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   29194篇
  免费   1763篇
  国内免费   1103篇
耳鼻咽喉   1020篇
儿科学   616篇
妇产科学   96篇
基础医学   1525篇
口腔科学   3527篇
临床医学   2800篇
内科学   4635篇
皮肤病学   35篇
神经病学   1500篇
特种医学   1921篇
外国民族医学   1篇
外科学   7001篇
综合类   4089篇
现状与发展   2篇
预防医学   535篇
眼科学   232篇
药学   1184篇
  14篇
中国医学   993篇
肿瘤学   334篇
  2024年   95篇
  2023年   558篇
  2022年   839篇
  2021年   1183篇
  2020年   1174篇
  2019年   1051篇
  2018年   1072篇
  2017年   905篇
  2016年   1000篇
  2015年   1080篇
  2014年   2153篇
  2013年   1935篇
  2012年   1746篇
  2011年   1859篇
  2010年   1589篇
  2009年   1450篇
  2008年   1328篇
  2007年   1380篇
  2006年   1297篇
  2005年   1079篇
  2004年   919篇
  2003年   829篇
  2002年   682篇
  2001年   561篇
  2000年   483篇
  1999年   478篇
  1998年   398篇
  1997年   351篇
  1996年   292篇
  1995年   294篇
  1994年   263篇
  1993年   249篇
  1992年   212篇
  1991年   156篇
  1990年   128篇
  1989年   134篇
  1988年   114篇
  1987年   100篇
  1986年   94篇
  1985年   109篇
  1984年   83篇
  1983年   37篇
  1982年   76篇
  1981年   58篇
  1980年   54篇
  1979年   38篇
  1978年   29篇
  1977年   18篇
  1976年   18篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
Precise and limited decompression for lumbar spinal stenosis   总被引:3,自引:0,他引:3  
Summary Fifty-eight consecutive patients with lumbosacral nerve root entrapment due to spinal stenosis were treated with modified microsurgical decompression. Only the clinically relevant sides and levels were decompressed while the spinous processes, the interspinous ligaments, the medial portion of ligamentum flavum and the functionally important parts of the facet joints were preserved. The reviewers rated recovery as good or excellent in 71% of patients while patient self-assessment indicated 76% good or excellent outcome. These data suggest that microsurgical decompression of spondyloarthritic changes can effectively relieve the signs and symptoms of nerve root compression and that with careful evaluation of all available data the number of nerve roots requiring decomperession is often fewer than what is suggested by diagnositic images alone.  相似文献   
42.
During a period of twenty years [1969-1988] the author has observed 614 cases of congenital malformations and noninflammatory diseases of the larynx in infants and young children, Budapest. He summarizes the most characteristic symptoms of laryngeal pathology in infants, and discusses the diagnostic possibilities. Among the latter, spectrographic analyses complemented by auditory evaluation of pathological cry and different breathing noises play an important role. Based on his investigation author differentiates 20 kinds of pathological crying sounds and 4 basic forms of stridor. He describes the acoustic attributes of different pathological sound phenomena and summarizes characteristic voice changes.  相似文献   
43.
44.
用2‰游标卡尺对114具L1~L5段椎骨标本进行测量,包括椎孔上缘矢径及下缘矢径的距离和相互关系。结果:腰椎孔下缘矢径明显大于上缘矢径(P<0.01),腰椎孔下缘矢径明显大于腰椎孔中矢径。为腰椎管狭窄的临床诊断提供解剖学基础。  相似文献   
45.
