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This study undertook a comprehensive examination of the double perovskite complex Ba 2 FeWO 6 , investigating its structural, electrical, magnetic, thermal and elastic characteristics. The study used density functional theory (DFT), specifically the full potential linearized augmented plane wave (FP-LAPW) method. It also used different approximations, including the generalized gradient approximation (GGA) and the modified Trans-Blaha (TB-mBJ) approach, to improve the accuracy of the band gap estimation more accurate. Additionlly, the GGA + U approach, incorporating the Hubbard correction term (U), was utilized. Our findings indicate that Ba 2 FeWO 6 exhibits indirect half-metallic band gaps in the (L-X) direction, with value of 0.91 eV and a net magnetic moment of 4 μ B , predominatly influenced by the iron atom. The compound demonstrated exceptional characteristics suitable for thermoelectric applications, particularly at lower temperatures. Furthermore, the elasticity analysis revealed low brittleness, facilitates its manipulation in manufacturing procedures., Competing Interests: Declaration of competing interest The research, authorship, and publication of this article did not involve any external funding. The research was conducted in the course of the authors' routine responsibilities., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective. The objective of this study is to explore the capabilities of photon-counting computed tomography (PCCT) in simultaneously imaging and differentiating materials with close atomic numbers, specifically barium ( Z = 56) and iodine ( Z = 53), which is challenging for conventional computed tomography (CT). Approach. Experiments were conducted using a bench-top PCCT system equipped with a cadmium zinc telluride detector. Various phantom setups and contrast agent concentrations (1%-5%) were employed, along with a biological sample. Energy thresholds were tuned to the K-edge absorption energies of barium (37.4 keV) and iodine (33.2 keV) to capture multi-energy CT images. K-edge decomposition was performed using K-edge subtraction and principal component analysis (PCA) techniques to differentiate and quantify the contrast agents. Main results. The PCCT system successfully differentiated and accurately quantified barium and iodine in both phantom combinations and a biological sample, achieving high correlations (R2≈1) between true and reconstructed concentrations. PCA outperformed K-edge subtraction, particularly in the presence of calcium, by providing superior differentiation between barium and iodine. Significance. This study demonstrates the potential of PCCT for reliable, detailed imaging in both clinical and research settings, particularly for contrast agents with similar atomic numbers. The results suggest that PCCT could offer significant improvements in imaging quality over conventional CT, especially in applications requiring precise material differentiation., (Creative Commons Attribution license.)

This study investigates the co-precipitation of calcium and barium ions in hypersaline wastewater under the action of Bacillus licheniformis using microbially induced carbonate precipitation (MICP) technology, as well as the bactericidal properties of the biomineralized product vaterite. The changes in carbonic anhydrase activity, pH, carbonate and bicarbonate concentrations in different biomineralization systems were negatively correlated with variations in metal ion concentrations, while the changes in polysaccharides and protein contents in bacterial extracellular polymers were positively correlated with variations in barium concentrations. In the mixed calcium and barium systems, the harvested minerals were vaterite containing barium. The increasing concentrations of calcium promoted the incorporation and adsorption of barium onto vaterite. The presence of barium significantly increased the contents of O-CO, N-CO, and Ba-O in vaterite. Calcium promoted barium precipitation, but barium inhibited calcium precipitation. After being treated by immobilized bacteria, the concentrations of calcium and barium ions decreased from 400 and 274 to 1.72 and 0 mg/L (GB/T15454-2009 and GB8978-1996). Intracellular minerals were also vaterite containing barium. Extracellular vaterite exhibited bactericidal properties. This research presents a promising technique for simultaneously removing and recycling hazardous heavy metals and calcium in hypersaline wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Microalgae immobilization in alginate beads shows promise for biomass production and water pollution control. However, carrier instability and mass transfer limitations are challenges. This study introduces buoyant barium alginate bubble beads (BABB), which offer exceptional stability and enhance Chlorella vulgaris growth. In just 12 days, compared to traditional calcium alginate beads, BABB achieved a 20 % biomass increase while minimizing cell leakage and simplifying harvesting. BABB optimization involved co-immobilization with BG-11 medium, enrichment of CO 2 in internal bubbles, and the integration of Fe nanoparticles (FeNPs). In the open raceway pond reactor, these optimizations resulted in a 39 % increase in biomass over 7 days compared to the unoptimized setup in closed flasks. Furthermore, enhancements in pigment and organic matter production were observed, along with improved removal of ammonia nitrogen and phosphate. These results highlight the overall advantages of BABB for microalgae immobilization, offering a scientific foundation for their effective utilization., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Chemical oxo-precipitation (COP) is an enhanced precipitation method for boron removal with the conversion of boric acid to perborate anions. When using barium-based precipitant, the boron can be effectively precipitated as barium perborates (BaPBs). The phase transformation of BaPBs from amorphous (A-BaPB, Ba(B(OH) 3 OOH) 2 ) to crystalline (C-BaPB, BaB 2 (OO) 2 (OH) 4 ) form is crucial for effective boron removal. However, scaling up this phase transformation of BaPBs is hindered by poor diffusion. This study aims to promote the growth of C-BaPB through seed-induced crystal growth, eliminating the need for phase transformation. By examining the relationship between crystal growth rate and supersaturation, surface spiral growth was identified as the rate-limiting step of the growth of micron-sized seeds near pH pzc . To enable continuous crystal growth, granular seeds of C-BaPB were prepared and employed as the medium for fluidized-bed crystallization (FBC). The system reached steady state 3 hydraulic retention times, achieving 90% boron removal. The effect of surface loading, ionic strength, and dosages on steady-state crystal growth rate was studied, revealing a shift of the rate-limiting step in FBC to diffusion. Lastly, the system that constituted of two FBCs in-series for sequential crystallization of A-BaPB and C-BaPB was demonstrated. The integrated system provided 97.8% of boron removal from synthetic wastewater containing 500 mg-B/L, with 92.3% of boron crystallized on the granular seeds of BaPBs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The near-infrared (NIR) down-conversion process for broadband sensitization has been studied in Eu 2+ -Nd 3+ co-doped BaAl 2 O 4 . This material has a broad absorption band of 200-480 nm and can convert photons in the visible region into NIR photons. The NIR emission at 1064 nm, attributed to the Nd 3+ : 4 F 3/2  →  4 I 11/2 transition, matches the bandgap of Si, allowing Si solar cells to utilize the solar spectrum better. The energy transfer (ET) process between Eu 2+ and Nd 3+ was demonstrated using photoluminescence spectra and luminescence decay curves, and Eu 2+ may transfer energy to Nd 3+ through the cooperative energy transfer (CET) to achieve the down-conversion process. The energy transfer efficiency (ETE) and theoretical quantum efficiency (QE) were 68.61% and 156.34%, respectively, when 4 mol% Nd 3+ was introduced. The results indicate that BaAl 2 O 4 :Eu 2+ -Nd 3+ can serve as a potential modulator of the solar spectrum and is expected to be applied to Si solar cells., (© 2024 John Wiley & Sons Ltd.)

