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   277562篇
  免费   23847篇
  国内免费   8943篇
耳鼻咽喉   2387篇
儿科学   9300篇
妇产科学   1897篇
基础医学   23655篇
口腔科学   4655篇
临床医学   31209篇
内科学   71882篇
皮肤病学   3415篇
神经病学   27694篇
特种医学   8471篇
外国民族医学   14篇
外科学   21787篇
综合类   41217篇
现状与发展   41篇
一般理论   12篇
预防医学   19947篇
眼科学   2772篇
药学   20247篇
  223篇
中国医学   13965篇
肿瘤学   5562篇
  2024年   289篇
  2023年   5401篇
  2022年   7110篇
  2021年   13185篇
  2020年   13676篇
  2019年   10774篇
  2018年   10514篇
  2017年   10709篇
  2016年   11153篇
  2015年   10845篇
  2014年   19666篇
  2013年   21651篇
  2012年   16569篇
  2011年   17817篇
  2010年   14206篇
  2009年   13590篇
  2008年   13440篇
  2007年   13234篇
  2006年   11769篇
  2005年   9876篇
  2004年   8403篇
  2003年   7277篇
  2002年   6155篇
  2001年   5381篇
  2000年   4441篇
  1999年   3684篇
  1998年   3175篇
  1997年   2811篇
  1996年   2533篇
  1995年   2623篇
  1994年   2406篇
  1993年   1985篇
  1992年   1898篇
  1991年   1639篇
  1990年   1322篇
  1989年   1145篇
  1988年   1056篇
  1987年   946篇
  1986年   834篇
  1985年   1022篇
  1984年   840篇
  1983年   511篇
  1982年   600篇
  1981年   529篇
  1980年   391篇
  1979年   322篇
  1978年   246篇
  1977年   218篇
  1976年   186篇
  1975年   73篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
《Vaccine》2022,40(15):2274-2281
We evaluated compliance to the ACIP pneumococcal vaccination recommendations issued in 2014 for adults aged ≥ 65 years and in 2012 for adults with high-risk (HR) conditions. The MarketScan® Commercial and Medicare Supplemental databases (January 2007-June 2019) were used to identify the cohorts of interest. Analyses for adults aged ≥ 65 years were adjusted to account for missing vaccination history. Two HR cohorts were identified. The HR1 cohort included patients with immunocompromising conditions, functional or anatomic asplenia, cerebrospinal fluid leak, or cochlear implant. The HR2 cohort included patients with chronic heart, lung, or liver disease; diabetes mellitus; alcoholism; cirrhosis; or cigarette smoking. Full compliance for those aged ≥ 65 years or in the HR1 cohort was defined as receipt of PCV13 and PPSV23, and partial compliance was defined as receipt of PCV13 or PPSV23. For those in the HR2 cohort, full compliance was defined as receipt of PPSV23. Annual compliance rates were estimated using the Kaplan–Meier method.Among those aged ≥ 65 years, partial compliance at 4 years post index was 53% and full compliance was 17% in adjusted analyses. In subjects ≥ 65 years receiving the first vaccination, 42% received the second vaccination by year 4. For the HR1 cohort, partial compliance was 19% and full compliance was 5% at 6 years post index date. For the HR2 cohort, full compliance was 20% at 6 years, with the highest rate in patients with diabetes (27%) and the lowest rate in patients with alcoholism (8%).Additional efforts are needed to maximize compliance to the ACIP pneumococcal vaccine recommendations among adults ≥ 65 years of age and adults with HR conditions including streamlined recommendations and single-dose vaccines. These efforts may subsequently reduce the incidence and burden of pneumococcal disease.  相似文献   
72.
社区动脉粥样硬化风险(ARIC)研究是1987年由美国心、肺和血液研究所资助的关注非洲裔美国人心血管健康的最大研究。旨在调查心脏病的危险因素以及心血管疾病与认知之间的联系。ARIC研究的许多发现加深了对动脉粥样硬化性心血管病病因的了解,在心血管病预防领域做出了重大贡献,证明了以人群为基础的研究对改善健康和预防疾病的重要性。主要概述ARIC研究的起源、目的、研究设计、对心血管医学的贡献以及未来的发展方向。  相似文献   
73.
