BINA

The study of subtle effects on transport in semiconductors requires high-quality epitaxial structures with low defect density. Using hybrid molecular beam epitaxy (MBE), SrTiO films with low-temperature mobility exceeding 42,000 cmVs at low carrier density of 3 x 10 cm were achieved. A sudden and sharp decrease in residual resistivity accompanied by an enhancement in the superconducting transition temperature were observed across the second Lifshitz transition (LT) where the third band becomes occupied, revealing dominant intra-band scattering. These films further revealed an anomalous behavior in the Hall carrier density as a consequence of the antiferrodistortive (AFD) transition and the temperature-dependence of the Hall scattering factor. Using hybrid MBE growth, phenomenological modeling, temperature-dependent transport measurements, and scanning superconducting quantum interference device imaging, we provide critical insights into the important role of inter- vs intra-band scattering and of AFD domain walls on normal-state and superconducting properties of SrTiO.

Metal–support interactions have been widely utilized for optimizing the catalytic reactivity of oxide-supported Au nanoparticles. Optimized reactivity was mainly detected with small (1–5 nm) oxide-supported Au nanoparticles and correlated to highly reactive sites at the oxide–metal interface. However, catalytically active sites are not necessarily restricted to the interface but reside as well on the Au surface. Uncovering the interconnection between reactive sites located at the interface and those situated at the metal surface is of crucial importance for understanding the reaction mechanism on Au nanoparticles. Herein, high-spatial-resolution IR nanospectroscopy measurements were conducted to map the localized reactivity in hydrogenation reactions on oxide-supported Au particles while using nitro-functionalized ligands as probes molecules. Comparative analysis of the reactivity pattern on single particles supported …

Metal–support interactions have been widely utilized for optimizing the catalytic reactivity of oxide-supported Au nanoparticles. Optimized reactivity was mainly detected with small (1–5 nm) oxide-supported Au nanoparticles and correlated to highly reactive sites at the oxide–metal interface. However, catalytically active sites are not necessarily restricted to the interface but reside as well on the Au surface. Uncovering the interconnection between reactive sites located at the interface and those situated at the metal surface is of crucial importance for understanding the reaction mechanism on Au nanoparticles. Herein, high-spatial-resolution IR nanospectroscopy measurements were conducted to map the localized reactivity in hydrogenation reactions on oxide-supported Au particles while using nitro-functionalized ligands as probes molecules. Comparative analysis of the reactivity pattern on single particles supported …

We examine the radiation emitted by high-energy positrons channeled into silicon crystal samples. The positrons are modeled as semiclassical vector currents coupled to an Unruh-DeWitt detector to incorporate any local change in the energy of the positron. In the subsequent accelerated QED analysis, we discover a Larmor formula and power spectrum that are both thermalized by the acceleration. Thus, these systems explicitly exhibit thermalization of the detector energy gap at the celebrated Fulling-Davies-Unruh (FDU) temperature. Our derived power spectrum, with a nonzero energy gap, is then shown to have an excellent statistical agreement with high-energy channeling experiments and also provides a method to directly measure the FDU temperature. We also investigate the Rindler horizon dynamics and confirm that the Bekenstein-Hawking area-entropy law is satisfied in these experiments. As such, we …

Nanoparticles (NPs) based drugs for topical administration are gaining interest in the biomedical world. However, a study tool of their penetration depth to the different tissue layers without additional markers or contrast agents is required in order to relieve safety concerns. While common diagnostic tools, e.g. X-ray, computed tomography or magnetic resonance imaging, can provide in vivo detection of the metallic NPs, their resolution cannot determine the exact penetration depth to the thin skin layers. In this work, we propose the noninvasive nanophotonics iterative multi-plane optical property extraction (IMOPE) technique for the novel iron-based NPs detection in leishmaniasis lesions. The optical properties of the different tissue layers: epidermis, dermis, subcutaneous fat and muscle, were examined before and after topical drug administration. The potential topical drug was detected in the epidermis (∼13µm) and …

Imaging turbid media is range limited. In contrast, sensing the medium’s optical properties is possible in larger depths using the iterative multi-plane optical properties extraction technique. It analyzes the reconstructed reemitted light phase image. The root mean square of the phase image yields two graphs with opposite behaviors that intersect at µ’s,cp. These graphs enable the extraction of a certain range of the reduced scattering coefficient, µ’s. Here, we aim to extend the range of µ’s detection by optical magnification. We use a modified diffusion theory and show how µ’s,cp shifts with the varying magnification. The theoretical results were tested experimentally, showing that the technique can be adapted to different ranges of µ’s by changing the magnification.

