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In bone regeneration, combining natural polymer-based scaffolds with Bioactive Glasses (BGs) is an attractive strategy to improve the mechanical properties of the structure, as well as its bioactivity and regenerative potential. Methods: For this purpose, a well-studied alginate/hydroxyapatite (Alg/HAp) porous scaffold was enhanced with an experimental bioglass (BGMS10), characterized by a high crystallization temperature and containing therapeutic ions such as strontium and magnesium. This resulted in an improved biological response compared to 45S5 Bioglass®, the "gold" standard among BGs. Porous composite scaffolds were fabricated by freeze-drying technique and characterized by scanning electron microscopy and microanalysis, infrared spectroscopy, and microcomputed tomography. The mechanical properties and cytocompatibility of the new scaffold composition were also evaluated. The addition of bioglass to the Alg/HAp network resulted in a slightly lower porosity. However, despite the change in pore size, the MG-63 cells were able to better adhere and proliferate when cultured for one week on a BG scaffold compared to the control Alg/HAp scaffolds. Thus, our findings indicate that the combination of bioactive glass BGMS10 does not affect the structural and physicochemical properties of the Alg/HAp scaffold and confers bioactive properties to the structures, making the Alg/HAp-BGMS10 scaffold a promising candidate for future application in bone tissue regeneration. [ABSTRACT FROM AUTHOR]

Porous titanium exhibits low elastic modulus and porous structure is thought to be a promising implant in bone defect repair. However, the bioinert and low mechanical strength of porous titanium have limited its clinical application, especially in load‐bearing bone defect repair. Our previous study has reported an infiltration casting and acid corrosion (IC‐AC) method to fabricate a novel porous titanium (pTi) with 40% porosity and 0.4 mm pore diameter, which exerts mechanical property matching with cortical bone and interconnected channels. In this study, we introduced a nanoporous coating and incorporated an osteogenic element strontium (Sr) on the surface of porous titanium (named as Sr‐micro arch oxidation [MAO]) to improve the osteogenic ability of the pTi by MAO. Better biocompatibility of Sr‐MAO was verified by cell adhesion experiment and cell counting kit‐8 (CCK‐8) test. The in vitro osteogenic‐related tests such as immunofluorescence staining, alkaline phosphatase staining and real‐time polymerase chain reaction (RT‐PCR) demonstrated better osteogenic ability of Sr‐MAO. Femoral bone defect repair model was employed to evaluate the osseointegration of samples in vivo. Results of micro‐CT scanning, sequential fluorochrome labeling and Van Gieson staining suggested that Sr‐MAO showed better in vivo osteogenic ability than other groups. Taking results of both in vitro and in vivo experiment together, this study indicated the Sr‐MAO porous titanium could be a promising implant load‐bearing bone defect. [ABSTRACT FROM AUTHOR]

The increasing prevalence of implant‐associated infections (IAI) in orthopedics remains a public health challenge. Calcium phosphates (CaPs) are critical biomaterials in dental treatments and bone regeneration. It is highly desirable to endow CaPs with antibacterial properties. To achieve this purpose, we developed a photocrosslinked methacrylated alginate co‐calcium phosphate cement (PMA‐co‐PCPC) with antibacterial properties, using α‐tricalcium phosphate (α‐TCP) powders with 16% amorphous contents as solid phase, liquid phases containing CuCl2 and SrCl2 as an inhibitor, and CaCl2 as an activator to construct PCPC. When CaCl2 started to activate the hydration reaction, Sr2+ or Cu2+ ions were exchanged with Ca2+, and α‐TCP dissolution was restarted and gradually hydrated to form calcium‐deficient hydroxyapatite (CDHA). PMA was added to crosslink with Cu/Sr ions and form gel‐layer‐wrapped hydrated CDHA. This study explored the binding mechanism of PMA and PCPC and the ion release rule of Ca2+ → Sr2+/Cu2+, optimized the construction of several antibacterial PMA‐co‐PCPC materials, and analyzed the physical, chemical, and biological properties. Because of the combined effect of Cu and Sr ions, the scaffold exhibited a potential antibacterial activity, promoting bone formation and vascular regeneration. This work provides a basis for designing antibacterial calcium phosphate biomaterials with controllable treatment, which is an important characteristic for preventing IAI of biomaterials. [ABSTRACT FROM AUTHOR]

The Raman spectra of Ca1‐xSrxAl2Si2O8 (0 ≤ x ≤ 1) feldspars have been measured, to investigate at a short‐range scale the effect of changing composition on the P1¯ ➔ I1¯ and I1¯ ➔ I2/c phase transitions and how phase transitions affect the mechano‐luminescence found in these feldspars. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) were done on the same samples, to pinpoint the transitions, by the analysis of selected area diffraction patterns (SAED) and of the spontaneous strain. Natural anorthite (CaAl2Si2O8) shows a large number of well‐resolved peaks, together with sharp h + k even, l odd diffractions (c‐type) in SAED patterns, indicative of a P1¯ symmetry. In synthetic anorthite, the Raman spectrum is similar to that of natural anorthite, but the peaks are broader, and c‐type reflections are elongated. As Sr increases, the c‐type reflections become more diffuse and elongated, as the Raman peaks do. At x > 0.6, new peaks appear in Raman spectra, and other peaks show a change in their wavenumber. Moreover, the c‐type reflections disappear completely, and the lattice becomes I‐centred. Between x ~ 0.6 and x = 0.86(3), the XRD patterns prompt for a triclinic structure, with S.G. I1¯. The transition to the monoclinic I2/c structure is well constrained by the ferroelastic strain, whereas the Raman spectra are more similar between the monoclinic and triclinic I1¯ and I2/c than between I1¯ and P1¯. The absence of mechano‐luminescence in triclinic I1¯ compositions suggests that this property is enhanced in local P1¯ configurations at conditions close to the P1¯ to I1¯ transition. A possible mechanism for mechano‐luminescence involving a compression induced P1¯ to I1¯ transition in local Eu2+ bearing P1¯ configurations is proposed. [ABSTRACT FROM AUTHOR]

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The advancement of biomaterials for reconstruction and replacement of damaged tissues is essential, which would possess biocompatibility, better mechanical, biochemical, and physical properties. Merwinite (Ca3MgSi2O8) has emerged as a promising material for hard tissue engineering, particularly in composite with hydroxyapatite (HAp). Strontium-doped hydroxyapatite (SrHAp) was prepared with varying dopant concentrations (1%, 3%, and 5% Sr) on the calcium site of HAp. The materials were analyzed by XRD, FTIR and SEM/EDX techniques. XRD analysis revealed average crystallite sizes ranging from 46 to 50 nm for SrHAp. It was found that the Merwinite-SrHAp composite doped with 5% strontium had a higher rate of apatite nucleation compared to pure composite, indicating that strontium doping enhances the bioactivity of the composite. The composite scaffolds, prepared in an 80:20 ratio of SrHAp to merwinite, exhibited compressive strengths ranging from 63.43 MPa (1% Sr doping) to 80.68 MPa (5% Sr doping). Cytotoxicity assessment against MG63 cell line via MTT assay demonstrated cell inhibition rates ranging from 11.71% (at 6.5 μg/mL) to 68.35% (at 100 μg/mL) for the 5% Sr-doped composite. Alkaline phosphatase (ALP) investigation revealed enhanced ALP activity for cells cultured on the 5% Sr-doped composite compared to control samples, indicating increased cell differentiation and mineralization potential. [ABSTRACT FROM AUTHOR]

