Search Results (16)

The development of sustainable and functional nanocomposites has attracted considerable attention in recent years due to their broad spectrum of potential applications, including wood preservation. Also, a global goal is to reuse the large volumes of waste for environmental issues. In this context, the aim of the study was to obtain soda lignin particles, to graft ZnO nanoparticles onto their surface and to apply these hybrids, embedded into a biodegradable polymer matrix, as protection/preservation coating for oak wood. The organic–inorganic hybrids were characterized in terms of compositional, structural, thermal, and morphological properties that confirm the efficacy of soda lignin extraction and ZnO grafting by physical adsorption onto the decorating support and by weak interactions and coordination bonding between the components. The developed solution based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignin-ZnO was applied to oak wood specimens by brushing, and the improvement in hydrophobicity (evaluated by water absorption that decreased by 48.8% more than wood, humidity tests where the treated sample had a humidity of 4.734% in comparison with 34.911% for control, and contact angle of 97.8° vs. 80.5° for untreated wood) and UV and fungal attack protection, while maintaining the color and aspect of specimens, was sustained. L.ZnO are well dispersed into the polymer matrix, ensuring a smooth and less porous wood surface. According to the results, the obtained wood coating using both a biodegradable polymeric matrix and a waste-based preservative can be applied for protection against weathering degradation factors, with limited water uptake and swelling of the wood, UV shielding, reduced wood discoloration and photo-degradation, effective protection against fungi, and esthetic quality. Full article

Background: The present study focuses on the development and validation of the Self-Perceived Anhedonia Scale for Adults (SPAS-A), a novel instrument designed to assess pleasure deficits across multiple dimensions of anhedonia, including social, physical, cognitive, and emotional facets. The study aimed to establish the psychometric properties of the scale, including its reliability and validity. Materials and methods: All the data were collected from a sample of 600 participants between February 2024 and November 2024 via Google Forms. Results: Factorial analysis, including Exploratory Factor Analysis and Principal Component Analysis, revealed a four-factor structure, accounting for 72.4% of the total variance, which demonstrated a coherent and multidimensional representation of anhedonia. The reliability of the scale was further supported by high Cronbach’s Alpha values for each subscale, with social anhedonia showing an exceptional value of 0.916, followed by emotional (0.905), cognitive (0.900), and physical (0.873) anhedonia. Conclusions: These findings indicate that SPAS-A is a reliable and valid tool for assessing pleasure deficits in adults, providing a comprehensive measure of anhedonia that can be utilized in both clinical and research settings. Future studies could benefit from longitudinal designs and more diverse samples to better understand the temporal and cultural variability of anhedonia. Full article

This article compares two exfoliation options of multilayered silicate, one considering the action of shear stress and temperature during melt compounding and another taking into account the action of the thermo-mechanical pretreatment of multilayered silicate in a plasticizer common to the starch and polyvinyl alcohol (PVOH), the two polymers from the compound. Increasing the action time of the shear stress and temperature during melt compounding proved to be an ineffective method for silicate exfoliation following the high degradability of starch and PVOH under thermo-mechanical conditions and the loss of hydration of the multilayered silicate under thermo-mechanical conditions. The obtained results prove that, by pretreating before embedding into the desired starch-PVOH matrix, it was possible to cancel the electrostatic attractions between the component lamellae of a multilayered silicate. During melt compounding with the two polymers, new attractions between the obtained lamellae and the polar groups of each polymer from the blend were settled, and so, without the usage of a liquid plasticizer, exfoliated intercalated nanocomposites were achieved. The improved properties and the practical importance of the new nanocomposites regards the obtaining of a non-degradable material that has a white color, better elastic properties and thermal stability, and a higher dissipation capacity of deformation energy. Full article

Hospital-acquired pneumonia (HAP) and its subtype, ventilator-associated pneumonia (VAP), remain two significant causes of morbidity and mortality worldwide, despite the better understanding of pathophysiological mechanisms, etiology, risk factors, preventive methods (bundle of care principles) and supportive care. Prior detection of the risk factors combined with a clear clinical judgement based on clinical scores and dosage of different inflammatory biomarkers (procalcitonin, soluble triggering receptor expressed on myelloid cells type 1, C-reactive protein, mid-regional pro-adrenomedullin, mid-regional pro-atrial natriuretic peptide) represent the cornerstones of a well-established management plan by improving patient’s outcome. This review article provides an overview of the newly approved terminology considering nosocomial pneumonia, as well as the risk factors, biomarkers, diagnostic methods and new treatment options that can guide the management of this spectrum of infections. Full article

Multi-component high-entropy (TiCrAl_0.5NbCu)C_xN_y coatings targeting applications requiring medium-to-high friction and wear-resistant surfaces were fabricated through the co-sputtering of elemental targets in an Ar + CH₄ + N₂ reactive atmosphere using a hybrid HiPIMS/DCMS technique. Two sets of samples were fabricated: (a) (TiCrAl_0.5NbCu)C_x high-entropy carbides (HEC) and (b) (TiCrAl_0.5NbCu)C_xN_0.13 high-entropy carbonitrides (HECN), 0 ≤ x ≤ 0.48. The structural, mechanical, tribological, and corrosion resistance properties were thoroughly investigated. The metallic sample exhibits a single BCC structure that changes to FCC via an intermediary amorphous phase through the addition of C or N to the content of the films. The crystallinity of the FCC phases is enhanced and the density of the films decreases down to 5.5 g/cm³ through increasing the carbon fraction up to 48%. The highest hardness of about 16.9 GPa and the lowest wear rate of about 5.5 × 10⁻⁶ mm³/Nm are presented by the samples with the largest carbon content, x = 0.48. We found a very good agreement between the evolution of H/E and H³/E² parameters with carbon content and the tribological behavior of the coatings. The best corrosion resistance was presented by the low-carbon carbonitride samples, showing a charge transfer resistivity of about 3 × 10⁸ Ω∙cm, which is more than three times larger than that of the metallic HEA. The best tribological characteristics for envisioned application were presented by (TiCrAl_0.5NbCu)C_0.3N_0.13, showing a coefficient of friction of 0.43 and a wear rate of about 7.7 × 10⁻⁶ mm³/Nm. Full article

