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   2105篇
  免费   129篇
耳鼻咽喉   19篇
儿科学   49篇
妇产科学   26篇
基础医学   210篇
口腔科学   19篇
临床医学   297篇
内科学   343篇
皮肤病学   19篇
神经病学   255篇
特种医学   48篇
外科学   199篇
综合类   46篇
一般理论   3篇
预防医学   402篇
眼科学   16篇
药学   203篇
中国医学   2篇
肿瘤学   78篇
  2023年   13篇
  2022年   25篇
  2021年   44篇
  2020年   25篇
  2019年   33篇
  2018年   47篇
  2017年   38篇
  2016年   38篇
  2015年   45篇
  2014年   73篇
  2013年   87篇
  2012年   152篇
  2011年   161篇
  2010年   93篇
  2009年   71篇
  2008年   158篇
  2007年   148篇
  2006年   144篇
  2005年   160篇
  2004年   150篇
  2003年   129篇
  2002年   106篇
  2001年   58篇
  2000年   31篇
  1999年   29篇
  1998年   17篇
  1997年   7篇
  1996年   9篇
  1995年   16篇
  1994年   11篇
  1993年   6篇
  1992年   9篇
  1991年   5篇
  1990年   12篇
  1989年   19篇
  1988年   17篇
  1987年   14篇
  1986年   6篇
  1985年   4篇
  1984年   4篇
  1983年   5篇
  1982年   4篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有2234条查询结果,搜索用时 15 毫秒
21.
The purpose of this study is to assess the sensitivity and specificity of magnetic resonance imaging (MRI) in the diagnosis of anterolateral impingement of the ankle and to assess the most helpful sequence in making the diagnosis. Twenty-four patients who had undergone ankle arthroscopy were chosen. Twelve patients had arthroscopically documented anterolateral impingement, and 12 patients with no impingement on arthroscopy served as controls. Two musculoskeletal radiologists and an orthopedic surgeon, blinded to the operative diagnosis, retrospectively reviewed selective MRI images in the sagittal, axial, and coronal planes. The sensitivities and specificities were calculated for all 3 reviewers. The Kendall coefficient of concordance was calculated for overall agreement among reviewers. Sensitivities varied from 0.75 to 0.83, whereas specificities varied from 0.75 to 1.00. Using the Fisher exact test of contingency, the sensitivities and specificities showed that all reviewers' interpretations were statistically significant with P = .039, .001, and .012, respectively. The axial images were felt to be most helpful in making the diagnosis. The physicians felt that the sagittal images were helpful in 67%, 83%, and 100%, respectively. MRI is a useful tool that can aid the clinician in the diagnosis of anterolateral impingement of the ankle. T1 sagittal images demonstrating displacement of the normal fat signal anterior to the fibula by scar can be useful and help to confirm the diagnosis.  相似文献   
22.

Aims

Rhabdomyosarcoma (RMS) is the most common soft tissue tumor of childhood. Patient age, size, histologic finding, and site of the tumor are primary determinants of prognosis in RMS. Chest wall RMS is a site in which the limitations of surgical excision are realized. We aim to determine the impact of surgical excision in chest wall RMS.

Methods

A retrospective chart review was conducted of all 130 pediatric patients enrolled in the Intergroup Rhabdomyosarcoma Study (IRS) with chest wall rhabdomyosarcoma from the first (I) through fourth (IV) IRS with follow-up to June 2005. Median follow-up was 12.1 years (4.6-27.2 years).

Results

There was a significant improvement in failure-free survival (FFS) and overall survival (OS) between the first IRS study, I, and IRS-IV. The estimated FFS and OS at 5 years in IRS I was 30% and 40%, respectively, compared to 68% and 78%, respectively, in IRS-IV (P = .03 and P = .05, respectively). There was no association between histologic finding or size and FFS or OS. However, all patients who presented without metastasis had an FFS and OS of 49% and 61%, respectively, compared with metastatic patients, 7% and 7%, respectively (P < .001). Five-year FFS of group I, II, and III patients was 52%, 52%, and 45%, respectively, and OS was 65%, 60%, and 59%, respectively. There was no significant difference in 5-year FFS or OS in patients who had a complete resection (group I), complete resection with positive microscopic margins (group II), or biopsy or partial resection only (group III). In groups I to III patients, the local and regional failure rate at 5 years is 25% and 6%, respectively.