We present a comprehensive investigation into the concentration and temperature-dependent photoluminescence (PL) properties of europium ion (Eu3+) activated double-layered perovskite Sr3Ti2O7 materials. We conducted thorough analyses to assess their phase purity, crystal structure, surface morphology, and optical properties to gain a complete understanding. The double-layered perovskite Sr3Ti2O7:Eu3+ exhibited a tetragonal phase with space group I4/mmm. When excited by 395 nm ultraviolet (UV) light, the prepared materials exhibited a firm red emission peak at 616 nm, indicating the hypersensitive electric dipole transition 5D0 → 7F2 in Eu3+ ions. The quantum yield of the optimized sample was estimated to be 18%. To explore the temperature-dependent behavior of the photoluminescence, measurements were carried out over a wide range of temperatures from 300 K to 450 K. Notably, the phosphors demonstrated significant thermal stability, with 75% of the emission intensity retained at 420 K compared to 300 K. These findings signify the material's ability to maintain its luminescent properties at elevated temperatures. The photometric characterization of Sr3Ti2O7:Eu3+ further validated its red emission capability. Moreover, we employed the Judd–Ofelt approach to examine the radiative intensity parameters (Ω2, Ω4, Ω6). The obtained results provide substantial support for the promising prospects of this perovskite material in the rapidly growing field of solid-state lighting and display devices. [ABSTRACT FROM AUTHOR]

This research article explores the effect of chromium doping on the non-linear optical properties of strontium tungstate nanostructures. The study analyzes the samples using various techniques such as X-ray diffraction, FTIR, Raman spectroscopy, and photoluminescence studies. The results show that chromium-doped samples exhibit high non-linear absorption coefficient values, and the concentration of chromium affects the absorption behavior. The article also discusses the crystal structure, morphology, and optical properties of the doped nanostructures. The findings suggest that chromium-doped strontium tungstate nanostructures have potential applications in optical limiting and optical switching. [Extracted from the article]

In recent years, there has been a significant interest in the advancement of electrochemical sensing platforms to detect antipyretic drugs with high sensitivity and selectivity. The electrochemical determination of acetaminophen (PCT) was studied with strontium molybdate with a functionalized carbon nanotube (SrMoO4@f-CNF) nanocomposite. The SrMoO4@f-CNF nanocomposite was produced by a facial hydrothermal followed by sonochemical treatment, resulting in a significant enhancement in the PCT determination. The sonochemical process was applied to incorporate SrMoO4 nanoparticles over f-CNF, enabling a network-like structure. Moreover, the produced SrMoO4@f-CNF composite structural, morphological, and spectroscopic properties were confirmed with XRD, TEM, and XPS characterizations. The synergistic effect between SrMoO4 and f-CNF contributes to the lowering of the charge transfer resistance ( R c t = 85   Ω · c m 2 ), a redox potential of E p c = 0.15   V and E p a = 0.30   V (vs. Ag/AgCl), and a significant limit of detection (1.2 nM) with a wide response range of 0.01–28.48 µM towards the PCT determination. The proposed SrMoO4@f-CNF sensor was studied with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques and demonstrated remarkable electrochemical properties with a good recovery range in real-sample analysis. [ABSTRACT FROM AUTHOR]

The efficient segregation of radioactive nuclides from low-level radioactive liquid waste (LLRW) is paramount for nuclear emergency protocols and waste minimization. Here, we synthesized Na3FePO4CO3 (NFPC) via a one-pot hydrothermal method and applied it for the first time to the selective separation of Sr2+ from simulated LLRW. Static adsorption experimental results indicated that the distribution coefficient Kd remained above 5000 mL·g−1, even when the concentration of interfering ions was more than 40 times that of Sr2+. Furthermore, the removal efficiency of Sr2+ showed no significant change within the pH range of 4 to 9. The adsorption of Sr2+ fitted the pseudo-second-order kinetic model and the Langmuir isotherm model, with an equilibrium time of 36 min and a maximum adsorption capacity of 99.6 mg·g−1. Notably, the adsorption capacity was observed to increment marginally with an elevation in temperature. Characterization analyses and density functional theory (DFT) calculations elucidated the adsorption mechanism, demonstrating that Sr2+ initially engaged in an ion exchange reaction with Na+. Subsequently, Sr2+ coordinated with four oxygen atoms on the NFPC (100) facet, establishing a robust Sr-O bond via orbital hybridization. [ABSTRACT FROM AUTHOR]

Researchers often use trace element concentrations, including strontium–calcium ratios (Sr/Ca), to reconstruct paleodiets. While most commonly used as a proxy for meat consumption, a more appropriate application may be to differentiate frugivory from folivory. Sr/Ca ratios in animal tissue reflect the Sr/Ca ratios of the highest calcium components of that animal's diet. Because plants have much higher concentrations of calcium than meat, meat consumption signals are often overwhelmed by the variation in Sr/Ca ratios coming from different plant parts. This study uses faunal and plant data from Kibale National Park, a protected forest in southwestern Uganda home to numerous primate species (for example, common chimpanzees and baboons), to assess the reliability of Sr/Ca ratios to differentiate between primate dietary groups. We find that leaves consistently have higher strontium and calcium concentrations than fruits and that this is mirrored in higher Sr/Ca ratios in folivorous primates compared to frugivorous primates. Plant species differ widely in both their overall Sr/Ca ratios and the differences between their fruit and leaf Sr/Ca ratios, but this variation does not overwhelm the dietary signal separating frugivores and folivores. Furthermore, this research demonstrates that non-destructive and portable X-ray florescence (XRF) methods are an effective means of gathering Sr/Ca data from plant and faunal material, increasing the opportunities to apply such methods to fossil material in the future. [ABSTRACT FROM AUTHOR]

A parametric evaluation on a series of oxygen-deficient Co-rich La0.5Sr0.5Co0.8Fe0.2−xCuxO3−δ perovskite oxides (x = 0–0.20) is reported, for potential utility towards oxygen separation membrane and fuel cell application. Oxygen transport property is influenced by several parameters, including oxygen vacancy concentration, crystal structure, microstructure, electrical conductivity, and conductivity relaxation. X-ray photoelectron spectroscopy study revealed that oxygen nonstoichiometry in the prepared oxides increases with Cu-substitution level. The structural study confirmed that this material family has a cubic structure with Pm 3 - m space group with lattice size decreasing with increase in x. The microstructure of studied oxides showed that the average grain size of the sample considerably decreases with Cu-substitution. Iron substitution with copper remarkably enhances the electrical conductivity, which can be explained with defect chemistry. The bulk diffusion coefficient (Dchem) and surface exchange coefficient (Kchem) of La0.5Sr0.5Co0.8Fe0.2−xCuxO3−δ oxides were obtained using an electrical conductivity relaxation technique, and La0.5Sr0.5Co0.8Cu0.2O3−δ oxide was found to have higher Dchem (1.1 × 10−4 cm2 s−1) and Kchem (8.5 × 10−5 cm s−5) among them. This work demonstrates that the proposed Co-rich La0.5Sr0.5Co0.8Fe0.2−xCuxO3−δ perovskite with Cu-substitution level x = 0.20 can be considered a promising material for enhanced oxygen transport. [ABSTRACT FROM AUTHOR]

