Search Results (29)

Background/Objectives: Natural calcium carbonate materials such as Rügen chalk have a long history of use in balneology and rehabilitation, particularly for musculoskeletal disorders, yet their application remains largely confined to traditional, labour-intensive forms such as powders, suspensions, and packs, which limit usability and broader clinical translation. This study aimed to develop an alginate-based solid foam incorporating Rügen chalk and to evaluate how key formulation components influence its structural, mechanical, and thermal properties relevant for therapeutic use. Methods: Alginate–chalk foams were prepared by mechanical mixing of a sodium alginate–Rügen chalk paste with an amino acid-based surfactant, while in situ CO₂ generation from D–glucono–δ–lactone (GDL) induced calcium-mediated alginate gelation and foam stabilization. A central composite design with response surface methodology was used to assess the effects of alginate, chalk, and Perlastan^®–GDL content on foam pH, overrun, firmness, springiness, pore volume, sphericity, pore density, specific internal surface area, and heat-loss time. Foam microstructure was characterized by optical microscopy and microcomputed tomography (µCT), and the thermal conductivity and cooling behaviour of the selected formulation were compared with therapeutic peat. Results: Stable, elastic solid foams with a three-dimensional porous architecture were obtained across the investigated composition range. Foam overrun (30.8–57.1%) was primarily governed by sodium alginate and Rügen chalk concentrations, while firmness (7.4–15.2 N) increased predominantly with alginate content, and springiness remained high (70–78%), indicating good elastic recovery. Response surface modelling and ANOVA confirmed sodium alginate as the dominant factor influencing both mechanical and structural properties, with statistically significant effects on overrun, firmness, springiness, heat loss, porosity, and specific internal surface. µCT analysis revealed that all foam formulations were predominantly composed of fine, closed-cell pores, with over 96% of pores having volumes below 0.5 mm³ and a consistent median pore volume of 0.02 mm³. Structural differences between formulations were governed primarily by pore number and spatial distribution rather than pore size. Strong correlations were identified between µCT-derived parameters, particularly between specific internal surface, porosity, and pore density, confirming that internal architecture is controlled by pore population rather than individual pore dimensions. Thermal analysis demonstrated that the optimized formulation exhibited thermal conductivity comparable to therapeutic peat and maintained clinically relevant temperatures (35–45 °C) for more than one hour. Based on predefined performance criteria (overrun ≥ 50%, firmness ≤ 10 N, heat loss ≥ 120 s), formulation 7 was identified as optimal, combining favourable mechanical properties, structural uniformity and thermal retention. Conclusions: Alginate-based solid foams incorporating Rügen chalk constitute a feasible and tunable platform that combines efficient mineral loading, elastic porosity, and effective heat retention, offering a practical and modern alternative to conventional mineral-based therapeutic applications in balneology and rehabilitation. Full article

Groundwater is the primary source of livestock watering across the arid pasturelands of western Kazakhstan, yet no systematic field hydrochemical assessment has been published for this region in over 40 years. This study presents the first systematic field-based hydrochemical characterisation of groundwater sources used for pasture livestock watering in the West Kazakhstan Region and Aktobe Region, filling a critical data gap that has persisted since the Soviet era. Specifically, it characterises the hydrochemistry, water quality, and infrastructure condition of groundwater sources, and evaluates the groundwater resource potential against current and projected livestock water demand. A total of 139 groundwater samples were collected along 11,182 km of field routes during May–July 2025, and analysed for 25 physicochemical parameters; hydrochemical classification was performed using AquaChem 11, and spatial analysis was conducted in ArcGIS 10.8. The groundwater chemistry distribution is bimodal: fresh bicarbonate-calcium-magnesium waters (TDS < 3.0 g/L) constitute approximately 80% of samples, while highly mineralised chloride-sulphate-sodium waters (TDS up to 9.91 g/L) occur in salt-dome-influenced discharge zones. Nitrate concentrations exceeded 50 mg/L in 23–36% of samples, with maxima of 635 mg/L, reflecting intensive anthropogenic contamination near livestock facilities. Predictive exploitable fresh groundwater resources exceed current livestock demand by a factor of 162. The principal constraint on pasture water supply is not resource scarcity but the non-operational status of 51–75% of inspected watering infrastructure, a legacy of post-Soviet institutional collapse that requires urgent rehabilitation. Full article

