In this study the development and radiological validation of a custom-designed orbital anthropomorphic phantom was investigated. The phantom was intended to accurately reproduce the radiodensity of key oculo-orbital tissues in computed tomography (CT). The phantom was fabricated using epoxy-resin-based composites modified with calcium carbonate, acetone, and sodium bicarbonate to achieve tissue-equivalent attenuation properties. Four representative tissues-orbital bone, crystalline lens, extraocular muscle, and optic nerve-were simulated to obtain optimized material compositions. CT images were produced on a clinical scanner under standardized conditions (80-120 kV), and Hounsfield Unit (HU) values were measured using a consistent region-of-interest (ROI) methodology. The results were compared with those obtained from a commercial reference phantom (CIRS ATOM Adult Phantom) and a clinical dataset of 256 adult brain CT images, providing statistically robust reference values. The developed phantom demonstrated strong agreement with clinical data, particularly for soft tissues, with relative differences of - 3.83% for the eye lens, - 3.63% for muscle, and + 3.49% for the optic nerve. In contrast, the commercial phantom showed significant discrepancies for soft tissues, including - 48.31% for the eye lens and + 30.62% for the optic nerve, due to its homogeneous material composition. Both phantoms accurately reproduced bone radiodensity, with relative differences remaining below 5%. Furthermore, the developed phantom preserved tissue-specific HU differentiation across varying tube voltages, reflecting realistic energy-dependent behavior consistent with X-ray interaction mechanisms. Overall, the developed phantom provides a realistic radiological representation of the orbital region and a promising experimental platform for CT imaging and dosimetric applications, while further validation across different CT systems and acquisition protocols is warranted to establish its broader applicability.

Ocean acidification, driven by the absorption of anthropogenic carbon dioxide into seawater, poses a significant threat to marine environments and biodiversity. This comprehensive review examines the specific impacts of acidification on the reproductive physiology of fish, integrating recent advances in our understanding of gonadal development, gametogenesis, and early embryonic development. We synthesize current findings on how altered carbonate chemistry disturbs the reproductive system from gametogenesis and fertilization to larval development and beyond. Our analysis reveals that ocean acidification affects multiple physiological pathways, including disruption of the hypothalamic-pituitary-gonadal (HPG) axis, impairment of calcium signaling, and alterations in sex hormone synthesis. We propose a mechanistic model in which pH reduction may weaken Dax1-mediated repression of P450arom transcription, thereby dysregulating aromatase activity and leading to sex hormone imbalance that impairs gonadal development; however, this proposed mechanism requires direct experimental validation under ocean acidification, as the net outcome may be modulated by additional regulatory layers such as epigenetic modifications and other transcription factors. Furthermore, we discuss the synergistic effects of ocean acidification with temperature elevation and other stressors, which often exacerbate reproductive dysfunction. This review concludes that no multi-generational study has yet evaluated HPG axis disruption to population-level recruitment failure, a critical gap for fishery resource assessment. We emphasize the critical importance of multi-generational and field-based studies to fully understand these impacts, which is essential for forecasting consequences for global marine biodiversity and the long-term sustainability of fisheries.

Global phosphogypsum (PG) discharge exceeds 300 million tons annually, and its massive stockpiling or marine disposal poses serious threats to the ecological environment. To address the need for high-value utilization of PG, this study proposes a short-route process of "carbonation conversion-ammonium chloride roasting-metathesis" for the preparation of high-purity calcium sulfate whiskers. After PG pre-neutralization with lime milk to pH 8.5, ammonium carbonate is used as the carbonation agent to convert CaSO4·2H2O to CaCO3 with a conversion of 97.4%, while the released fluoride is immobilized as CaF2. The CaCO3-bearing slag is roasted with NH4Cl at 600 °C for 60 min (CaCO3 reaction efficiency 97.2%), and the resulting CaCl2 solution and (NH4)2SO4 solution are used as the calcium and sulfur sources for the subsequent metathesis crystallization. Under optimized conditions (Ca 66.58 g/L, S 53.30 g/L, pH ≈ 6, 50-60 °C, 0.3 g/L Mg[2+]), calcium sulfate dihydrate (CaSO4·2H2O) whiskers with a length/diameter aspect ratio above 60 and a purity above 98 wt% are obtained; XRD (PDF #33-0311) and elemental analyses confirm the dihydrate crystalline phase and a strong preferred orientation along the [010] axis. Overall recoveries of Ca (PG → CaCl2 solution) and S (PG → (NH4)2SO4 solution) are 94.3% and 97.4%, respectively, and the process reduces the residual solid waste from 200 g of PG to only 21 g of F-enriched residue, i.e., an 89.5% solid-waste reduction. The ammonium salt medium is internally recycled, forming a closed loop of Ca, S and NH4[+].

