BINA

In this work, we elucidate the crucial role of borate anions ([B(OH)4]-) for the electrocatalytic urea oxidation reaction (UOR) using a nanoporous metallic nickel (NP-Ni) catalyst grown on Si substrates. The UOR activity of the NP-Ni catalyst has been studied at various boric acid (H3BO3) concentrations, demonstrating superior activity at a specific electrolytic composition of 0.5 M KOH, 0.33 M urea, and 50 mM of H3BO3. Based on a wide range of electrochemical techniques, such as, cyclic voltammetry (CV), linear sweep voltammetry (LSV), Pb-anodic deposition, and chronoamperometry (CA), we develop a potential mechanism for the [B(OH)4]--mediated UOR. The high double layer capacitance, surface density of Ni redox sites, and urea oxidation currents, clearly demonstrate the significant impact of [B(OH)4]- during electrolysis. Furthermore, we find that UOR catalyzed by the NP-Ni is controlled by diffusion both in presence and absence of [B(OH)4]-. Finally, a set of physical characterizations, including XPS, SEM, and TEM were performed to correlate the composition and structure of the NP-Ni to the [B(OH)4]--mediated increased UOR activity. The boosted UOR we obtain can open new avenues for treatment of wastewater and assist with environmental remediation.

Rechargeable Zn-air batteries with near-neutral electrolytes hold promise as cheap, safe and sustainable devices, but they suffer from slow charge kinetics and remain poorly studied. Here we reveal a charge storage mechanism of near-neutral Zn-air batteries that is mediated by H2O2 formation upon cell discharge and its oxidation upon charge. The manifestation of this mechanism strongly depends on the electrolyte composition and positive electrode material, being pronounced when ZnSO4 solutions and carbon nanotubes are employed. Oxidation of dissolved H2O2 is facile, enabling oxygen evolution reaction (OER) at low potentials (~1.5 V vs. Zn2+/Zn) which, in contrast to conventional four-electron OER, does not induce corrosion of carbon electrodes. Facilitation of the H2O2-mediated pathway might therefore be helpful for developing high-performance near-neutral Zn-air batteries.

We investigate a system of Brownian particles weakly bound by attractive parity-symmetric potentials that grow at large distances as , with . The probability density function at long times reaches the Boltzmann-Gibbs equilibrium state, with all moments finite. However, the system's relaxation is not exponential, as is usual for a confining system with a well-defined equilibrium, but instead follows a stretched exponential with exponent . This problem is studied from three perspectives. First, we propose a straightforward and general scaling rate-function solution for . This rate-function, which is an important tool from large deviation theory, also displays anomalous time scaling and a dynamical phase transition. Second, through the eigenfunctions of the Fokker-Planck operator, we obtain, using the WKB method, more complete solutions that reproduce the rate function approach. Finally, we show how the alternative path-integral formalism allows us to recover the same results, with the above rate-function being the solution of the classical Hamilton-Jacobi equation describing the most probable path. Properties such as parity, the role of initial conditions, and the dynamical phase transition are thoroughly studied in all three approaches.

The scattering-type Scanning Near-Field Optical Microscope (s-SNOM) is acknowledged as an excellent tool to investigate the optical properties of different materials and biological samples at the nanoscale. In this study we show that s-SNOM data are susceptible to being affected by specific artefacts related to the light diffraction phenomena and to stray contributions from shallow buried, contrast-active, structures. We focus on discussing the diffraction contributions from sample edges, next to those corresponding to one- or two-dimensional periodic structures, and undesired contributions from shallow buried periodic features. Each scenario was examined individually through both experimental methods and simulations. Our experimental findings reveal that such artefacts affect not only s-SNOM images demodulated at the direct-current (DC) component and the fundamental frequency, but also images demodulated at higher harmonic frequencies. We show that image artefacts caused by diffraction resemble the undesirable effects caused by illumination with a laser beam of unstable intensity, and that buried features can yield s-SNOM signals that cannot be distinguished from those originating from the sample surface, in absence of prior knowledge of the sample structure. Performed simulations confirm these experimental findings. This work enhances the understanding of s-SNOM data and paves the way for new data acquisition and postprocessing methods that can enable next-generation s-SNOM imaging and spectroscopy with significantly enhanced signal-to-noise ratio and resolution.

