Search Results (14,994)

Cables and tendons are crucial elements in bridge engineering but also are vulnerable structural elements because they are usually subjected to fatigue and corrosion problems. Thus, vibration-based non-destructive techniques have been used for external post-tensioning tendon assessment. Regarding continuous monitoring systems, tendon assessment is carried out through the continuous tracking of its natural frequencies and the subsequent estimation of the tension force, as this parameter is essential for the bridge’s overall structural performance, thus providing useful information about bridge safety. However, for long-term monitoring assessment, two main challenges have to be addressed regarding practical applications: (i) double-peak spectra and other spurious factors that affect the frequency estimation, and (ii) temperature dependency, which needs to be carefully treated since frequency/tension variation may be explained by temperature variation, thus masking potential structural anomalies. On this subject, this paper presents the experimental long-term monitoring of several post-tensioning external tendons in a high-speed railway bridge in which a sectorized weighted peak-picking frequency identification procedure is proposed for frequency estimation, alongside a cascade clustering process, which allows meaningful frequency estimates to be selected. Finally, the selected frequency estimates, which show variations from 1 to 2% for all analyzed frequencies, are used for the long-term assessment of the tension force. Full article

Background: Oral candidiasis, predominantly caused by Candida albicans, presents significant challenges in treatment due to increasing antifungal resistance and biofilm formation. Antimicrobial photodynamic therapy (aPDT) using natural photosensitizers like riboflavin and hypericin offers a potential alternative to conventional antifungal therapies. Material and Methods: A systematic review was conducted to evaluate the efficacy of riboflavin- and hypericin-mediated aPDT in reducing Candida infections. The PRISMA framework guided the selection and analysis of 16 eligible studies published between 2014 and 2024. Data on light parameters, photosensitizer concentrations, and outcomes were extracted to assess antifungal effects. Results: Both riboflavin- and hypericin-mediated aPDT demonstrated significant antifungal activity, achieving substantial reductions in Candida biofilm and planktonic cell viability. Riboflavin activated by blue light and hypericin activated by yellow or orange light effectively targeted fluconazole-resistant Candida strains with minimal cytotoxicity to host tissues. However, complete biofilm eradication remained challenging, and variations in protocols highlighted the need for standardization. Conclusions: Riboflavin- and hypericin-mediated aPDT present promising, biocompatible alternatives for managing antifungal resistance in Candida infections. Further clinical trials and standardized protocols are essential to optimize outcomes and confirm efficacy in broader clinical settings. Full article

The water channel AQP3 is an aquaglyceroporin expressed in villus epithelial cells, and it plays a role in water transport across human colonic surface cells. Beyond water, AQP3 can mediate glycerol and H₂O₂ transport. Abnormal expression and function of AQP3 have been found in various diseases often characterized by altered cell growth and proliferation. Here, the beneficial effects of MOMAST^® have been evaluated. MOMAST^® is an antioxidant-patented natural phenolic complex obtained from olive wastewater (OWW) of the Coratina cultivar. Treatment of human colon HCT8 cells with MOMAST^® reduced cell viability. Confocal studies and Western Blotting analysis demonstrated that treatment with MOMAST^® significantly decreased the staining and the expression of AQP3. Importantly, functional studies revealed that the reduction of AQP3 abundance correlates with a significant decrease in glycerol and H₂O₂ uptake. Indeed, the H₂O₂ transport was partially but significantly reduced in the presence of MOMAST^® or DFP00173, a selective inhibitor of AQP3. In addition, the MOMAST^®-induced AQP3 decrease was associated with reduced epithelial-mesenchymal transition (EMT)-related proteins such as vimentin and β-catenin. Together, these findings propose MOMAST^® as a potential adjuvant in colon diseases associated with abnormal cell growth by targeting AQP3. Full article

