Search Results (33)

The negative consequences of climate change—such as heatwaves, storms, and floods—together with emerging threats including war, radiation, and pandemics, are increasingly affecting human health, ecosystems, economic stability, and the overall living environment. Consequently, enhancing preparedness has become a key task in shaping the spatial structure of cities. However, despite the growing negative impact and increasing frequency of climate change consequences, along with the prevailing risk of other threats, Lithuania is still not adequately prepared. The article examines the urban environment of Lithuanian cities and its local climatic assessment, aiming to develop proposals to enhance the sustainability and resilience of this environment in addressing the negative consequences of these threats. Three main climatic regions of the country were selected for the research, represented by cities: Klaipėda, Kaunas, and Vilnius. Urban and local climatic research was carried out in the selected cities to assess their spatial structure and environment and identify for microclimatic research the unified morphostructure types commonly used in the country. Accordingly, to selected morphotypes, correlations of the relationship between development density, building height, and the area of impervious surfaces with air and surface temperatures were carried. The most favourable microclimatic conditions were identified in morphotypes characterised by lower development density, more abundant green spaces, and a more open development pattern. Such characteristics of urban morphostructures, considering additional factors of land use such as land saving and the efficient functioning of the city, form the basis for developing the spatial structure of sustainable urban residential areas. Full article

The design and development of scaffolds play a crucial role in tissue engineering. In this regard, the study aims to establish the influence of porosity on the morpho-structural, physical–chemical, and biochemical characteristics of the polylactic acid (PLA) and/or polycaprolactone (PCL) scaffolds, in order to be considered candidates for tissue reconstruction. The results indicated that binary PLA-PCL and PCL matrices are more suitable than PLA, due to their higher crystallization degree, this contributing to the superior mechanical properties and lower network defects. The preponderance of molecular interactions decreases with porosity. Porosity induced a decrease in the degree of crystallization of PLA-PCL and an increase in water, glucose and blood components uptake by 188, 178, and 28%, respectively. The PLA-PCL scaffold was found to be more stable to lipase action than neat PLA as a result of the reduced enzyme access due to the higher crystallinity and thermodynamic stability of the hydrocarbon linear chain in PCL, which is higher than that of the side methyl group in PLA. Lactobacillus growth increases with porosity and was more pronounced on the PLA-PCL matrix. All these results show that varying the porosity and composition of the polymer mixture leads to valuable materials with nutrient absorption capacity and biodegradability superior to neat PLA or PCL materials. Full article

Global climate change has intensified the frequency, intensity, and spatial heterogeneity of drought events, posing severe threats to the stability of terrestrial ecosystems. Plant drought resilience, which encompasses a plant’s capacity for drought resistance, post-stress recovery, and long-term adaptation and transformation to sustain ecosystem functionality, has emerged as a central focus in botanical and ecological research. This review synthesizes the conceptual evolution of plant drought resilience, from early emphasis on resistance and recovery to the current multi-dimensional framework integrating adaptation and transformation, and synthesizes advances in understanding multi-scale drought resilience in terrestrial plants—spanning molecular, physiological, individual, community, and ecosystem levels. Key mechanisms include molecular/physiological adaptations (osmotic adjustment, antioxidant defense, hydraulic regulation, carbon–water reallocation via gene networks and aquaporins), morpho-anatomical traits (root architectural plasticity, leaf structural modifications, and hydraulic vulnerability segmentation), community/ecosystem drivers (biodiversity effects, microbial symbioses, and soil–plant–feedback dynamics). We critically evaluate quantitative metrics and expose critical gaps, including neglect of stress legacy effects, oversimplified spatiotemporal heterogeneity, and limited integration of concurrent stressors. Future research should prioritize multi-scale and multi-dimensional integrated analysis, long-term multi-scenario simulations with field validation, and harnessing plant–microbe interactions to enhance drought resilience, providing a theoretical basis for ecosystem sustainability and agricultural production under climate change. Full article