Calcium carbonate (CaCO3) is a common soil amendment to alleviate cadmium (Cd) transformation and accumulation in brown rice, and tetraconazole is a widely used chiral pesticide to control rice sheath blight. This study investigated the effects of soil amendment CaCO3 and chiral pesticide tetraconazole on pesticide residues, Cd accumulation, and soil microorganisms in two rice cultivars (ZG 96 with low Cd accumulation and ZY 18 with high Cd accumulation) in Cd-contaminated paddy fields. Results showed that CaCO3 significantly reduced Cd concentrations in brown rice by 60.0-82.9%. It altered tetraconazole degradation half-lives in rice plants, increased residues in ZG 96 rice husk, and decreased enantioselectivity in soil. Tetraconazole residues in brown rice were lower in ZY 18 than in ZG 96. Both CaCO3 and tetraconazole reshaped soil microbial diversity, community structure, and metabolic functions, with distinct responses between the two rice cultivars. All residues of tetraconazole and Cd in brown rice were below maximum residue limits. The rice cultivar differences should be considered under the application of amendments and chiral pesticides, and this study would provide valuable data and theoretical basis for their combined treatments.

Background: Vaterite calcium carbonate (CaCO3) particles are promising pH-sensitive carriers for oral drug delivery, but the influence of drug hydrophilicity on loading and release is still not well defined. In this study, we evaluate the encapsulation and release profiles of six specific formulations utilizing metformin and meloxicam across distinct CaCO3 carrier variants and loading methodologies. Methods: We prepared vaterite CaCO3 particles as native (and PVP-stabilized) carriers and utilized co-precipitation, post-loading (adsorption), and sonication-assisted loading techniques. We subsequently evaluated carrier morphology, phase stability, encapsulation efficiency, surface adsorption capacity, and in vitro drug release in simulated gastric (pH 1.2) and intestinal (pH 6.8) media. Results: Quantitative image analysis confirmed that porous vaterite particles formed primarily in the micron range, with PVP stabilization significantly reducing the mean particle diameter compared to native carriers (0.966 µm versus 1.189 µm). Furthermore, extended exposure to aqueous media induced partial transformation to calcite. The highest encapsulation efficiency for metformin (93.0 ± 1.5%) was achieved using co-precipitation, whereas for meloxicam (79.6 ± 1.9%), it was optimized through sonication-assisted adsorption on the PVP-modified carriers. In vitro release showed a clear pH-dependent behavior; the fast dissolution of the vaterite through gastric pH was associated with the fast release of metformin, especially in the calcite-containing formulation that produced the greatest release (98.0 ± 3.3%) in 15 min. At intestinal pH, metformin and meloxicam exhibited sustained release as in the Korsmeyer-Peppas model. Conclusions: The evaluated carrier compositions and loading methodologies distinctly influenced the encapsulation and release profiles of the six prepared formulations. These specific formulation comparisons highlight practical considerations for utilizing vaterite carriers for varied release targets.

Background/Objectives: Solid self-nanoemulsifying drug delivery systems (SNEDDS) prepared by adsorption onto porous carriers are widely used to improve the oral delivery of poorly water-soluble drugs. However, this approach is limited by increased dosing volume and incomplete drug release. This study aims to develop a thermoresponsive in situ salified SNEDDS (T-IS-SNEDDS) that simultaneously prevents formulation leakage and overcomes the release limitations of conventional adsorption-based solidification. Methods: Excipients were selected by solubility screening of oils and surfactants. Sodium and calcium carbonate were evaluated for in situ salt formation. Adsorption-based solid SNEDDS and thermoresponsive formulations containing poloxamer 188 with propylene glycol or polyethylene glycol 400 were prepared. Droplet size was measured after aqueous dilution. Solid-state characterization used scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and powder X-ray diffraction. In vitro dissolution performance was evaluated against the raw drug and adsorption-based formulations. Results: Imwitor 308 and Tween 80 exhibited the highest solubilization capacities. Sodium carbonate (10 mg/g) markedly increased the solubility of olmesartan medoxomil from 4.11 ± 0.11 to 46.01 ± 1.92 mg/g. Although liquid in situ salified SNEDDS achieved rapid dissolution (94.2 ± 1.8% at 10 min), adsorption-based solidification required four capsules and yielded incomplete drug release (67.76 ± 3.18%). Both thermoresponsive formulations accommodated the therapeutic dose in a single capsule and released ≈95% of the drug within 60 min. Conclusions: The combined in situ salified drug loading and thermoresponsive matrix strategy successfully enables single capsule administration while overcoming the incomplete release of adsorption-based solid SNEDDS.

