全文获取类型
收费全文 | 5066篇 |
免费 | 494篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 176篇 |
妇产科学 | 116篇 |
基础医学 | 679篇 |
口腔科学 | 74篇 |
临床医学 | 600篇 |
内科学 | 1070篇 |
皮肤病学 | 67篇 |
神经病学 | 490篇 |
特种医学 | 304篇 |
外科学 | 767篇 |
综合类 | 173篇 |
一般理论 | 4篇 |
预防医学 | 421篇 |
眼科学 | 48篇 |
药学 | 239篇 |
中国医学 | 5篇 |
肿瘤学 | 294篇 |
出版年
2023年 | 29篇 |
2022年 | 44篇 |
2021年 | 99篇 |
2020年 | 56篇 |
2019年 | 102篇 |
2018年 | 99篇 |
2017年 | 77篇 |
2016年 | 87篇 |
2015年 | 105篇 |
2014年 | 170篇 |
2013年 | 205篇 |
2012年 | 249篇 |
2011年 | 253篇 |
2010年 | 168篇 |
2009年 | 178篇 |
2008年 | 205篇 |
2007年 | 225篇 |
2006年 | 230篇 |
2005年 | 209篇 |
2004年 | 192篇 |
2003年 | 168篇 |
2002年 | 200篇 |
2001年 | 158篇 |
2000年 | 173篇 |
1999年 | 139篇 |
1998年 | 102篇 |
1997年 | 121篇 |
1996年 | 79篇 |
1995年 | 77篇 |
1994年 | 86篇 |
1993年 | 62篇 |
1992年 | 118篇 |
1991年 | 99篇 |
1990年 | 69篇 |
1989年 | 104篇 |
1988年 | 90篇 |
1987年 | 87篇 |
1986年 | 66篇 |
1985年 | 78篇 |
1984年 | 52篇 |
1983年 | 44篇 |
1982年 | 37篇 |
1981年 | 31篇 |
1980年 | 39篇 |
1979年 | 39篇 |
1978年 | 35篇 |
1977年 | 29篇 |
1976年 | 25篇 |
1974年 | 21篇 |
1973年 | 22篇 |
排序方式: 共有5583条查询结果,搜索用时 0 毫秒
101.
To clarify the mechanisms of afterload reduction on left ventricular diastolic function, the influence of nitroglycerin upon ventricular diastolic pressure-volume relations was studied in 22 patients during catheterization. After nitroglycerin, average ventricular systolic pressure declined by 25 mm Hg (18%) and end-diastolic pressure by 7 mm Hg (28%) (P less than 0.005). End-systolic and diastolic ventricular volumes decreased by 37% and 23% respectively (P less than 0.005). Although peak negative dP/dt fell by 22% (P less than 0.0005), "T", an index of the time course of isovolumic diastolic ventricular relaxation, was insignificantly changed. Diastolic pressure-volume curves were significantly displaced downward and leftward without significant change in slope, suggesting that a family of pressure-volume curves for each ventricle with similar slope but positions depend upon immediate loading conditions. Absence of change in slope or of "T" suggests that this displacement may be mediated indirectly, perhaps by relaxation of extracardiac constraints to ventricular distensibility. Accordingly, improvement in ventricular function by vasodilators may be partly due to downward displacement of the pressure-volume relation, with associated reduction of wall tension and myocardial oxygen consumption. 相似文献
102.
