BINA

Bilayer graphene exhibits a rich phase diagram in the quantum Hall regime, arising from a multitude of internal degrees of freedom, including spin, valley, and orbital indices. The variety of fractional quantum Hall states between filling factors suggests, among other things, a quantum phase transition between valley-unpolarized and polarized states at a perpendicular electric field . We find the behavior of with changes markedly as is reduced. At , may even vanish when is sufficiently small. We present a theoretical model for lattice-scale interactions which explains these observations; surprisingly, both repulsive and attractive components in the interactions are required. Within this model we analyze the nature of the state as a function of the magnetic and electric fields, and predict that valley-coherence may emerge for in the high regime. This suggests the system supports Kekule bond-ordering, which could in principle be verified via STM measurements.

Photocatalysts for seawater splitting are severely restricted because of the presence of multiple types of ions in seawater that cause corrosion and deactivation. As a result, new materials that promote adsorption of H+ and hinder competing adsorption of metal cations should enhance utilization of photogenerated electrons on the catalyst surface for efficient H2 production. One strategy to design advanced photocatalysts involves introduction of hierarchical porous structures that enable fast mass transfer and creation of defect sites that promote selective hydrogen ion adsorption. Herein, we used a facile calcination method to fabricate the macro–mesoporous C3N4 derivative, VN-HCN, that contains multiple nitrogen vacancies. We demonstrated that VN-HCN has enhanced corrosion resistance and elevated photocatalytic H2 production performance in seawater. Experimental results and theoretical calculations …

Plant-derived carbon dots have superior light absorption and intrinsic fluorescence properties. In this work, we have prepared nitrogen-doped carbon dots (N-CDs) from Piper betle leaves using a simple hydrothermal method. The synthesized N-CDs were characterized by various techniques such as high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, and photoluminescence. The N-CDs further proved to have systemic effects on the growth of strawberries compared with irrigating the strawberry plants with water and regular nutrients. The strawberry plants treated with N-CDs exhibited an increase in chlorophyll content of about 24.7%, which was reflected in increased carbohydrate content of approximately 48.61% compared to control plants. Also, N-CD-treated strawberry plants showed increased secondary metabolites (phenolics) compared to control …

Two-dimensional (2D) halide perovskites, HaPs, can provide chemical stability to three-dimensional (3D) HaP surfaces, protecting them from exposure to ambient species and from reacting with contacting layers. Both actions occur with 2D HaPs, with the general stoichiometry R2PbI4 (R: long or bulky organic amine) covering the 3D ones. Adding such covering films can also boost power conversion efficiencies of photovoltaic cells by passivating surface/interface trap states. For maximum benefit, we need conformal ultrathin and phase-pure (n = 1) 2D layers to enable efficient tunneling of photogenerated charge carriers through the 2D film barrier. Conformal coverage of ultrathin (<10 nm) R2PbI4 layers on 3D perovskites is challenging with spin coating; even more so is its upscaling for larger-area devices. We report on vapor-phase cation exchange of the 3D surface with the R2PbI4 molecules and real-time in situ …

Interdependent networks display many interesting properties, but have not been studied in laboratory experiments because of the lack of a platform that manifests appropriate couplings. Now, a network of disordered superconductors accomplishes this.

We present a miniature, ultra-sensitive magnetic field gradiometer in the form of a single elliptical planar Hall effect sensor that allows measuring magnetic field at 9 different locations on a 4 mm length scale [1]. The gradiometer detects magnetic field gradients with equivalent gradient magnetic noise levels of , and Hz at 0.1, 1, 10, and 50 Hz, respectively, and tested under ambient conditions by measuring the field gradient produced by an electric current flowing through a straight wire. The compact size, low noise level, versatility, simple design, and low cost of this gradiometer makes it a suitable choice for detecting magnetic field gradients in small, confined spaces such as current probes or wearable electronic medical devices.

