Temperature-Tunable Heliconical and Ferroelectric Nematics for White Lasing.

Nematic Liquid Crystals (LCs), noted for their simple molecular alignment and broad use in optoelectronics, remain unmodified for over a century. However, in 2017, a unique polar phase, the ferroelectric nematic (N), is confirmed. Subsequently, in 2024, the revolutionary spontaneous mirror symmetry breaking of ferroelectric twist-bend nematic chiral structures (N phase) is demonstrated.

Self-Assembly of Bent-Core Nematics in Nanopores.

Bent-core nematic liquid crystals exhibit unique properties, including giant flexoelectricity and polar electro-optic responses, making them ideal for energy conversion and electro-optic applications. When confined in nanopores, they can stabilize chiral nanostructures, enhance polar order, and enable defect-driven switching - offering potential in nanofluidics, sensing, and adaptive optics. The thermotropic ordering of the bent-core dimer CB7CB confined in anodic aluminum oxide (AAO) and silica membranes with precisely engineered cylindrical nanochannels - ranging from just a few nanometers to several hundred nanometers-is examined.

Recognizing the Universality of Copper Reconstruction Via Dissolution-Redeposition at the Onset of CO Reduction.

The electrochemical CO reduction (ECOR) on copper (Cu) remains one of the most promising pathways to convert CO into value-added products. However, it suffers from severe restructuring, resulting in the unknown structural identity of the ECOR active catalyst. Here, we show that dissolution-redeposition is the universal early-stage restructuring mechanism in ECOR, occurring across all the tested Cu morphologies, including foils, nanoparticles, oxide-derived films, and gas diffusion electrodes.

Performance of the ChatGPT-4o Language Model in Solving the Ophthalmology Specialization Exam.

Background Artificial intelligence (AI), particularly language models such as ChatGPT, is gaining importance in medical education and knowledge assessment. Previous studies have demonstrated the growing effectiveness of AI in solving medical exams, including the Final Medical Examination (LEK) and Polish State Specialization Exam (PES) in various specialties, raising questions about its usefulness as a tool to support specialist training processes. Objective The aim of this study was to assess the effectiveness of the latest ChatGPT-4o model in solving the PES in ophthalmology.

Machine Learning-Based Assessment of Parkinson's Disease Symptoms Using Wearable and Smartphone Sensors.

This study explores the use of machine learning models to assess the severity of Parkinson's disease symptoms based on data from wearable and smartphone sensors. It presents models to predict the severities of individual symptoms-tremor, bradykinesia, stiffness, and dyskinesia-as well as the overall state of patients, using both clinician and patient self-assessments as labels. The dataset, although limited and imbalanced, enabled the identification of key trends.

A Refractive Index Sensor Based on Spectral Interrogation of a Long Tapered Side-Hole Optical Fiber.

This article describes an external refractive index (RI) sensor based on a spectral analysis of the light transmission through a long tapered side-hole optical fiber (S-H OF). A section of the S-H OF was fusion-spliced with SMFs at both ends and connected to a supercontinuum source at the input and an optical spectrum analyzer (OSA) at the output. To investigate the effect of the external RI on the spectral characteristics, immersion liquids with refractive indices in the ranges of 1.

Physico-Mechanical Properties of 3D-Printed Filament Materials for Mouthguard Manufacturing.

Mouthguards are recommended for all sports that may cause injuries to the head and oral cavity. Custom mouthguards, made conventionally in the thermoforming process from ethylene vinyl acetate (EVA), face challenges with thinning at the incisor area during the process. In contrast, additive manufacturing (AM) processes enable the precise reproduction of the dimensions specified in a computer-aided design (CAD) model.

Comparative Study on Mechanical Performance and Toughness of High-Performance Self-Compacting Concrete with Polypropylene and Basalt Fibres.

This study investigates the flexural performance, tensile splitting strength, and fracture behaviour of self-compacting concrete (SCC) reinforced with polypropylene (PP) and basalt (BF) fibres. A total of eleven SCC mixtures with varying fibre types and volume fractions (0.025-0.

