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   15594篇
  免费   865篇
  国内免费   206篇
耳鼻咽喉   136篇
儿科学   251篇
妇产科学   205篇
基础医学   1721篇
口腔科学   166篇
临床医学   2197篇
内科学   1352篇
皮肤病学   98篇
神经病学   3178篇
特种医学   714篇
外科学   1355篇
综合类   1679篇
一般理论   5篇
预防医学   1039篇
眼科学   105篇
药学   1095篇
  16篇
中国医学   184篇
肿瘤学   1169篇
  2023年   174篇
  2022年   375篇
  2021年   557篇
  2020年   528篇
  2019年   437篇
  2018年   526篇
  2017年   490篇
  2016年   459篇
  2015年   460篇
  2014年   1006篇
  2013年   1182篇
  2012年   726篇
  2011年   915篇
  2010年   701篇
  2009年   826篇
  2008年   843篇
  2007年   721篇
  2006年   718篇
  2005年   535篇
  2004年   466篇
  2003年   425篇
  2002年   292篇
  2001年   312篇
  2000年   256篇
  1999年   260篇
  1998年   209篇
  1997年   218篇
  1996年   211篇
  1995年   175篇
  1994年   158篇
  1993年   124篇
  1992年   141篇
  1991年   115篇
  1990年   106篇
  1989年   80篇
  1988年   94篇
  1987年   79篇
  1986年   69篇
  1985年   98篇
  1984年   97篇
  1983年   63篇
  1982年   79篇
  1981年   47篇
  1980年   52篇
  1979年   50篇
  1978年   38篇
  1977年   37篇
  1976年   37篇
  1973年   18篇
  1972年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Vaccine》2022,40(23):3236-3243
BackgroundInfections can have a significant impact on morbidity and mortality in multiple sclerosis (MS) patients. Therefore, vaccinations are of immense importance. If vaccination willingness is to be increased, possible influencing factors should be identified. The aim of the present study was to investigate the status of active immunisation in MS patients in association with sociodemographic, clinical-neurological, psychopathological and personality variables using the NEO-Five Factor Inventory, the Temperament and Character Inventory-Revised and the Hospital Anxiety and Depression Scale.MethodFour hundred and four MS patients from two German neurological hospitals were examined for their vaccination attitudes, in detail, the general willingness to vaccinate and the current vaccination status of mumps, measles and rubella (MMR) as well as tetanus and influenza. We also looked at the current level of disability in relation to the current vaccination status, as well as possible associated personality and psychopathological variables.ResultsPatients with a complete MMR vaccination status were significantly younger and those with a complete influenza vaccination status were significantly older than those with related incomplete vaccination status. Tetanus vaccination status completeness did not differ depending on age and did not show substantial association with personality scores. However, influenza vaccination completeness was associated with differences in personality and psychopathological variables; extraversion, openness, novelty seeking, harm avoidance and anxiety. A reported general vaccination willingness was significantly correlated with the current completeness of tetanus and influenza vaccinations. Novelty seeking, persistence, extraversion, agreeableness, conscientiousness and neuroticism were found associated with an increased vaccination willingness. Anxiety and depression were not related to general vaccination willingness.ConclusionsNo specific personality trait could be defined on its own in relation to general vaccination willingness or complete vaccination status. Younger patients should be made more aware of influenza vaccination. Reasons for rather low vaccination rates need to be further investigated.  相似文献   
2.
BackgroundOne in two people with multiple sclerosis (PwMS) will fall in a three-month period. Predicting which patients will fall remains a challenge for clinicians. Standardized functional assessments provide insight into balance deficits and fall risk but their use has been limited to supervised visits.Research questionThe study aim was to characterize unsupervised 30-second chair stand test (30CST) performance using accelerometer-derived metrics and assess its ability to classify fall status in PwMS compared to supervised 30CST.MethodsThirty-seven PwMS (21 fallers) performed instrumented supervised and unsupervised 30CSTs with a single wearable sensor on the thigh. In unsupervised conditions, participants performed bi-hourly 30CSTs and rated their balance confidence and fatigue over 48-hours. ROC analysis was used to classify fall status for 30CST performance.ResultsNon-fallers (p = 0.02) but not fallers (p = 0.23) differed in their average unsupervised 30CST performance (repetitions) compared to their supervised performance. The unsupervised maximum number of 30CST repetitions performed optimized ROC classification AUC (0.79), accuracy (78.4%) and specificity (90.0%) for fall status with an optimal cutoff of 17 repetitions.SignificanceBrief durations of instrumented unsupervised monitoring as an adjunct to routine clinical assessments could improve the ability for predicting fall risk and fluctuations in functional mobility in PwMS.  相似文献   
3.
4.
5.
《Vaccine》2022,40(30):4038-4045
PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.ResultsAmong 110 participants, 56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed.ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.  相似文献   
6.
Introduction: Dysregulation of histone deacetylase (HDAC) activity is an epigenetic hallmark of multiple myeloma (MM), leading to aberrant gene expression and cellular signaling in myeloma cell growth, survival and resistance to therapy. Hyper-methylation at diagnosis is a frequent observation, which eventually may convert to hypo-methylation during advanced phases.