Semi Insulating GaAs alpha detectors with anode GaAs P+ contact layer were fabricated and characterized. The contact layer growth was carried out by Metal Organic Chemical Vapor Deposition (MOCVD) and the detector performances were compared to the performances of a front Schottky contact detector. The front side Schottky contact suffers from electron injection into the GaAs substrate. This injection is eliminated by using a P+ anode blocking layer with an ohmic contact, resulting in a reduction of leakage current at reverse bias values of up to 70 V. For example, at 30 V the leakage currents were 50 nA/cm2 and 150 nA/cm2 for the ohmic and the Schottky anode detectors, respectively. For both detectors, the charge collection efficiency was increased by a factor of ~2 after grinding the substrates from 650 μm to 310 μm thickness, with no leakage current degradation. In addition, rapid thermal process (RTP …

Researchers have been investigating the physical and morphological properties of biodegradable polymer and copolymer films, blending them with other chemicals to solve challenges in medical, industrial, and eco-environmental fields. The present study introduces a novel, straightforward method for preparing biodegradable hydrogels based on polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) for medical applications. The resulting PVA/PVP-based hydrogel uniquely combines the water absorbency, biocompatibility, and biodegradability of the polymer composite. For hygiene products and medical uses, such as wound healing, hydrogen peroxide (HP) was encapsulated in the PVA/PVP hydrogels for controlled release application. Incorporating PVP into PVA significantly enhances the hydrogel water absorbency and improves the mechanical properties. However, to mitigate the disadvantage of high water absorbency which could result in undesired early dissolution, efforts were made to increase the water resistance and the mechanical characteristics of these hydrogels using freeze–thaw (F/T) cycles and chemical crosslinking PVA chains with trisodium trimetaphosphate (STMP). The resulting hydrogels serve as environmentally friendly bio-based polymer blends, broadening their applications in medical and industrial products. The structural and morphological properties of the hydrogel were characterized using Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscope analysis (E-SEM), and water-swelling tests. The HP controlled release rate was evaluated through kinetic release experiments using …

Even in a simple stochastic process, the study of the full distribution of time integrated observables can be a difficult task. This is the case of a much-studied process such as the Ornstein-Uhlenbeck process where, recently, anomalous dynamical scaling of large deviations of time integrated functionals has been highlighted. Using the mapping of a continuous stochastic process to a continuous time random walk via the "excursions technique'', we introduce a comprehensive formalism that enables the calculation of the complete distribution of the time-integrated observable , where is a positive integer and is the random velocity of a particle following Ornstein-Uhlenbeck dynamics. We reveal an interesting connection between the anomalous rate function associated with the observable and the statistics of the area under the first-passage functional during an excursion. The rate function of the latter, analyzed here for the first time, exhibits anomalous scaling behavior and a dynamical phase transition, both of which are explored in detail. The case of the anomalous scaling of large deviations, originally associated to the presence of an instantonic solution in the weak noise regime of a path integral approach, is here produced by a so called "big jump effect'', in which the contribution to rare events is dominated by the largest excursion. Our approach, which is quite general for continuous stochastic processes, allows to associate a physical meaning to the anomalous scaling of large deviations, through the big jump principle.

A-to-I RNA editing is the most common non-transient epitranscriptome modification. It plays several roles in human physiology and has been linked to several disorders. Large-scale deep transcriptome sequencing has fostered the characterization of A-to-I editing at the single nucleotide level and the development of dedicated computational resources. REDIportal is a unique and specialized database collecting ∼16 million of putative A-to-I editing sites designed to face the current challenges of epitranscriptomics. Its running version has been enriched with sites from the TCGA project (using data from 31 studies). REDIportal provides an accurate, sustainable and accessible tool enriched with interconnections with widespread ELIXIR core resources such as Ensembl, RNAcentral, UniProt and PRIDE. Additionally, REDIportal now includes information regarding RNA editing in putative double-stranded RNAs …

