Search Results (516)

Modern aircraft increasingly utilizes highly integrated electronic equipment, driving continuously increasing heat dissipation demands. Vapor compression refrigeration systems demonstrate stronger alignment with future aircraft thermal management trends, leveraging their superior volumetric cooling capacity, high energy efficiency, and independence from engine bleed air. This paper reviews global research progress on aircraft vapor compression refrigeration systems, covering performance optimization, dynamic characteristics, control strategies, fault detection, and international development histories and typical applications. Analysis identifies emerging challenges under large-temperature-range cooling requirements, with comparative assessment establishing zeotropic mixture auto-cascade vapor compression refrigeration systems as the optimal forward-looking solution. Finally, recognizing current research gaps, we propose future research directions for onboard auto-cascade vapor compression refrigeration systems: optimizing refrigerant mixtures for flight conditions, achieving efficient gas-liquid separation during variable overloads and attitude conditions, and developing model predictive control with intelligent optimization to ensure reliability. Full article

As digital transformation progresses, schools are increasingly confronted with psychosocial challenges such as technostress, digital overload, and unequal participation in digital (learning) environments. This article investigates the conceptual relevance of digital well-being for school development, particularly in relation to social inequality. Despite growing attention, the term remains theoretically underdefined in educational research—a gap addressed through a theory-driven review. Drawing on a systematic search, 25 key studies were analyzed for their conceptual understanding and refinement of digital well-being, with a focus on educational relevance. Findings suggest that digital well-being constitutes a multidimensional state shaped by individual, media-related, and socio-structural factors. It emerges when individuals are able to successfully manage the demands of digital environments and is closely linked to digital inequality—particularly in terms of access, usage practices, and the resulting opportunities for participation and health promotion. Since the institutional role of schools has thus far received limited attention, this article shifts the focus toward schools as key arenas for negotiating digital norms and practices and calls for an equity-sensitive and health-conscious perspective on school development in the context of digitalization. In doing so, digital well-being is repositioned as a pedagogical cross-cutting issue that requires coordinated efforts across all levels of the education system, highlighting that equitable digital transformation in schools depends on a critical reflection of power asymmetries within society and educational institutions. The article concludes by advocating for the systematic integration of digital well-being into school development processes as a way to support inclusive digital participation and to foster a health-oriented digital school culture. Full article

Secondary iron overload exacerbates osteoporosis by elevating reactive oxygen species (ROS), which suppress osteoblast function and enhance osteoclast activity, disrupting bone remodeling. Reducing iron overload and oxidative stress may improve bone health. Epigallocatechin-3-gallate (EGCG), the main bioactive compound in green tea extract (GTE), is recognized for its antioxidant and iron-chelating properties. This study examined the effect of GTE on bone formation and mineralization in iron-overloaded human osteoblast-like MG-63 cells. An iron-overloaded model was established using ferric ammonium citrate (FAC), followed by treatment with GTE, deferiprone (DFP), or their combination. GTE significantly reduced intracellular iron, ROS levels, and lipid peroxidation while upregulating the osteogenic marker BGLAP, the anti-resorptive marker OPG, and osteogenic mineralization, indicating restored bone health. These results suggest that EGCG-containing GTE mitigates iron-induced oxidative stress and promotes osteogenesis, highlighting its potential as a natural therapeutic supplement for managing iron-overload-associated osteoporosis. Full article

Hypertensive left ventricular hypertrophy (LVH) is an ominous cardiovascular sequel to chronic hypertension, marked by structural and functional alterations in the heart. Identified as a significant risk factor for adverse cardiovascular outcomes, LVH is typically detected through echocardiography and is characterized by pathological thickening of the left ventricular wall. This hypertrophy results from chronic pressure overload (increased afterload), leading to concentric remodelling, or from increased diastolic filling (preload), contributing to eccentric changes. Apoptosis, a regulated process of cell death, plays a critical role in the pathogenesis of LVH by contributing to cardiomyocyte loss and subsequent cardiac dysfunction. Given the substantial clinical implications of LVH for cardiovascular health, this review critically examines the role of cardiomyocyte apoptosis in its disease progression, evaluates the impact of pharmacological interventions, and highlights the necessity of a comprehensive, multifaceted treatment approach for the prevention and management of hypertensive LVH. Finally, we address the health disparities associated with LVH, with particular attention to the disproportionate burden faced by African Americans and other Black communities, as this remains a key priority in advancing equity in cardiovascular care. Full article

