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This study investigated the dose-dependent changes in the chemical composition of three dental ceramic materials—zirconia, lithium disilicate (LD), and VITA ENAMIC® hybrid composite (VITA En)—following irradiation with an ultra-short femtosecond (fs) laser (800 nm, 30 fs, 1 kHz) in an ambient air environment using average laser power (76 mW) and scanning speeds (50, 100, and 200 mm/s), simulating dental treatment processes. The chemical composition of the ablated regions was analyzed using energy dispersive spectroscopy. All irradiated samples showed increased carbon content (by up to 42%) and reduced oxygen (by up to 33%). The observed increase in C content is likely attributed to a combination of surface reactions, adsorption of carbon from the ambient environment, and carbon deposition from the laser-induced plasma, all facilitated by the high-energy conditions created by fs-laser pulses. Scanning electron microscopy revealed ablation with progressive controlled melting and recrystallization, with an absence of pile-up features typically associated with significant thermal damage. These findings demonstrate that ultra-short fs-laser irradiation induces highly controlled, dose-dependent changes in the chemical composition and surface morphology of dental ceramic materials.

The nerves of the peripheral nervous system are not able to effectively regenerate in cases of severe neural injury. This can result in debilitating consequences, including morbidity and lifelong impairments affecting the quality of the patient’s life. Recent findings in neural tissue engineering have opened promising avenues to apply fibrous tissue-engineered scaffolds to promote tissue regeneration and functional recovery. These scaffolds, known as neural scaffolds, are able to improve neural regeneration by playing two major roles, namely, by being a carrier for transplanted peripheral nervous system cells or biological cues and by providing structural support to direct growing nerve fibers towards the target area. However, successful implementation of scaffold-based therapeutic approaches calls for an appropriate design of the neural scaffold structure that is capable of up- and down-regulation of neuron-scaffold interactions in the extracellular matrix environment. This review discusses the main challenges that need to be addressed to develop and apply fibrous tissue-engineered scaffolds in clinical practice. It describes some promising solutions that, so far, have shown to promote neural cell adhesion and growth and a potential to repair peripheral nervous system injuries.

Abstract The use of carbon nanotubes as anticancer drug delivery cargo systems is a promising modality as they are able to perforate cellular membranes and transport the carried therapeutic molecules into the cellular components. Our work describes the encapsulation process of a common anticancer drug, Isatin (1H-indole-2,3-dione) as a guest molecule, in a capped single-walled carbon nanotube (SWCNT) host with chirality of (10,10). The encapsulation process was modelled, considering an aqueous solution, by a molecular dynamics (MD) simulation under a canonical NVT ensemble. The interactions between the atoms of Isatin were obtained from the DREIDING force filed. The storage capacity of the capped SWCNT host was evaluated to quantify its capacity to host multiple Isatin molecules. Our results show that the Isatin can be readily trapped inside the volume cavity of the capped SWCNT and it remained stable, as featured by a reduction in the van der Waals forces between Isatin guest and the SWCNT host (at approximately − 30 kcal mol−1) at the end of the MD simulation (15 ns). Moreover, the free energy of encapsulation was found to be − 34 kcal mol−1 suggesting that the Isatin insertion procedure into the SWCNT occurred spontaneously. As calculated, a capped SWCNT (10,10) with a length of 30 Å, was able to host eleven (11) molecules of Isatin, that all remained steadily encapsulated inside the SWCNT volume cavity, showing a potential for the use of carbon nanotubes as drug delivery cargo systems.

The necessary application of sustainable engineering methodologies has been increasing as the number of environmental hazards caused by global warming is on the rise. Cement as a traditional common additive for soil improvement has several negative impacts on the environment. This led to an urge for alternative sustainable solutions. The use of biopolymers as environmentally friendly materials is one of the potential options. This study aims to investigate the effect of xanthan gum biopolymer as a sustainable solution for soil properties enhancement. The Atterberg limits, unconfined compression, CU and UU triaxial tests were performed to examine the effect of xanthan gum on the soil strength and plasticity. Additionally, the durability of biopolymer-treated and untreated soils under wetting and drying cycles and moisture susceptibility were assessed. The results showed that the compressive strength of soil increased by increasing the xanthan gum concentration and curing time and reached its peak value after a specific curing time. The addition of xanthan gum resulted in significant improvement in soil cohesion and caused a reduction in the internal friction angle of the soil. While increasing the number of wetting/drying cycles decreased the soil strength, the biopolymer-treated soil exhibited higher soil strength than the untreated soil. This study provides valuable experiences in the use of xanthan gum biopolymer in practical engineering applications.

We report on the temperature dependence of the charge transport and activation energy of amorphous silicon carbide (a-SiC) thin films grown on quartz by low-pressure chemical vapor deposition. The electrical conductivity as characterized by the Arrhenius rule was found to vary distinctly under two activation energy thresholds of 150 and 205 meV, corresponding to temperature ranges of 300 to 450 K and 450 to 580 K, respectively. The a-SiC/quartz system displayed a high temperature coefficient of resistance ranging from −4,000 to −16,000 ppm/K, demonstrating a strong feasibility of using this material for highly sensitive thermal sensing applications. [ABSTRACT FROM AUTHOR]