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   431篇
  免费   23篇
儿科学   4篇
妇产科学   3篇
基础医学   55篇
临床医学   61篇
内科学   88篇
皮肤病学   2篇
神经病学   56篇
特种医学   7篇
外科学   68篇
综合类   1篇
一般理论   2篇
预防医学   59篇
药学   15篇
肿瘤学   33篇
  2023年   3篇
  2022年   3篇
  2021年   12篇
  2020年   8篇
  2019年   10篇
  2018年   7篇
  2017年   18篇
  2016年   5篇
  2015年   20篇
  2014年   28篇
  2013年   29篇
  2012年   52篇
  2011年   47篇
  2010年   30篇
  2009年   27篇
  2008年   33篇
  2007年   19篇
  2006年   21篇
  2005年   30篇
  2004年   7篇
  2003年   16篇
  2002年   8篇
  2001年   1篇
  1999年   3篇
  1998年   5篇
  1997年   4篇
  1996年   2篇
  1995年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
排序方式: 共有454条查询结果,搜索用时 15 毫秒
11.
ObjectiveAtherogenesis involves an inflammatory process that occurs early in life even though clinical symptoms are not observed until adulthood. Two important protective factors for low-grade inflammation may be physical activity (PA) and fitness. We examined the independent associations of objective and subjective measurements of PA and fitness with low-grade inflammation in European adolescents.MethodsA total of 1045 adolescents, aged from 12.5 to 17.5 years old from 10 European cities, were selected from the HELENA-Cross-Sectional Study. Objectively-measured and self-reported PA variables were obtained by accelerometry and the International PA Questionnaire for Adolescents, respectively. Overall, cardiorespiratory, muscular and motor fitness variables were assessed by standardized field-based fitness tests and the International Fitness Scale. C-reactive protein (CRP), complement factors 3 (C3) and 4 (C4), interleukin-6 and TNF-α inflammatory markers were measured.ResultsObjectively-measured vigorous PA was inversely associated with C3 (β = ?0.094, P = 0.021) but it did not remain significant after any objective fitness indicator was included in the model. Other objectively measured or self-reported assessments of PA were not significantly associated with inflammatory markers. All objective measures of fitness were inversely associated with CRP, C3 and C4, whereas only self-reported motor fitness remained significantly associated with C3, C4 and TNF-α. All these observations were independent of age, sex, city and body mass index or waist circumference.ConclusionHigh PA in adolescence may play an indirect role on lessening low-grade inflammation through improvements in fitness.  相似文献   
12.
13.
14.
Older migrants may be one of the most vulnerable populations during the coronavirus pandemic, yet the degree of impact remains largely unknown. This study explores (1) the consequences of the coronavirus pandemic for older Chinese migrants in Belgium and the Netherlands in terms of increased loneliness and its risk factors (reduced in-person contact, decreased social participation, feelings of existential threat) and protective factors (increased non-in-person contact, more individual activities), and (2) which risk and protective factors have contributed to the incidence and prevention of higher loneliness levels. Using quantitative data of a survey among 98 Chinese migrants aged 50 years and older in Belgium (n = 84) and the Netherlands (n = 14), the findings first indicate that the coronavirus pandemic has a significant impact on older Chinese migrants’ lives. One in five experienced more loneliness. Second, reduced social participation (measured as less frequent participation in outdoor group activities) and financial insecurity (measured as experiencing financial difficulties) lead to higher than pre-pandemic loneliness levels. Problem-focused coping strategies (measured as increased non-in-person contact, via telephone or social media) and emotion-focused coping (measured as finding distraction through increased participation in individual activities) were not found to protect against increased loneliness in the pandemic. Two practical implications for loneliness interventions for older Chinese migrants are put forward. Organizing COVID-19-safe social participation activities and paying more attention to older Chinese migrants’ financial situation can be beneficial when addressing higher levels of loneliness due to the coronavirus pandemic.  相似文献   
15.
Family Group Conferencing is a new decision model to assign caring responsibilities among various actors in society, including the client, social networks, and professionals. The process of Family Group Conferencing in coercive psychiatry is delicate; nevertheless, it paves the way for courageous conversation, and it facilitates ownership over the problematic situation and the formation of a partnership. Different actors co-construct an open and new actuality by taking initiative during and after the Family Group Conference, by confronting each other; by sharing information about the situation and so forming a partnership. Family Group Conferencing requires a change in thinking and doing of mental health professionals that is close to nursing; instead of focusing on the treatment of individual clients, they support primary groups to deal with the situation at hand.  相似文献   
16.
OBJECTIVE: Spondylarthritis (SpA) and rheumatoid arthritis (RA) have different patterns of bone damage, with more pronounced bone erosions in RA. The RANK/RANKL/osteoprotegerin (OPG) system plays a central role in bone resorption by promoting the maturation and activation of osteoclasts. To assess the potential role of this system in the distinct bone phenotype, we studied the synovial expression of these mediators in SpA and RA peripheral synovitis. METHODS: Synovial biopsy specimens were obtained from the actively inflamed peripheral joints of 35 patients with SpA and 19 patients with RA. Paired synovial biopsy samples were obtained from 24 patients with SpA after tumor necrosis factor alpha (TNFalpha) blockade. Synovial tissue sections were immunostained for RANKL, OPG, RANK, and TRAP and assessed by semiquantitative scoring and digital image analysis. RESULTS: After extensive validation of the reactivity and specificity of the antibodies, we demonstrated the abundant expression of RANKL and OPG in SpA synovitis. RANKL was expressed by both fibroblast-like synoviocytes and sublining T lymphocytes. RANK-positive osteoclast precursors but no mature TRAP-positive osteoclasts were present in the inflamed tissue. The expression of these mediators was not different between patients with nonpsoriatic SpA, patients with psoriatic SpA, and patients with RA, was not related to the degree of systemic or local inflammation, and was not significantly modulated by highly effective treatment with TNFalpha blockers. Only the subset of patients with the best systemic response to TNFalpha blockade had decreased RANKL expression in the intimal lining layer. CONCLUSION: The relative protection against bone erosions in SpA cannot be explained by qualitative or quantitative differences in the synovial expression of RANKL, OPG, and RANK. The abundant expression of these factors in SpA peripheral synovitis is largely disconnected from systemic and local inflammation.  相似文献   
17.
Background As the prevalence of chronic disease amongst older workers is high and increasing, it is important to know if the large subgroup of older workers with chronic disease has specific needs when it comes to prolonging participation in paid work. Objectives To investigate differences and similarities in predictors of having paid work in workers aged 55+ with and without chronic disease. Methods Workers aged 55–62 years were selected from the 2002–2003 cohort of the Longitudinal Aging Study Amsterdam (n = 333). Potential predictors were: health, personality, work characteristics, and demographics. Per potential predictor, a logistic regression coefficient for ‘having paid work in 2005–2006’ was calculated for workers with and without chronic disease. A pooled estimate was computed and differences between the pooled estimate and the coefficients were tested. Results Follow-up data were available for 95 %, of whom 67 % still had paid work. Predictors of having paid work were similar for workers with and without chronic diseases, except for physical workload (χ2 = 5.37; DF = 1) and psychosocial resources at work (χ2 = 5.94; DF = 1). Having more psychosocial resources (OR = 3.57; 95 %CI 1.33–10.0) was predictive for having paid work in workers with chronic disease and not in workers without chronic disease. Lower age, more weekly working hours, no functional limitations, fewer depressive symptoms, lower neuroticism scores, and more sense of mastery were significantly associated with having paid work in all workers. Conclusions Differences between predictors of having paid work between workers with and without chronic disease should be taken into account when aiming to prevent exit from the workforce. In particular the vulnerable subgroup of older workers with chronic disease and low psychosocial resources at work is more likely to quit working.  相似文献   
18.
Superiority in visual search for individuals diagnosed with autism spectrum disorder (ASD) is a well-reported finding. We administered two visual search tasks to individuals with ASD and matched controls. One showed no difference between the groups, and one did show the expected superior performance for individuals with ASD. These results offer an explanation, formulated in terms of load theory. We suggest that there is a limit to the superiority in visual search for individuals with ASD, related to the perceptual load of the stimuli. When perceptual load becomes so high that no additional task-(ir)relevant information can be processed, performance will be based on single stimulus identification, in which no differences between individuals with ASD and controls have been demonstrated.  相似文献   
19.
Type 2 diabetes mellitus has recently been linked to an increased fracture risk. Since bone mass seems to be normal to elevated in patient with type 2 diabetes, the increased fracture risk is thought to be due to both an increased falling frequency and decreased bone quality. The increased falling frequency is mainly a result of complications of the disease such as a retinopathy and polyneuropathy. Bone quality is affected through changes in bone shape, bone micro-architecture, and in material properties such as bone mineralization and the quality of collagen. Commonly used methods for predicting fracture risk such as dual energy X-ray absorptiometry and fracture risk assessment tools are helpful in patients with type 2 diabetes mellitus, but underestimate the absolute fracture risk for a given score. New imaging modalities such as high resolution peripheral quantitative computed tomography are promising for giving insight in the complex etiology underlying the fragility of the diabetic bone, as they can give more insight into the microarchitecture and geometry of the bone. We present an overview of the contributing mechanisms to the increased fracture risk and the usefulness of imaging modalities and risk assessment tools in predicting fracture risk in patients with type 2 diabetes.  相似文献   
20.
BACKGROUND & AIMS: Fatty acids are natural ligands of the peroxisome proliferator-activated receptor alpha (PPARalpha). Synthetic ligands of this nuclear receptor, i.e., fibrates, induce the hepatic expression of the multidrug resistance 2 gene (Mdr2), encoding the canalicular phospholipid translocator, and affect hepatobiliary lipid transport. We tested whether fasting-associated fatty acid release from adipose tissues alters hepatic transporter expression and bile formation in a PPARalpha-dependent manner. METHODS: A 24-hour fasting/48-hour refeeding schedule was used in wild-type and Pparalpha((-/-)) mice. Expression of genes involved in the control of bile formation was determined and related to secretion rates of biliary components. RESULTS: Expression of Pparalpha, farnesoid X receptor, and liver X receptor alpha genes encoding nuclear receptors that control hepatic bile salt and sterol metabolism was induced on fasting in wild-type mice only. The expression of Mdr2 was 5-fold increased in fasted wild-type mice and increased only marginally in Pparalpha((-/-)) mice, and it normalized on refeeding. Mdr2 protein levels and maximal biliary phospholipid secretion rates were clearly increased in fasted wild-type mice. Hepatic expression of the liver X receptor target genes ATP binding cassette transporter a1 (Abca1), Abcg5, and Abcg8, implicated in hepatobiliary cholesterol transport, was induced in fasted wild-type mice only. However, the maximal biliary cholesterol secretion rate was reduced by approximately 50%. CONCLUSIONS: Induction of Mdr2 expression and function is part of the PPARalpha-mediated fasting response in mice. Fasting also induces expression of the putative hepatobiliary cholesterol transport genes Abca1, Abcg5, and Abcg8, but, nonetheless, maximal biliary cholesterol excretion is decreased after fasting.  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