Radiocesium (r-Cs) and radiostrontium (r-Sr) released from nuclear accidents (e.g., Chornobyl, Fukushima) and routine operations (reactors, reprocessing) pose environmental and health concerns. Their primary pathway to humans is through plant uptake and subsequent bioaccumulation within the food chain. While soil amendments with potassium (K) and calcium (Ca) are known to mitigate r-Cs and r-Sr uptake, respectively, the impact on plant growth remains unclear. This study investigates the effects of Cs and Sr on the growth of Holcus lanatus L. seedlings under hydroponic and soil conditions with varying Cs and Sr concentrations. Stable isotopes of Cs and Sr served as non-radioactive analogs. Seedling growth was assessed across a range of Cs and Sr concentrations (≤1 and ≥4 mg L−1). The impact of the addition of K and Ca on Cs/Sr uptake in amended soils was also evaluated. Additionally, this study examined how Cs and Sr amendments affected the influx rates of other nutrients in H. lanatus. Higher Cs and Sr concentrations (≥4 mg L−1) significantly inhibited seedling growth, while lower concentrations had no effect. Notably, H. lanatus exhibited moderate Cs tolerance and strong Sr tolerance. Furthermore, K and Ca supplementation in Cs/Sr-amended soils demonstrably reduced plant uptake of these elements. This study also observed alterations in the uptake rates of other nutrients within H. lanatus due to Cs/Sr addition. This study suggests that H. lanatus exhibits moderate tolerance to Cs and Sr contamination, potentially making it suitable for revegetation efforts in contaminated grasslands. Additionally, K and Ca amendments show promise as a strategy to mitigate plant uptake of these radioisotopes further. These findings contribute to the development of safer revitalization strategies for areas impacted by nuclear accidents. [ABSTRACT FROM AUTHOR]

Simple Summary: Otoliths, calcified biomineralised structures in bony fish inner ear, are remarkable objects as keepers of individual life, both in terms of time and environment. Otolith microchemical analysis was undertaken with a synchrotron-based scanning X-ray fluorescence 2D high-resolution mapping method and we developed analytical imaging processes to retrieve biological information. Strontium incorporation in the otoliths of four pipefish species from Pacific island streams was analysed, as its presence in otoliths is a sign of life in a marine environment, while its absence corresponds to life in freshwater. Their life cycle is expected to be diadromous, allowing for species sustainability in labile and fragmented habitats. From a biological point of view, we uncovered the existence of plasticity in the diadromous life cycle, enhancing our knowledge of these poorly studied species, which are highly threatened by anthropogenic actions. In addition, our 2D hyperfine-scale images outlined the heterogeneity of strontium distribution in the otolith to a greater extent than what is generally assumed. Our results led us to uncover a trade-off in expression between the biological and chemical driving forces that govern element incorporation in the otoliths. Our methods and results provide a strong basis for future works and prospects in fish biology, ecology, and conservation. Indo-Pacific tropical island streams are home to freshwater pipefish (Microphis spp., Syngnathidae). Otoliths were used to uncover life history traits in four species, including a New Caledonian endemic. All four species present the same methodological challenge: their otoliths are small, fragile and mute for growth marks using basic observation tools. Strontium (Sr) is calcium substituent in the mineral lattice, driven by salinity conditions, and thus useful to study diadromous migrations. Synchrotron-based scanning X-ray fluorescence 2D high-resolution mapping allowed us to tackle the global and hyperfine strontium (Sr) distribution. We developed analytical imaging processes to retrieve biological information from otoliths from the data generated via synchrotron analysis. We uncovered plasticity in the life cycle: all species were amphidromous, apart from some freshwater residents from New Caledonia. Understanding life cycle modalities is crucial to categorize species distribution limits and to implement adapted conservation measures, especially when endemic species are at stake. 2D fine-scale images outlined the heterogeneity of Sr distribution: in addition to the trivial Sr incorporation driven by environmental ionic conditions, there is an unusual mosaic arrangement of Sr distribution and we hypothesize that biological control, especially growth during the early life stages, may sometimes overrule stoichiometry. This shows that it is worth studying otolith formation and element integration at imbricated scales, and our methods and results provide a strong basis for future works and prospects in otolith science. [ABSTRACT FROM AUTHOR]

Oxidative dehydrogenation (ODH) of light alkanes to produce C2−C3 olefins is a promising alternative to conventional steam cracking. Perovskite oxides are emerging as efficient catalysts for this process due to their unique properties such as high oxygen storage capacity (OSC), reversible redox behavior, and tunability. Here, we explore AFeO3 (A=Ba, Sr) bulk perovskites for the ODH of ethane and propane under chemical looping conditions (CL‐ODH). The higher OSC and oxygen mobility of SrFeO3 perovskite contributed to its higher activity but lower olefin selectivity than its Ba counterpart. However, SrFeO3 perovskite is superior in terms of cyclic stability over multiple redox cycles. Transformations of the perovskite to reduced phases including brownmillerite A2Fe2O5 were identified by X‐ray diffraction (XRD) as a cause of performance degradation, which was fully reversible upon air regeneration. A pre‐desorption step was utilized to selectively tune the amount of lattice oxygen as a function of temperature and dwell time to enhance olefin selectivity while suppressing CO2 formation from the deep oxidation of propane. Overall, SrFeO3 exhibits promising potential for the CL‐ODH of light alkanes, and optimization through surface and structural modifications may further engineer well‐regulated lattice oxygen for maximizing olefin yield. [ABSTRACT FROM AUTHOR]

A challenge in tissue engineering and the pharmaceutical sector is the development of controlled local release of drugs that raise issues when systemic administration is applied. Strontium is an example of an effective anti-osteoporotic agent, used in treating osteoporosis due to both anti-resorptive and anabolic mechanisms of action. Designing bone scaffolds with a higher capability of promoting bone regeneration is a topical research subject. In this study, we developed composite multi-layer three-dimensional (3D) scaffolds for bone tissue engineering based on nano-hydroxyapatite (HA), Sr-containing nano-hydroxyapatite (SrHA), and poly-ε-caprolactone (PCL) through the material extrusion fabrication technique. Previously obtained HA and SrHA with various Sr content were used for the composite material. The chemical, morphological, and biocompatibility properties of the 3D-printed scaffolds obtained using HA/SrHA and PCL were investigated. The 3D composite scaffolds showed good cytocompatibility and osteogenic potential, which is specifically recommended in applications when faster mineralization is needed, such as osteoporosis treatment. [ABSTRACT FROM AUTHOR]

