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   12517篇
  免费   1697篇
  国内免费   382篇
耳鼻咽喉   97篇
儿科学   270篇
妇产科学   127篇
基础医学   842篇
口腔科学   238篇
临床医学   1327篇
内科学   1432篇
皮肤病学   164篇
神经病学   603篇
特种医学   239篇
外国民族医学   5篇
外科学   589篇
综合类   2678篇
预防医学   3322篇
眼科学   150篇
药学   985篇
  8篇
中国医学   912篇
肿瘤学   608篇
  2024年   18篇
  2023年   251篇
  2022年   492篇
  2021年   770篇
  2020年   894篇
  2019年   448篇
  2018年   394篇
  2017年   557篇
  2016年   545篇
  2015年   503篇
  2014年   1109篇
  2013年   1025篇
  2012年   1040篇
  2011年   1100篇
  2010年   809篇
  2009年   644篇
  2008年   599篇
  2007年   573篇
  2006年   470篇
  2005年   377篇
  2004年   299篇
  2003年   255篇
  2002年   193篇
  2001年   203篇
  2000年   149篇
  1999年   112篇
  1998年   90篇
  1997年   66篇
  1996年   66篇
  1995年   64篇
  1994年   63篇
  1993年   48篇
  1992年   34篇
  1991年   29篇
  1990年   44篇
  1989年   33篇
  1988年   25篇
  1987年   31篇
  1986年   23篇
  1985年   21篇
  1984年   18篇
  1983年   18篇
  1982年   21篇
  1981年   9篇
  1980年   10篇
  1979年   14篇
  1978年   9篇
  1977年   9篇
  1976年   12篇
  1974年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的分析江苏省启东市1972—2016年胃癌死亡流行特征。方法收集启东市1972—2016年恶性肿瘤死亡登记数据库及历年人口资料, 计算死亡率、中国人口标化率(中标率)、世界人口标化率(世标率)、35~64岁截缩率、0~74岁累积死亡率、累积死亡风险、变化百分比、死亡率年均变化百分比。结果 1972—2016年启东市胃癌死亡例数为15 863例, 占全部恶性肿瘤死亡例数的16.04%, 胃癌死亡率为31.37/10万, 中标率为12.97/10万, 世标率为21.39/10万, 35~64岁截缩死亡率为28.86/10万, 0~74岁累积死亡率为2.54%, 胃癌死亡累积风险为2.51%。男性死亡10 114例, 男性死亡率、中标率、世标率分别为40.53/10万、17.98/10万和30.13/10万;女性死亡5 749例, 女性死亡率、中标率、世标率分别为22.45/10万、8.52/10万和13.92/10万。25岁以下各年龄组的死亡率<1/10万, 死亡率随年龄的增长而升高, 50~岁组达到并超过人群的平均死亡率水平, 80~岁组达到死亡高峰。1972—2016年间胃癌死...  相似文献   
2.
目的: 应用锥形束CT(CBCT)分析多生牙相关特征,为临床诊疗提供参考。方法: 选择2019年1月—2020年12月内蒙古医科大学附属医院口腔科经CBCT确诊的234颗多生牙作为研究对象,分析其生长发育特征及继发影响。采用SPSS 25.0软件包对数据进行统计学处理。结果: 患者平均年龄11.16±7.61岁,以7~12岁最多。男女比例为1.6∶1。汉族占85.0%。多数单侧生长,数量多为1颗。多生牙生长区域多数为上颌骨切牙区,下颌骨前磨牙区。切牙区多生牙多见于7~12岁,尖牙区和前磨牙区多见于13~18岁,磨牙区多见于≥19岁。切牙区多生牙好发于男性,以圆锥形为主;其余区域多生牙好发于女性,以结节形为主,差异均有统计学意义(P<0.05)。发育情况为≥19岁年龄组高于其他3组,磨牙区高于其他区域,上颌骨高于下颌骨,差异均有统计学意义(P<0.05);位于两恒牙牙根之间的多生牙高于其他3组,差异无统计学意义(P>0.05)。萌出情况为部分牙根形成和完全形成高于牙冠形成,正向高于其他方向;位于两恒牙牙根之间的多生牙高于其他3组,差异均有统计学意义(P<0.05)。继发影响为各生长区域及位于恒牙唇侧、根尖部和两恒牙牙根之间的多生牙主要影响邻近恒牙,位于恒牙腭侧的多生牙多数无继发影响,差异均有统计学意义(P<0.05)。结论: CBCT可精确分析多生牙相关特征,利于临床制定完善诊疗方案,提高治疗效果。  相似文献   
3.
