BINA

Efficient and stable electrocatalysts are critically needed for the development of practical overall seawater splitting. The nanocomposite of RuCoBO has been rationally engineered to be an electrocatalyst that fits these criteria. The study has shown that a calcinated RuCoBO-based nanocomposite (Ru2Co1BO-350) exhibits an extremely high catalytic activity for H2 and O2 production in alkaline seawater (overpotentials of 14 mV for H2 evolution and 219 mV for O2 evolution) as well as a record low cell voltage (1.466 V@10 mA cm–2) and long-term stability (230 h @50 mA cm–2 and @100 mA cm–2) for seawater splitting. The results show that surface reconstruction of Ru2Co1BO-350 occurs during hydrogen evolution reaction and oxygen evolution reaction, which leads to the high activity and stability of the catalyst. The reconstructed surface is highly resistant to Cl– corrosion. The investigation suggests that a new …

Invisibility cloaks for flexural waves have mostly been examined in a continuous-wave regime, while invisibility is likely to deteriorate for short pulses. Here, we propose the practical realization of a unidirectional invisibility cloak for flexural waves based on an area-preserving coordinate transformation. Time-resolved experiments reveal how the invisibility cloak deviates a pulsed plane wave from its initial trajectory and how the initial wavefront perfectly recombines behind the cloak, leaving the diamond-shaped hole invisible, notwithstanding the appearance of a forerunner. Three-dimensional full-elasticity simulations support our experimental observations.

The short time (large energy) behavior of the Sachdev-Ye-Kitaev model (SYK) is one of the main reasons for the growing interest garnered by this model. True chaotic behavior sets in at the Thouless time, which can be extracted from the energy spectrum. In order to do so, it is necessary to unfold the spectrum, ie, to filter out global tendencies. Using a simple ensemble average for unfolding results in a parametically low estimation of the Thouless energy. By examining the behavior of the spectrum as the distribution of the matrix elements is changed into a log-normal distribution, it is shown that the sample-to-sample level spacing variance determines this estimation of the Thouless energy. Using the singular value decomposition method, which filters out these global sample-to-sample fluctuations, the Thouless energy becomes parametrically much larger, essentially of the order of the band width. It is shown that the …

Biosensors are analytical devices with a wide range of uses in various fields such as food, military, environmental monitoring, and clinical diagnostics. Similarly, polymers and their composites have sparked a lot of interest in biosensing because of their properties, including compatibility with biological molecules, efficient electron transfer during biochemical reactions, bioreagent loading, and biomolecule immobilization. Different nanoparticles such as carbon nanotubes, graphenes, gold nanoparticles, etc., have been efficiently integrated into the polymer matrix to improve performance features such as rapid response, high selectivity, improved sensitivity, long-term stability, and lower detection limit. Polymers in combination with nanomaterials provide a three-dimensional matrix that preserves biomolecule activity and provides an excellent platform for immobilization due to their good durability, porosity, selectivity …

Particle hopping is a common feature in heterogeneous media. We explore such motion by using the widely applicable formalism of the continuous time random walk and focus on the statistics of rare events. Numerous experiments have shown that the decay of the positional probability density function P (X, t), describing the statistics of rare events, exhibits universal exponential decay. We show that such universality ceases to exist once the threshold of exponential distribution of particle hops is crossed. While the mean hop is not diverging and can attain a finite value; the transition itself is critical. The exponential universality of rare events arises due to the contribution of all the different states occupied during the process. Once the reported threshold is crossed, a single large event determines the statistics. In this realm, the big jump principle replaces the large deviation principle, and the spatial part of the decay is unaffected by the temporal properties of rare events.