Most of the state-of-the-art thermoelectric materials are inorganic semiconductors. Owing to the directional covalent bonding, they usually show limited plasticity at room temperature 1,2 , for example, with a tensile strain of less than five per cent. Here we discover that single-crystalline Mg 3 Bi 2 shows a room-temperature tensile strain of up to 100 per cent when the tension is applied along the (0001) plane (that is, the ab plane). Such a value is at least one order of magnitude higher than that of traditional thermoelectric materials and outperforms many metals that crystallize in a similar structure. Experimentally, slip bands and dislocations are identified in the deformed Mg 3 Bi 2 , indicating the gliding of dislocations as the microscopic mechanism of plastic deformation. Analysis of chemical bonding reveals multiple planes with low slipping barrier energy, suggesting the existence of several slip systems in Mg 3 Bi 2 . In addition, continuous dynamic bonding during the slipping process prevents the cleavage of the atomic plane, thus sustaining a large plastic deformation. Importantly, the tellurium-doped single-crystalline Mg 3 Bi 2 shows a power factor of about 55 microwatts per centimetre per kelvin squared and a figure of merit of about 0.65 at room temperature along the ab plane, which outperforms the existing ductile thermoelectric materials 3,4 ., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

The clinical success of [ 223 Ra]RaCl 2 (Xofigo®) for the palliative treatment of bone metastases in patients with prostate cancer has highlighted the therapeutic potential of α-particle emission. Expanding the applicability of radium-223 in Targeted Alpha Therapy of non-osseous tumors is followed up with significant interest, as it holds the potential to unveil novel treatment options in the comprehensive management of cancer. Moreover, the use of barium radionuclides, like barium-131 and -135m, is still unfamiliar in nuclear medicine applications, although they can be considered as radium-223 surrogates for imaging purposes. Enabling these applications requires the establishment of chelators able to form stable complexes with radium and barium radionuclides. Until now, only a limited number of ligands have been suggested and these molecules have been primarily inspired by existing structures known for their ability to complex large metal cations. However, a systematic inspection of chelators specifically tailored to Ra 2+ and Ba 2+ has yet to be conducted. This work delves into a comprehensive investigation of a series of small organic ligands, aiming to unveil the coordination preferences of both radium-223 and barium-131/135m. Electronic binding energies of both metal cations to each ligand were theoretically computed via Density Functional Theory calculations (COSMO-ZORA-PBE-D3/TZ2P), while thermodynamic stability constants were experimentally determined for Ba 2+ -ligand complexes by potentiometry, NMR and UV-Vis spectroscopies. The outcomes revealed malonate, 2-hydroxypyridine 1-oxide and picolinate as the most favorable building blocks to design multidentate chelators. These findings serve as foundation guidelines, propelling the development of cutting-edge radium-223- and barium-131/135m-based radiopharmaceuticals for Targeted Alpha Therapy and theranostics of cancer., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The structural integrity, assembly yield, and biostability of DNA nanostructures are influenced by the metal ions used to construct them. Although high (>10 mM) concentrations of divalent ions are often preferred for assembling DNA nanostructures, the range of ion concentrations and the composition of the assembly products vary for different assembly conditions. Here, we examined the unique ability of Ba 2+ to retard double crossover DNA motifs by forming a low mobility species, whose mobility on the gel is determined by the concentration ratio of DNA and Ba 2+ . The formation of this electrophoretically retarded species is promoted by divalent ions such as Mg 2+ , Ca 2+ , and Sr 2+ when combined with Ba 2+ but not on their own, while monovalent ions such as Na + , K + , and Li + do not have any effect on this phenomenon. Our results highlight the complex interplay between the metal ions and DNA self-assembly and could inform the design of DNA nanostructures for applications that expose them to multiple ions at high concentrations.

The design and synthesis of nano- and microcarriers for preclinical and clinical imaging are highly attractive due to their unique features, for example, multimodal properties. However, broad translation of these carriers into clinical practice is postponed due to the unknown biological reactivity of the new components used for their synthesis. Here, we have developed microcarriers (∼2-3 μ m) and  nanocarriers (<200 nm) made of barium carbonate (BaCO 3 ) for multiple imaging applications in vivo . In general, barium in the developed carriers can be used for X-ray computed tomography, and the introduction of a diagnostic isotope ( 99m Tc) into the BaCO 3 structure enables in vivo visualization using single-photon emission computed tomography. The bioimaging has shown that the radiolabeled BaCO 3 nano- and microcarriers had different biodistribution profiles and tumor accumulation efficiencies after intratumoral and intravenous injections. In particular, in the case of intratumoral injection, all the types of used carriers mostly remained in the tumors (>97%). For intravenous injection, BaCO 3 microcarriers were mainly localized in the lung tissues. However, BaCO 3 NPs were mainly accumulated in the liver. These results were supported by ex vivo fluorescence imaging, direct radiometry, and histological analysis. The BaCO 3 -based micro- and nanocarriers showed negligible in vivo toxicity towards major organs such as the heart, lungs, liver, kidneys, and spleen. This study provides a simple strategy for the design and fabrication of the BaCO 3 -based carriers for the development of dual bioimaging.

In the crystals of alkaline earth metal compounds strontium and barium with the non-steroidal anti-inflammatory drug nimesulide, the strontium cation is nine-coordinated with a distorted tricapped trigonal prismatic geometry TCTPR-9, whereas the ten-coordinated barium ion exhibits a distorted tetracapped trigonal prismatic geometry TCTPR-10.

The piezoelectric effect is widely known to have a significant physiological function in bone development, remodeling, and fracture repair. As a well-known piezoelectric material, barium titanate is particularly appealing as a scaffold layer to improve bone tissue engineering applications. Currently, the chemical bath deposition method is used to prepare green synthesized barium titanate coatings to improve mechanical and biological characteristics. Molarity of the solutions, an essential parameter in chemical synthesis, is changed at room temperature (0.1-1.2 Molar) to prepare coatings. The XRD spectra for as deposited coatings indicate amorphous behavior, while polycrystalline nature of coatings is observed after annealing (300 °C). Coatings prepared with solutions of relatively low molarities, i.e. from 0.1 to 0.8 M, exhibit mixed tetragonal - cubic phases. However, the tetragonal phase of Perovskite barium titanate is observed using solution molarities of 1.0 M and 1.2 M. Relatively high value of transmission, i.e. ∼80%, is observed for the coatings prepared with high molarities. Band gap of annealed coatings varies between 3.47 and 3.70 eV. For 1.2 M sample, the maximum spontaneous polarization (P s ) is 0.327x10 -3 (μC/cm 2 ) and the residual polarization (P r ) is 0.072x10 -3 (μC/cm 2 ). For 1.2M solution, a high hardness value (1510 HV) is recorded, with a fracture toughness of 28.80 MPam -1/2 . Low values of weight loss, after dipping the coatings in simulated body fluid, is observed. The antibacterial activity of BaTiO 3 is tested against E. coli and Bacillus subtilis. Drug encapsulation capability is also tested for different time intervals. As a result, CBD-based coatings are a promising nominee for use as scaffold and protective coatings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

A series of tellurite-based glasses are prepared by using a melt-quenching method. The effect of cerium on the physical, thermal, structural, optical, spectroscopic, and shielding properties of barium tellurite glass samples is studied. It has been observed that the thermal stability factor increases with increasing cerium ion (Ce 3+ ) concentration. The density and other physical parameters such as ion concentration and molar volume are calculated using the Archimedes principle. An increase in optical band gap and density suggests a decrement in non-bridging oxygens. These results are in accordance with Raman results. The blue emission in prepared glasses is studied in terms of International Commission on Illumination chromaticity coordinates. Moreover, various shielding properties such as mass attenuation coefficient, linear attenuation coefficient, effective atomic number, half-value layer, and tenth-value layer have also been determined to understand the photon shielding characteristics of as-prepared glass samples., (© 2023 John Wiley & Sons Ltd.)