通用型脊柱内固定系统椎弓根螺钉翻修作用的生物力学研究   总被引:25,自引:0,他引:25  
目的测试自行设计的通用型脊柱内固定系统(generalspinesystem,GSS)椎弓根螺钉以及SOCON、TSRH和Diapason螺钉置入椎体的拔出力及旋入力矩,评价GSS螺钉的翻修作用。方法将36个正常成人腰椎椎体标本随机分为三组,每组12个椎体(24侧椎弓根)。各组标本每个椎体的每侧椎弓根均先拧入CCD螺钉(直径6.0mm,长45mm),行螺钉拔出试验,测试并记录螺钉的最大旋入力矩和最大轴向拔出力。然后各组标本每个椎体均随机选择一侧椎弓根经原钉道拧入GSS螺钉(直径6.5mm,长45mm);第一组另一侧拧入SOCON螺钉(直径7.0mm,长45mm),第二组另一侧拧入TSRH螺钉(直径7.0mm,长45mm),第三组另一侧拧入Diapason螺钉(直径6.7mm,长45mm)。分别测试螺钉最大旋入力矩及最大轴向拔出力。结果第一组GSS螺钉最大轴向拔出力为CCD螺钉的114%,SOCON螺钉为CCD螺钉的108%;GSS螺钉最大轴向拔出力大于SOCON螺钉,差异无显著性(P>0.05);GSS螺钉最大旋入力矩小于SOCON螺钉,差异无显著性(P>0.05)。第二组GSS螺钉最大轴向拔出力为CCD螺钉的127%,TSRH螺钉为CCD螺钉的64%;GSS螺钉最大轴向拔出力大于TSRH螺钉,差异有显著性(P<0.01);GSS螺钉最大旋入力矩大于TSRH螺钉,差异有显著性(P<0.01)。第三组GSS螺钉最大轴向拔出力为CCD螺钉的122%,Diapason螺钉为CCD螺钉的8  相似文献   
46.
Summary The prevalence of smoking, hypertension and diabetes mellitus was assessed in 221 patients suffering from internal carotid stenosis and compared with the prevalences in two sex- and age-matched control groups composed of subjects having normal Doppler findings and from non-neurological outpatients. Of the subjects with carotid stenosis 27.6% were hypertensive smokers in comparison with 9.5% and 17.2% in the two control groups. The difference of the stenosis cohort from the two control groups was significant (P<0.01 and P=0.016 respectively). There was no statistically significant differences between the occurrence of diabetes and hypertension in non-smokers and patients who smoked. In 394 investigated patients suffering from carotid stenosis or occlusion an obstruction index, based on the Doppler shift frequency, was calculated. This index was lowest in the normotentive non-smokers. It was only insignificantly higher in the hypertensive non-smokers but significantly so in the normotensive smokers. The index was highest in the hypertensive non-smokers. It was concluded that cigarette smoking, especially if associated with hypertension, is a determinant risk factor for carotid stenosis and occlusion.  相似文献   
47.
经皮穿刺髓核成形术治疗腰椎间盘突出症初步临床报道   总被引:36,自引:2,他引:34  
目的 寻求一种简单、安全、有效、微创的椎间盘突出症治疗方法。方法 对 1 6例腰椎间盘突出症采用经皮穿刺髓核成形术 (Nucleoplasty)治疗 ,并对其疗效进行观察分析。 结果 全部患者经二周至一个月短期随访 ,症状均有不同程度改善 ,疗效优良率为 93 8% ,有效率为 1 0 0 %。未发现明显并发症。结论 髓核成形术是一种先进、安全、有效的椎间盘突出微创手术 ,具有操作简单、安全、微创、疗效佳、恢复快、无需住院等优点。  相似文献   
48.
