全文获取类型
收费全文 | 19681篇 |
免费 | 1130篇 |
国内免费 | 133篇 |
专业分类
耳鼻咽喉 | 193篇 |
儿科学 | 472篇 |
妇产科学 | 437篇 |
基础医学 | 2329篇 |
口腔科学 | 626篇 |
临床医学 | 1544篇 |
内科学 | 5836篇 |
皮肤病学 | 470篇 |
神经病学 | 1561篇 |
特种医学 | 449篇 |
外科学 | 2708篇 |
综合类 | 120篇 |
一般理论 | 9篇 |
预防医学 | 1352篇 |
眼科学 | 371篇 |
药学 | 1130篇 |
中国医学 | 64篇 |
肿瘤学 | 1273篇 |
出版年
2024年 | 15篇 |
2023年 | 153篇 |
2022年 | 350篇 |
2021年 | 781篇 |
2020年 | 365篇 |
2019年 | 726篇 |
2018年 | 796篇 |
2017年 | 506篇 |
2016年 | 512篇 |
2015年 | 546篇 |
2014年 | 853篇 |
2013年 | 961篇 |
2012年 | 1682篇 |
2011年 | 1697篇 |
2010年 | 887篇 |
2009年 | 812篇 |
2008年 | 1281篇 |
2007年 | 1300篇 |
2006年 | 1141篇 |
2005年 | 1087篇 |
2004年 | 995篇 |
2003年 | 849篇 |
2002年 | 831篇 |
2001年 | 187篇 |
2000年 | 191篇 |
1999年 | 188篇 |
1998年 | 131篇 |
1997年 | 118篇 |
1996年 | 89篇 |
1995年 | 69篇 |
1994年 | 63篇 |
1993年 | 59篇 |
1992年 | 84篇 |
1991年 | 70篇 |
1990年 | 66篇 |
1989年 | 55篇 |
1988年 | 48篇 |
1987年 | 49篇 |
1986年 | 43篇 |
1985年 | 28篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 16篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1979年 | 23篇 |
1977年 | 12篇 |
1975年 | 17篇 |
1974年 | 18篇 |
1971年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Ordonez Francisco Javier Rosety Manuel Rosety-Rodriguez Manuel 《Clinical journal of sport medicine》2006,16(4):355-356
OBJECTIVE: The present study was designed to determine the influence of a 12-week exercise program on the activity of erythrocyte glutathione peroxidase (GPX) in adolescents with Down syndrome. DESIGN: An interventional study with before-after comparison. SETTING: Sport Medicine School, University of Cadiz (Andalusia, Spain). PATIENTS: Thirty-one male adolescents (16.3+/-1.1) with Down syndrome. None of them suffered acute medical problems at that moment and had not taken part in any physical activity program in the last 6 months. INTERVENTION: A 12-week training program with 3 days per week, consisting of warm up (15 min) followed by a main part (20 to 35 min) at a work intensity of 60% to 75% of peak heart rate (HRmax=194.5-[0.56xage]) and by a cool-down period (10 min). MAIN OUTCOME MEASUREMENT: Erythrocyte activity of GPX. RESULTS: Preexercise and postexercise GPX activity in adolescents with Down syndrome were 24.8+/-3.1 [23.1 to 26.5] U/g hemoglobin and 29.3+/-2.9 [28.1 to 30.5] U/g hemoglobin, respectively. When compared with baseline values it was increased significantly (24.8+/-3.1 vs. 29.3+/-2.9; P=0.011). CONCLUSION: Regular exercise increased significantly GPX activity. Further studies are required to assess the behavior of other antioxidant enzymes to highlight potential benefits of regular exercise in redox metabolism. 相似文献
52.
Javier R Caso María A Moro Pedro Lorenzo Ignacio Lizasoain Juan C Leza 《European neuropsychopharmacology》2007,17(9):600-607
Stress is known to be one of the risk factors of stroke. Most of the knowledge on the effects of stress on cerebrovascular disease in humans is restricted to catecholamines and glucocorticoids effects on blood pressure and/or development of atherosclerosis. However, few experimental studies have examined the possible mechanisms by which stress may affect stroke outcome. We have used an acute stress protocol consisting of the exposure of male Fischer rats to an acute, single exposure immobilisation protocol (6 h) prior to permanent middle cerebral artery occlusion (MCAO), and we have found that stress worsens behavioural and neurological outcomes and increased infarct size after MCAO. The possible regulatory role of the TNFalpha and IL-1beta was studied by looking at the release of these cytokines in brain. The results of the present study showed an increase in IL-1beta release in cerebral cortex after exposure to acute stress. Brain levels of IL-1beta are also higher in previously stressed MCAO rats than in MCAO animals without stress. Pharmacological blockade of IL-1beta with an antibody anti-IL-1beta led to a decrease in the infarct size as well as in neurological and behavioural deficits after MCAO. In summary, our results indicate that IL-1beta, but not TNFalpha, accounts at least partly for the worsening of MCAO consequences in brain of rats exposed to acute stress. 相似文献
53.
