Introduction

Magnesium alloys are under intensive investigation because of their possible use in the biomedical field thanks to their good biocompatibility and mechanical properties which are similar to human bones and biodegradation. For instance, they have been used to produce a biodegradable bone fixator that does not require a second surgery. The main issue is the high corrosion rate in respect to tissue remodelling. The principal strategies to overcome this problem are: tailoring the alloy composition, inducing microstructural changes, employing surface treatments and coatings.

Several authors observed that the Layered Double Hydroxides (LDH) coatings improve the biocorrosion behaviour of the Mg-alloys and also permit drug delivery.

The aim of present work is to investigate how the microstructural changes induced by Equal Channel Angular Pressing (ECAP) affect the LDH films growth on the AZ31 surface.

Methods

The commercial AZ31 alloy was processed by 0, 1, 2 and 4 ECAP passes.

LDH structures were grown on AZ31 samples using the co-precipitation technique. The nutrient solution was: Zn(NO₃)₂*6H₂O (5 mM) and urea (15 mM) in 150 mL of distilled water. After preliminary cleaning the samples were immersed in the nutrient solutions, and kept there for 12 h at 90 C. Finally, they were cooled in the nutrient solution, extracted from the reactor, rinsed in distilled water and ethanol and air-dried.

The microstructural characterisation of the samples was performed by LM, XRD, SEM, EBSD technique.

Results

The LDH film was successfully grown on the surface of all the samples. The LDH crystals mostly present a dendritical shape. It was observed that the LDH film was more uniform after 1 ECAP pass with an average crystal size of 200 nm.

Conclusions

The microstructural evolution induced by ECAP favours a more homogeneous LDH growth due to the best trade-off between texture and presence of nucleation sites (twins, dislocations, GB etc.).

Wood is the most vital renewable building material, which has been widely used in outdoor and indoor areas because of its abundance and versatility. Due to its organic nature, wood is susceptible to attack by various biotic and abiotic factors. Therefore, in order to protect the wood against these factors, wood coating and preservative treatment become obligatory. The application of coatings is a common solution against wood-degrading factors. The wood coating performance depends on several factors, such as humidity, moisture content, the species of wood, and temperature. Furthermore, to improve wood coating performances, different strategies such as the addition of UV absorbers and radical scavengers are widely used. The wood treatment encompasses the impregnation of wood preservatives such as creosote, pentachlorophenol, CCA (chromated copper arsenate), alkaline copper quaternary (ACQ), and copper azole (CA), as they can inhibit degradation and increase durability against fungi and insects. In the present study, we investigated the combined effect of preservatives and coatings on surface characteristics of Melia dubia. The wooden specimens were impregnated with 4% ZiBOC and 4% BBA concentrations and were finished with wax polish, spirit shellac, and polyurethane. Furthermore, the gloss and thickness values were determined. The findings showed that among all three finishes, polyurethane shows preeminent results, followed by spirit polish and wax polish. In addition, the behaviour of ZiBOC preservative along with the finishes produces extraordinary results.

Virtual reality (VR) has the potential to offer an excellent opportunity for truly immersive experiences.
However, it can sometimes be challenging to discern changes in emotional state during immersive scenarios. It might be helpful to consider the use of a stress device to detect changes during the VR experience. This study investigates the potential effectiveness of an entirely in-house developed VR roller coaster simulation, consisting of a moving chair and a visor, providing a 3D scenario with adjustable speed and level of realism. During the ride, the participants kindly agreed to use a wearable stress detection device developed in-house, which is designed to collect biometric data using heartbeat and galvanic skin (i.e. sweat level) sensors. A comparative analysis of different clustering techniques (K-means, Agglomerative, Mean Shift and Gaussian Mixture Model) has been conducted using the biometric data with the aim of identifying the various levels of stress experienced by participants during the ride. At the conclusion of the VR experience, the participants were respectfully invited to complete a brief questionnaire to share their perceptions. These data were then cross-referenced with the stress levels obtained by the clustering to check for potential correspondences, crucial to assess the effectiveness of the VR experience. This will provide insight into whether VR experiences can have an impact on emotional states and consider the potential for VR to provide a comparable experience to reality.

