Powder-Based Additive Manufacturing of Ti₂AlNb Alloys: A Review of Processes, Microstructure and Mechanical Properties

Ti₂AlNb alloy, a new generation of low-density titanium aluminide intermetallic compound, possesses excellent high-temperature strength, creep resistance, and moderate density, making it a promising candidate for high-temperature aerospace structural components. Powder-based additive manufacturing technology provides an effective approach for fabricating high-performance Ti₂AlNb components, featuring high design freedom, efficient forming, and a controllable microstructure. This paper systematically reviews the research progress of powder-based additive manufacturing of Ti₂AlNb alloys, focusing on three mainstream powder-based processes, including Selective Laser Melting (SLM), Selective Electron Beam Melting (SEBM), and Direct Laser Deposition (DLD). The regulation effect of the extreme non-equilibrium thermal cycle during powder-based additive manufacturing on the alloy microstructure is analyzed, and the correlation between process parameters and mechanical properties of components is summarized. Meanwhile, the key challenges in this field are identified, such as the difficulty in completely eliminating typical forming defects, insufficient precision of microstructure regulation, and a lack of theoretical guidance for process optimization. Finally, combined with technological development trends, future research directions are prospected from the aspects of defect control, microstructure, and mechanical property regulation, as well as engineering application.

Kv1.5 Inhibition in Atrial Fibrillation: Molecular Mechanisms, Translational Challenges, and Implications for Equitable Rhythm Control

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a growing source of cardiovascular morbidity, stroke, heart failure, and death. Current pharmacologic rhythm-control strategies rely predominantly on antiarrhythmic agents with significant ventricular proarrhythmia risk and systemic toxicity, limiting their use in medically complex and underserved patient populations. The Kv1.5 channel, encoded by KCNA5, generates the atrial-selective ultrarapid delayed rectifier current (I_Kur) and has long been considered a promising target for safer rhythm control. This review focuses on the molecular biology of Kv1.5, including its regulation by auxiliary Kvβ1.2 subunits, redox signaling, oxidative stress, and extra-atrial vascular roles, and examines the preclinical and clinical evidence for Kv1.5-targeted therapy. We analyzed why selective I_Kur inhibitors, including XEN-D0103 and MK-0448, have failed to translate into effective antiarrhythmic therapy, with particular attention to the role of atrial electrical remodeling and reduced I_Kur density in established AF. We also review the limitations of existing class III and class Ic antiarrhythmic agents and discuss how genetic variation in KCNA5 across ethnic populations may inform more precise and equitable approaches to rhythm control. Together, these findings highlight the promise of Kv1.5 as an atrial-selective target and the major barriers limiting its clinical translation in AF.

Electrospun Scaffolds for Spinal Cord Injury Repair: Mechanisms, Strategies, and Advances

Spinal cord injury (SCI) is a devastating and irreversible damage to the central nervous system that can result in permanent disability or even death. Electrospinning technology, as a specialized fiber preparation method, possesses unique advantages such as high porosity, adjustable pore size, and an extremely high surface area-to-volume ratio. Despite the widespread attention this technology has garnered for its potential application in the treatment of SCI, there is still a lack of comprehensive and up-to-date reviews in the existing literature, and specific clinical treatment guidelines are also scarce. As a result, researchers and clinicians lack targeted guidance for practical implementation. To address this gap, the present article systematically summarizes the mechanisms by which electrospun scaffolds facilitate SCI repair and their current therapeutic applications. First, this review provides an in-depth analysis of the five core mechanisms underlying electrospinning therapy for SCI, including extracellular matrix (ECM) mimicry, axonal-extension guidance, multimodal signal regulation, drug loading and sustained release, and physical support and protection. Next, this review examines how key electrospinning parameters (fiber diameter, alignment, surface chemistry, biodegradation rate, and nanomorphology) influence these therapeutic mechanisms. Finally, this review explores the state-of-the-art applications of electrospun scaffolds in SCI treatment, including purely structural conduits, biochemical functionalization (drug loading and controlled release, immunomodulation and anti-inflammation, and coaxial electrospinning), and multi-component composite materials (hydrogel–electrospun hybrids, cell- and growth-factor co-delivery systems, and cell electrospinning).