The Ordovician system in the Shunbei area of the Tarim Basin hosts typical ultra-deep, fault-controlled fracture–vuggy hydrocarbon reservoirs. Compared with the surrounding Tabei and Tazhong areas, the genetic types of Ordovician formation water in Shunbei are more complex, and the relationships and spatial distribution of oil, gas, and water exhibit strong heterogeneity and pronounced fault control. This study systematically collected formation water geochemical and pressure data to clarify the geochemical characteristics and origin of Ordovician formation water in the Shunbei area and to investigate the indicative relationships between ion concentrations and ionic ratios of formation water and reservoir dolomitization, hydrocarbon migration, and accumulation. Research shows that, in contrast to the Tabei and Tazhong areas, the Ordovician formation water in Shunbei is predominantly of the calcium chloride (CaCl₂) type, with enrichment in Ca²⁺ and depletion in Mg²⁺, which may be related to euhedral dolomitization. In fault-controlled fracture–vuggy reservoirs, a high desulfurization coefficient—contrary to its interpretation in conventional reservoirs—corresponds to favorable zones for hydrocarbon accumulation. The rare earth element (REE) composition of the formation water is characterized by heavy REE enrichment, a distinct negative cerium (Ce) anomaly, and a positive europium (Eu) anomaly. Combined with hydrogen–oxygen and strontium isotopic data, these features indicate that the Ordovician formation water in Shunbei represents original depositional paleoseawater that has undergone cross-formational flow and concentration. The water bodies are divided into two distinct formation water systems bounded by the Shunbei No. 5 fault zone. Favorable zones for hydrocarbon enrichment are controlled by source rock distribution, and hydrocarbons migrate together with formation water along strike-slip faults within the Shunbei area, showing a northwest-to-southeast trend. The region between the middle segments of the Shunbei No. 4 and No. 8 fault zones is identified as a favorable area for hydrocarbon accumulation. Full article

The alpine grassland ecosystem of the Tibetan Plateau is a vital base for animal husbandry and a key ecological security barrier in China. Phosphorus (P), an essential nutrient, is among the primary factors limiting grassland productivity. However, the spatial distribution of soil P fractions across alpine grasslands on the Tibetan Plateau and their environmental drivers remain unclear, limiting our understanding of P cycling and grassland productivity. This study examined the composition and distribution of soil P in three representative alpine grasslands (meadow, steppe, and desert) using a combination of chemical fractionation and ³¹P nuclear magnetic resonance (NMR) spectroscopy. The results revealed pronounced spatial heterogeneity, with total soil P content varying by approximately 2.4-fold among the grassland types. Alpine meadows had the highest total P (0.73 g kg⁻¹) and available P (4.02 mg kg⁻¹) concentrations, with the latter being nearly twice that of alpine steppes and deserts. Alpine meadows were characterized by a predominance of labile and moderately labile organic P (e.g., NaOH-Po) and a diverse array of phosphate monoesters and diesters, whereas alpine deserts were dominated by stable, calcium-bound inorganic P (HCl-Pi). Temperature, precipitation, pH, and phosphatase activity were identified as key factors regulating the distribution and transformation of P fractions. The distinct P fractions and availability uncovered in this study are essential for predicting grassland ecosystem responses to environmental change and guiding sustainable pasture management on the Tibetan Plateau. Full article

