88 research outputs found

    Stability of the unique continuation for the wave operator via Tataru inequality and applications

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    In this paper we study the stability of the unique continuation in the case of the wave equation with variable coefficients independent of time. We prove a logarithmic estimate in a arbitrary domain of Rn+1{\mathbb R}^{n+1}, where all the parameters are calculated explicitly in terms of the C1C^1-norm of the coefficients and on the other geometric properties of the problem. We use the Carleman-type estimate proved by Tataru in 1995 and an iteration for locals stability. We apply the result to the case of a wave equation with data on a cylinder an we get a stable estimate for any positive time, also after the first conjugate point for the geodesics of the metric related to the variable coefficients.Comment: The version v1 of this preprint is an extended version that contains more details than the "journal version", that is, the version v2, of the pape

    El modelo BGK con potencial confinante: existencia, comportamiento asintótico y equilibrios Maxwellianos periódicos en tiempo

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    Un modelo aproximado de la ecuaci´on de Boltzmann en presencia de un potencial externo, que mantiene su no linealidad y sus propiedades cualitativas, es la ecuación de Boltzmann-BGK con potencial externo. Para esta ecuación estudiamos la existencia de solución, la estabilidad de sus estados estacionarios y la convergencia a los estados de equilibrio. Para un dato inicial con masa, entropía y energía total acotadas probamos existencia de solución y convergencia fuerte en L1 hacia los estados de equilibrio Maxwellianos, mediante argumentos de compacidad. Un caso especialmente interesante es el que se plantea cuando se considera un potencial externo armónico, ya que aparece toda una familia de estados estacionarios dependientes del tiempo de forma periódica. Este fenómeno es compartido con la ecuación de Boltzmann y con algunos otros modelos cinéticos. Para todos estos modelos probamos la multiestabilidad de dichos estados y ofrecemos condiciones para identificar el estado de equilibrio

    Avaliação da qualidade de vida de pacientes com obesidade grave submetidos à cirurgia bariátrica em um sistema público de saúde

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    OBJECTIVES: To assess QoL of obese patients in the Brazilian public healthcare system, before and after bariatric surgery, and to determine the appropriateness of the Moorehead-Ardelt Questionnaire II (M-A-QoLQII) compared with the Short-Form Health Survey (SF-36). SUBJECTS AND METHODS: Forty-one severe obese patients in a waiting-list, and 84 patients who underwent bariatric surgery were included. Correlations were tested and reliability determined by the Cronbach's coefficient. RESULTS: BMI differed between the pre- and post-surgery groups (52.3 ± 8.3 kg/m² vs. 32.5 ± 6.4 kg/m², p < 0.001). The latter showed better scores in the SF-36 domains than in the pre-surgery. SF-36 and M-A-QoLQII categories were correlated (r = 0.53, 0.49 and 0.47, for vitality, mental health, and general health domains, p < 0.001). In the logistic regression, age, previous BMI, and loss of excess weight were associated with functional capacity. CONCLUSIONS: The outcomes of bariatric surgery obtained in a Brazilian public healthcare center were successful. M-A-QoLII represents a useful tool to assess surgery outcomes, including QoL.OBJETIVOS: Avaliar a qualidade de vida de pacientes obesos do sistema público de saúde brasileiro antes e após cirurgia bariátrica e a adequação do questionário Moorehead-Ardelt II (M-A-QoLQII) em relação ao SF-36. SUJEITOS E MÉTODOS: Quarenta e um pacientes obesos graves em lista de espera e 84 submetidos à cirurgia bariátrica foram incluídos. Correlações foram testadas e confiabilidade determinada pelo coeficiente de Cronbach. RESULTADOS: O IMC diferiu entre os grupos pré- e pós-cirurgia (52,3 ± 8,3 kg/m² vs. 32,5 ± 6,4 kg/m², p < 0,001). O último apresentou melhores escores nos domínios do SF-36 que o pré-cirurgia. As categorias do SF-36 e M-A-QoLQII se correlacionaram (r = 0,53; 0,49; 0,47 para vitalidade, saúde mental e saúde geral, p 0,001). Na regressão logística, idade, IMC prévio e excesso de peso perdido associaram-se independentemente à capacidade funcional. CONCLUSÕES: Resultados da cirurgia bariátrica em centro de saúde público brasileiro foram promissores. O M-A-QoLQII representa ferramenta útil para avaliar seus resultados, inclusive a QV.Federal University of São Paulo Internal Medicine Department Division of EndocrinologyUNIFESP São Paulo Center for Health Economics Internal Medicine DepartmentUniversity of São Paulo School of Public Health Nutrition DepartmentUNIFESP, Internal Medicine Department Division of EndocrinologyUNIFESP, São Paulo Center for Health Economics Internal Medicine DepartmentSciEL

