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   14104篇
  免费   723篇
  国内免费   191篇
耳鼻咽喉   85篇
儿科学   234篇
妇产科学   237篇
基础医学   1710篇
口腔科学   118篇
临床医学   1813篇
内科学   1215篇
皮肤病学   95篇
神经病学   3721篇
特种医学   152篇
外科学   637篇
综合类   1614篇
一般理论   1篇
预防医学   878篇
眼科学   152篇
药学   1612篇
  3篇
中国医学   574篇
肿瘤学   167篇
  2024年   23篇
  2023年   294篇
  2022年   470篇
  2021年   686篇
  2020年   606篇
  2019年   413篇
  2018年   375篇
  2017年   469篇
  2016年   467篇
  2015年   432篇
  2014年   952篇
  2013年   1127篇
  2012年   956篇
  2011年   1155篇
  2010年   880篇
  2009年   808篇
  2008年   813篇
  2007年   673篇
  2006年   560篇
  2005年   416篇
  2004年   341篇
  2003年   324篇
  2002年   232篇
  2001年   221篇
  2000年   153篇
  1999年   122篇
  1998年   115篇
  1997年   93篇
  1996年   90篇
  1995年   86篇
  1994年   74篇
  1993年   55篇
  1992年   58篇
  1991年   49篇
  1990年   50篇
  1989年   44篇
  1988年   31篇
  1987年   36篇
  1986年   20篇
  1985年   50篇
  1984年   34篇
  1983年   14篇
  1982年   21篇
  1981年   22篇
  1980年   12篇
  1979年   19篇
  1978年   14篇
  1977年   11篇
  1974年   10篇
  1970年   8篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
《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   
3.
目的 观察结肠癌HCT116细胞健脾消癌方的条件培养液对HUVEC细胞管腔形成的影响,从PI3K/Akt生物轴调控角度探讨其作用机制。方法 培养HCT116细胞,细胞设3组:对照组,健脾消癌方组(加入15%健脾消癌方含药血清)及人参皂苷Rg3组;制备HCT116细胞健脾消癌方条件培养液(分组及制备方法见实验方法),用条件培养液干预HUVEC(脐静脉内皮细胞,Human Umbilical Vein Endothelial Cells),Matrigel基质胶法检测HCT116细胞健脾消癌方条件培养液对HUVEC小管形成的影响。随后采用蛋白免疫印迹法(Western blot)检测各组HCT116细胞磷脂酰肌醇3-激酶(PI3K)、蛋白激酶B(Akt)、p-Akt、VEGF(血管内皮生长因子,Vascular endothelial growth factor)蛋白表达。最后在结肠癌HCT116荷瘤小鼠中验证健脾消癌方对肿瘤生长速度的影响,并经瘤组织VEGF蛋白表达、CD31免疫组化染色检测肿瘤内血管生成情况。结果 模型组HUVEC细胞管腔形成较空白血清组显著增加(P<0.05);健脾消癌方组及人参皂苷Rg3组较模型组HUVEC细胞管腔形成显著减少(P<0.01)。p-Akt和VEGF蛋白表达水平模型组高于空白血清组(P<0.05),健脾消癌方组及人参皂苷Rg3组显著低于模型组(P<0.01);PI3K、Akt蛋白表达量组间差异无统计学意义。与对照组比较,模型组荷瘤小鼠肿瘤体积显著性增大,瘤组织内VEGF表达、CD31阳性面积显著性增加,差异有统计学意义(P<0.05);与模型组比较,健脾消癌方组及人参皂苷Rg3组荷瘤小鼠肿瘤体积显著减小,瘤组织内VEGF表达、CD31阳性面积降低,差异有统计学意义(P<0.05)。结论 健脾消癌方可抑制肿瘤的血管生成和生长,其作用机制可能与PI3K/Akt生物轴调控VEGF表达有关。  相似文献   
4.
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   
5.
6.
BackgroundThe estimated number of people living with anxiety disorders worldwide is around 264 million and is estimated to have worsened with the recent pandemic of COVID-19. Acupuncture has shown to have excellent therapeutic effects in reducing anxiety.DesignDouble-blinded randomized controlled clinical trial with 56 participants (21–82 years) with anxiety diagnosed by 3 different anxiety scales (BAI, GAD-7 and OASIS). A 30-min acupuncture session was applied once a week for 10 weeks.AimsEvaluate the effectiveness of acupuncture and electroacupuncture in the treatment of anxiety to verify if: (1) People with high anxiety report reduced scores after 5 and 10 sessions; (2) Salivary cortisol levels accompanied the reduced scores; (3) Electroacupuncture treatment is more effective than acupuncture; (4) the treatments is independent of anxiolytic medication.MethodsVolunteers were randomized into 3 groups (control, acupuncture, and electroacupuncture). The results were analyzed by anxiety scales and salivary cortisol tests.ResultsThe findings show an improvement in anxiety, assessed by BAI, GAD-7 and OASIS, after the 5th session of acupuncture (p < 0.05) and electroacupuncture (p < 0.05) and the 10th session for both techniques (p < 0.001). The salivary cortisol values measured in the morning followed this pattern (p < 0.05), although the reduction of the night cortisol values was not statistically significant. Electroacupuncture and acupuncture show similar efficacy. The positive effect after the treatments is independent of anxiolytic medication (p < 0.001).ConclusionAcupuncture and electroacupuncture are effective in treating anxiety on their own or as adjuncts to pharmacological therapy.Trial registration numberNºP445-08/2017 (Unidade de Investigação em Ciências da Saúde);  相似文献   
7.
