Percorrer por autor "Teixeira, Senhorinha F.C.F."
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- Advances in Microfluidic Systems and Numerical Modeling in Biomedical Applications: A ReviewPublication . Ferreira, Mariana; Carvalho, Violeta Meneses; Ribeiro, J.E.; Lima, Rui A.; Teixeira, Senhorinha F.C.F.; Pinho, DianaThe evolution in the biomedical engineering field boosts innovative technologies, with microfluidic systems standing out as transformative tools in disease diagnosis, treatment, and monitoring. Numerical simulation has emerged as a tool of increasing importance for better understanding and predicting fluid-flow behavior in microscale devices. This review explores fabrication techniques and common materials of microfluidic devices, focusing on soft lithography and additive manufacturing. Microfluidic systems applications, including nucleic acid amplification and protein synthesis, as well as point-of-care diagnostics, DNA analysis, cell cultures, and organ-on-a-chip models (e.g., lung-, brain-, liver-, and tumor-on-a-chip), are discussed. Recent studies have applied computational tools such as ANSYS Fluent 2024 software to numerically simulate the flow behavior. Outside of the study cases, this work reports fundamental aspects of microfluidic simulations, including fluid flow, mass transport, mixing, and diffusion, and highlights the emergent field of organ-on-a-chip simulations. Additionally, it takes into account the application of geometries to improve the mixing of samples, as well as surface wettability modification. In conclusion, the present review summarizes the most relevant contributions of microfluidic systems and their numerical modeling to biomedical engineering.
- Diagnosis methods for COVID-19: a systematic reviewPublication . Maia, Renata; Carvalho, Violeta Meneses; Faria, Bernardo; Miranda, Inês; Catarino, Susana; Teixeira, Senhorinha F.C.F.; Lima, Rui A.; Minas, Graça; Ribeiro, J.E.At the end of 2019, the coronavirus appeared and spread extremely rapidly, causing millions of infections and deaths worldwide, and becoming a global pandemic. For this reason, it became urgent and essential to find adequate tests for an accurate and fast diagnosis of this disease. In the present study, a systematic review was performed in order to provide an overview of the COVID-19 diagnosis methods and tests already available, as well as their evolution in recent months. For this purpose, the Science Direct, PubMed, and Scopus databases were used to collect the data and three authors independently screened the references, extracted the main information, and assessed the quality of the included studies. After the analysis of the collected data, 34 studies reporting new methods to diagnose COVID-19 were selected. Although RT-PCR is the gold-standard method for COVID-19 diagnosis, it cannot fulfill all the requirements of this pandemic, being limited by the need for highly specialized equipment and personnel to perform the assays, as well as the long time to get the test results. To fulfill the limitations of this method, other alternatives, including biological and imaging analysis methods, also became commonly reported. The comparison of the different diagnosis tests allowed to understand the importance and potential of combining different techniques, not only to improve diagnosis but also for a further understanding of the virus, the disease, and their implications in humans.
- Editorial for the special issue on micro/nanofluidic and lab-on-a-chip devices for biomedical applicationsPublication . Carvalho, Violeta Meneses; Teixeira, Senhorinha F.C.F.; Ribeiro, J.E.Micro/Nanofluidic and lab-on-a-chip devices have been increasingly used in biomedi- cal research [ 1]. Because of their adaptability, feasibility, and cost-efficiency, these devices can revolutionize the future of preclinical technologies. Furthermore, they allow insights into the performance and toxic effects of responsive drug delivery nanocarriers to be obtained, which consequently allow the shortcomings of two/three-dimensional static cultures and animal testing to be overcome and help to reduce drug development costs and time [ 2 –4 ]. With the constant advancements in biomedical technology, the development of enhanced microfluidic devices has accelerated, and numerous models have been reported. Given the multidisciplinary of this Special Issue (SI), papers on different subjects were published making a total of 14 contributions, 10 original research papers, and 4 review papers. The review paper of Ko et al. [ 1] provides a comprehensive overview of the significant advancements in engineered organ-on-a-chip research in a general way while in the review presented by Kanabekova and colleagues [2 ], a thorough analysis of microphysiological platforms used for modeling liver diseases can be found. To get a summary of the numerical models of microfluidic organ-on-a-chip devices developed in recent years, the review presented by Carvalho et al. [5 ] can be read. On the other hand, Maia et al. [6] report a systematic review of the diagnosis methods developed for COVID-19, providing an overview of the advancements made since the start of the pandemic. In the following, a brief summary of the research papers published in this SI will be pre- sented, with organs-on-a-chip, microfluidic devices for detection, and device optimization having been identified as the main topics.
