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   1666篇
  免费   145篇
  国内免费   60篇
耳鼻咽喉   38篇
儿科学   26篇
妇产科学   8篇
基础医学   223篇
口腔科学   44篇
临床医学   83篇
内科学   62篇
皮肤病学   12篇
神经病学   26篇
特种医学   60篇
外科学   418篇
综合类   166篇
预防医学   9篇
眼科学   636篇
药学   29篇
中国医学   9篇
肿瘤学   22篇
  2024年   10篇
  2023年   29篇
  2022年   81篇
  2021年   69篇
  2020年   67篇
  2019年   57篇
  2018年   75篇
  2017年   66篇
  2016年   70篇
  2015年   66篇
  2014年   91篇
  2013年   128篇
  2012年   76篇
  2011年   105篇
  2010年   92篇
  2009年   85篇
  2008年   64篇
  2007年   70篇
  2006年   71篇
  2005年   74篇
  2004年   51篇
  2003年   33篇
  2002年   34篇
  2001年   31篇
  2000年   29篇
  1999年   21篇
  1998年   20篇
  1997年   25篇
  1996年   11篇
  1995年   15篇
  1994年   18篇
  1993年   13篇
  1992年   12篇
  1991年   8篇
  1990年   17篇
  1989年   9篇
  1988年   9篇
  1987年   6篇
  1986年   5篇
  1985年   12篇
  1984年   10篇
  1983年   6篇
  1982年   7篇
  1981年   8篇
  1980年   6篇
  1979年   2篇
  1978年   3篇
  1976年   1篇
  1975年   3篇
排序方式: 共有1871条查询结果,搜索用时 15 毫秒
81.
目的:探讨用MRI检测骨化中心出现的时间、位置、形态等,和组织学进行对比性研究。方法:用FLASH2D梯度回波加脂肪抑制序列检测了胎龄6-8个月女性股骨远近端。同时与相应组织学H-E染色标本比较。结果:MRI检测结果:胎龄7个月 的81%股骨远端出现骨化中心征象,骨化中心始于偏心位。8个月 的股骨远端均出现骨化中心征象。胎龄7个月 、8个月 的股骨近端和6个月 股骨远近端均未出现骨化中心征象。H-E切片观测结果:证实了MRI检测阳性区有早期骨化中心征象。结论:MRI能检测出早期表达区,早于X线中所见,骨化中心见于骨组织尚未完全形成之前。  相似文献   
82.
BACKGROUNDThe short-term therapeutic efficacy of kyphoplasty on Kummell’s disease is obvious. However, postoperative refracture and adjacent vertebral fracture occur occasionally and are difficult to treat. Parkinson''s disease (PD) is a pathological disorder associated with heterotopic ossification. In a patient with PD, an intervertebral bridge was formed in a short period of time after postoperative refracture and adjacent vertebral fracture, providing new stability.CASE SUMMARYA 78-year-old woman had been suffering from PD for more than 10 years. Three months before operation, she developed lower back pain and discomfort. The visual analog scale (VAS) score was 9 points. Preoperative magnetic resonance imaging indicated collapse of the L2 vertebra. Kyphoplasty was performed and significantly decreased the severity of intractable pain. The patient’s VAS score for pain improved from 9 to 2. Fifty days postoperatively, the patient suddenly developed severe back pain, and the VAS score was 9 points. X-ray showed L2 vertebral body collapse, slight forward bone cement displacement, L1 vertebral compression fracture, and severe L1 collapse. The patient was given calcium acetate capsules 0.6 g po qd and alfacalcidol 0.5ug po qd, and bed rest and brace protection were ordered. After conservative treatment for 2 mo, the patient''s back pain was alleviated, and the VAS score improved from 9 to 2. Computed tomography at the 7-mo follow-up indicated extensive callus formation around the T12-L2 vertebrae and intervertebral bridging ossification, providing new stability.CONCLUSIONKyphoplasty is currently a conventional treatment for Kummell''s disease, with definite short-term effects. However, complications still occur in the long term, and these complications are difficult to address; thus, the treatment needs to be selected carefully. To avoid refracture, an interlaced structure of bone cement with trabeculae should be created to the greatest extent possible during the injection of bone cement. Surgical intervention may not be urgently needed when a patient with PD experiences refracture and adjacent vertebral fracture, as a strong bridge may help stabilize the vertebrae and relieve pain.  相似文献   
83.
The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein‐2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD‐treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
84.
