Search Results (223)

Reversible Solid Oxide Cells (rSOCs) are highly efficient energy conversion systems for power generation in fuel cell mode (SOFC) and energy storage in electrolysis mode (SOEC). These devices are typically manufactured through multi-step processing routes based on conventional functional ceramic fabrication techniques, such as tape-casting, extrusion, screen-printing and spraying. In this work, an alternative mold-casting approach is proposed for the fabrication of planar electrolyte-supported rSOCs. Electrolytes made of 8 mol% yttria-stabilized zirconia (YSZ) were prepared via an aqueous gel-casting process using agarose as the gelling agent. The casting molds were fabricated by 3D printing with polylactic acid (PLA) filament. Dense electrolytes with well-controlled geometries were successfully obtained. Complete cells were produced using porous Ni–YSZ as a fuel electrode and porous lanthanum strontium manganite–YSZ. The cells were microstructurally characterized, and their electrochemical performance was evaluated under both SOFC and SOEC operating conditions at 800–900 °C. At 900 °C, the cell achieved a peak power density of 220 mW cm⁻² in fuel cell mode and an injected current density of 340 mA cm⁻² at 1.3 V in electrolysis mode. Mid-term galvanostatic testing in SOFC mode at 850 °C for 400 h demonstrated good durability and structural stability of the fabricated cells. After the initial stabilization period, the cell exhibited a low degradation rate of 3 mV kh⁻¹. Full article

SrTiO₃/Nb₂O₅ composite materials with 1 and 10 wt.% Nb₂O₅ were prepared by a sol–gel route and characterized by XRD, Raman spectroscopy, SEM, BET, UV-Vis DRS, photoluminescence, and dielectric spectroscopy. The photocatalytic activity was evaluated via degradation of rhodamine B and tetracycline under UV and visible light. The addition of Nb₂O₅ resulted in a significant reduction in specific surface area (from 22.7 to 3.1 m²/g), a narrowing of the optical band gap (from 3.22 to 2.49 eV), and a decrease in photoluminescence intensity. Despite these changes, the photocatalytic performance decreased with increasing Nb₂O₅ content. For rhodamine B degradation, the UV rate constant fell from 0.0136 min⁻¹ for pristine SrTiO₃ to 0.0035 min⁻¹ for SrTiO₃/10% Nb₂O₅. The lower activity is mainly ascribed to the loss of active sites, surface carbonate formation, and enhanced non-radiative recombination at interface defects, which suppress charge transfer to the surface. The results demonstrate that careful control of the composite microstructure is essential for achieving efficient photocatalysis, even when heterojunction formation is thermodynamically favorable. Full article

The Lion Man sculpture (UNESCO World heritage), a left mammoth tusk and mammoth ivory fragments from the excavations in the Hohlenstein-Stadel cave, Lone valley, Swabian Alb, Germany, were non-invasively analysed by means of external ion beam analysis (IBA) at the microfocus beamline at the particle accelerator AGLAE. The Lion Man was reconstructed from about three hundred mammoth ivory fragments, while the tusk is a separate find, and the fragments are individual pieces that could not be placed in the Lion Man. A characteristic trace element fingerprint, based on zinc, bromine and strontium contents, was established according to previous IBA studies of Aurignacian-era mammoth ivory and allowed for a comparison of the mammoth ivory objects. The specific Hohlenstein-Stadel cave trace element fingerprint could be distinguished from that of other Aurignacian sites in Europe but closely resembles that of the contemporary ivories from the neighbouring Hohle Fels cave. Although this study highlights that the Lion Man sculpture is chemically inhomogeneous due to diagenetic alterations, the left tusk and individual ivory fragments are chemically very similar to the Lion Man. However, further analyses are required to relate them to the same animal. Secondary minerals such as black manganese oxide dendrites and iron-rich aluminosilicates could be identified on the Lion Man and the other ivory objects at the surface. While dendrites are a characteristic diagenetic feature of mammoth ivory, the origin of iron-rich aluminosilicates can be linked either to sediment traces or surface treatment and use wear of the sculpture. Iron-rich zones are identified on particular parts of the Lion Man, namely, at the snout and at the left forearm with decorative signs. The snout is also particularly enriched in carbon, whose origin still needs to be clarified. Full article

