La investigación biomédica sobre abuso de sustancias a través de la base de datos Medline (2006-2010)

El Abuso de sustancias es uno de los principales problemas sociales y de salud pública a escala mundial. Este estudio analiza la investigación científica sobre los trastornos relacionados con sustancias generado a lo largo del período 2006-2010 así como sus implicaciones sociales. A partir de los artículos científicos de la base de datos Medline relacionados con seis de las principales sustancias de abuso (alcohol, tabaco, opioides, cocaína, marihuana y anfetaminas) se construyó una base de datos mediante el procesamiento de la información bibliográfica de los artículos recuperados. Asimismo se efectuó un análisis cuantitativo de los términos MeSH asignados a los documentos considerando los siguientes aspectos: descriptores, enfermedades, género, edad, países y catálogo MeSH. Se han identificado 52.175 documentos. El 55,18% de ellos están relacionados con trastornos por consumo de tabaco; 38,63% se vinculan con trastornos relacionados con el alcohol; 6,45% con los trastornos relacionados con los opioides; 4,1% para los trastornos relacionados con la cocaína; 2,64% para el abuso de la marihuana y el 1,84% a los trastornos relacionados con las anfetaminas. La Epidemiología y la Psicología son las principales áreas asignadas a los documentos. Cabe resaltar que la atención investigadora ha pasado de estar centrada en las pasadas décadas en los aspectos farmacológicos y el tratamiento, a incidir en la prevención, la identificación de los efectos adversos y los factores de riesgo. Así la exposición prenatal al consumo de sustancias, la salud pública (tabaco y alcohol) y la detección de abuso de drogas (opiáceos, cocaína, marihuana y anfetaminas) son otras áreas de investigación remarcables.Substance abuse is one of the main social and public health problems worldwide. This study analyzes scientific research on substance-related disorders generated throughout the 2006-2010 period and its social implications. Scientific papers from Medline database involving the main substances abused (alcohol, tobacco, cocaine, opioids, marijuana and amphetamine) were taken into account. A database was constructed by processing bibliographic information of retrieved items. A quantitative analysis of the MeSH terms assigned to the documents was carried out by classifying the following topics: qualifiers, diseases, gender, age related terms, countries and generalized MeSH. 52,175 documents were identified. 55.18% of these are related to tobacco use disorders; 38.63% to alcohol-related disorders; 6.45% to opioid-related disorders; 4.1% to cocainerelated disorders; 2.64% to marijuana abuse and 1.84% to amphetamine-related disorders. Epidemiology and psychology are the main generalized terms assigned to the documents. It should be stressed that the research focus has shifted from pharmacological aspects and treatment in the past decades, to influence the prevention, identification of adverse effects and risk factors. Pregnancy disorders and prenatal exposure to substance use, public health (tobacco and alcohol) and substance abuse detection (opioids, cocaine, marijuana and amphetamines) are other research areas to be stressed

Comparative analysis between different approaches for single-phase PLLs

"In press"This paper presents a comparative analysis between two distinct synchronizing circuits, which are usually applied as the core of control algorithms for single-phase power quality applications. One of these synchronizing circuits corresponds to a single-phase Phase-Locked Loop (PLL), implemented in α-β coordinates (αβ-PLL), whereas the other one corresponds to the Enhanced PLL (E-PLL). The major contribution of this paper is to present a single-phase PLL oriented to power quality applications, with a very simple structure, capable to be synchronized with the fundamental component of an input signal (voltage or current), even considering substantial disturbances, such as, frequency deviations, phase shifts, harmonic components and amplitude variations. Simulation and experimental results, involving these two synchronizing circuits submitted to three different test cases, are provided in order to compare their transient and steady-state performance. Moreover, it is also presented a comparison involving the processing speed and memory requirements of these synchronizing circuits in the DSP TMS320F28335

On the Physical Vapour Deposition (PVD): evolution of magnetron sputtering processes for industrial applications