Large grid energy storage devices are critical for the success of the clean and sustainable energy revolution. As Li-ion batteries are earmarked for electric vehicles and portable devices such as laptops and cellphones, other electrochemical systems should be developed that enable cost-effective, safe, and durable large-scale energy storage. Due to the low cost and non-flammability of aqueous electrolyte solutions, much effort is being put into the development of ‘beyond-Li’ batteries and super capacitors that can work in these environments. Here, we propose new proton batteries comprising an acetic acid electrolyte solution, NiII [FeIII(CN)6]2/3·4H2O Prussian blue analog cathodes, and Ti3C2Tx MXene anodes. Both electrodes were investigated independently to discover ideal settings for the electrochemical performance and stability. Significant attention was given to the cathodes' protons storage mechanism. In …

Barrett’s esophagus (BE) is an adaptive response of the lower esophagus to recurring exposure to gastroesophageal reflux that leads to intestinal metaplasia and/or gastric metaplasia depending on the specific criteria in each country. 1 The tissue microenvironment and local resident fibroblasts are critically involved in tissue homeostasis and repair processes 2; however, the involvement of stromal-derived fibroblasts in BE and, in particular, their involvement in rare instances of metaplastic transformation and progression to esophageal adenocarcinoma (EAC) are poorly understood. To examine this, we have leveraged a human organ-on-a-chip (Organ Chip) microfluidic culture methodology 3 to construct tissue recombinant models containing esophageal epithelial cells isolated from organoids derived from multiple BE patients (Figure A1A and B and Table) interfaced with fibroblasts isolated from normal …

Metal transcription factors regulate metal concentrations in eukaryotic and prokaryotic cells. Copper is a metal ion that is being tightly regulated, owing to its dual nature. Whereas copper is an essential nutrient for bacteria, it is also toxic at high concentrations. CopY is a metal-sensitive transcription factor belonging to the copper-responsive repressor family found in Gram-positive bacteria. CopY represses transcription in the presence of Zn(II) ions and initiates transcription in the presence of Cu(I) ions. The complete crystal structure of CopY has not been reported yet, therefore most of the structural information on this protein is based on its similarity to the well-studied MecI protein. In this study, electron paramagnetic resonance (EPR) spectroscopy was used to characterize structural and local dynamical changes in Streptococcus pneumoniae CopY as a function of Zn(II), Cu(I), and DNA binding. We detected different …

Copper chalcogenides are materials characterized by intrinsic doping properties, allowing them to display high carrier concentrations due to their defect‐heavy structures, independent of the preparation method. Such high doping enables these materials to display plasmonic resonances, tunable by varying their stoichiometry. Here, plasmonic dynamics is studied in drop‐cast Cu9S5 (digenite) nanocrystals (NCs) film using ultrafast pump–probe spectroscopy. The NCs are synthesized by thermal annealing of copper foil using chemical vapor deposition (CVD), followed by sonication and drop‐casting of the isolated few‐layered flakes on different substrates. The samples display a broad localized surface plasmon resonance (LSPR) in the near‐infrared (NIR), peaking at 2100 nm. The free carrier response is further confirmed by fitting the linear absorption with a Drude–Lorentz effective medium approximation model …

The electrocatalytic CO2 reduction in aqueous solution mainly involves bond cleavage and formation between C, H and O, and it is highly desirable to expand the bond formation reaction of C with other atoms to obtain novel and valuable chemicals. The electrochemical synthesis of N-containing organic chemicals in electrocatalytic CO2 reduction via introducing N sources is an effective strategy to expand the product scope, since chemicals containing C–N bonds (e.g. amides and amines) are important reactants/products for medicine, agriculture and industry. This article focuses on the research progress of C–N coupling from CO2 and inorganic nitrogenous species in aqueous solution. Firstly, the reaction pathways related to the reaction intermediates for urea, formamide, acetamide, methylamine and ethylamine are highlighted. Then, the electrocatalytic performance of different catalysts for these several N …

During embryonic development, mutually antagonistic signaling cascades determine gonadal fate toward a testicular or ovarian identity. Errors in this process result in disorders of sex development (DSDs), characterized by discordance between chromosomal, gonadal, and anatomical sex. The absence of an appropriate, accessible in vitro system is a major obstacle in understanding mechanisms of sex-determination/DSDs. Here, we describe protocols for differentiation of mouse and human pluripotent cells toward gonadal progenitors. Transcriptomic analysis reveals that the in vitro–derived murine gonadal cells are equivalent to embryonic day 11.5 in vivo progenitors. Using similar conditions, Sertoli-like cells derived from 46,XY human induced pluripotent stem cells (hiPSCs) exhibit sustained expression of testis-specific genes, secrete anti-Müllerian hormone, migrate, and form tubular structures. Cells derived …