By conducting binding experiments at a range of temperatures T using isothermal titration calorimetry (ITC), one can obtain two estimates of the binding enthalpy - calorimetric (ΔH° cal ) from the experiments at each T, and van't Hoff (ΔH° vH ) from the T dependence of the binding constant K°. From thermodynamics it is clear that these two must be identical, but early efforts to demonstrate this for ITC data indicated significant inconsistency. In an extensive 2004 study of the Ba 2+ + 18-crown-6 ether complexation used in prior comparisons, Mizoue and Tellinghuisen found modest (10-20%) but statistically significant differences, which were tentatively attributed to problems converting the calorimetric estimates to their standard state values, as implied by the superscript ° in the notation. In the present work the 2004 results are reanalyzed using results obtained since then from temperature, heat, and volume calibration of the instrument and a better determination of the data variance function required for the weighted least-squares fitting of the data. The new results show consistency for temperatures 5-30 °C but persistent statistically significant differences from 35 to 46 °C. Several possible explanations for the remaining discrepancies are examined, with methods that include fitting the K and ΔH cal data together., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This study used substituted barium hexaferrites, which were previously prepared and reported by the authors, to detect acetaminophen by the modification of a conventional glassy carbon electrode (GCE), which led to promising results. The synthesis of this electrode-modifying material was conducted using a citrate sol gel process. A test synthesis using glycerin and propylene glycol revealed that glycerin produced a better result, while less positive anodic potential values were associated with the electrooxidation of N-acetyl-p-aminophenol (NAP). Excellent electroactivity was exhibited by the cobalt-substituted barium-hexaferrite-nanomaterial-modified electrode. A good linear relationship between the concentration and the current response of acetaminophen (paracetamol) was obtained with a detection limit of (0.255 ± 0.005) µM for the Ba 1.0 Co 1.22 Fe 11.41 O 18.11 GCE, (0.577 ± 0.007) µM for the Ba 1.14 Cu 0.82 Fe 11.65 O 18.02 GCE, and (0.595 ± 0.008) µM for the bare GCE. The levels of NAP in a real sample of urine were quantitatively analyzed using the proposed method, with recovery ranges from 96.6% to 101.0% and 93.9% to 98.4% for the modified electrode with Cobalt-substituted barium hexaferrites (CoF M ) and Copper-substituted barium hexaferrites (CuF M ), respectively. These results confirm the high electrochemical activity of Ba 1.0 Co 1.22 Fe 11.41 O 18.11 nanoparticles and thus their potential for use in the development of sensing devices for substances of pharmaceutical interest, such as acetaminophen (NAP).

Trivalent europium-based monochromatic red light-emitting phosphors are an essential component to realize high-performance smart lighting devices; however, the concentration and thermal quenching restrict their usage. Here, we report a series of efficient Eu 3+ -substituted Li 3 Y 3 BaSr(MoO 4 ) 8 red-emitting phosphors based on a stratified scheelite structure with negligible concentration and thermal quenching. All of the host and phosphor compositions crystallize in monoclinic crystal structure (space group C 2/ c ). All of the phosphor compositions produce narrow-band red emission (FWHM ∼6 nm), which is highly apparent to the human eyes, and lead to exceptional chromatic saturation of the red spectral window. Concurrently, detailed investigations were carried out to comprehend the concentration and thermal quenching mechanism. Absolute quantum yields as high as 88.5% were obtained for Li 3 Y 0.3 Eu 2.7 BaSr(MoO 4 ) 8 phosphor with virtuous thermal stability (at 400 K, retaining 87% of its emission intensity). The light-emitting diodes were constructed by coupling Li 3 BaSrY 0.3 Eu 2.7 (MoO 4 ) 8 red phosphor with a near-UV LED chip (395 nm) operated at 20 mA forward bias, and the hybrid white LED (an organic yellow dye + red Li 3 Y 3 BaSr(MoO 4 ) 8 :Eu 3+ phosphor integrated with an NUV LED chip) showed a low CCT (6645 K), high CRI (83) values, and CIE values of x = 0.303; y = 0.368, which indicated that the synthesized phosphors can be a suitable red component for white LEDs. In addition, we have systematically investigated the Sm 3+ and Sm 3+ , Eu 3+ activation in Li 3 Y 3 BaSr(MoO 4 ) 8 to display the latent use of the system in plant growth applications and establish that the phosphor exhibits orange red emission with an intense deep-red emission (645 nm ( 4 G 5/2 → 6 H 9/2 )). The phytochrome (Pr) absorption spectrum well matched the fabricated deep-red LED (by integrating a NUV LED + Li 3 Y 3 BaSr(MoO 4 ) 8 :Sm 3+ and Eu 3+ phosphor) spectral lines.

Cadmium (Cd) as a toxic element that is widely present in water, soil, and air has important effects on human health, therefore proposing an accurate and selective method for detection of this element is of importance. In this article, by employing full atomistic molecular dynamics (MD) simulations and density functional theory dispersion corrected (DFT-D3) calculations, the effects of 6-mercaptonicotinic acid (MNA) and L-cysteine (CYS) on the stability of gold nanoparticles (AuNPs) and their sensitivity against Cd 2+ were investigated. The obtained results indicate that pure AuNPs are not stable in water, while functionalized AuNPs with CYS and MNA groups have considerable stability without aggregation. In other words, the functional groups on the surface of AuNPs elevate their resistance against aggregation by an increase in the repulsive interactions between the gold nanoparticles. Moreover, functionalized AuNPs have considerable ability for selective detection of Cd 2+ in the presence of different metal ions. Based on the MD simulation results, MNA-CYS-AuNPs (functionalized AuNPs with both functional groups) have the maximum sensitivity against Cd 2+ in comparison with MNA-AuNPs and CYS-AuNPs due to the strong electrostatic interactions. DFT-D3 calculations reveal that the most probable interactions between the metal ions and functional groups are electrostatic, and Cd 2+ can aggregate functionalized AuNPs due to strong electrostatic interactions with MNA and CYS groups. Moreover, charge transfer and donor-acceptor analyses show that molecular orbital interactions between the functional groups and Cd 2+ can be considered as the driving force for AuNPs aggregation. A good agreement between the theoretical results and experimental data confirms the importance of the molecular modeling methods as a fast scientific protocol for designing new functionalized nanoparticles for application in different fields., (© 2021. The Author(s).)

X-ray photodynamic therapy (XPDT) has been recently considered as an efficient alternative to conventional radiotherapy of malignant tissues. Nanocomposites for XPDT typically consist of two components-a nanophosphor which re-emits X-rays into visible light that in turn is absorbed by the second component, a photosensitizer, for further generation of reactive oxygen species. In this study, BaGdF 5 nanophosphors doped with different Eu:Gd ratios in the range from 0.01 to 0.50 were synthesized by the microwave route. According to transmission electron microscopy (TEM), the average size of nanophosphors was ~12 nm. Furthermore, different coatings with amorphous SiO 2 and citrates were systematically studied. Micro-CT imaging demonstrated superior X-ray attenuation and sufficient contrast in the liver and the spleen after intravenous injection of citric acid-coated nanoparticles. In case of the SiO 2 surface, post-treatment core-shell morphology was verified via TEM and the possibility of tunable shell size was reported. Nitrogen adsorption/desorption analysis revealed mesoporous SiO 2 formation characterized by the slit-shaped type of pores that should be accessible for methylene blue photosensitizer molecules. It was shown that SiO 2 coating subsequently facilitates methylene blue conjugation and results in the formation of the BaGdF 5 : 10% Eu 3+ @SiO 2 @MB nanocomposite as a promising candidate for application in XPDT.

