Strontium isotopes in the atmosphere, geosphere and hydrosphere: Developing a systematic "fingerprinting" framework of rocks and water in sedimentary basins in eastern Australia.

Understanding the connection between aquifers, aquitards, and groundwater-dependant ecosystems remains a key challenge when developing a conceptual hydrogeological model. The aim of this study was to develop a systematic strontium isotope (87Sr/86Sr) fingerprinting framework of rocks and water within the sedimentary Surat and Clarence-Moreton basins (SCM basins) in eastern Australia - an area of extensive coal seam gas development and high potential for aquifer and groundwater-surface water connectivity. To do this, new groundwater samples (n = 298) were collected, analyzed and integrated with published data (n = 154) from the basins' major sedimentary, volcanic and alluvial aquifers, including the major coal seam gas target, the Walloon Coal Measures. Samples were also analyzed from rainfall (n = 2) and surface water (n = 40). In addition, rock core samples (n = 39) from exploration and stratigraphic wells were analyzed to determine the range of Sr isotope composition from host rocks. The analyses of cores demonstrate a distinct and systematic contrast in 87Sr/86Sr between different hydrogeological units. The analyses confirm that all major hydrogeological units have a narrow range with unique 87Sr/86Sr population characteristics that are useful for guiding conceptual model development. Comparison with selected hydrochemical and groundwater age tracers (14C and 36Cl) suggests only limited changes of 87Sr/86Sr from recharge beds to the deeper parts of the basins or with a decrease in natural 14C and 36Cl tracer content along flow paths. Stream sampling during baseflow conditions confirms that 87Sr/86Sr in surface waters are similar to those of the underlying bedrock formations. We demonstrated that 87Sr/86Sr analyses of rocks and water provide a powerful hydrostratigraphic and chemostratigraphic fingerprinting framework in the SCM basins, enabling reliable assessments of plausible aquifer and groundwater-surface water interconnectivity pathways. Applied in other complex multi-aquifer sedimentary basins in Australia, and globally, a similar approach can help to constrain conceptual hydrogeological models and facilitate improved water resource management.

Radionuclide Solid:liquid partitioning in an aged, reducing-grout wasteform recovered from a disposal facility.

The Saltstone Disposal Facility on the Savannah River Site in South Carolina disposes of Low-Level Waste in a reducing-grout waste form. Reducing grout is presently being evaluated as a subsurface disposal waste form at several other locations in the United States, as well as in Europe and Asia. The objective of this study was to collect core samples directly from the Saltstone Disposal Facility and measure desorption distribution coefficients (Kd; radionuclide concentration ratio of saltstone:liquid; (Bq/kg)/Bq/L)) and desorption apparent solubility values (ksp; radionuclide aqueous concentration (moles/L)). An important attribute of this study was that these tests were conducted with actual aged, grout waste form materials, not small-volume simulants prepared in a laboratory. The reducing grout is comprised of blast furnace slag, Class F fly ash, ordinary portland cement, and a radioactive salt waste solution generated during nuclear processing. The grout sample used in this study underwent hydrolyzation in the disposal facility for 30 months prior to measuring radionuclide leaching. Leaching experiments were conducted either in an inert (no oxygen) atmosphere to simulate conditions within the saltstone monolith prior to aging (becoming oxidized) or they were exposed to atmosphere conditions to simulate conditions of an aged saltstone. Importantly, these experiments were designed not to be diffusion limited, that is, the saltstone was ground finely and the suspensions were under constant agitation during the equilibration period. Under oxidized conditions, measured Tc Kd values were 10 mL/g, which was appreciably greater than the historical best-estimate value of 0.8 mL/g. This difference is likely the result of a fraction of the Tc remaining in the less soluble Tc(IV) form, even after extensive oxidation during the experiment. Under oxidized and reducing conditions, the measured Ba and Sr (both divalent alkaline earth metals) Kd value were more than an order of magnitude greater than historical best-estimate values of 100 mL/g. The unexpectedly high Ba and Sr Kd values were attributed to these radionuclides having sufficient time to age (form strong bonds) in the sulfur-rich saltstone sample. Apparent ksp values under reducing conditions were 10-9 mol/L Tc and 10-13 mol/L Pu, consistent with values measured with surrogate materials. Measured apparent Ba, Sr, and Th ksp values were significantly greater than historical best-estimates. The implications of the generally greater Kd values and lower ksp values in these measurements is that these cementitious waste forms have greater radionuclide retention than was previously estimated based on laboratory studies using surrogate materials. This work represents the first leaching study performed with an actual aged, reducing-grout sample and as such provides an important comparison to studies conducted with surrogate materials, and provides high pedigree data for other programs around the world evaluating reducing grouts as a wasteform for subsurface nuclear waste disposal.

