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   11306篇
  免费   792篇
  国内免费   448篇
耳鼻咽喉   118篇
儿科学   279篇
妇产科学   281篇
基础医学   1933篇
口腔科学   94篇
临床医学   865篇
内科学   1563篇
皮肤病学   116篇
神经病学   800篇
特种医学   179篇
外科学   560篇
综合类   1638篇
现状与发展   1篇
一般理论   7篇
预防医学   2021篇
眼科学   99篇
药学   726篇
  8篇
中国医学   575篇
肿瘤学   683篇
  2024年   20篇
  2023年   200篇
  2022年   427篇
  2021年   410篇
  2020年   459篇
  2019年   370篇
  2018年   379篇
  2017年   352篇
  2016年   342篇
  2015年   464篇
  2014年   850篇
  2013年   889篇
  2012年   682篇
  2011年   849篇
  2010年   627篇
  2009年   662篇
  2008年   649篇
  2007年   608篇
  2006年   570篇
  2005年   450篇
  2004年   370篇
  2003年   318篇
  2002年   203篇
  2001年   201篇
  2000年   174篇
  1999年   143篇
  1998年   102篇
  1997年   90篇
  1996年   69篇
  1995年   80篇
  1994年   65篇
  1993年   60篇
  1992年   50篇
  1991年   46篇
  1990年   43篇
  1989年   24篇
  1988年   24篇
  1987年   21篇
  1986年   16篇
  1985年   31篇
  1984年   24篇
  1983年   14篇
  1982年   15篇
  1981年   22篇
  1980年   18篇
  1979年   18篇
  1978年   12篇
  1977年   6篇
  1976年   7篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
目的 探讨GSTM1基因多态性与膀胱癌遗传易感性的关系。 方法 采用PCR技术 ,以病例 对照研究方法 ,对 6 9例膀胱癌患者和 88例健康对照者的GSTM 1基因型进行检测。 结果 膀胱癌患者GSTM1空白基因型频率为 5 8% ,对照组为 4 1% ,两组比较差别有显著性意义 (χ2 =4 .5 1,P <0 .0 5 ) ,OR值为 2 .0 (95 %CI =1.0 5~ 3.79)。吸烟者中 ,患者组GSTM1空白基因型频率为71% ,对照组为 2 4 % ,两组比较差别有显著性意义 (χ2 =2 2 .6 ,P <0 .0 1) ,OR值为 8.3(95 %CI =3.34~ 2 0 .6 5 )。以GSTM1非空白型 /不吸烟者为参照 ,GSTM1空白型 /吸烟者的OR值为 4 .6 4 (95 %CI=1.86~ 11.37,χ2 =11.6 3,P <0 .0 1) ,差别有显著性意义。 结论 GSTM 1基因多态性与膀胱癌易感性有关 ,在膀胱癌的发生发展中与吸烟协同起作用  相似文献   
82.
基因测序是实现肿瘤精准医疗的基础手段,可辅助肿瘤诊断、判断患者预后、指导靶向药物治疗等。近年来,基因测序技术已广泛应用于甲状腺癌的临床诊治工作中。但截至目前,不同医疗中心对基因测序适应证的把控、报告解读水平,以及各测序平台的检测结果可靠性参差不齐。本文通过分析基因检测在甲状腺癌诊治中应用的现状与问题,结合笔者个人临床经验,探讨基因检测在甲状腺癌诊治全程管理中的特殊性及其价值。  相似文献   
83.
【摘要】 目的 探讨DNA损伤修复基因XRCC1 Arg194Trp基因多态性与中国人群结直肠癌易感性的关系。方法 按照制定的检索策略,通过计算机和手工检索相关数据库,收集有关XRCC1 Arg194Trp基因多态性与中国人群结直肠癌易感性的病例对照研究,按照纳入标准筛选文献、并从纳入文献中提取相关数据,以病例组和对照组基因型分布的比值比(OR)为效应指标,应用Stata12.0软件进行异质性检验,对各研究原始数据进行Meta合并,并行敏感性分析和发表偏倚的评估。结果〓本Meta分析共纳入11项病例对照研究,累积病例2710例,对照3567例。根据各研究间的异质性,采用不同的模型进行合并效应量。在等位基因比较(T vs C) [OR(95%CI)=1.18(1.01-1.39),P=0.036],纯合子比较模型(TT vs CC) [OR (95%CI)=1.39(1.02-1.90),P=0.038],显性模型(CT/TT vs CC) [OR(95%CI)=2.24(1.78-2.82),P<0.001] 以及隐性模型 (TT vs CT/CC) [OR(95%CI)=1.23(1.02-1.49),P=0.030]均存在显著的统计学差异。发表偏倚评估均未见明显偏倚。结论〓在中国人群中,携带突变等位基因T或突变纯合子TT的人群罹患CRC的风险有所升高,而在显性遗传模型中,携带有CT/TT基因型的人群其CRC的易感性明显升高。  相似文献   
84.
Glutathione peroxidase 1 (GPX1) is a ubiquitously expressed selenium-dependent enzyme that protects cells against oxidative damage by reducing hydrogen peroxide and a wide range of organic peroxides. Some epidemiological studies have correlated low GPX activity or particular GPX1 polymorphisms with enhanced risk of cancer, although these correlations have not been consistently observed in all populations. Therefore, we conducted the present study to evaluate the possible association of GPX1 Pro198Leu polymorphism and erythrocyte GPX