Striking Surge in Lung Cancer Incidence in Children of Early Life

Lung cancer ranks first in mortality and the third in total cancer cases diagnosed in the US. The epidemiological trends may vary among different age groups, while the dynamics of risk factors evolve as well. We aim to carefully characterize trends of lung cancer among different age groups in the past two decades, by accessing the Surveillance, Epidemiology, and End Results (SEER) datasets from the National Cancer Institute (NCI), and to delineate possible root causes. The SEER datasets were obtained from NCI. Data on environmental risk factors were acquired from the Environmental Protection Agency and the United States Geological Survey. The tobacco consumption data were sourced from the Centers for Disease Control and Prevention. Trends were examined statistically with the Mann-Kendall algorithm. The incidence rate of lung cancer in the <15 age group has been rising in the past two decades, most strikingly among infants in the 0 age group (at birth to less than 1 year old). These findings were unique for lung cancer. The usage of e-Cigarettes among pregnant women increased, while the potential influence of other known risk factors was on the decline. A shrinkage of the infant population and a higher rate of pregnancy loss were observed during the same timespan. A striking rise in lung cancer incidence among infants has been identified that is opposite to the declining trend in the overall population, which might be related to increased e-Cigarette use in pregnant women. Urgent further investigation is warranted to safeguard the newborn population from being continuously affected potentially by lung cancer.

Driftless Area Streams in Karstic Agricultural Watersheds: Best Management Practices, Biotic Integrity, and Environmental Stressors

To protect streams in agricultural watersheds, best management practices (BMPs) are implemented to reduce or prevent contaminated runoff from reaching surface waters. Over the course of three growing seasons (2000–2002), this study assessed physical, chemical, and biological indicators of water quality at 13 total stream sites in two agricultural watersheds (Garvin Brook, Whitewater River) in southeastern Minnesota USA, where BMPs have been used for over 50 years prior to the study period. Some sites in both watersheds exhibited impaired water quality due to high turbidities, high levels of total suspended solids (TSS) and fecal coliform bacteria, and low fish and benthic macroinvertebrate biotic integrities. Non-metric multi-dimensional scaling of water quality indicators and principal components analysis of fish and invertebrate communities highlighted varying degrees of differences between watersheds. On average, Garvin watershed sites exhibited better water quality during 2000–2002 than sites in the Whitewater watershed, likely because more headwater reaches were surveyed in Garvin Brook. A fish community index biotic integrity (IBI) was significantly negatively correlated with turbidities, TSS, and fecal coliform bacteria levels, but the benthic macroinvertebrate community IBI was not correlated to any water quality indicator or to the fish IBI. More recent studies in these watersheds and current impaired waters listings continue to indicate significant and ongoing water quality issues, so continued water quality monitoring is needed in these two watersheds to highlight and prioritize problematic subwatersheds for future conservation efforts to reduce or prevent agriculture-related runoff from reaching the stream networks.

Utility of Ambulatory Non-Invasive Rhythm Monitoring in Pregnant Patients with Palpitations and Structurally Normal Hearts

Ambulatory Cardiac Monitoring (ACM) is often used to evaluate pregnant patients with palpitations without structural heart disease; however, the diagnostic yield is not well defined. This single-center retrospective cohort study included pregnant patients without structural heart disease evaluated in a tertiary care cardio-obstetrics clinic between June 2023 and June 2024. The primary outcome was the detection of a clinically significant arrhythmia. Secondary outcomes included symptom–rhythm correlation and adverse maternal cardiac, obstetric, and fetal outcomes. Out of 124 patients identified, 49 (40%) completed ACM. Two patients had symptomatic clinically significant arrhythmias detected on ACM, including non-sustained ventricular tachycardia that did not alter management (n = 1), and symptomatic supraventricular tachycardia (SVT) resulting in medical therapy (n = 1). Palpitations occurred during monitoring in 35 of the 49 remaining monitored patients; of those, symptoms correlated with non-significant arrhythmias (premature atrial and ventricular contractions) in 11 (31%). No adverse cardiac events occurred in the remaining patients. Obstetric and fetal outcomes did not differ between monitored and unmonitored patients. In this small single center study, ACM in pregnant patients without structural heart disease has a low diagnostic yield. These findings could be used in shared decision-making for pregnant patients being evaluated for palpitations.

