Adsorptive Removal of Manganese Ions from Polluted Aqueous Media by Glauconite Clay-Functionalized Chitosan Nanocomposites

The presence of Mn(II) in water exceeding the permitted concentration limits declared by the World Health Organization (WHO) influences individuals, animals, and the ecosystem negatively. Therefore, there is a necessity for an efficient material to eliminate this potentially toxic element from wastewater. We herein focused on the adsorptive removal of Mn(II) ions from polluted aqueous media using natural Egyptian glauconite clay (G) and its nanocomposites with modified chitosan (CS). We applied modified chitosan with glutaraldehyde (GL), ethylenediaminetetraacetic acid (EDTA), sodium dodecyl sulfate (SDS), and cetyltrimethyl ammonium bromide (CTAB). The utilized nanocomposites were referred to as GL-CS/G, EDTA-GL-CS/G, SDS-CS/G, and CTAB-CS/G, respectively. The point of zero charge values of the materials were estimated. The adsorption properties of the G clay and its nanocomposites toward the removal of Mn(II) ions from polluted aqueous media as well as the adsorption mechanism were explored using a batch technique. The glauconite (G) and its nanocomposites: GL-CS/G, CTAB-CS/G, EDTA-GL-CS/G, and SDS-CS/G, exhibited maximum adsorption capacity values of 3.60, 24.0, 26.0, 27.0, and 27.9 mg g^?1, respectively. The adsorption results fitted well the Langmuir isotherm and pseudo-second-order kinetic models. The estimated thermodynamic parameters: ΔH° (from 1.03 to 5.55 kJ/mol) and ΔG° (from ? 14.5 to ? 18.8 kJ/mol), indicated that Mn(II) ion adsorption process was endothermic, spontaneous, and physisorption controlled. Furthermore, the obtained adsorption results are encouraging and revealing a great potentiality for using the modified adsorbents as accessible adsorbents for Mn(II) ion removal from polluted aqueous solutions, depending on their reusability, high stability, and good adsorption capacities.

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Identification of Novel Fragments Binding to the PDZ1-2 Domain of PSD-95

Inhibition of PSD-95 has emerged as a promising strategy for the treatment of ischemic stroke, as shown with peptide-based compounds that target the PDZ domains of PSD-95. In contrast, developing potent and drug-like small molecules against the PSD-95 PDZ domains has so far been unsuccessful. Here, we explore the druggability of the PSD-95 PDZ1-2 domain and use fragment screening to investigate if this protein is prone to binding small molecules. We screened 2500 fragments by fluorescence polarization (FP) and validated the hits by surface plasmon resonance (SPR), including an inhibition counter-test, and found four promising fragments. Three ligand efficient fragments were shown by ¹H,¹⁵N HSQC NMR to bind in the small hydrophobic P⁰ pockets of PDZ1-2, and one of them underwent structure-activity relationship (SAR) studies. Overall, we demonstrate that fragment screening can successfully be applied to PDZ1-2 of PSD-95 and disclose novel fragments that can serve as starting points for optimization towards small-molecule PDZ domain inhibitors.     

In Vivo Albumin-Binding of a C-Functionalized Cyclam Platform for 64Cu-PET/CT Imaging in Breast Cancer Model

An improved glucose-chelator-albumin bioconjugate (GluCAB) derivative, GluCAB-2^Mal, has been synthesized and studied for in vivo ⁶⁴Cu-PET/CT imaging in breast cancer mice models together with its first-generation analogue GluCAB-1^Mal. The radioligand works on the principle of tumor targeting through the enhanced permeability and retention (EPR) effect with a supportive role played by glucose metabolism. [⁶⁴Cu]Cu-GluCAB-2^Mal (99 % RCP) exhibited high serum stability with immediate binding to serum proteins. In vivo experiments for comparison between tumor targeting of [⁶⁴Cu]Cu-GluCAB-2^Mal and previous-generation [⁶⁴Cu]Cu-GluCAB-1^Mal encompassed microPET/CT imaging and biodistribution analysis in an allograft E0771 breast cancer mouse model. Tumor uptake of [⁶⁴Cu]Cu-GluCAB-2^Mal was clearly evident with twice as much accumulation as compared to its predecessor and a tumor/muscle ratio of up to 5 after 24 h. Further comparison indicated a decrease in liver accumulation for [⁶⁴Cu]Cu-Glu-CAB-2^Mal.     

Interfacial microstructure and mechanical properties of Ti3SiC2 ceramic and TC11 alloy joint diffusion bonded with a Cu interlayer

Reliable joints of Ti₃SiC₂ ceramic and TC11 alloy were diffusion bonded with a 50 μm thick Cu interlayer. The typical interfacial structure of the diffusion boned joint, which was dependent on the interdiffusion and chemical reactions between Al, Si and Ti atoms from the base materials and Cu interlayer, was TC11/α-Ti + β-Ti + Ti₂Cu + TiCu/Ti₅Si₄ + TiSiCu/Cu(s, s)/Ti₃SiC₂. The influence of bonding temperature and time on the interfacial structure and mechanical properties of Ti₃SiC₂/Cu/TC11 joint was analyzed. With the increase of bonding temperature and time, the joint shear strength was gradually increased due to enhanced atomic diffusion. However, the thickness of Ti₅Si₄ and TiSiCu layers with high microhardness increased for a long holding time, resulting in the reduction of bonding strength. The maximum shear strength of 251 ± 6 MPa was obtained for the joint diffusion bonded at 850 °C for 60 min, and fracture primarily occurred at the diffusion layer adjacent to the Ti₃SiC₂ substrate. This work provided an economical and convenient solution for broadening the engineering application of Ti₃SiC₂ ceramic.     

