Organic Matrix Research Articles

High-agronomic value of selected poultry manure valorized through aerobic fermentation: The AFRODITE® process

Chicken manure is a raw material with potential value as fertilizer. The present work documented an 8-month continuous spontaneous fermentation process, referred to as AFRODITE® (Aerobic Fermentation and Revaluation of Organic matrix to Develop and Improve The Essence of soil), where the main physical, chemical and microbiological parameters have been investigated for two years within the company FOMET S.p.A. The pelletized final product reached in both years stable value of pH (6.5–7.5), moisture (17.0–13.8%), total nitrogen (3.0–3.8%) and C/N ratio (10.46–10.66); total eubacteria population decreased (from 10 to 11 to about 7 Log CFU/g), with the selection of a thermophilic/hyperthermophilic microbiota due to the high temperatures during the process. The commercial product is microbiologically safe and rich of bacteria that were isolated and identified. The dominant species belong to the Bacillus genus, which includes several Plant Growth Promoting Rhizobacteria whose beneficial activities towards soil and plant are widely known. A greenhouse experiment in lettuce and eggplants showed the positive effect of two concentrations of the pelletized commercial product (2.5 and 5% w/w) in combination with a mixture of topsoil/river sand. In particular, 27% of fresh weight increase was observed in lettuce with both product amounts whereas the average production of eggplants was three times higher using 5% pelletized product compared to the untreated control. This work has highlighted that chicken manure fermentation followed by pelletization allows the obtainment of a stable product, rich in beneficial bacteria and nutritional elements, possessing growth-promoting effects on horticultural plants. The process represents a virtuous example of circular economy.

Chitosan as a Templating Agent of Calcium Phosphate Crystalline Phases in Biomimetic Mineralization: Theoretical and Experimental Studies.

Highlighting the essential role of chitosan (CS), known for its biocompatibility, biodegradability, and ability to promote cell adhesion and proliferation, this study explores its utility in modulating the biomimetic mineralization of calcium phosphate (CaP). This approach holds promise for developing biomaterials suitable for bone regeneration. However, the interactions between the CS surface and in situ precipitated CaP still require further exploration. In the theoretical section, molecular dynamics (MD) simulations demonstrate that, at an appropriate pH level during the prenucleation stage, calcium ions (Ca2+) and hydrogen phosphate ions (HPO42-) form Posner-like clusters. Additionally, the interaction between these clusters and the CS molecule enhances system stability. Together, these phenomena facilitate the transition to subsequent heterogeneous nucleation on the surface of the organic matrix, which is a more controlled process than homogeneous nucleation in solution. Dynamic simulation results suggest that CS acts as a stabilizing matrix at pH 8.0 during biomimetic mineralization. In the experimental section, the effects of pH and the molecular weight of CS were investigated, with a focus on their impact on the crystal structure of the resulting material. X-ray diffraction and scanning electron microscopy analyses reveal that, under conditions of approximately pH 8.0 and a CS molecular weight of 20 000 g/mol, and controlled ion concentration, ultrasound radiation, and temperature, the dominant CaP phases in the material are carbonate-doped hydroxyapatite (CHA) and octacalcium phosphate (OCP). These findings suggest that CS, when adjusted for molecular weight and pH, facilitates the formation of CaP crystal phases that closely resemble the natural inorganic composition of bone, highlighting its protective and regulatory roles in the growth and maturation of crystals during mineralization. The theoretical predictions and experimental outcomes confirm the crucial role of CS as a templating agent, enabling the development of a biomimetic mineralization pathway. CS's ability to guide this process may prove valuable in the design of materials for bone tissue engineering, particularly in developing effective materials for bone tissue healing and regeneration.