Global requirement of clean, cost-effective and sustainable energy has stimulated massive research and development in photocatalytic materials that have the potential to harvest solar based energy while mitigating the environmental issues. Among various materials, perovskite oxides have emerged as a promising energy resource. Owing to the structural versatility, optical and electrical properties, chemical inertness allows the use of material of multifunctional prospects. Currently Strontium titanate (SrTiO₃), a vital perovskite oxide having a band gap nearly ~3.2 eV, is showing significant function for photocatalytic water splitting, carbon dioxide conversion and degradation of organic pollutants. Though within the UV spectrum, its intrinsic photocatalytic behavior is limited to approaches such as graphene junctions, noble-metal support, and post-synthetic heat treatment seem to promote the adsorption within visible-light. Strontium titanate also demonstrates photo charge separation efficiency, and long-term catalytic durability. Moreover, modifications and hydrothermal synthesis have proven extremely efficient for nano-based engineering, control over crystal diameter, defects, and shape, which can result in magnificent composites that can be promising substitutes. Therefore, further research is imperative regarding these material application prospects. This comprehensive review provides insights into details on the potential of nanoengineering and composite approaches to reduce the inherent limitations of perovskite oxides, especially Strontium titanate, and enabling additional applications in next-generation photovoltaic and solar energy harvesting technologies. Full article

The photocatalytic activity of semiconductors can be tuned by changing their morphological or structural properties. However, a simpler and direct method is the introduction of a cocatalyst, for example V₂O₅ or V₂O₅/V₄O₉. In the present work, this was the cocatalyst added to SrTiO₃. The deposition method was directed in such a way that the cocatalyst did not cover the surface of the SrTiO₃ completely. This way, the photocatalytic process (phenol conversion) takes place at the surface of the main catalyst, while the lifetime of the generated charge carriers is increased through electron trapping via the presence of vanadium oxides. The V₂O₅/V₄O₉ cocatalyst influences the recombination processes of excited electrons in SrTiO₃ by modifying the near-surface defects of SrTiO₃, and it can efficiently capture electrons due to the formed heterojunction. The V₄O₉ content enables efficient electron transfer, as its structure can accommodate V⁴⁺ in addition to V⁵⁺. Therefore, a mixed-phase semiconductor is more suitable as a cocatalyst than a single-phase semiconductor. In this work, the photocatalytic activity of SrTiO₃ was investigated in the presence of V₂O₅ (0–20 wt.%). It was found that all the samples that contained the cocatalyst showed higher photocatalytic activity than the unmodified SrTiO₃. The sample containing 10 wt.% of cocatalyst performed ~5.4 times better than pristine SrTiO₃ (35.87 µmol_phenol/g_catalyst, vs. 7.74 µmol_phenol/g_catalyst). This sample also contains a relatively high amount of V₄O₉ compared to the other samples, in addition to V₂O₅, which may be the main reason for the enhanced photocatalytic performance. Full article

With the rapid development of flexible electronics technology, flexible wearable sensors based on Lanthanum Strontium Manganese Oxide (La_1-xSr_xMnO₃) have garnered extensive attention in recent years due to their excellent multi-functional integration, environmental stability and biocompatibility. This review systematically analyzes the preparation methods, process optimization strategies, multi-performance integration technologies, and the expansion of the application field of La_1-xSr_xMnO₃-based flexible sensors. Firstly, the basic characteristics and sensing mechanism of the La_1-xSr_xMnO₃ material were presented, including its temperature sensitivity, strain response characteristics, and magnetoresistance effect. Secondly, the fabrication process of flexible sensors was elaborately discussed, with a focus on analyzing crucial technologies, such as laser induction and transfer printing technology. Subsequently, the strategies for regulating the electrical, thermal, and mechanical properties of materials through element doping, along with the multimodal sensing integration and signal decoupling methods, were expounded. Furthermore, the actual performance of this type of sensor in fields such as health monitoring, human–computer interaction, and extreme environment applications was summarized. Finally, the challenges and future development directions of La_1-xSr_xMnO₃-based flexible sensors are outlined, providing theoretical references for the design and optimization of next-generation flexible electronic devices. Full article