    Pattern of antibiotic consumption in two Italian production chains differing by the endemic status for Porcine Reproductive and Respiratory Syndrome

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    The aim of this case study was to quantify antibiotic (AB) use in Italian weaning (W) and fattening (F) units differentiated for porcine reproductive and respiratory syndrome (PRRS) occurrence. Farms were classified as either PRRS negative (–) or PRRS positive (+) based on the circulation of the virus among the animals. In all the farms, the modified live PRRS virus (PRRSV) vaccine was provided to all the animals. In the PRRS– farms, the level of circulating antibodies was low, and the disease, in its clinical form, did not occur. In the PRRS+ farms, the level of circulating antibodies against the virus was high, and the disease was recurrent. Data regarding AB consumption were collected from 2017 to 2020, and the active compounds (ACs) were expressed as milligrams of AC/total kilogram of body weight (BW) produced. Each AC was classified into one of four categories according to the EuropeanMedicines Agency classification of ABs for prudent and responsible use in animals: Avoid, Restrict, Caution, and Prudence. Data regarding the ACs in each category were analyzed using a linear model that included production phase, PRRS status, and their interaction as factors. Performance parameters, average age of the pigs at the end of each phase, daily live weight gain, feed-to-gain ratio, total losses, cost index, and medication costs were significantly influenced by the PRRS chain. The use of class B ABs was not affected by production phase or PRRS status. Conversely, for class C ABs, interaction between the two factors (p = 0.02) was observed; W/PRRS+ and F/PRRS+ showed the greatest AB use for this class (p = 0.003). For class D ABs, the interaction was significant (p = 0.01); class C and D ABs were used more in the weaning (p = 0.07) than in the fattening phase (p = 0.003). For the weaning phase, the use of class C and D ABs was greater in the PRRS+ than in the PRRS– chain (p &lt; 0.01). In conclusion, PRRS status affected the growth of pigs and economic performance. Moreover, PRRS status significantly influenced the use of ABs during all the growing periods with the greatest impact being on the weaning phase

    Inside the history of Italian coloring industries. An investigation of ACNA dyes through a novel analytical protocol for synthetic dye extraction and characterization

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    The introduction of synthetic dyes completely changed the industrial production and use of colorants for art materials. From the synthesis of the first synthetic dye, mauveine, in 1856 until today, artists have enjoyed a wider range of colors and selection of chemical properties than was ever available before. However, the introduction of synthetic dyes introduced a wider variety and increased the complexity of the chemical structures of marketed dyes. This work looks towards the analysis of synthetically dyed objects in heritage collections, applying an extraction protocol based on the use of ammonia, which is considered favorable for natural anthraquinone dyes but has never before been applied to acid synthetic dyes. This work also presents an innovative cleanup step based on the use of an ion pair dispersive liquid–liquid microextraction for the purification and preconcentration of historical synthetic dyes before analysis. This approach was adapted from food science analysis and is applied to synthetic dyes in heritage science for the first time in this paper. The results showed adequate recovery of analytes and allowed for the ammonia-based extraction method to be applied successfully to 15 samples of suspected azo dyes from the Azienda Coloranti Nazionali e Affini (ACNA) synthetic dye collection, identified through untargeted HPLC-HRMS analyses

    Dyes of a Shadow Theatre: Investigating Tholu Bommalu Indian Puppets through a Highly Sensitive Multi-Spectroscopic Approach