Response Properties of Electrorheological Composite Hydrophilic Elastomers Based on Different Morphologies of Magnesium-Doped Strontium Titanate.

As smart materials, electrorheological elastomers (EREs) formed by pre-treating active electrorheological particles are attracting more and more attention. In this work, four Mg-doped strontium titanate (Mg-STO) particles with spherical, dendritic, flake-like, and pinecone-like morphologies were obtained via hydrothermal and low-temperature co-precipitation. XRD, SEM, Raman, and FT-IR were used to characterize these products. The results showed that Mg-STOs are about 1.5-2.0 µm in size, and their phase structures are dominated by cubic crystals. These Mg-STOs were dispersed in a hydrogel composite elastic medium. Then, Mg-STO/glycerol/gelatin electrorheological composite hydrophilic elastomers were obtained with or without an electric field. The electric field response properties of Mg-doped strontium titanate composite elastomers were investigated. We concluded that dendritic Mg-STO composite elastomers are high-performance EREs, and the maximum value of their energy storage was 8.70 MPa. The significant electrorheological performance of these products is helpful for their applications in vibration control, force transducers, smart structures, dampers, and other fields.

Mesoporous Silicon with Strontium-Powered Poly(Lactic-Co-Glycolic acid)/Gelatin-Based Dressings Facilitate Skin Tissue Repair.

Purpose: Functional inorganic nanomaterials (NMs) are widely exploited as bioactive materials and drug depots. The lack of a stable form of application of NMs at the site of skin injury, may impede the removal of the debridement, elevate pH, induce tissue toxicity, and limit their use in skin repair. This necessitates the advent of innovative wound dressings that overcome the above limitations. The overarching objective of this study was to exploit strontium-doped mesoporous silicon particles (PSiSr) to impart multifunctionality to poly(lactic-co-glycolic acid)/gelatin (PG)-based fibrous dressings (PG@PSiSr) for excisional wound management. Methods: Mesoporous silicon particles (PSi) and PSiSr were synthesized using a chemo-synthetic approach. Both PSi and PSiSr were incorporated into PG fibers using electrospinning. A series of structure, morphology, pore size distribution, and cumulative pH studies on the PG@PSi and PG@PSiSr membranes were performed. Cytocompatibility, hemocompatibility, transwell migration, scratch wound healing, and delineated angiogenic properties of these composite dressings were tested in vitro. The biocompatibility of composite dressings in vivo was assessed by a subcutaneous implantation model of rats, while their potential for wound healing was discerned by implantation in a full-thickness excisional defect model of rats. Results: The PG@PSiSr membranes can afford the sustained release of silicon ions (Si4+) and strontium ions (Sr2+) for up to 192 h as well as remarkably promote human umbilical vein endothelial cells (HUVECs) and NIH-3T3 fibroblasts migration. The PG@PSiSr membranes also showed better cytocompatibility, hemocompatibility, and significant formation of tubule-like networks of HUVECs in vitro. Moreover, PG@PSiSr membranes also facilitated the infiltration of host cells and promoted the deposition of collagen while reducing the accumulation of inflammatory cells in a subcutaneous implantation model in rats as assessed for up to day 14. Further evaluation of membranes transplanted in a full-thickness excisional wound model in rats showed rapid wound closure (PG@SiSr vs control, 96.1% vs 71.7%), re-epithelialization, and less inflammatory response alongside skin appendages formation (eg, blood vessels, glands, hair follicles, etc.). Conclusion: To sum up, we successfully fabricated PSiSr particles and prepared PG@PSiSr dressings using electrospinning. The PSiSr-mediated release of therapeutic ions, such as Si4+ and Sr2+, may improve the functionality of PLGA/Gel dressings for an effective wound repair, which may also have implications for the other soft tissue repair disciplines.

Facile fabrication of linezolid/strontium coated hydroxyapatite/graphene oxide nanocomposite for osteoporotic bone defect.

