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   589529篇
  免费   86216篇
  国内免费   34013篇
耳鼻咽喉   6113篇
儿科学   9976篇
妇产科学   9237篇
基础医学   76422篇
口腔科学   13836篇
临床医学   81579篇
内科学   102108篇
皮肤病学   12388篇
神经病学   40709篇
特种医学   20982篇
外国民族医学   279篇
外科学   66582篇
综合类   80340篇
现状与发展   106篇
一般理论   87篇
预防医学   36914篇
眼科学   16207篇
药学   57785篇
  449篇
中国医学   28118篇
肿瘤学   49541篇
  2024年   1512篇
  2023年   7435篇
  2022年   19153篇
  2021年   25585篇
  2020年   22472篇
  2019年   25718篇
  2018年   26344篇
  2017年   25588篇
  2016年   25367篇
  2015年   32499篇
  2014年   38136篇
  2013年   35913篇
  2012年   40293篇
  2011年   44769篇
  2010年   33682篇
  2009年   24920篇
  2008年   29513篇
  2007年   28750篇
  2006年   28602篇
  2005年   28059篇
  2004年   19060篇
  2003年   17625篇
  2002年   15549篇
  2001年   14115篇
  2000年   14603篇
  1999年   15019篇
  1998年   8776篇
  1997年   8774篇
  1996年   6847篇
  1995年   6239篇
  1994年   5242篇
  1993年   3450篇
  1992年   4924篇
  1991年   4219篇
  1990年   3636篇
  1989年   3180篇
  1988年   2706篇
  1987年   2437篇
  1986年   2001篇
  1985年   1614篇
  1984年   984篇
  1983年   741篇
  1982年   449篇
  1981年   426篇
  1980年   373篇
  1979年   462篇
  1978年   225篇
  1977年   207篇
  1974年   223篇
  1973年   180篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
The objective of this study was to investigate short segment decompression of degenerative lumbar scoliosis (DLS) and the efficiency of fusion treatment.After DLS surgery, the patients were retrospectively reviewed using the VAS (visual analog scale) and ODI (Oswestry Disability Index) to assess clinical outcomes. All patients underwent posterior lumbar decompressive laminectomy, pedicle screw internal fixation, and posterolateral bone graft fusion surgery. Radiographic measurements included the scoliotic Cobb angle, the fused Cobb angle, the anterior intervertebral angle (AIA), the sagittal intervertebral angle (SIA), and lumbar lordosis angle. The relationships between these parameters were examined by bivariate Pearson analysis and linear regression analysis.Preoperatively, the Cobb angle at the scoliotic segment was 15.4°, which decreased to 10.2° immediately following surgery (P < 0.05). The AIA significantly increased by the last follow-up (4.4 ± 3.4) compared with pre- and postoperative values (2.5 ± 2.8 and 2.2 ± 2.4, respectively; P < 0.05). However, the scoliotic Cobb angle and the AIA did not correlate with the VAS or ODI scores. At the final follow-up, no patients had pseudoarthrosis or internal instrumentation-related complications.Short fusion surgical treatment results in limited DLS correction, with correction loss over time. The AIA between the upper adjacent segment and proximal fused vertebra continues to increase postoperatively, which does not exacerbate clinical symptoms, as reflected by the low reoperation rates for repairing degeneration at adjacent levels.  相似文献   
94.
95.
96.
97.
98.
Objective: Association of matrix metalloproteinases (MMPs) gene polymorphisms with rheumatoid arthritis is controversial. We conduct a meta-analysis to clarify this dispute.

Methods: We systematically searched the electronic PUBMED, EMBASE and CNKI databases for research articles about MMPs (MMP-1, MMP-2, MMP-3, MMP-9) gene polymorphisms and rheumatoid arthritis (RA) up to January 2015. According to the heterogeneity, fixed-effects or random-effects models were used to calculate crude odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results: A total of 11 articles involving 2143 cases and 2049 controls were included in this meta-analysis. Overall, no significant associations were observed between MMP-1-1607 1G/2G polymorphism and RA. Stratification by ethnicity, no significant associations were observed in Caucasian populations. Similarly, no significant associations were observed between MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms and RA in overall and Caucasian populations, respectively. However, a weak association was found between MMP-2-1306 C/T polymorphism and RA (C vs. T, OR?=?0.813, 95%CI?=?0.694–0.953, p?=?0.010) in overall populations.

Conclusions: The present meta-analysis suggests that MMP-1-1607 1G/2G, MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms are not associated with the susceptibility of RA, but MMP-2 -1306 C/T is weakly associated with susceptibility to RA. Further studies with more sample size are needed for definitive conclusions.  相似文献   
99.
BACKGROUNDGuillain-Barré syndrome (GBS) is a rare disorder that typically presents with ascending weakness, pain, paraesthesias, and numbness, which mimic the findings in lumbar spinal stenosis. Here, we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARYA 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness. Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis. However, his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness. An electromyogram was performed. Based on his symptoms, physical examination, and electromyogram, he was diagnosed with GBS. After 5 d of intravenous immunoglobulin (0.4 g/kg/d for 5 d) therapy, he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias. He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSIONGBS should be considered in the differential diagnosis of spinal disorder, even though magnetic resonance imaging shows severe lumbar spinal stenosis. This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms.  相似文献   
100.
A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid‐filled sac.  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