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   1727篇
  免费   115篇
  国内免费   111篇
儿科学   40篇
妇产科学   3篇
基础医学   165篇
口腔科学   11篇
临床医学   193篇
内科学   47篇
皮肤病学   1篇
神经病学   60篇
特种医学   44篇
外科学   1070篇
综合类   223篇
预防医学   29篇
眼科学   10篇
药学   21篇
中国医学   21篇
肿瘤学   15篇
  2024年   19篇
  2023年   48篇
  2022年   65篇
  2021年   89篇
  2020年   85篇
  2019年   56篇
  2018年   61篇
  2017年   71篇
  2016年   62篇
  2015年   59篇
  2014年   134篇
  2013年   202篇
  2012年   112篇
  2011年   124篇
  2010年   78篇
  2009年   69篇
  2008年   93篇
  2007年   84篇
  2006年   61篇
  2005年   54篇
  2004年   50篇
  2003年   33篇
  2002年   25篇
  2001年   16篇
  2000年   10篇
  1999年   20篇
  1998年   15篇
  1997年   15篇
  1996年   16篇
  1995年   14篇
  1994年   5篇
  1993年   17篇
  1992年   9篇
  1991年   6篇
  1990年   3篇
  1989年   5篇
  1988年   2篇
  1987年   8篇
  1986年   1篇
  1985年   3篇
  1984年   2篇
  1983年   6篇
  1982年   8篇
  1981年   8篇
  1980年   7篇
  1979年   6篇
  1978年   6篇
  1977年   2篇
  1976年   4篇
  1975年   5篇
排序方式: 共有1953条查询结果,搜索用时 9 毫秒
1.
目的:检测神经纤维瘤蛋白在先天性脊柱侧凸患者成骨细胞和软骨细胞中的表达。方法:6例先天性脊柱侧凸患者,在后路手术时取髂骨及髂骨生长板,分离、培养成骨细胞和软骨细胞,分别行碱性磷酸酶染色和甲苯胺蓝染色。逆转录-多聚酶链反应(RT—PCR)检测神经纤维瘤蛋白mRNA.间接免疫荧光和Westemblot检测神经纤维瘤蛋白在成骨细胞和软骨细胞中的表达。结果:先天性脊柱侧凸患者成骨细胞和软骨细胞中存在Ⅱ型神经纤维瘤蛋白表达,该蛋白主要分布在细胞浆,所表达蛋白为三磷酸鸟苷酶活化蛋白(GAP)活性较弱的Ⅱ型异构体。结论:先天性脊柱侧凸患者成骨细胞和软骨细胞中存在神经纤维瘤蛋白表达,但该蛋白是否通过对成骨细胞和软骨细胞的影响导致骨骼系统异常还有待于进一步研究。  相似文献   
2.
脊柱侧凸翻修手术   总被引:1,自引:1,他引:0       下载免费PDF全文
目的探讨脊柱侧凸手术失败原因及翻修手术的处理方法。方法回顾性分析我院自1997年以来收治的脊柱侧凸矫形术后需要进行翻修手术患者33例。男10例,女23例。翻修时距初次手术时间平均为13.4个月(0.5.66个月)。33例患者共行43次翻修手术,其中29例进行1次翻修手术,2例进行3次翻修手术,2例进行4次翻修手术。另有4例患者增加脊柱矫形和融合,同时行脊柱前路松解、支撑植骨手术。结果翻修手术时间平均3.9h(1.5—7.3h),手术中平均出血601ml(50—2000ml),平均输血量643.3mk(0-2000ml)。术后随访平均27个月(3—67个月),未出现畸形加重、内固定失败等并发症。结论脊柱侧凸翻修手术是脊柱畸形矫形术后的一种补救手术。术前完善的手术策略和良好的手术技术是翻修手术的关键。  相似文献   
3.