One of the main challenges in hydroxyapatite research is to develop cost-effective synthesis methods that consistently produce materials closely resembling natural bone, while maintaining high biocompatibility, phase purity, and mechanical stability for biomedical applications. Traditional synthetic techniques frequently fail to provide desirable mechanical characteristics and antibacterial activity, necessitating the development of novel strategies based on natural precursors and selective ion doping. The present study aims to explore the possibility of synthesizing hydroxyapatite through the co-precipitation method, followed by a microwave-assisted hydrothermal maturation process. The main CaO sources selected for this study are eggshells and mussel shells. Cu²⁺ and Sr²⁺ ions were added into the hydroxyapatite structure at concentrations of 1% and 5% to investigate their potential for biomedical applications. Furthermore, the morpho-structural and biological properties have been investigated. Results demonstrated the success of hydroxyapatite synthesis and ion incorporation into its chemical structure. Moreover, HAp samples exhibited significant antimicrobial properties, especially the samples doped with 5% Cu and Sr. Additionally, all samples presented good biological activity on MC3T3-E1 osteoblast cells, demonstrating good cellular viability of all samples. Therefore, by correlating the results, it could be concluded that the undoped and doped hydroxyapatite samples are suitable biomaterials to be further applied in orthopedic applications. Full article

The friction surfacing (FS) process has emerged over the past few years as a method for joining both similar and dissimilar materials, for volume damage repair of defective components, and for corrosion protection. The possibility to produce a metallic coating by FS, without melting the material, classifies this technique as distinct from other standard methods. This unconventional deposition method is based on the severe plastic deformation that appears on a rotating metallic rod (consumable material) pressed against the substrate under an axial load. The present study aims to investigate the tribological properties and corrosion resistance provided by the aluminum-based FS coatings deposited onto a structural S235 steel substrate and further modified by plasma electrolytic oxidation (PEO). During the PEO treatment, the formation of a ceramic film is enabled, while the hardness, chemical stability, corrosion, and wear resistance of the modified surfaces are considerably increased. The morpho-structural characteristics and chemical composition of the PEO-modified FS coatings are further investigated using scanning electron microscopy combined with energy dispersive spectroscopy analysis and X-ray diffraction. Dry sliding wear testing of the PEO-modified aluminum-based coatings was carried out using a ball-on-disc configuration, while the corrosion resistance was electrochemically evaluated in a 3.5 wt.% NaCl solution. The corrosion rates of the aluminum-based coatings decreased significantly when the PEO treatment was applied, while the wear rate was substantially reduced compared to the untreated aluminum-based coating and steel substrate, respectively. Full article

Background/Objectives: Zingiber officinale Roscoe (Zingiberaceae) is widely recognized for its diverse biological activities; however, the stability and bioavailability of its bioactive compounds remain significant challenges. This study aimed to investigate an innovative approach to enhance the stability and efficacy of Z. officinale phytoconstituents through advanced encapsulation techniques. Methods: Two novel carrier systems were developed: (i) direct micro-spray encapsulation of Z. officinale in maltodextrin (MZO) and (ii) a two-step process involving the creation of a kaolinite-based phytocarrier system (ZO–kaolinite), followed by micro-spray encapsulation in maltodextrin to form the MZO–kaolinite system. Results: Comprehensive chemical profiling using GC–MS and ESI–QTOF–MS identified 105 phytochemicals, including terpenoids, gingerols, shogaols, flavonoids, and phenolic acids. Morphostructural analyses (XRD, FTIR, Raman, SEM) confirmed the successful development of the newly engineered kaolinite carrier systems (ZO–kaolinite and MZO–kaolinite systems). Both the ZO–kaolinite and MZO–kaolinite systems exhibited superior antioxidant activity, potent antimicrobial efficacy against major bacterial pathogens (Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli), and enhanced cytotoxicity against MCF-7, HCT-116, and HeLa cancer cell lines. Conclusions: This study underscores the synergistic action of kaolinite and maltodextrin in developing multifunctional therapeutic systems, emphasizing the importance of phytoconstituent stabilization and nanotechnology in addressing antimicrobial resistance and advancing innovative medical applications. Full article