Foreword to the Commemorative Issue Honoring Professor David Ollis

Evaluation of University Students’ Perspectives on the Relationship Between Sustainability and Energy

Narrowing the gap between energy demand and supply, while improving the efficiency of energy consumption, has become one of the central sustainability challenges addressed in global policy agendas. Implementing energy management systems in public institutions and organizations is important for achieving this balance. University campuses can be considered small cities, as they serve as living spaces for students. Therefore, since establishing an energy management system is a long-term process, its timely implementation and the creation of an effective system can only be achieved if the students actively using the campus understand and take ownership of the concept. This study explores the role of students as active participants in campus energy management, with a particular focus on integrating the ISO 50001 Energy Management System into higher education environments. A mixed-methods approach was used at Ankara Yıldırım Beyazıt University’s (AYBU) Etlik Campus, combining longitudinal building energy consumption data (2019–2023) with a face-to-face survey of 201 students from nine departments within the Faculty of Engineering and Natural Sciences. The survey assessed students’ knowledge, attitudes, and willingness to participate in energy efficiency and sustainability initiatives. The findings suggest that while students are generally aware of sustainability concepts, their technical familiarity with standards such as ISO 50001 and units such as ton of oil equivalent (TOE) remains limited. Notably, Energy Systems Engineering (ESE) students tended to report higher awareness and stronger support for forming volunteer, student-led energy management units. Based on the findings, student-led energy management units may serve as a participatory mechanism to improve energy-data transparency, strengthen operational energy literacy, and support sustainability-oriented campus practices. This approach offers a repeatable framework for higher education institutions seeking to align operational energy performance with student-led sustainability actions.

Industry 4.0 Technologies as Drivers of Innovation in the Automotive Industry: Experiences of China and the United States

Industry 4.0 technologies represent one of the key drivers of the contemporary transformation of the automotive industry, with manufacturing digitalization, advanced automation, and robotics significantly influencing the sector’s innovation capacity and global competitiveness. This paper analyzes the extent and characteristics of Industry 4.0 technology implementation in two technologically and industrially leading countries—China and the United States. Using a comparative analytical approach, the study examines the relationship among annual vehicle production volumes, the intensity of industrial robot adoption, and the level of integration of smart manufacturing systems. Particular emphasis is placed on robotics, including industrial and collaborative robots, as central enablers of efficiency, flexibility, and innovation in modern production processes. The analysis also encompasses the core components of Industry 4.0, such as cyber-physical systems, the Internet of Things (IoT), digital factories, artificial intelligence (AI), and digital twins, which together enable the real-time integration of humans, machines, and data. Furthermore, current trends in robotization and digital integration of manufacturing facilities are discussed through a comparison of national industrial policies, development strategies, and investment priorities. The research results indicate that China maintains an advantage in terms of absolute production volume and the number of installed robots, while the United States leads in the development of highly automated, flexible, and intelligently networked manufacturing systems. It is concluded that different approaches to the implementation of Industry 4.0 technologies shape distinct models of technological competitiveness, innovation, and long-term sustainable development in the automotive industry.

Influence and Analysis of a Viscosity-Velocity Combined Prediction Model on the Dynamic Thermodynamic Performance of Shell-and-Tube Heat Exchangers in Offshore/Coastal Marine Energy Systems

To address the lack of dynamic prediction methods for heat exchangers operating under variable-viscosity and fluctuating-flow conditions in marine integrated energy systems, this study develops a dynamic wall-temperature prediction model for a shell-and-tube heat exchanger under combined viscosity-flow conditions. The model is established over flow velocities of 0.8–1.5 m/s and kinematic viscosities of 1.45 × 10⁻⁶–1.45 × 10⁻⁵ m²/s, representing fouling-prone operating conditions relevant to seawater/sewage-source heat pump applications. The main novelty of the study lies in linking viscosity-flow combined with wall-temperature dynamics in a unified prediction framework and in quantifying the nonlinear thermal response over a practically relevant operating range. The results show that a quartic polynomial relationship with flow velocity and viscosity can describe wall temperature. A distinct dynamic response pattern is observed: under low-viscosity conditions, wall temperature exhibits pronounced multi-peak fluctuations, whereas under high-viscosity conditions, it shifts to a more stable single-peak or gently declining trend. This behavior helps clarify the physical mechanism governing wall-temperature evolution under combined transport effects. In addition, the sewage-side heat transfer coefficient increases by up to 41.3%, while the overall heat transfer coefficient increases by 18.2–20.6% over the investigated range. These findings provide a dynamic prediction tool for heat exchanger performance in seawater-source heat pump systems integrated with intermittent marine renewable energy (such as offshore wind and wave power), and further indicate that the proposed model can offer useful mechanism-level insight into the dynamic thermal behavior of fouling-prone heat exchangers, thereby supporting the design and operation of seawater/sewage-source heat pump systems integrated with intermittent marine renewable energy sources such as offshore wind power.