29,474 research outputs found

    Weak values and the quantum phase space

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    We address the issue of how to properly treat, and in a more general setting, the concept of a weak value of a weak measurement in quantum mechanics. We show that for this purpose, one must take in account the effects of the measuring process on the entire phase space of the measuring system. By using coherent states, we go a step further than Jozsa in a recent paper, and we present an example where the result of the measurement is symmetrical in the position and momentum observables and seems to be much better suited for quantum optical implementation.Comment: 07 pages, accepted for PR

    The Electronic States of Two Oppositely doped Mott Insulators Bilayers

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    We study the effect of Coulomb interaction between two oppositely doped low-dimensional tJ model systems. We exactly show that, in the one-dimensional case, an arbitrarily weak interaction leads to the formation of charge neutral electron-hole pairs. We then use two different mean-field theories to address the two-dimensional case, where inter-layer excitons also form and condense. We propose that this results in new features which have no analog in single layers, such as the emergence of an insulating spin liquid phase. Our simple bilayer model might have relevance to the physics of doped Mott insulator interfaces and of the new four layer Ba2CaCu4O8 compound.Comment: 4 pages, 1 figur

    AUTOMATED COLLECTION OF QUALITY-OF-LIFE DATA: TOUCH-SCREEN COMPUTER SYSTEMS IN PATIENTS WITH IMMUNE DISEASES

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    AUTOMATED COLLECTION OF QUALITY-OF-LIFE DATA: TOUCH-SCREEN COMPUTER SYSTEMS IN PATIENTS WITH IMMUNE DISEASES Claúdia Ribeiro1,2,3, Augusta Silveira4,3, Isabel Silva4, Catarina Ribeiro4, Carlos Vasconcelos2,3 1UCP, 2HSA/CHP, 3ICBAS/UP, 4UFP e 5HSMF. Universidade Católica Portuguesa (UCP), Porto. Hospital de Santo António, Centro Hospitalar do Porto (HSA/CHP), Porto. Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP), Porto. Universidade Fernando Pessoa (UFP), Porto. Hospital Santa Maria da Feira (HSMF), Porto. Background The increase of technological knowledge and methodology has allowed the practice of redirecting epidemiological research, particularly in the field of chronic disease. Although capable of controlling the accumulation of events and constraints imposed by the treatment can lead to a drastic change in quality of life (QoL) of subjects progressed to varying degrees of disability and death. In this perspective the Quality of Life Related to Health (HRQOL) has taken a leading role and its evaluation is indispensable in Medicine. Aim The aims of this study were (1) analyze the importance of HRQOL assessment as a tool for health promotion and a way of measuring the effectiveness of interventions in daily practice in patients with coexisting chronic immune system (PCSI), (2) evaluation of alternative methods for the automated collection of data on HRQOL and development of an electronic interface in sample of 320 patients, (3) creating a database to ascertain the epidemiological profile of PCSI, and identification of socio-economic, demographic and clinical data of these individuals, (4) using the QoL indicator as a predictor in decision treatment and use the preferences of patients. Methods A total of 473 patients with chronic diseases of the immune system, which were applied Graffar Index, SF-36v2, a demographic questionnaire and identification of clinical variables. Results The results of this investigation suggest that the demographic, socio-economic and clinics are associated with significant differences in QoL cumulative and chronic complications associated with different pathologies. The results verified the existence of significant correlations between the different diagnoses, duration of disease and therapy. In general, patients who have chronic diseases of the immune system such as rheumatoid arthritis, lupus, scleroderma, Bechet's disease, Sjögren's syndrome or infection with human immunodeficiency virus 1 or 2 showed a worse QoL than the general population. The derivations of preferences from the SF-36v2 exhibit strong correlations with the preferences measured with the SF-6D. Conclusions This suggests that both the application of the SF-36v2 as the SF-6D can be important sources of preferences to implement measures in economic evaluation in healthcare. HRQL can and should be integrated into immune clinical practice. The translation of graphical results given to the clinician at the beginning of the consultation, favors the rapid analysis of global values of the patient's HRQL. This assessment can be an excellent diagnostic tool to be used routinely in clinical practice or assisting in disease management and therapeutic decision making. Apresentador: Cláudia Ribeiro, Médica Dentista. Doutoranda, Faculdade de Medicina da Universidade de Santiago de Compostela