Hydroxyapatite (HAp) coatings currently have limited therapeutic applications because they lack anti-infection, osteoinductivity, and poor mechanical characteristics. On the titanium substrate, electrochemical deposition (ECD) was used to construct the strontium (Sr)-featuring hydroxyapatite (HAp)/graphene oxides (GO)/linezolid (LZ) nanomaterial coated with antibacterial and drug delivery properties. The newly fabricated nanomaterials were confirmed by X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis and morphological features were examined by scanning electron microscope (SEM) analysis. The results reveal multiple nucleation sites for SrHAp/GO/LZ composite coatings due to oxygen-comprising moieties on the 2D surface of GO. It was shown to be favorable for osteoblast proliferation and differentiation. The elastic modulus and hardness of LZ nanocomposite with SrHAp/GO/LZ coatings were increased by 67 % and 121 %, respectively. An initial 5 h burst of LZ release from the SrHAp/GO/LZ coating was followed by 14 h of gradual release, owing to LZ's physical and chemical adsorption. The SrHAp/GO/LZ coating effectively inhibited both S. epidermidis and S. aureus, and the inhibition lasted for three days, as demonstrated by the inhibition zone and colony count assays. When MG-63 cells are coated with SrHAp/GO/LZ composite coating, their adhesion, proliferation, and differentiation greatly improve when coated with pure titanium. A novel surface engineering nanomaterial for treating and preventing osteoporotic bone defects, SrHAp/GO/LZ, was shown to have high mechanical characteristics, superior antibacterial abilities, and osteoinductivity.

Ti3C2Tx MXene-Decorated 3D-Printed Ceramic Scaffolds for Enhancing Osteogenesis by Spatiotemporally Orchestrating Inflammatory and Bone Repair Responses.

Inflammatory responses play a central role in coordinating biomaterial-mediated tissue regeneration. However, precise modulation of dynamic variations in microenvironmental inflammation post-implantation remains challenging. In this study, the traditional ß-tricalcium phosphate-based scaffold is remodeled via ultrathin MXene-Ti3C2 decoration and Zn2+/Sr2+ ion-substitution, endowing the scaffold with excellent reactive oxygen species-scavenging ability, near-infrared responsivity, and enhanced mechanical properties. The induction of mild hyperthermia around the implant via periodic near-infrared irradiation facilitates spatiotemporal regulation of inflammatory cytokines secreted by a spectrum of macrophage phenotypes. The process initially amplifies the pro-inflammatory response, then accelerates M1-to-M2 macrophage polarization transition, yielding a satisfactory pattern of osteo-immunomodulation during the natural bone healing process. Later, sustained release of Zn2+/Sr2+ ions with gradual degradation of the 3D scaffold maintains the favorable reparative M2-dominated immunological microenvironment that supports new bone mineralization. Precise temporal immunoregulation of the bone healing process by the intelligent 3D scaffold enhances bone regeneration in a rat cranial defect model. This strategy paves the way for the application of ß-tricalcium phosphate-based materials to guide the dynamic inflammatory and bone tissue responses toward a favorable outcome, making clinical treatment more predictable and durable. The findings also demonstrate that near-infrared irradiation-derived mild hyperthermia is a promising method of immunomodulation.

Biphasic bone substitutes coated with PLGA incorporating therapeutic ions Sr2+ and Mg2+: cytotoxicity cascade and in vivo response of immune and bone regeneration.

The incorporation of bioactive ions into biomaterials has gained significant attention as a strategy to enhance bone tissue regeneration on the molecular level. However, little knowledge exists about the effects of the addition of these ions on the immune response and especially on the most important cellular regulators, the macrophages. Thus, this study aimed to investigate the in vitro cytocompatibility and in vivo regulation of bone remodeling and material-related immune responses of a biphasic bone substitute (BBS) coated with metal ions (Sr2+/Mg2+) and PLGA, using the pure BBS as control group. Initially, two cytocompatible modified material variants were identified according to the in vitro results obtained following the DIN EN ISO 10993-5 protocol. The surface structure and ion release of both materials were characterized using SEM-EDX and ICP-OES. The materials were then implanted into Wistar rats for 10, 30, and 90 days using a cranial defect model. Histopathological and histomorphometrical analyses were applied to evaluate material degradation, bone regeneration, osteoconductivity, and immune response. The findings revealed that in all study groups comparable new bone formation were found. However, during the early implantation period, the BBS_Sr2+ group exhibited significantly faster regeneration compared to the other two groups. Additionally, all materials induced comparable tissue and immune responses involving high numbers of both pro-inflammatory macrophages and multinucleated giant cells (MNGCs). In conclusion, this study delved into the repercussions of therapeutic ion doping on bone regeneration patterns and inflammatory responses, offering insights for the advancement of a new generation of biphasic calcium phosphate materials with potential clinical applicability.