The structure–property relationship of dielectric elastomers, as well as the methods of improving the control of this relationship, has been widely studied over the last few years, including in some of our previous works. In this paper, we study the control, improvement, and correlation, for a significant range of temperatures, of the mechanical and dielectric properties of polystyrene-b-(ethylene-co-butylene)-b-styrene (SEBS) and maleic-anhydride-grafted SEBS (SEBS-MA) by using graphite (G) as filler in various concentrations. The aim is to analyze the suitability of these composites for converting electrical energy into mechanical energy or vice versa. The dielectric spectroscopy analysis performed in the frequency range of 10 to 1 MHz and at temperatures between 27 and 77 °C emphasized an exponential increase in real permittivity with G concentration, a low level of dielectric losses (≈10⁻³), as well as the stability of dielectric losses with temperature for high G content. These results correlate well with the increase in mechanical stiffness with an increase in G content for both SEBS/G and SEBS-MA/G composites. The activation energies for the dielectric relaxation processes detected in SEBS/G and SEBS-MA/G composites were also determined and discussed in connection with the mechanical, thermal, and structural properties resulting from thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses. Full article

Innovative composites based on polypropylene waste impurified cu HDPE (PPW) combined with two thermoplastic block-copolymers, namely styrene-butadiene-styrene (SBSBC) and styrene-isoprene-styrene (SISBC) block-copolymers, and up to 10 wt% nano-clay, were obtained by melt blending. SBSBC and SISBC with almost the same content of polystyrene (30 wt%) were synthesized by anionic sequential polymerization and used as compatibilizers for PPW. Optical microscopy evaluation of the PPW composites showed that the n-clay was encapsulated into the elastomer. Addition of n-clay, together with SBSBC or SISBC, increased the interphase surface of the components in the PPW composites and enhanced the superficial area/volume ratio, which led to a recycled material with improved performance. The data resulting from differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), mechanical evaluation, and dynamic mechanical analysis (DMA) revealed that PPW reinforcement with n-clay and styrene-diene block-copolymers allows the obtaining of composites with favorable mechanical and thermal properties, and excellent impact strength for potential engineering applications. Full article

Objective: The aim of this study is to propose a standardized management of care for patients diagnosed with cesarean scar pregnancy (CSP). There are two types of CSP: Type 1 (on the scar) vs. type 2 (in the niche). To date there is no international standard to predict the extent of invasion or the optimal management of CSP. Materials and methods: We used intramuscular methotrexate injection followed by uterine artery embolization combined with suction evacuation as a conservative approach for the treatment of seven patients diagnosed with CSP. Our inclusion criteria, to be satisfied simultaneously, were established as follows: (1) patients with CSP; (2) early gestational age ≤ 9 weeks, and (3) written consent of the proposed treatment of the patient. Results: This course of treatment produced a positive outcome in all cases. We did not have any complications (e.g., emergency hysterectomy, perforation of the uterine cavity, severe hemorrhage, or endometritis) during the procedures or in the follow-up. The most important predictors of successful management are early diagnosis of CSP and orientation of the invasive trophoblast opposite to the scar. Conclusions: The main finding from this series of cases is that associating systemic methotrexate and uterine artery embolization provides efficient and low-risk management of CSP. This treatment regime is adequate for both types of CSPs. We consider that early localization diagnosis of pregnancy following a cesarean delivery is mandatory for CSP morbidity prevention. Full article

In this study, we propose a palladium-functionalized CNT composite working as a sensitive material to evaluate the deuterium concentration in aqueous samples. The sensitive material was prepared by the deposition of Pd nanoparticles onto MWCNT–OH by the micellization process. A modified electrode was prepared by drop casting 60 μL of Pd-decorated MWCNT suspension on a clean glassy carbon electrode surface. The sensing behavior was investigated in a series of deuterium-enriched solutions ranging from 25 to 10,000 ppm. We performed cyclic voltammetry and impedance spectroscopy studies on the samples. The process is quasi-reversible with the reduction curve more pronounced than the oxidation curve, which indicates a low tendency to desorption for the hydrogen atoms. Full article

The paper presents the expertise of authenticating a painting by Nicolae Grigorescu through the involvement of multi-analytical techniques, in order to identify and evaluate some archaeometric and chemometric characteristics of the pictorial materials and of the support, used in determining the age. The painting is made with oil colors on pressed cardboard, with preparation based on chalk powder and animal glue. The painting presents two elements as being counterfeit, which have attracted suspicions, namely the signature of the author (presenting a semi-transparent covering veil), and, on the back, a writing of dating, performed by a very controversial art historian. The investigation was carried out by direct analysis with magnification devices, in reflected UV (ultraviolet), VIS (visible), and NIR (near- infrared) light, and by OM, SEM-EDX, and μ-FTIR. The results showed that the painting is authentic and belongs to Nicolae Grigorescu, and the dating established previously by Amelia Pavel through the writing on the back is certain. Full article