We investigated enhancing the electro-optical properties of thin films by doping them with graphene oxide (GO) following the fabrication of a zirconium strontium tin oxide solution via the sol–gel method. GO was doped into inorganic materials at 0, 5, and 15 wt%, respectively. The characteristics of the resulting thin films were analyzed based on doping ratio. Our study confirmed significant improvements in electrical properties through accelerated reaction speeds via response time vs. transmission measurements and notably enhanced T90 transmittance values in voltage–transmission measurements. X-ray photoelectron spectroscopy was employed to analyze the chemical composition of the thin film surfaces, revealing the impact of graphene's carbon isomer nature and the oxygen environment. Furthermore, changes in surface roughness were assessed using atomic force microscopy, validating the alterations in properties. Finally, the thin film's suitability for display devices was confirmed through transmittance measurements. [ABSTRACT FROM AUTHOR]

M-type hexagonal ferrites were produced using the citrate auto-combustion technique. To understand the effects of substituting divalent Co2+ and rare earth elements Dy3+ on the structure, magnetic and removal efficiency of hexagonal ferrites, a series of samples including SrFe12O19, SrFe11.5Co0.5O19, Sr0.95Dy0.05Fe12O19, Sr0.95Dy0.05Fe11.5Co0.5O19 were analyzed. XRD analysis showed that all samples crystallized into a single M-type hexagonal phase. The small wavenumber absorption bands between 400 and 1000 cm−1 in FTIR curves are the primary features of M-type hexagonal ferrites. Magnetic properties varied with the addition or removal of Dy3+ and Co2+ doping due to the impact of spin canting with Dy3+ and Co2+ ions on strontium and iron ions. The study aimed to gather information about doping magnetic hexaferrites, which could be a pioneering development in wastewater treatment. The study examined the impact of substitution with rare earth and divalent elements in wastewater treatment, along with potential future developments in this field. The study examined various factors affecting the adsorption of lead ions from aqueous solutions, such as pH and contact time. The maximum removal efficiency of Sr0.95Dy0.05Fe11.5Co0.5O19 was approximately 99.6% at pH 7 and 25 °C after 60 min. The isotherm data fit into the Frendlish isotherm approach. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models clarified the adsorption kinetics. The capacity for adsorption of the studied samples was consistent and demonstrated through 4 cycles. [ABSTRACT FROM AUTHOR]

Solar thermochemical hydrogen (STCH) production from water splitting typically requires performing redox cycles at temperatures above 1200 °C to reduce and re-oxidize the bulk of a reversible material. Bulk processes such as oxygen vacancy formation and oxygen diffusion energies dictate the viability of a material for STCH. The surface plays an important role in the formation and destruction of vacancies and interacts with gas phase water and surface adsorbed species. These surface processes can lead to surface reconfigurations and even the formation of surface phases with stoichiometry and oxygen content very different from the bulk composition. Understanding in-situ the surface chemical state and its evolution under water splitting is important to design nonstoichiometric oxides capable of longer-lasting STCH generation at lower temperatures. In this work, we describe the water splitting active defect sites in LSM ((La0.65Sr0.35)0.95MnO3−δ) and Ga-doped LSM ((La0.6Sr0.4)0.95(Mn0.8Ga0.2)O3−δ) perovskites during Operando thermochemical water splitting conditions using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) experiments at 800 °C under steam. We show that sub-stoichiometric La+3 in the oxygen-vacancy rich surface at operating conditions can be used to correlate surface water splitting activity and the creation of surface hydroxide intermediates. The addition of Ga in LSM is shown to drastically stabilize the surface chemical composition by preventing Sr segregation and stabilizing catalytically active surface defects that promote the binding of adsorbed hydroxides. We use Operando AP-XPS quantification of metastable surface hydroxide intermediates (La(OH)3) to determine the amount of catalytically active surface sites in LSM (2.9%) and in LSMG (7.8–8.1%, depending on the bulk oxidation state). [ABSTRACT FROM AUTHOR]

In this communication, the synthesis and characterizations of modified strontium manganate (SrCu1/3Mn1/3W1/3O3) (SCMWO) by high‐temperature solid‐state method are reported. The structural analysis predicts a monoclinic structure with a crystallite size of 36.8 nm. The analysis of the Raman active modes reveals the presence of all the constituent atomic vibrations. The study of the ultraviolet–visible spectrum provides a bandgap energy of 1.71 eV, which may be suitable for photovoltaic applications. A Maxwell‐Wanger type of polarization effect is observed at low frequency while low dielectric loss makes the material suitable for energy storage devices. The study of the impedance plots reveals the negative temperature coefficient of resistance (NTCR) character. The activation energy increases with both frequency and temperature in the modified perovskite suggesting that conductivity of the sample increases and material characters are changing from dielectric to semiconducting. The symmetrical curves in the electrical modulus plots and shift toward higher frequency region agree with the results of the non‐Debye‐type of relaxation mechanism. The semicircular curves in the Cole–Cole plots confirm the semiconducting nature and are also well supported by the results of Nyquist plots. The studied material exhibits a semiconductor nature, which may be found suitable for energy storage device applications. [ABSTRACT FROM AUTHOR]

In the study, the mechanical properties of aluminum alloys produced by the injection molding method, especially using Strontium and Titanium metals, were optimized without being subjected to cold forming. Mechanical tests were applied to the alloys produced by the high-pressure casting technique, and their strength, hardness, and microstructure were examined. Optical and SEM microscopy examinations investigated grain structures. Within the scope of the study, AlTi5B1 master alloy and AlSr10 master alloy were added to the pure AlSi10 (Fe) alloy in 5 different compositions. AlTi5B1 master alloy added to pure AlSi10(Fe) alloy significantly increased the hardness by reducing the grain size. Si modification took place with the addition of AlSr10 master alloy, and it was observed that the obtained weight ratios of 150ppm, 300ppm, and 450ppm Sr increased the hardness proportionally by 2.5 HB each. With the increase in Ti and Sr master alloys added, a significant increase was observed in tensile and yield strengths and % elongation rates. In the compression test, the percentage (%) deformation elongation, the reduction of the grain structure of the material by the added Ti and Sr elements, and the transformation of the eutectic silicon into a spherical structure absorbed the applied Fm force. This led to an increase in strength, and while the permanent deformation elongation decreased as the weight of Ti increased, it was observed that the permanent deformation elongation decreased proportionally with each added amount of 150 ppm Sr. The addition of the Ti element reduced the grain size by shrinking the α-Al dendrites, but it did not affect the eutectic Si. [ABSTRACT FROM AUTHOR]