Biological and Physicochemical Analysis of Sr-Doped Hydroxyapatite/Chitosan Composite Layers.

In this work results are presented on the evaluation of HAp, HApSr, HAp_CS, and HApSr_CS layers deposited on Ti substrates regarding L929 cell viability and cytotoxicity as well as antimicrobial activity against Staphylococcus aureus, in connection with their physicochemical properties. The HAp and HApSr layers generated by radio-frequency magnetron sputtering technique were further covered with chitosan by a matrix-assisted pulsed laser evaporation technique. During the plasma depositions, the Ti substrates were heated externally by a home-made oven above 100 °C. The HApSr_CS layers generated on the unpolished Ti substrates at 100 °C and 400 °C showed the highest biocompatibility properties and antimicrobial activity against Staphylococcus aureus. The morphology of the layer surfaces, revealed by scanning electron microscopy, is dependent on substrate temperature and substrate surface roughness. The optically polished surfaces of Ti substrates revealed grain-like and microchannel structure morphologies of the layers deposited at 25 °C substrate temperature and 400 °C, respectively. Chitosan has no major influence on HAp and HApSr layer surface morphologies. X-ray photoelectron spectroscopy indicated the presence of Ca 2p3/2 peak characteristic of the HAp structure even in the case of the HApSr_CS samples generated at a 400 °C substrate temperature. Fourier transform infrared spectroscopy investigations showed shifts in the wavenumber positions of the P-O absorption bands as a function of Sr or chitosan presence in the HAp layers generated at 25, 100, and 400 °C substrate temperatures.

3D-Bioprinted Gelatin Methacryloyl-Strontium-Doped Hydroxyapatite Composite Hydrogels Scaffolds for Bone Tissue Regeneration.

New gelatin methacryloyl (GelMA)-strontium-doped nanosize hydroxyapatite (SrHA) composite hydrogel scaffolds were developed using UV photo-crosslinking and 3D printing for bone tissue regeneration, with the controlled delivery capacity of strontium (Sr). While Sr is an effective anti-osteoporotic agent with both anti-resorptive and anabolic properties, it has several important side effects when systemic administration is applied. Multi-layer composite scaffolds for bone tissue regeneration were developed based on the digital light processing (DLP) 3D printing technique through the photopolymerization of GelMA. The chemical, morphological, and biocompatibility properties of these scaffolds were investigated. The composite gels were shown to be suitable for 3D printing. In vitro cell culture showed that osteoblasts can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA-SrHA hydrogel has good cell viability and biocompatibility. The GelMA-SrHA composites are promising 3D-printed scaffolds for bone repair.

A functional mineralized collagen hydrogel to promote angiogenic and osteogenic for osseointegration of 3D-printed titanium alloy microporous scaffolds.

Bone defects, resulting from trauma, inflammation, tumors, and various other factors, affect both health and quality of life. Although autologous bone transplantation is the gold-standard treatment for bone defects, it has disadvantages such as donor site limitations, prolonged surgical durations, and potential complications, necessitating the development of alternative bone tissue engineering materials. In this study, we used 3D printing technology to fabricate porous titanium implants characterized by superior biocompatibility and mechanical properties. Sodium alginate (SA) and strontium ions (Sr2+) were integrated into mineralized collagen matrices (MCs) to develop strontium-functionalized alginate-mineralized collagen hydrogels (SAMs) with high mechanical strength and sustained metal ion release ability. SAMs were seamlessly incorporated into the porous structures of 3D-printed titanium scaffolds, establishing a novel organic-inorganic bioactive interface. This composite system exhibited high biocompatibility in vitro and increased the expression of genes important for osteogenic differentiation and angiogenesis. In a rabbit model of femoral defect, the titanium implants effectively promoted bone and vascular regeneration on their surface, highlighting their potential in facilitating bone-implant integration.

ECM-Mimicking Strontium-Doped Nanofibrous Microspheres for Periodontal Tissue Regeneration in Osteoporosis.

