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   28339篇
  免费   1843篇
  国内免费   676篇
耳鼻咽喉   201篇
儿科学   135篇
妇产科学   1874篇
基础医学   2412篇
口腔科学   243篇
临床医学   2472篇
内科学   965篇
皮肤病学   152篇
神经病学   1274篇
特种医学   1913篇
外科学   7140篇
综合类   4278篇
现状与发展   2篇
预防医学   1942篇
眼科学   25篇
药学   1546篇
  13篇
中国医学   1254篇
肿瘤学   3017篇
  2024年   54篇
  2023年   350篇
  2022年   721篇
  2021年   1184篇
  2020年   1008篇
  2019年   841篇
  2018年   1002篇
  2017年   951篇
  2016年   1019篇
  2015年   1034篇
  2014年   2183篇
  2013年   2116篇
  2012年   1875篇
  2011年   2019篇
  2010年   1765篇
  2009年   1601篇
  2008年   1437篇
  2007年   1480篇
  2006年   1261篇
  2005年   1033篇
  2004年   904篇
  2003年   738篇
  2002年   571篇
  2001年   543篇
  2000年   442篇
  1999年   399篇
  1998年   317篇
  1997年   285篇
  1996年   222篇
  1995年   222篇
  1994年   163篇
  1993年   170篇
  1992年   136篇
  1991年   103篇
  1990年   74篇
  1989年   70篇
  1988年   65篇
  1987年   71篇
  1986年   49篇
  1985年   82篇
  1984年   67篇
  1983年   40篇
  1982年   45篇
  1981年   33篇
  1980年   17篇
  1979年   25篇
  1978年   20篇
  1977年   16篇
  1976年   13篇
  1975年   8篇
排序方式: 共有10000条查询结果,搜索用时 34 毫秒
11.
12.
目的探讨前路椎体次全切除术和后路椎管扩大椎板成形术对脊髓型颈椎病(CSM)合并椎管狭窄症患者术后疗效及颈椎矢状位参数的影响。方法回顾性分析2010年3月—2015年8月收治的147例CSM合并椎管狭窄症患者的临床资料,其中80例行前路椎体次全切除术治疗(A组),67例行后路椎管扩大椎板成形术治疗(B组)。比较2种手术方法治疗前后日本骨科学会(JOA)评分、Cobb角及矢状位垂直距离(SVA)。将2组患者根据T_1倾斜角分别分为高T_1倾斜角(≥25°)亚组和低T_1倾斜角( 25°)亚组,对不同亚组之间的疗效及手术安全性进行比较。结果 2组术后JOA评分和Cobb角均高于术前,差异有统计学意义(P 0.05)。A组术后SVA低于术前,差异有统计学意义(P 0.05),B组术后SVA与术前相比差异无统计学意义(P 0.05)。A组术后JOA评分和Cobb角均高于B组,SVA低于B组,差异均有统计学意义(P 0.05)。A组中,高T_1倾斜角亚组和低T_1倾斜角亚组JOA评分改善效果和后凸畸形发生率比较差异无统计学意义(P 0.05);B组中,低T_1倾斜角亚组JOA评分改善效果和后凸畸形发生率优于高T_1倾斜角亚组,差异均有统计学意义(P 0.05)。结论相较于后路椎管扩大椎板成形术,前路椎体次全切除术治疗CSM合并椎管狭窄症临床疗效更佳,且有助于改善颈椎矢状位平衡;在高T_1倾斜角水平下,应尽可能选择前路椎体次全切除术。  相似文献   
13.
背景与目的:CD44分子是众多肿瘤细胞的标志分子,其表达水平与肿瘤细胞的恶性程度有关。该研究探讨CD44基因中的单核苷酸多态性(single nucleotide polymorphism,SNP)位点与云南汉族人群宫颈癌和非小细胞肺癌(nonsmall cell lung cancer,NSCLC)易感性的相关性。方法:选取了CD44基因中的两个SNP位点rs13347和rs8193,采用TagMan基因分型的方法,分析这两个多态性位点在497例宫颈癌患者和500例健康对照个体以及483例NSCLC患者和471例健康对照个体中的分布特征,并分析CD44基因中的多态性位点与云南汉族人群宫颈癌和NSCLC的相关性。结果:rs13347和rs8193位点等位基因和基因型在宫颈癌组和对照组中的分布频率的差异无统计学意义(P>0.05)。而在NSCLC组和对照组的比较中:rs13347和rs8193位点等位基因在NSCLC组和对照组中的分布频率的差异有统计学意义(P=0.020和P=0.004);这两个位点基因型在NSCLC组和对照组中分布频率的差异有统计学意义(P=0.027和P=0.020);其中rs13347位点等位基因C在NSCLC组中的分布频率显著高于对照组,可能是NSCLC发生的风险因素(OR=1.250,95% CI:1.035~1.509),rs8193位点等位基因C在对照组中的分布频率显著高于NSCLC组,可能是NSCLC发生的保护性因素(OR=0.768,95%CI:0.641~0.921)。单倍型分析结果显示,rs13347C-rs8193T和rs13347T-rs8193C在NSCLC组和对照组中的分布频率差异有统计学意义(P=0.003和0.022);该结果说明单倍型rs13347C-rs8193T可能是云南汉族人群NSCLC发生的风险性因素(OR=1.316,95%CI:1.096~1.579)。结论:CD44基因中的两个SNP位点rs13347和rs8193可能与云南汉族人群宫颈癌发病风险无关,而可能与云南汉族人群NSCLC具有相关性。  相似文献   
14.