The Influence of Rolling Direction and Dynamic Strengthening on the Properties of Steel.

The article presents an analysis of the mechanical properties of S700MC steel, which represents advanced low-alloy high-strength steels. The influence of microstructure, shaped by a controlled thermo-mechanical rolling process, on the strength, ductility, and resistance to cracking and fatigue of the material is discussed. Particular attention is paid to the anisotropy of mechanical properties resulting from the orientation relative to the rolling direction, manifested by variations in yield strength, tensile strength, and total elongation of the specimens.

Analysis of the Possibility of Increasing the Load-Bearing Capacity and Fatigue Life of CFRP Material Mechanical Joints.

Achieving a high load-bearing capacity and fatigue life of joints of composite structures is possible with the use of mechanical fasteners. The aim of this research was to search for effective methods of increasing the load-bearing capacity of mechanical joints of CFRP components. A CFRP composite was made from carbon fabric (KORDCARBON, Czech Republic) using vacuum bag technology.

Resonant Cavity Effect for Spectrally Tunable and Efficient Narrowband Perovskite Photodetectors.

Narrowband photodetectors with precise spectral control offer significant potential for applications such as color imaging and machine vision. However, existing demonstrations have encountered challenges due to restricted absorption, the need for additional filters, or the inclusion of thick absorbing layers to facilitate charge collection filtering mechanisms. These constraints have resulted in suboptimal detectivity, inadequate color control, or slow response.

Spatial confined hot carrier dynamics for beyond unity quantum efficiency detection.

Photon harvesting and conversion in semiconductors hold critical scientific and technological value due to their wide-ranging applications, including optoelectronics, renewable energy, and thermal management. However, the efficiency of optical-to-electrical energy conversion is fundamentally limited by the rapid relaxation of thermalized carriers. Here, we demonstrate a spatial confinement-controlled hot carrier dynamics in a T-shape lead selenide photo-thermoelectric device, which achieves a room temperature external quantum efficiency values exceeding unity.

Effect of shear flow on the electric polarization of a Sm-C^{*} liquid crystal.

The electric polarization of ferroelectric Smectic-C^{*}(SmC^{*}) liquid crystal is always measured on static samples confined between two fixed electrodes. Here, we study the effect of shear flow on the electric polarization of a SmC^{*} liquid crystal. We observe three distinct regimes in the shear rate-dependent polarization curve.

Mechanochemical Preparation of Biomass-Derived Porous Carbons.

Conventional methods for the synthesis of porous carbons are typically time- and energy-consuming and often contribute to the excessive accumulation of waste solvents. An alternative approach is to employ environmentally friendly procedures, such as mechanochemical synthesis, which holds great potential for large-scale production of advanced carbon-based materials in coming years. This review covers mechanochemical syntheses of highly porous carbons, with a particular focus on new adsorbents and catalysts that can be obtained from biomass.

Laser Surface Hardening of Carburized Steels: A Review of Process Parameters and Application in Gear Manufacturing.

This article provides a comprehensive overview of recent studies concerning laser heat treatment (LHT) of structural and tool steels, with particular attention to the 21NiCrMo2 steel used for carburized gear wheels. Analysis includes the influence of critical laser processing conditions-including power output, motion speed, spot size, and focusing distance-on surface microhardness, hardening depth, and microstructure development. The findings indicate that the energy density is the dominant factor that affects the outcomes of LHT.

Rapid synthesis of graphitic carbon nitride nanosheets as an efficient adsorbent for removal of Methylene Blue and Rhodamine B from Aqueous Solutions.

Toxic dyes present in wastewater pose a severe threat to aquatic ecosystems, emphasizing the urgent need for eco-friendly and efficient remediation strategies. In this study, we report a novel rapid synthesis protocol for graphitic carbon nitride (g-CN) nanosheets via thermal polymerization of thiourea, followed by annealing in ambient air at 550 °C for two hours. The resulting g-CN nanosheets were employed as adsorbents for the removal of methylene blue (MB) and rhodamine B (RhB) from aqueous solution.