The longevity, site fidelity, and trophic position of freshwater turtles have led to their increasing recognition as useful bioindicators of environmental contamination. Mauremys leprosa (n = 25) shells from a Northern African wetland system were examined for trace element concentrations in order to assess shell composition as a non-invasive biomonitoring method. Micro x-ray fluorescence (μXRF) method was used to measure the shell concentrations of 17 elements, including Ca, P, Fe, Zn, Mn, Sr, Pb, Sb, and Al. As would be expected from the structural composition of bony tissues, calcium and phosphorus were the predominant constituents. In addition to bulk concentrations, micro-XRF elemental mapping revealed heterogeneous spatial distributions of essential and toxic elements within the shells, providing visual evidence of bioaccumulation patterns and supporting the use of shells as non-invasive bioindicators. There were statistically significant sex-related differences in the levels of trace elements, with males exhibiting higher concentrations of Mg, Mn, Sb, Pb, and Al (p < 0.05). Spearman correlations revealed strong associations between certain shell elements (e.g., Fe, Mn, Ti, Zn) and morphometric parameters. Comparisons with environmental samples (water and sediment) showed moderate to strong correlations, particularly with sediment metal concentrations, supporting the utility of shell chemistry as an integrative exposure matrix. Nonetheless, there were significant percentages of censored or missing values for certain metals (Cu, Ni, and As). This study emphasizes how viable turtle shells are as non-lethal markers of bioaccumulation and stresses how crucial it is to take environmental matrices, element-specific variability, and sex into account when assessing contamination. Longitudinal monitoring, physiological biomarkers, and isotopic analysis should all be used in future studies to bolster the causal relationships between environmental exposure and turtle health. Full article

The growing global demand for food has driven an increase in both swine and agricultural production, although swine wastewater poses a significant environmental risk. This study employed elemental mapping techniques to evaluate the effects of swine wastewater irrigation on the spatial distribution and concentration of essential and non-essential elements, as well as on the morphological responses of habanero pepper (Capsicum chinense Jacq.) seedlings. Six treatments were tested, ranging from 0% to 100% swine wastewater (T1 = 20%, T2 = 40%, T3 = 60%, T4 = 80%, T5 = 100%, and T6 = control with conventional fertilization), using a completely randomized design with five replications. Emergence, elemental distribution, morphology, and seedling quality were evaluated. The highest emergence percentages and rates were observed in the 20% wastewater treatment and the control groups. Diluted wastewater treatments promoted potassium and calcium uptake, which correlated with improved seedling growth and vigor, while irrigation with 100% wastewater led to excessive chlorine and sulfur accumulation, negatively affecting morphology. These results indicate that the controlled dilution of swine wastewater optimizes nutrient availability and seedling development, offering an environmentally sustainable alternative for producing high-quality habanero pepper seedlings. This study provides novel insights into the environmental implications of swine wastewater reuse through elemental mapping, underscoring its potential to support sustainable and regenerative agriculture. Full article

Resorbable microparticles can be added to hydrogel-based biocompatible scaffolds to improve their mechanical characteristics and allow localised drug delivery, which will aid in tissue repair and regeneration. It is well-known that bioprinting is important for producing scaffolds personalised to patients by loading them with their own cells and printing them with specified shapes and dimensions. The question is how the addition of such particles affects the rheological responsiveness of the hydrogels (which is critical during the printing process) as well as mechanical parameters like the elastic modulus. This study tries to answer this question using a specific system: an alginate-gelatine hydrogel containing polyhydroxybutyrate-co-hydroxyvalerate (PHBV) microparticles. Scaffolds were made by bioprinting and moulding incorporating PHBV microspheres (7–12 μm in diameter) into alginate–gelatine inks (4.5 to 9.0% w/v). The microparticles (MP) were predominantly located within the polymeric matrix at concentrations up to 10 mg MP/mL ink. Higher particle concentrations disrupted their spatial distribution. Inks pre-crosslinked with 15 mM calcium and containingMPat concentrations ranging from 0 to 10 mg/mL demonstrated rheological characteristics appropriate for bioprinting, such as solid-like behaviour (G′ = 1060–1300 Pa, G″ = 720–930 Pa), yield stresses of 320–400 Pa, and pseudoplastic behaviour (static viscosities of 4000–5600 Pa·s and ~100 Pa·s at bioprinting shear rates). Furthermore, these inks allow high printing quality, assessed through scaffold dimensions, filament widths, and printability (Pr > 0.94). The modulus of elasticity in compression (E) of the scaffolds varied according to the content of MP and the manufacturing technique, with values resembling those of soft tissues (200–600 kPa) and exhibiting a maximum reinforcement effect with 3 mg MP/mL ink (bioprinted E = 273 ± 28 kPa; moulded E = 541 ± 66 kPa). Over the course of six days, the sample’s mass and shape remained stable during degradation in simulated body fluid (SBF). Thus, the alginate–gelatine hydrogel loaded with PHBV microspheres inks shows promise for targeted drug delivery in soft tissue bioengineering applications. Full article