Modeling of the tunable plasmonic properties of spherical and ellipsoidal silver nanoparticles in the matrix of an organic semiconductor

The object of research is the tunable plasmonic properties of spherical and ellipsoidal silver nanoparticles in the organic semiconductor matrix. The average absorption cross-sections, scattering cross-sections, and optical radiation efficiency of spherical and ellipsoidal silver nanoparticles have been simulated. The long-wave statistical approach has been used to model the optical parameters of the assembled spherical and ellipsoidal nanoparticles. Statistical averaging is used here, where absorption and scattering are considered from an «effective» particle with statistical properties. This approach avoids complex calculations considering the details of the spectral characteristics of single nanoparticles of different shapes. Taking into account the fact that the nanocomposite matrix will contain ensembles of spherical nanoparticles of different sizes, the peak of their absorption and scattering cross sections will be shifted to the short wavelength region of the spectrum compared to ensembles of the same spherical nanoparticles. In addition, there is a slight increase in the absorption cross-section and a decrease in the scattering cross-section, confirming the presence of smaller nanoparticles. A study was made of a composite material containing a randomly dispersed ensemble of silver ellipsoidal nanoparticles of the same and different shapes and sizes in an organic semiconductor matrix. An ensemble of identical ellipsoidal nanoparticles is characterized by the presence of two plasmon peaks, which corresponds to the characteristics of a single ellipsoidal nanoparticle. A completely different situation is observed if to consider that the nanocomposite will contain an ensemble of ellipsoidal nanoparticles of different shapes and sizes. Such nanoparticles will be characterized by a plasmon peak for both the absorption and scattering cross-sections. This can be explained by the fact that as the size of ellipsoidal nanoparticles decreases, the distance between the peaks responsible for the longitudinal and transverse modes of plasmon excitation decreases. An increase in the shape distribution leads to a broadening of the absorption and scattering cross-section spectra. The efficiency of the optical radiation increases as the size distribution increases. It is shown that a change in the refractive index of an organic semiconductor matrix mainly affects only the value of the scattering cross-section of an ensemble of ellipsoidal nanoparticles dispersed in it. This research is a preliminary step to studying the influence of these particles on the properties of organic light-emitting structures.

The Deposition of Hydroxyapatite Particles Within an Organic Matrix on the Surface of Poly(lactic acid).

Hydroxyapatite (HAP) is a well-established material in biomedical applications, especially for bone tissue regeneration, dental implants, and drug delivery systems. Recent research emphasizes enhancing the biocompatibility and osteoconductivity of orthopedic implants using HAP. This study explores the potential of combining HAP with a lipid matrix to improve the surface properties and biocompatibility of poly(lactic acid) (PLA)-based, 3D-printed, resorbable bone implants. We utilized the Langmuir-Blodgett method to deposit HAP within a dihexadecyl phosphate (DHP) matrix onto PLA substrates. This study demonstrates that DHP and HAP form stable monolayers at the air/water interface with HAP particles distributed within a homogeneous lipid matrix. The presence of HAP and the resulting changes in surface free energy (SFE) are hypothesized to enhance the biocompatibility of PLA implants. Our findings indicate that films composed of DHP + HAP 5:1 are particularly effective in altering PLA surface characteristics, potentially improving osteointegration, and reducing microbial adherence. Overall, this work highlights that surface modification of PLA with HAP and lipid matrices is the first step towards new, promising, and cost-effective strategies for developing advanced biomaterials for bone regeneration.

Comparative Assessment of a Light-Curable Dental Composite Reinforced with Artificial Fibers.

FRCs (Fiber-Reinforced Composites) are materials that are being used increasingly more often in dentistry as an alternative to traditional restorations made of ceramics or metals. The aim of this study was to carry out a comparative analysis of the strength parameters of a light-curable dental composite reinforced with one single band and two single bands of artificial fibers. The specimens for the strength tests were prepared in accordance with the guidelines of the PN-EN ISO 4049:2019-07 international standard. The test material covered specimens of composite reinforced with single (one or two) bands of fibers. The following bands of fibers were used: carbon (WGL), aramid (AMD) and hybrid carbon-aramid (WGL-AMD). The presence of one single band of aramid fibers caused a three-fold increase in deflection, with a simultaneous increase in the Young's modulus of over 140%. The flexural strength of specimens reinforced with one single band of aramid fibers was higher by 280% than that control group specimens (KONT). To summarize the performed tests, the incorporation of carbon, aramid and hybrid carbon-aramid fibers into organic matrix has a significant impact on the values of the mechanical parameters of dental composites. The results indicate that particular attention should be paid to aramid fibers, which have rarely been used in dentistry so far.

