全文获取类型
收费全文 | 4409篇 |
免费 | 262篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 78篇 |
妇产科学 | 56篇 |
基础医学 | 426篇 |
口腔科学 | 196篇 |
临床医学 | 429篇 |
内科学 | 1694篇 |
皮肤病学 | 20篇 |
神经病学 | 196篇 |
特种医学 | 244篇 |
外科学 | 441篇 |
综合类 | 99篇 |
一般理论 | 2篇 |
预防医学 | 377篇 |
眼科学 | 114篇 |
药学 | 155篇 |
中国医学 | 4篇 |
肿瘤学 | 142篇 |
出版年
2023年 | 22篇 |
2022年 | 20篇 |
2021年 | 71篇 |
2020年 | 31篇 |
2019年 | 74篇 |
2018年 | 119篇 |
2017年 | 54篇 |
2016年 | 62篇 |
2015年 | 86篇 |
2014年 | 143篇 |
2013年 | 190篇 |
2012年 | 281篇 |
2011年 | 306篇 |
2010年 | 206篇 |
2009年 | 160篇 |
2008年 | 269篇 |
2007年 | 319篇 |
2006年 | 238篇 |
2005年 | 253篇 |
2004年 | 240篇 |
2003年 | 219篇 |
2002年 | 193篇 |
2001年 | 62篇 |
2000年 | 54篇 |
1999年 | 44篇 |
1998年 | 78篇 |
1997年 | 63篇 |
1996年 | 35篇 |
1995年 | 26篇 |
1994年 | 35篇 |
1993年 | 42篇 |
1992年 | 39篇 |
1991年 | 38篇 |
1990年 | 43篇 |
1989年 | 34篇 |
1988年 | 44篇 |
1987年 | 36篇 |
1986年 | 36篇 |
1985年 | 42篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 32篇 |
1981年 | 19篇 |
1980年 | 24篇 |
1978年 | 27篇 |
1977年 | 24篇 |
1975年 | 18篇 |
1973年 | 19篇 |
1969年 | 18篇 |
1968年 | 18篇 |
排序方式: 共有4695条查询结果,搜索用时 62 毫秒
41.
WG Mitchell H Lynn JF Bale MA Maeder SM Donfield B Garg AH Tilton JK Willis TP Bohan 《Pediatrics》1997,100(5):817-824
BACKGROUND: Boys and young men with hemophilia treated with factor infusions before 1985 had a substantial risk of acquiring the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome. This study was designed to assess the effects of HIV and hemophilia per se on neurological function in a large cohort of subjects with hemophilia, and to investigate the relationships between neurological disease and death during follow-up. METHODS: Three hundred thirty-three boys and young men (207 HIV seropositive and 126 HIV seronegative) were evaluated longitudinally in a multicenter, multidisciplinary study. Neurological history and examination were conducted at baseline and annually for 4 years. The relationship between neurological variables, HIV serostatus, CD4+ cell counts, and vital status at the conclusion of the study was examined using logistic regression models. RESULTS: The risks of nonhemophilia-associated muscle atrophy, behavior change, and gait disturbance increased with time in immune compromised HIV-seropositive subjects compared with HIV seronegative or immunologically stable HIV-seropositive subjects. The risk of behavior change in immune compromised HIV-seropositive hemophiliacs, for example, rose to 60% by year 4 versus 10% to 17% for the other study groups. Forty-five subjects (13.5%), all of whom were HIV seropositive, died by year 4. Subjects who died had had increased risks of hyperreflexia, nonhemophilia-associated muscle atrophy, and behavior change. CONCLUSIONS: These results indicate that immune compromised, HIV-seropositive hemophiliacs have high rates of neurological abnormalities over time and that neurological abnormalities were common among subjects who later died. By contrast, immunologically stable HIV-seropositive subjects did not differ from the HIV-seronegative participants. Hemophilia per se was associated with progressive abnormalities of gait, coordination, and motor function. 相似文献
42.
43.