Fabrication of different conductive matrix supported binary metal oxides for supercapacitors applications

Here, we have fabricated the spinel binary-metal oxide (FeCo₂O₄) via a solvent-free and cost-effective approach. The nanocomposites of the as-fabricated binary-metal spinel oxide have been prepared with three different conductive-matrices, namely r-GO, CNTs, and PANI, via ultra-sonication approach. The spinel phase and surface functionalities of the fabricated FeCo₂O₄ sample have been confirmed via XRD and FT-IR analyses, respectively. The morphological-structure and elemental composition of the fabricated samples have been probed via FESEM and EDX results. The role of added conductive-matrices in the improvement of the electrical conductivities of the fabricated nanocomposites has been investigated via I–V experiments. The electrochemical experiments, conducted in half-cell configuration, showed that FeCo₂O₄/PANI nanocomposite exhibited the highest specific capacitance (658.9 Fg^-1) than that of the remaining two nanocomposites. Furthermore, FeCo₂O₄/PANI nanocomposite exhibited excellent cyclic stability as it lost just 8.3% of its initial specific capacitance even after 3000 cyclic tests. The superior capacitive-activity of the FeCo₂O₄/PANI nanocomposite is accredited to its high conductivity, large surface area, and synergy effects between the pseudocapacitance derived from the PANI and FeCo₂O₄ nanostructure. The electrochemical and electrical measurements suggested that FeCo₂O₄/PANI nanostructure is an emerging contender for energy storage applications.     

A novel ceramic matrix composite based on YNbO4–TiO2 for microwave applications

This work presents the dielectric properties of YNbO₄ (YNO)–TiO₂ composites in the microwave range. X-ray diffraction analysis demonstrates that the addition of TiO₂ to YNO results in the formation of a Y(Nb_0.5Ti_0.5)₂O₆ phase. In the microwave range, the values of permittivity and dielectric loss did not present major changes with the increment of TiO₂. Moreover, the addition of TiO₂ results in an improvement in the thermal stability of YNO, with YNO63 demonstrating a resonant frequency of ?8.96 ppm.°C^?1. We utilised numerical simulations to evaluate the behaviour of these materials as dielectric resonator antennae and it is found that they exhibit a reflection coefficient below ?10 dB at the resonant frequency, with a realised gain of 4.94 – 5.76 dBi, a bandwidth of 665–1050 MHz and a radiation efficiency above 84%. Our results indicate that YNO–TiO₂ composites are interesting candidates for microwave operating devices.     

Microstructure induced ultra-high energy storage density coupled with rapid discharge properties in lead-free Ba0.9Ca0.1Ti0.9Zr0.1O3–SrNb2O6 ceramics

Novel lead-free (1-x)Ba_0·9Ca_0·1Ti_0·9Zr_0·1O₃-xSrNb₂O₆ ceramics were synthesized via a two-step high energy ball milling process. The evolution of microstructural properties, phase transformation, and energy storage characteristics was comprehensively investigated to assess the applicability of material in multi-layered ceramic capacitors. The substitution of SrNb₂O₆ (SNO) in Ba_0·9Ca_0·1Ti_0·9Zr_0·1O₃ (BTCZ) has resulted in substantial improvement in materials density along with a small increase in the grain size of the synthesized ceramic. A thorough microstructural investigation indicates an excellent dispersibility and compatibility between BTCZ and SNO phases. With an increase in SNO substitution, a transition from typical ferroelectric to relaxor ferroelectric has been observed, which has led to a significantly slimmer ferroelectric loop along with frequency dispersive dielectric properties. The optimized composition (i.e., x = 0.10) exhibits an ultra-high recoverable energy density of 2.68 J/cm³ along with a moderately high energy efficiency of 83.4%. Further, SNO substituted samples have also shown an enhancement in breakdown strength. The improvement in energy storage performance and breakdown strength of SNO substituted BTCZ composites are mainly attributed to relatively homogeneous grain morphology, optimum grain size, microstructural density, and improved grain boundary interface.     

Structure-conductivity relationship of PrBaMnMoO6-δ through in-situ measurements: A neutron diffraction study

The structural and electrochemical properties of the double perovskite-type oxide, PrBaMnMoO_6-δ, was investigated using neutron diffraction with in-situ conductivity measurement under a dry Argon atmosphere from 25 °C to 700 °C. A Rietveld refinement of the neutron diffraction data confirmed monoclinic symmetry in the P2₁/n space group. Rietveld refinement also confirms the unit cell parameters of a = 5.6567 (1) Å, b = 5.6065 (2) Å, c = 7.9344 (1) Å and β = 84.43° with reliable atomic positions and refinement factors (R-factors). Neutron diffraction data refinement shows two minor phases (<5%), an orthorhombic AB₂O₅ type phase of PrMn₂O₅ in the Pbam (No. 32) space group with unit cell parameters, a = 7.9672 (1) Å, b = 8.9043 (2) Å and c = 5.8540 (1) Å and a scheelite phase of BaMoO₄ in the tetragonal I4₁/a (88) space group with the unit cell parameters, a = b = 5.9522 (1) Å, and c = 12.3211 (2) Å. Morphological images revealed a porous and intertwined microstructure. In-situ conductivity measurement shows that the total conductivity of this material was 130.84 Scm^?1 at 700 °C.