To date or not to date? A comparison of different 14C pretreatment methods applied to archeological marine shells from Vale Boi (Portugal)

Abstract Mollusk shells are often found in archeological sites, given their great preservation potential and high value as a multipurpose resource, and they can often be the only available materials useful for radiocarbon (14C) dating. However, dates obtained from shells are often regarded as less reliable compared to those from bones, wood, or charcoals due to different factors (e.g., Isotope fractionation, reservoir effects etc.). The standard acid etching pretreatment for mollusk shells is the most used in many 14C laboratories, although another protocol known as CarDS (Carbonate Density Separation) was introduced just over a decade ago. We compare these two methods with two newly proposed methods for intracellular organic matrix extraction. We applied all four methods to samples selected from different archeological layers of the well-known Upper Paleolithic site of Vale Boi, rich in mollusk specimens throughout the stratigraphic sequence. Here we compare our results to previous dates to determine which of these pretreatment methods results in the most reliable 14C dates. Based on the results of this study, all four methods gave inconsistent ages compared to previous dates and the stratigraphic attribution.

Mitigation of Fluoride Contamination in Drinking Water Supply Sources by Adsorption Using Bone Char: Effects of Mineral and Organic Matrix

This study focused on fluoride (F−) contamination of water sources in Bahimi village, Cameroon. After the first investigation, results revealed that all water samples collected had elevated concentrations of fluoride ions (2.3 ± 0.1) mg/L to (4.5 ± 0.2) mg/L above the WHO guidelines (less than 1.5 mg/L). To mitigate the F− levels, the use of bone char (BC) as an adsorbent material was proposed and its performance was tested. BC was prepared from bovine bones at different calcination temperatures (350 °C, 450 °C, 550 °C and 650 °C) and residence times (1 h and 2 h). The prepared materials were characterized in detail by SEM/EDS, BET, FTIR, and XRD. The BET findings indicated that the surface area of BC samples decreased with increasing calcination temperature and residence time. At a lower heating temperature and holding time (350 °C, 1 h), the prepared BC exhibited a higher specific surface area (112.3 ± 0.3) m2/g and adsorption capacity for F− in the sampled water. Also, the batch adsorption experiments showed that the optimized adsorbent dose of 8 g/L facilitates the reduction in the F− level of the sampled water below the acceptable limit level (1.5 mg/L) within 5 min of treatment. The presence of Ca2+ and Mg2+ in natural water has a positive effect on the removal of F− in BC resulting in a high adsorption performance range of (72.5 ± 1.4)% to (80.3 ± 0.6)%. It was found that the adsorption of Ca2+ on the BC surface occurs via cation exchange with Na+. However, an increase in dissolved organic carbon (DOC) in the treated water limited the application of BC. Overall, the study presented a cost-effective adsorbent for the removal of this recalcitrant ion in the water source.

Enamel hypoplasia: A defect in the organic matrix

Enamel hypoplasia: A defect in the organic matrix

Exploring the acid-insoluble shell organic matrix of freshwater mussels (Unionoida) as a proxy for palaeodietary and paleoenvironmental studies

ABSTRACT The shells of freshwater mussels, commonly found at archaeological sites associated with the Kodjadermen-Gumelnița-Karanovo VI human groups (5th millennium BCE, Romania and Bulgaria), were a significant dietary component for this population. The organic matrix of these ancient shells is often well-preserved and can be analysed using stable isotopes. This study establishes the empirical relationship between the isotopic composition of the acid-insoluble shell organic matrix (AIM) and the soft tissues of modern Unio tumidus. A quality criterion for AIM (C:N ratio 3.6 (3.3–<3.8)) was defined, and isotopic offsets (Δ15NAIM-defatted body = +0.95‰, Δ13CAIM-defatted body = +0.93‰ for soft tissues; Δ15NAIM-muscle = +1.7‰, Δ13CAIM-muscle = +0.3‰ for the adductor muscle) were determined. Our data suggest that the Gumelnița mussels were omnivorous, with a similar trophic level to carp and pond turtles, sourced from diverse water bodies (rivers, lakes …) based on δ13C values.

