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   11755篇
  免费   1022篇
  国内免费   260篇
耳鼻咽喉   189篇
儿科学   221篇
妇产科学   91篇
基础医学   732篇
口腔科学   482篇
临床医学   1769篇
内科学   1401篇
皮肤病学   85篇
神经病学   587篇
特种医学   372篇
外科学   653篇
综合类   1554篇
现状与发展   1篇
预防医学   2714篇
眼科学   68篇
药学   1483篇
  29篇
中国医学   356篇
肿瘤学   250篇
  2023年   166篇
  2022年   251篇
  2021年   486篇
  2020年   450篇
  2019年   370篇
  2018年   377篇
  2017年   409篇
  2016年   419篇
  2015年   408篇
  2014年   775篇
  2013年   875篇
  2012年   733篇
  2011年   754篇
  2010年   584篇
  2009年   585篇
  2008年   532篇
  2007年   548篇
  2006年   469篇
  2005年   413篇
  2004年   332篇
  2003年   304篇
  2002年   246篇
  2001年   229篇
  2000年   186篇
  1999年   175篇
  1998年   177篇
  1997年   155篇
  1996年   136篇
  1995年   174篇
  1994年   127篇
  1993年   107篇
  1992年   113篇
  1991年   76篇
  1990年   81篇
  1989年   83篇
  1988年   77篇
  1987年   56篇
  1986年   69篇
  1985年   71篇
  1984年   69篇
  1983年   52篇
  1982年   72篇
  1981年   51篇
  1980年   45篇
  1979年   43篇
  1978年   29篇
  1977年   21篇
  1976年   20篇
  1975年   11篇
  1974年   11篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
1.
ObjectiveThe use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation.MethodsThe AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement.ResultsThe expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively.ConclusionsAchieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.  相似文献   
2.
目的 探究影响我国老年人认知水平的变化趋势,分离出年龄、队列效应。方法 基于CLHLS(2002—2018)多重队列追踪数据,以Stata16.0软件为工具,运用分层生长曲线模型进行统计分析。结果 本研究发现,个体行为生活方式、社会经济地位、性别、慢性病数量对认知水平均具有统计学意义;年龄、队列对认知水平的变化具有独立效应;随着年龄的增长,我国老年人认知水平下降,认知水平的城乡、性别差异明显;较年轻出生队列的老年人认知水平较好,认知水平的城乡差异随着队列的年轻化而变大,性别差异在较年轻队列有略微缩小的趋势。结论 影响认知水平因素复杂,认知障碍会增加医疗成本及照护负担,因此需准确把握老年认知水平的变化规律与作用路径,从而为卫生服务、养老保障、长期医疗照护的资源配置提供科学依据。  相似文献   
3.
【目的】 在“中国科技期刊卓越行动计划”实施三周年之际,有必要对我国科技期刊2035年迈入“世界第一方阵”目标的具体任务进行重新审视和预判,以进一步明确发展方向,动态调整推进思路。【方法】 采用国内外科技期刊、科技论文、科技期刊评价成果的系统性发展数据对科技期刊“世界第一方阵” 国家(或地区)在高水平科技期刊数量与质量层面的入围标准进行界定,在深入总结现有基础和优势的同时,对我国科技期刊综合实力与“世界第一方阵”国家(或地区)的现实差距进行逐一梳理和剖析,并对实现目标的可行性和推进思路进行研判和设计。【结果】 必须继续加强高水平英文科技期刊创办和培育力度、持续加大优秀中文科技期刊的建设强度、快速推进国内外科技期刊论文等质同效评价制度的建设与引导,并积极探索建立科学家和科研机构办好一流科技期刊的责任制度和贡献激励机制、创新发展编辑人才队伍培养与激励管理思路、深入实践灵活多样的期刊出版市场资本运作模式、稳步推进期刊出版市场机制和管理制度改革,为我国科技期刊事业的高质量发展提速增效。【结论】 虽然当前阶段目标任务艰巨,但迈入“世界第一方阵”未来可期。  相似文献   
4.
5.
6.
ObjectiveTo evaluate the effect of receiving information about the benefits and harms of breast cancer screening in informed choice, according to educational level.MethodSecondary analysis of a randomized, controlled study, in four screening programs, in Catalonia and the Canary Islands (Spain). We analyzed 400 women who were going to be invited to participate for the first time. The intervention group received a decision aid that showed the benefits and harms of screening. The control group received a standard brochure that recommended participating in the screening program. Educational level was grouped into two categories, low and high. The primary outcome was informed choice defined as adequate knowledge and consistency between attitudes and intentions.ResultsThe intervention produced a greater increase in knowledge in women with a high educational level compared to those with a lower educational level. Among women who received the intervention, informed choice was almost three times higher in those with a high educational level (27% versus 11%). No differences were observed between educational levels in decisional conflict, confidence in the decision, anxiety and worry about breast cancer, in the intervention and control groups.ConclusionsA decision aid for breast cancer screening had much more impact on informed choice among women with a high educational level. In women with low educational level, the attitude towards screening improved and there was an increase in the intention to be screened.  相似文献   
7.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  相似文献   
8.
