全文获取类型
收费全文 | 2706篇 |
免费 | 160篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 88篇 |
妇产科学 | 46篇 |
基础医学 | 280篇 |
口腔科学 | 88篇 |
临床医学 | 168篇 |
内科学 | 548篇 |
皮肤病学 | 67篇 |
神经病学 | 435篇 |
特种医学 | 202篇 |
外科学 | 600篇 |
综合类 | 32篇 |
一般理论 | 1篇 |
预防医学 | 41篇 |
眼科学 | 61篇 |
药学 | 102篇 |
中国医学 | 1篇 |
肿瘤学 | 63篇 |
出版年
2023年 | 22篇 |
2022年 | 35篇 |
2021年 | 81篇 |
2020年 | 53篇 |
2019年 | 60篇 |
2018年 | 65篇 |
2017年 | 60篇 |
2016年 | 83篇 |
2015年 | 97篇 |
2014年 | 113篇 |
2013年 | 149篇 |
2012年 | 185篇 |
2011年 | 172篇 |
2010年 | 99篇 |
2009年 | 106篇 |
2008年 | 189篇 |
2007年 | 189篇 |
2006年 | 184篇 |
2005年 | 168篇 |
2004年 | 143篇 |
2003年 | 121篇 |
2002年 | 138篇 |
2001年 | 47篇 |
2000年 | 46篇 |
1999年 | 37篇 |
1998年 | 21篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1992年 | 23篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 10篇 |
1988年 | 13篇 |
1987年 | 21篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1971年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有2874条查询结果,搜索用时 15 毫秒
61.
62.
Ercan Erdogan Mehmet Akkaya Ahmet Bacaksiz Abdurrrahman Tasal Osman S?nmez Mehmet Ali Elbey Seref Kul Mehmet Akif Vatankulu Murat Turfan ?mer G?ktekin 《Clinics (S?o Paulo, Brazil)》2013,68(10):1333-1337
OBJECTIVE:
Successful revascularization of chronic total occlusions has been associated with improved left ventricular systolic function, reduced anginal symptoms, increased exercise capacity, and increased survival. This study was conducted to determine the impact of revascularization in chronic total occlusion on left ventricular function using novel echocardiographic techniques.METHODS:
A total of 129 patients with chronic total occlusion who underwent revascularization between April 2011 and November 2012 were included in this study. Echocardiographic assessments with two-dimensional speckle tracking echocardiography and real-time three-dimensional echocardiography were performed before the procedure and one month after the procedure. The left ventricular ejection fraction, left ventricular volumes, and three-dimensional systolic dyssynchrony index were quantified.RESULTS:
An immediate procedural success was obtained in 118 patients (91.5%). There were no acute or subacute stent thromboses during follow-up. The mean left ventricular ejection fraction significantly increased (p<0.001), while the left ventricular end-diastolic and end-systolic volumes significantly decreased (p = 0.001 and p<0.001, respectively). The three-dimensional systolic dyssynchrony index also decreased significantly (p<0.001). The global longitudinal strain showed a significant increase after successful revascularization (p<0.001). An increase in the global longitudinal strain was correlated with an increase in the left ventricular ejection fraction (r = 0.27, p = 0.02). The patients with a left ventricular ejection fraction ≥50% displayed a greater improvement in the global longitudinal strain, and the patients with diabetes showed less improvement.CONCLUSIONS:
Using novel echocardiographic techniques, our results showed that restoring the coronary blood flow in chronic total occlusion patients reduces the left ventricular volumes and improves the left ventricular ejection fraction and the global longitudinal strain of hibernating myocardium. 相似文献63.
Ahmet Bacaksiz Mehmet Akif Vatankulu Mehmet Kayrak Hasan Huseyin Telli Selim S. Ayhan Osman Sonmez Ayse Alp Sadik Buyukbas 《Clinics (S?o Paulo, Brazil)》2013,68(7):997-1003
OBJECTIVES:
Acute ST-elevation myocardial infarction is associated with ventricular dysfunction due to ischemia-induced progressive myocardial damage. The decrease in ventricular compliance causes left atrial dilatation and stretching of the atrial myocardium, which are the main stimuli for the secretion of atrial natriuretic peptide. The aim of this study was to evaluate left atrial dimensions and atrial natriuretic peptide levels in patients early after their first acute ST-elevation myocardial infarction and assess the probable interaction between coronary lesions and these measurements.METHODS:
A total of 110 patients with acute myocardial infarction and 50 controls were studied. Plasma atrial natriuretic peptide was measured at admission. Left ventricular function, diameter, and volume index were evaluated using transthoracic echocardiography. Gensini and vessel scores of the patients who underwent coronary angiography were calculated.RESULTS:
Plasma atrial natriuretic peptide in the patients with myocardial infarction was increased compared with that in controls (3.90±3.75 vs. 1.35±0.72 nmol/L, p<0.001). Although the left atrial diameter was comparable in patients and controls, the left atrial volume index was increased in patients with acute myocardial infarction (26.5±7.1 vs. 21.3±4.9 mL/m2, p<0.01). Multivariate regression analysis showed a strong independent correlation between the left atrial volume index and the plasma atrial natriuretic peptide level (β = 0.23, p = 0.03).CONCLUSIONS:
The left atrial volume index and plasma atrial natriuretic peptide level were correlated in patients with acute myocardial infarction. 相似文献64.