Hormones are crucial in regulating physical and mental health and athletic sports performance. In particular, cortisol, estradiol, and testosterone monitoring can provide insights into their effects on mood, stress responses, and athletic performance.
Increasing levels of these hormones are linked to increased anxiety and depression, and measurements of their fluctuations can provide predictions of sports performance. Both sex hormones and cortisol significantly modulate stress responses, with distinct effects observed in men and women and in individuals undergoing hormone treatments. These insights underscore the importance of hormone monitoring for optimising mental health and athletic outcomes.
This work proposes a compact and low-cost multi-channel surface plasmon resonance (SPR) platform based on plastic optical fibers (POFs) combined with several specific bio-receptor layers as a point-of-care measurement tool. This multi-channel SPR-based tool is based on optical fiber components for precise, label-free, and high-throughput detection without complex and expensive instrumentation. The multi-channel SPR-POF tool is applied to simultaneous multi-analyte detection of cortisol, estradiol, and testosterone in saliva. The plasmonic POFs’ sensitive surfaces are functionalised with different bio-receptors, such as the Glucocorticoid Receptor (GR) and the Estrogen Receptor (ER). This compact and cost-effective multi-channel SPR-based point-of-care tool could be of interest for the simultaneous detection of several biomarkers in saliva for health and sports purposes.

Modern applications of molecular liquid crystals span from high-resolution displays for augmented and virtual reality to miniature tunable lasers, reconfigurable microwave devices for space exploration and communication, and tunable electro-optical elements, including spatial light modulators, waveguides, lenses, light shutters, filters, and waveplates, to name a few. The tunability of these devices is achieved through electric-field-induced reorientation of liquid crystals. Because the reorientation of the liquid crystals can be altered by ions normally present in mesogenic materials in minute quantities, resulting in their electrical resistivity having finite values, the development of new ways to control the concentration of the ions in liquid crystals is very important. A promising way to enhance the electrical resistivity of molecular liquid crystals is the addition of nano-dopants to low-resistivity liquid crystals. When nanoparticles capture certain ions, they immobilize them and increase their resistivity. If properly implemented, this method can convert low-resistivity liquid crystals into high-resistivity crystals. However, uncontrolled ionic contamination of the nanoparticles can significantly alter this process. In this paper, building on our previous work (Eng. Proc. 2023, 56(1), 199), we explore how physical parameters such as the size of the nanoparticles, their concentration, and their level of ionic contamination can affect the process of both enhancing and lowering the resistivity of the molecular liquid crystals. Additionally, we analyze the use of two types of nano-dopants to achieve better control over the electrical resistivity of molecular liquid crystals.

Inflammatory skin diseases, such as atopic dermatitis and psoriasis, can significantly impact patients' quality of life due to symptoms caused by an overactive immune response. Clobetasol, a potent corticosteroid, is commonly used to relieve these symptoms by reducing inflammation and suppressing immune responses. However, prolonged use can lead to adverse effects, including skin atrophy, hypopigmentation, and Cushing-like syndrome. To tackle these issues, nanotechnology has been extensively used to enhance drug strength, stability, and controlled release, improving therapeutic efficacy and safety. In this study, clobetasol-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles were developed and incorporated into a thermosensitive hydrogel for topical treatment of inflammatory skin diseases. Nanoparticles were prepared by nanoprecipitation using PLGA (polymer), polyvinyl alcohol (PVA, stabilizer), acetone (solvent), and clobetasol (drug). Particle size, polydispersity index (PDI), and zeta potential (ZP) were determined using a Zetasizer Nano ZS. Optimized nanoparticles for topical drug absorption exhibited an average size of 232 ± 20 nm, PDI of 0.18 ± 0.06, and a slightly negative surface charge (-6.94 ± 2.55 mV), consistent with PLGA’s ester terminals. Thermosensitive hydrogels were successfully formulated using the cold method for nanoparticle incorporation, displaying a gelation temperature (32.33 ± 0.58°C) identical to skin temperature. In vitro studies revealed controlled release of clobetasol from the nanoparticles and the hydrogel incorporated with the nanoparticles, with the latter showing a lower cumulative percentage. Therefore, both formulations offer a promising therapeutic approach for treating inflammatory skin diseases, minimizing clobetasol-related side effects through controlled release.

1. Introduction

Gold nanoparticles have gained a lot of interest in medical applications due to their plasmonic properties, and many methods have been explored for synthesizing well-defined particles. The detection of blood glucose using gold nanoparticles is emerging as a new method. In this project, we developed gold nanoparticles, using glucose as a mild reducing and stabilizing agent, to detect glucose in the blood through plasmonic reactions. By exploring innovative technologies and emerging techniques, we aim to enhance the accuracy, convenience, and overall user experience of glucose monitoring when using our potential method. The preliminary results will be presented.

2. Methodology

Various glucose concentrations were meticulously prepared and combined with a consistently proportioned gold solution to synthesize the gold nanoparticles. Sodium hydroxide and heat were employed to accelerate the process. The synthesized nanoparticles were characterized using absorption spectroscopy and electron microscopy.