A Hollow Hemispherical Mixed Matrix Lithium Adsorbent with High Interfacial Interaction for Lithium Recovery from Brine

Mixed matrix lithium adsorbents have attracted much interest for lithium recovery from brine. However, the absence of an interfacial interaction between the inorganic lithium-ion sieves (LISs) and the organic polymer matrix resulted in the poor structural stability and attenuated lithium adsorption efficiency. Here, a novel hollow hemispherical mixed matrix lithium adsorbent (H-LIS) with high interfacial compatibility was constructed based on mussel-bioinspired surface chemistry using a solvent evaporation induced phase transition method. The effects of types of functional modifiers, LIS loading amount, adsorption temperature and pH on their structural stability and lithium adsorption performance were systematically investigated. The optimized H-LIS adsorbent with the LIS loading amount of 50 wt.% possessed the structural merit that the LIS functionally modified by dopamine exposed on both the inner and outer surfaces of the hollow hemispheres. At the best adsorption pH of 12.0, it showed a comparable lithium adsorption capacity of 25.68 mg·g−1 to the powdery LIS within 4 h, favorable adsorption selectivity of Mg/Li and good reusability that could maintain over 90% of lithium adsorption capacity after the LiCl adsorption—0.25 M HCl pickling-DI water cleaning cycling processes for three times. The interfacial interaction mechanism of H-LIS for lithium adsorption was innovatively explored via advanced microcalorimetry technology. It suggested the nature of the Li+ adsorption process was exothermic and dopamine modification could reduce the activation energy for lithium adsorption from 15.68 kJ·mol−1 to 13.83 kJ·mol−1 and trigger a faster response to Li+ by strengthening the Li+-H+ exchange rate, which established the thermodynamic relationship between the structure and Li+ adsorption performance of H-LIS. This work will provide a technical support for the structural regulation of functional materials for lithium extraction from brine.

Evolution of mechanical properties of organic-rich shale during thermal maturation

Accurate assessment of the mechanical properties of organic matter, clay matrix, and bulk shale during maturation remains a challenge. Here, we aim to assess the mechanical properties of organic-rich shale during maturation using a combination of nanoindentation methods and various geochemical analyses, i.e., mineral composition, mass loss rate, chemical structure of organic matter, and Rock-Eval analyses. Results show that the evolution of mechanical properties of organic matter in shale during maturation can be divided into: the main oil-generation stage, and the condensate oil and gas generation stage. The stiffening of organic matter in the shale is mainly due to increased aromaticity and condensation of aromatic groups. The clay matrix experiences a slight decrease in hardness and Young’s modulus at low maturity levels due to the generation of liquid hydrocarbons. However, overall, the clay matrix becomes stiffer as the shale matures due to shale dehydration, expulsion or cracking of liquid hydrocarbons, transformation of clay minerals, and hardening of organic matter. The Young’s modulus and hardness of bulk shale generally increase with increasing maturity. This is closely related to the hardening of organic matter and clay matrix, as well as the development of the more compact and dense microstructure in the shale.

Gene expression microarray analysis during metamorphosis and early calcification in the scleractinian coral Acropora millepora