Hydroxyapatite (HA) is the most commonly used orthopedic implant material. In recent years, the emergence of cationic doped hydroxyapatite has revealed more possibilities for the biological application of HA. Conventional HA does not promote new bone formation because of its poor osteoinductive activity, and has a similar density to that of bone, leading to difficulty in distinguishing both via imaging. Magnesium ions are useful for regulating the cellular behavior and promoting bone regeneration. Ba ion related compounds, such as BaSO 4 , have a strong X-ray shielding effect. In this study, Ba/Mg@HA was synthesized to prepare Ba/Mg@HA/PLGA composites, and we aimed to investigate if Ba/Mg@HA/PLGA composites enhanced bone repair on osteoblasts and tibial defects, as well as the X-ray and CT imaging ability of bone implants in rats. The in vitro experimental results showed that the Ba/Mg@HA/PLGA composites significantly improved the attachment and osteogenic differentiation of MC3T3-E1 cells. These include the promotion of mineral deposition, enhancement of alkaline phosphatase activity, upregulation of OCN and COL-1 gene expression, and increase in COL-1 and OCN protein expression in a time- and concentration-dependent manner. The in vivo experimental results showed that the Ba/Mg@HA/PLGA composites significantly increased the rate of bone defect healing and the expression of BMP-2 and COL-1 in the bones of rats. X-ray and CT imaging results showed that the Ba/Mg@HA/PLGA composites enhanced the X-ray imaging ability. These findings indicate that the Ba/Mg@HA/PLGA composites can effectively promote bone formation and improve the X-ray and CT imaging abilities to a certain extent.

The aim of this study was cost-effective and greener synthesis of barium carbonate (BaCO 3 or witherite) nanoparticles with economic importance, and to evaluate their therapeutic potentials and biocompatibility with immune cells. Barium carbonate nanoparticles were biosynthesized using black elderberry extract in one step with non-toxic precursors and simple laboratory conditions; their morphologies and specific structures were analyzed using field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The therapeutic capabilities of these nanoparticles on the immune cells of murine macrophages J774 and promastigotes Leishmania tropica were evaluated. BaCO 3 nanoparticles with IC 50  = 46.6 µg/mL were more effective than negative control and glucantium (positive control) in reducing promastigotes (P < 0.01). Additionally, these nanoparticles with a high value of cytotoxicity concentration 50% (CC 50 ) were less toxic to macrophage cells than glucantime; however, they were significantly different at high concentrations compared to the negative control., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This research paper is concentrated on the design of biologically compatible lead-free piezoelectric composites which may eventually replace traditional lead zirconium titanate (PZT) in micromechanical fluidics, the predominantly used ferroelectric material today. Thus, a lead-free barium-calcium zirconate titanate (BCZT) composite was synthesized, its crystalline structure and size, surface morphology, chemical, and piezoelectric properties were analyzed, together with the investigations done in variation of composite thin film thickness and its effect on the element properties. Four elements with different thicknesses of BCZT layers were fabricated and investigated in order to design a functional acoustophoresis micromechanical fluidic element, based on bulk acoustic generation for particle control technologies. Main methods used in this research were as follows: FTIR and XRD for evaluation of chemical and phase composition; SEM-for surface morphology; wettability measurements were used for surface free energy evaluation; a laser triangular sensing system-for evaluation of piezoelectric properties. XRD results allowed calculating the average crystallite size, which was 65.68 Å 3 confirming the formation of BCZT nanoparticles. SEM micrographs results showed that BCZT thin films have some porosities on the surface with grain size ranging from 0.2 to 7.2 µm. Measurements of wettability showed that thin film surfaces are partially wetting and hydrophilic, with high degree of wettability and strong solid/liquid interactions for liquids. The critical surface tension was calculated in the range from 20.05 to 27.20 mN/m. Finally, investigations of piezoelectric properties showed significant results of lead-free piezoelectric composite, i.e., under 5 N force impulse thin films generated from 76 mV up to 782 mV voltages. Moreover, an experimental analysis showed that a designed lead-free BCZT element creates bulk acoustic waves and allows manipulating bio particles in this fluidic system.

This study investigates combining the good biocompatibility and flexibility of silk protein with three types of widely used magnetic nanoparticles to comparatively explore their structures, properties and potential applications in the sustainability and biomaterial fields. The secondary structure of silk protein was quantitatively studied by infrared spectroscopy. It was found that magnetite (Fe 3 O 4 ) and barium hexaferrite (BaFe 12 O 19 ) can prohibit β-sheet crystal due to strong coordination bonding between Fe 3+ ions and carboxylate ions on silk fibroin chains where cobalt particles showed minimal effect. This was confirmed by thermal analysis, where a high temperature degradation peak was found above 640 °C in both Fe 3 O 4 and BaFe 12 O 19 samples. This was consistent with the magnetization studies that indicated that part of the Fe in the Fe 3 O 4 and BaFe 12 O 19 was no longer magnetic in the composite, presumably forming new phases. All three types of magnetic composites films maintained high magnetization, showing potential applications in MRI imaging, tissue regeneration, magnetic hyperthermia and controlled drug delivery in the future.

Recently, the iron containing langasite-type crystal Ba 3 NbFe 3 Si 2 O 14 has attracted great attention as a new magnetically induced multiferroic. In this work, magnetic, structural and electronic properties of the multiferroic Ba 3 NbFe 3 Si 2 O 14 were investigated by several methods, including synchrotron X-ray diffraction, Raman spectroscopy and synchrotron Mössbauer source technique at high quasi-hydrostatic pressures (up to 70 GPa), created in diamond anvil cells. At room temperature, two structural transitions at pressures of about 3.0 and 17.5 GPa were detected. Mössbauer studies at high pressures revealed a radical change in the magnetic properties during structural transitions. At pressures above 18 GPa, the crystal transforms into two magnetic fractions, and in one of them the Néel temperature ( T N ) increases by about four times compared with the T N value in the initial phase (from 27 to 115 K). At pressures above 50 GPa, a spin crossover occurs when the fraction of iron Fe 3+ ions in oxygen octahedra transits from the high-spin ( HS , S = 5/2) to the low-spin ( LS , S = 1/2) state. This leads to a new change in the magnetic properties. The magnetic ordering temperature of the LS sublattice was found to be of about 22(1) K, and magnetic correlations between HS and LS sublattices were studied.

Barium (Ba 2+ ) is a classic permeant blocker of potassium (K + ) channels. The "external lock-in effect" in barium block experiments, whereby the binding of external K + impedes the forward translocation of the blocker, provides a powerful avenue to investigate the selectivity of the binding sites along the pore of potassium channels. Barium block experiments show that the external lock-in site is highly selective for K + over Na + . Wild-type KcsA was crystallized in low K + conditions, and the crystals were soaked in solutions containing various concentrations of barium. Structural analysis reveals open and closed gate conformations of the KcsA channel. Anomalous diffraction experiments show that Ba 2+ primarily binds to the innermost site S4 of the selectivity filter of the open-gate conformation and also the site S2, but no binding is detected with the closed-gate conformation. Alchemical free-energy perturbation calculations indicate that the presence of a Ba 2+ ion in the selectivity filter boosts the specificity of K + binding relative to Na + in the external sites S0-S2., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this paper, BaY 2 O 4 :Yb 3+ /Er 3+ , a high efficient red upconversion (UC) material, is first utilized as an optical thermometer in the biological window, accomplished through the fluorescence intensity ratio (FIR) of thermally coupled Stark sublevels of 4 F 9/2 (FIR (654/663) ). The maximum absolute sensitivity of FIR (654/663) ) is 0.19% K -1 at 298 K, which is much higher than most previous reports about FIR-based temperature sensors located in the biological windows. More importantly, the groove of FIR (654/663) for thermometry is nicely located in the physiological temperature range, indicating its potential thermometry application value in biomedicine. Furthermore, a simply ex vivo experiment is implemented to evaluate the penetration depth of the red emission in biological tissues, revealing that a detection depth of 6 mm can be achieved without any effect on the FIR values of I 654 to I 663 . Beyond that, the temperature sensing behaviors of the thermally coupled levels 2 H 11/2 and 4 S 3/2 (FIR (523/550) ) are also investigated in detail. In the studied temperature range, the absolute sensitivity of FIR (523/550) monotonously increases with the rising temperature and reaches its maximum value 0.31% K -1 at 573 K. All the results imply that BaY 2 O 4 :Yb 3+ /Er 3+ is a promising candidate for deep-tissue optical thermometry with high sensitivity.