BACKGROUND CONTEXT: There is limited information describing the correlation between the initial quantitative measurements on magnetic resonance imaging (MRI) scans of disc herniation area, canal cross-section areas, percent canal compromise, and disc herniation location to the need for surgery. PURPOSE: Our aim is to determine if the size of disc herniation area, canal cross-section area, percent canal compromise, and disc herniation location taken from MRI images of patients with symptomatic single-level lumbar herniated intervertebral discs upon initial presentation to a spine surgeon, were predictive of the need for surgical treatment. STUDY DESIGN/SETTING: This is a retrospective case matched study of patient MRI images in the senior author's private practice. PATIENT SAMPLE: From a pool of 332 patients with sciatica caused by lumbar intervertebral disc herniations at our institution, 65 patients had surgery, of which MRI images were available and analyzed on 44 patients. Forty-four additional patients were randomly selected from the remaining 267 original group as nonoperative controls. METHODS: The axial MRI image showing the largest canal compromise by the herniated disc was selected for measurements. Using T1- and T2-weighted images, the areas of interest were digitally scanned at high resolution. The canal area and disc herniation area measurement were calculated from the total number of pixels per cross-sectional area, multiplied by a scan correction factor, mm(2) /pixel. Disc herniation locations were classified into either central or paracentral. The percent canal compromise was obtained by disc herniation area divided by canal cross-section area and multiplied by 100. RESULTS: The surgical group's overall mean herniated disc area was 219.6 square millimeter (mm(2)), 179.8 at L4-5, and 267.4 at L5-S1. The nonoperative group's overall mean herniated disc area was 178.4 mm(2), 135.1 at L2-3, 160.3 at L4-5, and 207.4 at L5-S1. The surgical group's overall mean canal cross-sectional area was 471.8 mm(2), 418.6 at L4-5, and 535.6 at L5-S1. The nonoperative group's overall mean canal cross-sectional area was 541.3 mm(2), 518.1 at L2-3, 446.8 at L4-5, and 669.9 at L5-S1. The overall percent canal compromise ratio in the surgery group was 46.7%, 44.1% at L4-5, and 49.8% at L5-S1. The overall percent canal compromise in the nonoperative group was 34.2%, 34.1% at L2-3, 36.1% at L4-5, and 31.8% at L5-S1. The percent canal compromise in central herniations at L4-5 level was 53.0% in the surgical group, and 32.8% in the nonoperative group; at the L5-S1 level surgical group percent canal compromise was 64.1% and in the nonoperative group canal compromise was 27%. L4-L5 level paracentral herniations canal compromise was 36.7% in the surgical group compared with 42.5% canal compromise in the nonoperative group. At the L5-S1 level the canal compromise was 45% in the surgical group and 34.8% in the nonoperative group. CONCLUSIONS: Our findings show a trend for patients treated with surgery to have larger disc herniation areas and smaller canal cross-section areas, corresponding to larger percent canal compromise than the nonoperative group. Centrally located herniations followed this trend closely at all levels studied. However, the paracentral herniation at the L4-5 level does not follow this trend, possibly because paracentral disc herniation clinical course is determined more by herniation location rather than the overall herniation size.  相似文献   
49.
50.
168例食管烧伤后瘢痕狭窄的预防和治疗   总被引:2,自引:0,他引:2  
目的 总结食管烧伤后瘢痕狭窄预防和治疗的经马命。方法 168例中158例进行了172次外科治疗,11例进行了2次以上手术。早期人院Ⅱ度期以上34例采用改良食管腔内置管预防食管烧伤后瘢痕,末切除瘢痕狭窄结肠重建77例,切除狭窄食管胃重建27例,颈阔肌皮瓣修复颈部食管狭窄22例,其他类型手术12例。结果 29例拔出支撑管后治愈(85%);5例再狭窄,其中1例扩张治愈。77例结肠重建术后5例死亡,颈部吻合口瘘14例,吻合口狭窄4例,腹部切口裂开2例。27例胃重建中,吻合口狭窄2例。脓胸1。颈阔肌皮瓣修复颈段狭窄22例中,3例发生颈部瘘。其他手术12例中,1例术后死于肠梗阻。所有生存出院患者均能进普食。 结论 管腔内置管能有效预防食管烧伤后瘢痕形成,根据瘢痕狭窄部位确定食管重建时是否切除狭窄食管。颈阔肌皮瓣是修复颈段食管狭窄或吻合口狭窄的优良方法。  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