《Vaccine》2021,39(14):1933-1942
The genetic and antigenic drift associated with the high pathogenicity avian influenza (HPAI) viruses of Goose/Guangdong (Gs/GD) lineage and the emergence of vaccine-resistant field viruses underscores the need for a broadly protective H5 influenza A vaccine. Here, we tested experimental vector herpesvirus of turkey (vHVT)-H5 vaccines containing either wild-type clade 2.3.4.4A-derived H5 inserts or computationally optimized broadly reactive antigen (COBRA) inserts with challenge by homologous and genetically divergent H5 HPAI Gs/GD lineage viruses in chickens. Direct assessment of protection was confirmed for all the tested constructs, which provided clinical protection against the homologous and heterologous H5 HPAI Gs/GD challenge viruses and significantly decreased oropharyngeal shedding titers compared to the sham vaccine. The cross reactivity was assessed by hemagglutinin inhibition (HI) and focus reduction assay against a panel of phylogenetically and antigenically diverse H5 strains. The COBRA-derived H5 inserts elicited antibody responses against antigenically diverse strains, while the wild-type-derived H5 vaccines elicited protection mostly against close antigenically related clades 2.3.4.4A and 2.3.4.4D viruses. In conclusion, the HVT vector, a widely used replicating vaccine platform in poultry, with H5 insert provides clinical protection and significant reduction of viral shedding against homologous and heterologous challenge. In addition, the COBRA-derived inserts have the potential to be used against antigenically distinct co-circulating viruses and future drift variants.  相似文献   
9.
目的探讨恐惧疾病进展在肺癌患者配偶希望水平与生活质量间的中介作用。方法采取方便抽样法,选取2019年11月—2021年1月新疆某三级甲等肿瘤专科医院165例肺癌患者配偶作为研究对象,采用Herth希望指数量表(Herth Hope Index,HHI)、癌症患者恐惧疾病进展简化量表(Fear ofProgression Questionnaire-Short Form,FoP-Q-SF)、生活质量核心量表(European Organization for Research and Treatment of Cancer Quality of Life Questionnaire,QLQ-C30)进行问卷调查,运用Pearson相关性分析肺癌患者配偶恐惧疾病进展、希望水平、生活质量之间的相关性;采用AMOS23.0软件建立结构方程模型,并用偏差校正的非参数百分位Bootstrap程序对模型进行检验。结果共有162例肺癌患者配偶完成研究,HHI总分为(26.28±2.90)分,FoP-Q-SF总分为(43.74±4.68)分,QLQ-C30总分为(55.29±14.26)分。相关分析显示,肺癌患者配偶生活质量与希望水平呈正相关(r=0.541,P<0.001)与恐惧疾病进展呈负相关(r=-0.469,P<0.001);希望水平与恐惧疾病进展呈负相关(r=-0.574,P<0.001)。希望水平对生活质量有显著正向效应(β=0.428,P<0.001),并通过恐惧疾病进展的部分中介作用间接影响其生活质量,中介效应占总效应的33.12%。结论希望水平对肺癌患者配偶生活质量有直接预测作用,恐惧疾病进展在希望水平与生活质量之间起到部分中介作用。  相似文献   
10.
《Neuro-Chirurgie》2023,69(3):101428
BackgroundRodent models are commonly used experimentally to assess treatment effectiveness in spinal fusion. Certain factors are associated with better fusion rates. The objectives of the present study were to report the protocols most frequently used, to evaluate factors known to positively influence fusion rate, and to identify new factors.MethodA systematic literature search of PubMed and Web of Science found 139 experimental studies of posterolateral lumbar spinal fusion in rodent models. Data for level and location of fusion, animal strain, sex, weight and age, graft, decortication, fusion assessment and fusion and mortality rates were collected and analyzed.ResultsThe standard murine model for spinal fusion was male Sprague Dawley rats of 295 g weight and 13 weeks’ age, using decortication, with L4-L5 as fusion level. The last two criteria were associated with significantly better fusion rates. On manual palpation, the overall mean fusion rate in rats was 58% and the autograft mean fusion rate was 61%. Most studies evaluated fusion as a binary on manual palpation, and only a few used CT and histology. Average mortality was 3.03% in rats and 1.56% in mice.ConclusionsThese results suggest using a rat model, younger than 10 weeks and weighing more than 300 grams on the day of surgery, to optimize fusion rates, with decortication before grafting and fusing the L4-L5 level.  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