Conclusions

The most significant impact on outcome in chest wall RMS patients is metastatic disease at diagnosis. The locoregional failure rate is high but does not appear to impact survival. Alternative treatment strategies are needed for chest wall RMS, but aggressive surgical excision may not be necessary.  相似文献   
23.
Use of the novel marker BLCA-1 for the detection of bladder cancer   总被引:2,自引:0,他引:2  
PURPOSE: Bladder cancer specific nuclear structural alterations have been identified. We examined the expression pattern of one of these proteins, BLCA-1, in tissue and urine samples from individuals with bladder cancer as well as in samples from normal controls. MATERIALS AND METHODS: BLCA-1 sequence data were used to produce antibodies to this protein, which were used in immunoblot and enzyme-linked immunosorbent assays. RESULTS: BLCA-1 was detectable in tissue from patients with bladder cancer but not in normal adjacent areas of the bladder or in normal donor bladder tissue. This protein was also detectable in the urine of patients with bladder cancer by immunoblot and immunoassay. Using a cutoff of 0.025 optical density units (absorbance value) BLCA-1 was detected in 20 of 25 urine samples from patients with bladder cancer but in only 6 of 46 normal, high risk, prostate or renal cancer samples tested, resulting in a test with 80% sensitivity and 87% specificity. Expression of this protein did not appear to correlate with tumor grade. CONCLUSIONS: This research indicates that BLCA-1 is a urine based marker of bladder cancer which may be useful for the detection of this disease.  相似文献   
24.
OBJECTIVE: Pulmonary vein isolation is curative in selected patients with atrial fibrillation. The objective of this study was to assess the feasibility and safety (midterm results) of video-assisted thoracoscopic epicardial pulmonary vein isolation. METHODS: Twenty-seven patients (22 male patients) with atrial fibrillation (18 paroxysmal, 4 persistent, and 5 permanent; average age, 57 years) underwent bilateral video-assisted thoracoscopic off-pump epicardial pulmonary vein isolation and exclusion of the left atrial appendage. All patients had had unsuccessful drug therapy or were intolerant to antiarrhythmic drug therapy or were intolerant to warfarin. The approach included two 10-mm ports and one 5-cm working port (non-rib spreading) bilaterally. Pulmonary vein isolation was achieved bilaterally by using a bipolar radiofrequency device. The left atrial appendage was excised with a surgical stapler. RESULTS: Bilateral pulmonary vein isolation and left atrial appendage excision was performed successfully in all patients. There were no conversions to sternotomy or thoracotomy. All patients were extubated in the operating room. Postoperative complications in 3 patients were minor and resolved within 48 hours. One morbidly obese patient had more serious complications related to comorbid conditions. Average postoperative follow-up is approximately 6 months (173.6 days). Twenty-three patients have been followed up for greater than 3 months, and 21 of these patients are free of atrial fibrillation (91.3%). The results of magnetic resonance angiography were normal (no pulmonary vein stenosis) in 12 of 12 patients evaluated 3 to 6 months postoperatively. CONCLUSIONS: Bilateral video-assisted thoracoscopic pulmonary vein isolation with excision of the left atrial appendage is feasible and safe and offers a promising, new, minimally invasive, beating-heart approach for curative surgical treatment of atrial fibrillation.  相似文献   
25.

Purpose

The aim of this study is to determine if there has been a true, absolute, or apparent relative increase in congenital diaphragmatic hernia (CDH) survival for the last 2 decades.

Method

All neonatal Bochdalek CDH patients admitted to an Ontario pediatric surgical hospital during the period when significant improvements in CDH survival was reported (from January 1, 1992, to December 31, 1999) were analyzed. Patient characteristics were assessed for CDH population homogeneity and differences between institutional and vital statistics-based population survival outcomes. SAS 9.1 (SAS Institute, Cary, NC) was used for analysis.

Result

Of 198 cohorts, demographic parameters including birth weight, gestational age, Apgar scores, sex, and associated congenital anomalies did not change significantly. Preoperative survival was 149 (75.2%) of 198, whereas postoperative survival was 133 (89.3%) of 149, and overall institutional survival was 133 (67.2%) of 198. Comparison of institution and population-based mortality (n = 65 vs 96) during the period yielded 32% of CDH deaths unaccounted for by institutions. Yearly analysis of hidden mortality consistently showed a significantly lower mortality in institution-based reporting than population.

Conclusion

A hidden mortality exists for institutionally reported CDH survival rates. Careful interpretation of research findings and more comprehensive population-based tools are needed for reliable counseling and evaluation of current and future treatments.  相似文献   
26.
目的研究12岁以下年幼低常儿童眼散光的分布规律。主要类型及与弱视的关系。方法对门诊4~12岁视力低常儿童829例1349只眼散光进行统训分析。结果复性远视散光最多占57.60%,其他依次为复性近视散光30.62%,混合散光8.15%,单纯远视散光2.22%,单纯近视散光1.41%。散光程度以0.5DC~1.00DC为主,占56.12%,其次为1.25DC~2.00DC占25.72%,2.25DC~3.00D占10.16%,〉3.00DC者占8.01%。顺规散光占94.81%,逆规散光占3.93%,斜向散光占1.26%。矫正视力≥0.9者占52.34%,矫正视力〈0.9者占47.66%。结论复性远视散光是学龄前儿童散光的主要类型,散光与弱视的形成有关。应合理矫正儿童眼散光。  相似文献   
27.
28.
29.
30.
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