Advanced coatings play an important role in a wide range of industrial applications. These coatings are commonly used in machining tools due to their high hardness and wear resistance, but also can be applied in jewellery and decorative purposes. Deposition techniques have seen a strong evolution as result of the directly related devices, control evolution and software. Several variants have been developed around the main techniques: arc evaporation and sputtering. The coatings produced present significant differences in their characteristics, namely in terms of structure, mechanical properties and surface morphology. Depending on the substrate material and application, the deposition process needs to be properly selected, providing the particular characteristics requested. This paper intends to do a critical review of the evolution of the advanced coatings deposition process, mainly focused on the Physical Vapour Deposition (PVD) process, particularly in the Magnetron Sputtering technique, which is able to produce smooth surfaces, using lower temperatures, presenting excellent mechanical and tribological properties and having very good adhesion to the main materials used as substrate.Fundação para a Ciência e a Tecnologia | Ref. UID/EMS/0615/2016LAETA/CETRIB/INEGI Research Center-FLAD – Fundação Luso-Americana para o Desenvolvimento | Ref. 116/201

POLCA control in two-stage production systems

POLCA (Paired-cell Overlapping Loops of Cards with Authorization) is a decision support system for material flow control under Quick Response Manufacturing. It operates in the context of low-volume, high-mix, and cellular manufacturing. While there is an increasing literature on POLCA performance, current studies usually assume full availability of components (or parts) at assembly stations, neglecting parts manufacturing and feeding. Therefore, this study uses simulation to assess POLCA performance in a two-stage production system, where at the first stage parts are manufactured and at the second, they are assembled into end-products. The study demonstrates that using POLCA to control both production stages, manufacturing and assembly, significantly outperforms the use of POLCA at the assembly stage only, leading to important reductions of the total throughput time of orders and on the percentage of tardy orders. Statistical analysis of our results was conducted using ANOVA.info:eu-repo/semantics/publishedVersio

Active power conditioner based on a voltage source converter for harmonics and negative sequence components compensation in electrified railway systems

The electrification of railway systems has always presented major challenges to the public electrical power systems. Electric locomotives are usually supplied by a single phase AC catenary, causing unbalance and the appearance of negative sequence components (NSCs) in the three phase electrical power grids. In addition, the traction power system of the electric locomotive is usually comprised by uncontrolled rectifiers to convert AC voltage to DC voltage, which produces high levels of current harmonics. Consequently, the operation of electric locomotives causes serious power quality problems to the public electrical power systems. This paper evaluates the use of Shunt Active Power Conditioners (SAPCs) to compensate power quality problems in single phase 25 kV, 50 Hz railway traction substations, when using the conventional V/V or the Scott traction power transformer between the catenary and the public electrical power systems.This work has been supported by COMPETE: POCI-01-0145–FEDER–007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the H2020 EU project 777515 - IN2STEMPO. Mohamed Tanta was supported by FCT PhD grant with the reference PD/BD/127815/2016.info:eu-repo/semantics/publishedVersio

Integrated structural safety analysis of San Francisco Master Gate in the Fortress of Almeida

After more than 300 years of being exposed to human and nature actions the Master Gate of San Francisco in Almeida, Portugal, has sustained visible extended damage. Although its importance, as a historical monument, is undeniable, no attempts have been done so far to determine its level of safety. In this article, several models are developed in order to achieve this goal. A brief description of the Gate's history is presented followed by a summary of the inspection and diagnosis procedures employed in this study and the results obtained from them. Later, the type of numerical models selected are discussed as well as the methodologies used to represent damage. Finally results from the numerical models are presented in a first attempt to identify the safety level of this historic construction. Results indicate that although the structure has lost a great percentage of its original capacity is still safe.This work was financed by FEDER funds through the Competitiveness Factors Operational Programme - COMPETE and by national funds through FCT - Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633.info:eu-repo/semantics/publishedVersio

Avaliações subjetivas e relacionais: o equívoco do sistema avaliativo docente para a qualidade dos cursos de pós-graduação MBA