Binali Çakur DDS PhD Muhammed Akif Sümbüllü DDS PhD Doğan Durna DDS 《Clinical implant dentistry and related research》2013,15(1):83-87
Background: Osseo‐integrated implants are increasingly being used to restore functional dentition; however, in the posterior region, implant placement can be problematic because of inadequate bone height. In this condition, maxillary sinus floor elevation surgery has become the treatment of choice. The presence of anatomic variations within the maxillary sinus such as Underwood's septa and thin schneiderian membrane decreases the success of the sinus floor elevation. Purpose: In this study, we tried to determine the relationship between the anatomic variations of the maxillary sinus: Underwood's septa, schneiderian membrane thickness, and the cortical thickness of the inferior border of the maxillary sinus. Material and Methods: The left and right maxillary sinus images of 74 patients were obtained by using dental computed tomography (CT). The schneiderian membrane and the cortical thickness of the inferior border of the maxillary sinus were measured on the coronal images of dental CT scans at the deepest portion of the sinus cavity. The presence of Underwood's septa was identified on the axial images. The correlations between these variables were assessed. Results: We found that there was only a negative correlation between the schneiderian membrane thickness and the presence of Underwood's septa (r = –0.168 p = .042). Conclusion: It is suggested that Underwood's septa may be the reason for the thinness of the schneiderian membrane. However, future studies among larger groups are necessary for confirming the finding by using well‐designed clinical studies. 相似文献
65.
66.
The aim of this clinical trial was to evaluate the pulsatile perfusion mode in pediatric patients who had complex cardiac pathologies according to Jenkins stratifications (category 4) undergoing cardiopulmonary bypass procedures (CPB). Patients with transposition of great arteries (TGA) and ventricular septal defect (VSD) were included in this clinical study. Eighty‐nine consecutive pediatric patients undergoing open heart surgery for repair of TGA‐VSD were prospectively entered into the study and were randomly assigned to either the pulsatile perfusion group (Group P, n = 58) or the nonpulsatile perfusion group (Group NP, n = 31). There were no differences between groups in terms of demographical and intraoperative parameters. The pulsatile group needed significantly less inotropic support (P < 0.05) and had lower lactate levels (P < 0.001), higher urine output (P < 0.01), and higher albumin levels (P < 0.05). In addition, the pulsatile group had less ICU (P < 0.01) and hospital stays (P < 0.001). We conclude that the use of pulsatile flow is a better option and should be considered for repair of the complex congenital heart defects. 相似文献
67.
Until recently, risk scoring systems for adult patients consisted of only clinical criteria. Currently, we are experiencing an abundant surge of literature integrating a wide range of biomarker arrays to clinical criteria in assessing the risk in an adult. In fact, novel risk scoring systems such as Reynolds criteria have emerged by combining the validated biomarkers to the traditional risk factors. Novel biomarkers potentially improve clinical management of cardiovascular disease, but there are gaps in understanding their role during childhood. The reason might be related to relatively lower prevalence of cardiovascular disease in children compared to the adult population. One exceptional group is the children with congenital heart disease. Recent studies indicate that novel biomarkers can alert the clinician in a timely manner about neurological and myocardial injury and their inflammatory consequences. Current technologies enable us to measure several biomarkers using only a few microliters of plasma. The preliminary studies show that novel biomarkers in addition to the traditionally studied biomarkers can help the clinician to identify children at high risk following pediatric heart surgery. Future studies are needed to confirm the role of biomarkers in monitoring children after cardiopulmonary bypass. 相似文献
68.
Berker D Karabulut H Isik S Tutuncu Y Ozuguz U Erden G Aydin Y Dagli M Guler S 《Endocrine》2012,41(1):116-121
Hearing loss has commonly been reported in association with thyroid disorders and during treatment with propylthiouracil. The relationship between hyperthyroidism and the auditory system has not been previously investigated. The aim of this cross-sectional, case-control study was to investigate hearing loss in patients with Graves' disease (GD). The study population consisted of patients with newly diagnosed GD and healthy controls. Pure tone audiometry at frequencies of 250, 500, 1000, 2000, 4000 and 8000 Hz, along with immittance measures including tympanometry and acoustic reflex tests, were performed in all participants. Twenty-two GD patients and 22 healthy controls consented to inclusion in the study. The differences between groups with regards to age and gender distribution were statistically insignificant (P = 0.567 and P = 0.757, respectively). The hearing thresholds of right and left ears were also similar in both groups (P > 0.05). When single-ear evaluations were taken into account (total of 44 ears for both groups), hearing thresholds in the GD group were significantly higher than healthy controls at all frequencies (P < 0.05). Following testing at the designated frequencies, the only significant effect of thyrotoxicosis was observed with frequencies of 4000 and 8000 Hz. The odds ratio for having hearing loss at a frequency of 8000 HZ associated with GD was 14.97 (95% confidence interval 4.03-55.64). In patients with GD, right and left pure tone audiometric findings at a frequency of 8000 Hz correlated positively with FT3, FT4 and negatively with TSH. Our results are highly suggestive of a decrease in hearing ability in patients with GD, particularly at high frequencies. Further studies are needed to help elucidate the mechanisms behind hearing loss which develops in association with GD. 相似文献
69.
70.
Tufan A Engin Tezcan M Kaya A Mercan R Oner Y Ozturk MA 《Modern rheumatology / the Japan Rheumatism Association》2012,22(5):774-777
Aortitis, inflammation of the aortic tissue, is most commonly caused by vasculitic rheumatic conditions, and less frequently infectious organisms. Involvement of the aorta is well defined in HLA-B27-associated spondyloarthropathies such as long-standing ankylosing spondylitis and Reiter's syndrome. However, unlike other spondyloarthropathies, aortic involvement or true aortitis is not a feature of psoriatic arthritis and has been reported in only a few cases. Herein, we report the case of a 22?year-old woman with psoriatic arthritis who developed descending aortitis while using tumor necrosis factor inhibitors. 相似文献