Factors influencing the development of Barrett's epithelium in the esophageal remnant postesophagectomy 总被引:5,自引:0,他引:5
O'Riordan JM Tucker ON Byrne PJ McDonald GS Ravi N Keeling PW Reynolds JV 《The American journal of gastroenterology》2004,99(2):205-211
BACKGROUND: Barrett's esophagus results from chronic reflux of both acid and bile. Reflux of gastric and duodenal contents is facilitated through the denervated stomach following esophagectomy, but the development of Barrett's changes in this model and the relationship to gastric and esophageal physiology is poorly understood. AIMS: To document the development of new Barrett's changes, i.e., columnar metaplasia or specialized intestinal metaplasia (SIM) above the anastomosis, and relate this to the recovery of gastric acid production, acid and bile reflux, manometry, and symptoms. PATIENTS AND METHODS: Forty-eight patients at a median follow-up of 26 months (range = 12-67) postesophagectomy underwent endoscopy with biopsies taken 1-2 cm above the anastomosis. The indication for esophagectomy had been adenocarcinoma (n = 27), high-grade dysplasia (n = 2), and squamous cell cancer (n = 19). Physiology studies were performed in 27 patients and included manometry (n = 25), intraluminal gastric pH (n = 24), as well as simultaneous 24-hour esophageal pH (n = 27) and bile monitoring (n = 20). RESULTS: Duodenogastric reflux increased over time, with differences between patients greater than and less than 3 years postesophagectomy for acid (p = 0.04) and bile (p = 0.02). Twenty-four patients (50%) developed columnar metaplasia and of these 13 had SIM. The prevalence of columnar metaplasia did not relate to the magnitude of acid or bile reflux, to preoperative neoadjuvant therapies, or to the original tumor histology. The duration of reflux was most significant, with increasing prevalence over time, with SIM in 13 patients at a median of 61 months postesophagectomy compared with 20 months in the 35 patients who were SIM-negative (p < 0.006). Supine reflux correlated with symptoms. CONCLUSIONS: The development of Barrett's epithelium is frequent after esophagectomy, is time-related, reflecting chronic acid and bile exposure, and is not specific for adenocarcinoma or the presence of previous Barrett's epithelium. This model may represent a useful in vivo model of the pathogenesis of Barrett's metaplasia and tumorigenesis. 相似文献
103.
Zweig RA Siegel L Hahn S Kuslansky G Byrne K Fyffe D Passman V Stewart D Hinrichsen GA 《Gerontology & geriatrics education》2005,25(4):109-129
Most older adults diagnosed with a mental disorder receive treatment in primary care settings that lack personnel skilled in geropsychological diagnosis and treatment. The Ferkauf Older Adult Program of Yeshiva University endeavors to bridge this gap by providing training in geriatric psychology, through coursework and diverse clinical practica, to clinical psychology doctoral students within a large urban professional psychology program. In an innovative effort to provide the most disadvantaged elderly with comprehensive mental health treatment and maximize trainee exposure to an interdisciplinary treatment model, the program also pairs selected doctoral psychology trainees with medical residents to optimize integrated mental health service delivery for primary care elderly. The program has the following core objectives: (1) Infuse the mental health and aging knowledge base into the regular graduate curriculum; (2) Provide interdisciplinary training in geropsychological diagnostic and consultative services within an urban primary care setting; (3) Provide interdisciplinary training in the practice of psychological and neuropsychological evaluation of elderly; (4) Provide training in geropsychological psychotherapeutic intervention, including individual, couples/family, and brief/psycho-educational therapies with outpatient older adults. These objectives are achieved by pooling the resources of a graduate school of psychology, a local public hospital, and an academic medical center to achieve educational and clinical service goals. 相似文献
104.
Two patients with acute Wemicke's encephalopathy, with the diagnosis confirmed pathologically at autopsy, showed substantial vacuolation and neuronal degeneration in discrete nuclei of the thalamus. Thalamic vacuolation has not been described previously in acute Wernicke's encephalopathy. The use of frozen sections to minimize processing artifact was fundamental in demonstrating this pathology. The pathogenic mechanism underlying this change appears to be different to that seen in the more typical periventricular, mamillary body and brainstem lesions. We hypothesize that a specific neural pathway may be involved and suggest that this pathway could be the ascending nitric oxide-containing cholinergic pathway from the brainstem. 相似文献
105.
