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   19871篇
  免费   2537篇
  国内免费   700篇
耳鼻咽喉   150篇
儿科学   60篇
妇产科学   2088篇
基础医学   2068篇
口腔科学   335篇
临床医学   2177篇
内科学   955篇
皮肤病学   66篇
神经病学   795篇
特种医学   628篇
外国民族医学   24篇
外科学   2405篇
综合类   4151篇
现状与发展   8篇
预防医学   1093篇
眼科学   38篇
药学   972篇
  21篇
中国医学   1329篇
肿瘤学   3745篇
  2024年   38篇
  2023年   313篇
  2022年   525篇
  2021年   879篇
  2020年   828篇
  2019年   653篇
  2018年   597篇
  2017年   906篇
  2016年   997篇
  2015年   995篇
  2014年   1736篇
  2013年   1464篇
  2012年   1392篇
  2011年   1523篇
  2010年   1224篇
  2009年   1073篇
  2008年   990篇
  2007年   1066篇
  2006年   942篇
  2005年   723篇
  2004年   575篇
  2003年   555篇
  2002年   445篇
  2001年   397篇
  2000年   251篇
  1999年   220篇
  1998年   220篇
  1997年   185篇
  1996年   177篇
  1995年   144篇
  1994年   145篇
  1993年   102篇
  1992年   96篇
  1991年   77篇
  1990年   75篇
  1989年   66篇
  1988年   62篇
  1987年   47篇
  1986年   57篇
  1985年   63篇
  1984年   57篇
  1983年   42篇
  1982年   56篇
  1981年   31篇
  1980年   30篇
  1979年   16篇
  1978年   20篇
  1977年   11篇
  1976年   9篇
  1972年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
[目的]探讨伴有上肢局部水肿的颈椎病患者的发病机理和与手术颈椎减压的关系。[方法]总结分析4a来收治的10例伴有上肢局部水肿的颈椎病人,其中脊髓型颈椎病7例,神经根型颈椎病2例,后纵韧带骨化型1例,7例行前路椎体次全切减压植骨内固定,1例行前路椎体次全切+单间隙间盘摘除植骨内固定,2例行后路减压植骨内固定,术后观察患者水肿消退情况。[结果]10例病人上肢局部水肿不同程度消退,前路手术者较后路手术者消退快。[结论]颈椎病患者上肢水肿的发生与颈交感神经受激惹有关,通过前路或后路颈椎管减压,去除颈椎不稳、椎间盘突出、骨赘等交感神经受激惹因素,水肿可逐步消退。  相似文献   
82.
The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.  相似文献   
83.
The reliability and applicability of colposcopically directed cervical punch biopsy was assessed in a sample of 170 paired punch and large loop excision of cervical transformation zone (LLETZ) specimens obtained from previously untreated women who had been selected for treatment on the basis of cytology and/or colposcopic findings and in whom the entire cervical transformation zone was visible. A single punch biopsy was taken immediately before the LLETZ, and all the specimens were reviewed by a single pathologist. Nine (5.3%) punch biopsies were inadequate. In terms of whether or not there was cervical intraepithelial neoplasia (CIN), the chance-corrected kappa analysis rated overall agreement as poor (kappa = 0.21, 95% confidence limits 0.02-0.39), whereas in terms of histologic grade, it was fair to moderate (kappa = 0.32, 95% confidence limits 0.23-0.42). Punch biopsy tended to underestimate the disease. The sensitivity and specificity of colposcopically directed punch biopsy for the detection of high-grade CIN was 74% and 91%, respectively, with positive- and negative predictive values of 97% and 48%, respectively. Two microinvasive and two intraepithelial glandular lesions were missed on punch biopsy. Punch biopsy should be avoided when high-grade disease is suspected.  相似文献   
84.
In this study, we evaluated the presence of human papillomavirus (HPV) DNA in organs of the female upper genital tract, using nine hysterectomy and salpingo-oophorectomy specimens affected by HPV-positive invasive cervical carcinomas, to establish if cervical HPV infection can spread to upper tracts of the female genital system. HPV DNA was evaluated by polymerase chain reaction (PCR) in all cervical carcinomas as well as in all tracts of the genital system. Then, these data were compared with the results obtained from PCR study of five other hysterectomy and salpingo-oophorectomy specimens (control cases). The criteria used for selection of the control cases were informed consent of the patients for research at the time of surgery, absence of neoplasms, absence of any anatomic lesion caused by HPV in cervix, and external genitalia. All selected cases were squamous cervical carcinomas. PCR analysis revealed HPV DNA in all cases of cervical carcinoma. The HPV DNA was detected as weak positivity on PCR analysis in other organs of the genital system. However, the distribution of HPV DNA varied in the various cases and in the different tracts of the same hysterectomy and salpingo-oophorectomy specimen. We believe that the HPV DNA, detected as a weakly positive signal, in the upper genital tract of patients who have a cervical squamous carcinoma could be a reflection of a latent HPV infection, as well as a sign of the existence of micrometastases containing HPV DNA, which cannot be detected by conventional histologic techniques.  相似文献   
85.