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    Tholu Bommalu are typical leather puppets of the traditional Indian shadow theatre. Two of these objects are part of a collection in the International Puppets Museum “Antonio Pasqualino” (Palermo, Sicily, Italy), which can count on one hundred-seventy-three of artifacts. These Indian puppets were investigated to obtain information related to the use of dyes for their manufacturing through a multi-technical approach exploiting the combination of highly sensitive spectroscopic techniques. Wet cotton stubbons were used to entrap small particles of dyes on the fibers from the art objects for the consequent analyses. Visible Light Micro-Reflectance spectroscopy was employed for the preliminary identification of the molecular class of dyes directly on the swabs, while Surface Enhanced Raman Scattering allowed the identification of the specific dye. Several synthetic dyes belonging to different typologies of coloring compounds were identified. The study resulted in an interesting overview of dyes used in recent Tholu Bommalata manufacturing through the combination of micro-invasive techniques directly on the sampling substrate

    New advances in dye analyses. In situ gel-supported liquid extraction from paint layers and textiles for SERS and HPLC-MS/MS Identification

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    To date, it is still not possible to obtain exhaustive information about organic materials in cultural heritage without sampling. Nonetheless, when studying unique objects with invaluable artistic or historical significance, preserving their integrity is a priority. In particular, organic dye identification is of significant interest for history and conservation research, but it is still hindered by analytes’ low concentration and poor fastness. In this work, a minimally invasive approach for dye identification is presented. The procedure is designed to accompany noninvasive analyses of inorganic substances for comprehensive studies of complex cultural heritage matrices, in compliance with their soundness. Liquid extraction of madder, turmeric, and indigo dyes was performed directly from paint layers and textiles. The extraction was supported by hydrogels, which themselves can undergo multitechnique analyses in the place of samples. After extraction, Ag colloid pastes were applied on the gels for SERS analyses, allowing for the identification of the three dyes. For the HPLC-MS/MS analyses, re-extraction of the dyes was followed by a clean-up step that was successfully applied on madder and turmeric. The colour change perceptivity after extraction was measured with colorimetry. The results showed ΔE values mostly below the upper limit of rigorous colour change, confirming the gentleness of the procedure

    The cost of type 1 diabetes: a nationwide multicentre study in Brazil

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    Objective To determine the direct medical costs of type 1 diabetes mellitus (T1DM) to the National Brazilian Health-Care System (NBHCS) and quantify the contribution of each individual component to the total cost.Methods A retrospective, cross-sectional, nationwide multicentre study was conducted between 2008 and 2010 in 28 public clinics in 20 Brazilian cities. the study included 3180 patients with T1DM (mean age 22 year's +/- 11.8) who were surveyed while receiving health care from the NBHCS. the mean duration of their diabetes was 10.3 years (+/- 8.0). the costs of tests and medical procedures, insulin pumps, and supplies for administration, and supplies for self-monitoring of blood glucose (SMBG) were obtained from national and local health system sources for 2010-2011. Annual direct medical costs were derived by adding the costs of medications, supplies, tests, medical consultations, procedures and hospitalizations over the year preceding the interview.Findings the average annual direct medical cost per capita was 1319.15 United States dollars (US).TreatmentrelatedexpenditureUS). Treatment-related expenditure - US 1216.33 per patient per year represented 92.20% of total direct medical costs. Insulin administration supplies and SMBG (US696.78perpatientperyear)accountedfor52.82 696.78 per patient per year) accounted for 52.82% of these total costs. Together, medical procedures and haemodialysis accounted for 5.73% (US 75.64 per patient per year) of direct medical costs. Consultations accounted for 1.94% of direct medical costs (US$ 25.62 per patient per year).Conclusion Health technologies accounted for most direct medical costs of T1DM. These data can serve to reassess the distribution of resources for managing T1DM in Brazil's public health-care system.Farmanguinhos/Fundacao Oswaldo Cruz/National Health MinistryBrazilian Diabetes SocietyFundacao do Amparo a Pesquisa do Estado do Rio de JaneiroConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)State Univ Hosp Rio de Janeiro, BR-20551030 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilBauru Diabet Assoc, Bauru, BrazilJoinville Endocrinol & Diabet Inst, Joinville, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
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