It is well established that Cretaceous magmatism in the South China Block (SCB) is related to the Paleo‐Pacific subduction. However, the starting time and the associated deep crust‐mantle processes are still debatable. Mafic dike swarms carry important information on the deep earth (including mantle) geodynamics and geochemical evolution. In the Jiangnan Orogen (South China), there is no information on whether the Mesozoic magmatic activities in this region are also directly related to the Pacific subduction or not. In this study, we present detailed zircon U‐Pb geochronological, whole‐rock element and Sr‐Nd isotope data for Early Cretaceous Tuanshanbei dolerite dikes, and provide new constraints on the condition of the lithospheric mantle and mantle dynamics of the SCB during that time. LA‐ICP‐MS zircon U‐Pb dating suggests that this dolerite erupted in the Early Cretaceous (∼145 Ma). All samples have alkaline geochemical affinities with K2O + Na2O = 3.11–4.04 wt%, K2O/Na2O = 0.50–0.72, and Mg# = 62.24–65.13. They are enriched in LILE but depleted in HFSE with higher initial 87Sr/86Sr ratio (0.706896–0.714743) and lower εNd(t) (–2.61 to –1.67). They have high Nb/U, Nb/La, La/Sm and Rb/Sr, and low La/Nb, La/Ta, Ce/Pb, Ba/Rb, Tb/Yb and Gd/Yb ratios. Such geochemical signatures suggest that the fractional crystallization is obvious but crustal contamination play a negligible role during magmatic evolution. Tuanshanbei dolerite were most likely derived from low‐degree (2%–5%) partial melting of a phlogopite‐bearing mantle material consisted of ∼85% spinel peridotite and ∼15% garnet peridotite previously metasomatized by asthenosphere‐derived fluids/melts with minor subduction‐derived fluids/melts. Slab‐rollback generally lead to the upwelling of the hot asthenosphere. The upwelling of asthenosphere consuming the lithospheric mantle by thermo‐mechanical‐chemical erosion. The lithospheric mantle may have partially melted due to the heating by the upwelling asthenosphere and lithospheric extension. It is inferred that the Tuanshanbei dolerite might be associated with the initial slab rollback and corresponding lithospheric extension occurred potentially at ca. 145 Ma. [ABSTRACT FROM AUTHOR]

The complete oxidation of propene was done by using a series of MnAl and Sr-doped MnAl catalysts prepared by deposition precipitation followed by the coprecipitation method. The concentration of Mn2O3 and SrAl2O4 active phases increases with the relative content of reactive oxygen species. These species enhance the reducibility of catalysts, which further increases the activity of C3H6 oxidation at relatively low temperatures. Characterization techniques like X-ray diffraction, FTIR, BET, X-ray photoelectron spectroscopy, temperature-programmed reduction, high-resolution transmission electron microscopy and 27Al NMR were used to determine the physicochemical characteristics of the catalysts. The complete propene oxidation activity was observed on MnSr0.3Al at 237°C. The effect of preparation methods indicates that the coprecipitation followed by the deposition precipitation approach strengthens the interaction between Sr and Mn. It also improved the dispersion of Sr and Mn on the surface of Al2O3 compared to the successive impregnation and deposition precipitation method. [ABSTRACT FROM AUTHOR]

In this work, we analyze the electrical behavior of strontium ferromolybdate below room temperature. We demonstrate that in SFMO ceramics, SFMO thin films deposited by pulsed laser deposition including (100) and (111) textured thin films, as well as in nonstoichiometric SFMO ceramics, an intergrain tunneling mechanism of charge carrier conduction leads to a decrease in resistivity with increasing temperature in the low-temperature region. This intergrain tunneling can be attributed to fluctuation-induced tunneling. On the other hand, bulk metallic resistivity of the grains, which increases with temperature, becomes dominant at higher temperatures and magnetic fluxes. The interplay of these conduction mechanisms leads to a resistivity minimum, i.e., a resistivity upturn below the temperature of minimum resistivity. Several mechanisms have been discussed in the literature to describe the low-temperature upturn in resistivity. Based on available literature data, we propose a revised model describing the appearance of a low-temperature resistivity minimum in SFMO ceramics by an interplay of fluctuation-induced tunneling and metallic conductivity. Additionally, we obtained that in the region of metallic conductivity at higher temperatures and magnetic fluxes, the pre-factor Rm of the temperature-dependent term of metallic conductivity written as a power law decreases exponentially with the temperature exponent m of this power law. Here, the value of m is determined by the charge scattering mechanism. [ABSTRACT FROM AUTHOR]

The hydrochemical characteristics of river water are influenced by a multitude of factors, reflecting the surrounding geographical environment. The Shaliu River, located in the northeastern Tibetan Plateau (TP), serves as a typical inland alpine permafrost watershed. In this study, we compiled data on dissolved strontium (Sr) concentration, 87Sr/86Sr isotopic, and hydrochemical profiles from the Shaliu River during the ablation period (May–October). Additionally, we gathered information on the Sr concentration and 87Sr/86Sr in the sediment of the river. The pattern of spatial heterogeneity in observed strontium (Sr) compositions can largely be attributed to lithological characteristics encountered at different locations along the river. The chemical components of Sr in the waters are derived from a combination of carbonate and silicate materials, with carbonates contributing between 69% and 81% and silicates contributing 19%–31%. The annual dissolved Sr flux is estimated to be 132 t/a. In addition to the influence of lithology and weathering processes, we propose that freeze‐thaw cycles within the permafrost layer may significantly affect the chemical mass flux in alpine permafrost watersheds because they generate substantial amounts of loose and easily erodible materials. Climate warming may further intensify the weathering processes in these watersheds, potentially leading to an increase in the Sr flux. This study is crucial for developing a comprehensive understanding of the geochemical composition of dissolved solutes in alpine permafrost regions, as well as for identifying the factors that regulate river water chemistry. Plain Language Summary: Understanding the sources and processes of radiogenic Sr has been a longstanding focus of research. The Shaliu River is a typical inland alpine permafrost watershed on the northeastern Tibetan Plateau. This study presents data on dissolved strontium (Sr) concentration, 87Sr/86Sr, isotopic ratios, and hydrochemical profiles from the Shaliu River during the ablation period (May–October). The main findings of the study are as follows: (a) The chemical components of Sr in the waters are derived from a combination of carbonate and silicate materials, with carbonates contributing between 69% and 81% and silicates contributing 19%–31%; (b) Secondly, the annual dissolved Sr flux is estimated to be 132 t/a; (c) In addition to the influence of lithology and weathering processes, we propose that freeze‐thaw cycles within the permafrost layer may significantly affect the chemical mass flux in alpine permafrost watersheds due to the generation of substantial amounts of loose and easily erodible materials. Key Points: Strontium (Sr) in the Shaliu River waters comes from a mix of carbonates (69%–81%) and silicates (19%–31%)The annual dissolved Sr flux is estimated to be 132 t/aThe freeze‐thaw processes of the permafrost layer have a profound influence on alpine permafrost watersheds under a warming climate [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) is a leading cause of death worldwide. Few drugs hold the ability to depress cardiac electrical and structural remodeling simultaneously after MI, which is crucial for the treatment of MI. The aim of this study is to investigate an effective therapy to improve both electrical and structural remodeling of the heart caused by MI. Here, an "ion cocktail therapy" is proposed to simultaneously reverse cardiac structural and electrical remodeling post‐MI in rats and minipigs by applying a unique combination of silicate, strontium (Sr) and copper (Cu) ions due to their specific regulatory effects on the behavior of the key cells involved in MI including angiogenesis of endothelial cells, M2 polarization of macrophages and apoptosis of cardiomyocyte. The results demonstrate that ion cocktail treatment attenuates structural remodeling post‐MI by ameliorating infarct size, promoting angiogenesis in both peri‐infarct and infarct areas. Meantime, to some extent, ion cocktail treatment reverses the deteriorative electrical remodeling by reducing the incidence rate of early/delayed afterdepolarizations and minimizing the heterogeneity of cardiac electrophysiology. This ion cocktail therapy reveals a new strategy to effectively treat MI with great clinical translation potential due to the high effectiveness and safety of the ion cocktail combination. [ABSTRACT FROM AUTHOR]