Human leukocyte antigens (HLA) alleles may affect the development of cervical cancer through immunologic control of human papillomavirus (HPV). The association between HLA-DQB1 alleles and risk of cervical cancer has been extensively studied, but the results obtained remain inconsistent. To explore a more extensive role of HLA-DQB1 alleles on cervical cancer risk, we carried out a meta-analysis including 4862 cases and 8988 controls from 22 published studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The overall results suggested that HLA-DQB1*02 (OR = 0.91, 95% CI = 0.82–0.99), *03 (OR = 0.85, 95% CI = 0.74–0.97) and *0603 (OR = 0.62, 95% CI = 0.53–0.72) had a significantly association with decreased cervical cancer risk. In contrast, DQB1*05 (OR = 1.18, 95% CI = 1.01–1.38), *0301 (OR = 1.14, 95% CI = 1.06–1.23) and *0402 (OR = 1.31, 95% CI = 1.04–1.64) conferred a significantly higher risk to cervical cancer. Moreover, a significantly association with increased or decreased cervical cancer risk was found among Europeans and Asians after stratification of the HLA-DQB1 alleles by ethnicity. These findings supported that the HLA-DQB1 alleles may contribute to genetic susceptibility of cervical cancer. Further studies with a greater number of cases are expected to confirm our results.  相似文献   
15.
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019  相似文献   
16.
目的:探讨保妇康凝胶联合诺氟沙星治疗宫颈糜烂的临床效果。方法将100例宫颈糜烂患者根据随机数字表法分为观察组和对照组各50例。观察组给予保妇康凝胶和诺氟沙星联合治疗,对照组单独给予治糜灵栓治疗,比较两组患者临床症状的变化,并对临床疗效进行评价。结果观察组治愈率为86.00%,明显高于对照组的74.00%,临床症状评分改善较对照组明显,且其临床症状消失的时间短于对照组,差异均有统计学意义(P<0.05)。结论保妇康凝胶与诺氟沙星合用比治糜灵栓治疗宫颈糜烂效果更佳,且治愈时间上明显较优,值得临床上推广应用。  相似文献   
17.
The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction.  相似文献   
18.
BackgroundCervical spondylodiscitis is a rare but severe complication of pharyngeal surgery.Material and methodsThis multicenter retrospective study reported all patients in the database of the French head and neck tumor study group (GETTEC) affected by cervical spondylodiscitis after transoral robotic surgery (TORS) for malignant pharyngeal tumor from January 2010 to January 2017.ObjectivesTo describe cases of post-TORS cervical spondylodiscitis, identify alarm signs, and determine optimal management of these potentially lethal complications.ResultsSeven patients from 6 centers were included. Carcinomas were located in the posterior pharyngeal wall. Tumor stage was T1 or T2. All patients had risk factors for spondylodiscitis. Mean time to diagnosis was 12.6 days. The interval between surgery and spondylodiscitis diagnosis ranged from 20 days to 4.5 months, for a mean 2.1 months. The most common symptom was neck pain (87%). Infections were polymicrobial; micro-organisms were isolated in 5 cases and managed by intravenous antibiotics, associated to medullary decompression surgery in 3 cases. Follow-up found favorable progression in 4 cases, and 3 deaths (mortality, 43%).ConclusionThis French multicenter study found elevated mortality in post-TORS spondylodiscitis, even in case of limited resection. Surgeons must be aware of this complication and alerted by persistent neck pain, fever, asthenia, impaired or delayed posterior pharyngeal wall wound healing or elevation of inflammatory markers. MRI is the most effective diagnostic radiological examination.  相似文献   
19.
目的:探讨绝经后妇女高级别宫颈上皮内瘤变行宫颈环形电切术(LEEP)诊治的临床价值。方法:选择2017年2月-2018年12月于北京妇产医院妇科微创中心因宫颈高级别鳞状上皮内病变(HSIL)行LEEP术的患者共142例,其中绝经组40例,未绝经组102例。收集2组患者的液基薄层细胞学检查(TCT)、高危型人乳头瘤病毒(HPV)检测、阴道镜检查及其活检病理结果、LEEP术后病理结果、切缘病变情况,并将上述检查结果进行组间比较。结果:2组患者阴道镜下宫颈转化区类型比较,差异有统计学意义(χ~2=28.658,P=0.000)。绝经组阴道镜活检与LEEP术后病理符合率为50.00%(20/40),未绝经组符合率为51.96%(53/102),2组差异无统计学意义(χ~2=0.044,P=0.854)。绝经组1例LEEP术后病理升级为宫颈癌,未绝经组1例LEEP术后病理升级为原位腺癌。绝经组术后病理切缘阳性8例(20.00%),未绝经组术后病理切缘阳性16例(15.69%),2组比较差异无统计学意义(χ~2=0.381,P=0.537)。2组患者术后TCT检查比较及高危型HPV感染情况比较,差异均无统计学意义(均P>0.05)。结论:LEEP手术适用于宫颈无明显萎缩的绝经后妇女高级别宫颈上皮内瘤变的诊治,以避免对宫颈病变的漏诊和过度治疗。  相似文献   
20.
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