As comunicações por satélite são fulcrais no mundo moderno, principalmente para a geolocalização e navegação, que são essenciais no posicionamento de veículos, incluindo na indústria da condução autónoma. Para garantir a segurança, eficiência e mais, os veículos autónomos necessitam de comunicações por satélite precisas e fiáveis, apoiadas por sistemas complexos que incluem antenas de polarização circular. Por isso, estas antenas devem garantir um bom sinal mesmo em condições onde existem várias reflexões, interferências ou bloqueio do sinal. As antenas definidas por software (SDAs), que têm como elemento central um agregado de antenas, podem ajudar a reduzir estes erros. O uso de antenas de dimensões reduzidas é, por isso, importante para a melhor integração no agregado, sendo por isso a miniaturização um aspeto crucial no seu design. Este trabalho apresenta uma análise detalhada de técnicas de desenho e miniaturização de antenas GNSS. São destacados os compromissos envolvidos neste processo, tais como o equilíbrio entre baixa complexidade, simetria e designs circulares, que otimizam a baixa variação do centro de fase, e maior largura do feixe de axial ratio, ou mesmo compromissos em largura de banda, ganho e desempenho geral durante a miniaturização, usando estratégias como braços de antena dobrados, meandros, fendas, elementos parasitas e mais. Durante o decorrer deste trabalho foram desenvolvidos dois designs de antenas miniaturizadas de polarização circular, sendo uma delas fabricada para ser caracterizada. Esta apresenta forma de trevo, com uma área de 0.34λ0 x 0.34λ0, ranhuras circulares, baixa variação do centro de fase, ampla largura de feixe de axial ratio, elevado ganho em polarização de mão direita, e forte rejeição de polarização cruzada. Posteriormente, esta antena é utilizada num agregado quadrado de 4x4, com espaçamento de 0.37λ0 entre elementos. Este permite uma forte rejeição de polarização cruzada, elevada diretividade, baixos níveis de lóbulos secundários e um axial ratio abaixo de 3 dB, em quatro direções. A orientação e posicionamento das antenas garante uma ampla largura de banda de axial ratio. É também mais fácil de produzir em massa, comparando com um agregado de antenas comercialmente disponíveis. O design inovador da antena GNSS miniaturizada apresentado neste trabalho possibilita a sua integração num agregado de uma SDA, através do qual se pode obter uma melhor precisão do posicionamento para veículos autónomos em várias condições ambientais e na presença de interferências. Através disto, a segurança e fiabilidade da ligação GNSS está salvaguardada, permitindo que a condução autónoma seja uma realidade cada vez mais próxima.

This paper presents a new miniaturized patch antenna design for GNSS applications with low phase center variation and high circular polarization purity. The phase center variation values of this antenna enable positioning performance to be equal when compared to bigger state of the art commercial antennas. It is found that the circular features as well as a small asymmetry caused by circular slot pairs, perpendicular to each other, can generate the wanted circular polarization results while maintaining the antenna compact. Anechoic chamber measurements validate the simulation results, showing return loss and axial ratio bandwidths of 3.42% and 0.83%, respectively, alongside wide axial ratio beamwidth of up to 184◦ (ϕ= 0◦), boresight cross polarization rejection of 19.2 dB and low phase center variation under 1.5◦ (θ= –70◦ to θ= 70◦). These results, specially phase center variation, in relation to the antenna dimensions, are an improvement when compared to a vast number of miniaturized patch antennas available in the literature and commercially The final overall antenna dimensions, including the ground plane, are 0.34λ0 x 0.34λ0 x 0.016λ0 where λ0 corresponds to the antenna’s working frequency in free space (1.575 GHz).

In recent decades, microelectronics advancements have miniaturized endoscopic systems, creating compact devices with enhanced performance. Current commercial endoscopes, however, still struggle to access delicate anatomical structures. This paper presents an ultracompact endoscope comprising a tip-mounted CMOS image sensor (CIS) and a single μLED, achieving a diameter of 1.8 mm, suitable for ultra-narrow human cavities. The optical system achieved a correlated color temperature (CCT) of 10,343 K and a color rendering index (CRI) of 73.6, which aids lesion detection. It can resolve features down to 20 μm with a diagonal FOV of 115.0° ± 2.4°, making it excellent for imaging and diagnosing previously inaccessible diseases in human organs. Ex-vivo validation using porcine reproductive tract tissue confirmed that the system acquires images with the morphological detail required to distinguish the main anatomical regions.

Cardiovascular Disease (CVD) remains the leading cause of morbidity and mortality worldwide. Despite significant advances in diagnosis and treatment, the global burden of CVD remains high, underscoring the crucial need for more effective and comprehensive prevention strategies. This narrative overview aims to critically evaluate the current pillars of cardiovascular prevention, identify the gaps in approaches and outline promising future directions. Challenges and barriers in lifestyle adherence and pharmacological management are addressed, while the increasing role of non-traditional and emerging risk factors is discussed. Future directions include maximizing the value of digital health to improve patient engagement and adherence, adopting precision medicine to refine risk stratification and implementing public health policies for population-level interventions. The optimization of cardiovascular prevention requires a multi-level approach that integrates clinical strategies with personalized solutions and environmental policies to ultimately reduce the global impact of CVD.