The purpose of this paper was to analyze, from the point of view of the coordination of the programs, how and why the professors evaluations carried out by the students at the end of the courses taught can influence the quality of the lato sensu postgraduate courses in business administration called MBAs. In a qualitative approach, a case study was conducted where individual in-depth interviews were conducted with program coordinators involving more than 6,000 students and 500 teachers within the city of São Paulo. The content analysis of the interviews with the coordinators showed that the evaluation system, currently practiced by the teaching institution of the case studied, is much more associated to an attempt to measure relational and behavioral aspects between student-teacher than to aspects of improvement of quality of the programs or their learning objectives. It was not evident the relation of the accomplishment of the teacher evaluations with a logic of permanent improvement of quality. As an additional output of the research, the main components that could be included in an evaluation system that really focused on a continuous quality improvement program were identified.Key- words: MBA; executive education; teacher evaluation; quality.Este trabalho teve por objetivo analisar, sob a ótica da coordenação de curso, como e porque as avaliações docentes realizadas pelos alunos ao final das disciplinas ministradas podem auxiliar o gestor a melhorar a qualidade dos cursos de pós-graduação lato sensu em Administração de Empresas denominados MBAs. Numa abordagem qualitativa, foi conduzido um estudo de caso em que foram realizadas entrevistas individuais em profundidade com os coordenadores dos programas que envolvem mais de 6.000 alunos e 500 professores da cidade de São Paulo. A análise de conteúdo das entrevistas com os coordenadores mostrou que o sistema avaliativo, atualmente praticado pela instituição de ensino do caso estudado, está mais associado a uma tentativa de mensuração de aspectos relacionais e comportamentais entre aluno-professor do que a aspectos de melhoria de qualidade dos programas ou aos seus objetivos de aprendizagem. Não ficou evidente a relação da realização das avaliações docentes com uma lógica de melhoria permanente de qualidade. Como saída adicional da pesquisa foram identificados os principais componentes que poderiam constar num sistema de avaliação que tivesse foco num programa contínuo de melhoria de qualidade.Palavras-chave: MBA; educação executiva; avaliação docente; qualidade

Experimental validation of a current-source converter with reduced dc-link operating as shunt active power filter

Nowadays, the majority of electronic equipment behaves as nonlinear loads, introducing power quality problems into the power grid, namely, current harmonics and low power factor. These problems contribute to reduce the efficiency of the power grid and can cause malfunctioning of sensitive loads connected to the power grid. Therefore, it is important to develop power electronics solutions capable to mitigate these power quality problems. In this context, this paper presents a novel single-phase shunt active power filter (SAPF) based on a current-source converter, where the key differencing factor, when compared with the conventional approach, is the reduced dc-link. As the proposed topology requires a reduced dc-link, it represents a relevant advantage, requiring a less bulky inductance in the dc-link, reducing the losses, cost, and volume. The proposed SAPF with reduced dc-link is introduced in detail along the paper, and a comprehensive comparison with the conventional SAPF is established based on computer simulations. Besides, an experimental validation is carried out with a developed laboratory prototype, validating the main advantages of the proposed SAPF with reduced dc-link.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017 and the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation

Stability of hybrid versus vaccine immunity against BA.5 infection over 8 months

© 2022 Elsevier Ltd. All rights reserved.The coverage of SARS-CoV-2 vaccination in large parts of the world, together with the high number of breakthrough infections, especially following the emergence of Omicron subvariants, makes hybrid immunity (resulting from vaccine and infection) common. Hybrid immunity, particularly after BA.1 or BA.2 infection, confers substantial protection against the BA.5 infection. However, although the waning of protection afforded by natural infection in non-vaccinated individuals or by vaccination has been well documented, the stability of hybrid immunity, specifically against the BA.5 subvariant, now dominant in many countries, has not been thoroughly addressed.info:eu-repo/semantics/publishedVersio

A comprehensive comparison of voltage and current control techniques for three-phase VSI converters

Converting electrical energy from direct current to alternate current, or vice versa, is one of the most frequently performed tasks in today’s electrical systems. The Voltage Source Inverter (VSI) is the most widely used topology to accomplish this task. This paper compares the performance of three control algorithms for voltage source inverter (VSI) with PI, PR and MP control algorithms were applied for voltage control and current control. For voltage control the VSI synthesizes the sinusoidal voltage system for an islanded application. In current control the VSI injects energy into the power grid by synthesizing sinusoidal currents. A general comparison is made of the performance of the three control algorithms under the presented conditions, helping to choose the control algorithm to use in a given application.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation