587 research outputs found

    A simulation algorithm for optimization of mixture design applied to the assignment of weights in a goal programming problem

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    Ferreira, Ana Cristina, e outros (2023) - International conference on technology management and operations. - Lisboa : Universidade LusĂ­ada Editora. - ISBN 978-898-640-273-0.Experimental design approaches are essential for improving products and processes, and their use is often decisive in achieving a successful target result. Thus, mixture design is a method for designing experiments which considers that the result does not depend on the total amount but on the proportions of the components. Mixture design techniques are often applied to problems in food, beverage, pharmaceutical health, and cement-based materials, among others, and one may also use them to help solve multi-objective problems when the weights of the objective function components can interfere with the optimization process. Therefore, given the relevance of studies on mixture planning and the increasing use of methods and techniques to consider uncertainty, the objective of this study is to propose an approach to deal with uncertainties in the coefficients of polynomial objective functions for the optimization of mixture design problem considering optimization via Monte Carlo Simulation. Computational tests were made using R software with instances from a literature study on a waste paper recycling logistics problem where the assignment of model weights is part of the process. Comparing the results to those obtained using the General Algebraic Modeling System language and CPLEX solver, they showed that considering uncertainty in the coefficients of objective function assisted in minimizing the difference between the obtained results, allowing for improvement in the representation of several scenarios. The developed approach also provided solution possibilities to help choose the best weights to optimize goal programming problems

    In Vitro and In Vivo Investigation of the Efficacy of Arylimidamide DB1831 and Its Mesylated Salt Form - DB1965 - against Trypanosoma cruzi Infection

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    Chagas disease is caused by infection with the intracellular protozoan parasite Trypanosoma cruzi. At present, nifurtimox and benznidazole, both compounds developed empirically over four decades ago, represent the chemotherapeutic arsenal for treating this highly neglected disease. However, both drugs present variable efficacy depending on the geographical area and the occurrence of natural resistance, and are poorly effective against the later chronic stage. As a part of a search for new therapeutic opportunities to treat chagasic patients, pre-clinical studies were performed to characterize the activity of a novel arylimidamide (AIA - DB1831 (hydrochloride salt) and DB1965 (mesylate salt)) against T.cruzi. These AIAs displayed a high trypanocidal effect in vitro against both relevant forms in mammalian hosts, exhibiting a high selectivity index and a very high efficacy (IC50 value/48 h of 5–40 nM) against intracellular parasites. DB1965 shows high activity in vivo in acute experimental models (mouse) of T.cruzi, showing a similar effect to benznidazole (Bz) when compared under a scheme of 10 daily consecutive doses with 12.5 mg/kg. Although no parasitological cure was observed after treating with 20 daily consecutive doses, a combined dosage of DB1965 (5 mg/kg) with Bz (50 mg/kg) resulted in parasitaemia clearance and 100% animal survival. In summary, our present data confirmed that aryimidamides represent promising new chemical entities against T.cruzi in therapeutic schemes using the AIA alone or in combination with other drugs, like benznidazole

    Noncompliance in people living with HIV: accuracy of defining characteristics of the nursing diagnosis

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    ABSTRACT Objective: to evaluate the accuracy of the defining characteristics of the NANDA International nursing diagnosis, noncompliance, in people with HIV. Method: study of diagnostic accuracy, performed in two stages. In the first stage, 113 people with HIV from a hospital of infectious diseases in the Northeast of Brazil were assessed for identification of clinical indicators of noncompliance. In the second, the defining characteristics were evaluated by six specialist nurses, analyzing the presence or absence of the diagnosis. For accuracy of the clinical indicators, the specificity, sensitivity, predictive values and likelihood ratios were measured. Results: the presence of the noncompliance diagnosis was shown in 69% (n=78) of people with HIV. The most sensitive indicator was, missing of appointments (OR: 28.93, 95% CI: 1.112-2.126, p = 0.002). On the other hand, nonadherence behavior (OR: 15.00, 95% CI: 1.829-3.981, p = 0.001) and failure to meet outcomes (OR: 13.41; 95% CI: 1.272-2.508; P = 0.003) achieved higher specificity. Conclusion: the most accurate defining characteristics were nonadherence behavior, missing of appointments, and failure to meet outcomes. Thus, in the presence of these, the nurse can identify, with greater security, the diagnosis studied