3. Results and Application

Glucose is a mild reducing agent, and it reduces the gold salt into gold nanoparticles. The formation of gold nanoparticles was confirmed by measuring the surface plasmon resonance peak around 500 nm. The detection limit was in the range of 2mM to 50 mM with good reducibility, showing the potential application of this method. We are currently working on the interference of other ions/enzymes present in the blood with this procedure and expect to develop a potential method for glucose detection in blood and saliva.

Introduction

An optimal wound dressing should facilitate gaseous exchange, absorb excess exudate, establish a moist wound-healing environment, and be easily removed without causing damage to the wound. It should also be nontoxic, biocompatible, and antimicrobial. The leading causes of these performances are the material's functional properties and the microenvironment that was established. It seems that no single substance can fulfill all the demands for every phase of the healing process of wounds. In this project we have developed hydrogels based on gelatin and chitosan containing honey for wound healing applications, as honey is known to have antibacterial properties. Preliminarily we have studied the effect of various types of honey containing hydrogels as antibacterial materials. The preliminary results are presented in this study.

Method

Hydrogel films based on gelatin and chitosan containing various types of honey were prepared by solvent casting method. The antibacterial properties of the material were tested using the incubation method. The surface morphology was studied by electron microscopy and swelling in water was measured gravimetrically.

Results

The hydrogel in water exhibited excellent swelling with high equilibrium water content and excellent mechanical properties. In the presence of bacteria, the hydrogels degraded slowly due to disintegration of collagen matrix by the bacteria. Interestingly, the hydrogels containing Manuka honey exhibited good antibacterial properties.

Conclusion and work-in-progress

Based on the formulation containing manuka honey, cell-growth on the hydrogel is currently in progress.

Drying is one of the most important processes for improving wood properties. Several methods are followed to dry wood; however, kiln drying is mainly used at industrial scales. The conventional method of kiln drying is very time-consuming and labour- and energy-intensive. Microwave heating has emerged as an effective technology for accelerating the drying process while minimising defects. This study focuses on the microwave drying characteristics of Gmelina arborea wood, a highly sought-after material in various industries. Drying experiments were conducted in a microwave oven operating at a frequency of 2.45 GHz, using two different power levels (540 W and 900 W). The samples were dried from an initial moisture content of about 130% to 12%. The drying cycles involved continuous exposure to microwave for 1 minute, followed by a 3-minute cooling period, repeated until the desired moisture content was achieved. The temperature profile of wood samples during the drying experiments was measured using an infrared camera. The results indicate that the drying rate was significantly higher in the MW drying experiments carried out at 900 W compared to those at 540 W. Additionally, the drying rate above the fibre saturation point (FSP) was higher than that below the FSP for both power levels. Notably, the total drying time for samples irradiated at 900 W (99 minutes) was nearly half, compared to samples dried at 540 W (213 minutes). However, out of the total drying time, the effective microwave time incurred in drying wood samples at 900 W and 540 W was 25 and 53 minutes, respectively. The moisture distribution between the core and surface was very uniform, and the quality of the dried wood was good, with only slight internal checks. This study demonstrates that microwave heating can be effectively utilized for the rapid and high-quality drying of Gmelina arborea wood.

Using natural plant extracts in cosmetics has grown since the early twenty-first century. Waste biomass from berry crops is being studied for its potential to create high-value products, with encapsulation playing a key role in preserving plant extracts and enhancing their bioavailability. Among them, ethosomes, specialized ultra-deformable liposomes produced with a higher ethanol content, have demonstrated effectiveness in delivering medicinal compounds through the skin without causing adverse effects. They have been used in various cosmetic products for skin treatments and hair care, such as those with coenzyme Q10 or vitamins A and E, which help protect the skin from oxidative stress, improve skin hydration, and reduce signs of aging. They are also employed in skin-whitening agents (e.g., for kojic acid, hydroquinone encapsulation) and anti-hyperpigmentation treatments. This study introduces a novel approach to enhancing the commercial potential of berry crop by-products. Commercial raspberry leaf extracts were encapsulated in an ethosomal system through the cold method and thoroughly characterized using laser dispersion, zeta potential, encapsulation efficiency, colorimetry, and optical microscopy, revealing a mean particle size (D4:3) of 2.48 to 10.80 µm and entrapment efficiency (EE%) of 51.79% to 72.25%. The zeta potential ranged from -40.06 mV to -30.93 mV. Results suggest that ethosomes are an effective method for encapsulating hydroethanolic bioactive plant by-product extracts. These findings are significant as they make these encapsulated extracts suitable for various industrial applications. Particularly in the cosmetics industry, where the demand for natural and effective ingredients is rapidly increasing, present research could have a significant impact.