This study focused on determining the content of bioactive compounds in selected fruits of wild shrubs. The plants selected for the study were from the Rosaceae and Adoxaceae families. Particular attention should be paid to the fruits of plants commonly growing in Poland (temperate climate), such as Crataegus monogyna, Sorbus aucuparia, Viburnum opulus, and Sambucus nigra. The study aimed to deepen the knowledge of the content of selected secondary metabolites, such as phenolic acids, flavonoids, flavonoid glycosides, and their antioxidant properties, as well as natural dyes. During this study, chromatographic and spectrophotometric methods were used to determine the quantitative profile of the above-mentioned secondary metabolites of wild plant fruits. The quantitative profile of 16 phenolic acids, 9 flavonoids, 5 organic acids, 13 flavonoid glycosides, and 3 natural dyes was determined. Based on the studies, it was noted that the qualitative and quantitative profile of the bioactive compounds differs not only depending on the species but also on the location where the plant grows. A statistical analysis showed significant differences (p < 0.05) in the content of phenols and flavonoids in fruits collected from different locations. Interestingly, differences were also observed within the species, probably depending on the geographical location and composition of the soil in which the plants were grown. Full article

The abiotic stresses to which plants are exposed, especially in times of climate change, can result in the disruption of natural plant physiological processes. Sudden atmospheric phenomena may increase the risk of failure in protecting rare and extinction-threatened plant species by translocation. This study aimed to determine the effect of extreme ambient temperatures on the condition and physiological response of Salix lapponum plantlets used for their reintroduction into the natural habitat. Salix lapponum plants obtained by micropropagation methods at different stages of growth under laboratory conditions were subjected to a biological experiment. Plants were exposed for 12 h to temperature extremes (0 °C and 30 °C), after which the values of selected markers of the biochemical response were determined, such as photosynthetic pigments and anthocyanin content, guaiacol peroxidase and catalase activity, the presence of ROS and the RWC value. The study showed that plants at early growth stages were sensitive to low-temperature stress. In contrast, older ones showed a stronger response to high temperature, marked by an increased anthocyanin content and guaiacol peroxidase activity. It was also found that a short exposure to temperature extremes did not change the photosynthetic pigment content or catalase activity. The results of the study may be an important indication for the optimization of plant acclimatization methods in the process of their active protection by species translocation. Full article

Ash dieback is a major issue affecting European ash populations, including narrow-leaved ash (Fraxinus angustifolia Vahl). An important factor contributing to the decline of narrow-leaved ash is the fungal disease caused by Hymenoscyphus fraxineus. However, the mortality of trees also depends on stand structure that may influence the disease dynamics. In 2020, we analysed the stand structure of middle-aged, extensively managed, narrow-leaved ash stands growing on Humogley soil (Cariceto remotae-Fraxinetum angustifoliae, Jov., et Tom. 1979). This permanent sample plot is located in Posavina (Serbia), where we observed reduced tree vitality and mortality. The stand originates from natural regeneration after a succession of marsh habitats. At ages 20–25 years (1996) and 30–35 years (2006), selective thinning was carried out. Until the age of 45–50 years (2020), the stand was left unthinned, and the presence of ash dieback fungus was recorded in Serbia. In 2020, we measured the diameter at breast height (DBH) of each tree on the plot and assessed their crown class and degree of isolation. These parameters were evaluated in relation to the crown defoliation of the trees. The results indicate that reduced vitality and mortality of trees manifest in conditions of strongly expressed intraspecific competition in the stand, particularly during the stem exclusion stage. Healthy trees were observed primarily within the predominant/dominant crown class and exhibited the highest mean DBH. Trees classified as dead or dying (81%–100% defoliation) had a lower mean DBH compared to both healthy trees (<25% defoliation) and significantly defoliated trees (26%–80%). This was observed at both the stand level and in predominant/dominant trees, suggesting that tree mortality is primarily linked to their poor growth. Full article

