Search Results (255)

Background: Local anesthesia is essential for most dental procedures, but its parenteral administration is often painful. Topical anesthetics are commonly used to minimize local anesthesia pain; however, commercial formulations fail to fully prevent the discomfort of local anesthetic injection. Methods: We developed and characterized a novel lidocaine and epinephrine co-loaded liquid crystalline precursor system (LCPS) for topical anesthesia. The formulation was structurally characterized using polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS). Rheological behavior was assessed through continuous and oscillatory rheological analyses. Texture profile analysis, in vitro mucoadhesive force evaluation, in vitro drug release and permeation studies, and an in vivo toxicity assay using the chicken chorioallantoic membrane (CAM) model were also conducted. Results: PLM and SAXS confirmed the transition of the LCPS from a microemulsion to a lamellar liquid crystalline structure upon contact with artificial saliva. This transition enhanced formulation consistency by over 100 times and tripled mucoadhesion strength. The LCPS also provided controlled drug release, reducing permeation flow by 93% compared to the commercial formulation. Importantly, the CAM assay indicated that the LCPS exhibited similar toxicity to the commercial product. Conclusions: The developed LCPS demonstrated promising physicochemical and biological properties for topical anesthesia, including enhanced mucoadhesion, controlled drug delivery, and acceptable biocompatibility. These findings support its potential for in vivo application and future clinical use to reduce pain during dental anesthesia procedures. Full article

An integrated process scheme is developed for valorizing filtered liquid digestates (FLD) from an industrial anaerobic digestion (AD) plant treating dairy-processing effluents with relatively low nutrient concentrations. The process scheme involves FLD treatment by nanofiltration (NF) membranes, followed by struvite recovery from the NF-retentate. An NF pilot unit (designed for this purpose) is combined with a state-of-the-art NF/RO process simulator. Validation of simulator results with pilot data enables reliable predictions required for scaling up NF systems. The NF permeate meets the standards for restricted irrigation and/or reuse. Considering the significant nutrient concentrations in the NF retentate (i.e., ~500 mg/L NH4-N, ~230 mg/L PO4-P), struvite recovery/precipitation is investigated, including determination of near-optimal processing conditions. Maximum removal of nutrients, through production of struvite-rich precipitate, is obtained at a molar ratio of NH₄:Mg:PO₄ = 1:1.5:1.5 and pH = 10 in the treated stream, attained through the addition of Κ₂HPO₄, ΜgCl₂·6H₂O, and NaOH. Furthermore, almost complete struvite precipitation is achieved within ~30 min, whereas precipitate/solid drying at modest/ambient temperature is appropriate to avoid struvite degradation. Under the aforementioned conditions, a significant amount of dry precipitate is obtained, i.e., ~12 g dry mass per L of treated retentate, including crystalline struvite. The approach taken and the obtained positive results provide a firm basis for further development of this integrated process scheme towards sustainable large-scale applications. Full article

4H-silicon carbide (4H-SiC) is a cornerstone for next-generation optoelectronic and power devices owing to its unparalleled thermal, electrical, and optical properties. However, its chemical inertness and low dopant diffusivity for most dopants have historically impeded effective doping. This study unveils a transformative laser-assisted boron doping technique for n-type 4H-SiC, employing a pulsed Nd:YAG laser (λ = 1064 nm) with a liquid-phase boron precursor. By leveraging a heat-transfer model to optimize laser process parameters, we achieved dopant incorporation while preserving the crystalline integrity of the substrate. A novel optical characterization framework was developed to probe laser-induced alterations in the optical constants—refraction index ($\mathrm{n}$) and attenuation index ($\mathrm{k}$)—across the MIDIR spectrum (λ = 3–5 µm). The optical properties pre- and post-laser doping were measured using Fourier-transform infrared spectrometry, and the corresponding complex refraction indices were extracted by solving a coupled system of nonlinear equations derived from single- and multi-layer absorption models. These models accounted for the angular dependence in the incident beam, enabling a more accurate determination of $\mathrm{n}$ and $\mathrm{k}$ values than conventional normal-incidence methods. Our findings indicate the formation of a boron-acceptor energy level at 0.29 eV above the 4H-SiC valence band, which corresponds to λ = 4.3 µm. This impurity level modulated the optical response of 4H-SiC, revealing a reduction in the refraction index from 2.857 (as-received) to 2.485 (doped) at λ = 4.3 µm. Structural characterization using Raman spectroscopy confirmed the retention of crystalline integrity post-doping, while secondary ion mass spectrometry exhibited a peak boron concentration of 1.29 × 10¹⁹ cm⁻³ and a junction depth of 450 nm. The laser-fabricated p–n junction diode demonstrated a reverse-breakdown voltage of 1668 V. These results validate the efficacy of laser doping in enabling MIDIR tunability through optical modulation and functional device fabrication in 4H-SiC. The absorption models and doping methodology together offer a comprehensive platform for paving the way for transformative advances in optoelectronics and infrared materials engineering. Full article