Japanese flounder (Paralichthys olivaceus) is an economically important species in China’s marine fishery industry. However, due to long-term intensive fishing, its wild population has declined sharply. Artificial stock enhancement has become a core measure for restoring its resources. This study aimed to investigate the effects of different immersion durations and concentrations of SrCl₂ solution (10, 20, 40, 80 mg/L) on strontium (Sr) deposition in the otoliths of P. olivaceus, and to systematically evaluate the impacts of Sr marking on the fish’s antioxidant capacity and digestive enzyme activity. The results showed that the otolith Sr/Ca ratio was positively correlated with marking concentration and duration; the optimal parameters were 40 mg/L for 4 days, with the Sr/Ca ratio returning to baseline after 30 days post-marking, and a 100% marking success rate. There were no significant differences in body length, body weight, or condition factor between the experimental groups and the control group (p > 0.05), but mortality was significantly increased in the 80 mg/L group. Digestive enzymes exhibited a dose-dependent response to Sr exposure, characterized by activation at low concentrations and inhibition at high concentrations; lipase was the most sensitive, with an inhibition threshold of 10 mg/L. Sr marking within the range of 20–40 mg/L for 4–8 days significantly activated the activity of T-AOC, CAT, GPx, and SOD (p < 0.05) and reduced MDA content, indicating that the antioxidant system was activated without causing persistent oxidative damage. In conclusion, Sr marking is a safe and efficient method for otolith marking in Paralichthys olivaceus. The recommended protocol is immersion in a 40 mg/L SrCl₂ solution for 4 days, followed by a 30-day recovery period in clean seawater before being used for stock enhancement evaluation. This study provides a scientific basis and technical support for assessing the effectiveness of stock enhancement in P. olivaceus. Full article

Chitosan–hydroxyapatite (CS–HA) composite coatings offer a multifunctional surface modification to improve titanium implant performance, combining hydroxyapatite’s osteoconductivity with chitosan’s biocompatibility and antimicrobial properties. This review examines recent in vitro and in vivo studies, noting consistent enhancements in osteoblast adhesion, alkaline phosphatase activity, apatite formation, and bone–implant contact. Incorporation of silver, strontium, or graphene oxide can further boost antibacterial and osteogenic effects. However, variability in coating preparation, substrate treatment, and testing protocols limits reproducibility and clinical extrapolation. Standardised methodologies and extended in vivo validation are essential to advance CS–HA coatings toward reliable dental and orthopaedic applications. Full article

Strontium (Sr) is an essential trace element that plays a critical role in bone health, calcium absorption, cardiovascular function, and nerve function. In this experiment, fresh-cut peaches were treated with different concentrations of strontium chloride (SrCl₂) to study the effects of SrCl₂ on the antioxidant system, endogenous nitric oxide (NO) metabolism, and endogenous hydrogen sulfide (H₂S) metabolism, aiming to investigate the regulatory mechanism of Sr on postharvest quality of horticultural products. The results showed that, compared with the control, 320 μM SrCl₂ significantly suppressed the respiration rate by 15.10% and delayed the respiratory peak by 2 days. Meanwhile, SrCl₂ treatment effectively inhibited the rise in electrolyte leakage (EL), color difference, and weight loss, and delayed the decline in fruit firmness. In addition, SrCl₂ treatment significantly up-regulated the gene expression levels and enzyme activities of the antioxidant system, the AsA-GSH cycle, NO, and H₂S metabolism, which reduced the loss of antioxidants, enhanced the ability of fruits to scavenge hydrogen peroxide (H₂O₂), hydroxyl radical (˙OH), and superoxide anion (O₂⁻˙), and lowered the malondialdehyde (MDA) content. It suggests that SrCl₂ treatment has a positive effect on maintaining the postharvest quality of fresh-cut peaches, which appears to be associated with increased endogenous production of NO and H₂S, thereby enhancing antioxidant system activity. Full article