High-Z nanoparticles have emerged as a novel type of radiosensitizers due to their relatively large X-ray cross-section and ability to enhance radical production under irradiation. Recently, CaWO 4 nanoparticles have been prepared and their potential as a radiosensitizer has been demonstrated. Herein, we investigated BaWO 4 nanoparticles as a novel type of alkaline-earth metal tungstate radiosensitizer for radiotherapy (RT). We synthesized BaWO 4 nanoparticles using hydrothermal reaction and coated them with polyvinylpyrrolidone (PVP). We found that BaWO 4 nanoparticles could more efficiently enhance hydroxyl radical production under irradiation than CaWO 4 nanoparticles. When tested in vitro, BaWO 4 nanoparticles showed lower toxicity than CaWO 4 nanoparticles in the absence of irradiation, but induced more significant oxidative stress under irradiation. When tested in vivo, BaWO 4 nanoparticles led to more efficient tumor inhibition without causing systemic toxicity. Overall, our results suggest that BaWO 4 nanoparticles can efficiently enhance RT and hold great potential as a novel type of radiosensitizing agent., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this paper, we have reported the photoluminescence (PL) properties of the Ba 2 Mg(PO 4 ) 2 :Eu 3+ phosphor synthesized using a wet chemical method. The preliminary scanning electron microscopy (SEM) investigation of the sample revealed irregular surface morphology with particle sizes in the 10-50 μm range. The strongest PL excitation peak was observed at 396 nm. The emission spectra indicated that this phosphor can be effectively excited by the 396 nm wavelength. Upon 396 nm excitation, the emission spectrum showed characteristics peaks located at 592 nm and 615 nm. These intense orange-red emission peaks were obtained due to f→f transitions of Eu 3+ ions. The emission peak at 592 nm is referred to as the magnetic dipole 5 D 0 → 7 F 1 transition and the emission peak at 615 nm corresponded to the electric dipole 5 D 0 → 7 F 2 transition of Eu 3+ . The Commission Internationale de l'Eclairage (CIE) coordinates of the Ba 2 Mg(PO 4 ) 2 :Eu 3+ phosphor were found to be (0.586, 0.412) for wavelength 592 nm and (0.680, 0.319) for wavelength 615 nm situated at the edge of the CIE diagram, indicating high colour purity of phosphors. Due to the high emission intensity and a good excitation profile, Eu 3+ -doped Ba 2 Mg(PO 4 ) 2 phosphor may be a promising orange-red phosphor candidate for solid-state lighting applications., (© 2019 John Wiley & Sons, Ltd.)

Simple and direct determination of sulfate ion concentrations has many important applications, such as analysis of sulfohydrolase activities in biological fluids. Unfortunately, a reported barium-rhodizonate spectrophotometric method with many advantages faces a solubility challenge. To overcome this problem, solvation of rhodizonate complexes in its metathesis reaction was systematically investigated by 46 solvents/compounds using curvilinear regression methods to fit sulfate calibration intervals for signal linearity and color stability. The results revealed solvent structure-activity relationships to the color formation and provided optimal solvent formulae that enable this colorimetry in the stoichiometric way. The limit of water content in the colorimetric matrix increased from 20 to 45% and color formed for reading was stable for 45-135 min. The rhodizonate reagents were stable at -70 °C for >6 months. This established the robustness of the assay, which can now measure the sulfate ion concentration at 0.18 nmol, in comparison to 1 nmol of the early reports. The method provides a simple and direct analysis of sulfate ion, suitable for kinetics studies of sulfohydrolase activity in biological fluids., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A gene encoding the enzyme trehalose-6-phosphate synthase (TPS), which is part of the TPS trehalose synthesis pathway, was cloned from the deep-sea psychrotolerant bacterium Microbacterium sediminis YLB-01 and expressed in Escherichia coli BL21. The exogenously expressed TPS exhibited highest similarity (80.93% identity) to Microbacterium sp. TPS. The purified recombinant TPS was cold-tolerant, with low thermostability. The optimum temperature for TPS activity was 40°C, and the enzyme retained 72.6% of its maximal activity at 4°C. The optimum pH was 7.5. TPS activity was cation-dependent, with Mg 2+ , Co 2+ , or Ba 2+ being essential for maximum activity. The kinetic constants of the recombinant TPS reaction rates confirmed that it was cold-tolerant. Molecular dynamics analysis showed that TPS was more flexible (0.8741Å) at 4°C than 1GZ5, its homolog in the mesophilic bacterium E. coli , and superposition of the 3D enzyme structures supported this.

Total joint replacement implants are generally designed to physically mimic the biological environment to ensure compatibility with the host tissue. However, implant instability exposes patients to long recovery periods, high risk for revision surgeries, and high expenses. Introducing electrical stimulation to the implant site to accelerate healing is promising, but the cumbersome nature of wired devices is detrimental to the implant design. We propose a novel strategy to stimulate cells at the implant site by utilizing piezoelectric ceramics as electrical stimulation sources. The inherent ability of these materials to form electric surface potentials under mechanical load allows them to act as internal power sources. This characteristic is commonly exploited in non-biomedical applications such as transducers or sensors. We investigate calcium/zirconium-doped barium titanate (BCZT) ceramics in an in vitro environment to determine their potential as implant materials. BCZT exhibits low cytotoxicity with human osteoblast and endothelial cells as well as high piezoelectric responses. Microstructural adaptation was identified as a route for optimizing piezoelectric behavior. Our results show that BCZT is a promising system for biomedical applications. Its characteristic ability to autonomously generate electric surface potentials opens the possibility to functionalize existing bone replacement implant designs to improve implant ingrowth and long-term stability., (© 2019 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc.)

The development of novel 2D materials, due to the promising applications they have enabled through their unique properties, has attracted increasingly more research interest. In this regard, novel dual-emitting coordination polymer nanosheets were developed by doping Eu 3+ and Tb 3+ ions into the nanostructures of the [Ba(DPA) 2 (H 2 O) 2 ] n (DPA = dipicolinic acid) coordination polymer (BCP). Single crystal x-ray crystallography revealed that BCP is a 1D coordination polymer and its three-dimensional supramolecular architecture is constructed with a relatively strong hydrogen bonding in the ac crystallographic plane and weak non-covalent interactions along the b axis. Using energetic ultrasound irradiations, synthesis of nanoscale BCP along with the unzipping of the weak interactions between the ac layers was accomplished. The resulting BCP nanosheets was used as the host lattice and was doped with Eu 3+ and Tb 3+ ions. Remarkably, the sensing ability of both Eu 3+ and Tb 3+ doped coordination polymer (Ln@BCP) nanosheets towards temperature and the DPA anthrax biomarker were investigate. The high relative sensitivity value of 2.42% K -1 and their reusability, makes Ln@BCP nanosheets an ideal candidate for the nanothermometry. They also exhibited high selective detection characteristics towards the DPA anthrax biomarker with a 0.03 nM detection limit. Therefore, Ln@BCP nanosheets can also be considered as an efficient multi-responsive optical sensor.