目的:探索真实世界中生脉注射液治疗冠心病心绞痛的临床特征及合并用药规律。方法:对2214例冠心病心绞痛患者医院信息系统中的临床特征数据进行描述性分析,并利用关联规则算法挖掘生脉注射液治疗冠心病心绞痛的联合用药规律。结果:男性患者共996例(44.99%),少于女性的1196例(54.02%);患者的平均年龄(72.1±12.36)岁,其中66~85岁的患者最多,共1544例(69.74%);住院病情以一般者为最多,共945例(42.68%);患者的平均住院天数为(21.96±16.26)d,其中住院天数在15~28 d的患者最多,共865例(39.07%);本研究中生脉注射液用药途径主要为静脉滴注(共1768例,占79.86%);通过静脉滴注的用药方式应用生脉注射液的单次剂量平均为(54.09±18.09)mL;其中41~60 mL者最多,共1008例(57.01%);生脉注射液的平均用药(5.4±6.49)d;生脉注射液治疗冠心病心绞痛最常用的合并用药组合为丹红注射液→单硝酸异山梨酯、速效救心丸-丹红注射液→单硝酸异山梨酯、阿伐他汀→乙酰水杨酸、单硝酸异山梨酯-美托洛尔→乙酰水杨酸。结论:经过对冠心病心绞痛患者医院信息系统(HIS)数据的严格清洗以及标准化,可通过数据挖掘技术对其进行临床特征及用药规律的挖掘分析,并为临床医生提供一定的参考,具有重要的研究意义。  相似文献   
4.
BackgroundIdentifying the MIC wild-type distribution and its delineation of species targeted for receiving antimicrobial agent breakpoints is an important first step for determining clinical breakpoints. Having the main responsibility in the European Committee on Antimicrobial Susceptibility Testing (EUCAST) for characterizing the wild-type distributions and setting epidemiological cut-off values (ECOFFs), we explain the why, the how, and frequent misconceptions of wild-type MIC distributions and ECOFFs.ObjectivesTo clarify how wild-type MIC distributions and ECOFFs for agents and important target organisms are defined and determined and why these are important tools in microbiology, as well as to point to common misunderstandings and inappropriate use.SourcesThe EUCAST database of >40 000 MIC distributions; publications addressing the definition of wild-type MIC distributions, and ECOFFs in bacteria and fungi; and the EUCAST Standard Operating Procedure 10 Documents published by the European Centre for Disease Control and the European Food Safety Agency.ContentThe rationale for defining wild-type distributions and ECOFFs is explained. Setting breakpoints that bisect wild-type MIC distributions leads to poor methodological reproducibility and poor correlation between clinical outcome and susceptibility testing results. The methods applied by EUCAST to select distributions for aggregation and website display are described, highlighting the importance of incorporating data from multiple sources and methods. The methods used by EUCAST to estimate ECOFFs are outlined. Finally, the common misunderstandings of these processes are addressed.ImplicationsThe international community needs to agree on the phenotypic definitions of wild-type distributions. Systematic methods for developing and applying ECOFFs are essential to the conduct of phenotypic antimicrobial susceptibility testing and interpretation, which will remain the dominant laboratory method for the foreseeable future.  相似文献   
5.
BackgroundInflammation surrounding the coronary arteries can be non-invasively assessed using pericoronary adipose tissue attenuation (PCAT). While PCAT holds promise for further risk stratification of patients with low coronary artery disease (CAD) prevalence, its value in higher risk populations remains unknown.MethodsCORE320 enrolled patients referred for invasive coronary angiography with known or suspected CAD. Coronary computed tomography angiography (CCTA) images were collected for 381 patients for whom clinical outcomes were assessed 5 years after enrollment. Using semi-automated image analysis software, PCAT was obtained and normalized for the right coronary (RCA), left anterior descending (LAD), and left circumflex arteries (LCx). The association between PCAT and major adverse cardiovascular events (MACE) during follow up was assessed using Cox regression models.ResultsThirty-seven patients were excluded due to technical failure. For the remaining 344 patients, median age was 62 (interquartile range, 55–68) with 59% having ≥1 coronary artery stenosis of ≥50% by quantitative coronary angiography. Mean attenuation values for PCAT in RCA, LAD, and LCx were ?74.9, ?74.2, and ?71.2, respectively. Hazard ratios and 95% confidence intervals (CI) for normalized PCAT in the RCA, LAD, and LCx for MACE were 0.96 (CI: 0.75–1.22, p ?= ?0.71), 1.31 (95% CI: 0.96–1.78, p ?= ?0.09), and 0.98 (95% CI: 0.78–1.22, p ?= ?0.84), respectively. For death, stroke, or myocardial infarction only, hazard ratios were 0.68 (0.44–1.07), 0.85 (0.56–1.29), and 0.57 (0.41–0.80), respectively.ConclusionsIn patients referred for invasive coronary angiography with suspected CAD, PCAT did not predict MACE during long term follow up. Further studies are needed to understand the relationship of PCAT with CAD risk.  相似文献   
6.