Crown ethers are famous for the highly selectively grab Sr(II) from concentrated nitric acid solution due to the size match, but they suffer from the high leakage into the liquid phase caused by the presence of a large number of hydrophilic groups. To reduce their leakage, two novel porous silica-based adsorbents, (DtBuCH18C6 + Dodec)/SiAaC-g-ABSA and (DtBuCH18C6 + Dodec)/SiAaC-g-3-ABSA, were prepared by vacuum impregnation with organic contents of about 55.9 wt.% and 56.1 wt.%, respectively. The two adsorbents have good reusability and structural stability, and the total organic carbon leakage rates in 2 M HNO3 solution are lower than 0.56 wt.% and 0.29 wt.%, respectively. Batch adsorption experiments revealed that the two adsorbents possessed good adsorption selectivity towards Sr, with SFSr/M over 40, except that of SFSr/Ba in 2 M HNO3 solution. The adsorption equilibrium of Sr in 2 M HNO3 solution was reached within 1 h, with saturated adsorption capacities of 36.9 mg/g and 37.5 mg/g, respectively. Furthermore, the XPS results indicate that the adsorption mechanism is the coordination of the crown ether ring with Sr. This work not only develops two novel adsorbents for the separation of Sr in nitric acid environments; it also provides a method for effectively reducing the water solubility of crown ethers. [ABSTRACT FROM AUTHOR]

In this investigation, perovskite La0·8Sr0·2FeO3 nanocrystals were cultivated within heavy metal oxide glass, utilizing Al2O3 tailoring. The study delves into the impact of La0·8Sr0·2FeO3 formation on both the glass structure and optical/magnetic properties. Employing diverse techniques such as x-ray diffraction, Raman spectroscopy, x-ray photoelectron microscopy, electron paramagnetic resonance, nuclear magnetic resonance and Mössbauer spectra, we scrutinized these influences. The synthesis resulted in well-distributed, orthogonal La0·8Sr0·2FeO3 nanocrystals measuring 10-30 nm within the glass matrix. This crystallization induced alterations in the structure and coordination numbers of B2O3, Al2O3 and Bi2O3. Notably, the introduction of 10% Al2O3 in the glass manifested an abnormality effect, showcasing the highest transparency, the smallest La0·8Sr0·2FeO3 size (10 nm), and minimal nonbridging oxygen defects. Remarkably, the glass with 10% Al2O3 demonstrated an intriguing aluminium-induced effect, exhibiting the highest transparency, the smallest La0·8Sr0·2FeO3 size (10 nm), and the least nonbridging oxygen defects. Furthermore, this glass exhibited an enhanced electron paramagnetic resonance signal, the highest percentage (71%) of tetrahedral FeO4 units and an improved Mössbauer sextets intensity, making it particularly promising for applications in photonics devices. [ABSTRACT FROM AUTHOR]

In the field of crop research, the study of roots involves many challenges, particularly the lack of effective methods for identifying crop roots. To deal with this problem, this study proposes a solution strategy: in applying strontium to crop leaves, the roots of different crops are distinguished. In this study, we applied strontium ions to the leaves of hydroponically grown wheat, and these strontium ions were partially absorbed by the leaves and transported to the roots. Therefore, the strontium concentration of roots was significantly increased through the foliar application of strontium. After mixing the treated wheat with the untreated wheat root, the greater the biomass of the wheat root applied with strontium ions, the higher the strontium concentration in the mixed root. Based on this phenomenon, we can establish the relationship between wheat root biomass and strontium concentration in mixed roots through linear fitting. Furthermore, we can also use the relationship between root biomass and root length to establish the correlation between strontium concentration in mixed roots and the root length of wheat with strontium ions. After measuring the strontium concentration of the mixed roots to be distinguished, the root biomass and root length of wheat applied with strontium ions can be calculated according to the equation obtained through linear fitting. The accuracy of this method was verified through a comparison with the actual value and the existing root staining method. The results show that the coefficient of determination (R2) of the root biomass estimation equation obtained through linear fitting reached 0.83, which is statistically significant (p < 0.01). The Pearson correlation coefficient with the measured value was more than 0.9, showing a very high correlation and significance. The root length estimation equation derived from the relationship between the root biomass, strontium concentration and root length was compared with the real root length value and the root length value obtained using the staining method. The Pearson correlation coefficient also exceeded 0.8 and reached a statistically significant level (p < 0.01). This study confirms that strontium ions can be absorbed and transported to roots through wheat leaves and successfully developed a new method for predicting the length of wheat roots, providing an effective new tool for wheat root research. [ABSTRACT FROM AUTHOR]

Powder-Mixed Electrical Discharge Machining (PM-EDM) is one of the latest advancements in EDM process capability augmentation. This procedure involves effectively mixing a suitable material in fine powder form with the dielectric fluid. The dielectric fluid's breakdown properties are enhanced by the additional powder. The objective of the present research is to machine the Ti-35Nb-7Zr-5Ta alloy prepared by powder metallurgy and study the influence of process parameters, such as peak current, pulse-on time, pulse-off time, powder type (Ag, Si, Ag+Si), and powder concentration. The metal removal rate and SR represent the response parameters. The Taguchi approach was followed to design the experiments. The five-factor three-level design was chosen to use the Taguchi L27 orthogonal array. It was found that the addition of Ag, Si, or Ag+Si powders to the dielectric fluid enhanced the metal removal rate and the surface finish for this alloy. The addition of Ag powder to the dielectric fluid gave a higher Material Removal Rate (MRR) and a lower SR compared to Si or Ag+Si powders. Powder concentration and pulse current are the most effective parameters on MRR and SR followed by powder type, pulse-on, and pulse-off. The maximum Grey Relational Grade (GRG) exists at (I=5 A, Ton=9 µs, Toff=37 µs, PT=Ag, PC=20 g/L). These are the optimal conditions for PM-EDM of the Ti-35Nb-7Zr-5Ta alloy that give maximum MRR with minimum SR. [ABSTRACT FROM AUTHOR]

A large variety of chemical and physical properties are exhibited by mercurides and amalgams. In this work, we have successfully examined seven strontium mercurides: SrHg11, SrHg8, Sr10Hg55, SrHg2, SrHg, Sr3Hg2, and Sr3Hg. The interest in the mercury-rich region is motivated by the large number of mercury-based superconductors that have high mercury content. At the same time, the preparation on the mercury-rich side of the binary phase diagram is experimentally non-trivial, due to the high vapor pressure of mercury and extreme air-sensitivity of mercury-rich compounds. By employing a set of specialized techniques, we were able to discover superconductivity in three mercury-strontium compounds – SrHg11 (Tc=3.2±0.3 K, Hc2=0.18±0.05 T), SrHg8 (Tc=3.0±0.1 K, Hc2=0.35±0.02 T), and Sr10Hg55 (Tc=2.2±0.25 K, Hc2=0.54±0.05 T).