We use an array of nine elliptical Planar Hall Effect (PHE) sensors and machine learning algorithms to map the magnetic signal generated by a magnetic source. Based on the obtained mapping, the location and nature of the magnetic source can be determined. The sensors are positioned at the vertices of a symmetrical and evenly spaced 3 × 3 grid. The main electronic card orchestrates their measurement by supplying the required driving current and amplifying and sampling their output in a synchronized manner. A two-dimensional interpolation of the data collected from the nine sensors fails to yield a satisfactory mapping. To address this, we employed the Levenberg–Marquardt Algorithm (LMA) as a deterministic optimization method to estimate the magnetic source’s position and parameters, as well as machine earning (ML) algorithms, which consist of a Fully Connected Neural Network (FCNN). While LMA provided reasonable results, its reliance on a sparse sensor network and initial guesses for variables limited its accuracy. We show that the mapping is significantly improved if the data are processed with an FCNN that undergoes training and testing. Using simulations, we demonstrate that achieving similar improvement without ML would require increasing the number of sensors to more than 50.

Amidst the pervasive threat of bacterial afflictions, the imperative for advanced antibiofilm surfaces with robust antimicrobial efficacy looms large. This study unveils a sophisticated ultrasonic synthesis method for cellulose nanocrystals (CNCs, 10–20 nm in diameter and 300–900 nm in length) and their subsequent application as coatings on flexible substrates, namely cotton (CC-1) and membrane (CM-1). The cellulose nanocrystals showed excellent water repellency with a water contact angle as high as 148° on the membrane. Noteworthy attributes of CNC-coated substrates include augmented reactive oxygen species (ROS) generation, heightened surface hydrophobicity, and comprehensive suppression of both drug-sensitive (MDR E. coli and MRSA) and susceptible (E. coli and S. aureus) planktonic and biofilm bacterial proliferation. In contrast, the uncoated substrates display 100% bacterial growth for the above bacteria. Empirical data corroborate the pronounced biofilm mass reduction capabilities of CNC-coated substrates across all tested bacterial strains. Elucidation of underlying mechanisms implicates ROS generation and electrostatic repulsion between CNCs and bacterial membranes in the disruption of mature biofilms. Hydroxyl radicals, superoxide, and hydrogen peroxide possess formidable reactivity, capable of disrupting essential biomolecules such as DNA, proteins, and lipids. The engineered CNC-coated substrates platform evinces considerable promise in the realm of infectious disease management, offering a cogent blueprint for the development of novel antimicrobial matrices adept at combating bacterial infections with …

X ray matter interactions are intrinsically weak, and the high energy and momentum of X rays pose significant challenges to applying strong light matter coupling techniques that are highly effective at longer wavelengths for controlling and manipulating radiation. Techniques such as enhanced coupling between light and electrons at a metal dielectric interface or within nanostructures, as well as the Purcell effect where spontaneous emission is amplified near a metallic surface are not applicable to X rays due to their fundamentally different energy and momentum scales. Here we present a novel approach for coupling X rays to surface plasmon polaritons by entangling X ray photons with SPPs in the ultraviolet range through X ray to UV spontaneous parametric down conversion in aluminum. The distinct characteristics of the SPPs are imprinted onto the angular and energy dependence of the detected X ray photons, as demonstrated in this work. Our results highlight the potential to control X rays using SPPs, unlocking exciting opportunities to enhance X ray matter interactions and explore plasmonic phenomena with atomic scale resolution a capability uniquely enabled by X rays.

Raman spectroscopy is an extremely powerful laser-based method for characterizing materials based on their unique inelastic scattering spectrum. Ultimately, the power of the technique is limited by the resolution of the spectrometer. Here we introduce a new method for achieving Super-Spectral-Resolution Raman Spectroscopy (SSR-RS), by angle-tuning a Fabry–Pérot (F-P) etalon filter that we incorporated in a micro-Raman setup. A monolithically coated F-P etalon structure, only 1.686 mm in thickness, was mounted onto an angle-tunable motorized stage, and Raman spectra were automatically acquired for many different angles of the etalon. Using a low-resolution grating of 150 g/mm by itself, without the F-P etalon, we obtained a best-case regular Raman spectral linewidth of 44 cm−1 for the characteristic Raman peak from a diamond sample. When we applied the SSR-RS technique to diamond, we obtained …