Rivers in plateau regions are more vulnerable to human activities and climate change than those in plains due to cold climate and high altitude. Studying the temporal and spatial distribution of phosphorus against the backdrop of climate warming and human activities is of great significance for the protection of the ecological environment of plateau rivers. This study focuses on the Yarlung Zangbo River, one of the highest-altitude rivers in the world, analyzing the different forms of phosphorus and total dissolved organic carbon (TOC) concentration and distribution characteristics in sediments and sediment–water interfaces at different time and spatial scales. The analysis indicators include total phosphorus (TP) and dissolved total phosphorus (DTP) in the water body; ammonium chloride-extractable phosphorus (NH₄Cl-P), iron-bound phosphorus (Fe-P), calcium-bound phosphorus (Ca-P), aluminum-bound phosphorus (Al-P), organic phosphorus (OP), and TOC concentration and distribution in sediments. The results showed that the upstream and downstream sections of the Yarlung Zangbo River have relatively good water quality, while the middle stream section, affected by human activities, has higher phosphorus and TOC content in the water body. The phosphorus in the sediments is mainly in the form of Ca-P, indicating that the primary natural phosphorus input is through the disintegration of salts. During the freeze–thaw cycle, the organic matter in the sediments affects the phosphorus content in the water through adsorption and release. Climate warming is expected to increase the phosphorus load in the Yarlung Zangbo River. Comparative studies between plateau rivers and plains rivers have revealed that exogenous particulate phosphorus and endogenous phosphorus converted with the facilitation of organic matter are the main sources of eutrophication risk in plateau rivers. This study unveils the temporal and spatial distribution characteristics of phosphorus and TOC in the Yarlung Zangbo River, and discusses the mechanisms affecting phosphorus concentrations in key plateau river nutrient elements, providing scientific support for the protection of the fragile ecological environment of plateau river ecosystems. Full article

Workers’ health is jeopardized in steel rolling workshops due to the production of particulate matter. These particles’ physicochemical properties have a direct impact on their effects on human health, emphasizing the importance of understanding these properties for exposure control. This study investigated particulate matter emissions in hot and cold steel rolling workshops, focusing on mass concentrations, particle size distributions, and elemental compositions. The findings revealed that particles predominantly range from 0.3 to 1.0 μm in size, with irregular block-like and fibrous morphologies. Elemental analysis showed distinct compositions: the main components in the hot rolling workshop were oxygen, calcium, silicon, carbon, and iron while those in the cold rolling workshop were oxygen, silicon, aluminum, carbon, and iron. The particulate matter concentrations were higher in the hot rolling workshop than in the cold rolling workshop. The Rosin–Rammler particle size distribution function was applied to characterize particle size distribution at emission sources. This paper highlights the dynamic variations and spatial distribution patterns of particulate matter during rolling processes, providing key data for understanding particulate matter behavior in industrial environments and informing targeted pollution control strategies. Full article

Monitoring groundwater pollution is an important issue in terms of analyzing threats to protected, environmentally valuable areas. The topographical and environmental characteristics of a given area are often mentioned among the factors affecting the dynamics and chemistry of groundwater. In this study, the random forest regression (RFR) model was used to determine the spatial distribution of selected metals, such as aluminum, calcium, iron, potassium, magnesium, manganese, sodium, and zinc. In the role of indicators describing terrain variability, derivatives of the digital elevation model (DEM) were employed, with a spatial resolution of 5 m, describing the topography of the terrain on a local scale, such as, among others, slopes, the aspect and curvatures of slopes, the topographic position index, and the SAGA wetness index, as well as generalized values determined for each sampling point of the areas contributing their runoff. In addition, environmental parameters were taken into consideration: forest habitat types, the structure of soil cover, and the seasons when samples were collected. This study used samples collected from 15 wells located in forested areas of the Wielkopolska National Park on seven dates. The results obtained show that random forest can be used with very good results to model the spatial variability of the concentrations of aluminum, potassium, magnesium, manganese, and sodium in groundwater. However, in the case of calcium and zinc, no correlations were found between the adopted indicators describing the spatial variability of the area and their concentrations in groundwater. In addition, the degree of importance of each predictor was determined in order to rank their importance in modeling the concentration of each of the metals in groundwater. The summary ranking of predictors indicates that the strongest influence on the predicted concentration of metals in groundwater is exhibited by profile curvatures, planar curvatures, multiscale TPI, and then the habitat type of the forest. On the other hand, curvature classifications, soil composition, and seasonality exhibit the smallest generalized impact on the results of modeling. Full article