Polyphenylene sulfide (PPS)-based separators have garnered significant attention as high-performance components for next-generation lithium-ion batteries (LIBs), driven by their exceptional thermal stability (>260 °C), chemical inertness, and mechanical durability. This review comprehensively examines advances in PPS separator design, focusing on two structurally distinct categories: porous separators engineered via wet-chemical methods (e.g., melt-blown spinning, electrospinning, thermally induced phase separation) and nonporous solid-state separators fabricated through solvent-free dry-film processes. Porous variants, typified by submicron pore architectures (<1 μm), enable electrolyte-mediated ion transport with ionic conductivities up to >1 mS·cm⁻¹ at >55% porosity, while their nonporous counterparts leverage crystalline sulfur-atom alignment and trace electrolyte infiltration to establish solid–liquid biphasic conduction pathways, achieving ion transference numbers >0.8 and homogenized lithium flux. Dry-processed solid-state PPS separators demonstrate unparalleled thermal dimensional stability (<2% shrinkage at 280 °C) and mitigate dendrite propagation through uniform electric field distribution, as evidenced by COMSOL simulations showing stable Li deposition under Cu particle contamination. Despite these advancements, challenges persist in reconciling thickness constraints (<25 μm) with mechanical robustness, scaling solvent-free manufacturing, and reducing costs. Innovations in ultra-thin formats (<20 μm) with self-healing polymer networks, coupled with compatibility extensions to sodium/zinc-ion systems, are identified as critical pathways for advancing PPS separators. By addressing these challenges, PPS-based architectures hold transformative potential for enabling high-energy-density (>500 Wh·kg⁻¹), intrinsically safe energy storage systems, particularly in applications demanding extreme operational reliability such as electric vehicles and grid-scale storage. Full article

Bacterial cellulose (BC) is a highly pure and crystalline cellulose produced via bacterial fermentation. However, due to its chemical structure made of strong hydrogen bonds and its high molecular weight, BC can neither be melted nor dissolved by common solvents. Therefore, processing BC implies the use of very strong, often toxic and dangerous chemicals. In this study, we proved a green method to produce electrospun BC fibers by testing different ionic liquids (ILs), namely, 1-butyl-3-methylimidazolium acetate (BmimAc), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EmimTFSI) and 1-ethyl-3-methylimidazolium dicyanamide (EmimDCA), either individually or as binary mixtures. Moreover, γ-valerolactone (GVL) was tested as a co-solvent derived from renewable sources to replace dimethyl sulfoxide (DMSO), aimed at making the viscosity of the cellulose solutions suitable for electrospinning. A BmimAc and BmimAc/EmimTFSI (1:1 w/w) mixture could dissolve BC up to 3 w%. GVL was successfully applied in combination with BmimAc as an alternative to DMSO. By optimizing the electrospinning parameters, meshes of continuous BC fibers, with average diameters ~0.5 μm, were produced, showing well-defined pore structures and higher water absorption capacity than pristine BC. The results demonstrated that BC could be dissolved and electrospun via a BmimAc/GVL solvent system, obtaining ultrafine fibers with defined morphology, thus suggesting possible greener methods for cellulose processing. Full article