Titanium implants are widely used in orthopedic and dental fields but often face challenges such as insufficient osseointegration and peri-implant inflammation. While Strontium (Sr) possesses potent bioactive properties, achieving its controlled delivery at the implant-tissue interface remains technically challenging. To address this, we engineered a multidimensional composite coating by constructing a micro/nano-porous TiO₂ substrate via micro-arc oxidation (MAO), followed by polydopamine (PDA)-assisted Sr immobilization. This integrated architecture significantly enhanced surface hydrophilicity and facilitated high-content Sr loading with sustained release kinetics. Biological evaluations demonstrated that the PDA-mediated interface promoted superior initial adhesion and spreading of bone marrow mesenchymal stem cells (BMSCs), synergizing with released Sr²⁺ to markedly upregulate core osteogenic markers (Runx2, ALP). Crucially, the functionalized surface actively optimized the immune microenvironment by inducing M1-to-M2 macrophage polarization and comprehensively suppressing RANKL-induced osteoclastogenesis via the downregulation of TRAP and DC-STAMP. By integrating these pro-osteogenic, anti-inflammatory, and anti-resorptive capabilities, this tri-functional system effectively rebalances the bone remodeling microenvironment. Consequently, it provides a robust, universally applicable strategy for enhancing the therapeutic efficacy of next-generation orthopedic and dental implants. Full article

The thermal decomposition (pyrolysis) of polypropylene has been investigated as a viable method for polymer waste recycling and the production of hydrogen-rich fuel. This study examined the effects of atmosphere, temperature, and catalytic systems based on iron oxide and strontium titanate, with a focus on gas-phase composition and reaction dynamics. A reactor geometry conducive to in-bed reforming was utilized, leading to a purer gas output compared to commonly reported results, making it suitable for solid oxide fuel cell (SOFC) applications. The hydrogen concentration was enhanced with increasing temperature, primarily due to the intensified reforming of methane and higher hydrocarbons. However, only marginal improvements were observed between 700 °C and 800 °C, which limits the benefits of higher energy input. The introduction of small amounts of water vapor (approximately 3% relative humidity) resulted in a reduction in solid residue formation by approximately 50% and a slight increase in hydrogen yield. Conversely, CO₂ atmospheres suppressed hydrogen production and increased residual solids but allowed for better control over reaction dynamics. The combined strontium titanate iron oxide catalyst (S-STO@Fe_xO_γ) demonstrated high efficacy, reducing solid residues to nearly zero and producing gas mixtures containing up to 45% hydrogen. This indicates significant potential for application and further development. These findings underscore the feasibility of in-bed reforming in polypropylene pyrolysis as a waste-to-energy strategy for hydrogen-rich fuel production, warranting further optimization and investigation for SOFC integration. Full article

Mesoporous bioactive glass nanoparticles (MBGNs) are promising for bone tissue engineering; however, surgical site infection and oxidative stress often compromise regeneration. To address this, MBGNs co-doped with cerium (Ce), zinc (Zn), and strontium (Sr) were synthesized using a microemulsion-assisted sol-gel route (xCe-yZn-Sr-MBGNs; x = 0, 1, 2; y = 0, 0.5, 1). The resulting spherical nanoparticles (150–200 nm) exhibited a mesoporous structure with a specific surface area of (~340–425 m²/g), sustained ion release, and apatite formation in simulated body fluid. In vitro evaluations with MC3T3-E1 pre-osteoblasts demonstrated dose-dependent cytocompatibility, specifically in the co-doped formulations; however, higher Ce concentrations (2Ce-yZn-Sr-MBGNs) reduced viability following prolonged exposure. Crucially, the 1Ce-1Zn-Sr-MBGNs significantly enhanced osteogenic differentiation, as evidenced by a two-fold increase in osteogenic marker gene expression and a ~45% increase in calcium mineral deposition compared to undoped MBGNs within 14 days. Moreover, these particles accelerated cell migration, achieving ~70% scratch-wound closure within 24 h. Furthermore, 1Ce-1Zn-Sr-MBGNs displayed strong radical scavenging capacity and potent antibacterial activity against S. aureus and P. aeruginosa. These findings indicated that 1Ce-1Zn-Sr-MBGNs exhibited multiple therapeutic effects, including antibacterial, radical-scavenging, and osteogenic effects. By optimizing dopant ratios, these multifunctional nanomaterials emerge as promising candidates for next-generation bone grafts or implant coatings. Within the scope of this study, they demonstrated the capacity to simultaneously address three critical challenges in bone healing: controlling infection, mitigating oxidative stress, and promoting mineralized tissue formation. While these in vitro results provide a robust foundation, further in vivo validation is warranted to confirm their efficacy within complex physiological environments. Full article