The economic decline of some rural areas is leading to the development of strategies to enhance the value of local economies. This is particularly important in protected natural spaces, where the aim is to encourage the provision of ecosystem services and strengthen commitment to sustainable development and economic growth. One of the rural development strategies with a growing interest in promoting the sustainability of rural areas in protected natural spaces is the use of territorial brands. The objective of this work is to analyse the social demand for territorial-branded products in protected natural spaces. The territorial brand of Sierra Espuña Regional Park (southeastern Spain) was selected as a pragmatic case, with the aim of promoting the production and consumption of sustainable local products. To this end, a contingent valuation survey of consumers was carried out to study the demand for honey, one of the most characteristic products of this territorial brand. The results demonstrate the high social demand for honey under the Sierra Espuña Territorial Brand, with an average surcharge of almost thirty percent compared to the conventional product, and a positive influence of the perception of supporting ecosystem services on this social demand. These results provide an empirical basis for the integration and promotion of production and marketing strategies with territorial brands, in the interests of rural development from and for the territory. Full article

The prevalence of coniferous trees in the forest landscapes of northeastern Siberia is conditioned by their high frost resistance. The Kajander larch (Larix cajanderi Mayr), which can survive under natural conditions (down to −60 °C) in the cryolithozone of Yakutia, is the dominant forest-forming species. We hypothesise that our study using HPTLC–UV/Vis/FLD, TLC–GC/FID, and GC–MS methods of seasonal features of the lipid profile of Kajander larch tissues will bring us closer to understanding the mechanisms of participation of lipid components in the adaptation of this valuable tree species to the cold climate of the cryolithozone. Rare delta5-unsaturated polymethylene-interrupted fatty acids (∆5-UPIFA) were identified in the fatty acids (FAs) of L. cajanderi shoots, including 18:2(Δ5.9) (taxoleic), 18:3(Δ5.9.12) (pinolenic), and 18:4(Δ5.9.12.15) (coniferonic). It was found that the content of ∆5-UPIFA in L. cajanderi shoots markedly increased (1.5-fold, representing up to 23.9% of sum FAs) during the autumnal transition of trees to dormancy. It was observed that the ranges of low temperatures experienced during the prolonged winter period primarily determined the structural diversity of membrane lipids and their constituent FAs during the cold adaptation of L. cajanderi. The results obtained can be used for the selection of molecular markers of cold tolerance in woody plants, including fruit trees. Full article

Background/Objectives: The rapid evolution of bacterial resistance and the high cost of drug development have attributed greatly to the dearth in drug design. Computational approaches and natural product exploitation offer potential solutions to accelerate drug discovery. Methods: In this research article, we aimed to identify novel antibacterial hits. For the in silico studies, molecular scaffolds from the in-house chemical library of the Department of Pharmacy of Athens (Pharmalab) and the National Cancer Institute (NCI) were screened and selected for further experimental procedures. Compounds from both libraries that were not previously screened for their antimicrobial properties were tested in vitro against Gram-positive and Gram-negative bacterial strains. The microdilution method was used to determine the minimum inhibitory concentrations (MICs). Results: In silico screening identified twenty promising molecules from the NCI and seven from the Pharmalab databases. The unexplored compounds for their antibacterial activity can be characterized as weak strain-specific antimicrobials. The NSC 610491 and NSC 610493 were active against Staphylococcus aureus (MIC: 25 and 12.5 µg/mL, respectively) and methicillin-resistant S. aureus (MRSA) (MIC: 50 and 12.5 µg/mL, respectively). Six out of seven hydroxytyrosol (HTy) compounds were moderately active (MIC: 25–50 µg/mL) against S. aureus, MRSA and Enterococcus faecalis. For the Gram-negative bacteria, no activity was detected (≥100 µg/mL). Conclusions: The tested scaffolds could be considered as promising candidates for novel antimicrobials with improvements. Further experimentation is required to assess mechanisms of action and evaluate the efficacy and safety. Full article