This report discusses the impact of nanoparticles on glass-forming systems composed of a liquid crystalline (LC) mixture E7 and paraelectric BaTiO₃ particles ($d\approx 50 \mathrm{n}\mathrm{m}$, globular), tested via broadband dielectric spectroscopy. In the isotropic phase, critical changes in the dielectric constant are shown. They are related to the weakly discontinuous nature of the isotropic–nematic transition. In the nematic phase, two primary relaxation times/processes and DC electric conductivity are considered, down to the glass temperature $T_g$. The prevalence of portrayals via the ‘double exponential’ MYEGA equation and the critical & activated Drozd-Rzoska relation for dynamic properties are shown. For the primary loss curve, critical-like changes of its maximum (peak) are evidenced: ${\epsilon }_{peak}^{″}\propto 1/\left(T-T_g^{*}\right)$ for $T_g<T<\left(T_g+25 \mathrm{K}\right)$, where $T_g^{*}<T_g$ denotes the extrapolated singular temperature. Dielectric constant monitoring revealed the permanent arrangement of rod-like LC molecules by nanoparticles’ endogenic impact in the nematic phase. The heuristic model regarding this unique behavior is presented. It considers a hypothetical link between the glass transition and a hidden near-critical discontinuous phase transition, uniquely avoiding a symmetry change. The uniaxiality of LC molecules enables the detection of critical-like features when approaching the glass transition, hypothetically associated with a specific ‘amorphous’ phase transition. Full article

Background: Various routes of drug administration are available for psoriasis treatment. However, there is an urgent need for novel and improved therapeutic options. Hence, our study aimed to develop a nanostructured lipid carrier (NLC) gel of hesperidin (HPD) using a systemic QbD approach for an effective treatment of psoriasis. Methods: Initially, HPD-NLC was optimized with independent variables (drug content, amount of liquid lipid, total lipid, and surfactant concentration) using Box–Behnken Design to assess dependent variables (particle size, size distribution, and entrapment efficiency). HPD-NLC was developed using the high-shear homogenization technique. The characteristics of nanoformulation such as particle size, morphology [transmission electron microscopy (TEM) and differential scanning calorimetry (DSC)], crystallinity [powder X-ray diffraction (XRD)], and chemical interactions [Fourier transform infrared spectroscopy (FTIR)], the drug entrapment efficiency (%EE), and the drug release were investigated. Franz-diffusion cell was utilized to perform in vitro diffusion study, and an imiquimod-induced psoriasis model was used for in vivo study. Results: The optimized HPD-NLC exhibited a spherical shape with particle size of 125.7 nm, polydispersity index (PDI) of 0.36, and entrapment efficiency of 52.26% w/w. Further, different techniques validated the reduced crystallinity of the hesperidin. The in vitro diffusion study highlighted the sustained and anomalous diffusion of the drug from NLC gel. In the in vivo study, the HPD-NLC-Gel-treated group displayed normal skin with minimal keratosis, while the drug-loaded gel group exhibited signs of hyperkeratosis and parakeratosis signs. Conclusions: HPD-NLC gel showed promising advancement in nanotechnology-based psoriasis treatment and the results of this study open the door for the application of topical HPD-NLC-Gel clinically. Full article

Tegoprazan is a potassium ion-competitive acid blocker (P-CAB) and a novel inhibitor of gastric acid secretion. The compound exists in two crystalline polymorphs, A and B, whose structures had not previously been reported. In this study, both polymorphs were analyzed by liquid- and solid-state NMR, revealing identical tautomeric states. Using this information, the crystal structures were determined from laboratory powder X-ray diffraction data by simulated annealing and Rietveld refinement. Both forms were found to crystallize in the monoclinic space group P2₁, with Z = 4 and two independent molecules in the asymmetric unit (Z′ = 2). To assess the stability and reliability of the refined structures, we attempted geometry optimization and vibrational analysis using DFT-D methods. However, due to the high conformational complexity of Z′ = 2 systems, these calculations failed to converge or produced imaginary frequencies. Instead, single-point energy calculations were performed on the refined models. The resulting relative energy differences, together with solubility data, van’t Hoff enthalpies, and DSC profiles, consistently indicated that Polymorph A is more stable than Polymorph B. These results highlight the challenges of structure validation via DFT-D for complex molecular crystals and demonstrate the value of integrating experimental and computational approaches for polymorph characterization. Full article