同种异体骨与自体骨移植治疗青少年脊柱侧凸的比较研究   总被引:3,自引:1,他引:2  
[目的]观察同种异体骨移植与自体骨移植治疗青少年脊柱侧凸的临床效果.[方法]对1996~2006年本科收治的63例青少年脊柱侧凸患者的临床资料,采用回顾性"病例-对照"研究方法进行分析,A组(同种异体骨移植组)32例,10~15岁,平均12.2岁;Cobb's角38°~113°,平均62°;B组(自体髂骨移植组)31例,年龄9~14岁,平均12.4岁;Cobb's角41°~105°,平均54°.所有患者均选择中华长城椎弓根内固定系统经后路矫正,术后定期随访并对临床效果进行评估.[结果]出院后2个月即开始随访,随访时间18~24个月,平均26个月;亦无严重并发症发生;A组的手术时间、失血量较B组患者减少,组间具有统计学意义(P<0.01).[结论]两组患者具有相似的临床效果,在严格掌握适应证,充分术前准备、正确手术操作、及时术后处理的前提下,同种异体骨移植能够有效替代自体髂骨移植治疗青少年脊柱侧凸.  相似文献   
4.
Summary The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8°, r 13°–30°) and from 33 with severe scoliosis (mean Cobb angle 46.2°, r 35°–71°). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation.  相似文献   
5.
The concave and convex rib-vertebral angle (RVA) at levels T2–T12 was measured on AP radiographs of 19 patients with right convex idiopathic thoracic scoliosis and 10 patients with major thoracic right convex neuromuscular scoliosis. The difference between the angles on the concave and the convex sides, the RVAD, was calculated. The RVAs were also measured on radiographs from three animal groups in which spinal curves had been induced experimentally in a variety of ways. Group 1 comprised 16 rabbits that had been subjected to selective electrostimulation of the latissimus dorsi, the erector spinae and the intercostal muscles. Group 2 comprised four dead rabbits whose spines had been subjected to manual bending. Group 3 comprised eight rabbits that had undergone mechanical elongation of one rib. In both the idiopathic and the neuromuscular group, the convex RVA was smaller than the concave RVA between levels T2 and T8, with a maximal difference between T4 to T5. From T9 to T12 the concave RVA was smaller than the convex. The RVA in relation to the scoliotic segment, i.e. the apex level of the curve and the two neighbouring vertebrae above and below this level, showed similar results. With increasing Cobb angle the RVADs increased linearly with the greatest difference at the second vertebra above the apex. In the three experimental groups the pattern of the RVADs between T6 to T12 was basically similar to the findings of the clinical study. From the results of these clinical and experimental studies, it is concluded that the typical pattern of the RVAs on the concave and convex sides seems to be independent of the underlying cause of the spinal curvature. It is likely that the RVADs result from a passive mechanical adaptation of the ribs to the lateral curvature of the spine.  相似文献   
6.
Venous air embolism during surgery is a rare but important complication and can be rapidly fatal. We present two cases of fatal air embolism in the prone position occurring in small children undergoing surgery for progressive scoliosis.
Venous air embolism is a rare complication in the prone position. This is thought to be because in this position there is virtually no gravitational gradient between the site of surgery and the right atrium.
The possible sites of entry of air and ways that this may be minimized are discussed.  相似文献   
7.
低角度青少年特发性脊柱侧凸女性患者的骨密度分析   总被引:1,自引:0,他引:1  
目的分析低角度青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)女性患者的骨密度(BMD)和骨矿含量(BMC),探讨其与年龄、生长发育、人体测量学和侧凸角度等的相关性。方法研究对象为218例Cobb角15~40°的女性AIS患者。运用双能X线骨密度吸收仪测定非优势侧股骨颈和腰椎的BMC/BMD。探讨这两个部位的BMC/BMD与患者的年龄、生长发育、人体测量学和侧凸角度等的相关性。结果所有患者的年龄平均为(13.4±1.4)岁,Cobb角平均为(28.3±6.2)°。股骨颈BMD平均为(0.827±0.103)g/cm2,腰椎BMD平均为(0.887±0.124)g/cm2,显著低于同龄健康女性儿童;股骨颈BMC平均为(3.49±0.56)g,腰椎BMC平均为(29.78±7.37)g。患者的BMC/BMD与Cobb角无显著相关,而与体重、身高、Risser征、月经状况、BMI和年龄显著相关。逐步回归分析显示,体重和年龄是影响患者BMD的主要因素。结论低角度女性AIS患者存在全身性的骨量减低,且与Cobb角无显著相关,而与生长发育和人体测量学相关指标显著相关。这提示AIS患者的骨量减低与生长发育和低体重有关。  相似文献   
8.