Lithium-sulfur (Li-S) batteries promise high energy density for next-generation energy storage systems, yet many challenges remain. Li-S batteries follow a conversion chemistry, which radically differs from intercalation-based lithium-ion batteries. Recently, it has become clear that the chemistry of electrolyte solutions and their ability to stabilize polysulfide Li2Sx species formed by sulfur reduction have a critical effect on energy density and cycling performance. This review evaluates the key role of solution properties and polysulfide solvation. Factors that determine the solvation are discussed, including the solvent, salt, concentration, and interaction with Li-polysulfide species. Three fundamental types of electrolyte solution—moderately (conventional), sparingly, and highly solvating—are presented along with a multi-dimensional analysis of solution chemistry, polysulfide solubility, sulfur reaction pathway, Li2S …

Calcium-based battery systems are promising postlithium candidates; however, only a few amenable calcium materials were reported in nonaqueous electrolytes. Here, reversible storage of Ca2+ ions in aqueous and nonaqueous electrolyte solutions is shown for crystalline 3,4,9,10-perylene tetracarboxylic dianhydride. The carbonyl functional groups and the π-electrons constitute redox centers, which can reversibly interact with divalent ions. This phenomenon was clearly uncovered by combined electrochemistry, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, and ex situ X-ray diffraction analyses. Very promising calcium storage performances are shown with a highly reversible capacity around ∼158 mAh g–1 at a rate of 10 mA g–1 with an average voltage of ∼2.3 V band sufficient capacity retention in saturated Ca …

Three different Terahertz quantum-cascade-laser designs supporting clean n-level systems were analyzed using nonequilibrium Green’s functions. In clean n-level systems, most of the electrons occupy the active laser levels, with thermally activated leakage channels being suppressed almost entirely up to room temperature. Simulations of the three designs, namely a resonant phonon design, a two-well design, and a split-well direct-phonon design were investigated. The results from the simulations indicated that the two-well design would perform best overall, in terms of variations in current density, interface roughness, and ionized impurity scattering. We conclude that future research aiming to improve the temperature performance of such laser designs should be based on a two-well design.

Understanding the charge transport properties of proteins at the molecular scale is crucial for the development of novel bioelectronic devices. In this contribution, we report on the preparation and electrical characterization of thin films of bacteriorhodopsin grafted on the surface of titanium nitride via aminophosphonate linkers. Thickness analysis using atomic force microscopy revealed a protein film thickness of 8.2±1.5 nm, indicating the formation of a protein bilayer. Electrical measurements were carried out in the dry state, in a vertical arrangement with a eutectic gallium-indium (EGaIn) or an evaporated Ti/Au top contact. DC current-voltage measurements yielded comparable effective tunneling decay constants for the EGaIn top contact and for the Ti/Au top contact. The results presented herein may establish a novel platform for studying charge transport via protein molecules in a solid-state …

We study the aberrations of four-wave mixing based time lenses resulting from the cross-phase modulations of the pump wave. These temporal aberrations have no spatial equivalent and are important when imaging weak signals with strong pump waves. We show that as the pump power increases, the cross-phase modulations of the pump are responsible for shifting, defocusing, and imposing temporal coma aberrations on the image. We present experimental results of these aberrations with high agreement to analytical and numerical calculations.

Ni-rich layered oxide LiNi1 – x – yCoxMnyO2 (1 – x – y > 0.5) materials are favorable cathode materials in advanced Li-ion batteries for electromobility applications because of their high initial discharge capacity. However, they suffer from poor cycling stability because of the formation of cracks in their particles during operation. Here, we present improved structural stability, electrochemical performance, and thermal durability of LiNi0.85Co0.1Mn0.05O2(NCM85). The Nb-doped cathode material, Li(Ni0.85Co0.1Mn0.05)0.997Nb0.003O2, has enhanced cycling stability at different temperatures, outstanding capacity retention, improved performance at high discharge rates, and a better thermal stability compared to the undoped cathode material. The high electrochemical performance of the doped material is directly related to the structural stability of the cathode particles. We further propose that Nb-doping in NCM85 …

Simple Summary Inflammatory Bowel Disease (IBD) is a complex and multifactorial systemic disease of the gastrointestinal tract, characterized by chronic inflammation, thus resulting in tissue damage and, occasionally, in cancer development. Although the precise origin is still elusive, it is widely considered a disease of modern society, caused by a complex interaction between environment, genetic, immune system, and gut microflora (microbiota). Potentially affected by all the above-mentioned variables, which interplay are highly heterogeneous, the disease appears to be patient-specific. The latter phenomenon, together with the uncertain origin, also contributes to the lack of optimal clinical treatment of these patients. Therefore, the development of appropriate models is crucial to push the research forward and to define new valuable therapeutic approaches. Although tissue biopsies and/or animal models represent the best models to study IBD onset, progression, and clinical interventions, they are both affected by limitations such as invasiveness, cost- and time-consuming, and ethical issues such as animal suffering. Here we propose a novel approach based on the cultivation of mouse tissues (colon) in an ex vivo microfluidic device (Gut-Ex-Vivo System, GEVS) to study IBD. We demonstrate that explanted mouse tissues cultivated in our GEVS can be appropriately stimulated to recapitulate the onset of the disease, in a time- and cost- effective manner. Abstract Inflammatory bowel disease (IBD) is a complex, chronic, and dysregulated inflammatory condition which etiology is still largely unknown. Its prognosis …

