Visualization of Latent Fingermark on Metallic Surfaces Based on Displacement Reactions

Fingermarks are frequently left on metal surfaces such as kitchen utensils, door handles, or elevator buttons in crime scenes. They are crucial forensic evidence to identify individuals and link them to crimes. Fingermark development on metal surfaces targets either the fingermark residues or the substrate. This study aimed to develop a rapid fingermark development method based on displacement reactions between copper (II) sulphate and various types of metal substrates, such as brass, galvanized iron, and low-carbon steel. Immersion of the metal substrate was more effective in fingermark visualization than applying the solution using a dropper. The optimized concentrations of copper (II) sulphate solution for fingermark visualization were found to be 0.7 M for brass, 0.5 M for galvanized iron, and 0.2 M for low-carbon steel. Sebaceous-rich fingermarks were visualized after the 5th depletion on brass and galvanized iron, and even after the 7th depletion on low-carbon steel. Further improvement is required before incorporating the application of copper (II) sulphate onto metal substrates to visualize fingermarks in real crime cases, due to the destructive nature of substrate submersion.

When Numbers Mislead: Reassessing Statistical Foundations in PCA-Based Prognostication of Fontan Outcomes

Contemporary Multimodality Imaging Evaluation in Native Aortic Stenosis

Aortic stenosis (AS) is the most prevalent valvular heart disease in developed nations, with increasing incidence driven by population aging. Early and accurate diagnosis is crucial, as timely intervention significantly improves outcomes. Contemporary imaging plays a central role in the assessment of AS, enabling precise evaluation of valve anatomy, disease severity, left ventricular remodeling, and procedural planning. Transthoracic echocardiography remains the first-line modality, providing essential hemodynamic and structural data. However, limitations in cases of low-flow states, discordant grading, and atypical presentations necessitate adjunctive tools. Transesophageal echocardiography enhances visualization of valve morphology and annular dimensions, particularly for pre-procedural assessment. Cardiac computed tomography (CT) has emerged as a cornerstone in transcatheter aortic valve replacement (TAVR) planning, offering unparalleled spatial resolution for annular sizing, coronary height measurement, and vascular access evaluation. Meanwhile, cardiac magnetic resonance (CMR) provides robust quantification of ventricular volumes, fibrosis, and myocardial strain, serving as a prognostic marker in asymptomatic and borderline cases. The integration of multimodality imaging offers a comprehensive framework, addressing diagnostic ambiguities and guiding individualized management strategies. This review highlights current advances, clinical applications, and future directions in multimodality imaging for AS, emphasizing its pivotal role in optimizing patient selection, risk stratification, and procedural outcomes.

Construction and Applications of Efficient, Oxygen-Tolerant Triplet-Triplet Annihilation Upconversion Materials

Triplet–triplet annihilation upconversion (TTA-UC) is an emerging class of photonic upconversion materials notable for low excitation power thresholds, high upconversion quantum yields, and tunable absorption and emission profiles. These unique features give TTA-UC materials significant potential across diverse fields such as chemistry, biology, and materials science. A typical TTA-UC system consists of sensitizers and annihilators, functioning through a sequence where the sensitizer absorbs photons and transfers triplet energy to the annihilator via triplet–triplet energy transfer, followed by triplet–triplet annihilation (TTA) that emits higher-energy photons. Because TTA-UC materials can be excited by long-wavelength light, they overcome the limitations in penetration depth of conventional fluorescence technologies, showing great promise for applications such as deep-tissue imaging, targeted photodynamic therapy, and precise optogenetic modulation. However, molecular oxygen causes non-radiative decay pathways that severely quench upconversion efficiency, posing a major challenge for practical use. Over the past decade, researchers have developed various innovative strategies to counteract oxygen-induced quenching. This review systematically summarizes key scientific approaches to creating high-performance, oxygen-tolerant TTA-UC materials, with a focus on their underlying mechanisms. First, we discuss molecular engineering strategies involving electron-deficient groups and conformational control to improve the photostability of TTA-UC chromophores. Second, we describe the fabrication of oxygen-resistant TTA-UC nanoparticles using reductive oil droplets as soft templates. Finally, we discuss nanostructure-mediated optimization of intermolecular triplet energy transfer dynamics to enhance oxygen resilience. A critical evaluation of the advantages and limitations of each approach is provided. Additionally, we highlight key challenges, including improving the upconversion efficiency of near-infrared-responsive TTA-UC, developing novel nanoparticle fabrication methods, and refining surface bioconjugation chemistry. We conclude by exploring prospects for integrating TTA-UC with synthetic biology techniques to design biosynthetic upconversion proteins, potentially establishing upconversion luminescence as a vital tool in fundamental life science research and accelerating its application in diverse biomedical fields.

3D-Printed Continuous Fiber Composites: An Overview of Materials, Systems and Processes

3D-printed composites represent a cutting-edge advancement in additive manufacturing, offering the ability to fabricate high-strength, lightweight structures by embedding continuous fibers within a single deposition process. This innovative approach significantly enhances the mechanical performance of printed parts compared to traditional polymer-based 3D printing. In this article, we present a structured review of recent developments in 3D-printed composite technologies. The discussion is organized into three key areas: (i) the types and properties of continuous fibers used in 3D printing, (ii) the underlying mechanisms and systems that enable fiber deposition, and (iii) emerging strategies involving commingled materials that integrate reinforcement and matrix components at the filament level. This review aims to provide a comprehensive understanding of the current state and future directions of continuous fiber-reinforced additive manufacturing.