A spin-coating technique was used to produce new thin films of fluoride-doped hydroxyapatite (HApF) and fluoride-doped hydroxyapatite in a dextran matrix (HApF-Dx) with the potential to be used as nanocoatings for various biomedical implants. The stability of the suspensions used in obtaining the thin films was confirmed by ultrasonic measurements with double-distilled water as a reference. The HApF and HApF-Dx thin films obtained by spin-coating showed diffraction patterns corresponding to hexagonal hydroxyapatite. The X-ray photoelectron spectroscopy studies confirmed the partial substitution of hydroxyl groups (-OH) by fluoride ions. The FTIR studies were conducted in order to highlight the presence of the functional group specific for the HAp in the samples and the influence of the dextran addition on the vibrational characteristics. The surface morphologies of the HApF and HApF-Dx thin films were explored using scanning electron microscopy (SEM), atomic force microscopy (AFM), and metallographic microscopy (MM). The surfaces of the HApF and HApF-Dx thin films were found to be smooth, homogenous, and nanostructured. The biocompatibility assays on HGF-1 cells confirmed that both coatings exhibited good cell viability for all the tested time intervals (24 and 48 h). The findings highlighted the potential of HApF and HApF-Dx coatings for biomedical applications. Additional information about the HGF-1 adherence and development on the surface of the HApF and HApF-Dx coatings was obtained using metallographic microscopy, scanning electron microscopy, and atomic force microscopy techniques. This research demonstrates that the spin-coating method can be successfully used to fabricate HApF and HApF-Dx nanocoatings for potential biomedical applications. Full article

Enhancing the photocatalytic efficiency of oxide materials under Vis light remains a significant challenge within the scientific community. Natural zeolite–metal oxide composites exhibit enhanced properties, especially due to the zeolite’s large active surface area, which facilitates the incorporation of metal oxide nanoparticles into its structure, thereby significantly increasing photocatalytic efficiency. The present study presents the synthesis of Na-zeolite-decorated black-TiO₂ by the impregnation method, in order to improve the structural characteristics to absorb into visible light. The experimental protocol involves two main steps: first, the synthesis of black-TiO₂ and white-TiO₂ nanocrystals using the sol-gel method, and second, the preparation of hybrid materials, consisting of Na-zeolite decorated with black-TiO₂ and white-TiO₂, through impregnation followed by thermal treatment. The morpho-structural and optical properties of the as-synthesized materials were investigated using XRD, SEM/EDX, FTIR, and DRUV-VIS analysis. The characterization results indicated that natural zeolite has a good thermal stabilization, the lamellar texture of natural zeolite and spherical form of anatase-TiO₂ materials being highlighted by SEM. In the case of Na-zeolite-decorated black-TiO₂, the adsorption edge is slightly shifted to the visible range, while Na-zeolite-decorated white-TiO₂ absorbs only in the ultraviolet region. The above results showed that these hybrid materials are adequate for application in photocatalytic processes. Full article

Despite the huge progress achieved in the optimization of perovskite solar cell (PSC) performance, stability remains a limiting factor for technological commercialization. Here, a study on the photovoltaic, structural and morphological stability of semi-transparent formamidinium lead bromide-based PSCs is presented. This work focuses on the positive role of 2D nanoscale layer passivation, induced by perovskite surface treatment with a mixture of iso-Pentylammonium chloride (ISO) and neo-Pentylammonium chloride (NEO). In situ X-ray diffraction (XRD) is applied in combination with atomic force microscopy (AFM), and the results are correlated to the devices’ photovoltaic performances. The superior power conversion efficiency and overall stability of the ISO-NEO system is evidenced, as compared to the un-passivated device, under illumination in air. Furthermore, the role of the ISO-NEO treatments in increasing the morpho-structural stability is clarified as follows: a bulk effect resulting in a protective role against the loss in crystallinity of the perovskite 3D phase (observed only for the un-passivated device) and an interface effect, being the observed 2D phase crystallinity loss spatially localized at the interface with the 3D phase where a higher concentration of defects is expected. Importantly, the complete stability of the device is achieved with the passivated ISO-NEO-encapsulated device, allowing us to exclude the intrinsic degradation effects. Full article