The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is scheduled to be launched to geostationary orbit in 2026. It will carry a telescope with an unprecedentedly large field of view (204 deg) and NUV (230-290nm) sensitivity (22.5 mag, 5, at 900s). ULTRASAT will conduct the first wide-field survey of transient and variable NUV sources and will revolutionize our ability to study the hot transient universe: It will explore a new parameter space in energy and time-scale (months long light-curves with minutes cadence), with an extra-Galactic volume accessible for the discovery of transient sources that is 300 times larger than that of GALEX and comparable to that of LSST. ULTRASAT data will be transmitted to the ground in real-time, and transient alerts will be distributed to the community in 15 min, enabling a vigorous ground-based follow-up of ULTRASAT sources. ULTRASAT will also provide an all-sky NUV image to 23.5 AB mag, over 10 times deeper than the GALEX map. Two key science goals of ULTRASAT are the study of mergers of binaries involving neutron stars, and supernovae: With a large fraction (50%) of the sky instantaneously accessible, fast (minutes) slewing capability and a field-of-view that covers the error ellipses expected from GW detectors beyond 2025, ULTRASAT will rapidly detect the electromagnetic emission following BNS/NS-BH mergers identified by GW detectors, and will provide continuous NUV light-curves of the events; ULTRASAT will provide early (hour) detection and continuous high (minutes) cadence NUV light curves for hundreds of core-collapse supernovae, including for rarer supernova …

Speckle pattern analysis become a widespread method for remote sensing of various biomedical parameters. This technique is based on tracking the secondary speckle patterns reflected from a human skin illuminated by a laser beam. Speckle pattern variations can be translated into the corresponding partial carbon dioxide (CO 2) state (High or Normal) in the bloodstream. We present a novel approach for remote sensing of human blood carbon dioxide partial pressure (PCO 2) based on speckle pattern analyses combined with machine learning approach. The blood CO 2 partial pressure is an important indicative parameter for a variety of malfunctions in the human body.

This paper aims to present initial proof of concept of a non-invasive early diagnostic tool for Alzheimer disease (AD). The approach is based on the identification using Raman spectroscopy and machine learning algorithms of two proteins that are linked with AD and exist in the cerebrospinal fluid (CSF). As demonstrated in previous studies, the concentration of the proteins amyloid-β and tau may indicate the existence of AD. The proteins’ concentration in the CSF signifies the condition of AD. The current study can contribute to the existing body of knowledge by enabling the development of a non-invasive diagnostic tool that may help with early diagnosis of AD.

Rechargeable Zn-air batteries (RZABs) with non-alkaline electrolytes are a promising type of energy storage devices that potentially combine low cost, high energy density and safety. However, cathode materials for these devices remain poorly developed. We present a systematic study of how structure of carbons affects their performance as cathode scaffolds in non-alkaline RZABs. Ten commercially available types of carbon are characterized and tested in Zn-air battery cathodes with 1M Zn(OAc)2 or ZnSO4 solutions in H2O as electrolytes. At a low current density (0.1 mA cm−2), there is a roughly linear dependence between the roundtrip energy efficiency and the logarithm of BET surface area, and this dependence is relevant across materials with different morphology and graphitization degree. Lower overpotentials at the initial cycles are observed for cathodes that are more hydrophilic. At higher currents (1 mA …

Myopia (nearsightedness) and presbyopia (aging eye) are the most common refractive errors of the human eye. Technology has advanced toward correcting aberration using various surgical procedures, including laser surgery, as well as prescribing corrective lenses. Hence, the effect of various laser wavelengths on the eye has been extensively studied over the last few decades. Usually, excimer lasers are used for this purpose, which increases the cost of the procedure because they are unique and difficult to manufacture and require regular maintenance. Due to the absorption properties, visible wavelengths do not interact with the corneal layers and hence are currently not used for eye surgery. This study presents the first clinical evidence that a 532 nm laser in combination with an eye-safe fluorescein dye that is in wide clinical use in ophthalmology can be utilized for high-precision ablation purposes due to the …

