Escola Superior de Tecnologia e Gestão
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- 12º Congresso Nacional de Mecânica Experimental - Livro de ResumosPublication . Capela, Carlos; Correia, Mário Simões; Ruben, Rui
- 2-Hydroxy-4-methoxybenzaldehyde fromHemidesmus indicusis antagonistic toStaphylococcus epidermidisbiofilm formationPublication . Kannappan, Arunachalam; Durgadevi, Ravindran; Srinivasan, Ramanathan; Lagoa, Ricardo José Lucas; Packiavathy, Issac Abraham Sybiya Vasantha; Pandian, Shunmugiah Karutha; Ravi, Arumugam VeeraStaphylococcus epidermidis (SE) is an opportunistic nosocomial pathogen that accounts for recalcitrant device-related infections worldwide. Owing to the growing interest in plants and their secondary metabolites targeting bacterial adhesion, this study was intended to uncover the anti-biofilm potential of Hemidesmus indicus and its major constituent 2-hydroxy-4-methoxybenzaldehyde (HMB) against SE. The minimum biofilm inhibitory concentration (MBIC) of H. indicus root extract and HMB were found to be 500 and 250 µg ml−1, respectively. The results of time-dependent biofilm inhibition and mature biofilm disruption assays confirmed that HMB targets initial cell adhesion. Furthermore, interference by HMB in the expression of adhesin genes (icaA, aap and bhp) and biofilm components was associated with an increased susceptibility of SE to oxidative stress and antibiotics. To conclude, this study reports for the first time HMB as a potential drug against SE biofilms.
- 2ARTs – Decision Support System for Exercise and Diet Prescriptions in Cardiac Recovery PatientsPublication . Pereira, Andreia Alexandra Sousa; Martinho, Ricardo Filipe Gonçalves; Rijo, Rui Pedro Charters Lopes; Grilo, Carlos Fernando de AlmeidaThe global health care system is faced with a variety of complicated challenges, ranging from limited access and increasing expenses to an aging population causing increased pressure on healthcare systems. Healthcare professionals are seeking alternative approaches to provide fair access and sustain high-quality care for everyone as a result of these challenges. Patients have historically been restricted from accessing essential healthcare services due to traditional barriers like geographic distance, financial and resource limitations. Innovative solutions to these problems are starting to take shape, thanks to the growth of eHealth platforms that use technology to improve patient care. Through a comprehensive study of existing solutions in the healthcare domain, particularly in cardiology, we identified the need for a Decision Support System (DSS) that would empower physicians with valuable insights and facilitate informed physical and diet prescribing practices into Cardiac Rehabilitation Programmes (CRPs). The major goal of 2ARTs’ project is to create and implement a cardiac rehabilitation platform into a hospital's infrastructure. A key aspect of this platform is the integration of a decision support system designed to provide physicians with valuable information when prescribing individualized treatment prescriptions for each patient, minimizing the potential of human error. The DSS uses algorithms and predictive models to classify patients into distinct groups based on their features and medical history. This classification provides critical insights and additional knowledge to doctors, allowing them to make informed judgments regarding the most effective treatment options for each patient's cardiac rehabilitation journey. By using the power of data-driven analytics and machine learning, the DSS enables doctors to better understand each patient's needs and personalize treatment actions accordingly. In order to achieve the best possible results aligned with the goals of the project, a variety of approaches based on comprehensive studies were explored, specifically feature selection and feature reduction methods, where their performance metrics were evaluated, seeking the most effective solution. It was through this thorough analysis that Principal Component Analysis (PCA) emerged as the standout choice. PCA not only demonstrated superior outcomes in evaluation metrics, but also showcased excellent compatibility with the selected clustering algorithm along with the best results after an expert analysis. Moreover, with the analysis of the data types and features the dataset had, the K-Means algorithm produced the best results and was more adaptable to our dataset. We were able to identify useful insights and patterns within the data by employing both PCA and K-Means, opening the way for more accurate and informed decision-making in the 2ARTs project.
- 2ARTs: A Platform for Exercise Prescriptions in Cardiac Recovery PatientsPublication . Pereira, Andreia; Martinho, Ricardo; Pinto, Rui; Rijo, Rui; Grilo, CarlosDue to limited access, increasing costs and an ageing population, the global healthcare system faces significant coverage problems that call for innovative approaches. Health professionals are actively seeking alternative methods to provide care to an increasingly needy population, without increasing human effort and associated costs. eHealth platforms, which use technology to provide patient care, are emerging as transformative solutions for addressing these problems. This study is centered on the demand for a Decision Support System (DSS) in cardiology to enable doctors to prescribe individualized care inside Cardiac Rehabilitation Programmes (CRPs). The 2ARTs project’s main objective is to include a cardiac rehabilitation platform with a DSS within the hospital infrastructure. This DSS uses models to classify patients into different groups, delivering crucial information to assist with decisions regarding treatment. Regarding the DSS, Principal Component Analysis (PCA) emerged as a standout technique for dimensionality reduction, due to its interoperability with clustering algorithms and superior evaluation metrics. The most appropriate clustering technique was determined to be the K-means algorithm, which was supported by the experts analysis. In accordance with the goals of the 2ARTs project, this integration of PCA and K-means provides meaningful insights that improve reasoned decision-making.