Areas covered: A literature search on ‘HDAC inhibitors’ and ‘multiple myeloma’ was carried out using PubMed and Google Scholar in the preparation of this overview on clinical efficacy and safety data.

Expert opinion: First-generation non-selective HDAC inhibitors have demonstrated minimal single-agent activity in refractory MM. Subsequently, combination therapy has proven an improvement in progression-free survival (PFS) but not response rates. The main concerns are associated with toxicities. Ongoing studies on new and more selective agents, i.e. Romidepsin or Ricolinostat, are promising in terms of better efficacy and less toxicity.  相似文献   

7.
目的探究肿瘤坏死因子-α(Tumornecrosis factor-α,TNF-α)-308基因对导管相关性脓毒症(Catheter related sepsis,CRS)患者病情的影响,旨在为临床治疗CRS提供科学依据。方法选取2017年7月-2018年10月于浙江大学医学院附属杭州市第一人民医院接受治疗的86例CRS患者为研究对象,按照是否并发多器官功能障碍综合征将患者分为试验组和对照组,对照组共48例,未并发多器官功能障碍综合征,试验组共38例,并发多器官功能障碍综合征,分析两组患者TNF-α-308基因多态性差异,使用多因素Logistic回归分析CRS患者并发多器官功能障碍综合征的危险因素。结果试验组GA基因型频率34.21%、AA基因型频率50.00%、高G等位基因频率18.42%均高于对照组,GG基因型频率52.63%、A等位基因频率28.95%均低于对照组,差异均具有统计学意义(P<0.05);多因素Logistic回归分析结果显示,低GG基因型频率、低G等位基因频率、高GA基因型频率、高AA基因型频率、高A等位基因频率是CRS患者并发多器官功能障碍综合征的危险因素(P<0.05)。结论TNF-α-308基因与CRS患者病情密切相关,GG基因型频率和G等位基因频率降低,GA基因型频率、AA基因型频率、A等位基因频率升高会加重患者的病情,增加多器官功能障碍综合征的发生风险,临床上应该加以重视。  相似文献   
8.
9.
Ceramide synthases (CerS) synthesise ceramides of defined acyl chain lengths, which are thought to mediate cellular processes in a chain length-dependent manner. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed a significant elevation of CerS2 and its products, C24-ceramides, in CD11b+ cells (monocytes and neutrophils) isolated from blood. This result correlates with the clinical finding that CerS2 mRNA expression and C24-ceramide levels were significantly increased by 2.2- and 1.5-fold, respectively, in white blood cells of MS patients. The increased CerS2 mRNA/C24-ceramide expression in neutrophils/monocytes seems to mediate pro-inflammatory effects, since a specific genetic deletion of CerS2 in blood cells or a total genetic deletion of CerS2 significantly delayed the onset of clinical symptoms, due to a reduced infiltration of immune cells, in particular neutrophils, into the central nervous system. CXCR2 chemokine receptors, expressed on neutrophils, promote the migration of neutrophils into the central nervous system, which is a prerequisite for the recruitment of further immune cells and the inflammatory process that leads to the development of MS. Interestingly, neutrophils isolated from CerS2 null EAE mice, as opposed to WT EAE mice, were characterised by significantly lower CXCR2 receptor mRNA expression resulting in their reduced migratory capacity towards CXCL2. Most importantly, G-CSF-induced CXCR2 expression was significantly reduced in CerS2 null neutrophils and their migratory capacity was significantly impaired. In conclusion, our data strongly indicate that G-CSF-induced CXCR2 expression is regulated in a CerS2-dependent manner and that CerS2 thereby promotes the migration of neutrophils, thus, contributing to inflammation and the development of EAE and MS.  相似文献   
10.
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