Aronowitz ER Ganley TJ Goode JR Gregg JR Meyer JS 《The American journal of sports medicine》2000,28(2):168-175
The purpose of this study was to evaluate anterior cruciate ligament reconstructions performed in adolescents with open physes and a skeletal age of at least 14 years. At one center, from 1992 to 1996, 19 adolescents (ages, 11 to 15 years) with open physes and a skeletal age of at least 14 years underwent arthroscopic anterior cruciate ligament reconstruction using an Achilles tendon allograft placed through drill holes across the open physes in both the distal femur and proximal tibia. Fifteen patients returned for reevaluation at an average of 25 months postoperatively (range, 12 to 60 months); the remaining four patients were interviewed by telephone. There were no significant leg-length discrepancies or angular deformities as determined by scanograms and anteroposterior and lateral radiographs of the femur and tibia. The mean Lysholm knee score was 97 (range, 94 to 100) and the mean KT-1000 arthrometer side-to-side difference at 20 pounds of anterior force was 1.7 mm (range, 0.0 to 3.0). All patients were satisfied with the results of surgery, and 16 of 19 patients returned to the same sport they were participating in before the injury. This study demonstrates that anterior cruciate ligament reconstruction using an Achilles tendon allograft is a viable treatment option for skeletally immature patients with a skeletal age of 14 years who have sustained midsubstance tears of the anterior cruciate ligament. 相似文献
44.
Fitzpatrick R. Norquist J.M. Jenkinson C. Reeves B.C. Morris R.W. Murray D.W. Gregg P.J. 《Quality of life research》2004,13(2):331-338
The purpose of this study was to examine whether there are advantages in terms of outcome assessment of using Rasch methods of scoring the 12-item Oxford Hip Score (OHS) questionnaire over conventionally Likert scores. As part of a prospective cohort study of total hip replacements in five former regions of England the OHS was sent to patients pre-operatively, at 3 months and 1 year post-operatively. Post-operative data was collected on over 5000 cases. Based on the level of satisfaction with surgery, patients were divided into satisfied and dissatisfied. Analyses were performed to test the relative precision (RP) of Rasch scoring vs. conventionally Likert scores in discriminating the groups experiencing different level of satisfaction. Considerable gains in precision were achieved with Rasch scoring methods when groups were compared 3 and 12 months post-operatively. The results from the current study suggest that in some situations there may be substantial gains in measuring health related outcomes using Rasch-based scoring methods. 相似文献
45.
46.
47.
Usefulness of left ventricular strain analysis in patients with takotsubo syndrome during acute phase
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
48.
Olayinka Afolabi‐Brown M.D. Christian Witzke M.D. Raul Moldovan M.D. Gregg Pressman M.D. 《Echocardiography (Mount Kisco, N.Y.)》2014,31(2):E52-E54
Anomalous right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital coronary anomaly that has an incidence of 0.002%. We report a case of a previously healthy female who presented to our hospital with pneumonia and was incidentally discovered to have ARCAPA. This was initially diagnosed on echocardiography by the unusual echocardiographic finding of multiple color flow Doppler signals around the right ventricular free wall and apex which were subsequently confirmed by angiography to be due to extensive collateral circulation between the left and right coronary arteries. This represents an unusual echocardiographic manifestation of this very rare condition. 相似文献
49.
Mahesh V. Madhavan Bernard J. Gersh Karen P. Alexander Christopher B. Granger Gregg W. Stone 《Journal of the American College of Cardiology》2018,71(18):2015-2040
Coronary artery disease (CAD) is a major cause of morbidity and mortality in patients ≥80 years of age. Nonetheless, older patients have typically been under-represented in cardiovascular clinical trials. Understanding the pathophysiology, epidemiology, and optimal means of diagnosis and treatment of CAD in older adults is crucial to improving outcomes in this high-risk population. A patient-centered approach, taking into account health status, functional ability and frailty, cognitive skills, and patient preferences is essential when caring for older adults with CAD. The present systematic review focuses on the current knowledge base, gaps in understanding, and directions for future investigation pertaining to CAD in patients ≥80 years of age. 相似文献