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   4301篇
  免费   239篇
  国内免费   79篇
耳鼻咽喉   10篇
儿科学   21篇
妇产科学   5篇
基础医学   325篇
口腔科学   48篇
临床医学   388篇
内科学   158篇
皮肤病学   6篇
神经病学   505篇
特种医学   203篇
外科学   1935篇
综合类   489篇
预防医学   205篇
眼科学   97篇
药学   144篇
  3篇
中国医学   48篇
肿瘤学   29篇
  2024年   7篇
  2023年   93篇
  2022年   120篇
  2021年   187篇
  2020年   138篇
  2019年   141篇
  2018年   161篇
  2017年   175篇
  2016年   137篇
  2015年   160篇
  2014年   317篇
  2013年   305篇
  2012年   244篇
  2011年   310篇
  2010年   243篇
  2009年   202篇
  2008年   213篇
  2007年   218篇
  2006年   178篇
  2005年   197篇
  2004年   131篇
  2003年   107篇
  2002年   80篇
  2001年   72篇
  2000年   55篇
  1999年   44篇
  1998年   55篇
  1997年   49篇
  1996年   38篇
  1995年   42篇
  1994年   38篇
  1993年   29篇
  1992年   23篇
  1991年   24篇
  1990年   10篇
  1989年   12篇
  1988年   7篇
  1987年   11篇
  1986年   9篇
  1985年   7篇
  1984年   6篇
  1983年   4篇
  1982年   5篇
  1981年   4篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1973年   1篇
排序方式: 共有4619条查询结果,搜索用时 15 毫秒
41.
Degenerative spondylolisthesis is characterized by the slippage of one vertebral body over the one below, with association of intervertebral disc degeneration and degenerative arthritis of the facet joints, which cause spinal stenosis. The aim of this study was to evaluate the clinical and radiographic results of 22 patients with symptomatic degenerative spondylolisthesis, operated on by decompressive laminectomy and instrumented posterolateral fusion associated with interbody fusion (PLIF). Mean age at surgery was 64 years (range, 57–72). Clinical results were evaluated on a questionnaire at the last follow-up visit concerning postoperative low back and leg pain, restriction of daily life activities, and resumption of sports activity. Lumbar spine radiographs were used to evaluate the status of fixation devices, the reduction of the spondylolisthesis, the lumbar sagittal balance and the presence of spinal fusion. No intraoperative or postoperative complications were encountered. There were no superficial or deep infections, fixation device loosening, or hardware removal. Mean follow-up time was 4 years (range, 3–6 years). Clinical outcome was excellent or good in 19 patients and fair in 3 patients. Preoperatively, mean forward vertebral slipping on neutral lateral radiographs was 5 mm, while postoperatively it decreased to 3 mm. Preoperatively, mean sagittal motion was 3 mm and angular motion was 8°, while postoperatively these values decreased to 1 mm and 1°, respectively. This study demonstrated that spinal decompression followed by transpedicular instrumentation associated with PLIF technique is a valid surgical option for the treatment of degenerative spondylolisthesis with symptomatic spinal stenosis. Clinical outcome, intended as relief of pain and resumption of activity, was improved significantly and fusion rate was high.  相似文献   
42.
肘管综合征的解剖和病因学探讨   总被引:9,自引:0,他引:9  
[目的]探讨肘管综合征的解剖特点和发病原因。[方法]对65例肘管综合征患者的临床资料和术中所见,以及其中25例患者术前肌电图检查的结果进行综合研究分析。[结果]术中见60例患者存在肘管弓状韧带的肥厚增生,卡压磨损尺神经导致炎性病变;术前肌电图检查发现25例患者的尺神经传导速度均减慢,平均传导速度为27.97m/s;运动反应波幅降低,平均电压为1.95mv;潜伏期延长,平均时间为5.41ms;65例肘管综合征患者,继发于肘部创伤25例,慢性劳损15例,慢性骨关节炎14例,占位病变5例,先天异常有6例。[结论]肘部的创伤及慢性劳损可以导致肘管弓状韧带出现肥厚增生,引起尺神经卡压磨损,这是肘管综合征最常见的病因;其他病因还包括慢性骨关节炎,占位病变和先天异常;尺神经可被机械性卡压和磨损,出现慢性缺血缺氧,导致肘管综合征的发生;详细的体格检查和术前的肌电图检查是诊断肘管综合征的主要手段,在诊断时应注意该病与其他部位迟发性尺神经麻痹的鉴别。  相似文献   
43.
胸椎黄韧带骨化症的外科治疗   总被引:3,自引:0,他引:3       下载免费PDF全文
目的探讨胸椎黄韧带骨化症的诊断与手术治疗方法,分析其手术时机、手术技巧、手术效果及并发症处理。方法回顾性总结56例患者的外科治疗过程,采用胸椎管后壁切除减压及侧后方入路,术中体感诱发电位监护。结果术后55例经随访1年以上,1例随访2个月。39例,良8例,可5例,差4例。结论胸椎黄韧带骨化所致的脊髓压迫症须早期手术治疗,可根据不同情况选择胸椎管后壁切除减压及侧后方入路的次环状减压的手术方式。  相似文献   
44.
45.