退变性腰椎侧凸的外科治疗   总被引:4,自引:0,他引:4  
目的探讨退变性腰椎侧凸的特点、诊断与治疗。方法2001年7月至2004年1月手术治疗退变性脊柱侧凸患者15例,行后路彻底椎板减压、椎弓根钉棒矫形固定,椎间融合器融合12例,后外侧植骨融合3例,回顾性分析其临床特点、手术方法与效果。结果术后侧凸平均矫正率为42.8%,腰腿痛均消失,下肢麻木等症状减轻,随访6~36个月,植骨融合良好,无融合器移位,矫正度数与椎间隙高度无丢失。结论成人退变性腰椎侧凸发病年龄大,多合并腰椎管狭窄、失稳等,腰腿痛原因复杂,治疗的主要目的是彻底减压,通过矫形使脊柱重新获得稳定,椎弓根钉棒固定及椎间融合是有效的治疗方法。  相似文献   
9.
Fifteen skeletally immature patients with double major adolescent idiopathic scoliosis with large lumbar curves and notable L4 and L5 coronal plane obliquity were retrospectively studied. Seven patients who underwent anterior release and fusion of the lumbar curve with segmental anterior instrumentation and subsequent posterior instrumentation ending at L3 were compared with eight patients treated with anterior release and fusion without anterior instrumentation followed by posterior instrumentation to L3 or L4. At 4.5 years follow-up (range 2.5-7 years), curve correction, coronal balance and fusion rate were not statistically different between the two groups; however, the group with anterior instrumentation had improved coronal plane, near normalangulation in the distal unfused segment compared with the group without anterior instrumentation. In cases involving severe lumbar curvatures in the context of double major scoliosis, when as a first stage anterior release is chosen, the addition of instrumentation appears to restore normal coronal alignment of the distal unfused lumbar segment, and may in certain cases save a level compared with traditional fusions to L4.  相似文献   
10.
Our objectives were to describe fetal cases of vertebral defects (VD), assess the diagnostic yield of fetal chromosomal analysis for VD and determine which investigations should be performed when evaluating fetal VD. We performed a retrospective chart review for fetuses with VD seen between 2006 and 2015. Cases were identified from CHU Sainte‐Justine's prenatal clinic visits, postmortem fetal skeletal surveys, and medical records. Cases with neural tube defects were excluded. Sixty‐six fetuses with VD were identified at a mean gestational age of 20 weeks. Forty‐seven (71.2%) had associated antenatal anomalies, most commonly genitourinary, skeletal/limb, and cardiac anomalies. Thirteen mothers (19.7%) had pregestational diabetes (95% CI [10.1%–29.3%]). Fifty‐three cases had chromosomal analysis. Three had abnormal results (5.6%): trisomy 13, trisomy 22, and 9q33.1q34.11 deletion. Thirty‐four (51.5%) pregnancies were terminated, one led to intrauterine fetal demise and 31 (46.9%) continued to term. Of 27 children who survived the neonatal period, 21 had congenital scoliosis and 3 had spondylocostal dysostosis. Seven had developmental delay. In conclusion, prenatal evaluation of fetuses with VD should include detailed morphological assessment (including fetal echocardiogram), maternal diabetes screening, and chromosomal microarray if non‐isolated. Our findings provide guidance about management and counseling after a diagnosis of fetal VD.  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