Phyllostachys edulis, an economically and ecologically significant bamboo species, has substantial research value in applications as a bamboo substitute for plastic and in forest carbon sequestration. However, frequent seasonal low-temperature events due to global climate change affect the growth, development, and productivity of P. edulis. Calcium signaling, serving as a versatile second messenger, is involved in various stress responses and nitrogen metabolism. In this study, we analyzed the calcium signaling dynamics and regulatory strategies in P. edulis under chilling stress. Differentially expressed genes (DEGs) from the CBF families, AMT families, NRT families, and Ca²⁺ sensor families, including CaM, CDPK, and CBL, were identified using transcriptomics. Additionally, we explored the law of Ca²⁺ flux and distribution in the roots of P. edulis under chilling stress and validated these findings by assessing the content or activity of Ca²⁺ sensor proteins and nitrogen transport proteins in the roots. The results indicated that the Ca²⁺ sensor families of CaM, CDPK, and CBL in P. edulis exhibited significant transcriptional changes under chilling stress. Notably, PH02Gene03957, PH02Gene42787, and PH02Gene19300 were significantly upregulated, while the expressions of PH02Gene08456, PH02Gene01209, and PH02Gene37879 were suppressed. In particular, the expression levels of the CBF family gene PH02Gene14168, a downstream target gene of the calcium channels, increased significantly. P. edulis exhibited an influx of Ca²⁺ at the root, accompanied by oscillating negative peaks under chilling stress. Spatially, the cytosolic calcium concentration ([Ca²⁺]_cyt) within the root cells increased. The CIPK family genes, interacting with Ca²⁺-CBL in downstream signaling pathways, showed significant differential expressions. In addition, the expressions of the NRT and AMT family genes changed correspondingly. Our study demonstrates that Ca²⁺ signaling is involved in the regulatory network of P. edulis under chilling stress. [Ca²⁺]_cyt fluctuations in the roots of P. edulis are induced by chilling stress, reflecting an influx of extracellular Ca²⁺. Upon binding to Ca²⁺, downstream target genes from the CBF family are activated. Within the Ca²⁺–CBL–CIPK signaling network, the CIPK family plays a crucial role in nitrogen metabolism pathways. Full article

Placental health and foetal development are dependent upon element homeostasis. Analytical techniques such as mass spectroscopy can provide quantitative data on element concentrations in placental tissue but do not show spatial distribution or co-localisation of elements that may affect placental function. The present study used synchrotron-based X-ray fluorescence microscopy to elucidate element content and distribution in healthy and pathological placental tissue. The X-ray fluorescence microscopy (XFM) beamline at the Australian Synchrotron was used to image trace metal content of 19 placental sections from healthy term (n = 5, 37–39 weeks), foetal growth-restricted (n = 3, <32 weeks, birth weight <3rd centile), postdate (n = 7, >41 completed weeks), and stillbirth-complicated pregnancies (n = 4, 37–40 weeks). Samples were cryo-sectioned and freeze-dried. The concentration and distribution of fourteen elements were detected in all samples: arsenic, bromine, calcium, chlorine, copper, iron, molybdenum, phosphorous, potassium, rubidium, selenium, strontium, sulphur, and zinc. The elements zinc, calcium, phosphorous, and strontium were significantly increased in stillbirth placental tissue in comparison to healthy-term controls. Strontium, zinc, and calcium were found to co-localise in stillbirth tissue samples, and calcium and strontium concentrations were correlated in all placental groups. Molybdenum was significantly decreased in stillbirth, foetal growth-restricted, and postdate placental tissue in comparison to healthy-term samples (p < 0.0001). Synchrotron-based XFM reveals elemental distribution within biological samples such as the placenta, allowing for the co-localisation of metal deposits that may have a pathological role. Our pilot study further indicates low concentrations of placental molybdenum in pregnancies complicated by foetal growth restriction, postdate delivery, and stillbirth. Full article