Regenerating periodontal defects in osteoporosis patients presents a significant clinical challenge. Unlike the relatively straightforward regeneration of homogeneous bone tissue, periodontal regeneration requires the intricate reconstruction of the cementum-periodontal ligament-alveolar bone interface. Strontium (Sr)-doped biomaterials have been extensively utilized in bone tissue engineering due to their remarkable pro-osteogenic attributes. However, their application in periodontal tissue regeneration has been scarcely explored. In this study, we synthesized an innovative injectable Sr-BGN/GNM scaffold by integrating Sr-doped bioactive glass nanospheres (Sr-BGNs) into the nanofiber architecture of gelatin nanofiber microspheres (GNMs). This design, mimicking the natural bone extracellular matrix (ECM), enhanced the scaffold's mechanical properties and effectively controlled the sustained release of Sr ions (Sr2+), thereby promoting the proliferation, osteogenic differentiation, and ECM secretion of PDLSCs and BMSCs, as well as enhancing vascularization in endothelial cells. In vivo experiments further indicated that the Sr-BGNs/GNMs significantly promoted osteogenesis and angiogenesis. Moreover, the scaffold's tunable degradation kinetics optimized the prolonged release and pro-regenerative effects of Sr2+ in vivo, matching the pace of periodontal regeneration and thereby facilitating the regeneration of functional periodontal tissues under osteoporotic conditions. Therefore, Sr-BGNs/GNMs emerge as a promising candidate for advancing periodontal regeneration strategies.

Antimicrobial Potential of Strontium-Functionalized Titanium Against Bacteria Associated With Peri-Implantitis.

OBJECTIVES: To explore the antimicrobial potential of strontium (Sr)-functionalized wafers against multiple bacteria associated with per-implant infections, in both mono- and multispecies biofilms. MATERIALS AND METHODS: The bactericidal and bacteriostatic effect of silicon wafers functionalized with a strontium titanium oxygen coating (Sr-Ti-O) or covered only with Ti (controls) against several bacteria, either grown as a mono-species or multispecies biofilms, was assessed using a bacterial viability assay and a plate counting method. Mono-species biofilms were assessed after 2 and 24 h, while the antimicrobial effect on multispecies biofilms was assessed at Days 1, 3, and 6. The impact of Sr functionalization on the total percentage of Porphyromonas gingivalis in the multispecies biofilm, using qPCR, and gingipain activity was also assessed. RESULTS: Sr-functionalized wafers, compared to controls, were associated with statistically significant less viable cells in both mono- and multispecies tests. The number of colony forming units (CFUs) within the biofilm was significantly less in Sr-functionalized wafers, compared to control wafers, for Staphylococcus aureus at all time points of evaluation and for Escherichia coli at Day 1. Gingipain activity was less in Sr-functionalized wafers, compared to control wafers, and the qPCR showed that P. gingivalis remained below detection levels at Sr-functionalized wafers, while it consisted of 15% of the total biofilm on control wafers at Day 6. CONCLUSION: Sr functionalization displayed promising antimicrobial potential, possessing bactericidal and bacteriostatic ability against bacteria associated with peri-implantitis grown either as mono-species or mixed in a multispecies consortium with several common oral microorganisms.

Integrating otolith and genetic tools to reveal intraspecific biodiversity in a highly impacted salmon population.

Intraspecific biodiversity is vital for species persistence in an increasingly volatile world. By embracing methods that integrate information at different spatiotemporal scales, we can directly monitor and reconstruct changes in intraspecific biodiversity. Here we combined genetics and otolith biochronologies to describe the genotypic and phenotypic diversity of Chinook salmon (Oncorhynchus tshawytscha) in the Yuba River, California, comparing cohorts that experienced a range of hydroclimatic conditions. Yuba River salmon have been heavily impacted by habitat loss and degradation, and large influxes of unmarked hatchery fish each year have led to concern about introgression and uncertainty around the viability of its wild populations, particularly the rarer spring-run salmon. Otolith strontium isotopes showed that Yuba River origin fish represented, on average, 42% (range 7%-73%) of spawners across six return years (2009-2011, 2018-2020), with large interannual variability. The remainder of adult Chinook salmon in the river were primarily strays from the nearby Feather River hatchery, and since 2018 from the Mokelumne River hatchery. Among the Yuba-origin spawners, on average, 30% (range 14%-50%) exhibited the spring-run genotype. The Yuba-origin fish also displayed a variety of outmigration phenotypes that differed in the timing and size at which they left the Yuba river. Early-migrating fry dominated the returns (mean 59%, range 33%-89%), and their contribution rates were negatively correlated with freshwater flows. It is unlikely that fry survival rates are elevated during droughts, suggesting that this trend reflects disproportionately low survival of larger later migrating parr, smolts, and yearlings along the migratory corridor in drier years. Otolith daily increments indicated generally faster growth rates in non-natal habitats, emphasizing the importance of continuing upstream restoration efforts to improve in-river growing conditions. Together, these findings show that, despite a long history of habitat degradation and hatchery introgression, the Yuba River maintains intraspecific biodiversity that should be taken into account in future management, restoration, and reintroduction plans. The finding that genotypic spring-run are reproducing, surviving, and returning to the Yuba River every year suggests that re-establishment of an independent population is possible, although hatchery-wild interactions would need to be carefully considered. Integrating methods is critical to monitor changes in key genetic, physiological, and behavioral traits to assess population viability and resilience.