The Jevons Paradox and Vernon’s Product Life Cycle: Evidence from Primary–Secondary Price Differentials in Copper and Aluminium (2002–2021) with 2024–2025 Market Context

This study examines how efficiency improvements associated with Jevons’ Paradox and product-system maturation, as described by Vernon’s Product Life Cycle (PLC), jointly influence the long-term pricing relationship between primary and recycled copper and aluminium. Using author-provided nominal annual USD price series for 2002–2021, the analysis derives descriptive indicators most notably the recycled-to-primary (R/P) price ratio to characterize structural shifts consistent with PLC-driven secondary integration. Recent market conditions in 2024–2025, including tight physical availability, low inventories, regional premia, and recurrent episodes of backwardation, are incorporated as qualitative context without merging with the historical dataset. Results indicate a sustained narrowing of R/P discounts for both metals by 2021. The combined Jevons–PLC interpretation suggests that efficiency-driven service expansion and supply-side tightness increase the relative value of secondary material, supporting long-term convergence between primary and recycled streams.

Toluene or Formaldehyde Removal by Photocatalysis and Adsorption Using Hybrid Optical Fiber Textiles Containing Activated Carbon and/or TiO₂

Indoor air treatment has become a significant concern in recent years. The aim of this study is to investigate the effectiveness of coupling adsorption and photocatalysis for the removal of toluene and formaldehyde, especially in the presence of optical fiber textile. First, we examine the adsorption properties of various commercial activated carbon (AC) filters, as well as different amounts of AC deposited on optical fiber textiles, and assess the impact of titanium dioxide (TiO₂) on the adsorption performance. In the second phase, we compare the photocatalytic degradation of toluene and formaldehyde under different irradiance levels. Finally, we analyze the impact of three AC-TiO₂ combinations: separate filters, TiO₂ deposited on AC-impregnated fiber optic textiles, and TiO₂ partially deposited on AC filters. The results led us to test a new photocatalytic and adsorbent material, including heating wires and optical fibers.

Design and Implementation of an Autonomous Smart Food Delivery Robot for Commercial Environments

The integration of robotics into service environments is transforming how labor-intensive tasks are managed, particularly during peak hours with staff shortages and long wait times. This research presents a fully autonomous, modular food-delivery robot designed to enhance operational efficiency and improve service experience. The system combines artificial intelligence, facial recognition, smartphone-based order management, Arduino, ESP32, ESP32-CAM, and Python to navigate indoor environments and deliver food directly to recipients, supported by a secure handover mechanism. Experimental results indicate that the robot performs waiter-like delivery reliably, maintaining mobility and structural integrity across various surfaces by using lightweight materials and motors that have been optimized. Through the use of a motion coordination algorithm, responsive navigation can be achieved, while a simple user interface can be operated by anyone with minimal training. According to these results, automation reduces the need for manual labor, increases the speed of service, and ensures consistency in the delivery process. Additionally, the system provides a practical framework for future research and potential applications beyond food delivery, such as surveillance, environmental monitoring, and disaster response. Future work will focus on scaling for real-world deployment and integration advanced AI navigation to enhance autonomy, adaptability, and overall operational performance.

Insights in Applying Self-Determination Theory to Study Chinese Students’ Positive Functioning: Review of Current Literature and Suggestions for Future Directions

Self-determination theory (SDT) is a prominent theory in psychology and has been applied extensively to student populations to explain their positive functioning. However, its validity in Chinese contexts has been questioned. The current paper provides an up-to-date review of the validity of SDT propositions when applied to Chinese education, and points out promising future directions of inquiry. Specifically, reviewing literature identified using Google Scholar and published by key research labs, we show that by examining well-established SDT models in Chinese population, research from the last about two decades shows a “universalism without uniformity” pattern, supporting the validity of the general SDT model regarding the basic relationships between social contexts, basic psychological needs, motivation, and positive outcomes, while allowing for variability in effect strengths. However, there is a dearth of attention paid to a few important issues that have emerged within cultural and positive psychology recently. These issues suggest that future studies should focus on (1) testing the role of self-determination in forms of individual well-being that are more grounded in and representative of the Chinese culture, (2) testing the role of self-determination on collective-level indicators of well-being, and (3) testing other contextual issues in Chinese culture beyond the collectivist aspect.

Synthesis, Spectroscopic Characterization Techniques, and Functional Applications of Selenium Heterocycles

The paper reviews the unique chemical properties of selenium, focusing on selenium-containing heterocycles and organoselenium chemistry. The present study undertakes a critical examination of synthetic strategies, ranging from classical nucleophilic selenation and transition-metal catalysis to emerging photo-redox and electrochemical approaches. The text goes on to highlight advanced characterisation techniques, with particular reference to the combination of ⁷⁷Se NMR spectroscopy with DFT calculations and single-crystal X-ray diffraction for structural elucidation. The functional applications of these compounds are the subject of extensive discussion, including their role in enhancing the performance of sustainable organic photovoltaic (OPV) materials for renewable energy conversion, and their potential in biomedicine as TrxR inhibitors for cancer therapy and as photosensitizers in antibacterial applications. The present study places particular emphasis on the contribution of selenium-containing heterocycles to improving the power conversion efficiency (PCE) of solar devices. Finally, the review outlines future research directions and common challenges in this field, such as enhancing the sustainability of catalytic processes and addressing biosafety concerns associated with selenium-based reagents.