Alginate dialdehyde-gelatin (ADA-GEL) hydrogels have been reported to be suitable matrices for cell encapsulation. In general, application of ADA-GEL as bioink has been limited to planar structures due to its low viscosity. In this work, ring shaped constructs of ADA-GEL hydrogel were fabricated by casting the hydrogel into sacrificial molds which were 3D printed from 9% methylcellulose and 5% gelatin. Dissolution of the supporting structure was observed during the 1 st week of sample incubation. In addition, the effect of different crosslinkers (Ba 2+ and Ca 2+ ) on the physicochemical properties of ADA-GEL and on the behavior of encapsulated MG-63 cells was investigated. It was found that Ba 2+ crosslinked network had more than twice higher storage modulus, and mass decrease to 70% during incubation compared to 42% in case of hydrogels crosslinked with Ca 2+ . In addition, faster increase in cell viability during incubation and earlier cell network formation were observed after Ba 2+ crosslinking. No negative effects on cell activity due to the use of sacrificial materials were observed. The approach presented here could be further developed for cell-laden ADA-GEL bioink printing into complex 3D structures.

Polymer surface grafting is widely used in the field of bone regeneration to increase calcium phosphate (CaP) adhesion, with the intent of improving mechanical properties of CaP-polymer composite cements. Reinforcement can be achieved using multiple combined functional groups and/or complex surface geometries that, however, concurrently influence multiple effects such as wetting, roughness, and interfacial strengthening. This study focused on the influence of a chelating group, namely aspartic acid, on the adsorption of divalent ions such as Ba 2+ or Ca 2+ onto poly-l-lactic acid (PLA) films. The films were analyzed using contact angle measurements and X-ray photoelectron spectroscopy. The adsorption of CaP and its interfacial mechanical properties were investigated using functionalized PLA monofilaments whose surface roughness was analyzed using white light interferometry. Mechanical analysis was conducted by performing pull-out tests. The surfaces were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy. Using aspartic acid as a chelating group resulted in a 50 % increased adsorption of barium, an almost threefold increase in calcium coverage of the fiber compared to the control group and a twofold increase in interfacial stiffness. No significant increase in interfacial strength was determined, most likely due to the weakness of the CaP matrix, which was partially visible as residues on the monofilaments in the postfracture imaging. This study shows the potential of surfaces functionalized with aspartic acid as a simple alternative to complex polypeptide based functional groups for the adsorption of divalent ions such as calcium on poly-lactic acid in bone regenerating applications.

Aim: The main purpose of this work was to develop new protocols for high yield purification of secretory phospholipase A2 (PLA2) and to investigate its biophysical properties. Materials and methods: We have used a Pichia pastoris expression system for PLA2 expression and two-stage chromatography for its purification. The biophysical properties of PLA2 were investigated by circular dichroism. Results: A scalable method for high yield purification of recombinant Streptomyces violaceruber PLA2 was developed. The PLA2 from S. violaceruber was expressed in the methylotrophic yeast P. pastoris . Functional active phospholipase A2 with specific activity 73 U/mg was purified with a concentration of at least 3 mg/mL. The role of different divalent ions in PLA2 thermostability were evaluated. Ca 2+ and Ba 2+ ions significantly increased thermostability of the enzyme.

Introduction: Islet recovery from within alginate-based microcapsules is necessary for certain analytical assays like flow cytometry; however, this technology has not been widely characterized. In this study, we explore the ability of EDTA, EGTA, and sodium citrate to induce reverse alginate polymerization via chelation and assess the toxicity of each chelator on pancreatic islets., Methods: EDTA, EGTA, and sodium citrate were used to dissolve single-layered Ba 2+ alginate encapsulated islets and the rate of capsule breakdown calculated from analysis of imaging data. The effect of chelator exposure on islet viability and recovery was assessed using flow cytometry, while glucose-stimulated insulin release (GSIR) assay was used to measure effects on islet function., Results: EGTA demonstrated the most rapid microcapsule dissolving rate followed by EDTA and sodium citrate. Islet recovery was significantly better when encapsulated islets were treated with EDTA than EGTA and Na + citrate. A decrease in viability and increase in apoptotic cells were observed when encapsulated islets were treated with Na + citrate compared to islets treated with EDTA and EGTA. Islets treated with EDTA and EGTA demonstrated comparable stimulation index values to non-treated control. Conversely, islets treated with Na + citrate exhibited significantly decreased SI values compared to control. All chelator groups showed significantly lower insulin secretion than non-treated islets., Conclusion: Islet recovery from alginate microcapsule is possible using common chelators like Na + citrate, EDTA, and EGTA. Chelation of encapsulated islets using EDTA demonstrated the most efficient dissolving capabilities with the least toxicity toward islet recovery and health., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Despite decades of focused research, a detailed understanding of the fundamental physical processes that underpin biological systems (structures and processes) remains an open challenge. Within the present paper we report on biomimetic studies, which offer new insights into the process of cell division and the emergence of different cellular and multicellular structures. Experimental studies specifically investigated the impact of including different concentrations of charged bio-molecules (cytokinin and gibberellic acid) on the growth of BaCO 3 -SiO 2 based structures. Results highlighted the role of charge density on the emergence of long-range order, underpinned by a negentropic process. This included the growth of synthetic cell-like structures, with the intrinsic capacity to divide and change morphology at cellular and multicellular scales. Detailed study of dividing structures supports a hypothesis that cell division is dependent on the establishment of a charge-induced macroscopic quantum potential and cell-scale quantum coherence, which allows a description in terms of a macroscopic Schrödinger-like equation, based on a constant different from the Planck constant. Whilst the system does not reflect full correspondence with standard quantum mechanics, many of the phenomena that we typically associate with such a system are recovered. In addition to phenomena normally associated with the Schrödinger equation, we also unexpectedly report on the emergence of intrinsic spin as a macroscopic quantum phenomena, whose origins we account for within a four-dimensional fractal space-time and a macroscopic Pauli equation, which represents the non-relativistic limit of the Dirac equation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

DNA can form many structures beyond the canonical Watson-Crick double helix. It is now clear that noncanonical structures are present in genomic DNA and have biological functions. G-rich G-quadruplexes and C-rich i-motifs are the most well-characterized noncanonical DNA motifs that have been detected in vivo with either proscribed or postulated biological roles. Because of their independent sequence requirements, these structures have largely been considered distinct types of quadruplexes. Here, we describe the crystal structure of the DNA oligonucleotide, d(CCAGGCTGCAA), that self-associates to form a quadruplex structure containing two central antiparallel G-tetrads and six i-motif C-C+ base pairs. Solution studies suggest a robust structural motif capable of assembling as a tetramer of individual strands or as a dimer when composed of tandem repeats. This hybrid structure highlights the growing structural diversity of DNA and suggests that biological systems may harbor many functionally important non-duplex structures., (© The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Due to the high abundance of K + in environments and K + -induced high stability of G-quadruplex (G4), developing a selective G4-based fluorescent sensor for other metal ions with K + tolerance is a great challenge. Herein, we found that even in the presence of 15000-fold excess of K + , Ba 2+ exhibits a highly specific binding with a human telomeric G4 (htG4) in comparison with other G4-binding metal ions such as Pb 2+ and Sr 2+ . This specific binding event can be recognized by a natural fluorophore of hypericin with a lighting-up fluorescence response. Interestingly, inverting the polarity of the most 3' G in htG4 can sensitize the Ba 2+ response with the retaining Ba 2+ specificity and K + tolerance. This polarity inversion of htG4 causes a G4 conformation change in K + and the polarity-inverted htG4 tends to favorably dimerize in response to the Ba 2+ specific binding. To our knowledge, this is the first report that polarity inversion of G4 can be applied to construct a selective metal sensor with K + tolerance. Our findings will open a new way to conveniently regulate the G4 conformation and stability by polarity inversion towards developing high-performance sensors., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Thickened fluids are commonly used in the medical management of individuals who suffer swallowing difficulty (known as dysphagia). Previous studies have shown that the rheological properties of a liquid affect the flow behavior of the bolus in swallowing, such as pharyngeal transit time. While there is no doubt that shear rheology is a highly important factor for bolus flow, it is suspected that extensional properties of a liquid bolus also plays an important role in swallowing, due to elongation of the bolus as it flows through the oropharynx. Our aim in this work was to observe the effect of extensional viscosity on pharyngeal transit time and elongation of the bolus during swallowing. Eight samples of thickened liquid barium that were shear-controlled, but varied in extensional viscosity and two samples that were extensional-controlled, but varied in shear viscosity were swallowed by eight healthy individuals. Data were collected under lateral view of videofluoroscopy swallow study (VFSS); measures of pharyngeal transit time and the ratio of the length to the width of the bolus on the frame of Upper Esophageal Sphincter (UES) opening were taken from the VFSS recordings. It was observed that the pharyngeal transit time generally increases when the fluids are thickened to higher IDDSI consistency. Additionally, higher extensional viscosity fluids reduced the elongation of the bolus during swallowing, thus potentially reducing the risk of post-swallow residue due to bolus breakage. This study confirmed the relevance of the extensional viscosity of the bolus in swallowing.

