Search Results (89)

pH is a critical parameter requiring precise monitoring across scientific, industrial, and biological domains. Fluorescent pH probes offer a powerful alternative to traditional methods (e.g., electrodes, indicators), overcoming limitations in miniaturization, long-term stability, and electromagnetic interference. By utilizing photophysical mechanisms—including intramolecular charge transfer (ICT), photoinduced electron transfer (PET), and fluorescence resonance energy transfer (FRET)—these probes enable high-sensitivity, reusable, and biocompatible sensing. This review systematically details recent advances, categorizing probes by operational pH range: strongly acidic (0–3), weakly acidic (3–7), strongly alkaline (>12), weakly alkaline (7–11), near-neutral (6–8), and wide-dynamic range. Innovations such as ratiometric detection, organelle-specific targeting (lysosomes, mitochondria), smartphone colorimetry, and dual-analyte response (e.g., pH + Al³⁺/CN⁻) are highlighted. Applications span real-time cellular imaging (HeLa cells, zebrafish, mice), food quality assessment, environmental monitoring, and industrial diagnostics (e.g., concrete pH). Persistent challenges include extreme-pH sensing (notably alkalinity), photobleaching, dye leakage, and environmental resilience. Future research should prioritize broadening functional pH ranges, enhancing probe stability, and developing wide-range sensing strategies to advance deployment in commercial and industrial online monitoring platforms. Full article

Piezo1 is a mechanosensitive non-selective cation channel. Genetic alterations of the channel result in a hematologic phenotype named Hereditary Xerocytosis. With Yoda1 and, more recently, Yoda2, compounds to increase the activity of Piezo1 have become available. However, their concrete effect depends on the nano environment of the channel and hence on the cell type. Here we compare the potency of Yoda1 and Yoda2 in red blood cells (RBCs). We investigate the effect of the compounds on direct channel activity using automated patch clamp, as well as the secondary effects of channel activation on signalling molecules and cellular response. In terms of signalling, we investigate the temporal response of the second messenger Ca²⁺, and in terms of cellular response, the activity of the Gárdos channel. The opening of the Gárdos channel leads to a hyperpolarisation of the RBCs, which is measured by the Macey–Bennekou–Egée (MBE) method. Although the interpretation of the data is not straightforward, we discuss the results in a physiological context and provide recommendations for the use of Yoda1 and Yoda2 to investigate RBCs. Full article

Life expectancy around the world has increased significantly in recent decades, but chronic diseases and an aging population have also grown considerably. Accordingly, the world’s research attention has increasingly focused on the study of possible dietary patterns that can promote healthy aging and the well-being of individuals. Method: This review exposes three different dietary patterns that share various foods which, individually, could promote healthy aging. Following an intensive literature search, the choice of dietary patterns included the Mediterranean diet, the plant-based diet, and the Nordic diet. Results: The foods selected in this review, with the aim of promoting healthy aging and individual well-being, are those shared by the three diet patterns (Mediterranean diet, plant-based diet, and Nordic diet). In particular, the possible positive effects of these foods were investigated through the study of various pathways involved in the aging process, as well as oxidative stress, which underlies aging itself. Conclusions: Although the results are very encouraging, as they show a beneficial effect of the aliments examined, to date, many hallmarks of aging, as well as its characteristic pathways, are not concretely investigated, especially considering the foods examined. For example, deregulated nutrient sensing, stem cell exhaustion, and cellular senescence are additional important hallmarks that are not currently examined. Full article

The importance of lipid molecules present at the level of cell membranes is already well known. They can act as secondary messengers, participating in signal transduction processes that regulate various organ functions; furthermore, their nature significantly influences cellular properties and functions. Recent studies have seen how the lipid composition of cell membranes is connected to the animal lifespan and the onset of several pathological conditions. While numerous studies have been conducted aimed at characterizing the membrane lipidomic profile in the human field, in the animal field, especially in pets, the number of studies is very limited. In recent years, preliminary analyses have been conducted to provide initial information on the composition of membrane fatty acids in healthy pets and those with chronic enteropathy. The results of these studies are very interesting as they highlight differences in fatty acid composition between the two groups of animals. Obviously, a greater number of works is needed to obtain more reliable results and to analyze how the membrane lipid composition can vary in different breeds and sizes of dogs and cats in an attempt to understand the mechanisms underlying it. The present review is divided into three main parts: the first one examines the close influence of fatty acids on membrane properties/functions, the second one presents the main lipidomic analyses conducted so far on companion animals, and the third and final part summarizes the latest works on the link between membrane lipid profiles and animal lifespans, also focusing on dietary and non-dietary strategies able to influence it. Membrane lipidomics allows us to obtain a concrete overview of an animal’s metabolism and nutrition; furthermore, lipid alterations could be used as biomarkers for the early diagnosis of pathologies. This represents an innovative tool in the veterinary field to monitor the metabolic/health status of animals. Full article