Acquiring an amphiphobic nanocalcium carbonate (NCC) is a perplexing problem in the long term because of its hydrophility. This restricts its application in self-cleaning coatings and other super-low surface energy engineering fields. This study offers a novel and simple approach that endows NCC with an amphiphobic property through surface modification using perfluoropolyether carboxylic acid in the presence of sodium hydroxide. The modification process was optimized at a 5 wt% modifier concentration, 50 °C, and a duration of 40 min. Comprehensive characterization was performed using FT-IR, TG-DTA, SEM, HR-TEM, NMR and XPS techniques, in contrast with the previous literature describing hydroxyl groups. Notably, FT-IR analysis indicates that no hydroxyl groups were detected on the NCC surface. The modification mechanism involves COO- groups from the modifier forming Ca-O ionic bonds with calcium sites on the NCC surface. HR-TEM analysis revealed an exceptionally thin modifier film (2-5 nm) on the NCC surface. Despite this minimal thickness, it endows NCC with remarkable amphiphobic properties, with water and oil contact angles up to 120.4° and 139.9°, respectively. These findings expand insights into the surface modification mechanism of NCC and its potential application fields.

As a class of low-cost and broad-spectrum antibiotics in wide aquaculture use, residues of tetracyclines (TCs) are imperiling aquatic organisms and public health worldwide, leading to a high demand for TC removal from the aquaculture environment. In addition, considerable consumption of thick-shell mussels generates massive mussel shell waste, and their treatment has been an economic and environmental issue. Herein, a low-cost and high-efficiency mussel shells-based material was successfully prepared for TC removal by thermal modification of shell waste of Mytilus coruscus. Morphological and structural characterizations revealed the phase transformation of calcium carbonate to calcium oxide. The shell-based material calcined at 1050 °C (MC1050) yielded a Langmuir-fitted maximum removal capacity (qm) of 68.0 mg/g towards oxytetracycline (OTC). Thermodynamic calculations indicate that OTC removal by MC1050 is a spontaneous and endothermic process. OTC removal by MC1050 is likely achieved via multiple co-existing pathways, where Ca-OTC co-precipitation driven by CaO-phase hydration and resultant high-pH conditions dominates, accompanied by auxiliary surface-interaction contributions. Furthermore, MC1050 achieves removal efficiencies exceeding 96% for the ten target TCs spiked at 20 μg/L in real-world freshwater and marine aquaculture effluent matrices. Overall, the developed shell-based material shows promising performance for wastewater treatment and facilitates the resource utilization of waste mussel shells.

To elucidate the influence of mineral composition on CO2 mineralization and mechanical reinforcement, three synthetic tailing systems representing felsic, high-calcium silicate, and magnesium-carbonate compositions were prepared using a full-component reconstitution approach. Their carbonation kinetics, phase evolution, pore structure, and mechanical response were systematically investigated. The alkaline buffering duration increased in the order of felsic < high-calcium silicate < magnesium-carbonate types, with plateau durations of approximately 300, 650, and 2000 s, respectively. TG-DTG, XRD, and FTIR analyses collectively indicated composition-dependent formation of carbonate-bearing products, with the magnesium-carbonate type showing the strongest carbonate-related signals. SEM observations further revealed precipitation on particle surfaces and within interparticle regions, suggesting precipitation-induced particle bonding. Nitrogen adsorption-desorption measurements showed pronounced pore-structure reorganization after mineralization; the average pore size converged to approximately 7.5-7.9 nm, whereas the specific surface area decreased in all systems. The failure loads of the felsic and high-calcium silicate types increased by factors of 2.97 and 3.81, respectively. The mineralized magnesium-carbonate type exhibited the highest apparent compressive strength (53.69 kPa). These results demonstrate clear composition-dependent relationships among carbonation, pore evolution, and mechanical response in the synthetic systems. Because the materials were prepared from analytical-grade reagents and no complete carbon balance was established, the results should be regarded as mechanistic model-system evidence rather than quantitative estimates of CO2 sequestration in natural tailings.