Concentration-dependent luminescence characterization of terbium-doped strontium aluminate nanophosphors.

The present investigation describes the synthesis of luminescent terbium-doped strontium aluminate nanoparticles emitting bright green light, which were synthesized through a solid-state reaction method assisted by microwave radiation. Various samples containing different concentrations of Tb were synthesized, and an analysis of their structural and morphological features was conducted using powder x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The band gaps of the samples were determined utilizing the Kubelka-Munk method. The quenching mechanism observed was identified to be due to dipole-dipole interaction using the Dexter theory. The optimized sample with a terbium concentration of 4 at.% has a luminescence lifetime of 1.05 ms with 20.62% quantum efficiency. The results of this study indicate that the terbium-doped strontium aluminate fluorescent nanoparticles exhibit promising potential for a wide range of applications, including bioimaging, sensing and solid-state lighting.

Differences and implications of strontium distribution coefficient on various granite compositional materials.

The distribution coefficient (Kd) of radionuclides is a crucial parameter in assessing the safety of high-level radioactive waste (HLW) geological repository. It is determined in the laboratory through batch and column experiments. However, differences in obtained Kd values from distinct experiments have not been thoroughly assessed and compared. This study evaluated strontium (Sr) sorption on different granite materials using static batch and dynamic experiments (column and core-flooding experiments). The results from batch sorption experiments showed higher Sr sorption on granite under acidic and strongly alkaline conditions, low solid-liquid ratios, and low ionic strength. In column experiments, a two-site sorption model was used to simulate Sr transport in crushed granite and mixed pure minerals. The sorption of Sr on crushed granite exhibited a higher affinity than that of mixed pure minerals. The dual-porosity transport model was employed to investigate Sr transport behavior in fractured granite in the core-flooding experiment. Kd obtained from batch sorption experiments are four to twenty times higher than those from column experiments, and two to three orders of magnitude higher than that from a core-flooding experiment. The results of this study provide valuable insights into safety assessment for the HLW geological repository.

Assessing Movements between Freshwater and Saltwater by Brown Trout (Salmo trutta L.) Based on Otolith Microchemistry.

By analyzing otolith microchemistry, we examined the use of freshwater and marine environments by brown trout Salmo trutta L. that spawn in the Swedish River Emån and migrate to the Baltic Sea. We estimated the time juveniles spent in freshwater and the number of times the fish returned to freshwater, presumably to spawn. Twenty-six percent of the fish migrated to sea by 1 year of age. However, 13% spent less than one year in the river. Most brown trout (48%) migrated to the sea between 1 and 2 years of age. On average, brown trout, which averaged 4.4 years in age (range 3-6 years), returned to freshwater 2.3 times, and there was an inverse relationship between time spent in freshwater after hatching and the number of visits to freshwater. Our results do not support the classical life history pattern, where brown trout spend one or more years in freshwater before migrating to the sea. Here, we found evidence that part of the population leaves freshwater during their first year. While the cause for precocial migration in the River Emån is not known, our results from this permanently flowing river do not support the idea proposed for other Baltic Sea populations, where the risk of drought has been suggested to be the cause.

Incorporation of Zinc-Strontium Phosphate into Gallic Acid-Gelatin Composite Hydrogel with Multiple Biological Functions for Bone Tissue Regeneration.