Cancer incidence and mortality are increasing globally, leading to its rising status as a leading cause of death. The Go-Ichi-Ni-San (GINS) complex plays a crucial role in DNA replication and the cell cycle. The GINS complex consists of four subunits encoded by the GINS1, GINS2, GINS3, and GINS4 genes. Recent findings have shown that GINS2 expression is upregulated in many diseases, particularly tumors. For example, increased GINS2 expression has been found in cervical cancer, gastric adenocarcinoma, glioma, non-small cell lung cancer, and pancreatic cancer. It correlates with the clinicopathological characteristics of the tumors. In addition, high GINS2 expression plays a pro-carcinogenic role in tumor development by promoting tumor cell proliferation and migration, inhibiting tumor cell apoptosis, and blocking the cell cycle. This review describes the upregulation of GINS2 expression in most human tumors and the pathway of GINS2 in tumor development. GINS2 may serve as a new marker for tumor diagnosis and a new biological target for therapy.  相似文献   
7.
8.
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time.  相似文献   
9.
目的分析淄博市近年来肺结核流行特征,为制定“十四五”期间全市结核病防控策略和措施提供科学依据。方法采用描述性流行病学研究方法,对《中国疾病预防控制信息系统-结核病信息系统》登记的2012—2020年淄博市肺结核患者信息进行统计分析。结果2012—2020年淄博市共登记肺结核患者全市肺结核患者12706例,登记发病率逐年下降(F=53.348,P<0.001),年均30.45/100000万,死亡率无明显变化;地区分布上,发病率总体淄博北部高于南部,中部交叉分布;时间分布上,历年各月均有肺结核病例发生,总体呈先上升后下降再上升趋势(F=8.856,P=0.006<0.01),呈现1~2月、10月两个低谷及5~6月、12月两个高峰;人群分布上,以本地病例为主(82.38%),男性发病率约为女性的2.09倍(χ2=31.441,P<0.001),0~14岁少年儿童发病率最低,65岁及以上老年人发病率最高(61.02/100000万),患者职业以农民为主,占60.59%;患者来源以追踪为主,2016年起超过50.00%。结论淄博市结核病疫情总体平稳,发病率逐年下降,呈现一定季节性特征,患者以男性居多,应特别关注农民和老年人群,进一步加强疫情高发区县危险因素研究工作。  相似文献   
10.
目的探讨N1站淋巴结检出数目与pT1~3N0M0非小细胞肺癌(NSCLC)患者临床病理特征及预后的关系。方法选择2013年1月至2015年3月在安徽医科大学附属省立医院接受肺癌根治术的pT1~3N0M0 NSCLC患者337例, 采用受试者工作特征(ROC)曲线的分析确定以N1站淋巴结检出数目预测pT1~3N0M0 NSCLC患者5年生存的最佳界值, 根据最佳界值分组, 分析N1站淋巴结检出数目与pT1~3N0M0 NSCLC患者临床病理特征及预后的关系。结果 337例患者共检出N1站淋巴结1 321枚, 每例患者平均3.9枚。中位生存时间为42.0个月, 1、3、5年生存率分别为82.2%、57.1%和24.9%。ROC曲线分析显示, 以N1站淋巴结检出数目预测pT1~3N0M0 NSCLC患者5年生存的最佳界值4.5枚, 取整数后, 以N1站淋巴结检出数目为5枚作为界值, 将患者分为检出淋巴结<5枚组(212例)和检出淋巴结≥5枚组(125例)。检出淋巴结≥5枚组接受辅助化疗的患者比例为19.2%, 高于检出淋巴结<5枚组(9.0%, P=0.007), 两组患者其他临...  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