Cotton fiber, renewable natural cellulose, make up the largest portion of textile waste. The ionic liquid method has been successfully employed to regenerate waste colored cotton fabric in this study, offering a comprehensive approach to the recycling of waste cotton. The chemical recovery process for reclaimed cellulose materials is crucial for high-value recycling of waste cotton fabrics. In this study, waste and new, colored and white cotton fabrics were used as experimental subjects. The breaking strength, degree of polymerization, iodine adsorption equilibrium value, and crystallinity between old and new fabrics were investigated. Ionic liquid 1-allyl-3-methylimidazole chloride ([AMIM]Cl) and zinc chloride (ZnCl₂) were selected to dissolve decolorized waste cotton fabric. Optimal conditions for dissolving the fabric using [AMIM]Cl were investigated. The best dissolution conditions identified were DMSO at a ratio of 1:1 with a dissolution temperature of 110 °C over a duration of 120 min. Additionally, the optimal film formation parameters included a solution concentration of 6%, solidification time of 3 min, and solidification bath temperature of 0 °C. Regenerated cellulose films from both the ionic liquid system (A-film) and zinc chloride system (Z-film) were prepared. The characteristics of the film produced using the most advanced technology were systematically investigated and evaluated. The results of this study provide a crucial theoretical foundation for the recovery and regeneration of waste cotton fabrics. Full article

This study developed a solid self-nanoemulsifying drug delivery system (S-SNEDDS) to improve the oral bioavailability of poorly soluble carvedilol using mesoporous silica nanoparticles (MSNs). The liquid self-nanoemulsifying drug delivery system (L-SNEDDS) consisted of carvedilol, Peceol, Tween 80, and Labrasol in a weight ratio of 10:25:50:25. The liquid SNEDDS was suspended in MSN at various ratios and spray-dried to produce S-SNEDDS. The emulsion size, PDI, solubility, and dissolution of various ratios of MSN were evaluated to make the optimal S-SNEDDS. The optimal S-SNEDDS, manufactured using a ratio of MSN to L-SNEDDS 1000 at 500, formed a nanoemulsion and achieved efficient supersaturation compared to carvedilol alone, which significantly improved drug solubility (approximately 400 times), dissolution (approximately 5.7 times at 60 min), area under the curve (AUC) (21.7 times), and maximum plasma concentration (Cmax) (15.7 times). In addition, the physicochemical properties of the optimal S-SNEDDS were evaluated by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), particle size, and scanning electron microscopy (SEM) images. S-SNEDDS showed a smaller particle size than MSN alone, and the crystalline drug was transformed into an amorphous substance, resulting in encapsulation in MSN. These results suggest that MSN can be a novel biocompatible carrier contributing to a safer and more effective delivery system. Full article

Salt lakes are a rich source of metals used in various fields. Rubidium is found in small amounts in salt lakes, but extraction technology on an industrial scale has not been developed completely. Clathrate hydrates are crystalline compounds formed by the encapsulation of guest molecules in cage-like structures made of water molecules. One of the most important properties for engineering practices of hydrate-based technologies is the comprehension of the phase equilibrium conditions. Phase equilibrium conditions of CO₂ hydrate in rubidium chloride aqueous solution with mass fractions of 0.05, 0.10, 0.15 and 0.20 were experimentally investigated in the pressure range from 1.27 MPa to 3.53 MPa, and the temperature was from 268.7 K to 280.6 K. The measured equilibrium temperature in this study decreased roughly in proportion to the concentration of the RbCl solution from the pure water system. This depression is due to the lowering of the chemical potential of water in the liquid phase by the dissolution of RbCl. Experimental results compared with other salt solution + CO₂ hydrate systems showed that the equilibrium temperatures decreased to a similar degree for similar mole fractions. Full article

Arsenic (As) contamination in water poses significant environmental and health risks, particularly in mining regions. Scorodite (FeAsO₄·2H₂O) is a highly stable compound for As immobilization, traditionally synthesized under high As concentrations and extreme conditions, such as elevated temperatures and pressures. This study explores a sustainable alternative by utilizing Fe-sludge, a waste by-product from acid mine drainage (AMD) treatment, as a novel Fe source for biogenic scorodite formation mediated by the thermo-acidophilic archaeon Acidianus brierleyi. Through a systematic evaluation of Fe-sludge incorporation, the study investigates its impact on microbial activity, As immobilization efficiency, and scorodite crystallization mechanisms. Liquid and solid analyses demonstrate that Fe-sludge enhances the reaction rate and crystallinity of scorodite while bypassing the induction period required in Fe²⁺-only systems. Cross-sectional SEM imaging and EXAFS analysis reveal dynamic transformations on the Fe-sludge surface, supporting faster As adsorption and scorodite nucleation through Fe-S intermediates. Despite potential challenges to microbial activity at higher Fe-sludge concentrations, optimized conditions successfully balance cell viability and Fe utilization. This approach offers an eco-friendly, cost-effective pathway for As immobilization by repurposing AMD sludge, contributing to sustainable resource management and reducing environmental impact. Full article