Lead (Pb) contamination in erosion-prone soils presents a dual environmental issue because it causes concurrent pollution and soil degradation. We developed a sustainable bioremediation technique utilizing microbially induced calcium carbonate precipitation (MICP) with the indigenous Pb-tolerant ureolytic bacterium Sporosarcina pasteurii, isolated from the biological soil crusts of the Qinghai-Tibet Plateau. The strain exhibited considerable urease activity and consistent growth under extreme lead stress (2000 mg/L) and effectively facilitated carbonate mineralization. The MICP treatment resulted in the formation of a continuous CaCO3 layer within the soil profile, significantly enhancing mechanical stability and decreasing sediment yield by 77.6-92.5% across different slopes (45° and 70°) and rainfall intensities (6 and 18 mm). Simultaneously, MICP significantly altered Pb migration dynamics by retaining Pb in the upper soil layer and restricting the transport of dissolved and particulate Pb via runoff and erosion. BCR sequential extraction demonstrated a shift of Pb from the mobile weak-acid extractable and reducible fractions to the more stable residual and oxidizable fractions. Pb immobilization was associated with MICP-induced carbonate mineralization, crystal bridging, particle encapsulation, and pore filling, and incorporation into Pb-bearing mineral phases. Subsequent multivariate analysis revealed that Pb retention and erosion resistance were mostly governed by CaCO3 accumulation and soil stabilization. This study proposes a multiscale mechanism of self-reinforcing physical reinforcement-chemical fixation synergy and demonstrates the potential of MICP as a nature-based solution for remediating heavy metal-contaminated, erosion-prone slopes in cold and ecologically fragile regions.

Biogenic marine carbonate production is a key component of the global carbon cycle, with shelf environments contributing disproportionately to global CaCO3 production. Yet, empirical data remain scarce for many shelf habitats, including globally widespread coralline algal beds (CABs; rhodolith and maerl beds), formed by free-living coralline algae (rhodoliths sensu lato). Moreover, available CAB-associated carbonate production estimates remain poorly integrated across spatial scales, limiting assessments of their broader relevance. Here, we quantified rhodolith growth, through alizarin staining, and carbonate production of three northeastern Atlantic CABs and incorporated those estimates into a global dataset. We then scaled compiled rates by known CAB area to assess total carbonate production rates across spatial scales and compared CABs with other major carbonate producers. Rhodolith growth and carbonate production rates in the study region fell within the range reported for other temperate CABs, while CAB production rates globally varied widely across climatic zones (0.04-2.1 kg CaCO3 m[-2] year[-1]). When scaled to individual CAB areal extents, total carbonate production ranged from 5 t to 0.025 Gt year[-1]. At larger spatial scales, available ecoregion-level estimates, representing ~70% of estimated global CAB area, yielded a total of 0.31-1.85 Gt CaCO3 year[-1]. Although area-based CAB production rates were generally lower than those of coral reefs, their broader distribution resulted in total carbonate production estimates that overlap with those for shallow tropical coral reefs and exceed those for calcareous green algae. Altogether, spatial scaling highlights CABs as local and regional carbonate-production hotspots that may contribute substantially (7%-44%) to global shelf carbonate production. However, while these estimates provide a first larger-scale approximation of CAB-associated carbonate production, it should be considered that they represent gross production and should therefore not be interpreted as net carbonate budgets. Better constraining the contribution of CABs to global carbonate cycling will require quantifying carbonate losses and accumulation, together with expanding the spatial coverage of production data.

The strategy of adding mycotoxin binders (MTBs) to feed lactating cows to reduce the absorption of aflatoxins (AFs) in the gastrointestinal tract and reduce milk contamination by hydroxylated AF compounds, especially AFM1, to below the maximum contaminant level (MCL) has become widespread. However, the indiscriminate use of MTBs is very common. The objective of the study was to determine, under field conditions, the efficacy of an MTB in reducing AFM1 contamination in cow's milk. Feed and raw milk were evaluated on-farm using lateral flow immunochromatography devices. In a 2 × 2 Latin square design, in two separate test periods, two diets were administered consecutively to each of twelve Holstein cows (multiparous, 220 ± 20 lactation days): 1: Basal diet naturally contaminated (120 AFB1 µg/d); 2: Basal diet plus an MTB (calcium carbonate and yeast fragments; 150 g/d). MTB intake effectively reduced the mean concentration, daily excretion, and percentage transfer rate of AFM1 in milk (0.724 ± 0.045 to 0.479 ± 0.055 µg/kg, p < 0.01; 15.6 ± 1.7 to 9.7 ± 1.5 µg/d, p < 0.05; and 13.0 ± 1.4 to 8.1 ± 1.3%, p < 0.05, respectively). These results highlight the need to evaluate, under field conditions, the effectiveness of MTBs as part of a mycotoxin contamination control program on dairy farms.