目的观察颈丛阻滞下行颈动脉内膜剥脱术的效果.方法 28名ASAⅡ~Ⅲ级患者行32例颈动脉内膜剥脱术,采用深浅丛联合阻滞,观察围术期血液动力学指标变化,分流管放置率和并发症情况.结果 麻醉后血压和心率与麻醉前相比差异有显著性(P<0.05),其它时点与麻醉前相比差异无显著性(P>0.05).颈动脉夹闭前后收缩压和心率的波动性的差异无显著性(P>0.05).围术期高血压的发生率为50.0%,低血压6.25%,心动过速28.1%,心动过缓6.25%,分流管放置率6.25%.患者满意率84.4%.无1例改用全麻,无严重围术期并发症.结论颈丛阻滞是颈动脉内膜剥脱术安全、有效的麻醉方法.  相似文献   
86.
We report the case of a fracture separation of the articular pillar at the lower cervical spine. The trauma, following a brass knuckles, repeats almost in an experimental way the rotation and extension mechanism given in literature for the genesis of such injuries. From the admission in the orthopaedic service to the surgery, the development went in a characteristic way towards a rotatory displacement. Received: 12 July 2002, Accepted: 18 August 2002 Correspondence to: R. Massicot  相似文献   
87.
颈椎椎体次全切除钛网钉板系统的临床应用   总被引:1,自引:1,他引:0       下载免费PDF全文
目的探讨颈椎前路椎体次全切除钛网钉板植骨融合的临床效果。方法自2001年3月~2003年3月间应用颈前路椎体次全切除钛网植骨融合及钉板固定治疗颈椎管狭窄性疾病22例,其中4例患者行2椎体次全切除3节椎间隙减压手术。术后观察减压、固定、融合及神经功能恢复情况,并行X线摄片或CT扫描检查。结果患者获6~12个月随访,神经功能得到不同程度改善,无加重情况。椎间隙高度无丢失、无成角,均获得骨性融合。术后3d在颈围领固定下下床活动,4周后可恢复较轻工作。结论此术式可避免传统手术方法的缺点,即不取自体髂骨,融合率高,稳定性好,并减压彻底,疗效好,是一种值得推广的新技术。  相似文献   
88.
Wheat germ agglutinin-horseradish peroxidase conjugate was injected in the unilateral superior cervical ganglion (SCG), and the projection pathways of postganglionic sympathetic nerve fibers innervating the cochlea were traced in the rat. The labeled axons advanced along the internal carotid artery (ICA), and a few advanced caudally in the major petrosal nerve (MPN) and entered the facial nerve, while the majority ran rostral to the pterygopalatine ganglion at the point where they crossed the MPN in the carotid canal. The rest of the labeled fibers remained on the surface of the ICA and advanced to the cranial cavity. Most of the labeled fibers along the facial nerve joined the cochlear nerve and finally reached the osseous spiral lamina through the spiral ganglion. Some of the labeled fibers ran along the anterior inferior cerebellar artery from the basilar artery which was previously thought to have been the only pathway. We could not find any labeled fiber on the modiolar artery from anterior inferior cerebellar artery in the cochlea. These observations are consistent with our hypothesis that the sympathetic fibers innervating the neural tissues or related structures follow nerve fibers and meninges as matrices of projection pathways rather than arteries.  相似文献   
89.
用尿谷胱甘肽过氧化物酶评定颈椎病的康复疗效   总被引:2,自引:0,他引:2  
测定了44例颈椎病患者康复前后尿液中谷胱甘肤过氧化物酶(GSH-Px)活力的变化。患者在治疗前,尿中GSH-Px活力为1080±310U/L((?)±s),与健康对照组相比差异有高度显著性(P<0.001)。推拿和颈牵治疗后尿中GSH—Px活力平均下降38.8%,且下降幅度和疗效之间有着明显的平行关系。据此,我们认为颈椎病的发病可能和体内自由基代谢紊乱有关,同时认为,无创伤的尿GSH—Px活力测定可以作为颈椎病康复疗效评定的客观指标,从而为颈椎病康复疗效的评定提供科学的生化依据。  相似文献   
90.
初产妇30例,用亲水性聚氯酯泡沫宫颈扩张棒(简称“扩张棒”)作人工剥膜与破膜加催产素引产前扩张宫颈,同时以条件类同初产妇30例进行对照。扩张棒组置棒前宫颈成熟度评分为2.93±0.91,对照组为3.7±0.88,两组无显著差异:扩张后宫颈评分为6.13±1.22,与扩张前有显著差异(P<0.05)。扩张棒组引产成功率为92.6%,而对照组为64.3%,差异非常显著(P<0.01),同时能缩短产程。本组用扩张棒组引产的30例,无一例发生产时、产后感染。  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