Endovascular structures of the basilar artery as forms of the basilar nonfusion spectrum.

Cerebrovascular diseases are a growing social and clinical problem. The intravascular anatomy of the cerebral circulation remains poorly understood, although an increasing number of endovascular interventions are being conducted. The purpose of this study was to describe intravascular structures in the vertebrobasilar system and to investigate the hemodynamic consequences of their presence.

Triple-doped Dy/Tb/Eu activated NaCa(PO)F halo-phosphors for next-generation WLEDs and solar cell efficiency enhancement.

This study reports the synthesis and characterization of NaCa(PO)F phosphor doped with Dy, Tb, and Eu ions were synthesized using a conventional solid-state method. The phase formation was confirmed by X-ray diffraction (XRD). Functional group analysis through Fourier transforms infrared spectroscopy (FTIR) and morphological evaluation via scanning electron microscope (SEM) and EDS revealed good crystallinity and elemental distribution.

Degradation of the Surface of Synthetic Layered Composites Due to Accelerated Ageing.

This study investigates the effect of accelerated aging on the microstructure and surface properties of synthetic sports surfaces, with the goal of developing a more representative laboratory simulation method. Three common types of polyurethane-based sports surfaces were examined: (1) a dual-layer SBR base with a thin EPDM spray topcoat; (2) a single-layer EPDM surface with a smooth finish; and (3) a dual-layer "sandwich" structure with a rough EPDM upper layer. Samples were tested for slip resistance (PTV), abrasion resistance, and surface morphology using SEM, as well as surface roughness and tensile properties before and after aging.

Monolayers of Amino Acid-Synthesized Gold Nanoparticles as SERS Substrates for Trace Chemical Sensing.

In recent years, extensive studies have been devoted to the applications of surface-enhanced Raman spectroscopy (SERS) in detecting and identifying trace amounts of various analytes. The crucial issue for SERS applications is the selection of reliable and reproducible substrates. Therefore, most studies were dedicated to their fabrication, characterization, and evaluation using selected test compounds.

Partially Disordered Crystal Phases and Glassy Smectic Phases in Liquid Crystal Mixtures.

Three liquid crystalline mixtures were investigated, consisting of compounds abbreviated as MHPOBC and 3F5FPhF6 with molar ratios 0.9:0.1 (MIX5FF6-1), 0.

Calorimetric Studies of the Mg-Pt System.

This study presents the limiting partial enthalpy of a solution of Pt in liquid Sn and Al baths, as well as, for the first time, the standard enthalpies of the formation of intermetallic phases and alloys of the Mg-Pt system, obtained using solution calorimetry. The alloys were prepared via mechanical alloying and subsequently examined via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The limiting partial enthalpy of a solution of Pt in liquid baths was measured at 931 K and 1033 K in the Sn bath and at 1036 K in the Al bath.

Microstructure Evolution of NiAl-Based Intermetallic Alloy Strips After Hot Rolling.

The effect of the temperature and strain rate during the hot rolling process on the microstructural evolution in fine-grained NiAl intermetallic alloy doped with Zr and B was examined in this work. The hot rolling process was carried out at an initial temperature range of 1000, 1100, and 1280 °C and at a strain rate between 3.9 × 10 s and 2.

Procedures for Building a Secure Environment in IoT Networks Using the LoRa Interface.

IoT devices typically have limited memory resources and computing power. For this reason, it is often not possible to use the authentication and trusted environment mechanisms commonly used on the Internet. Due to the autonomous operation of IoT devices, solutions that require user interaction should be excluded.

High efficiency of laser energy conversion with cavity pressure acceleration.

Cavity Pressure Acceleration (CPA) is a technique for accelerating dense plasma streams by utilizing laser-generated plasma pressure within a spatially confined region. This approach has been proposed as an alternative to the classical ablative acceleration of plasma. Initially, the primary goal of this approach was to create a dense plasma stream (a theoretical macroparticle delivering energy/momentum) suitable for experiments related to Impact Fast Ignition.