According to EU directives, it is necessary to improve the energy consumption of buildings. Therefore, the aim of this study was to improve the physical properties of foamed concrete produced using plaster mortar. For this purpose, polystyrene granulate with a bulk density of 13 kg/m³ in amounts of 4, 7, and 10 g per 1 kg of plaster mortar and a foaming agent in amounts of 2, 4, and 6% of the cement mass were used. The density, thermal conductivity coefficient, compressive and flexural strengths, and water absorption coefficient due to capillary action were determined. Based on the obtained results, it can be concluded that the density, thermal conductivity coefficient, and water absorption coefficient due to capillary action decreased with an increase in the content of polystyrene granulate addition, which is a beneficial outcome. However, at the same time, a reduction in mechanical properties was demonstrated. With an increase in the content of the foaming agent, the density and thermal and mechanical properties decreased. The water absorption coefficient due to capillary action increased with the foaming agent content for samples with the addition of polystyrene granulate. However, the coefficient for all the tested samples was lower than that for the base sample. Full article

The elastic modulus is one of the fundamental parameters controlling the mechanical behaviour of concrete. In this study, the Movable Cellular Automata (MCA) method is applied to predict the Young’s modulus of concrete based on the properties of its components. Each automaton represents one component: cement paste, fine aggregate, or coarse aggregate. A parametric sensitivity analysis was performed using Grey System Theory (GST) on hypothetical concrete modeled with the MCA method. The analysis showed that the coarse aggregate type, coarse aggregate-to-total aggregate ratio, and water-to-cement ratio have the greatest impact on the Young’s modulus. To test the effectiveness of the MCA method in modelling concrete, results of numerical simulations were compared with experimental data available in the literature. The first numerical simulations were conducted for mortars containing cement paste and sand as well as for concretes produced by adding granite to them. Two approaches were used to perform the simulations; in the first approach, a sample contained automata representing cement paste, sand, and granite, while in the second the automata represented mortar and granite. High consistency was achieved, with results from both approaches differing by only 0.6%. Subsequent simulations focused on concretes with different water-to-cement ratios (0.45, 0.55, and 0.65), the origin of the basaltic aggregate, and various aggregate contents (60%, 54%, 48%, and 42%). Results showed high agreement between simulations and experimental data, confirmed by a high coefficient of determination R² of 0.84 and mean squared error of 2.43 GPa². Finally, simulations were performed for lightweight expanded clay aggregate concrete, resulting in an R² of 0.86 and mean squared error of 0.81 GPa², which demonstrates the effectiveness of the MCA method in predicting the static elastic modulus of concrete. Full article

Foamed concrete, a lightweight material with excellent thermal insulation and low density, is increasingly popular in construction. This study uses the discrete element method (DEM) to simulate the compressive behavior of foamed concrete, analyzing the effects of particle radius, porosity, and void distribution. The results highlight the important role of geometric and material parameters. Smaller particle radii improve packing density and strength, while a uniform void distribution maximizes compressive strength by minimizing stress concentration. This information provides a basis for optimizing the design of foamed concrete for better mechanical performance and wider applications in sustainable construction. Full article

This study investigates the properties of structures with an ordered cellular internal configuration. Certain forms of the ordered internal structure contribute to the manifestation of auxetic properties. In this study, a hexagonal hourglass cell shape was chosen. The samples were 3D-printed with PLA and ABS filaments. The panels were subjected to out-of-plane compression. The Poisson ratio of the panels under compression was −0.06 for PLA samples and −0.05 for ABS samples. Tension tests were performed using two types of samples: type 1 with monolithic shoulders and type 2 with cellular shoulders. The average tensile strength of the type 1 samples was 0.482 ± 0.006 kN, whereas that of the type 2 samples was 0.416 ± 0.028 kN, which was 13.7% lower. The elongation at failure in the type 2 samples was 35% higher than that in the type 1 samples (1.85 ± 0.14 mm and 1.37 ± 0.08 mm, respectively). The higher deformation capacity of type 2 samples may be explained by the presence of an auxetic mesh over the entire sample. Auxetic properties are useful in numerous engineering fields. For civil engineering purposes, the blast-proof abilities of such structures are important. Thus, in future research, it is planned to create samples of fine-grain concrete with similar cellular structure. Full article