Large bone defects resulting from fractures and diseases have become a significant medical concern, usually impeding spontaneous healing through the body's self-repair mechanism. Calcium phosphate (CaP) bioceramics are widely utilized for bone regeneration, owing to their exceptional biocompatibility and osteoconductivity. However, their bioactivities in repairing healing-impaired bone defects characterized by conditions such as ischemia and infection remain limited. Recently, an emerging bioceramics zinc-strontium phosphate (ZSP, Zn2Sr(PO4)2) has received increasing attention due to its remarkable antibacterial and angiogenic abilities, while its plausible biomedical utility on tissue regeneration is nonetheless few. In this study, gallic acid-grafted gelatin (GGA) with antioxidant properties was injected into hydrogels to scavenge reactive oxygen species and regulate bone microenvironment while simultaneously incorporating ZSP to form GGA-ZSP hydrogels. The GGA-ZSP hydrogel exhibits low swelling, and in vitro cell experiments have demonstrated its favorable biocompatibility, osteogenic induction potential, and ability to promote vascular regeneration. In an in vivo bone defect model, the GGA-ZSP hydrogel significantly enhanced the bone regeneration rates. This study demonstrated that the GGA-ZSP hydrogel has pretty environmentally friendly therapeutic effects in osteogenic differentiation and massive bone defect repair.

Distribution, risk evaluation, and source allocation of cesium and strontium in surface soil in a mining city.

Radioactive nuclides cesium (Cs) and strontium (Sr) possess long half-lives, with 135Cs at approximately 2.3 million years and 87Sr at about 49 billion years. Their persistent accumulation can result in long-lasting radioactive contamination of soil ecosystems. This study employed geo-accumulation index (Igeo), pollution load index (PLI), potential ecological risk index (PEPI), health risk assessment model (HRA), and Monte Carlo simulation to evaluate the pollution and health risks of Cs and Sr in the surface soil of different functional areas in a typical mining city in China. Positive matrix factorization (PMF) model was used to elucidate the potential sources of Cs and Sr and the respective contribution rates of natural and anthropogenic sources. The findings indicate that soils in the mining area exhibited significantly higher levels of Cs and Sr pollution compared to smelting factory area, agricultural area, and urban residential area. Strontium did not pose a potential ecological risk in any studied functional area. The non-carcinogenic health risk of Sr to the human body in the study area was relatively low. Because of the lack of parameters for Cs, the potential ecological and human health risks of Cs was not calculated. The primary source of Cs in the soil was identified as the parent material from which the soil developed, while Sr mainly originated from associated contamination caused by mining activities. This research provides data for the control of Cs and Sr pollution in the surface soil of mining city.

In vitro antifungal and physicochemical properties of polymerized acrylic resin containing strontium-modified phosphate-based glass.

Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans). Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups (p > 0.05), and the flexural strength was lower in the experimental groups than in the control group (p < 0.05), but no difference was found with Sr-PBG content (p > 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group (p < 0.05). This study demonstrated that 3.75% Sr-PBG exhibits antifungal effects against C. albicans along with suitable physicochemical properties, which may help to minimize the risk of adverse effects associated with harmful microbial living on removable orthodontic appliances and promote the use of various materials.

Geotraceability of Falanghina del Sannio (South Italy): Preliminary mineralogical and isotopic data.

The present study gathers mineralogical and isotopic geochemical data of 45 soil samples collected from the La Guardiense and Cantina di Solopaca wineries (Southern Italy) in order to provide useful information for the geotraceability of Falanghina white wine terroir. Mineralogical analyses show the ubiquitous presence of quartz, frequent and moderate contents of feldspars and phyllosilicates (i.e., illite/mica, kaolinite, and smectite). Rhizosphere soils from La Guardiense vineyards show a strontium isotope signature (87Sr/86Sr) ranging from 0.708604 to 0.711234 (average 0.710334; 1σ = 0.000943; n = 7) for the total fraction and a narrower range (from 0.706907 to 0.708807; average 0.708120; 1σ = 0.000641; n = 7) for the bioavailable one. For the rhizosphere soils collected from the vineyards of Cantina di Solopaca winery, 87Sr/86Sr ratios range from 0.708268 to 0.712413 (average 0.710145; 1σ = 0.001622; n = 8) and from 0.707968 to 0.709157 (average 0.708384; 1σ = 0.000409; n = 8) for the total and the bioavailable fraction, respectively. Actually, the bioavailable Sr fraction shows a narrower range of 87Sr/86Sr ratios compared to that of the total fraction, making the former more suitable for any study of wine traceability.