With the increasing awareness of environmental protection, the greening of flame retardants has become an inevitable choice for flame retardant technology. Bio-based materials have the advantages of wide source, recyclability and green environmental protection, and have received extensive attention. In this work, chitosan and phytic acid as intumescent flame retardant system and metal ion as a synergist were built on cotton fabrics to achieve efficient flame retardancy by facile dip-pad-dry process. Microscale combustion calorimetry results manifested that the heat release rate values of coated samples were lower than that of uncoated samples. The peak heat release rate and total heat release of uncoated samples were 333.1 W/g and 13.1 kJ/g, while these values of samples coated CH/PA/Ba/PA were 129.1 W/g and 5.4 kJ/g respectively and char residues also were increased sharply owing to the phosphate groups promote the formation of char layer covering the surface of the cotton fabrics, which can prevent heat transfer. Scanning electron microscopy confirmed that there were much more bubbles on the surface of fibers for the coated CH/PA/Ba/PA after horizontal flame tests. The results indicated that the synergy of the intumescent flame retardant system was achieved by the addition of metal ions which could accelerate the produce of a large number of nonflammable gases. Horizontal flame test and limit oxygen index (LOI) test showed that the burning rate and LOI values of samples coated CH/PA/Ba/PA, CH/PA /CH/PA, PA/Ba/PA/Ba were 1.5 mm/s and 22.0, 2.0 mm/s and 20.2 and 2.5 mm/s and 18.0 respectively, compared to 3.3 mm/s and 16.2 of uncoated samples. The samples with intumescent flame retardant system and metal ions (CH/PA/Ba/PA) had best flame retardant performance. Moreover its weight gain (5.2%) was less than that (10.7%) of the sample only with intumescent flame retardant system (CH/PA /CH/PA). The less weight gain had less effect on the softness of cotton fabrics. As a result, the coating is expected to be applied in practice., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Produced water generated during unconventional oil and gas extractions contains a complex milieu of natural and anthropogenic potentially toxic chemical constituents including arsenic (As), chromium (Cr), and cadmium (Cd), naturally occurring radioactive materials (NORMs) including U and Ra, and a myriad of organic compounds. The human-ecological health risks and challenges associated with the disposal of produced water may be alleviated by understanding geochemical controls on processes responsible for the solubilization of potentially hazardous natural shale constituents to produced water. Here, we investigated, through a series of batch treatments, the leaching behavior of As, Se, Cu, Fe, Ba, Cr, Cd, and radioactive nuclides U, Ra from shale to produced water. Specifically, the effect of four major controls on element mobility was studied: (1) solution pH, (2) ionic strength of the solution, (3) oxic-anoxic conditions, and (4) an additive used in fracking fluid. The mobilization of metals and metalloids from shale was greatest in treatments containing sodium persulfate, an oxidant and a commonly used additive in fracture fluid. In the high ionic strength treatments, dissolved Ba concentrations increased 5-fold compared to low ionic strength treatments. Overall, anoxic conditions superimposed with low pH resulted in the largest increase of dissolved metals and radionuclides such as Ra. Overall, our results suggest that (1) limiting pore water acidification by injection of alkaline fluid in carbonate-low shale and (2) minimizing strong oxidizing conditions in shale formations may result in cost-effective in situ retention of produced water contaminants.

Gunshot residue, or GSR, can be a valuable tool in forensic science, but its importance depends greatly on how it is utilized during an investigation and applied in criminal courts. This comprehensive review defines what constitutes GSR resulting from a discharged firearm. Sampling methods and analytical testing instrumentation will be discussed along with data interpretation and limitations of analysis.

The development of optical thermometers operating within the first biological window (650-1000 nm) has drawn great interest lately in the biological and medical fields. Here a new type of luminescent thermometer relying on the intensity ratio between G 4 1-F 4 3 (652 nm) and F 2,3 3-H 6 3(691 nm) transitions in Tm 3+ /Yb 3+ :BaMoO 4 phosphor is reported under 980 nm excitation. The thermometry is found to be independent on the excitation power, benefiting the reduction of the measurement error. Moreover, it exhibits extremely high absolute sensitivity ranging from 210.5×10 -4 to 1034.5×10 -4   K -1 in 298-498 K. The maximal relative sensitivity and temperature resolutions (1.36%  K -1 and 0.37 K, respectively) are also among the highest values of those previous thermometric materials. This Letter provides guidance in selecting the suitable emission bands to construct the ratiometric luminescent thermometers with high performance.

A new set of differently hydrated barium and strontium squarates, namely poly[[triaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)barium] monohydrate], {[Ba(C 4 O 4 )(H 2 O) 3 ]·H 2 O} n (1), poly[[diaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)strontium] monohydrate], {[Sr(C 4 O 4 )(H 2 O) 2 ]·H 2 O} n (2), and poly[[triaqua(μ-1,2-dioxocyclobut-3-ene-1,2-diolato)barium/strontium(0.85/0.15)] monohydrate], {[Ba 0.85 Sr 0.15 (C 4 O 4 )(H 2 O) 3 ]·H 2 O} n (3), is reported. The study of their crystal structures indicates that all the complexes crystallize in the triclinic space group P-1. Complexes 1 and 3 have a rare combination of squarate units coordinated through monodentate O atoms to two different metal atoms and through two bidentate O atoms to three different metal atoms. Furthermore, they have three coordinated water molecules to give a coordination number of nine. The squarate ligands in complex 2 exhibit two different coordination modes: (i) monodentate O atoms coordinated to four different Sr atoms and (ii) two monodentate O atoms coordinated to two different metal atoms with the other two O atoms bidentate to four different Sr atoms. All the compounds decompose to give the respective carbonates when heated to 800 °C, as evidenced by thermogravimetry/differential thermal analysis (TG-DTA), which are clusters of nanoparticles. Complexes 1 and 3 show additional endothermic peaks at 811 and 820 °C, respectively, indicating the phase transition of BaCO 3 from an orthorhombic (α-Pmcn) to a trigonal phase (β-R3m). All three complexes have significant DNA-binding constants, ranging from 2.45 × 10 4 to 9.41 × 10 4  M -1 against EB-CT (ethidium bromide-calf thymus) DNA and protein binding constants ranging from 1.1 × 10 5 to 8.6 × 10 5 with bovine serum albumin. The in vitro cytotoxicity of the complexes is indicated by the IC 50 values, which range from 128.8 to 261.3 µg ml -1 . Complex 3 shows better BSA binding, antioxidant activity against the DPPH radical and cytotoxicity than complexes 1 and 2.