- Fluid flow and structural numerical analysis of a cerebral aneurysm modelPublication . Souza, Maria Sabrina; Souza, Andrews Victor Almeida; Carvalho, Violeta Meneses; Teixeira, Senhorinha F.C.F.; Fernandes, Carla S.; Lima, Rui A.; Ribeiro, J.E.Intracranial aneurysms (IA) are dilations of the cerebral arteries and, in most cases, have no symptoms. However, it is a very serious pathology, with a high mortality rate after rupture. Several studies have been focused only on the hemodynamics of the flow within the IA. However, besides the effect of the flow, the development and rupture of the IA are also associated with a combination of other factors such as the wall mechanical behavior. Thus, the objective of this work was to analyze, in addition to the flow behavior, the biomechanical behavior of the aneurysm wall. For this, CFD simulations were performed for different Reynolds numbers (1, 100, 500 and 1000) and for two different rheological models (Newtonian and Carreau). Subsequently, the pressure values of the fluid simulations were exported to the structural simulations in order to qualitatively observe the deformations, strains, normal stresses and shear stress generated in the channel wall. For the structural simulations, a hyperelastic constitutive model (5-parameter Mooney–Rivlin) was used. The results show that with the increase in the Reynolds number (Re), the recirculation phenomenon is more pronounced, which is not seen for Re = 1. The higher the Re, the higher the strain, displacement, normal and shear stresses values.
- In vitro biomodels in stenotic arteries to perform blood analogues flow visualizations and measurements: a reviewPublication . Carvalho, Violeta Meneses; Maia, Inês; Souza, Andrews; Ribeiro, J.E.; Costa, Pedro; Puga, Hélder Fernandes; Teixeira, Senhorinha F.C.F.; Lima, Rui A.Cardiovascular diseases are one of the leading causes of death globally and the most common pathological process is atherosclerosis. Over the years, these cardiovascular complications have been extensively studied by applying in vivo, in vitro and numerical methods (in silico). In vivo studies represent more accurately the physiological conditions and provide the most realistic data. Nevertheless, these approaches are expensive, and it is complex to control several physiological variables. Hence, the continuous effort to find reliable alternative methods has been growing. In the last decades, numerical simulations have been widely used to assess the blood flow behavior in stenotic arteries and, consequently, providing insights into the cardiovascular disease condition, its progression and therapeutic optimization. However, it is necessary to ensure its accuracy and reliability by comparing the numerical simulations with clinical and experimental data. For this reason, with the progress of the in vitro flow measurement techniques and rapid prototyping, experimental investigation of hemodynamics has gained widespread attention. The present work reviews state-of-the-art in vitro macro-scale arterial stenotic biomodels for flow measurements, summarizing the different fabrication methods, blood analogues and highlighting advantages and limitations of the most used techniques.