Integration of information over the central nervous system is an important neural process that affects our ability to perceive and react to the environment. The visual system is required to continuously integrate information arriving from two different sources (the eyes) to create a coherent percept with high spatiotemporal precision. Although this neural integration of information is assumed to be critical for visual performance, it can be impaired under some pathological or developmental conditions. Here we took advantage of a unique developmental condition, amblyopia (“lazy eye”), which is characterized by an impaired temporal synchronization between the two eyes, to meticulously study the effect of synchronization on the integration of binocular visual information. We measured the eyes’ asynchrony and compensated for it (with millisecond temporal resolution) by providing time-shifted stimuli to the eyes. We found …

The increasing interest and need to shift to sustainable energy give rise to the utilization of fuel cell technologies in various applications. The challenging task of hydrogen storage and transport led to the development of liquid hydrogen carriers (LHCs) as fuels for direct LHC fuel cells, such as methanol in direct methanol fuel cells (DMFCs). Although simpler to handle, most direct LHC fuel cells suffer from durability and price issues derived from high catalysts’ loadings and byproducts of the oxidation reaction of the fuel. Herein, we report on the development of direct hydroquinone fuel cells (DQFCs) based on anthraquinone-2,7-disulfonic acid (AQDS) as an LHC. We have shown that DQFC can operate with a continuous flow of quinone as a hydrogen carrier, outperforming the incumbent state-of-the-art DMFC by a factor of 3 in peak power density while completely removing the need for any catalyst at the anode. In …

We demonstrate an improved YBa 2 Cu 3 O 7-δ-based microwave kinetic inductance detector with a quality factor and noise equivalent power, $\sim {10^{-12}}{\mkern 1mu}{\text {W}}{\mkern 1mu}{\sqrt {{\text {Hz}}}^{-1}} $ at 10 K. Zero field cooled (ZFC) and field cooled (FC) measurements of the magnetic field dependence of the resonance characteristics, show substantially different behavior, indicating that both the screening currents and vortices play a role. The ZFC measurements exhibit a sharp decrease of the resonance frequency, , and at low fields, up to the full penetration field, revealing the dominant role of the screening currents. In contrast, the FC measurements exhibit a moderate decrease of and with field, revealing the role of vortices and reflecting the field dependence of the penetration depth in a d-wave superconductor.

A hydrothermal method was conducted to synthesize Ni(1−α)Co(α)MoO4 (α = 0, 0.1, 0.3, and 0.5 M) nanorods, which were proven as excellent electrode materials in a hybrid supercapacitor. Their electrochemical properties were also dependent on the Ni/Co ratio as demonstrated by different electrochemical techniques. Ni0.5Co0.5MoO4 (α = 0.5 M) offered specific capacity (Qg) = 354 Cg–1@1 Ag–1, a remarkable specific capacity with a notable retention capacity of 92% after 8000 repeated cycles at 10 Ag–1. Ni0.5Co0.5MoO4 with a high surface area outperformed the mono-metallic (NiMoO4) and bimetallic (Ni0.9Co0.1MoO4 and Ni0.7Co0.3MoO4) nanostructures. The hybrid supercapacitor (Ni0.5Co0.5MoO4//activated carbon) delivered a maximum Qcell of 53 Cg–1 at 1 Ag–1 with an energy density of 16.2 Wh kg–1 and power density of 725 W kg–1.

Nanoporous metals possess unique properties attributed to their high surface area and interconnected nanoscale ligaments. They are mostly fabricated by wet synthetic methods that are not universal to various metals and not free from impurities due to solution-based etching processes. Here, we demonstrate that the plasma treatment of metal nanoparticles formed by physical vapor deposition is a general route to form such films with many metals including the non-noble ones. The resultant nanoporous metallic films are free of impurities and possess highly curved ligaments and nanopores. The metal films are ultrathin, yet remarkably robust and very well connected, and thus are highly promising for various applications such as transparent conducting electrodes.