目的 慢性牙周炎表现的病理性骨吸收非常常见,牙周膜干细胞(PDLSCs)的外泌体(Exo)对骨吸收的作用和影响尚不明确,本研究分析了该Exo蛋白组分对破骨细胞分化的影响。方法 分别从正畸前拔牙患者和慢性牙周炎患者的牙周膜组织中提取PDLSCs,通过流式细胞术检测表面标记物;通过差速离心分别提取2种细胞的Exo,即Exo-WT和Exo-CP,并通过Western blot、透射电子显微镜(TEM)、蛋白浓度检测、纳米粒径追踪检测Exo特征;通过蛋白质谱检测2种Exo的蛋白组分;通过酶联免疫吸附(ELISA)验证了差异表达蛋白肿瘤坏死因子α(TNF-α)、核因子κB受体活化因子配体(RANKL)、白细胞介素(IL)-1α、转化生长因子β(TGF-β)、骨形态发生蛋白2(BMP-2)表达水平;将10、100、1 000 μg·mL-1的Exo-CP或Exo-WT加入RAW264.7培养基中并于5 d时通过实时荧光定量聚合酶链反应(RT-qPCR)、Western blot、抗酒石酸酸性磷酸酶(TRAP)染色检测破骨分化相关指标表达情况;采用SPSS 24.0软件对实验数据进行统计学分析。结果 Exo-CP富集的差异表达蛋白主要与破骨细胞分化的TNF信号通路、核转录因子κB(NF-κB)信号通路相关;ELISA实验证实了Exo-CP中高表达TNF-α、RANKL、IL-1α,低表达TGF-β1、BMP-2(P<0.05);Exo-CP作用于RAW264.7,显著提高了细胞的破骨分化相关基因及蛋白的表达水平,TRAP染色可见分化的破骨细胞,且呈现浓度依赖性,100、1 000 μg·mL-1浓度Exo-CP对破骨细胞分化的促进作用显著高于10 μg·mL-1浓度组(P<0.05)。结论 慢性牙周炎的病理性骨吸收可能由炎性PDLSCs所分泌的Exo通过促进破骨细胞分化引起,Exo中主要的作用蛋白可能为RANKL和TNF-α,本研究为慢性牙周炎骨吸收的发病机制提供了新视角。  相似文献   
74.
PurposeAcquired hemophilia (AH) is a rare, serious bleeding disorder most often associated with older age and life-threatening complications. The patient care pathway for AH is complex because of the different types of bleeding, the presence of comorbidities, and the heterogeneity of medical specialists who care for these patients.MethodsThis observational study used the French national PMSI (Programme de médicalisation des systèmes d’information) database to characterize patients with AH in real-life practice and analyze their hospital pathway. In total, 180 patients with AH were identified over a 5-year study period (January 2010 to December 2014), based on three criteria: bypassing agent use, International Classification of Diseases, 10th revision code allocation, and aged over 65 years. Comparison of the incidence rate of AH versus registry data validated the PMSI as an epidemiological database.ResultsRituximab was prescribed more often (60/180; 33.3%) than expected following guidelines and was associated in half of cases to early infections (32/60; 53.3%), surgery procedures were frequently performed during the year before AH onset (29/159; 18.2%), which may suggest a triggering effect, extended hospital stays (median: 20 days) and mortality remaining high (66/180; 36.7%) that occurred mainly during the first month after AH diagnosis. Median costs and number of injections were comparable between recombinant activated factor VII and plasma-derived activated prothrombin complex concentrate.ConclusionThese findings could inform future medico-economic approaches in this AH population (duration of stays, bypassing agents, rituximab use, comorbidities, hospitalizations with infections).  相似文献   
75.
76.
赵帆  王君 《中国校医》2022,36(1):12
目的 探讨基于记忆-遗忘规律的健康教育在改善冠心病患者健康促进生活方式和自我健康管理行为中的影响。方法 选择住院治疗的冠心病患者160例,采用随机数字表法分为观察组(80例)和对照组(80例)。对照组接受常规住院健康教育,观察组接受基于记忆-遗忘曲线规律制定的针对性的健康教育干预。在干预前、干预后使用健康促进生活方式评定量表和冠心病自我管理行为量表,测量两组患者的健康促进生活方式和自我管理行为水平。结果 干预前,两组患者健康促进生活方式和自我健康管理行为水平比较,差异无统计学意义(t=-1.72, 1.88,P值均>0.05)。干预后,观察组健康促进生活方式总分为(83.58±9.54),高于干预前的(63.08±7.11),(t=11.11, P<0.001)。干预前,2组自我管理行为得分比较,差异无统计学意义(t=1.88, P>0.05);干预后,观察组自我管理行为总得分为(118.44±8.42),高于对照组的(99.86±6.49),(t=-15.63, P<0.001)。结论 基于记忆-遗忘规律的健康教育,对冠心病患者健康促进生活方式和自我管理行为有明显改善和提高。  相似文献   
77.