Background : Many recent reports of the results of decompression of the median nerve in the carpal tunnel have concentrated on only one aspect of recovery (numbness, grip etc.), and there are no reports of a comprehensive study of outcome. The aim of the present study was to review comprehensively the results of the direct visualization method of decompression of the carpal tunnel and to compare them with the published results of endoscopic release. Methods : Patients' perceptions of the severity of pain, numbness and paraesthesiae due to carpal tunnel syndrome (CTS), before and after open carpal tunnel release (CTR) in 188 hands were reviewed retrospectively at a minimum time of follow-up of 18 months. Motor and sensory testing, provocation testing and measurement of scar tenderness in 135 hands were performed at a clinical review. Results : Subjective results showed that 70% experienced a reduction in the severity of pain after CTR, 78% of hands experienced a reduction in the severity of paraesthesiae and 77% experienced a reduction in the severity of numbness. A total of 49% had improvements in all three symptoms after CTR. At the clinical review, sensory testing revealed that 59% of hands had normal or slightly diminished light touch, 35% had normal static two-point discrimination and 61% had normal dynamic two-point discrimination. Results for Tinel's test, Phalen's test and pressure provocation testing were positive in 10% of hands. There was no scar tenderness in 38%, no persisting thenar atrophy in 90%. Normal grip strength was found in 93% and 91% had normal pinch strength. Conclusions : It was concluded that open carpal tunnel release remains a safe and reliable treatment for carpal tunnel syndrome. The very low incidence of serious complications from the open technique of CTR, when compared with endoscopic CTR as published by different authors in the literature, and the comparable clinical results, appears to make the open technique a safer and preferable option. However, a properly controlled trial of both techniques is necessary to compare them.  相似文献   
46.
An inbreeding program has been carried out with the Swiss sublines of Roman high- and low-avoidance rats since 1993. The present study reports the first experiments conducted with young animals of those inbred strains (RHA-I/Verh and RLA-I/Verh, respectively) from the sixth and seventh inbreeding generations. The results confirmed expected behavioral profiles. Compared to the RHA-I/Verh strain, RLA-I/Verh rats showed decreased entries into the illuminated central arena of an hexagonal tunnel maze, as well as decreased spontaneous locomotor activity and increased defecations, in two independent experiments. Young RLA-I/Verh females explored less than did their RHA-I/Verh counterparts during session 1 of a conditioned-fear experiment preceding shock administration, and in session 2 (conducted 24 h after the application of three footshocks), they showed greater conditioned behavioral inhibition (i.e., reduced amount of rearing), as well as higher defecation scores, than did RHA-I/Verh females.Karl Bättig tragically and unexpectedly died on December 27, 1996  相似文献   
47.
Summary Ossification of the ligamentum flavum has been recognised as a definite clinical entity as is ossification of the posterior longitudinal ligament. The incidence of both is high in Japan. This study demonstrates that the incidence of ossification of the ligamentum flavum in persons who have a kyphosis of the thoracic or lumbar spine is higher than in those who do not. It is considered that localised mechanical stress affecting the ligamentum flavum is a contributing factor to the development of ossification, together with the generalised factors which may favour bone formation. However, the aetiology of this lesion is still obscure as is that of ossification of the posterior longitudinal ligament.
Résumé L'ossification du ligament jaune représente une entité clinique définie, de même que celle du ligament longitudinal postérieur. Les deux affections sont fréquentes au Japon. Cette étude montre que l'ossification du ligament jaune s'observe plus souvent chez les sujets qui présentent une cyphose dorsale ou lombaire. On peut penser que les contraintes mécaniques localisées au ligament jaune constituent un facteur contribuant au développement de l'ossification, et s'ajoutant aux facteurs généraux susceptibles de favoriser la formation osseuse. Cependant, l'étiologie de cette affection demeure mystérieuse de même que l'ossification du ligament longitudinal postérieur.
  相似文献   
48.
以硫酸二乙酯(DES)诱变处理黄色短杆菌(Brevibacteriumflavum)XQ5122,得到突变株V3-36<Leu ̄1、α-AB ̄r、AHV ̄r),在10%葡萄糖培养基中可积累2.3%L-缬氨酸。以亚硝基胍(NTG)诱变V4-153,得到一株突变株(Leu ̄1、α-AB ̄r、AHV ̄r、2-TA ̄r),再进行单菌落分离,得到突变株ZQ-2,能在培养基中积累L-缬氨酸4.2%~4.5%,最高达5.57%.  相似文献   
49.
A common misconception attributes sparing of the flexor carpi ulnaris (FCU) in ulnar neuropathy at the elbow (UNE) to its innervating branch arising "at or above the elbow." We examined the relationship of FCU branches to the medial epicondyle (ME) and humeroulnar aponeurotic arcade (HUA) in 30 cadaver elbows. In only three did the first FCU branch arise at or proximal to the ME. In 36 UNE cases with fibrillations in the first dorsal interosseous, the FCU was normal in 10, mildly abnormal in 11, and severely abnormal in 15. FCU involvement correlated with the severity of the neuropathy and with whether compression was retroepicondylar or at the HUA. We conclude that sparing of the FCU in UNE is unrelated to the level of origin of its innervating branch, but rather is related to the internal neural topography and to the severity and level of compression.  相似文献   
50.
Ossification or calcification of the ligamentum flavum (LF) is relatively common in the middle and lower cervical, thoracic, and lumbar spine but extremely rare in the upper cervical region. This clinical fact suggests that there exist local factors promoting or preventing ossification or calcification of LF. However, little is known about the differences in the ultrastructure and cellular alterations of the LF between the different spinal levels, even in the cervical spine. With electron microscopy, we examined samples of LF collected surgically from the upper and lower cervical spine regions; we then studied the apoptotic appearance of ligament cells using a preferential labeling method. We found direct evidence of apoptosis of ligament cells in the LF. Apoptosis was more apparent in the upper region samples than in the lower region samples. The spaces around the normal fibroblasts were filled with thick collagen fibrils, but the collagen fibrils disappeared around the apoptotic bodies and thin fibrils were formed. The difference of the level of apoptosis may correlate to the ultrastructual difference of LF, and our data will benefit further investigations seeking to clarify the mechanism of various pathological conditions in the human LF.  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