First principles calculations based on Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) method have been carried out to study the structural, electronic and optical properties of AeBi 2 O 6 (Ae = Sr and Ba) compounds. Optimal crystal structure is found out by optimizing lattice constants and internal parameters of constituent atoms using the Generalized Gradient Approximation as proposed by Wu-Cohen (GGA-WC). While the electronic, dielectric and optical properties of considered materials are investigated using original Becke-Johnson (BJ) potential as it reproduces very reasonable indirect band gaps as compared with experimental ones with value of 1.769 eV and 1.822 eV for SrBi 2 O 6 and BaBi 2 O 6 , respectively. The interactions between O-2p and Bi-5s-5p, which are responsible of photocatalytic activity of studied compounds, are demonstrated. Finally, the Debye quasi-harmonic model is used to calculate the thermodynamic properties including bulk modulus, heat capacities, thermal expansion, Debye temperature and entropy of AeBi 2 O 6 compounds. All of them are investigated for wide range of temperature up to 1200 K and of pressure up to 45 GPa., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Although the relationship between the incorporation of an element into otoliths and the concentration of the element in water has been extensively investigated in many fish species, the interactive effects of multiple elements in water on the otolith incorporation of an element are not adequately explored or well understood. In this study, 16 treatments in triplicate using strontium (Sr; 1, 2, 3 and 4 times the ambient baseline, 6.5 mg l-1) and barium (Ba; 1, 2, 4 and 6 times the ambient baseline, 40 μg l-1) as categorical variables in an orthogonal design were established to evaluate the relative or interactive effects of water elements on otolith elemental incorporation in juvenile flounder Paralichthys olivaceus (from 15 to 116 days post hatching). The results revealed that otolith incorporation (Me:CaOtolith) of Sr and Ba were positively dependent on the concentrations of the elements in water (Me:CaWater). Overall, Sr was incorporated into otoliths more efficiently than was Ba, and the partition efficiency (DMe) of both elements decreased with increasing water elemental concentrations. Increasing Sr concentrations in water appeared to negatively affect the uptake of Ba into otoliths rather than facilitate it, as previously reported in fish reared in freshwater and brackish water, or showed no effect on fish in seawater. Conversely, the Ba concentration in water did not influence the otolith uptake of Sr, which agrees with the findings for other fish species. When applying otolith microchemistry to fish ecology studies, it is essential to cautiously address the interactive effects of multiple elements in the environment on otolith elemental incorporation., Competing Interests: The authors have declared that no competing interests exist.

In the Ba 9 Lu 2 Si 6 O 24 (BLS) host, Ce 3+ shows cyan emissions peaking at 490 nm under 400 nm excitations. BLS:Tb 3+ only can be effectively excited by 254 nm light and gives rise to green emissions at 553 nm. However, both the cyan and green emissions can be obtained in BLS:Ce 3+ ,Tb 3+ under 400 nm excitations due to effective energy transfers from Ce 3+ to Tb 3+ . BLS:Mn 2+ shows red emissions peaking at 610 nm under 414 nm excitations. By co-doping Ce 3+ , Tb 3+ and Mn 2+ , tunable full-color emissions were obtained. The BLS:0.3Ce 3+ ,0.6Tb 3+ ,0.15Mn 2+ single phosphor exhibits a white light with a high color rendering index of 85 and a correlated color temperature of 5480 K under 400 nm excitation., (© 2019 John Wiley & Sons, Ltd.)

The formation and equilibria of Sr 2+ , Mg 2+ , Ca 2+ , Ba 2+ , and Y 3+ (M) complexes with a mixed-chelator comprising two biodegradable chelators (GLDA, L G , 2-[bis(carboxymethyl)amino] pentanedioic acid; HIDS, L H , 2-(1,2-dicarboxyethylamino)-3-hydroxy-butanedioic acid) in an aqueous matrix was evaluated. The potentiometric measurement results (ionic strength, 0.10 M; temperature, 25 ± 0.1 °C) confirmed the formation of 1:1:1 (M:L G :L H ) complexes and the experimental data sets were further used to derive the equilibrium constants for the ternary complexes. The [MHL G L H ] 5- complex was the dominant ternary complex with Sr 2+ , Mg 2+ , Ca 2+ , and Ba 2+ , while Y 3+ formed [M(OH) 2 L G L H ] 7- as the principal ternary species. The trend in the overall formation constants of the ML mix (L mix , L G :L H  = 1:1) complexes was in the order: Y 3+  > Ca 2+  > Mg 2+  > Sr 2+  > Ba 2+ . The ternary complexation trend was interpreted using the corresponding atomic radii and solution-phase electronegativities of the elements. The modes of interaction between the chelators and cations in the ML mix systems were subsequently deduced, and evaluated by using Gaussian 16W program. The relative stabilities of the ternary complexes (ΔlogK) were interpreted by comparison with the stabilities of the corresponding binaries, with negative ΔlogK values observed for all the ML mix complexes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

CaO-P 2 O 5 -SiO 2 -BaO-Fe 2 O 3 magnetic bioactive glasses were prepared via an optimized sol-gel method. This study is focused on investigating effects of magnetic content addition on the bioactive glass properties. To this aim, we evaluate the physical, rheological, and biocompatibility properties of synthesized magnetic bioactive glass. The morphology and composition of these glasses were studied using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The particle size was also determined using Laser Particle Size Analyzer (LPSA). The thermal measurements were carried out using Differential Thermal Analysis (DTA). For assessing the in-vitro bioactive character of synthesized glasses, the ability for apatite formation on their surface upon immersion in simulated body fluid (SBF) was checked using SEM, EDX and pH measurements. Furthermore, the Ca, Si, Ba and Fe ions in SBF were monitored using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The results showed that the addition of Ba and Fe in the glass composition affect formation of apatite layer onto the glass surfaces. Morphologies of the apatite layers were also different in which the bioactivity decreased with increasing Fe concentration, but the increase of Ba concentration led to an increase in bioactivity. However all of the synthesized glasses are still highly bioactive. Finally, this research demonstrates that the synthesized magnetic bioactive glasses are nontoxic and biocompatible and they can be used as thermoseeds for cancer hyperthermia studies., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: Immersion tests in purified water were conducted to evaluate the leaching behaviors of filler elements contained in computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin., Methods: Four commercial CAD/CAM resin composite blanks were tested: Shofu block HC 2 layer, Cerasmart, Katana Avencia block, and KZR-CAD HR Block 2. The specimens in the size of 10.0×12.0×2.0mm were immersed in a 50-mL conical tube containing 40mL of purified water, and then placed in a constant-temperature oven set at a temperature of 37, 60, 70, or 80°C and stored statically for 30 days. After storage, the concentrations of leached elements in the immersion solution were measured with an inductively coupled plasma atomic emission spectrometer. To characterize the surface of the specimen after the immersion test, secondary electron images were obtained., Results: The immersion test resulted in the leaching of Si, the main component, from all materials tested. Some materials were found to have leached high amount of Ba or Sr in addition to Si, and remarkable surface degradation was observed. The amount of leached elements increased with increased immersion temperatures., Conclusions: Filler elements in CAD/CAM composite resins used in this study leached into purified water. The leached elements and its quantities greatly differed among materials and depend on the types of the oxides composing the filler. The amounts of leached elements varied in a temperature-dependent manner., (Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.)