Enhancing the image quality of the captured image is one of the prime objectives of modern image acquisition systems. These imaging systems can be broadly divided into two subsystems: an optical subsystem and a digital subsystem. There are various limitations associated with the optical and digital subsystems. One of the crucial parameters that are affected by the limitation of the physical extent of the recording or capturing system is the field of view (FOV). A reduced FOV can lead to loss of information thereby increasing the time for post-processing of images as well as introducing mechanical scanning to achieve a larger FOV. A simple yet efficient technique for FOV enhancement is demonstrated in this paper. An optical element is designed in such a way that it diffracts different wavelengths in the desired manner and the information from different regions of the object is carried by different wavelengths which …

Proteinoids—simple polymers composed of amino acids—were suggested decades ago by Fox and coworkers to form spontaneously by heat. These special polymers may self-assemble in micrometer structures called proteinoid microspheres, presented as the protocells of life on earth. Interest in proteinoids increased in recent years, in particular for nano-biomedicine. They were produced by stepwise polymerization of 3–4 amino acids. Proteinoids based on the RGD motif were prepared for targeting tumors. Nanocapsules form by heating proteinoids in an aqueous solution and slowly cooling to room temperature. Proteinoid polymers and nanocapsules suit many biomedical applications owing to their non-toxicity, biocompatibility and immune safety. Drugs and/or imaging reagents for cancer diagnostic, therapeutic and theranostic applications were encapsulated by dissolving them in aqueous proteinoid solutions. Here, recent in vitro and in vivo studies are reviewed.

Platinum group metal‐free catalysts have been considered the most promising alternative for platinum‐based catalysts for the oxygen reduction reaction in fuel cells. Despite the significant advancement made in activity, their viability as fuel cell catalysts is still questionable due to their low durability. So far, deciphering the degradation mechanisms of this class of catalysts has been hampered by their undefined structure. Herein, we used a molecular model catalyst, iron‐phthalocyanine, featuring Fe−N4 active sites with resemblance to those in the more active Fe−N−C catalysts, and studied their degradation mechanisms. Based on X‐ray photoelectron spectroscopy and the electrochemical measurements, three main demetallation processes were identified: at potentials higher than 0.65 V vs. RHE, where the metal center is Fe3+, an electrochemical oxidation of the ligand ring is occurring, between 0.6 and 0.2 V …

This paper presents a structured illumination microscopy (SIM) reconstruction algorithm that allows the reconstruction of super-resolved images with 2N + 1 raw intensity images, with N being the number of structured illumination directions used. The intensity images are recorded after using a 2D grating for the projection fringe and a spatial light modulator to select two orthogonal fringe orientations and perform phase shifting. Super-resolution images can be reconstructed from the five intensity images, enhancing the imaging speed and reducing the photobleaching by 17%, compared to conventional two-direction and three-step phase-shifting SIM. We believe the proposed technique will be further developed and widely applied in many fields.

Photonic crystals and metamaterials are two overarching paradigms for manipulating light. By combining these approaches, hypercrystals can be created, which are hyperbolic dispersion metamaterials that undergo periodic modulation and mix photonic-crystal-like aspects with hyperbolic dispersion physics. Despite several attempts, there has been limited experimental realization of hypercrystals due to technical and design constraints. In this work, hypercrystals with nanoscale lattice constants ranging from 25 to 160 nm were created. The Bloch modes of these crystals were then measured directly using scattering near-field microscopy. The dispersion of the Bloch modes was extracted from the frequency dependence of the Bloch modes, revealing a clear switch from positive to negative group velocity. Furthermore, spectral features specific to hypercrystals were observed in the form of sharp density of states peaks …

Myopia (nearsightedness) and presbyopia (aging eye) are the most common refractive errors of the human eye. Technology has advanced toward correcting aberration using various surgical procedures, including laser surgery, as well as prescribing corrective lenses. Hence, the effect of various laser wavelengths on the eye has been extensively studied over the last few decades. Usually, excimer lasers are used for this purpose, which increases the cost of the procedure because they are unique and difficult to manufacture and require regular maintenance. Due to the absorption properties, visible wavelengths do not interact with the corneal layers and hence are currently not used for eye surgery. This study presents the first clinical evidence that a 532 nm laser in combination with an eye-safe fluorescein dye that is in wide clinical use in ophthalmology can be utilized for high-precision ablation purposes due to the …