78.
目的 运用标准化患者法评估四川农村地区基层医生不稳定型心绞痛和2型糖尿病两种慢性病诊断准确性现状,探讨基层医生两种慢性病诊断准确性的主要影响因素,为提升基层医生两种慢性病诊断准确性提供科学依据。方法 采用多阶段随机整群抽样方法,抽取四川省自贡市5个区/县50个乡镇100个村为研究现场,以调查当日在岗的全科及内科医生作为研究对象。共进行两轮数据采集,第1轮采集样本乡镇卫生院和村卫生室医生的基本信息;第1轮调查完成1个月后,运用标准化患者法开展第2轮调查,收集农村基层医生对不稳定型心绞痛和2型糖尿病诊断结果信息。运用Logistic回归分析农村基层医生不稳定型心绞痛和2型糖尿病诊断准确性的影响因素。结果 共纳入172名农村基层医生,完成186次标准化患者访问,正确诊断率为48.39%。其中不稳定型心绞痛的正确诊断率为18.68%(17/91),2型糖尿病的正确诊断率为76.84%(73/95)。Logistic回归分析显示,具有执业医师资质的农村基层医生更有可能做出正确诊断(OR=4.857,95%CI=1.076~21.933,P=0.040)。农村基层医生在诊断过程中涉及的必要问诊和检查条目越多,做出正确诊断的概率越高(OR=1.627,95%CI=1.065~2.485,P=0.024)。与不稳定型心绞痛相比,农村基层医生对2型糖尿病做出正确诊断的可能性更高(OR=6.306,95%CI=3.611~11.013,P<0.001)。结论 四川农村基层医生不稳定型心绞痛和2型糖尿病诊断准确性整体较差,建议以基层医生慢性病诊断过程质量改善为突破口,提升基层医生执业水平,进而提高慢性病诊断准确性。  相似文献   
79.
PurposeA risk of percutaneous transthoracic needle biopsy (PTNB) is hemoptysis, which can range from mild to life-threatening. The reported occurrence of hemoptysis is 1.7% to 14.5%, and the demographic, patient, and procedure characteristics have not been extensively described. The purpose of this study was to assess the associations of demographic, patient, and procedure characteristics with the severity of hemoptysis.Materials and MethodsA single institution, single group, retrospective, electronic medical record (EMR) review was performed on all hemoptysis events occurring between 2008 and 2018. Demographic, clinical, and procedure variables were extracted from EMRs. Outcome of hemoptysis events was graded using Common Terminology Criteria for Adverse Events (CTCAE). Mild-moderate and severe hemoptysis were defined as CTCAE classifications of 1-2 and 3-5, respectively. Associations were generated using logistic regressions and Likelihood Ratio Chi-Square tests.ResultsIn 10 years, 14,665 PTNB resulted in 231 hemoptysis events occurring in 229 patients; 12.7% (n = 29) of those were severe. The strongest and statistically significant variables associated with an increased likelihood of a severe event, if an event occurred, were cigarette pack years (OR = 1.02, 95% C.I. = 1.01-1.04, p = .020); history of chronic obstructive pulmonary disease (COPD) (OR = 3.68, 95% C.I. = 1.53-8.82, p = .003); core biopsy technique (OR = 8.13, 95% CI = 1.07, 61.40, p = .042), and larger diameter needle (20 g vs. 18 g: OR = 2.60, 95% CI 1.09, 6.17, p = .031).ConclusionsPTNB-associated hemoptysis was an uncommon event that was rarely life-threatening. The extent of the patient’s smoking history, the diagnosis of COPD, and core biopsy technique were associated with an increased likelihood of severe hemoptysis.  相似文献   
80.
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