activity with the risk of developing prostate cancer and to clarify whether erythrocyte GPX activity levels were correlated with the GPX1 Pro198Leu genotype in the Macedonian population. The GPX1 Pro198Leu genotype was determined in 82 prostate cancer cases and 123 control individuals. We found an overall protective effect of the variant Leu allele of the GPX1 polymorphism on the prostate cancer risk. Heterozygous carriers of the variant Leu allele had a significantly lower risk of prostate cancer compared with homozygous wild-type individuals (OR, 0.38; 95% CI, 0.20–0.75; P = 0.004). Erythrocyte GPX activity was analyzed in 73 cases and 91 controls. The erythrocyte GPX activity in the cancer group was lower than in the healthy controls. Additionally, we compared the erythrocyte GPX activity in the control group of 90 subjects and found no significant differences by genotype. These findings suggest that individual susceptibility of prostate cancer may be modulated by GPX1 polymorphism and that the combination of genetic factors involved in oxidative response with environmental carcinogens may play an important role in prostate carcinogenesis.  相似文献   
85.
Introduction  The 22nd Student World Winter Games took place in January 2005 in Innsbruck and Seefeld, Austria. Exactly 1,500 athletes of 50 nationalities competed in 69 events in ten winter sports. A total number of 750 functionaries, 800 volunteers and 85,000 spectators participated in the second largest winter sports event behind the Olympic winter games. Aim  The aim of this study was to evaluate the needed resources to ensure traumatological care for an event of that size. Material  At the medical “call-center” all consultations, as well as patient data, diagnosis, and medical treatment were recorded using a preset protocol. Further, all patients treated in the University Hospital Innsbruck were registered with an emphasis on trauma patients. Results  Forty-eight of 65 patients transported to the hospital as a result of the Universiade were trauma patients, 37 of whom were athletes. The gender distribution was 34:14 (m:f). Ice hockey players had the highest rate of injury (25% of all injured athletes), followed by alpine skiers (20.8% of injured athletes). The highest ISS was nine. Forty-three patients got ambulatory treatment, five were admitted to the hospital and surgical treatment was conducted in three cases. Mean patient number was 4.8 per day. No additional personnel, structural, or technical hospital resources were needed to accommodate a large winter sports event like the Universiad. Thus, a level-B trauma center with an emergency room and independent traumatological department with around the clock surgical capability seems to be sufficient to provide traumatological care for an event of this size if the possibility of patient transport to a larger facility exists in the case of catastrophic events.  相似文献   
86.