Sandwich panels, consisting of two concrete wythes that encase an insulating core, are designed to improve energy efficiency and reduce the weight of construction applications. This research examines the thermal and flexural properties of a novel sandwich panel that incorporates ultra-high-performance fiber-reinforced concrete (UHPFRC) and cellular lightweight concrete (CLC) as its core material. Seven sandwich panel specimens were tested for their thermo-flexural performance using four-point bending tests. The experimental parameters included variations in UHPFRC thickness (20 mm and 30 mm) and different shear connector types (shear keys, steel bars, and post-tension steel bars). The study also assessed the effects of adding steel mesh reinforcement to the UHPFRC layer and evaluated the performance of UHPFRC box sections without a CLC core. The analysis concentrated on several critical factors, such as initial, ultimate, and serviceability loads, load–deflection relationships, load–end slip, load–strain relationships, composite action ratios, crack patterns, and failure modes. The thermal properties of the UHPFRC and CLC were evaluated using a transient plane source technique. The results demonstrated that panels using post-tension steel bars as shear connectors achieved flexural performance, and the most favorable composite action ratios reached 68.8%. Conversely, the box section exhibited a brittle failure mode when compared to the other sandwich panels tested. To effectively evaluate mechanical and thermal properties, it is important to design panels that have adequate load-bearing capacity while maintaining low thermal conductivity. This study introduced a thermo-mechanical performance coefficient to evaluate both the thermal and mechanical performance of the panels. The findings indicated that sandwich panels with post-tension steel bars achieved the highest thermo-mechanical performance, while those with steel connectors had the lowest performance. Full article

In recent years, a kind of novel cellular concrete, fabricated by spherical saturated superabsorbent polymers, was developed. Its compressive behavior under high strain rate loadings has been studied by split Hopkinson pressure bar equipment in previous research, which revealed an obvious strain rate effect. It has been found by many researchers that the dynamic increase factor (DIF) of compressive strength for concrete-like materials measured by SHPB includes considerable structural effects, which cannot be considered as a genuine strain rate effect. Based on the extended Drucker–Prager model in Abaqus, this paper uses numerical SHPB tests to investigate structural effects in dynamic compression for this novel cellular concrete. It is found that the increment in compressive strength caused by lateral inertia confinement decreases from 5.9 MPa for a specimen with a porosity of 10% to 2 MPa for a specimen with a porosity of 40% at a strain rate level of 70/s, while the same decreasing trend was found at other strain rate levels of 100/s and 140/s. The lateral inertia confinement effect inside the cellular concrete specimen can be divided into the elastic development stage and plastic development stage, bounded by the moment dynamic stress equilibrium is achieved. The results obtained in this research can help to obtain a better understanding of the enhancement mechanism of the compressive strength of cellular concrete. Full article

This study investigated the removal of hydrogen sulfide (H₂S) from biogas using a laboratory-scale biofilter packed with biochar, cellular concrete waste (CLC waste), or polyurethane foam (PUF). The biofilter was tested under varied operational conditions, including H₂S concentrations ranging from 60 to 100 ppm and biogas flow rates of 0.2 to 1.0 L/min, to assess the removal efficiency and elimination capacity (EC). The COMSOL simulation framework was employed to predict biofilter performance and validate the experimental findings. The results revealed that removal efficiencies (REs) varied significantly across the packing materials and operational conditions. The biochar achieved RE values exceeding 92% and an EC of up to 150 g H₂S/m³/h, while the CLC waste demonstrated a moderate RE (~75%) and an EC of 100 g H₂S/m³/h. The PUF exhibited the lowest RE (~48%) but provided structural support for microbial colonization. Notably, the outlet (fourth and fifth) stages of the biofilter consistently outperformed the inlet stages (bottom and first stages), highlighting the influence of the residence time and microbial activity on H₂S removal. These findings provide a foundation for optimizing biofilter design and operational parameters to improve biogas purification efficiency. Full article

In order to investigate the steel fiber parameters on the damage characteristics and crack evolution of cellular concrete materials, uniaxial compression–acoustic emission combined tests were carried out on steel-fiber-reinforced cellular concrete (SFRCC) with different steel fiber contents (0%, 0.5%, 1%, 1.5%, and 2%) and different porosities (10% and 20%). The material damage evolution characteristics were analyzed by acoustic emission parameters and IB values, and the crack types were identified using Gaussian mixture clustering method (GMM) pairs. The results show the following: the inclusion of steel fibers increased the compressive strength of cellular concrete by 19.8~46.3% at 10% porosity, and by 37.1~102.2% at 20% porosity; the addition of steel fibers significantly increased the density and intensity of the acoustic emission signals; the decreasing tendency of the IB value at the peak stress slowed down with the increase in the amount of steel fibers, and the steel fibers could effectively inhibit the crack development; crack classification results show that the proportion of shear cracks in all stages of cellular concrete increased significantly after the addition of steel fibers. Full article

