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   2554篇
  免费   179篇
  国内免费   24篇
耳鼻咽喉   31篇
儿科学   48篇
妇产科学   17篇
基础医学   320篇
口腔科学   82篇
临床医学   203篇
内科学   575篇
皮肤病学   78篇
神经病学   294篇
特种医学   113篇
外科学   506篇
综合类   14篇
预防医学   56篇
眼科学   38篇
药学   133篇
中国医学   1篇
肿瘤学   248篇
  2023年   55篇
  2022年   92篇
  2021年   150篇
  2020年   67篇
  2019年   108篇
  2018年   95篇
  2017年   83篇
  2016年   87篇
  2015年   116篇
  2014年   131篇
  2013年   123篇
  2012年   183篇
  2011年   180篇
  2010年   106篇
  2009年   90篇
  2008年   133篇
  2007年   129篇
  2006年   111篇
  2005年   108篇
  2004年   100篇
  2003年   105篇
  2002年   86篇
  2001年   20篇
  2000年   30篇
  1999年   39篇
  1998年   21篇
  1997年   12篇
  1996年   9篇
  1995年   6篇
  1994年   7篇
  1993年   10篇
  1992年   15篇
  1991年   8篇
  1990年   8篇
  1989年   12篇
  1988年   7篇
  1987年   13篇
  1986年   7篇
  1985年   9篇
  1984年   4篇
  1983年   9篇
  1982年   8篇
  1981年   6篇
  1978年   5篇
  1977年   6篇
  1974年   5篇
  1973年   4篇
  1972年   5篇
  1971年   5篇
  1967年   4篇
排序方式: 共有2757条查询结果,搜索用时 0 毫秒
51.
52.
53.

Background

In daily clinical practice, it is essential to properly evaluate the postoperative sliding distance of various femoral head fixation devices (HFD) for trochanteric fractures. Although it is necessary to develop an accurate and reproducible method that is unaffected by inconsistent postoperative limb position on radiography, few studies have examined which method is optimal. Therefore, the purpose of this study is to prospectively compare the accuracy and reproducibility of our four original methods in the measurement of sliding distance of the HFD.

Methods

Radiographs of plastic simulated bone implanted with Japanese proximal femoral nail antirotation were taken in five limb postures: neutral, flexion, minute internal rotation, greater external rotation, and flexion with external rotation. Orthopedic surgeons performed five measurements of the sliding distance of the HFD in each of the flowing four methods: nail axis reference (NAR), modified NAR, inner edge reference, and nail tip reference. We also assessed two clinical cases by using these methods and evaluated the intraclass correlation coefficients.

Results

The measured values were consistent in the NAR method regardless of limb posture, with an even smaller error when using the modified NAR method. The standard deviation (SD) was high in the nail tip reference method and extremely low in the modified NAR method. In the two clinical cases, the SD was the lowest in the modified NAR method, similar to the results using plastic simulated bone. The intraclass correlation coefficients showed the highest value in the modified NAR method.

Conclusions

We conclude that the modified NAR method should be the most recommended based on its accuracy, reproducibility, and usefulness.  相似文献   
54.
55.
56.
57.
A 60-year-old female underwent screening colonoscopy. Narrow-band imaging (NBI) without magnification showed a 20-mm, well-demarcated brownish area located close to the dentate line of the anal canal. Conventional white-light imaging revealed an ill-defined, flat lesion with scattered reddish spots at the same site. Magnifying endoscopy with NBI (M-NBI) revealed abnormal microvessels with dilatation, tortuosity, caliber change and various shapes that were similar to the intrapapillary capillary loop patterns seen in esophageal squamous cell carcinoma in situ. Endoscopic submucosal dissection (ESD) was performed, and on histological examination, the resected specimen showed squamous cell carcinoma (SCC) in situ and clear surgical margins. Thus, NBI is an efficient method for detecting superficial SCC in the anal canal and M-NBI may be useful for determining the extent of the lesion. During screening colonoscopy, the anal region should be carefully observed using NBI, as early detection offers a greater opportunity for ESD which is a less invasive procedure.  相似文献   
58.
The Otton frog (Babina subaspera) and Holst’s frog (Babina holsti) are both endangered sister species belonging to family Ranidae. For extensive genetic and ecological research of these species, we isolated and characterized 8 new microsatellite loci of the Otton frog and validated cross-amplification in Holst’s frog along with 8 previously reported loci. The total number of alleles and the expected heterozygosity of newly isolated loci in the Otton frog population ranged from 5 to 12 and from 0.620 to 0.905, respectively. We also confirmed cross-amplification in 4 of the new loci and in all previously reported loci in Holst’s frog with the same level of polymorphism as the Otton frog. Our findings suggest that these novel loci will be applicable for conservation genetic studies across varying scales.  相似文献   
59.
Wiskott–Aldrich syndrome (WAS) is a condition with variable expression, which causes persistent thrombocytopenia and, in its complete form, also causes small platelets and humoral immunodeficiency. A 14-year-old boy, diagnosed with WAS but never treated, presented with symptoms of heart and renal failure. His right buccal region was swollen and his right first molar showed a cyst-like image on dental X-ray films. The boy's symptoms were attributed to an infected cyst, greatly aggravated by WAS-related immunodeficiency. The boy was sedated and the affected tooth and cyst were enucleated. Invasive treatment was safely achieved by paying close attention to whole-body management.  相似文献   
60.
To evaluate the efficacy of company-initiated training of urologists on shock wave lithotripsy (SWL) treatment results, we retrospectively assessed 602 patients who underwent SWL in Nagoya City University Hospital between January 2004 and June 2011 using Lithotripter S (Dornier MedTech, Japan). Training—provided by a training specialist of the company in June 2010—focused on the targeting of renal and proximal ureter stones with a combination of radiography and ultrasonography (US). The stretcher wedges were positioned in the semi-prone position or the semi-supine position for middle and distal ureter stones, respectively. Success rates between 519 pre-training treatments and 83 post-training treatments were compared. Patient age and stone location, burden, number, and composition did not significantly differ between pre- and post-training. Training improved the overall success rate from 66.3 to 87.2 % (P < 0.0001). The mean number of SWL treatments decreased from 1.8 ± 1.8 to 1.4 ± 1.3 (P = 0.01). The first SWL treatment success rate increased from 67.1 to 83.7 % (P = 0.002), and the need for multiple treatments decreased. The frequency of detection of renal and proximal ureter stones by both radiography and US increased from 10.5 % before training to 58.2 % after training (P < 0.0001). Significant factors for successful SWL were determined to be training and prone position for distal ureter stones by multivariate analysis and ultrasonic detection for renal and proximal ureter stones by univariate analysis. Skills in targeting stones using ultrasonography and selecting the proper therapeutic position are essential for improving the success rate of stone removal.  相似文献   
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