Background

The impact of newer breast imaging technologies and genetic testing on the detection of breast cancer in women age 40 and younger remains unknown.

Methods

A records review identified 628 women age 40 and younger diagnosed with breast cancer from 1996 to 2008. Patient and tumor characteristics, means of diagnosis, imaging results, and genetic testing were examined.

Results

Tumors were first detected by self-examination in 71%, with a median invasive tumor size of 2.0 cm. Imaging performed at or after diagnosis visualized most tumors; mammography visualized 86%, magnetic resonance imaging (MRI) visualized 96%, and mammography plus MRI visualized more than 98% of tumors. For 81% of patients, the mammogram at diagnosis was their first mammogram. Although 50% had a family history of breast or ovarian cancer, few underwent genetic testing before their cancer diagnosis; 61 of 247 (25%) ultimately tested had a BRCA mutation.

Conclusions

Better use of genetic testing, mammography, and MRI could improve breast cancer detection in young women.  相似文献   
87.
Nephropathic cystinosis is a severe autosomal recessive inherited metabolic disease characterized by accumulation of free cystine in lysosomes. Cystinosis can lead to renal failure and multiorgan impairment. Only five cases of cystinosis with associated Bartter syndrome are reported in the literature, and no genetic evaluation has been reported. We describe two siblings with nephropathic cystinosis presenting with features of Bartter syndrome and their genetic pattern.  相似文献   
88.
目的 探讨P120catenin在胰腺癌中的表达及其基因T755G位点多态性与胰腺癌发病因素的关系.方法 分别应用RT-PCR及Western Blot方法检测52例胰腺癌及癌旁正常胰腺组织中P120catenin的表达水平;应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术对52例胰腺癌患者及60名正常对照的P120catenin基因T755G位点基因型分析.结果 胰腺癌组P120catenin mRNA及蛋白表达与癌旁正常胰腺组相比均减少,差异有统计学意义(P=0.000,P=0.002);P120catenin mRNA异常表达更多见于低分化者(P=0.033)、淋巴转移者(P=0.004)、血管侵犯者(P=0.022)和高PTNM分期者(P=0.003).胰腺癌患者P120catenin基因T755G位点基因型频率及等位基因频率与正常组相比,差异有统计学意义(P=0.008,P=0.016).与TT基因型相比,GG基因型可增加胰腺癌发病风险(OR=2.765,95%CI为1.312~3.958).结论 P120catenin低表达与胰腺癌淋巴结转移、血管侵犯、pTNM分期密切相关,提示其可能在胰腺癌侵袭、转移过程中起重要作用.P120catenin基因T755G多态性与胰腺癌的发生风险相关,有利于胰腺癌的早期诊断与预防.  相似文献   
89.
The effectiveness of organizational interventions in reducing the adverse consequences of work–family conflict has produced mixed findings. This paper examines the relationship between the use of organizational ‘family friendly’ resources (such as crèche facilities, flexible working hours, and job sharing), with levels of work–family conflict, and job and family satisfaction over time. Using structural equation modelling, these associations were tested in 398 employed men and women who each completed a self‐report questionnaire administered on two occasions. The use of organizational interventions directly predicted increased levels of concurrent (Time 1) work–family interference and increased levels of subsequent (Time 2) job satisfaction. Both organizational interventions and family interventions (i.e. support) positively predicted subsequent family satisfaction. The research demonstrates that the provision of organizational ‘family‐friendly’ practices will produce improved psychological outcomes for employees. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
90.
《中国现代医生》2020,58(28):143-146
目的 了解杭州地区地中海贫血的检出情况,探讨产检中筛查地中海贫血的意义,评价平均红细胞体积(MCV)、平均血红蛋白量(MCH)及血红蛋白电泳对地中海贫血进行产前筛查的价值。方法 以2019年2月~2020年3月在我院检查的3968例育龄期妇女为研究对象,进行血常规、血红蛋白电泳及β-地贫基因检测。结果 筛查3968例育龄期妇女,疑似α-地中海贫血或缺铁性贫血共有366例(9.22%),其中妊娠中晚期孕妇有255例;疑似β-地中海贫血共有19例(0.48%),其中有4例进行β-地贫基因检测,均被确诊为β-地中海贫血,分别为βIVS-II-654/βN 突变1例,βCD17/βN 突变2例,βCD41/42/βN 1例。结论 MCV、MCH及血红蛋白电泳可以对地中海贫血进行产前筛查,整体操作较为简便。加强地中海贫血筛查及检测,可以降低出生缺陷,对优生优育具有重要意义。  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