Bimetallic TiO2 Nanoparticles for Lignin-Based Model Compounds Valorization by Integrating an Optocatalytic Flow-Microreactor

The challenge of improving the activity of TiO₂ by modifying it with metals and using it for targeted applications in microreactor environments is an active area of research. Recently, microreactors have emerged as successful candidates for many photocatalytic reactions, especially for the selective oxidation process. The current work introduces ultrasound-assisted catalyst deposition on the inner walls of a perfluoro-alkoxy alkane (PFA) microtube under mild conditions. We report Cu-Au/TiO₂ and Fe-Au/TiO₂ nanoparticles synthesized using the sol–gel method. The obtained photocatalysts were thoroughly characterized by UV–Vis diffuse-reflectance spectroscopy (DRS), high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and N₂ physisorption. The photocatalytic activity under UV (375 nm) and visible light (515 nm) was estimated by the oxidation of lignin-based model aromatic alcohols in batch and fluoropolymer-based flow systems. The bimetallic catalyst exhibited improved photocatalytic selective oxidation. Herein, four aromatic alcohols were individually investigated and compared. In our experiments, the alcohols containing hydroxy and methoxy groups (coniferyl and vanillin alcohol) showed high conversion (93% and 52%, respectively) with 8% and 17% selectivity towards their respective aldehydes, with the formation of other side products. The results offer an insight into ligand-to-metal charge transfer (LMCT) complex formation, which was found to be the main reason for the activity of synthesized catalysts under visible light.     

Development of Novel Pyridine-Thiazole Hybrid Molecules as Potential Anticancer Agents

Novel pyridine-thiazole hybrid molecules were synthesized and subjected to physico-chemical characterization and screening of their cytotoxic action towards a panel of cell lines derived from different types of tumors (carcinomas of colon, breast, and lung, glioblastoma and leukemia), and normal human keratinocytes, for comparison. High antiproliferative activity of the 3-(2-fluorophenyl)-1-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-propenone 3 and 4-(2-{1-(2-fluorophenyl)-3-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-3-oxopropylsulfanyl}-acetylamino)-benzoic acid ethyl ester 4 was revealed. The IC₅₀ of the compound 3 in HL-60 cells of the acute human promyelocytic leukemia was 0.57 µM, while in the pseudo-normal human cell lines, the IC₅₀ of this compound was >50 µM, which suggests that the compounds 3 and 4 might be perspective anticancer agents. The detected selectivity of the derivatives 3 and 4 for cancer cell lines inspired us to study the mechanisms of their cytotoxic action. It was shown that preincubation of tumor cells with Fluzaparib (inhibitor of PARP1) reduced the cytotoxic activity of the derivatives 3 and 4 by more than twice. The ability of these compounds to affect DNA nativity and cause changes in nucleus morphology allows for the suggestion that the mechanism of action of the novel pyridine-thiazole derivatives might be related to inducing the genetic instability in tumor cells.     

Magneto‐sensitive Elastomers in a Homogeneous Magnetic Field: A Regular Rectangular Lattice Model

A theory of mechanical behaviour of the magneto‐sensitive elastomers is developed in the framework of a linear elasticity approach. Using a regular rectangular lattice model, different spatial distributions of magnetic particles within a polymer matrix are considered: isotropic, chain‐like and plane‐like. It is shown that interaction between the magnetic particles results in the contraction of an elastomer along the homogeneous magnetic field. With increasing magnetic field the shear modulus, G, for the shear deformation perpendicular to the magnetic field increases for all spatial distributions of magnetic particles. At the same time, with increasing magnetic field the Young's modulus, E, for tensile deformation along the magnetic field decreases for both chain‐like and isotropic distributions of magnetic particles and increases for the plane‐like distribution of magnetic particles.

     

Optimal cell approach to osmotic properties of finite stiff-chain polyelectrolytes

We propose a self-consistent geometry optimized cell model approach to study osmotic properties of stiff-chain polyelectrolyte solutions. In contrast with the usual monotonic Poisson-Boltzmann prediction, the cell model predicts the correct nonmonotonic dependence of the osmotic coefficient on concentration. A lower degree of polymerization is found to reduce significantly the counterion condensation in a typical dilute strong polyelectrolyte. The results agree quantitatively with simulations of a corresponding many-body bulk system up to a dense semidilute regime.     

Ultrametricity and metric betweenness in tangent spaces to metric spaces

The paper deals with pretangent spaces to general metric spaces. An ultrametricity criterion for pretangent spaces is found and it is closely related to the metric betweenness in the pretangent spaces.     

Computational study of cold ions trapped in a double-well potential

We report a rigorous computational treatment of quantum dynamics of cold ions in a double-well trap using the time-dependent Schrödinger equation. Our method employs a numerically accurate approach that avoids approximations, such as assumption of weak coupling between the wells; normal mode nature of vibrations; or harmonic approximation for energy spectrum of the double-well system. Our goal is to reproduce, from first principles, the process of energy swaps between the wells observed in the experiments at NIST [Nature 471, 196 (2011)] and Innsbruck [Nature 471, 200 (2011)]. The model parameters and the initial conditions are carefully chosen to mimic experimental conditions. We obtain accurate energies and wave functions of the system numerically, and study the evolution of motional wave packets to provide new insight. This model reproduces experimental results obtained by NIST and Innsbruck in detail. We explain the energy transfer in terms of wave packet dynamics in the asymmetric potential energy well. We also show that, for a localised initial wave packet, this phenomenon can be interpreted using the terms of classical dynamics, such as trajectory of motion governed by the well-known simple principle: the angle of reflection equals the angle of incidence.     

Enhanced electrochemical performance of LiNi0.83Co0.12Mn0.05O2 cathodes with a fast-ion conductor Li0.33La0.56TiO3 coating layer

Journal of Solid State Electrochemistry - Ni-rich layered cathode materials LiNixCoyMn(1-x–y)O2 (x ≥ 0.8) suffer from capacity decay due to structural deterioration during...     

Combinatorial Screening of Water/Proton Permeation of Self-Assembled Pillar[5]arene Artificial Water Channel Libraries

Artificial water channels (AWCs) that selectively transport water and reject ions through bilayer membranes have potential to act as synthetic Aquaporins (AQPs). AWCs can have a similar osmotic permeability, better stability, with simpler manufacture on a larger-scale and have higher functional density and surface permeability when inserted into the membrane. Here, we report the screening of combinatorial libraries of symmetrical and unsymmetrical rim-functionalized PAs A – D that are able to transport ca. 10⁷–10⁸ water molecules/s/channel, which is within 1 order of magnitude of AQPs’ and show total ion and proton rejection. Among the four channels, C and D are 3–4 times more water permeable than A and B when inserted in bilayer membranes. The binary combinations of A – D with different molar ratios could be expressed as an independent (linear ABA ), a recessive (inhibition AB , AC , DB , ACA ), or a dominant (amplification, DBD ) behavior of the water net permeation events.