Cellular materials such as aluminum and polyurethane foams are recognized for their effectiveness in energy absorption. They commonly serve as crushable cores in sacrificial cladding for blast mitigation purposes. This study delves into the effectiveness of autoclaved aerated concrete (AAC), a lightweight, porous material known for its energy-absorbing properties as a crushable core in sacrificial cladding. The experimental set-up features a rigid frame made of steel measuring 1000 × 1000 × 15 mm³ with a central square opening (300 × 300 mm²) holding a 2 mm thick aluminum plate representing the structure. The dynamic response of the aluminum plate is captured using two high-speed cameras arranged in a stereoscopic configuration. Three-dimensional digital image correlation is used to compute the transient deformation fields. Blast loading is achieved by detonating 20 g of C4 explosive set at 250 mm from the plate’s center. The study assesses the mineral foam’s absorption capacity by comparing out-of-plane displacement and mean permanent deformation of the aluminum plate with and without the protective solution. Six foam configurations (A to F) are tested experimentally and numerically, varying in the foam’s free space for expansion relative to its total volume. Results show positive protective effects, with configuration F reducing maximum deflection by at least 30% and configuration C by up to 70%. Foam configuration influences energy dissipation, with an optimal lateral surface-to-volume ratio (ζ) enhancing protective effects, although excessive ζ leads to non-uniform foam crushing. To address the influence of front skin deformability, a non-deformable front skin has been adopted. The latter demonstrates an increased effectiveness of the sacrificial cladding, particularly for ζ values above the optimal value obtained when using a deformable front skin. Notably, using a non-deformable front skin increases maximum deflection reduction and foam energy absorption by up to approximately 30%. Full article

The relatively small tensile strength of concrete makes this material particularly vulnerable to cracking. However, the reality is that it is not always possible and practically useful to conduct studies on high-quality sealing cracks due to their inaccessibility or small opening width. Despite the fact that currently there are many technologies for creating self-healing cement composites, one of the most popular is the technology for creating a biologically active self-healing mechanism for concrete. It is based on the process of carbonate ion production by cellular respiration or urease enzymes by bacteria, which results in the precipitation of calcium carbonate in concrete. This technology is environmentally friendly and promising from a scientific and practical point of view. This research focuses on the technology of creating autonomous self-healing concrete using a biological crack-healing mechanism. The research methodology consisted of four main stages, including an analysis of the already conducted global studies, ecological and economic analysis, the prospects and advantages of further studies, as well as a discussion and the conclusions. A total of 257 works from about 10 global databases were analyzed. An overview of the physical, mechanical and operational properties of bioconcrete and their changes is presented, depending on the type of active bacteria and the method of their introduction into the concrete mixture. An analysis of the influence of the automatic addition of various types of bacteria on various properties of self-healing bioconcrete is carried out, and an assessment of the influence of the method of adding bacteria to concrete on the process of crack healing is also given. A comparative analysis of various techniques for creating self-healing bioconcrete was performed from the point of view of technical progress, scientific potential, the methods of application of this technology, and their resulting advantages, considered as the factor impacting on strength and life cycle. The main conditions for a quantitative assessment of the sustainability and the possibility of the industrial implementation of the technology of self-healing bioconcrete are identified and presented. Various techniques aimed at improving the recovery process of such materials are considered. An assessment of the influence of the strength of cement mortar after adding bacteria to it is also given. Images obtained using electron microscopy methods are analyzed in relation to the life cycle of bacteria in mineral deposits of microbiological origin. Current gaps and future research prospects are discussed. Full article

A versatile building material, foamed concrete is made of cement, fine aggregate, and foam combined with coarse aggregate. This study provides a description of how constant coarse aggregate replacement (50%) of LECA and foamed concrete, which are lightweight concrete types, by zeolite as a filler and PEG-400 as a plasticizer, water retention agent, and strength enhancer affect the mechanical properties of the cement. A study that examined the characteristics of cellular lightweight concrete in both its fresh and hardened forms was carried out for both foamed concrete and LECA concrete. In order to do this, a composite of zeolite and polyethylene glycol 400 was made using the direct absorption method, and no leakage was seen. Zeolite was loaded to a level of 10% and 20% of the total weight in cement, while 400 g/mol PEG was used at levels of 1%, 1.5%, and 2% of the cement’s weight. Various mixtures having a dry density of 1250 kg/m³ were produced. Properties like dry density, splitting tensile strength, and compressive strength were measured. An increase in the amount of PEG400–zeolite was seen to lower the workability, or slump, of both foamed and LECA concrete, while the replacement of aggregate by zeolite resulted in an exponential drop in both compressive and flexural strengths. Full article