ABSTRACT In the face of global warming and ocean acidification, understanding the cellular mechanisms underlying coral metamorphosis and early calcification is essential, as both processes are likely to be affected by a changing environment. In this study, we used cDNA microarray expression analysis to compare transcription profiles between four distinct life stages in the ‘complexa’ coral Acropora millepora: 1) aposymbiotic non-calcifying planula, 2) aposymbiotic calcifying flat polyp, 3) aposymbiotic calcifying primary polyp and 4) symbiotic adult tip. Highly up-regulated genes in planulae were molecules involved in calcium signalling, lipid metabolism and development. Transcripts up-regulated in post-settlement juvenile stages regulate tissue morphogenesis, cell division and responses to oxidative stress. Transcripts with the highest expression in adult polyps are involved in responses to abiotic stimuli and asexual reproduction. Transcripts up-regulated in calcifying stages included carbonic anhydrases and organic matrix components. Additionally, our results suggest an overlap between intracellular secondary messengers following settlement and metamorphosis. A subset of fluorescent proteins were up-regulated at the planula stage but down-regulated after settlement, supporting the idea that these molecules might have a role in quenching reactive oxygen species. Altogether, our results suggest that Acropora developmental stages are transcriptionally distinct units in which transcription profiles reflect responses to different physiological and ecological conditions.

Organic-Inorganic Hybrid Materials from Vegetable Oils.

The production of materials based on fossil resources is yielding more sustainable and ecologically beneficial methods. Vegetable oils (VO) are one example of base materials whose derivatives rival the properties of their petro-based counterparts. Gaps exist however and one way to fill them is by employing sol-gel processes to synthesize organic-inorganic hybrid materials, often derived from silane/siloxane compounds. Creating Si─O─Si inorganic networks in the organic VO matrix permits the attainment of necessary strength, among other property enhancements. Consequently, many efforts have been directed to optimally achieve organic-inorganic hybrid materials with VOs. However, compatibilization is challenging, and desirable conditions for matching the inorganic filler in the organic matrix remain a key stumbling block toward wider application. Therefore, this review aims to detail recent progress on these new hybrids, focusing on the main strategies to polymerize and functionalize the raw VO, followed by routes highlighting the addition of the inorganic fillers to obtain desirable composites.

Perfluoroalkyl acid precursor or weakly fluorinated organic compound? A proof of concept for oxidative fractionation of PFAS and organofluorines.

Organofluorine mass balance approaches are increasingly applied to investigate the occurrence of per- and polyfluoroalkyl substances (PFAS) and other organofluorines in environmental samples more comprehensively. Usually, complex samples prevent the identification and quantification of every fluorine-containing molecule. Consequently, large unidentified fractions between fluorine sum parameters such as extractable organic fluorine (EOF) and the sum of quantified analytes are frequently reported. We propose using oxidative conversion to separate (unidentified) weakly fluorinated compounds (e.g., pesticides, pharmaceuticals) from PFAA-precursors (perfluoroalkyl chain lengths ≥ C6). We show with three organofluorine model substances (flufenamic acid, diflufenican, pantoprazole) that CF3-groups or aromatic fluorine can be quantitatively converted to inorganic fluoride and trifluoroacetic acid (TFA) by applying PhotoTOP oxidation (UV/TiO2). The principle of fluorine separation in mixtures is demonstrated by the oxidation of the three weakly fluorinated compounds together with the PFAA-precursor 6:2/6:2 fluorotelomer mercaptoalkyl phosphate diester (FTMAP). After oxidation, the products F- and TFA were separated from PFCAs (> C4) by SPE, and the fractions were analyzed individually. Closed mass balances both with and without the addition of organic matrix were achieved. Eventually, the fluorine balance was verified by total fluorine measurements with combustion ion chromatography (CIC). The proposed methods should be considered a proof of concept to potentially explain unidentified fractions of the EOF, especially if compounds with low fluorine content such as pesticides, pharmaceuticals, and their transformation products contribute largely to the EOF. Future studies are needed to show the applicability to the complexity of environmental samples.