Nitrogen-doped carbon dots (NCDs) with an average diameter of 3.25 nm were prepared by a hydrothermal process from betel leaves as a single source of carbon and nitrogen. FTIR analysis attested to the presence of amine, carbonyl, and hydroxyl groups in the NCD surface. The obtained aqueous solutions were applied to enhance the growth of pepper and lettuce plants in a greenhouse and a growing room, respectively. The growth of these two plants was observed and analyzed at different stages, indicating significantly higher fresh and dry weights of roots and peppers, compared to the control. The healthy growth results from hydrophilic groups on the surface of the CDs, and the hydroxyl and carbonyl groups provide abundant binding sites for water molecules, which penetrate the plant along with NCDs. It promotes the absorption and utilization of water and nutrients via ROS, which leads to improved …

Interaction-free measurement (IFM) is a promising technique for low-dose detection and imaging, offering the unique advantage of probing an object with an overall reduced absorption of the interrogating photons. We propose an experiment to demonstrate IFM in the single x ray photon regime. The proposed scheme relies on the triple-Laue (LLL) symmetric x ray interferometer, where each Laue diffraction acts as a lossy beam splitter. In contrast to many quantum effects which are highly vulnerable to loss, we show that an experimental demonstration of this effect in the x ray regime is feasible and can achieve detection with reduced dose and high IFM efficiency even in the presence of substantial loss in the system. The latter aspect is claimed to be a general property of IFM based on our theoretical analysis. We scrutinize two suitable detection schemes that offer a dose reduction of up to half compared with direct …

Sodium-ion batteries (SIBs) are considered as the most promising complementary energy storage system for large-scale application due to the high abundance of sodium. However, the irreversible phase transition and slow diffusion kinetics in O3-type layered transition metals oxides cathodes impede the development of advanced SIBs. Here we address this issue by introducing high-entropy doping regulation strategies, a series of NaNi0.4Mn0.3-xFe0.1Ti0.1SnxLi0.05Sb0.05O2 cathodes exhibit an excellent rate performance (>60 mAh g−1 at 6 A g−1) and prolonged cycle performance (capacity retention >80 % after 300 cycles, at 120 mA g−1). The correlations between the chemical compositions and the electrochemical properties in the designed high-entropy transition metal oxides cathodes were elucidated using a combination of analytical tools including all kinds of electrochemical techniques including …

Identifying inexpensive, efficient, and highly stable alternative electrocatalysts for the methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER) is important. Here, Pt/WC anchored carbon nanotubes (Pt/WC@C) composites were prepared by single-step Reaction under Autogenic Pressure at Elevated Temperature (RAPET) technique at 800 °C, 900 °C, 1000 °C, and 1100 °C to realize the importance of MOR and HER activity. Among these, Pt/WC@C-900 demonstrates superior HER performance through the Volmer-Tafel mechanism with a low overpotential of 79 mV, a Tafel slope of 30 mV/dec, and better stability due to nanostructured Pt and WC particles as confirmed by High resolution transmission electron microscopy (HRTEM) analysis and the structural defects in the carbon nanotube as confirmed by Raman spectra. Conversely, Pt/WC@C-1000 exhibits outstanding MOR activity …

Magnetic polymeric conduits are developing as revolutionary materials in regenerative medicine, providing exceptional benefits in directing tissue healing, improving targeted medication administration, and facilitating remote control via external magnetic fields. The present article offers a thorough examination of current progress in the design, construction, and functionalization of these hybrid systems. The integration of magnetic nanoparticles into polymeric matrices confers distinctive features, including regulated alignment, improved cellular motility, and targeted medicinal delivery, while preserving structural integrity. Moreover, the incorporation of multifunctional attributes, such as electrical conductivity for cerebral stimulation and optical characteristics for real-time imaging, expands their range of applications. Essential studies indicate that the dimensions, morphology, surface chemistry, and composition of magnetic nanoparticles significantly affect their biocompatibility, degrading characteristics, and overall efficacy. Notwithstanding considerable advancements, issues concerning long-term biocompatibility, biodegradability, and scalability persist, in addition to the must for uniform regulatory frameworks to facilitate clinical translation. Progress in additive manufacturing and nanotechnology is overcoming these obstacles, facilitating the creation of dynamic and adaptive conduit structures designed for particular biomedical requirements. Magnetic polymeric conduits, by integrating usefulness and safety, are set to transform regenerative therapies, presenting a new avenue for customized medicine and advanced healthcare solutions.