- A 2D ray-tracing based model for wave propagation through forests at micro-and millimeter wave frequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo; Caldeirinha, Rafael F. S.This paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees’ re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- A 2D Ray-Tracing Based Model for Wave Propagation Through Forests at Micro-and Millimeter Wave FrequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo, Telmo Rui Carvalhinho Cunha, Telmo R.; Caldeirinha, RafaelThis paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees' re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- 2nd Leiria Young Scholars International Conference on Enterprise Law (Leiria-YSICEL). Proceedings.Publication . Cañete, Alejandro de Rosa; Panocca, Alfredo Jhunior Lazarte; Martínez, Irene Martínez; Castilho, Marília Vieira; Serrão, Marta; Zayas, Sandys Menoya; Conceição, Ana Filipa; Lambelho, Ana; Almeida, SusanaA II Young Scholars International Conference on Enterprise Law (YSICEL) pretendeu dar continuidade ao projeto que se iniciou com a primeira conferência, e que assenta em três pilares fundamentais: ser um espaço de acolhimento e de partilha para estudantes de mestrado e doutoramento e jovens investigadores (até 5 anos após a conclusão do doutoramento); promover a discussão sobre diferentes eixos do Direito Empresarial, como sejam o Direito dos Negócios, o Direito Laboral, o Direito da Insolvência, o Direito do Consumo, o Direito dos Contratos Comerciais ou da Propriedade Industrial e Direitos de Autor; criar uma conferência anual de qualidade, que possa trazer não só estudantes do Mestrado em Solicitadoria de Empresa da Escola Superior de Tecnologia e Gestão do Politécnico de Leiria, mas de todo o mundo. Estas são as atas do evento, que representam diferentes ordenamentos e realidades jurídicas.
- 3-D Mechanically Tunable Square Slot FSSPublication . Ferreira, David; Cuinas, Inigo; Caldeirinha, Rafael F. S.; Fernandes, TelmoWe introduce an innovative 3-D mechanically tunable frequency selective surface (FSS), which is inspired by the classical flat square slot FSS. The proposal improves the performance of classical 2-D FSS designs, and it also represents a novel method of achieving mechanical frequency tuning, despite other 3-D designs that consist of a collection of stacked 3-D layers exist. In our proposal, the rotation of an inner element provides tuning capability to the squared cell structure, consisting of metallic grids with a movable inner element. An aluminum prototype was built, which can be tuned from 2.4 to 4 GHz, and also compared its measured performance and numerical simulations. Some characteristics of the proposed structure are the rejection level at main polarization, up to 20 dB, and the maximum frequency sweep of approximately 50% of the fundamental frequency. The prototype showed a stable frequency response for angles of incidence up to 45°. Since results are in good agreement with simulations, we provide parametric equations to design 3-D structures at desired frequencies.
- 3D bioprinting of photocrosslinkable hydrogel constructsPublication . Brás Pereira, Rúben Filipe; Bartolo, PauloThree‐dimensional (3D) bioprinting comprises a group of biofabrication technologies for the additive manufacturing of 3D constructs by precisely printing biocompatible materials, cells and biochemicals in predesigned spatial positions. These technologies have been successfully applied to fabricate biodegradable 3D constructs with intricate architectures and heterogeneous composition, assuming a pivotal role in the field of tissue engineering. However, the full implementation of bioprinting strongly depends on the development of novel biomaterials exhibiting fast crosslinking schemes and appropriate printability, cell‐compatibility and biomechanical properties. Photocrosslinkable hydrogels are attractive materials for bioprinting as they provide fast polymerization under cell‐compatible conditions and exceptional spatiotemporal control over the gelation process. Photopolymerization can also be performed during the bioprinting to promote the instantaneous formation of hydrogel with high well‐defined architecture and structural stability. In this review paper, we summarize the most recent developments on bioprinting of photocrosslinkable biodegradable hydrogels for tissue engineering, focusing on the chemical modification strategies and the combination of photocrosslinking reactions with other gelation modalities.
- 3D deformations by means of monogenic functionsPublication . Ferreira, Milton; Morais, JoãoIn this paper, the authors compute the coefficient of quasiconformality for monogenic functions in an arbitrary ball of the Euclidean space $\mathbb{R}^3$. This quantification may be needed in applications but also appear to be of intrinsic interest. The main tool used is a 3D Fourier series development of monogenic functions in terms of a special set of solid spherical monogenics. Ultimately, we present some examples showing the applicability of our approach.