40 research outputs found

    Study of the doubly charmed tetraquark T+cc

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    Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

    Predictors of resilience in older adults with lower limb osteoarthritis and persistent severe pain

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    Background Resilience refers to the process in which people function well despite adversity. Persistent severe pain may be considered an adversity in people with lower limb osteoarthritis (LLOA). The objectives of this study are: (1) to identify what proportion of older adults with LLOA and persistent severe pain show good functioning; and (2) to explore predictors of resilience. Methods Data from the European Project on OSteoArthritis (EPOSA) were used involving standardized data from six European population-based cohort studies. LLOA is defined as clinical knee and/or hip osteoarthritis. Persistent severe pain is defined as the highest tertile of the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index both at baseline and follow-up. Resilience is defined as good physical, mental or social functioning at follow-up despite having LLOA with persistent severe pain. Results In total, 95 (14.9%) out of 638 individuals with LLOA had persistent severe pain. Among these, 10 (11.0%), 54 (57.4%) and 49 (53.8%) had good physical, mental and social functioning, respectively. Only 4 individuals (4.5%) were resilient in all three domains of functioning. Younger age, male sex, higher education, higher mastery, smoking and alcohol use, higher physical activity levels, absence of chronic diseases, and more contacts with friends predicted resilience in one or more domains of functioning. Conclusions Few people with LLOA and persistent severe pain showed good physical functioning and about half showed good mental or social functioning. Predictors of resilience differed between domains, and might provide new insights for treatment

    Predictors of resilience in older adults with lower limb osteoarthritis and persistent severe pain

    No full text
    Background: resilience refers to the process in which people function well despite adversity. Persistent severe pain may be considered an adversity in people with lower limb osteoarthritis (LLOA). The objectives of this study are: (1) to identify what proportion of older adults with LLOA and persistent severe pain show good functioning; and (2) to explore predictors of resilience.Methods: data from the European Project on OSteoArthritis (EPOSA) were used involving standardized data from six European population-based cohort studies. LLOA is defined as clinical knee and/or hip osteoarthritis. Persistent severe pain is defined as the highest tertile of the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index both at baseline and follow-up. Resilience is defined as good physical, mental or social functioning at follow-up despite having LLOA with persistent severe pain.Results: in total, 95 (14.9%) out of 638 individuals with LLOA had persistent severe pain. Among these, 10 (11.0%), 54 (57.4%) and 49 (53.8%) had good physical, mental and social functioning, respectively. Only 4 individuals (4.5%) were resilient in all three domains of functioning. Younger age, male sex, higher education, higher mastery, smoking and alcohol use, higher physical activity levels, absence of chronic diseases, and more contacts with friends predicted resilience in one or more domains of functioning.Conclusions: few people with LLOA and persistent severe pain showed good physical functioning and about half showed good mental or social functioning. Predictors of resilience differed between domains, and might provide new insights for treatment

    The reverse metabolic syndrome in the elderly: Is it a “catabolic” syndrome?

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    Traditional risk factors of cardiovascular death in the general population, including body mass index (BMI), serum cholesterol, and blood pressure are also found to relate to outcomes in the geriatric population, but in a differing direction. A higher body mass index, hypercholesterolemia and hypertension are not harmful but even permit better survival at advancing age. This phenomenon is called "reverse epidemiology" or "risk factor paradox" and is also detected in a variety of chronic disease states such as chronic heart failure. Accordingly, a low BMI, blood pressure and cholesterol values are associated with a worse prognosis. Several possible causes are hypothesized to explain this elderly paradox, but this phenomenon remains controversial and its underlying reasons are poorly understood. The aim of this review is to recognize the factors behind this intriguing phenomenon and analyse the consequences that it can bring in the management of the cardiovascular therapy in elderly patient. Finally, a new phenotype identified as "catabolic syndrome" has been postulated
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