Alginate is an important natural biopolymer and metal ion-induced gelation is one of its most significant functional properties. Alginate-based hydrogels crosslinked with metal ions are commonly utilized in the food, biomedical, tissue engineering, and environment fields. The process of metal ion-induced alginate gelation has been the subject of thorough research over the last few decades. This review aims to summarize the mechanisms of alginate hydrogels induced by different cations (primarily including Ca²⁺, Ba²⁺, Cu²⁺, Sr²⁺, Fe²⁺/Fe³⁺, and Al³⁺). Metal ion-induced alginate gelation shows different preferences for α-L-guluronic acid (G), β-D-mannuronic acid (M), and GM blocks. Some metal ions can also selectively bind to the carboxyl groups of guluronic acid. The properties and applications of these alginate-based hydrogels are also discussed. The primary objective of this review is to provide useful information for exploring the practical applications of alginate. Full article

Extracts from natural waste like bark or leaves are great sources of phytochemicals, which contain functional groups (hydroxyl, carboxylic, vinyl, allyl) attractive in terms of polymer synthesis. In this study, the synthesis of epoxy with an extract of Scots pine bark as a natural co-hardener was evaluated. Ultraviolet-visible (UV-Vis) spectroscopy was used for the identification of phytochemicals with conjugated dienes and quantification of TPC. Also, the total solid content (TSC) of representative extracts was calculated. The best extract in terms of total phenolic content (TPC) value was selected as a co-hardener and investigated using differential scanning calorimetry (DSC) for thermal effects and attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) for reactions between functional groups. Also, the mechanical properties (flexural modulus, flexural strength, impact strength, Shore D hardness) and density of composition were obtained for extract-based epoxy and compared to reference sample values. Results were discussed in terms of future research and improvement of compositions. Also, potential applications were proposed. Full article

The building sector contributes approximately half of all carbon emissions. The heating stage accounts for the largest proportion of building carbon emissions. The focus on carbon-reduction strategies in rural areas could not be copied from urban buildings due to different heating modes limited by economic factors. The Gannan region in Gansu province was selected to carry out an on-site survey on heating conditions, including the heating modes, the energy used for heating, heating fees, residents’ satisfaction with heating, and the thermal environment of the typical building. The results showed that local rural residents burnt scattered coal for heating using primitive heating stoves with low efficiency, causing low air temperatures and high heating fees. The carbon emissions generated by heating reached 5743.28 kgCO₂e·m⁻². Several strategies for reducing carbon emissions were proposed, considering the economic benefits limited by rural economic development. A parameter of reduced carbon emissions per investment input was proposed to evaluate the carbon-reduction strategies. The results showed that biomass was the most economical way to reduce carbon emissions. Reduced carbon emissions per investment input reached 44.19 kgCO₂e·CNY⁻¹ with energy efficiency of 50%, followed by thermal insulation design of 32.31 kgCO₂e·CNY⁻¹, natural gas furnaces of 26.08 kgCO₂e·CNY⁻¹, and air-source heat pumps of 20.27 kgCO₂e·CNY⁻¹. In addition, carbon emissions generated by biomass were 12.4% and 24% of those caused by coal and natural gas supplying the same energy. Moreover, building insulation should be increased according to economic benefits. The optimum energy efficiency was 55% in Gannan. The results provided a reference for building low-carbon heating in rural areas, which could help achieve the low-carbon goal with low investments. Full article

Rosmarinic acid (RA) is a natural active compound widely found in many plants belonging to the family of Lamiaceae, Boraginaceae, and so on, which has various important bioactivities, including being anti-oxidative, anti-inflammatory, antiviral, etc. Herein, novel hydrophilic magnetic molecularly imprinted polymers (HMMIPs) with a regular core-shell structure were successfully developed using RA as a template molecule, acrylamide (AM) as a functional monomer, N-N ’methylenebisacrylamide (MBA) as a cross-linking agent, and water as the porogen. After a series of characterization and adsorption performance analyses, it was found that HMMIPs are hydrophilic with an adsorption capacity of 8.012 ± 0.54 mg/g, an imprinting factor of 3.64, and a selectivity coefficient of 2.63~2.91. Furthermore, the HMMIPs can be rapidly separated from other components under the influence of external magnetic fields. The HMMIPs were employed for the determination of RA present in the Perilla frutescens and Rosmarinus officinalis aqueous extract with recoveries of 88.2~107.3%. These results indicated that HMMIPs of RA have the benefits of straightforward operation, rapid adsorption, and high selectivity, rendering it an appropriate way for the expedient and selective isolation of RA in an intricate matrix. Full article