Suspended (“free-standing”) graphene samples were irradiated with noble gas ions at varying energies, while maintaining a constant ion velocity. The resulting defect formation was analyzed using Raman spectroscopy. This process is attributed to the combined effects of nuclear and electronic mechanisms. While the efficiency coefficient (yield) is determined based on calculations for the nuclear mechanism, experimental results reveal that the defect concentration remains consistent for ions of different masses but identical velocities. This observation is interpreted as evidence of the electronic mechanism's contribution to defect formation, where the energy transferred to the graphene lattice primarily depends on the ion's velocity through the lattice rather than its mass.The results of the study show that increasing ion velocity leads to larger defect structures, providing a controllable approach for tuning defect size in …

Researchers have been investigating the physical and morphological properties of biodegradable polymer and copolymer films, blending them with other chemicals to solve challenges in medical, industrial, and eco-environmental fields. The present study introduces a novel, straightforward method for preparing biodegradable hydrogels based on polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) for medical applications. The resulting PVA/PVP-based hydrogel uniquely combines the water absorbency, biocompatibility, and biodegradability of the polymer composite. For hygiene products and medical uses, such as wound healing, hydrogen peroxide (HP) was encapsulated in the PVA/PVP hydrogels for controlled release application. Incorporating PVP into PVA significantly enhances the hydrogel water absorbency and improves the mechanical properties. However, to mitigate the disadvantage of high water absorbency which could result in undesired early dissolution, efforts were made to increase the water resistance and the mechanical characteristics of these hydrogels using freeze–thaw (F/T) cycles and chemical crosslinking PVA chains with trisodium trimetaphosphate (STMP). The resulting hydrogels serve as environmentally friendly bio-based polymer blends, broadening their applications in medical and industrial products. The structural and morphological properties of the hydrogel were characterized using Fourier transform infrared spectroscopy (FTIR), environmental scanning electron microscope analysis (E-SEM), and water-swelling tests. The HP controlled release rate was evaluated through kinetic release experiments using …

The chemistry of the electrolyte solutions that enable reversible Mg deposition is not trivial. Such solutions are currently limited to ethereal solvents and most of them contain chlorides complexes. These ionic complexes have important role in the performance. However, the presence of chlorides in these solutions complicates the cathode side because such solutions are not compatible with the commonly used metallic current collectors for cathodes. Consequently, it is questionable whether it is possible to synthesize fully functional Cl-free electrolyte solutions suitable commercial Mg-ion batteries. Noked et al. reported that by adding DME to the precursor electrolyte [Mg2Cl3*6THF]+ [Ph3AlCl]- in THF, it was possible to create a new electroactive complex Mg salt, namely, [Mg-3.DME]2+ 2[AlPh3Cl]-, which solution performs better than the precursor’s solution. This solution introduces a new case of chlorides free …

Saccharomyces cerevisiae, a model eukaryotic organism with a rich history in research and industry, has become a pivotal tool for studying Adenosine Deaminase Acting on RNA (ADAR) enzymes despite lacking these enzymes endogenously. This chapter reviews the diverse methodologies harnessed using yeast to elucidate ADAR structure and function, emphasizing its role in advancing our understanding of RNA editing. Initially, Saccharomyces cerevisiae was instrumental in the high-yield purification of ADARs, addressing challenges associated with enzyme stability and activity in other systems. The chapter highlights the successful application of yeast in high-throughput screening platforms that identify key structural motifs and substrate preferences of ADARs, showcasing its utility in revealing complex enzyme mechanics. Furthermore, we discuss the development of yeast-based systems to optimize guide …