- Micro/nanofluidic and lab-on-a-chip devices for biomedical applicationsPublication . Carvalho, Violeta Meneses; Teixeira, Senhorinha F.C.F.; Ribeiro, J.E.Micro/Nanofluidic and lab-on-a-chip devices have been increasingly used in biomedical research [1]. Because of their adaptability, feasibility, and cost-efficiency, these devices can revolutionize the future of preclinical technologies. Furthermore, they allow insights into the performance and toxic effects of responsive drug delivery nanocarriers to be obtained, which consequently allow the shortcomings of two/three-dimensional static cultures and animal testing to be overcome and help to reduce drug development costs and time [2–4]. With the constant advancements in biomedical technology, the development of enhanced microfluidic devices has accelerated, and numerous models have been reported. Given the multidisciplinary of this Special Issue (SI), papers on different subjects were published making a total of 14 contributions, 10 original research papers, and 4 review papers. The review paper of Ko et al. [1] provides a comprehensive overview of the significant advancements in engineered organ-on-a-chip research in a general way while in the review presented by Kanabekova and colleagues [2], a thorough analysis of microphysiological platforms used for modeling liver diseases can be found. To get a summary of the numerical models of microfluidic organ-on-a-chip devices developed in recent years, the review presented by Carvalho et al. [5] can be read. On the other hand, Maia et al. [6] report a systematic review of the diagnosis methods developed for COVID-19, providing an overview of the advancements made since the start of the pandemic. In the following, a brief summary of the research papers published in this SI will be presented, with organs-on-a-chip, microfluidic devices for detection, and device optimization having been identified as the main topics.
- Patente Nacional Nº 117823 - Máscara facial, métodos para obtenção e utilização da mesmaPublication . Machado, Lúcio Manuel Machado; Soares, Delfim Fernandes; Faria, Carlos Alberto Jorge Leite; Minas, Graça Maria Henriques; Lima, Rui A.; Freitas, José Torcato Oliveira; Ribeiro, J.E.; Machado, Lúcio Manuel Alves; Freitas, Pedro Gil Novais; Gonzalez Abelleira, Lisardo Antonio; Areal, Clarisse Fernandes; Vilarinho, Maria Cândida Lobo Guerra; Carvalho, Joana Maria Freitas; Ribeiro, André José Pereira; Souza, Andrews Victor Almeida de; Sousa, Paulo; Teixeira, Senhorinha F.C.F.A presente divulgação refere-se a uma máscara facial compreendendo uma porção alongada para cobrir a face de um utilizador do nariz ao queixo e bochechas, e duas alças de orelha ligadas à porção alongada para fixar a referida porção alongada à face, em que a porção alongada compreende um filme transparente de polidimetilsiloxano (1).
- Rheology of F620 solder paste and fluxPublication . Barbosa, Flavia V.; Teixeira, José C.F.; Teixeira, Senhorinha F.C.F.; Lima, Rui A.; Soares, Delfim; Pinho, DianaThe aim of this paper is to characterize the rheological properties of the flux media exposed to different levels of solicitation and to determine its influence on the rheology of the solder paste. The data obtained experimentally are fundamental for the development of numerical models that allow the simulation of the printing process of printed circuit boards (PCB). Design/methodology/approach – Rheological tests were performed using the Malvern rheometer Bohlin CVO. These experiments consist of the analysis of the viscosity, yield stress, thixotropy, elastic and viscous properties through oscillatory tests and the capacity to recover using a creeprecovery experiment. The results obtained from this rheological analysis are compared with the rheological properties of the solder paste F620. Findings – The results have shown that the flux is viscoelastic in nature and shear thinning. The viscosity does not decrease with increasing solicitations, except in the case where the flow is withdrawn directly from the bottle. Even if the solder paste shows a thixotropic behavior, this is not the case of the flux, meaning that this property is given by the metal particles. Furthermore, the oscillatory tests proved that the flux presents a dominant solid-like behavior, higher than the solder paste, meaning that the cohesive/tacky behavior of the solder paste is given by the flux. Research limitations/implications – To complement this work, printing tests are required. Originality/value – This work demonstrates the importance of the rheological characterization of the flux in order to understand its influence in the solder paste performance during the stencil printing process.