    Áudios para aulas de Química: uma anålise do Portal Dia a Dia Educação

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    A utilização de ĂĄudios em sala de aula nĂŁo tem sido muito utilizada nos Ășltimos anos, entretanto existem portais que disponibilizam esse recurso como material didĂĄtico. Um destes portais Ă© o Dia a Dia Educação da Secretaria do Estado do ParanĂĄ-SEED. Assim este artigo apresenta uma anĂĄlise realizada a partir de ĂĄudios que estĂŁo disponibilizados nesse portal. Nossa intenção foi verificar a funcionalidade e a recepção dos estudantes para este tipo de recurso. As avaliaçÔes demonstram que Ă© possĂ­vel utilizar esse recurso em sala de aula, entretanto Ă© preciso superar algumas dificuldades tĂ©cnicas impostas pelos recursos tecnolĂłgicos oferecidos Ă  professores e estudantes nas escolas do ParanĂĄ

    ERICA: patterns of alcohol consumption in Brazilian adolescents

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    ABSTRACT OBJECTIVE To describe the patterns of alcohol consumption in Brazilian adolescents. METHODS We investigated adolescents who participated in the Study of Cardiovascular Risks in Adolescents (ERICA). This is a cross-sectional, national and school-based study, which surveyed adolescents of 1,247 schools from 124 Brazilian municipalities. Participants answered a self-administered questionnaire with a section on alcoholic beverages consumption. Measures of relative frequency (prevalence), and their 95% confidence intervals, were estimated for the following variables: use of alcohol beverages in the last 30 days, frequency of use, number of glasses or doses consumed in the period, age of the first use of alcohol, and most consumed type of drink. Data were estimated for country and macro-region, sex, and age group. The module survey of the Stata program was used for data analysis of complex sample. RESULTS We evaluated 74,589 adolescents, who accounted for 72.9% of eligible students. About 1/5 of adolescents consumed alcohol at least once in the last 30 days and about 2/3 in one or two occasions during this period. Among the adolescents who consumed alcoholic beverages, 24.1% drank it for the first time before being 12 years old, and the most common type of alcoholic beverages consumed by them were drinks based on vodka, rum or tequila, and beer. CONCLUSIONS There is a high prevalence of alcohol consumption among adolescents, as well as their early onset of alcohol use. We also identified a possible change in the preferred type of alcoholic beverages compared with previous research

    Dansyl Fluorophore Functionalized Hierarchically Structured Mesoporous Silica Nanoparticles As Novel Latent Fingerprint Development Agents

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    A nanostructured hybrid material based on mesoporous silica nanoparticles (MCM-41) functionalized with chitosan and a fluorescent dye (dansylglycine), designated MCM-41@Ch@DnsGly, was synthesized and characterized with a view to its application for the visualization of latent fingerprints. These nanoparticles were applied as latent fingerprint developers for marks on surfaces of diverse chemical composition, topography, optical characteristics, and spatially variant nature, typical of forensically challenging evidence. For quality assessment of the enhanced fingermarks, the developed images were analyzed holistically using the UK Home Office scale, forensic protocols and, in terms of their constituent features (minutiae), using forensic software. Across a substantive collection of marks deposited on chemically diverse surfaces and subject to complex environmental and temporal histories, 94% of the enhanced images presented sufficient minutiae for comparison with model dactyloscopy images. This novel nanomaterial presents enhanced performance with significant promise for superior exploitation by forensic practitioners in the acquisition and analysis of crime scene evidence
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