Pepgen-P15 delivery to bone: A novel 3D printed scaffold for enhanced bone regeneration

Pepgen-P15 is a combination of an organic hydroxyapatite matrix derived from bovine sources, combined with a synthetic peptide known as P-15. The interaction between α2β1 integrin and the P15 chain triggers both intracellular and extracellular signaling pathways, resulting in the production of growth factors. Three-dimensional (3D) printing has recently emerged as an innovative strategy for developing personalized therapies in bone tissue regeneration. In this research, various ratios of calcium magnesium silicate (bredigite) nanoparticles were used to modify 3D printed scaffolds made of xanthan gum and polycaprolactone (PCL) via fused deposition modeling (FDM). Scaffolds were subsequently treated with an alkaline solution, covered with graphene oxide, and finally, Pepgen-P15 was applied. the effects of xanthan gum were assessed using swellability and contact angle tests. The results indicated that, the prepared scaffolds exhibited suitable degradation rates, mechanical characteristics, and apatite formation. Alizarin red and alkaline phosphatase assays were also conducted to evaluate the scaffolds’ effectiveness in promoting bone cell differentiation during cell culture. Furthermore, the surface of the scaffold was examined to determine the amount of Pepgen-P15 loaded and released. According to the findings, the scaffold composed of 20 % bredigite and 0.3 % graphene oxide, coated with Pepgen-P15, demonstrate optimal mechanical properties, cell adherence, development, and proliferation. Typically, it is a good candidate for use in bone tissue engineering.

Effect of replacing Bis-GMA with a biobased trimethacrylate on the physicochemical and mechanical properties of experimental resin composites.

To analyze the incorporation of cardanol trimethacrylate monomer (CTMA), derived from the cashew nut shell liquid, as a substitute for Bis-GMA in acrylic resins formulations and its effect on experimental resin composites' physicochemical and mechanical properties. The intermediary cardanol epoxy was synthesized via cardanol epoxidation, followed by the synthesis of CTMA through methacrylic anhydride solvent-free esterification. Experimental resin composites were formulated with an organic matrix composed of Bis-GMA/TEGDMA (50/50 wt %) (control). CTMA was gradually added to replace different proportions of Bis-GMA: 10 wt % (CTMA-10), 20 wt % (CTMA-20), 40 wt % (CTMA-40), and 50 wt % (CTMA-50). The composites were characterized by degree of conversion, water sorption and solubility, viscosity, thermogravimetric analysis, dynamic mechanical analysis, flexural strength and elastic modulus. Data were analyzed with one-way ANOVA and Tukey's post-hoc test (α = 0.05), except for water sorption data, which were analyzed by Kruskall-Wallis and Dunn's method. CTMA-based and control composites did not show statistically significant differences regarding degree of conversion, flexural strength and elastic modulus. CTMA reduced the viscosity and solubility compared to the Bis-GMA-based composite. The CTMA-40 and CTMA-50 exhibited significantly lower water sorption compared to the control. Also, acceptable thermal stability and viscoelastic properties were obtained for safe use in the oral cavity. Incorporating CTMA into composites resulted in similar chemical and mechanical properties compared to Bis-GMA-based material while reducing viscosity, water sorption and solubility. CTMA could be used as a trimethacrylate monomer replacing Bis-GMA in resin composites, thereby minimizing BPA exposure.

Wave-transparent and eco-friendly flame-retardant phosphorus-based phthalonitrile/quartz composites by a synchronized self-curing strategy with cyano and alkynyl groups

The robust human–machine interaction systems of the aerospace industry necessitate the development of thermal resistant wave-transparent composites, with a pivotal focus on organic resin matrix. However, enhancing the heat resistance of such materials while preserving other critical attributes has been a formidable challenge. In this study, a novel designed strategy of a dual-curing functional phosphorus-based phthalonitrile monomer (P-ALK-PN) has been proposed. The optimized curing temperatures for intra- or intermolecular Diels-Alder reactions of alkynyl groups and polyaddition reaction of cyano groups resulted in a homogeneous and highly crosslinked N-enriched phthalonitrile system. After curing at 450 °C, the resin, namely P-ALK-PN-450 °C, demonstrated exceptional thermal stability (T5% = 644 °C), thermo-oxidative stability (T5% = 554 °C), and char yield at 800 °C (90.7 % in N2 and 67.5 % in air). Their quartz fiber reinforced composites (P-ALK-PN/QFs) were subsequently fabricated by the hot-pressing process. Upon post-curing at 420 °C, P-ALK-PN-420 °C/QF displayed elevated glass transition temperature (550 °C), flexural strength (319 MPa), and relatively low dielectric properties with a dielectric constant (Dk) of approximately 4.2 and a dissipation factor (Df) less than 0.02 across a wide temperature ranging from 25 °C to 600 °C. Especially, it exhibited excellent flame retardancy (only a 6.7 % weight loss at ambient temperatures exceeding 1300 °C for 200 s) as well, stemming from release of eco-friendly inert gases (NH3) and formation of a graphitized protective layer during pyrolysis. These promising results highlight the potential applications of P-ALK-PN resins in aerospace and high-performance engineering fields.