The laser pyrolysis technique was used in the synthesis of magnetic iron oxide nanopowders in the presence of ethanol vapors as a sensitizer. This technique uses the energy from a continuous-wave CO₂ laser operating at a 9.25 μm wavelength, which is transferred to the reactive precursors via the excited ethanol molecules, inducing a rapid heating of the argon-entrained Fe(CO)₅ vapors in the presence of oxygen. For a parametric study, different samples were prepared by changing the percentages of sensitizer in the reactive mixture. Moreover, the raw samples were thermally treated at different temperatures and their morpho-structural and magnetic properties were investigated. The results indicated a high degree of crystallinity (mean ordered dimension) and enhanced magnetic properties when high percentages of ethanol vapors were employed. On the contrary, at low ethanol concentrations, due to a decrease in the reaction temperature, nanoparticles with a very low size were synthesized. The raw particles have a dimension in the range of 2.5 to 10 nm (XRD and TEM). Most of them exhibited superparamagnetic behavior at room temperature, with saturation magnetization values up to 60 emu/g. The crystalline phase detected in samples is mainly maghemite, with a decreased carbon presence (up to 8 at%). In addition to the expected Fe-OH on the particles surfaces, C (and O) bearing functional groups such as C-OH or C=O that act as a supplementary hydrophilic agent in water-based suspension were detected. Using the as-synthesized and thermally treated nanopowders, water suspensions without or with hydrophilic agents (CMCNa, L-Dopa, chitosan) were prepared by means of a horn ultrasonic homogenizer at 0.5 mg/mL concentrations. DLS analyzes revealed that some powder suspensions maintained stable agglomerates over time, with a mean size of 100 nm, pH values between 4.8 and 5.3, and zeta-potential values exceeding 40 mV. All tested agents greatly improved the stability of 250–450 °C thermally treated NPs, with L-Dopa and Chitosan inducing smaller hydrodynamic sizes. Full article

In Romanian ethnopharmacology, Eupatorium cannabinum species is known for its remarkable biological activity. We present an advanced approach to encapsulation using maltodextrin matrices to enhance the stability and efficacy of phytoconstituents and nanoparticles. Two distinct carrier systems were developed: (i) a direct micro-spray encapsulation of E. cannabinum in maltodextrin to produce a maltodextrin-encapsulated carrier (MEC), and (ii) a two-step process involving the preparation of a new phytocarrier system based on gold nanoparticles (EC-AuNPs), followed by micro-spray encapsulation in maltodextrin to create the maltodextrin-encapsulated AuNPs system (MEC-AuNPs system). Comprehensive chemical profiling using GC–MS and ESI–QTOF–MS revealed 80 bioactive molecules, including terpenoids, alkaloids, flavonoids, and phytoecdysteroids. Morpho-structural (XRD, FTIR, Raman spectroscopy, SEM) and thermal analyses confirmed the successful integration of NPs within the matrices. EC-AuNPs and MEC-AuNPs exhibited superior antioxidant activity, significant antimicrobial efficacy against major bacterial pathogens (S. aureus, B. subtilis, B. cereus, P. aeruginosa, S. typhi, and E. coli), and enhanced cytotoxicity against MCF-7 and HT-29 cancer cell lines. This study highlights the potential of combining E. cannabinum with AuNPs and maltodextrin encapsulation to develop multifunctional therapeutic systems. The findings underscore the importance of phytoconstituent stabilization and nanotechnology in addressing global antimicrobial resistance and advancing innovative medical applications. Full article

Cold acclimation before winter has been shown to enhance the cold tolerance of evergreen conifers, including Pinus massoniana Lamb., a characteristic heteroblastic foliage tree in the conifer. In the initial growing season of P. massoniana, both primary needle seedlings (PNSs) and secondary needle seedlings (SNSs) are generated. While previous research has highlighted differences in the morphological structure and photosynthetic physiological functions of primary and secondary needles, their response to cold acclimation remains poorly understood. This study aimed to investigate the changes in morpho-anatomical structure, starch grain accumulation, and lignin deposition in the roots, stems, and leaves of PNSs and SNSs during cold acclimation using solid potassium iodide and hydrochloric acid phloroglucinol double-staining techniques. The results revealed that, during cold acclimation, the leaves and stems of PNSs exhibited sensitivity to low-temperature stress, resulting in noticeable shrinkage and fracture of mesophyll and cortical parenchyma cells. Furthermore, the early stages of cold acclimation promoted the accumulation of starch grains and lignin in the seedling tissues. In contrast to PNSs, the leaves and stems of SNSs exhibited a shorter cold acclimation period, attributed to the hydrolysis of starch grains in the epidermal cell walls and the transformation of xylem lignin, which supports cell structure stability and enhances cold resistance. In conclusion, these findings suggest that SNSs displayed a superior cold resistance potential compared to PNSs following cold acclimation, providing a significant theoretical basis for the further screening of cold-tolerant germplasm resources of P. massoniana and the analysis of cold resistance traits in heteroblastic foliage. Full article