Personalized cancer treatment based on specific mutations offers targeted therapy and is preferred over “standard” chemotherapy. Proteinoid polymers produced by thermal step-growth polymerization of amino acids may form nanocapsules (NCs) that encapsulate drugs overcoming miscibility problems and allowing passive targeted delivery with reduced side effects. The arginine-glycine-glutamic acid (RGD) sequence is known for its preferential attraction to αvβ3 integrin, which is highly expressed on neovascular endothelial cells that support tumor growth. Here, tumor-targeted RGD-based proteinoid NCs entrapping a synergistic combination of Palbociclib (Pal) and Alpelisib (Alp) were synthesized by self-assembly to induce the reduction of tumor cell growth in different types of cancers. The diameters of the hollow and drug encapsulating poly (RGD) NCs were 34±5 and 22±3 nm, respectively; thereby, their drug targeted efficiency is due to both passive and active targeting. The encapsulation yield of Pal and Alp was 70 and 90%, respectively. In vitro experiments with A549, MCF7 and HCT116 human cancer cells demonstrate a synergistic effect of Pal and Alp, controlled release and dose dependence. Preliminary results in a 3D tumor spheroid model with cells derived from patient-derived xenografts of colon cancer illustrate disassembly of spheroids, indicating that the NCs have therapeutic potential. View Full-Text

Calcium-based battery systems are promising postlithium candidates; however, only a few amenable calcium materials were reported in nonaqueous electrolytes. Here, reversible storage of Ca2+ ions in aqueous and nonaqueous electrolyte solutions is shown for crystalline 3,4,9,10-perylene tetracarboxylic dianhydride. The carbonyl functional groups and the π-electrons constitute redox centers, which can reversibly interact with divalent ions. This phenomenon was clearly uncovered by combined electrochemistry, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, and ex situ X-ray diffraction analyses. Very promising calcium storage performances are shown with a highly reversible capacity around ∼158 mAh g–1 at a rate of 10 mA g–1 with an average voltage of ∼2.3 V band sufficient capacity retention in saturated Ca …

The ability to direct neurons into organized neural networks has great implications for regenerative medicine, tissue engineering, and bio-interfacing. Many studies have aimed at directing neurons using chemical and topographical cues. However, reports of organizational control on a micron-scale over large areas are scarce. Here, an effective method has been described for placing neurons in preset sites and guiding neuronal outgrowth with micron-scale resolution, using magnetic platforms embedded with micro-patterned, magnetic elements. It has been demonstrated that loading neurons with magnetic nanoparticles (MNPs) converts them into sensitive magnetic units that can be influenced by magnetic gradients. Following this approach, a unique magnetic platform has been fabricated on which PC12 cells, a common neuron-like model, were plated and loaded with superparamagnetic nanoparticles. Thin films of ferromagnetic (FM) multilayers with stable perpendicular magnetization were deposited to provide effective attraction forces toward the magnetic patterns. These MNP-loaded PC12 cells, plated and differentiated atop the magnetic platforms, were preferentially attached to the magnetic patterns, and the neurite outgrowth was well aligned with the pattern shape, forming oriented networks. Quantitative characterization methods of the magnetic properties, cellular MNP uptake, cell viability, and statistical analysis of the results are presented. This approach enables the control of neural network formation and improves neuron-to-electrode interface through the manipulation of magnetic forces, which can be an effective tool for in vitro …

Production of multilayered microstructures composed of conducting and insulating materials is of great interest as they can be utilized as microelectronic components. Current proposed fabrication methods of these microstructures include top-down and bottom-up methods, each having their own set of drawbacks. Laser-based methods were shown to pattern various materials with micron/sub-micron resolution; however, multilayered structures demonstrating conducting/insulating/conducting properties were not yet realized. Here, we demonstrate laser printing of multilayered microstructures consisting of conducting platinum and insulating silicon oxide layers by a combination of thermally driven reactions with microbubble-assisted printing. PtCl2 dissolved in N-methyl-2-pyrrolidone (NMP) was used as a precursor to form conducting Pt layers, while tetraethyl orthosilicate dissolved in NMP formed insulating silicon …

The present work considers the production of a cheap and effective sorbent based on natural clay from the Kyzylsok deposit (Almaty region) in order to purify wastewater from heavy metal ions (Cd 2+, Pb 2+). It was found that the starting material is applicable for the extraction of Cd 2+ ions (the degree of extraction is (97.00±1.99)%), while for the extraction of Pb 2+ ions the initial clay must be modified. The modification was carried out using polyvinylpyrrolidone (PVP). The degree of extraction of Pb 2+ ions with modified clay increased from (70.00±1.77)% to (98±1.13)% The influence of PVP concentration in the composite material (modified clay) on its sorption properties was studied: the optimal concentration of PVP was 0.1% solution. The desorption of metal ions was also investigated in the work, it does not exceed 2%. It was found that the sorption process is described by the monomolecular Langmuir isotherm …