    HEALTH-STATE UTILITIES IN CHRONIC IMMUNE DISEASES: PILOT STUDY

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    HEALTH-STATE UTILITIES IN CHRONIC IMMUNE DISEASES: PILOT STUDY Claúdia Ribeiro1,2,3, Augusta Silveira4,3, Augusta Marques5, Catarina Ribeiro4, Isabel Santos6,2,3, Carlos Vasconcelos2,3 1UCP, 2HSA/CHP, 3ICBAS/UP, 4UFP, 5HPA e 6HSMF. Universidade Católica Portuguesa (UCP), Porto Hospital de Santo António, Centro Hospitalar do Porto (HSA/CHP), Porto. Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP), Porto. Universidade Fernando Pessoa (UFP), Porto. Hospital Privado da Arrábida (HPA), Porto. Hospital Santa Maria da Feira (HSMF), Porto. Background Utility scores are used to estimate Quality Adjusted Life Years (QALYs), applied in determining the cost-effectiveness of health care interventions. In studies where no preference based measures are collected, indirect methods have been developed to estimate utilities from clinical instruments. Aim The aim of this study was to evaluate a published method of estimating the Short Form-6D (SF-6D) (preference based) in patients with chronic immune diseases from Unidade de Imunologia Clínica do Hospital de Santo António - Centro Hospitalar do Porto and evaluate the impact of socio demographics economics and clinical characteristics on quality of life (QoL) and potential predictors for QoL improvements. Methods We enrolled 320 patients with chronic immune diseases (104 men and 226 women with a mean age: 45.21; 84 people living with HIV and 236 with chronic autoimmune diseases. All responders to the Portuguese SF-36 version 2.0 questionnaire can be assigned an SF-6D score provided the 11 items used in the SF-6D have been completed using a computerized administration. To assess socioeconomic status, we use the Graffer’s scale, clinical and demographic variables were assessed by a questionnaire specifically designed for the present study. Results The mean utility value was .595. Male, gender, young, single, individuals with high educational attainment level and Graffer’s scale Class high reported higher utility levels. As expected, those who takes therapeutics’ or have a higher length disease reported lower mean utility levels than those who were in a less severe stadium of the disease or without therapeutic. Conclusion This paper provides the first utilities obtained from a populations leave with chronic immune diseases. The preference-based measures used in this study distinguish patient groups with chronic immune diseases’ in terms of socio-demographics characteristics and clinical groups. The normative values can be used economic evaluation and clinical studies as they incorporate patient’s preferences and translate the value attribute to patients´ health state. Apresentador: Cláudia Ribeiro, Médica Dentista. Doutoranda, Faculdade de Medicina da Universidade de Santiago de Compostela

    AUTOMATED COLLECTION OF QUALITY-OF-LIFE DATA: TOUCH-SCREEN COMPUTER SYSTEMS IN PATIENTS WITH IMMUNE DISEASES

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    AUTOMATED COLLECTION OF QUALITY-OF-LIFE DATA: TOUCH-SCREEN COMPUTER SYSTEMS IN PATIENTS WITH IMMUNE DISEASES Claúdia Ribeiro1,2,3, Augusta Silveira4,3, Isabel Silva4, Catarina Ribeiro4, Carlos Vasconcelos2,3 1UCP, 2HSA/CHP, 3ICBAS/UP, 4UFP e 5HSMF. Universidade Católica Portuguesa (UCP), Porto. Hospital de Santo António, Centro Hospitalar do Porto (HSA/CHP), Porto. Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP), Porto. Universidade Fernando Pessoa (UFP), Porto. Hospital Santa Maria da Feira (HSMF), Porto. Background The increase of technological knowledge and methodology has allowed the practice of redirecting epidemiological research, particularly in the field of chronic disease. Although capable of controlling the accumulation of events and constraints imposed by the treatment can lead to a drastic change in quality of life (QoL) of subjects progressed to varying degrees of disability and death. In this perspective the Quality of Life Related to Health (HRQOL) has taken a leading role and its evaluation is indispensable in Medicine. Aim The aims of this study were (1) analyze the importance of HRQOL assessment as a tool for health promotion and a way of measuring the effectiveness of interventions in daily practice in patients with coexisting chronic immune system (PCSI), (2) evaluation of alternative methods for the automated collection of data on HRQOL and development of an electronic interface in sample of 320 patients, (3) creating a database to ascertain the epidemiological profile of PCSI, and identification of socio-economic, demographic and clinical data of these individuals, (4) using the QoL indicator as a predictor in decision treatment and use the preferences of patients. Methods A total of 473 patients with chronic diseases of the immune system, which were applied Graffar Index, SF-36v2, a demographic questionnaire and identification of clinical variables. Results The results of this investigation suggest that the demographic, socio-economic and clinics are associated with significant differences in QoL cumulative and chronic complications associated with different pathologies. The results verified the existence of significant correlations between the different diagnoses, duration of disease and therapy. In general, patients who have chronic diseases of the immune system such as rheumatoid arthritis, lupus, scleroderma, Bechet's disease, Sjögren's syndrome or infection with human immunodeficiency virus 1 or 2 showed a worse QoL than the general population. The derivations of preferences from the SF-36v2 exhibit strong correlations with the preferences measured with the SF-6D. Conclusions This suggests that both the application of the SF-36v2 as the SF-6D can be important sources of preferences to implement measures in economic evaluation in healthcare. HRQL can and should be integrated into immune clinical practice. The translation of graphical results given to the clinician at the beginning of the consultation, favors the rapid analysis of global values of the patient's HRQL. This assessment can be an excellent diagnostic tool to be used routinely in clinical practice or assisting in disease management and therapeutic decision making. Apresentador: Cláudia Ribeiro, Médica Dentista. Doutoranda, Faculdade de Medicina da Universidade de Santiago de Compostela
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