Cardiovascular Disease (CVD) remains the leading cause of morbidity and mortality worldwide. Despite significant advances in diagnosis and treatment, the global burden of CVD remains high, underscoring the crucial need for more effective and comprehensive prevention strategies. This narrative overview aims to critically evaluate the current pillars of cardiovascular prevention, identify the gaps in approaches and outline promising future directions. Challenges and barriers in lifestyle adherence and pharmacological management are addressed, while the increasing role of non-traditional and emerging risk factors is discussed. Future directions include maximizing the value of digital health to improve patient engagement and adherence, adopting precision medicine to refine risk stratification and implementing public health policies for population-level interventions. The optimization of cardiovascular prevention requires a multi-level approach that integrates clinical strategies with personalized solutions and environmental policies to ultimately reduce the global impact of CVD.

Cardiopulmonary exercise testing (CPET) provides a noninvasive and integrated assessment of the response of the respiratory, cardiovascular, and musculoskeletal systems to exercise. This information improves the diagnosis, risk stratification, and therapeutic management of several clinical conditions. Additionally, CPET is the gold standard test for cardiorespiratory fitness quantification and exercise prescription, both in patients with cardiopulmonary disease undergoing cardiac or pulmonary rehabilitation programs and in healthy individuals, such as high-level athletes. In this setting, the relevance of practical knowledge about this exam is useful and of interest to several medical specialties other than cardiology. However, despite its multiple established advantages, CPET remains underused. This article aims to increase awareness of the value of CPET in clinical practice and to inform clinicians about its main indications, applications, and basic interpretation.

Cardiopulmonary exercise testing (CPET) provides a noninvasive and integrated assessment of the response of the respiratory, cardiovascular, and musculoskeletal systems to exercise. This information improves the diagnosis, risk stratification, and therapeutic management of several clinical conditions. Additionally, CPET is the gold standard test for cardiorespiratory fitness quantification and exercise prescription, both in patients with cardiopulmonary disease undergoing cardiac or pulmonary rehabilitation programs and in healthy individuals, such as high-level athletes. In this setting, the relevance of practical knowledge about this exam is useful and of interest to several medical specialties other than cardiology. However, despite its multiple established advantages, CPET remains underused. This article aims to increase awareness of the value of CPET in clinical practice and to inform clinicians about its main indications, applications, and basic interpretation.

Numa época marcada pela revolução tecnológica, são cada vez mais os casos em que a tecnologia ganha mais notoriedade nos vários âmbitos empresariais. Assim sendo, e no âmbito da unidade curricular de Sistemas de Informação, da licenciatura de Gestão Hoteleira (ano letivo de 2011/2012), quisemos conciliar esta vertente com a hoteleira, ou seja, iremos demonstrar e analisar criticamente o rumo que a restauração irá tomar em termos de novas tecnologias, e também todos os seus aspetos positivos e negativos. Nesta discussão procurar-se-á dar ênfase à interação entre o cliente e as iguarias, através da vertente tecnológica, como por exemplo, os menus interativos, que contêm imagens das iguarias, onde é possível efetuar os pedidos através desse mesmo menu; as plataformas da internet que permitem fazer reservas em restaurantes; e também verificar algumas inovações tecnológicas a que o consumidor pode ter acesso quando se desloca a um estabelecimento de restauração. Concluindo, pretendemos auferir a pertinência do impacto do uso dos sistemas de informação na restauração.

Introduction Assessment of the electrocardiogram (ECG) in athletes remains controversial, with lack of standardization and difficulty in applying specific criteria in its interpretation. The purpose of this study was to assess variability in the interpretation of the ECG in athletes. Methods Twenty ECGs of competitive athletes were assessed by cardiologists and cardiology residents, 11 of them normal or with isolated physiological changes and nine pathological. Each ECG was classified as normal/physiological or pathological, with or without the use of specific interpretation criteria. Results The study presents responses from 58 physicians, 42 (72.4%) of them cardiologists. Sixteen (27.6%) physicians reported that they regularly assessed athletes and 32 (55.2%) did not use specific ECG interpretation criteria, of which the Seattle criteria were the most commonly used (n=13). Each physician interpreted 15±2 ECGs correctly, corresponding to 74% of the total number of ECGs (variation: 45%‐100%). Interpretation of pathological ECGs was correct in 68% (variation: 22%‐100%) and of normal/physiological in 79% (variation: 55%‐100%). There was no significant difference in interpretation between cardiologists and residents (74±10% vs. 75±10%; p=0.724) or between those who regularly assessed athletes and those who did not (77±12% vs. 73±9%; p=0.286), but there was a trend for a higher rate of correct interpretation using specific criteria (77±10% vs. 72±10%; p=0.092). The reproducibility of the study was excellent (intraclass correlation coefficient=0.972; p<0.001). Conclusions A quarter of the ECGs were not correctly assessed and variability in interpretation was high. The use of specific criteria can improve the accuracy of interpretation of athletes’ ECGs, which is an important part of pre‐competitive screening, but one that is underused.

Identifying the distribution and levels of pesticides in ambient air can contribute to a better knowledge of the risk associated with these compounds to human health. Taking into account the necessity of efficiently measuring pesticides in this matrix, this article briefly discusses the methods employed, including both active and passive air sampling, pesticides analysis, as well as the procedures that have been implemented for method validation. Although analytical efforts to obtain reliable results have been demonstrated in the literature, further attempts are required to improve the sampling procedures and analytical methods for determining pesticides in ambient air.