Background: The effective use of electronic health records (EHRs) is an essential clinical skill, but medical schools have traditionally provided limited systematic teaching on the topic. Inefficient use of EHRs results in delays in diagnosis, fragmented care, and clinician burnout. This study investigates the impact on medical students’ confidence, efficiency, and proficiency in extracting clinically pertinent information from patient records following an organised EHR teaching programme. Methods: This observational cohort involved 60 final-year medical students from three London medical schools. Participants received a structured three-phase intervention involving an introductory workshop, case-based hands-on practice, and guided reflection on EHR navigation habits. Pre- and post-intervention testing involved mixed-method surveys, simulated case tasks, and faculty-assessed data retrieval exercises to measure changes in students’ confidence, efficiency, and ability to synthesise patient information. Quantitative data were analysed using paired t-tests, while qualitative reflections were theme-analysed to identify shifts in clinical reasoning. Results: All 60 students successfully finished the intervention and assessments. Pre-intervention, only 28% students reported feeling confident in using EHRs effectively, with a confidence rating of 3.0. Post-intervention, 87% reported confidence with a rating of 4.5 (p < 0.01). Efficiency in the recovery of critical patient information improved from 3.2 to 4.6 (p < 0.01). Students also demonstrated enhanced awareness regarding system-related issues, such as information overload and fragmented documentation, and provided recommendations on enhancing data synthesis for clinical decision making. Conclusions: This study emphasises the value of structured EHR instruction in enhancing the confidence and proficiency of medical students in using electronic records. The integration of structured EHR education to medical curricula can better prepare future physicians in managing information overload, improve diagnostic accuracy, and enhance the quality of patient care. Future research should explore the long-term impact of structured EHR training on clinical performance, diagnostic accuracy, and patient outcomes during real-world clinical placements and postgraduate training. Full article

Cardiac iron overload is a rare but important adverse consequence of systemic iron overload, marked by the abnormal accumulation of iron in the myocardium. It is most typically caused by hereditary hemochromatosis (mutations in the HFE gene) or secondary iron overload conditions, such as transfusion-dependent anemias. Excess iron in the myocardium causes oxidative stress, cardiomyocyte damage, and progressive fibrosis, ultimately leading to cardiomyopathy. Clinical manifestations are diverse and may include heart failure, arrhythmias, and restrictive or dilated cardiomyopathy. Given the worsened prognosis with cardiac involvement, timely diagnosis and management are essential to improve clinical outcomes. This review provides a contemporary overview of the cardiovascular complications associated with iron overload, including clinical manifestations, diagnostic approaches, and treatment options. Full article

Presenteeism, characterized by going to work sick, has become increasingly prevalent in nursing, a profession with high social and interpersonal demands. It is associated with a deterioration of the health of nurses, a reduction in the excellence of care, and a decrease in safety for users. Burnout is related to stress and mental overload and is characterized by exhaustion and fatigue. Objective: To map the evidence on the relationship between presenteeism and burnout in nurses. Methods: A literature review was carried out using the EBSCOHost Research search engine in various databases. Eight studies were selected and analyzed. Results: The studies identify a consistent relationship between burnout and presenteeism in nurses. Emotional exhaustion, resulting from burnout, can lead nurses to go to work despite being ill, due to a sense of responsibility, ethical duty, or organizational pressures. Most studies are cross-sectional, which limits the ability to establish causal relationships and identify specific interventions to reduce burnout-related presenteeism in nursing. Conclusions: It is essential to invest in health management policies for nurses to reduce burnout and minimize the consequences of presenteeism. Full article

Wilson’s disease is a rare autosomal recessive disorder of copper metabolism characterized by excessive copper accumulation in the liver, brain, and other tissues. This paper provides an overview of the primary pharmacological agents used in its treatment, including penicillamine, trientine, tetrathiomolybdate, and zinc. Their mechanisms of action, therapeutic applications, and side-effect profiles are examined, emphasizing how each agent helps reduce copper overload. Additionally, brief information is given on novel therapies such as gene therapy and artificial intelligence applications. Furthermore, information about the structural and chemical properties of these compounds is provided, highlighting the molecular features that enable them to chelate copper or reduce its intestinal absorption. By integrating pathophysiological insights with chemical and mechanistic perspectives, this paper offers a comprehensive review of existing treatment strategies for Wilson’s disease and stresses the importance of careful, patient-specific management to optimize long-term outcomes. Full article