The morphology of wheat starch granules with different damaged starch (DS) content was analyzed using a particle size analyzer and scanning electron microscopy (SEM); the granular structure was studied using FT-IR spectroscopy and X-ray diffraction (XRD); and the granule–water interaction was evaluated by thermogravimetric analysis (TGA) and dynamic vapor sorption (DVS). The increase in the level of DS shifted the population of B-type granules towards larger particle diameters and shifted the population of A-type granules towards smaller particle diameters. The appearance of the surface of the starch-damaged granules was rough and flaky (SEM images). Crystallinity reductions were related to higher mechanical damage levels of the granular structure (FT-IR and XRD). Higher DS increased the liquid-water absorption capacity of the granules. Higher DS was associated with increments in less-bound water proportions and reductions in more strongly bound water proportions and related to reductions in the evaporation temperature of these water populations (TGA analyses). Concerning DVS data, the results suggested that the driving force for water–monolayer attachment to the starch granules decreased as DS increased. Therefore, it was suggested that the changes in granule structure led to a weaker water–starch polymer chain interactions due to the increase in DS. The results contribute to a better understanding of the influence of mechanical damage on the starch granular structure, which could be related to the rheological and thermal behavior of starch-based systems with different DS. Full article

Pimozide is a first-generation antipsychotic used in the treatment of schizophrenia, Gilles de la Tourette syndrome, and other chronic psychoses. Its in vivo efficacy is limited by poor solubility and consequent poor bioavailability. Therefore, adipic acid was used as a coformer for the preparation of a binary product with improved pharmaceutical properties. The thermal behavior of the liquid-assisted grinding products of compositions included in the range 0.1 < X_PMZ < 0.9 has been interpreted using a thermo-dynamic model according to which the two components originate a new crystalline entity in molar ratio pimozide:adipic acid 0.66:0.33, which forms an eutectic system with adipic acid. The model was confirmed using the quantitative analysis of the melting peaks and using the X-ray diffraction measurements from powders and single crystals. In particular, the latter have demonstrated that the new entity resulting from the pimozide:adipic acid 0.66:0.33 composition is actually salt [PMZH]₂[adipate]. The crystalline product was characterized, from a pharmaceutical perspective, in terms of solubility and wettability (contact angle). Then, a tablet formulation was developed, and its dissolution behavior was compared to a commercial product considered as a reference. The new entity showed improved pharmaceutical properties in terms of solubility and wettability compared to the pure drug in both deionized water and bio-relevant fluids simulating oral administration in fed and fasted conditions. The tablets containing the new crystalline form can make this virtually insoluble drug available for absorption within minutes regardless of the variability in gastric conditions. Full article

The paper presents the results of a comparative microfluidic study of the oil displacement process from a microfluidic chip simulating rock. Suspensions of spherical nanoparticles of silicon oxide (22 nm) and aluminum oxide (11 nm), as well as aluminum oxide nanofibers (8.7 nm in diameter and with an aspect ratio of 58), were used as displacing liquids. The nanofibers represent a unique new-generation crystalline material with a high aspect ratio. This work presents the first consideration of the use of aluminum oxide nanofibers as an additive for enhanced oil recovery. The comparative analysis has demonstrated that the addition of nanofibers can markedly enhance the oil recovery factor relative to the addition of spherical nanoparticles, other things being equal. Thus, in particular, it was demonstrated that the addition of nanofibers into the system allows for the greatest enhancement of the oil recovery factor, reaching a value of 25%, whereas the addition of spherical nanoparticles results in a maximum increment of approximately 10%. This is due to the fact that nanofiber additives have a tenfold stronger effect on the viscosity of nanosuspensions compared to similar additives of spherical particles. Nanosuspensions of aluminum oxide nanofibers exhibit non-Newtonian behavior at low concentrations. This opens the possibility of their extensive use in enhanced oil recovery. Full article