This study aimed to characterize the chemical composition and spatial distribution of groundwater in the Kızılırmak Delta of Turkey and to evaluate the suitability of groundwater in the Kızılırmak Delta for drinking water use through a Water Quality Index (WQI) assessment. Eleven water parameters, including nitrate (NO₃⁻), calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), chloride (Cl⁻), potassium (K⁺), bicarbonate (HCO₃⁻), sulfate (SO₄²⁻), hardness (measured as CaCO₃), electrical conductivity (EC), and pH were analyzed to determine the water quality of each groundwater sample. The WQI was determined using the weighted arithmetic index method and the method specified by the Canadian Council of Ministers of the Environment (CCME). The spatial distribution of the result for all observation wells was plotted. Principal Component Analysis (PCA) was generated utilizing the analytical data from eleven selected samples. As a result of the study, according to the calculated WQI values, the water in most of the wells was not suitable for drinking purposes. The minimum Ca²⁺ concentration in the study area was 108,817 mg/L, and the maximum was 692,382 mg/L, which showed that the samples in all wells exceeded the WHO limit. The same situation is valid for Mg²⁺, and the values vary between 100.383 and 5183.026 mg/L. From the spatial distribution of the water quality parameters it has been understood that the eastern part of the region is more suitable than the western part for drinking purposes. The results from correlation analysis showed the strongest positive correlation between Mg²⁺ and Na⁺ and Na⁺ and EC as 0.989. The present study shows that the groundwater of the delta, which has deteriorating water quality, should be treated before it is used for drinking water and protected from contamination hazards. Full article

Clogging of the landfill drainage layer leads to a high leachate head developing over the bottom liner, which increases the risk of leachate leakage. Estimation of the maximum leachate head in the landfill drainage layer is of great significance to the pollution control of bottom liners. In this study, a simplified model considering the development of clogging is established through assuming the spatial and temporal distributions of clogging in a drainage layer of landfill. The calculation results are compared with a previous study to verify the proposed model. Through parameter analysis, it is discovered that the larger the initial hydraulic conductivity, the less the influence of clogging on the leachate head at the beginning, but it will increase over time. Meanwhile, a longer drainage distance, a larger inflow rate, or a higher ion concentration will lead to a greater influence of clogging on the leachate head. The completion time of clogging is more sensitive to the variation of inflow rate and ion concentration. In order to effectively control the maximum leachate head, it is suggested that the drainage material with large hydraulic conductivity such as pebbles or gravel should be used, the drainage slope should be greater than 4%, the drainage distance should be controlled at 20 m, and calcium products should be removed from leachate through adsorption, precipitation, or waste reuse. Full article

The cytosolic concentration of free calcium ions ($\left[{\mathrm{Ca}}^{2+}\right]$) is an important intracellular messenger in most cell types, and the spatial distribution of $\left[{\mathrm{Ca}}^{2+}\right]$ is often critical. In a salivary gland acinar cell, a polarised epithelial cell, whose principal function is to transport water and thus secrete saliva, $\left[{\mathrm{Ca}}^{2+}\right]$ controls the secretion of primary saliva, but increases in $\left[{\mathrm{Ca}}^{2+}\right]$ are localised to the apical regions of the cell. Hence, any quantitative explanation of how $\left[{\mathrm{Ca}}^{2+}\right]$ controls saliva secretion must take into careful account the spatial distribution of the various ${\mathrm{Ca}}^{2+}$ sources, ${\mathrm{Ca}}^{2+}$ sinks, and ${\mathrm{Ca}}^{2+}$-sensitive ion channels. Based on optical slices, we have previously constructed anatomically accurate three-dimensional models of seven salivary gland acinar cells, and thus shown that a model in which ${\mathrm{Ca}}^{2+}$ responses are confined to the apical regions of the cell is sufficient to provide a quantitative and predictive explanation of primary saliva secretion. However, reconstruction of such anatomically accurate cells is extremely time consuming and inefficient. Here, we present an alternative, mostly automated method of constructing three-dimensional cells that are approximately anatomically accurate and show that the new construction preserves the quantitative accuracy of the model. Full article