The deep sea harbors a substantial proportion of the ocean's unexplored biological and chemical diversity, while hydrothermal vent ecosystems expose resident organisms to unusual combinations of hydrostatic pressure, steep chemical gradients, reduced compounds, and elevated metal concentrations. This Review examines the deep-sea vent mussel Bathymodiolus azoricus, a dominant species at Mid-Atlantic Ridge hydrothermal fields, as a source of biological mechanisms and molecular systems with potential biomedical relevance. We integrate three areas that have largely developed separately in the literature: innate immunity and host-symbiont interactions, mussel-derived wet adhesion and byssal structural proteins, and shell biomineralization and repair. These published observations are complemented by targeted reanalyses of legacy and more recent B. azoricus transcriptomic resources, used here as supporting transcriptomic evidence for molecular families relevant to these themes rather than as standalone genome-scale transcriptomic studies. Particular attention is given to mussel foot proteins and byssal collagens as candidate templates for wet-tissue adhesives and structural biomaterials, and to shell-derived calcium carbonate as a potential precursor for calcium-phosphate-based materials. We further advance a specific, testable hypothesis-long-term exposure to the metal-rich hydrothermal vent environment may have influenced the metal-binding chemistry of B. azoricus adhesive and structural proteins, potentially generating functional properties distinct from those of shallow-water mytilids. This possibility is biologically plausible in light of established DOPA-metal coordination mechanisms in mussel adhesion, but no direct comparative measurements of Fe[3+]-binding affinity, metal-mediated cross-linking, or adhesive performance currently demonstrate such an advantage in B. azoricus. The species should therefore be regarded not as a proven source of superior vent-adapted biomaterials, but as a well-suited experimental system in which immunity, bioadhesion, biomineralization, and environmental adaptation converge to generate specific hypotheses for biomedical discovery. Comparative functional studies, protein-level validation of transcript-derived candidates, and improved molecular characterization of foot and mantle tissues will be required to test these possibilities.

Excessive melanin accumulation induced by UV exposure and hormonal changes poses significant challenges to skin health, necessitating safe and effective tyrosinase inhibitors. Pearl and nacre powder have long been utilized in traditional Chinese medicine for skin whitening. Our previous study identified a tyrosinase inhibitory peptide (Ala-His-Tyr-Tyr-Asp) from Pinctada martensii nacre in silico; however, chemical modification strategies for enhancing bioactive peptide efficacy remain underexplored. The present study investigated the structure-activity relationship of NP-TIP-1 (Tyrosinase Inhibitory Peptide of Nacre Powder-1) through three chemical modifications (C-terminal amidation, N-terminal acetylation, and N-terminal palmitoylation). C-terminal amidation significantly improved tyrosinase inhibitory potency, reducing the IC50 value from 2.012 ± 0.088 mM to 0.979 ± 0.028 mM, while retaining thermal stability and copper ion chelating capacity comparable to the native peptide. In B16F10 melanoma cells, NP-TIP-1-NH2 (C-terminally amidated NP-TIP-1) exhibited no cytotoxicity at concentrations up to 600 μM and concentration-dependently suppressed intracellular tyrosinase activity and melanin content. Mechanistic investigation revealed that NP-TIP-1-NH2 treatment downregulates the mRNA and protein expression of TYR and TRP-1 without affecting MITF (Microphthalmia-associated Transcription Factor) or TRP-2, suggesting a potential regulatory mechanism independent of MITF-mediated transcriptional control. Non-targeted metabolomics further identified nucleotide metabolism, purine metabolism, and glycine/serine/threonine metabolism as the most significantly perturbed pathways, with cytosine and GMP downregulated while guanosine and guanine were upregulated. This study establishes NP-TIP-1-NH2 as a promising candidate for multifunctional food preservatives and nutraceuticals, providing a strategic framework for C-terminal amidation as a structure-activity optimization approach for marine-derived anti-melanogenic peptides.