Polymer Electrolyte Membrane Fuel Cells (PEMFC) are currently considered the most advanced fuel cell technology. However, the industrial implementation of PEMFCs is strongly hindered by deficient durability, especially that of the carbonaceous materials commonly used to support the platinum-based catalyst nanoparticles, which are prone to electrochemical corrosion at the cathode, resulting in a serious performance loss of the entire cell. In the attempt to overcome this issue, many research groups have tried to introduce heteroatoms (N, S, B, P) into the carbon lattice, thus trying to make the electrode corrosion-resistant. Newly developed heteroatom-doped carbons were subjected to corrosion tests in half-cell and single-cell systems to evaluate their stability. This paper reviews the recent studies devoted to corrosion research of heteroatom-doped carbon supports for Pt-based catalysts in PEMFCs. In particular, an overview on N, B, and S dopants and their effects on carbon corrosion is provided.

We study non-normalizable quasi-equilibrium states (NNQE) arising from anomalous diffusion. Initially, particles in contact with a thermal bath are released from an asymptotically flat potential well, with dynamics that is described by fractional calculus. For temperatures that are sufficiently low compared to the potential depth, the properties of the system remain almost constant in time. We use the fractional-time Fokker-Planck equation (FTFPE) and continuous-time random walk approaches to calculate the ensemble averages of observables. We obtain analytical estimates of the duration of NNQE, depending on the fractional order, from approximate theoretical solutions of the FTFPE. We study and compare two types of observables, the mean square displacement typically used to characterize diffusion, and the thermodynamic energy. We show that the typical time scales for stagnation depend exponentially on the activation energy in units of temperature multiplied by a function of the fractional exponent.

Current Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) using short-read sequencing strategies resolve expressed Ab transcripts with limited resolution of the C region. In this article, we present the near-full-length AIRR-seq (FLAIRR-seq) method that uses targeted amplification by 5'RACE, combined with single-molecule, real-time sequencing to generate highly accurate (99.99%) human Ab H chain transcripts. FLAIRR-seq was benchmarked by comparing H chain V (IGHV), D (IGHD), and J (IGHJ) gene usage, complementarity-determining region 3 length, and somatic hypermutation to matched datasets generated with standard 5'RACE AIRR-seq using short-read sequencing and full-length isoform sequencing. Together, these data demonstrate robust FLAIRR-seq performance using RNA samples derived from PBMCs, purified B cells, and whole blood, which recapitulated results generated by commonly used methods, while additionally resolving H chain gene features not documented in IMGT at the time of submission. FLAIRR-seq data provide, for the first time, to our knowledge, simultaneous single-molecule characterization of IGHV, IGHD, IGHJ, and IGHC region genes and alleles, allele-resolved subisotype definition, and high-resolution identification of class switch recombination within a clonal lineage. In conjunction with genomic sequencing and genotyping of IGHC genes, FLAIRR-seq of the IgM and IgG repertoires from 10 individuals resulted in the identification of 32 unique IGHC alleles, 28 (87%) of which were previously uncharacterized. Together, these data demonstrate the capabilities of FLAIRR-seq to characterize …

Genome engineering via targeted nucleases, specifically CRISPR-Cas9, has revolutionized the field of gene therapy research, providing a potential treatment for diseases of the blood and immune system. While numerous genome editing techniques have been used, CRISPR-Cas9 homology-directed repair (HDR)-mediated editing represents a promising method for the site-specific insertion of large transgenes for gene knock-in or gene correction. Alternative methods, such as lentiviral/gammaretroviral gene addition, gene knock-out via non-homologous end joining (NHEJ)-mediated editing, and base or prime editing, have shown great promise for clinical applications, yet all possess significant drawbacks when applied in the treatment of patients suffering from inborn errors of immunity or blood system disorders. This review aims to highlight the transformational benefits of HDR-mediated gene therapy and possible solutions for the existing problems holding the methodology back. Together, we aim to help bring HDR-based gene therapy in CD34+ hematopoietic stem progenitor cells (HSPCs) from the lab bench to the bedside.