Abstract Objectives This study aimed to investigate the osseointegration of titanium (Ti) implants with micro-nano textured surfaces functionalized with strontium additions (Sr) in a pre-clinical rat tibia model. Methodology Ti commercially pure (cp-Ti) implants were installed bilaterally in the tibia of 64 Holtzman rats, divided into four experimental groups (n=16/group): (1) Machined surface - control (C); (2) Micro-nano textured surface treatment (MN); (3) Micro-nano textured surface with Sr2+ addition (MNSr); and (4) Micro-nano textured surface with a higher complementary addition of Sr2+ (MNSr+). In total, two experimental euthanasia periods were assessed at 15 and 45 days (n=8/period). The tibia was subjected to micro-computed tomography (μ-CT), histomorphometry with the EXAKT system, removal torque (TR) testing, and gene expression analysis by PCR-Array of 84 osteogenic markers. Gene expression and protein production of bone markers were performed in an in vitro model with MC3T3-E1 cells. The surface characteristics of the implants were evaluated by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and laser scanning confocal microscopy. Results SEM, confocal, and EDS analyses demonstrated the formation of uniform micro-nano textured surfaces in the MN group and Sr addition in the MNSr and MNSr+ groups. TR test indicated greater osseointegration in the 45-day period for treated surfaces. Histological analysis highlighted the benefits of the treatments, especially in cortical bone, in which an increase in bone-implant contact was found in groups MN (15 days) and MNSr (45 days) compared to the control group. Gene expression analysis of osteogenic activity markers showed modulation of various osteogenesis-related genes. According to the in vitro model, RT-qPCR and ELISA demonstrated that the treatments favored gene expression and production of osteoblastic differentiation markers. Conclusions Micro-nano textured surface and Sr addition can effectively improve and accelerate implant osseointegration and is, therefore, an attractive approach to modifying titanium implant surfaces with significant potential in clinical practice.

Abstract The objective was to evaluate the effect of oral administration of strontium (Sr) on the regeneration of a critical bone defect. Twenty Wistar rats were divided into two groups, assessed at 15 and 60 days postoperatively: GSr - oral administration of Sr; and CG - without oral administration of Sr. At 15 and 60 days, blood was collected to measure Sr and calcium (Ca), and the calvaria was removed for histomorphological and histomorphometric analyses. Sr+2 plasmatic concentrations were higher in GSr than in CG. The dosage of Ca+2 showed a small increase in the CG about the GSr. In all evaluated groups, new bone formation was restricted to the edges of the defect, and the residual area was filled with fibrous connective tissue. The oral administration of Sr associated with HA microspheres substituted by the metal, in a concentration of 23 mol%, did not affect the formation of the osteoid matrix.

Multiple-step nucleation pathways have been observed during mineral formation in both inorganic and biomineral systems. These pathways can involve precursor aqueous species, amorphous intermediates, or metastable phases. Despite the widespread occurrence of these processes, elucidating the precise nucleation steps and the transformation mechanisms between each step remains a challenging task. Using a suite of potentiometric, microscopic, and spectroscopic tools, we studied the nucleation pathway of SrSO4 as a function of the physico-chemical solution parameters. Our observations reveal that below a threshold supersaturation, nucleation is driven by bound species, akin to the prenucleation cluster model, which directly leads to the formation of the stable phase celestine, SrSO4. At higher supersaturations, this situation is altered, with nucleation dominated by the consumption of free ions. Importantly, this change in nucleation mechanism is coupled to the formation of a hemihydrate metastable phase, SrSO4 · 1/2H2O, which eventually transforms into celestine, adhering to Ostwald's rule of stages. This transformation is a solution-mediated process, also occurring in the presence of a fluid film and is controlled by the physico-chemical parameters of the surrounding environment. It proceeds through the dissolution of the metastable phase and the de novo crystallization of the final phase. Overall, our results reveal that ion association taking place during the prenucleation stage dictates whether the nucleation pathway goes through an intermediate phase or not. This also underlines that although Ostwald's rule of stages is a common process, it is not a prerequisite for mineral formation—even in systems where it can occur. [ABSTRACT FROM AUTHOR]

It is one of the effective strategies to develop intermediate-temperature solid oxide fuel cells (IT-SOFCs) by looking for alternative electrolyte materials that can maintain or even improve current cell efficiencies while reducing operating temperature. In this study, by rationally introducing pentavalent Nb on the B-site of La0.6Sr0.4FeO3−δ (LSFO), a serial of novel perovskite La0.6Sr0.4Fe1−xNbxO3−δ (LSFNbx, x = 0.1, 0.2) with mixed electron-ion conduction is successfully prepared. The electrochemical mechanism and performance of the symmetrical IT-SOFCs with a single LSFNbx perovskite oxide as electrolyte are investigated. With the Nb doping, the structure stability of the LSFO is improved and the electronic conductivity decreases. La0.6Sr0.4Fe0.8Nb0.2O3−δ (LSFNb20) is the most promising electrolyte of the three candidates as it has the best performance (735 mW cm−2 at 550 °C in a dry H2/Air atmosphere) and no short-circuiting problem. The applied voltage-response current curves demonstrate that the interface between the Ni-Ni0.8Co0.15Al0.05LiO2−δ anode and LSFNb20 electrolyte can block electron conduction more efficiently and has a better promoting effect on protons, which is fundamentally due to the band energy alignment of the interface heterojunction. Our work highlights that LSFNb20 is a high-performance perovskite alternative to monolayer electrolytes. [ABSTRACT FROM AUTHOR]

Strontium(Sr) is a trace element naturally found in the human skeletal system. In recent years, the potential impact of strontium on bone and cardiovascular health has called significant attention, particularly during pregnancy, when alterations in mineral metabolism may affect the health of both the mother and the fetus. This comprehensive review assesses the current understanding of the role of strontium as a nutritional substance during pregnancy, its effects on maternal health and fetal development, and its potential associations with pregnancy complications such as preeclampsia, gestational hypertension, and lactation-induced osteoporosis. The review also summarizes the possible effects of strontium deficiency, excess, and supplementation, and provides information for developing prenatal nutrition supplementation guideline.

Introduction. In this work, Sr-BDC MOFs were obtained by a simple solvothermal process without the use of elevated pressure. This method is easily scalable and does not require any special equipment. In this work, the crystals obtained from the synthesis were studied by Raman spectroscopy. In addition, the obtained materials were analysed for antibacterial activity against Gram-positive and against Gram-negative bacteria.Aim. During this work, the main objective was to comparatively evaluate the antibacterial properties of Sr-BDC MOFs activated by different methods (and without activation).Materials and methods. In this work we used a solvothermal process using terephthalic acid, strontium nitrate and dimethylformamide. The peculiarity of this method is the absence of autoclaving in the synthesis process. Optical microscopy and Raman spectroscopy were used for characterization. Also, to study the antibacterial properties, a medium diffusion test was performed. The combination of these methods will help to establish the relationship between the method of activation and the biological activity of the resulting materials.Results and discussion. In this work, the chemical structure of Sr-BDC MOFs was studied by Raman spectroscopy. The influence of the activation method on the chemical structure of MOFs was studied. It was found that the characteristic peaks of Raman spectroscopy can be used to confirm the removal of solvent (DMFA) from the crystal structure. In addition, tests on the manifestation of antibacterial activity were carried out for MOFs with different activation method. The MIC and MBC were established for each sample.Conclusion. In the course of the work the effect of the activation method on the chemical structure of Sr-BDC MOFs was shown. We also found that the activation method could affect the biological activity of the obtained MOFs. It was also demonstrated that MOFs exhibit different antibacterial activities depending on the type of bacteria, which can be primarily related to the composition of the cell wall of microorganisms.