This review describes the use of Electron Paramagnetic Resonance (EPR) to measure residue specific dynamics in proteins with a specific focus on Cu(II)‐based spin labels. First, we outline approaches used to measure protein motion by nitroxide‐based spin labels. Here, we describe conceptual details and outline challenges that limit the use of nitroxide spin labels to solvent‐exposed α‐helical sites. The bulk of this review showcases the use of newly developed Cu(II)‐based protein labels. In this approach, the strategic mutation of native residues on a protein to generate two neighboring Histidine residues (i.e., the dHis motif) is exploited to enable a rigid site‐selective binding of a Cu(II) complex. The chelation of the Cu(II) complex to dHis directly anchors the Cu(II) spin label to the protein backbone. The improvement in rigidity expands both the spin‐labeling toolkit as well as the resolution of many EPR …

A thorough understanding of biological species and emerging nanomaterials requires, among other efforts, their in-depth characterization through optical techniques capable of nanoresolution. Nanoscopy techniques based on tip-enhanced optical effects have gained tremendous interest over the past years, given their potential to obtain optical information with resolutions limited only by the size of a sharp probe interacting with focused light, irrespective of the illumination wavelength. Although their popularity and number of applications is rising, tip-enhanced nanoscopy (TEN) techniques still largely rely on probes that are not specifically developed for such applications, but for atomic force microscopy. This limits their potential in many regards, e.g., in terms of signal-to-noise ratio, attainable image quality, or extent of applications. We take the first steps toward next-generation TEN by demonstrating the fabrication …

Sonochemistry in now well recognized as a technique for the fabrication of nanomaterials. This is reflected in the many review articles on sonochemistry and nanoparticles that have been published over the last few years. It is so happened that Suslick, one of the forefathers of this field, has lately written a very comprehensive review on this topic (Bang, 2010). In his review, Suslick has summarized the work published on sonochemistry and nanomaterials until 2010. The current review will try to scan the work done in this area until the end of 2012. The current review will concentrate first on explaining why nano? Namely, when, why, and what kind of nanomaterials are produced upon the collapse of the acoustic bubble?

Hierarchical organic structures have gained vast attention in the past decade owing to their great potential in chemical and medical applications in industries such as the food and pharmaceutical industries. In this paper, the crystallization of L-glu hierarchical spheres using inorganic ions, namely calcium, barium and strontium cations, is described. The anti-solvent precipitation method is used for the spherical crystallization. The L-glu microspheres are characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo-electron microscopy (XPS) and polarized microscopy (POM). It is shown that without additives, L-glu crystallizes as flower-like structures, very different from the hierarchical spheres crystallized with the charged additives. Based on our results, we suggest a mechanism for the hierarchical sphere formation based on the crystallization and self-assembly of L-glu in emulsion droplets using charged additives.

A major challenge in radiation oncology is predicting and optimizing a clinical response on a personalized manner. Recently, nanotechnology-based cancer treatments are being combined with photodynamic therapy (PDT) and photothermal therapy (PTT). Machine learning predictive models can be used to optimize the clinical setup configuration, such as: laser radiation intensity, treatment duration, and nanoparticles features. In this work we demonstrate a methodology to find the optimized treatment parameters for PDT and PTT by collecting data of in vitro cytotoxicity assay of PDT/PTT-induced cell death using a single nanocomplex. We examine three machine learning prediction models of regression, interpolation, and low degree analytical function to predict the laser radiation intensity and duration that maximize the treatment efficiency. To examine these prediction models accuracy, we built a dedicated dataset for PDT, PTT, and a combined treatment that is based on cell death measurements after light radiation treatment, divided to training and test sets. The preliminary results show that all models offer sufficient performance with death rate error of 0.09, 0.15, and 0.12 for the regression, interpolation, and analytical function fitting. Nevertheless, the analytical function due to its simple form has a clinical application advantage that can be used for further sensitivity analysis of the treatment parameters on the performance. In all, the results of this work form a baseline for a future machine learning base personal prediction model in combined nanotechnology-based phototherapy cancer treatment.