Globally, huge amounts of cotton and sunflower stalks are generated annually. These wastes are being underutilized since they are mostly burned in the fields. So, in this work, we proposed a three-step method consisting of acid pre-treatment, alkaline hydrolysis, and bleaching for the extraction of cellulose pulps. These pulps were characterized to assess their morpho-structural and thermal properties. The design of experiments and response surface methodology were used for the optimization of the acid pre-treatment in order to achieve maximum removal of non-cellulosic compounds and obtain pulps enriched in cellulose. For cotton stalks, optimal conditions were identified as a reaction time of 190 min, a reaction temperature of 96.2 °C, and an acid (nitric acid) concentration of 6.3%. For sunflower stalks, the optimized time, temperature, and acid concentration were 130 min, 73.8 °C, and 8.7%, respectively. The pulps obtained after bleaching contained more than 90% cellulose. However, special care must be taken during the process, especially in the acid pre-treatment, as it causes the solubilization of a great amount of material. The characterization revealed that the extraction process led to cellulose pulps with around 69–70% crystallinity and thermal stability in the range of 340–350 °C, ready to be used for their conversion into derivatives for industrial applications. Full article

Novel nanotechnology based on herbal products aspires to be a high-performing therapeutic platform. This study reports the development of an original engineering carrier system that jointly combines the pharmacological action of Chelidonium majus and AuNPs, with unique properties that ensure that the limitations imposed by low stability, toxicity, absorption, and targeted and prolonged release can be overcome. The metabolite profile of Romanian wild-grown Chelidonium majus contains a total of seventy-four phytochemicals belonging to eight secondary metabolite categories, including alkaloids, amino acids, phenolic acids, flavonoids, carotenoids, fatty acids, sterols, and miscellaneous others. In this study, various techniques (XRD, FTIR, SEM, DLS, and TG/DTG) were employed to investigate his new carrier system’s morpho-structural and thermal properties. In vitro assays were conducted to evaluate the antioxidant potential and release profile. The results indicate 99.9% and 94.4% dissolution at different pH values for the CG-AuNPs carrier system and 93.5% and 85.26% for greater celandine at pH 4 and pH 7, respectively. Additionally, three in vitro antioxidant assays indicated an increase in antioxidant potential (flavonoid content 3.8%; FRAP assay 24.6%; and DPPH 24.4%) of the CG-AuNPs carrier system compared to the herb sample. The collective results reflect the system’s promising perspective as a new efficient antimicrobial and anti-inflammatory candidate with versatile applications, ranging from target delivery systems, oral inflammation (periodontitis), and anti-age cosmetics to extending the shelf lives of products in the food industry. Full article

The cutting-edge field of nanomedicine combines the power of medicinal plants with nanotechnology to create advanced scaffolds that boast improved bioavailability, biodistribution, and controlled release. In an innovative approach to performant herb nanoproducts, Sideritis scardica Griseb and clinoptilolite were used to benefit from the combined action of both components and enhance the phytochemical’s bioavailability, controlled intake, and targeted release. A range of analytical methods, such as SEM-EDX, FT-IR, DLS, and XDR, was employed to examine the morpho-structural features of the nanoproducts. Additionally, thermal stability, antioxidant screening, and in vitro release were investigated. Chemical screening of Sideritis scardica Griseb revealed that it contains a total of ninety-one phytoconstituents from ten chemical categories, including terpenoids, flavonoids, amino acids, phenylethanoid glycosides, phenolic acids, fatty acids, iridoids, sterols, nucleosides, and miscellaneous. The study findings suggest the potential applications as a promising aspirant in neurodegenerative strategy. Full article