Biofilm-associated infections remain a major barrier to wound healing, implant integration, and chronic infection management. Rare-earth oxides (REOs) have emerged as promising antibiofilm materials, though their mechanisms, limitations, and translational potential are still being defined. Cerium oxide (CeO₂) serves as the benchmark due to its redox adaptability, oxygen-vacancy-driven catalytic activity, and host compatibility. In contrast, non-ceria REOs show antibiofilm effects under more restricted conditions, often requiring surface functionalization, composite architectures, or hybrid organic–inorganic interfaces—such as polyphenol coatings or hydroxyapatite-based composites—to achieve comparable activity. Across systems, biofilm control arises not from bactericidal potency but from matrix-level mechanisms including extracellular polymeric substance (EPS) destabilization, extracellular DNA (eDNA) sequestration, redox modulation, and quorum-sensing interference. Preclinical and near-clinical evidence, particularly in chronic wound models, supports the translational relevance of these mechanisms, though the evidence base remains preliminary. This review synthesizes mechanistic data across cerium-, samarium-, lanthanum-, and strontium-based systems to establish a unified framework for REO-mediated biofilm disruption. REOs are positioned as biofilm-modulating platforms that complement antibiotics, enhance healing, and improve outcomes. Design rules emphasize controlled redox activity, targeted coordination chemistry, functional surface engineering, and host-compatible performance, alongside regulatory and manufacturing guidance for future development. Full article

Organic dye pollution in industrial wastewater poses a serious environmental challenge, with methylene blue (MB) serving as a typical persistent pollutant due to its stable chemical structure, recalcitrance to degradation, and eco-toxicity. Conventional physical, chemical, and biological treatment methods suffer from limitations such as insufficient efficiency, high cost, or the tendency to generate secondary pollution. Based on green and sustainable photocatalysis technology, this study designed and prepared a NiO/SrTiO₃ p-n heterojunction photocatalysts, aiming to broaden the light-response range and enhance charge-carrier separation efficiency. The optimal sample (NiO (10%)/SrTiO₃) achieved complete photocatalytic degradation of MB within 9 min, with an apparent rate constant 34.6 times that of pure SrTiO₃. It also showed good cyclic stability. Trapping experiments confirmed that •OH and •O₂⁻ were the key active species in the degradation process. Combined with band structure and PL analyses, an S-scheme charge-transfer mechanism was proposed, clarifying the critical role of the built-in electric field at the heterojunction interface in promoting carrier separation while maintaining high redox capability. This work not only provides a new pathway for developing efficient and stable SrTiO₃-based photocatalysts but also offers theoretical and experimental support for the practical application of p-n heterojunction photocatalysts in environmental pollution control. Full article

Background/Objectives: Ash made from juniper trees and added to cornmeal-based dishes may have provided calcium (Ca) to traditional Indigenous diets. Few studies have quantified the mineral content of juniper ash, including its Ca content. The objective of this study was to determine whether juniper ash could serve as a safe source of non-dairy Ca in an intervention study. Methods: Branches from two varieties of Juniper (Rocky Mountain Juniper, or Juniperus scopulorum and Eastern Red Cedar, or Juniperus virginiana) were harvested and burned to ash in a laboratory setting. Juniper ash from the southwestern U.S. available for retail purchase was used for comparison. All samples were tested for content of 10 nutritive elements (Ca, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, selenium, and zinc) and 20 potentially toxic elements (silver, aluminum, arsenic, barium, beryllium, cadmium, cobalt, chromium, mercury, lithium, molybdenum, nickel, lead, antimony, tin, strontium, thallium, uranium, and vanadium) as well as n = 576 pesticide residues. Results: All samples contained both nutritive and potentially toxic elements. Each teaspoon of ash contained an average of 445 ± 141 mg Ca. However, the samples also contained lead in amounts ranging from 1.09 ppm to 15 ppm. Conclusions: Information on the nutritive and potentially toxic elemental content of juniper ash and how it may interact within a food matrix is insufficient to determine its safety as a Ca source. Further investigation is needed on the bioavailability of calcium oxide and its interaction with other dietary components to clarify the potential role of juniper ash in contemporary food patterns. Full article