6PPD (N1-(4-methylpentan-2-yl)-N4-phenylbenzene-1,4-diamine), a widely used rubber antioxidant in tire manufacturing, has garnered increasing global attention, following the discovery that its ozone-oxidation product, 6PPD-q, is the primary toxicant responsible for urban runoff mortality syndrome (URMS) in salmon. This work provides a comprehensive review of 6PPD and 6PPD-q in the environment, focusing on four key aspects: source, occurrence, transformation, and toxicity. 

Key findings include the following: (1) Tire wear particles are the main source of 6PPD and 6PPD-q in the environment, with their release directly linked to traffic density. (2) Ozone levels, temperature, climate conditions (e.g., snowmelt and rainy seasons), and environmental settings (e.g., roadways, tunnels, and parking lots) can greatly affect exposure levels. (3) In addition to atmospheric ozonation, oxidation in the atmosphere, free radical oxidation, and photocatalytic oxidation also play key roles in transforming 6PPD to 6PPD-q within aquatic systems and soils. (4) URMS is caused by 6PPD-q attacking the organs of fish, leading to blood–brain barrier and vascular dysfunction, with observed interspecies differences in sensitivity; these differences may be linked to variations in metabolic capacity. (5) Both 6PPD and 6PPD-q can enter the human body through the food chain, but their metabolic mechanisms and pathological changes are still unclear. 

Given the significant research gaps, this review concludes with proposed future research directions to deepen understanding of 6PPD’s and 6PPD-q’s environmental impacts.

This paper introduces a novel home-health-care framework based on fusion of the industry-standard Matter protocol and a fragment of computational epistemic logics we have long used in our AI work. The Matter protocol provides for interoperability of devices between different vendors; the epistemic-logic component allows for robust reasoning about the knowledge and beliefs of the system and the agents it interacts with. 

Devices (wearable health watches, cameras, etc.) in this framework obtain continuous monitoring data from a patient living at home with a chronic health condition (heart attack, asthma, or extreme allergies) and reason agentically about this information in an epistemically aware manner. Based on data and reasoning, the AI can determine if a potential emergency event is occurring and notify health authorities and emergency services of the situation. 

By merging Matter protocol with epistemic logic, we integrate the most promising health-specific tools on the market, make defeasible and explainable solutions for a potential emergency, and allow for standardization of chronic-disease patient care in the home environment.

Ceramic coatings may exhibit immense potential due to their excellent corrosion resistance in high-temperature environments, such as molten salts. However, their application is often constrained by fracture under thermomechanical loads, primarily caused by the thermal expansion mismatch between ceramics and metals. A promising approach to mitigate such fracture is the use of graded designs incorporating ceramic-metal (cermet) composites as transitional interfaces between the pure ceramic and metal layers. Designing an optimal graded structure, however, is complex due to the numerous parameters governing composition, thickness, and property gradients. 

This work presents an integrated methodology that combines high-throughput finite element (FE) simulations and experimentation to design, optimize, and validate fracture-resistant graded cermet coatings. A ZrN–SS316L functionally graded cermet design was developed and optimized under thermomechanical loading conditions. The optimal designs guided by FE analysis were validated through XRD residual stress measurements and experimental fabrication. The optimized coating remained intact and fracture-free and survived multiple cycles of thermal transient testing up to 1100 °C with rapid heating and cooling rates of 3.3 °C/s and 16 °C/s, respectively. These results demonstrate the effectiveness and reliability of the FEM-guided and experimentally validated framework for functional materials design and optimization.

Creating a comprehensive, thoughtfully designed, and impactful learning experience abroad can be an overwhelming and uncertain undertaking. This article focuses on how leadership educators can address challenges, anticipate barriers, and design a leadership learning abroad course that powerfully supports student learning and avoids excess stress in the process. This article explores leadership learning in short-term study abroad programs through the lens of adaptive leadership. 

Using reflective narrative and practice-based examples, I examine the opportunities (the good), barriers (the bad), and ethical tensions (the uncertain) that arise when designing and facilitating leadership learning abroad. The article highlights faculty preparation and learning as a critical and often overlooked outcome of education abroad and situates leadership learning as a shared, relational process among students, educators, institutions, and community partners. I offer recommendations for leadership educators, institutions, and the field to support ethically grounded, developmentally appropriate, and adaptive leadership learning in global contexts.

The RNA revolution, advancing beyond traditional vaccines to new therapeutic modalities and constructs such as self-amplifying RNA (saRNA) and circular RNA (circRNA), continues to place increasing pressure on downstream purification. Diffusion-limited resins, the time-tested workhorse of protein purification, are fundamentally incompatible because mRNA is an enormous (>40 nm) molecule with low diffusivity (10−11–10−12 m2/s). 

Our perspective, rooted in core chemical engineering principles, applies transport analysis and re-examines published performance data to demonstrate why even optimized perfusion chromatographic resin systems, exhibiting 0.1 % of total flow through the resin particles, cannot overcome the inherent diffusional barriers preventing efficient RNA purification. Alternatively, convection-based devices, notably membranes and monoliths, are well situated as their transport characteristics are not limited by the molecular transport properties of RNA. Ultimately, pressure-driven flow enables the potential for increased device capacity at orders of magnitude (103x) lower process time and smaller device footprint contributing to markedly improved productivity. 

Taken together, these findings suggest that a paradigm shift is required toward convective membrane systems to create a platform capable of delivering scalable, economic, and ultimately industrially attractive mRNA purification.