Byrne JG Karavas AN Adams DH Aklog L Aranki SF Filsoufi F Cohn LH 《The Journal of heart valve disease》2001,10(5):584-590
BACKGROUND AND AIM OF THE STUDY: An alternative to avoid redo sternotomy in patients with patent left internal mammary artery-left anterior descending coronary artery (LIMA-LAD) grafts undergoing mitral valve surgery is right thoracotomy with moderate-deep hypothermia (approximately 20 degrees C) and fibrillatory arrest without aortic cross-clamping. Few reports exist which directly compare re-sternotomy and right thoracotomy. METHODS: Between July 1992 and February 2000, 47 patients (39 males, eight females; median age 66 years; range: 41-83 years; 41 in NYHA class III or IV) with patent LIMA-LAD grafts underwent mitral valve surgery. Thirty-seven patients were approached through a right thoracotomy with moderate-deep hypothermia (median 20 degrees C) and fibrillatory arrest (right thoracotomy group), and 10 were approached through a re-sternotomy, with aortic cross-clamping and cardioplegic arrest. The median ejection fraction was 42% (range: 20-71%). Univariate analysis was used to determine predictors of outcome, as well as to evaluate differences in characteristics between groups. RESULTS: Operative mortality (OM) and perioperative myocardial infarction for the entire cohort was 11% and 10%, respectively, and there were no inter-group differences. No preoperative characteristics were associated with OM. Two LIMA-LAD graft injuries occurred in the re-sternotomy group compared with none in the right thoracotomy group (20% versus 0%, p = 0.04). Transfusion requirements were also greater in the redo sternotomy group (median 7 versus 2 packed red blood cell units, p = 0.04). CONCLUSION: Right thoracotomy with moderate-deep hypothermia and fibrillatory arrest is the preferred approach for reoperative mitral valve surgery after coronary artery bypass grafting in the presence of patent LIMA-LAD grafts. These data suggest that this approach is associated with decreased incidence of LIMA-LAD graft injury, as well as reduced transfusion requirements. 相似文献
106.
107.
108.
109.
A.?Faundez F.?Byrne C.?Sylvestre V.?Lafage A.?Cogniet Jean-Charles?Le HuecEmail author 《European spine journal》2015,24(1):42-48
Purpose
Pedicle subtraction osteotomy is a well-described surgical technique for treatment of kyphotic deformity in the spine. It is not widely used for treatment of thoracic kyphosis. We present the first documented series of 28 patients who underwent this procedure in 3 international centers. These patients presented with severe deformity with a wide range of aetiologies.Indications
Kyphosis larger than 70 degrees, which is demonstrably rigid based on dynamic imaging.Materials and methods
28 patients underwent surgery following pre-op neurological and radiographic assessment to fully assess the deformity. A triangular osteotomy was carried out using intraoperative navigation techniques. The patients were assessed post-operatively again with clinical and radiographic parameters at regular follow-up.Results
The mean ODI score after surgery was 24.7 (16–42) while the pre-op was 53.4 (38–76). Mean thoracic kyphosis was improved from 64.2° (±20.1°) to 41.1° (±17.4°) resulting in a mean sagittal correction of 23.1°. Mean segmental correction at the PSO for all 28 cases was 17.8° (±8.1°). Stratified by region we found different values for the PSO correction: between T1 and T5 (6 cases) it was 17.5° (±5.4°) and between T6 and T9 (4 cases) 18.2° (±4.7°) and between T10 and L1 (18 cases) 26.2° (±5.2°). FBI index was 22.3° pre-op and improved to 7.8° post-op. Calculations were performed with Microsoft excel (2011 Microsoft, Redmond, WA).Conclusions
Global sagittal balance was statistically improved in this series as demonstrated by FBI and C7 SVA correction.110.
This study investigated the relationship between stress and body satisfaction in adolescence. A sample consisting of 515 adolescents aged 12–16 years completed a series of self‐report questionnaires assessing general and specific aspects of adolescent stress, body satisfaction and the psychological constructs of self‐esteem, depressive symptoms and body importance. Results revealed a significant association between higher body dissatisfaction and higher ratings of peer stress, lower self‐esteem and greater body importance for female and male adolescents. These findings suggest that adolescent stress relates to satisfaction with the body and that this stress is specifically focused on the peer environment for both genders during adolescence. This may have implications for intervention programmes aimed at improving body satisfaction, suggesting that the inclusion of stress management training in these programmes could specifically focus on difficulties within the peer domain. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献