Preparation of two–dimensional gradient fillers reinforced polymer nanocomposites for high–performance energy storage of dielectric capacitors

The serious interfacial issue between the inorganic filler and the organic matrix in the dielectric nanocomposite results in a low electric field breakdown strength (Eb) and low energy density (Ue). In this work, novel KxNa1–xNbO3@ZrO2 (KNN@ZO) nanosheets (NSs) were prepared by coating highly insulated ZO on the ferroelectric two–dimensional (2D) KNN NSs via a chemical precipitation method. As fillers, the KNN@ZO significantly improved the energy storage performances of poly (vinylidene fluoride) (PVDF)–polymethyl methacrylate (PMMA) blends. The highly insulated ZO shell restricts the carrier migration at the filler/polymer interface, thereby reducing the local electric field distortion. By sandwich structural design, a high Ue of 19.8 J/cm3, with a large difference of electrical displacement (8.5 μC/cm2), is measured in KNN@ZO/PVDF–PMMA with 5 % filler content at 528 MV/m. According to the finite element simulation, the 2D morphology and gradient structure can enhance the electric field distribution, and therefore effectively increase the Eb of nanocomposites. The results indicate that the 2D core–shell NSs fillers with gradient dielectric constant represent an effective approach to improve energy storage performance of the polymer–based nanocomposites.

Некоторые аспекты патогенеза мочекаменной болезни.

Introduction. Urolithiasis is a disease whose etiology and pathogenesis have not been fully elucidated. However, studies of recent decades indicate the presence of an organic matrix in the composition of all urinary stone. Materials and methods. A white substance of the consistency of «soft plasticine» was extracted from the pelvis of the right kidney. The sample was examined for elementary composition, molecular weight characteristics and structure. Results. The structure of the sample had a fibrillar structure and was a mixture of various proteins and glycoproteins. The sample extracted from the kidney consists of 70% of inflammatory and transport proteins (myelopyroxidase, immunoglobulin, calprotectin), and 30% is a hard-to-dissolve polymer (polymerized Tamma-Horsfal protein). Conclusions. The formation of large and coral kidney stone can begin with the formation of a «matrix model» consisting of various proteins, mainly involved in inflammation, followed by mineralization and compaction of the stone.

Cu-ZnO Embedded in a Polydopamine Shell for the Generation of Antibacterial Surgical Face Masks.

A new easy protocol to functionalize the middle layer of commercial surgical face masks (FMs) with Zn and Cu oxides is proposed in order to obtain antibacterial personal protective equipment. Zinc and copper oxides were synthesized embedded in a polydopamine (PDA) shell as potential antibacterial agents; they were analyzed by XRD and TEM, revealing, in all the cases, the formation of metal oxide nanoparticles (NPs). PDA is a natural polymer appreciated for its simple and rapid synthesis, biocompatibility, and high functionalization; it is used in this work as an organic matrix that, in addition to stabilizing NPs, also acts as a diluent in the functionalization step, decreasing the metal loading on the polypropylene (PP) surface. The functionalized middle layers of the FMs were characterized by SEM, XRD, FTIR, and TXRF and tested in their bacterial-growth-inhibiting effect against Klebsiella pneumoniae and Staphylococcus aureus. Among all functionalizing agents, Cu2O-doped-ZnO NPs enclosed in PDA shell, prepared by an ultrasound-assisted method, showed the best antibacterial effect, even at low metal loading, without changing the hydrophobicity of the FM. This approach offers a sustainable solution by prolonging FM lifespan and reducing material waste.