Context: Deep vein thrombosis (DVT), a frequent complication of spinal cord injury, is occasionally caused by neurogenic heterotopic ossification (NHO). In most cases of NHO, the hip joint is affected. Herein, we present a case of paraplegia following radiation-induced myelopathy that presented with left leg swelling due to DVT in the common iliac vein (CIV) caused by venous compression by NHO on the anterior lower lumbar spine.Findings: A 28-year-old man with complete paraplegia due to radiation-induced myelopathy presented with left lower extremity swelling 6 years after the onset of paraplegia. DVT in the left CIV was observed on computed tomography venography. The left CIV was significantly compressed between the NHO at the anterior longitudinal ligament of the lumbar spine and the right common iliac artery, suggestive of May-Thurner syndrome. Slightly distal to that compressed area, the left CIV was significantly compressed by the large NHO at the anterior longitudinal ligament of the lumbar spine.Conclusions: We believe that such compression of the left CIV would have contributed to the development of DVT. This case shows that DVT might be caused by NHO at the anterior aspect of the lumbar vertebral body, and this may help clinicians identify the main cause of DVT in the leg.  相似文献   
85.
目的:探讨人工全髋关节置换术(THA)和翻修术后异位骨化(HO)形成的影响因素、临床特点、创伤机制和预防方法.方法:我院2004年1月~2010年12月行THA及翻修术287例,其中男98例,女189例;年龄56~72岁,平均63岁.其中≤65岁140例,>65岁147例;THA 257例,翻修术30例.所有患者术后均口服阿斯匹林50 mg/d×30 d.两位骨科医师根据患者术前和术后双髋关节正、侧位X线摄片,按Brooker分级标准评定HO产生情况.按Harris评分标准评定髋关节功能.结果:本组287例均随访1 a以上,共有45例发生HO(15.68%),其中Brooker I型29例(64.44%),BrookerⅡ型14例(31.11%),BrookerⅢ型2例(4.44%),未发现BrookerⅣ型.HO发生率在男性为23.47%、女性11.64%,≤65岁10.71%、>65岁20.41%,初次THA后10.89%、翻修术后56.67%,不同性别、年龄、术式间比较,差异均有统计学意义(P<0.05).结论:在THA及翻修术后应常规预防HO;对HO形成的高危因素如翻修手术,围手术期应尽早采取干预措施.  相似文献   
86.
尸体胸椎黄韧带骨化的病理观察   总被引:6,自引:0,他引:6  
研究兴柱黄韧带骨化的病理特征。方法:随机选择21具尸体胸椎标本,矢状剖开18具,冠状剖开3具,观察每一节段黄韧带病理学特征,对骨化标本进行病理学研究。结果;21具标本中,9具59节段骨化,其中增生骨化4具,23节段占39%,单纯骨化7具,累积36节段,病理表现呈3层结构。  相似文献   
87.
88.
目的:通过诱发大鼠下颌骨垂直向功能性移位,阐明这一方向上的位移在髁突改建中的作用.方法:5周龄雌性SD大鼠40只,随机分为实验组和对照组,实验组大鼠佩戴上颌后牙(牙合)垫,使下颌骨发生垂直向功能性移位.实验组大鼠进一步分为4组,每组5只,分别在佩戴袷垫后第3、6、9、12天处死.采用组织形态学测量及AB-PAS染色,定量分析髁突的形态及软骨的组织学变化.采用SPSS11.0软件包对对照组和实验组的各项指标进行统计学分析.结果:下颌垂直向功能性移位后12d,髁突高度较对照组显著增加,前斜面更倾斜;髁突后上区前成软骨细胞及成软骨细胞层厚度在实验第3~6天无明显差异,第9天开始出现显著变化,实验组较对照组显著增厚,这种变化持续到实验第12天;肥大软骨细胞层厚度在实验第3、9、12天,实验组与对照组无显著差异,在实验第6天较对照组显著减少,间充质细胞层变化不大.结论:下颌垂直向功能性移位可致髁突高度增加、前斜面更倾斜,髁突软骨厚度的增加是髁突高度增加的组织学基础,垂直向移位也是构成功能性矫治器促进下颌骨发育的重要方面.  相似文献   
89.
Neurogenic heterotopic ossification is a process of abnormal bone formation of multi-factorial aetiology. It occurs at varying sites to produce deformity and restriction of joint movement, and has a major impact on physical ability. There is extensive literature on the medical management of heterotopic ossification, but the role of physiotherapy is poorly described.This article aims to illustrate the importance of proactive physiotherapy in the team management and treatment of this condition. The authors show that physiotherapy is not contra-indicated in the presence of neurogenic heterotopic ossification and illustrate how interventions for improving range of movement can be used. The authors suggest that integrated team management was essential to the successful outcomes in these complex cases.  相似文献   
90.
Extra-articular heterotopic bone formation was recognized as a postoperative complication of arthroscopic anterior cruciate ligament reconstructions in four knees around the femoral drill hole. Although laxity of the reconstructed anterior cruciate ligament was not observed in these patients, local pain, swelling, and deformity at the site of heterotopic ossification required surgical intervention. The ectopic bone can be successfully excised with restoration of function. The incidence rate of this complication is less than 1%.  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