipidemic Dutch control panels (NDCP) and 141 hypertriglyceridemic (HTG) patients were genotyped as well. No associations were found for four HL gene polymorphisms and two LPL gene polymorphisms and type III HLP. The frequency of the rare allele of APOC3 3238 G>C and APOA5 −1131 T>C (in linkage disequilibrium) was significantly higher in type III HLP patients when compared with normolipidemic E2/2 subjects, 15.6 vs 6.9% and 15.1 vs 5.8%, respectively, (P<0.05). Furthermore, the frequencies of the APOA5 c.56 G>C polymorphism and LPL c.27 G>A mutation were higher in type III HLP patients, though not significant. Some 58% of the type III HLP patients carried either the APOA5 −1131 T>C, c.56 G>C and/or LPL c.27 G>A mutation as compared to 27% of the normolipidemic APOE2/2 subjects (odds ratio 3.7, 95% confidence interval=1.8–7.5, P<0.0001). The HTG patients showed similar allele frequencies of the APOA5, APOC3 and LPL polymorphisms, whereas the NDCP showed similar allele frequencies as the normolipidemic APOE2/2. Patients with the APOC3 3238 G>C/APOA5 −1131 T>C polymorphism showed a more severe hyperlipidemia than patients without this polymorphism. Polymorphisms in lipolysis genes associate with the expression and severity of type III HLP in APOE2/2.  相似文献   
50.
Rola J 《Psychiatria polska》2007,41(2):203-216
The approach towards the issues of depression and mental health problems of mentally disabled persons is discussed in the paper. The author discussed the various susceptibilities, resistances and typical mental health disturbances of mentally disabled persons as well as their diagnostic criteria and methods of measuring them. A longer part of the paper concerns the approach towards depressive disorders in the population with developmental disabilities.  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