BackgroundShift work may cause insomnia and sleepiness in individuals. The present study aimed to exam shift work disorder (SWD), and to investigate their associations with individual characteristics.MethodsA total of 1833 shift workers were assessed using the Pittsburg Sleep Quality Index, Epworth Sleepiness Scale (ESS), Composite Scale of Morningness (CSM), Circadian Type Inventory (CTI), Center for Epidemiologic Studies–Depression Scale (CES-D), Beck Anxiety Inventory (BAI) and other self-compiled socio-demographic questionnaires.ResultsIn the current sample, 17.1% shift workers have experienced insomnia symptoms, 20.9% were tested for daytime sleepiness, and 19.9% were categorized as having SWD. Logistics regressions revealed that history of mental disorders (OR = 2.04, 95% CI = 1.30–3.21), chronic physical illness (OR = 1.53, 95% CI = 1.17–1.99), CES-D scores (OR = 1.03, 95% CI = 1.02–1.05), BAI scores (OR = 1.04, 95% CI = 1.03–1.06), languid/vigorous tendencies (OR = 1.06, 95% CI = 1.03–1.10) were positively associated with the onset of SWD, while morningness (OR = 0.97, 95% CI = 0.94–0.99) decreased the odds of SWD onset.ConclusionsThese findings suggested that attention should be drawn to individuals with mental and chronic diseases in when scheduling work shifts. While SWD and its associates should be considered when providing psychological services to shift workers.  相似文献   
8.
Major depressive disorder (MDD) is a disabling and highly prevalent mood disorder as well as a common cause of suicide. Chronic stress, inflammation, and intestinal dysbiosis have all been shown to play crucial roles in the pathophysiology of MDD. Although conventional antidepressants are widely used in the clinic, they can take weeks to months to produce therapeutic effects. The discovery that ketamine promotes fast and sustaining antidepressant responses is one of the most important breakthroughs in the pharmacotherapy of MDD. However, the adverse psychomimetic/dissociative and neurotoxic effects of ketamine discourage its chronic use. Therefore, agmatine, an endogenous glutamatergic modulator, has been postulated to elicit fast behavioral and synaptogenic effects by stimulating the mechanistic target of rapamycin complex 1 signaling pathway, similar to ketamine. However, recent evidence has demonstrated that the modulation of the NLR family pyrin domain containing 3 inflammasome and gut microbiota, which have been shown to play a crucial role in the pathophysiology of MDD, may also participate in the antidepressant-like effects of both ketamine and agmatine. This review seeks to provide evidence about the mechanisms that may underlie the fast antidepressant-like responses of agmatine in preclinical studies. Considering the anti-inflammatory properties of agmatine, it may also be further investigated as a useful compound for the management of MDD associated with a pro-inflammatory state. Moreover, the fast antidepressant-like response of agmatine noted in animal models should be investigated in clinical studies.  相似文献   
9.
In December 2019 a novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), started spreading from Wuhan city of Chinese Hubei province and rapidly became a global pandemic. Clinical symptoms of the disease range from paucisymptomatic disease to a much more severe disease. Typical symptoms of the initial phase include fever and cough, with possible progression to acute respiratory distress syndrome. Gastrointestinal manifestations such as diarrhoea, vomiting and abdominal pain are reported in a considerable number of affected individuals and may be due to the SARS-CoV-2 tropism for the peptidase angiotensin receptor 2. The intestinal homeostasis and microenvironment appear to play a major role in the pathogenesis of COVID-19 and in the enhancement of the systemic inflammatory responses. Long-term consequences of COVID-19 include respiratory disturbances and other disabling manifestations, such as fatigue and psychological impairment. To date, there is a paucity of data on the gastrointestinal sequelae of SARS-CoV-2 infection. Since COVID-19 can directly or indirectly affect the gut physiology in different ways, it is plausible that functional bowel diseases may occur after the recovery because of potential pathophysiological alterations (dysbiosis, disruption of the intestinal barrier, mucosal microinflammation, post-infectious states, immune dysregulation and psychological stress). In this review we speculate that COVID-19 can trigger irritable bowel syndrome and we discuss the potential mechanisms.  相似文献   
10.
The novel coronavirus disease (COVID-19), first detected in December of 2019 and declared a global pandemic in March of 2020, continues to pose a serious threat to public health and safety worldwide. Many individuals report anxiety in response to this threat, and at high levels, such anxiety can result in adverse mental health outcomes and maladaptive behavioral responses that have consequences for the health of communities more broadly. Predictors of excessive anxiety in response to COVID-19 are understudied. Accordingly, the present study examined psychological factors that predict more intense COVID-19-related anxiety. 438 community members completed measures assessing COVID-19-related anxiety as well as psychological variables hypothesized to predict anxious responding to the threat of COVID-19. As expected, obsessive-compulsive symptoms related to contamination, the fear of arousal-related body sensations (i.e., anxiety sensitivity), and body vigilance each predicted more severe anxiety related to the pandemic. Obsessive-compulsive symptoms related to responsibility for causing harm also emerged as a predictor. Study limitations and implications are discussed.  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