In this study, graphene oxide (GO) adsorbent was prepared by modified Hummer’s method and functionalized with aminomethylphosphonic acid. Its application to the adsorption of Sr ions from aqueous solutions in a batch sorption process was investigated. Adsorbents were characterized by TEM and FT-IR. The TEM images of functionalized graphene oxide showed that graphene sheets are formed in wavy sheets. The FTIR spectrum revealed that graphene oxide was highly functionalized with aminomethylphosphonic acid and oxygenated functional groups were reduced. Response surface methodology investigates pH, adsorbent dosage, and temperature parameters. The quadratic model corresponds well with the experimental data. The results illustrated that there is no systematic error in the experiments. The verification of the model with random experiments showed a low error in the values predicted by the model. The kinetic data were analyzed by Pseudo-first-order, Pseudo-second-order, and Double- exponential kinetic models, and experimental data were well modeled by the pseudo-second-order kinetic model. The research results showed that graphene oxide functionalized with aminomethylphosphonic acid has a good ability to strontium adsorption from aqueous solutions.

Due to the importance of removing strontium ions in nuclear wastes, in the present work, while synthesizing hydroxybenzaldehyde propyltriethoxysilane ((EtO)3Si-HL) and pyridylmethylidene propyltriethoxysilane ((EtO)3Si-L) ligands, we investigated the properties of silica nanoparticles modified with these ligands as solid adsorbents in The removal of strontium ion from the aqueous solution was investigated and parameters such as pH, time, the mass of adsorbent, temperature, and interfering ions were tested. The adsorption behavior of the adsorbents showed that by modifying the surface of the nano adsorbent, the ability of the adsorbents to adsorb strontium ion at pH=6 increased from 6.31% to 86% and 22.11% using the (EtO)3Si-HL and (EtO)3Si-L ligands, respectively. The results of isotherms and adsorption kinetics indicate that the adsorption process follows the Longmuir isotherm and the pseudo-second-order model, respectively. Also, thermodynamic parameters show that strontium removal from the aqueous solution is an endothermic process. The positive entropy values are the driving force behind the adsorption process.

Abstract Background Strontium (Sr) has similar physicochemical properties as calcium (Ca) and is often used to evaluate the absorption of this mineral. Because the major route of Ca absorption in the bovine occurs in the rumen, it is essential to understand whether Sr impacts the ruminal epithelial cells and to what extent. Results In the present study, RNA sequencing and assembled transcriptome assembly were used to identify transcription factors (TFs), screening and bioinformatics analysis in bovine ruminal epithelial cells treated with Sr. A total of 1405 TFs were identified and classified into 64 families based on an alignment of conserved domains. A total of 174 differently expressed TFs (DE-TFs) were increased and 52 DE-TFs were decreased; the biological process-epithelial cell differentiation was inhibited according to the GSEA-GO analysis of TFs; The GO analysis of DE-TFs was enriched in the DNA binding. Protein-protein interaction network (PPI) found 12 hubs, including SMAD4, SMAD2, SMAD3, SP1, GATA2, NR3C1, PPARG, FOXO1, MEF2A, NCOA2, LEF1, and ETS1, which verified genes expression levels by real-time PCR. Conclusions In this study, SMAD2, PPARG, LEF1, ETS1, GATA2, MEF2A, and NCOA2 are potential candidates that could be targeted by Sr to mediate cell proliferation and differentiation, as well as lipid metabolism. Hence, these results enhance the comprehension of Sr in the regulation of transcription factors and provide new insight into the study of Sr biological function in ruminant animals.

Two methods of using permanent NdFeB magnets and their impact on the sorption of radionuclides (Cs, Sr, Co) by clinoptilolite and composite sorbents based on zeolites are discussed. Sorption processes were considered under dynamic conditions with liquid circulation. No changes in sorption processes were observed when magnetic treatment was applied to solutions containing radionuclide ions. The natural zeolite clinoptilolite and synthetic zeolites NaX and NaA were considered at this stage. In the work, clinoptilolite from the Sokirnitske deposit in the Zakarpattia region of Ukraine was used. Ukraine possesses significant deposits of clinoptilolite. When magnets were applied to the sorbent during the sorption process, an increase in cobalt sorption of 10% was observed for clinoptilolite, and strontium sorption increased by 17%. The influence of a magnet on clinoptilolite is due to the presence of iron ions in the composition of clinoptilolite. The iron content ranges from 0.9% to 2.5%. The composition of the composite sorbent included clinoptilolite and synthetic zeolite NaX. No increase in radionuclide sorption was observed for composite sorbents, likely due to the presence of clinoptilolite in the sorbent composition and the corresponding iron content. The analytical part of the study was carried out using the PIXE (Particle Induced X-ray Emission) method on the analytical nuclear-physics complex "Sokil." The energy range of the accelerator was 200-2000 keV. The complex made it possible to carry out all the main methods of analysis using ion beams. The targets were placed in the exit, at the Chamber for PIXE. To excite the atoms of cesium, strontium, and cobalt a proton beam with an energy of Ер≈1400 keV was used.

We systematically studied the magneto-resistance of strontium (Sr) doped topological insulator (TI) Bi 2 Se 3 films. For Bi 2 Se 3 films with relatively large classic magneto-resistance, we found that slightly Sr doping can completely suppress the classic magneto-resistance and make the weak antilocalization effect dominate in the weak-magnetic-field region. Consequently, the value of the magneto-resistance is enhanced by more than 2.7 times at 0.2 T in slightly doped samples. In contrast, in the strong-magnetic-field region, the magneto-resistance is strongly reduced by doping but exhibits linear magneto-resistance behavior. Our results suggest that the linear magneto-resistance behavior originates from the mobility fluctuation induced by disorder described by the Parish–Littlewood model. Our findings not only gain insights into the doping effect on the topological insulator but also provide an effective way to manipulate the magneto-transport properties of TI for potential applications in future. [ABSTRACT FROM AUTHOR]

We report the production and spectroscopic characterization of strontium(I) phenoxide (SrOC6H5 or SrOPh) and variants featuring electron-withdrawing groups designed to suppress vibrational excitation during spontaneous emission from the electronically excited state. Optical cycling closure of these species, which is the decoupling of the vibrational state changes from spontaneous optical decay, is found by dispersed laser-induced fluorescence spectroscopy to be high, in accordance with theoretical predictions. A high-resolution, rotationally resolved laser excitation spectrum is recorded for SrOPh, allowing the estimation of spectroscopic constants and identification of candidate optical cycling transitions for future work. The results confirm the promise of strontium phenoxides for laser cooling and quantum state detection at the single-molecule level.