Perla A Vargas Pippa M Simpson Margo Bushmiaer Rajiv Goel Craig A Jones James S Magee Charles R Feild Stacie M Jones 《Annals of allergy, asthma & immunology》2006,96(6):787-793
BACKGROUND: Children with poorly controlled asthma are at high risk of airway remodeling, sleep disruption, school absenteeism, and limited participation in activities. OBJECTIVE: To determine asthma prevalence and characterize disease severity and burden in school-aged children. METHOD: A case-finding study was conducted via a multiple-choice questionnaire and asthma algorithm. Items used for analysis include physician diagnosis of asthma, symptom severity, and health care utilization. The chi2 test was used to determine the significance of differences among cases. Logistic regression was used to evaluate the association of patient factors and asthma indicators. RESULTS: Of the 5,417 children surveyed, 1,341 (25%) were classified as being at risk of asthma. Of these asthma cases, 55% were positive by diagnosis and algorithm (active), 10% were positive per algorithm alone (suspected), and 35% were positive per diagnosis alone (nonactive). Only 14% of all asthma cases reported experiencing no respiratory symptoms (< 1% active, 2% suspected, and 40% nonactive) compared with 75% of noncases. Also, 75% of noncases reported never missing school compared with 19%, 33%, and 54% of active, suspected, and nonactive asthma cases. African American race, Medicaid enrollment, and male sex were independent predictors of asthma risk. Similarly, African American race, Medicaid enrollment, age, and persistent asthma were independent predictors of emergency department use among asthma cases. DISCUSSION: Prevalence of active symptoms suggestive of poor asthma control was extremely high among urban, minority children enrolled in Arkansas' largest public school district. Poor asthma control greatly affects quality of life, including school attendance and performance. Interventions should raise expectations and emphasize the importance of achieving asthma control. 相似文献
54.
A case history of a 32-year-old female Olympic pole vaulter is reported. Two months after endoscopic surgery for chronic Achilles tendinopathy, she developed a keloid lesion on the hindfoot area. She was treated with corticosteroids, topical and intralesional injections. A satisfactory result was obtained, and the athlete was able to resume her competitive activity at 5 months after surgery. Keloid pathogenesis, treatment, and prevention are briefly discussed. 相似文献
55.
56.
57.
58.
Alfredo Avellaneda Fernández álvaro Pérez Martín Maravillas Izquierdo Martínez Mar Arruti Bustillo Francisco Javier Barbado Hernández Javier de la Cruz Labrado Rafael Díaz-Delgado Pe?as Eduardo Gutiérrez Rivas Cecilia Palacín Delgado José Ramón Ramón Giménez Javier Rivera Redondo 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(10):e1-e5
59.
Farzan Filsoufi Parwis B Rahmanian Javier G Castillo Eva Karlof Thomas D Schiano David H Adams 《Liver transplantation》2007,13(9):1317-1323
Cardiovascular diseases requiring surgical therapy in patients with prior liver transplantation are rare. Little is known about the outcome of patients with liver allograft undergoing cardiac surgery. Herein we report our experience in this patient population with an emphasis on operative outcomes and mid-term survival. Between January 1998 and December 2004, 12 patients (mean +/- standard deviation age 68 +/- 9 years, 7 [58%] male) with previous liver transplantation who underwent cardiac surgery were identified. Main outcome measures were hospital mortality, postoperative complications, allograft function, and long-term survival. There was no in-hospital mortality. Three major complications (25%) occurred, including 1 each (8%) of respiratory failure, renal failure, and biliary leakage. All complications were resolved by the time of discharge. Allograft dysfunction determined by an increase of liver function parameters was noticed in 4 (33%) and recovered before discharge. The average length of stay in intensive care unit was 72 +/- 45 hours, and the mean length of stay in hospital was 22 +/- 17 days. One- and 5-year survival was 91% +/- 8% and 67% +/- 14%, respectively. Cardiac surgery can be performed safely in liver transplant recipients with extremely low mortality and acceptable morbidities. Allograft dysfunction is a common finding, but it is transient, with early functional recovery. Five-year survival of liver recipients undergoing cardiac procedures is similar to that of the general population undergoing cardiac surgery. Our data suggest that these patients should be considered for cardiac surgery in reference centers with expertise in complex cardiac procedures and perioperative management of these highly specific patients. 相似文献
60.
Hector Rodriguez-Luna Hugo E. Vargas Adyr Moss Kunam S. Reddy Richard B. Freeman David Mulligan 《American journal of transplantation》2005,5(9):2244-2247
The Model for End-Stage Liver Disease (MELD) is used to assign priority for liver transplantation candidates. The Organ Procurement and Transplantation Network (OPTN) approved recognized exceptional diagnoses (RED's) for which MELD fails to accurately measure priority. Centers can request increased MELD points in cases not recognized by this policy (non-RED's). Our aim was to compare regional practices to justify non-RED requests for MELD adjustments. The UNOS/OPTN database was queried to extract all adult cases for which a non-RED MELD adjustment was requested from 2/27/02 until 8/27/03. The data were stratified by region and justification. Data for 29,510 listings were available. 26,947 had complete diagnosis information. There were 827 non-RED requests of which 477 (57.7%) petitions were approved by the regional review boards (RRBs). The approval rate varied significantly among regions (range: 28-75%, p<0.0001). The most common non-RED's were complications of portal hypertension (48%). The percentage of patients listed with non-RED's varied significantly among regions (0.7-8.3 %, p<0.0001), as did the proportion of patients transplanted with non-RED's (2.1-31.9%, p<0.0001). Demographics did not differ among regions requesting non-REDs.Widespread regional variations exist in the handling of requests for non-REDs. These variations point to the need for reform to standard exception criteria. 相似文献