ROS (i.e., reactive oxygen species) scavenging is a key function of various Mn-based enzymes, including superoxide dismutases (SODs) and catalases, which are actively linked to oxidative stress-related diseases. In this study, we synthesized and characterized two novel Mn(III)-based synzymes (i.e., synthetic enzymes), designated C1 ([MnL1Cl(H₂O)]Cl·3H₂O) and C2 ([MnL2Cl₂]·2H₂O), which differ in the presence of a bridging aliphatic or aromatic group in the chelator. Using a range of analytical techniques, we found that the aromatic C2 bridge significantly influences the Mn(III) center’s cis-β configuration, unlike C1, which adopts a trans configuration. We then thoroughly evaluated the oxidation-reduction properties of C1 and C2, including their redox potentials (by cyclic voltammetry) and capacity to consume various ROS species (using DPPH, hydroxyl radical, hydrogen peroxide, and superoxide UV–visible spectrophotometric assays). The specific kinetics of the H₂O₂ dismutation process, as measured by a Clark-type electrode and time-resolved ESI-MS, revealed that both synzymes possess catalytic activity. Toxicological experiments using the Galleria mellonella larval model demonstrated the compounds’ innocuous nature towards higher eukaryotic organisms, while cytotoxicity assays confirmed their selective efficacy against lung cancer cells. Additional cytological assays, such as the thiobarbituric acid reactive substances assay and caspase-3 activity and p53 expression analysis, reported that C1 and C2 induce cytotoxicity against cancer cells via apoptosis rather than necrosis and behave very differently towards redox substances and ROS-regulating enzymes in vivo. These findings suggest that the structural differences between C1 and C2 lead to distinct redox properties and biological activities, highlighting the potential of these novel Mn(III)-based synzymes as therapeutic agents for the treatment of oxidative stress-related diseases, particularly lung cancer. Further studies are warranted to elucidate the underlying mechanisms of action and explore their clinical applications. Full article

To sustain agricultural productivity and safeguard global food security, and confront the escalating challenges posed by climate change and water scarcity, it is essential to enhance the growth and productivity of rice under water stress. This study investigated the effects of lanthanum chloride on the chlorophyll fluorescence characteristics and grain yield of rice under different irrigation modes. The rice cultivar H You 518 was selected and sprayed 20, 100, or 200 mg·L⁻¹ lanthanum chloride at the booting and heading stages under deficit irrigation (where no rewatering was applied after the initiation of stress, allowing the water layer to evaporate naturally under high temperatures) or conventional irrigation (with daily rewatering to maintain a consistent water level). The results showed that the application of low concentrations lanthanum chloride promoted the chlorophyll content, whereas high concentrations decreased the chlorophyll content, under deficit irrigation, the effect of lanthanum chloride on the green fluorescence parameters of rice leaves at the booting stage was greater than that at the heading stage, and the booting stage was more sensitive to water deficit. The application of 100 mg·L⁻¹ lanthanum chloride reduced the initial fluorescence (F0) and the non-photochemical quenching coefficient (qN); promoted the activity of leaf photosynthetic system II (PSII); and maximized the photochemical quantum yield (Fv/Fm), photochemical quenching coefficient (qP), and PSII relative electron transfer efficiency (ETR). Under deficit irrigation, this treatment significantly enhanced grain yield by increasing the thousand-grain weight, spikelet filling rate, and number of grains per panicle. These results suggest that spraying 100 mg·L⁻¹ lanthanum chloride at the booting stage under deficit irrigation can effectively increase the chlorophyll content, thereby increasing the light energy conversion efficiency of the PS II reaction center, ultimately resulting in increased spikelet filling rate and grain yields. Full article