Tricuspid regurgitation (TR) represents a significant, often silently progressing, valvular heart disease with historically suboptimal management due to perceived high surgical risks. Transcatheter tricuspid valve interventions (TTVI) offer a promising, less invasive therapeutic avenue. Central to the success of TTVI is Right Ventricular Reverse Remodelling (RVRR), defined as an improvement in RV structure and function, which strongly correlates with enhanced patient survival. The right ventricle (RV) undergoes complex multi-scale biomechanical maladaptations, progressing from adaptive concentric to maladaptive eccentric hypertrophy, coupled with increased stiffness and fibrosis. Molecular drivers of this pathology include early failure of antioxidant defenses, metabolic shifts towards glycolysis, and dysregulation of microRNAs. Accurate RV function assessment necessitates advanced imaging modalities like 3D echocardiography, Cardiac Magnetic Resonance Imaging (CMR), and Computed Tomography (CT), along with strain analysis. Following TTVI, RVRR typically manifests as a biphasic reduction in RV volume overload, improved myocardial strain, and enhanced RV-pulmonary arterial coupling. Emerging molecular biomarkers alongside advanced imaging-derived biomechanical markers like CT-based 3D-TAPSE and RV longitudinal strain, are proving valuable. Artificial intelligence (AI) and machine learning (ML) are transforming prognostication by integrating diverse clinical, laboratory, and multi-modal imaging data, enabling unprecedented precision in risk stratification and optimizing TTVI strategies. Full article

Efficient decentralized power management is crucial for enhancing the reliability, resilience, responsiveness, and sustainability of secondary power distribution systems, thereby preventing major power outages and providing rapid responses. However, existing secondary power distribution networks are prone to failures, thus compromising their operational trustworthiness and efficiency. This work proposes an intelligent, decentralized control system with distributed processing capabilities. The proposed system is designed to automate fault detection and rectification along with optimized power management at secondary distribution nodes. The system enables rapid fault detection (line-to-line, line-to-ground, and overload) and initiates a fault-based response to isolate the load through controlled relays. Additionally, an intelligent power management system automatically rectifies surge faults (short-lived faults) and reports non-surge faults (persistent faults) to the control center. It continuously updates the status of real-time power parameters to the database using a Global System for Mobile Communications (GSM)-based communication system with a frequency of 60 s per sample for power management. The Proteus-based simulation and a scaled-down model validate the efficiency and supremacy of the proposed system over the existing control system for power distribution nodes. The results demonstrate that our model detects critical faults and initiates the response within 100 and 200 milliseconds, respectively. Surge faults are automatically rectified within 90 s, while non-surge faults are reported to the database after 90 s. This approach significantly reduces downtime, enables energy accountability, and supports sustainable energy management through a decentralized and distributed control system. Full article

Increasing climate change requires cities to adapt to changing weather conditions. New elements for decentralized stormwater management must be installed to protect the sewer system from overloading during heavy rainfall events and to keep water in the city for irrigation use. A pilot project was implemented in Leipzig in 2020, in which infiltration tree trench systems with three different designs were installed and equipped with measuring technology during a road renovation project. The catchment areas of these three tree trenches are between 215 and 300 m² each. In two of the systems, water retention was included to supply the tree with water during drought periods. The retention elements are sealed with clay in tree trench TT1 and bentonite in tree trench TT3. For tree trench TT2, no retention capacity was provided. This article presents the design, construction, and scientific monitoring of the three tree infiltration trenches. The conclusions after four years of operation from the perspective of two departments of the City of Leipzig are summarized. The tree trench TT1 with the clay pan for water storage shows the best performance in terms of water retention and tree fitness. For the next generation of such infiltration systems, improvements in the design of the street runoff inlets and the surface of the tree trench system’s interior are discussed. Full article

Background: Acute heart failure (AHF) is a major cause of hospitalizations, posing significant challenges to healthcare systems. Despite advancements in management, the rate of poor outcomes remains high globally, emphasizing the need for timely interventions. This study aimed to identify early admission-based factors predictive of poor outcomes in hospitalized AHF patients, in order to contribute to early risk stratification and optimize patient care. Methods: This retrospective single-center study analyzed routine data of adult patients hospitalized for AHF at a public university teaching hospital in Switzerland. Outcomes included in-hospital death, intensive care (ICU) treatment, and length of hospital stay (LOHS). Potential predictors were limited to routine parameters, readily available at admission. Missing predictor data was imputed and predictors were identified by means of multivariable regression analysis. Results: Data of 638 patients (median age 84 years, range 45–101 years, 50% female) were included in the study. In-hospital mortality was 7.1%, ICU admission rate 3.8%, and median LOHS was 8 days (IQR 5–12). Systolic blood pressure ≤ 100 mmHg (Odds ratio (OR) 3.8, p = 0.009), peripheral oxygen saturation ≤ 90% or oxygen supplementation (OR 5.9, p < 0.001), and peripheral edema (OR 2.7, p = 0.044) at hospital admission were identified as predictors of in-hospital death. Furthermore, a stroke or transient ischemic attack in the patient’s history (OR 3.2, p = 0.023) was associated with in-hospital death. ICU admission was associated with oxygen saturation ≤ 90% or oxygen supplementation (OR 22.9, p < 0.001). Factors linked to longer LOHS included oxygen saturation ≤ 90% or oxygen supplementation (IRR 1.2, p < 0.001), recent weight gain (IRR 1.1, p = 0.028), and concomitant chronic kidney disease (IRR 1.2, p < 0.001). Conclusions: This study validated established predictors of AHF outcomes in a Swiss cohort, highlighting the predictive value of poor perfusion status, fluid overload, and comorbidities such as chronic kidney disease. The identified predictors imply potential for developing tools to improve rapid treatment decisions. Future research should focus on the prospective external validation of the identified predictors and the design and validation of risk scores, incorporating these parameters to optimize early interventions and reduce adverse outcomes in AHF. Full article

Motorbike taxis are widely used in Yaoundé and Douala, despite their association with heightened accident risks and relatively high fares. This research combines qualitative methods, including 38 semi-structured interviews and direct field observations, with a quantitative survey of 280 motorbike taxi passengers (customers). It employs a dynamic risk approach to analyse both the factors motivating individuals to choose motorbike taxis and the strategies adopted by drivers and passengers to mitigate and prevent accidents. The findings reveal that speed, cost-effectiveness, and the limited accessibility of certain neighbourhoods to other transport options are key factors driving regular motorbike taxi use. Moreover, strategies for managing accident risks include regulating passenger positions based on gender, perceived age, or physical stature; invoking deities for protection; and passengers’ verbal interactions with drivers to ensure safer behaviour. This research also explores how overloading, a collectively tolerated deviance, is managed to avoid or minimize the impact of accidents. By addressing both risk acceptance and prevention strategies, this study provides new insights into passengers’ social perceptions, which are often overlooked in motorbike taxi research. It expands the understanding of motorbike taxi use in urban Global South transport contexts, particularly in terms of users’ risk management behaviours. Full article

In addition to architecture and infrastructure, urban outdoor advertising also shapes urban visual identity, serving as a prominent carrier of public information and visual stimuli. However, excessive or poorly designed advertisements disrupt the cityscape and contribute to visual pollution and cognitive overload. Leveraging computer-based eye tracking, this study examines the visual and cognitive effects of outdoor advertising designs within urban contexts. Key eye-tracking metrics, including total fixation duration, fixation count, time to first fixation, and first fixation duration, are measured to analyze the influence of various variables on visual attention and user experience, such as color contrast, text complexity, information hierarchy, and spatial layout. The findings reveal that high-contrast, text-heavy designs hinder visual flow and increase mental effort, while visually balanced layouts improve legibility and reduce cognitive burden. These results offer actionable insights for optimizing urban visual identity and enhancing the clarity, comfort, and coherence of outdoor advertising. By integrating perceptual data into urban design strategies, this research provides a data-driven approach to smarter, more human-centered advertising management and urban aesthetic governance. Full article

Background/Objectives: This work aims to assess the evolution in the management of Staphylococcus aureus bacteremia (SAB) and the impact of the COVID-19 pandemic on it. SAB is associated with high morbidity and mortality, requiring structured management strategies. The COVID-19 pandemic led to major changes in hospital workflows, potentially affecting the quality of SAB care. Methods: We conducted a retrospective per-protocol analysis of SAB episodes at Costa del Sol University Hospital (Marbella, Spain) across three periods: pre-pandemic, pandemic, and post-pandemic. Patients with early mortality or early transfer were excluded. Clinical variables, adherence to recommended management bundles, and outcomes were compared. Demographic characteristics were similar across the analyzed periods. Results: The incidence of SAB increased over time, with a notable rise post-pandemic. Key management indicators such as the identification of infection source and appropriate antibiotic therapy showed adherence rates of above 90%, while echocardiography exhibited an adherence rate of above 75% throughout the study. Adherence to the full management bundle was suboptimal, with no significant differences between periods. However, an appropriate treatment duration significantly improved in the post-pandemic group (p = 0.038). Mortality at 14 and 30 days was highest during the pandemic period (10.3% and 17.6%, respectively), although differences were not statistically significant. Complications and mortality were more frequent in patients with complete adherence to the bundle (p = 0.031). Conclusions: Despite stable or improved adherence to certain SAB management measures during the pandemic, mortality and complication rates did not significantly decrease, likely reflecting increased patient severity or healthcare system overload. These findings highlight the need for sustained, multidisciplinary, bedside-based approaches to SAB care, even during public health emergencies. Further research is needed to explore modifiable factors and enhance adherence to evidence-based recommendations. Full article