BINA

Although direct methanol fuel cells (DMFCs) have been spotlighted in the past decade, their commercialization has been hampered by the poor efficiency of the methanol oxidation reaction (MOR) due to the unsatisfactory performance of currently available electrocatalysts. Herein, we developed a binder-free, copper-based, self-supported electrode consisting of a heterostructure of Cu3P and mixed copper oxides, i.e., cuprous–cupric oxide (Cu-O), as a high-performance catalyst for the electro-oxidation of methanol. We synthesized a self-supported electrode composed of Cu-O|Cu3P using a two-furnace atmospheric pressure–chemical vapor deposition (AP-CVD) process. High-resolution transmission electron microscopy analysis revealed the formation of 3D nanocrystals with defects and pores. Cu-O|Cu3P outperformed the MOR activity of individual Cu3P and Cu-O owing to the synergistic interaction between them. Cu3P|Cu-O exhibited a highest anodic current density of 232.5 mAcm−2 at the low potential of 0.65 V vs. Hg/HgO, which is impressive and superior to the electrocatalytic activity of its individual counterparts. The formation of defects, 3D morphology, and the synergistic effect between Cu3P and Cu-O play a crucial role in facilitating the electron transport between electrode and electrolyte to obtain the optimal MOR activity. Cu-O|Cu3P shows outstanding MOR stability for about 3600 s with 100% retention of the current density, which proves its robustness alongside CO intermediate.

Corrosion resistance, porous structure and high surface area are becoming more and more significant as electrode properties in long-term operation of polymer electrolyte membrane fuel cell. In this work, high surface area, porous titanium-based ceramic compound was synthesized via the facile modified urea glass method (mUGM) and utilized as electrocatalyst support for oxygen resection reaction (ORR) in fuel cells cathodes. The as-prepared compound was found to have surface area and crystallite sizes of the scale of carbon black (CB) with strong dependency on the Ti precursor to urea molar ratio. N–C bonds were found to be involved, as suggested from the X-ray photoelectron spectra, and little to-no residual bulk carbon was found in the samples (X-ray diffraction and Raman spectroscopy). After deposition of Pt metal catalyst, the ceramic-based system demonstrated superior ORR activity and fuel cell …

Introduced here are new hybrid benzocorrole ligands, displaying both the cavity size of corroles and the dianionic character of porphyrins. Nonaromatic and yet sporting deceptively porphyrin-like optical spectra, they are readily accessible via a simple three-step synthetic protocol.

Fer and its sperm and cancer specific variant, FerT, are non-receptor tyrosine kinases which play roles in cancer progression and metastasis. Recent studies have shed light on the regulatory role of these kinases in ensuring proper sperm function. Comparison of the regulatory cascades in which Fer and FerT are engaged in sperm and cancer cells presents an interesting picture, in which similar regulatory interactions of these enzymes are integrated in a similar or different regulatory context in the two cell types. These diverse compositions extend from the involvement of Fer in modulation of actin cytoskeleton integrity and function, to the unique regulatory interactions of Fer with PARP-1 and the PP1 phosphatase. Furthermore, recent findings link the metabolic regulatory roles of Fer and FerT in sperm and cancer cells. In the current review, we discuss the above detailed aspects, which portray Fer and FerT as new regulatory links between sperm and malignant cells. This perspective view can endow us with new analytical and research tools that will deepen our understanding of the regulatory trajectories and networks that govern these two multi-layered systems.

A deep learning network requires high-performance computer systems for solving complex problems with millions of parameters. In our lab, we develop a fully optical machine learning system that is based on the nonlinear four wave mixing process in multimode fibers. We exploit the optical nonlinear interactions between waves for developing a deep learning system faster than electronic based systems. finally, we resort to quantum light for realizing quantum deep learning system, which can bring the deep learning techniques to the quantum field. In this talk, we will present details of our novel system and discuss our preliminary results.

Quantum interferometers are able to improve the sensitivity of classical interferometers beyond the shot-noise limit. This is done by employing squeezed states of light and destructive interference of the noise in the system. We developed a quantum SU(1,1) interferometer in the time domain. Our nonlinear quantum interferometer creates interference of the input signals at different times and frequencies. We can control the time and frequency differences for investigating the full temporal and spectral structure of the signal. This quantum interferometer can be utilized for sensing ultrafast phase changes, quantum imaging, temporal mode encoding, and studying the temporal structure of entangled photons.

The Aharonov-Bohm effect is a fundamental topological phenomenon with a wide range of applications. It consists of a charge encircling a region with a magnetic flux in a superposition of wave packets having their relative phase affected by the flux. In this work we analyze this effect using an entropic measure known as realism, originally introduced as a quantifier of a system's degree of reality and mathematically related to notions of global and local quantum coherence. More precisely, we look for observables that lead to gauge-invariant realism associated with the charge before it completes its loop. We find that the realism of these operators has a sudden change when the line connecting the center of both wave packets crosses the solenoid. Moreover, we consider the case of a quantized magnetic-field source, pointing out similarities and differences between the two cases. Finally, we discuss some …

We report the observation of coherent oscillations in conversion efficiency of weakly bound dimers formed from a thermal gas of ultracold atoms. Finite thermal energy of the gas causes loss of coherence when a broad continuum is resonantly coupled to a discrete bound state. Restoration of the coherence can be achieved through nonadiabatic transitions of the dressed molecular energy level that are induced by a strong modulation pulse with fast envelope dynamics. Conditions to observe coherent oscillations are verified and control of their properties is demonstrated. The main experimental findings are supported by theoretical modeling and numerical calculations. The observed results may lead to a renewed interest in general studies of a discrete energy level coupled to a broadband continuum when the properties of both are fully controlled.

We study the effects of electrostatic gating on the lateral distribution of charge carriers in two dimensional devices, in a non-linear dielectric environment. We compute the charge distribution using the Thomas-Fermi approximation to model the electrostatics of the system. The electric field lines generated by the gate are focused at the edges of the device, causing an increased depletion near the edges, compared to the center of the device. This effect strongly depends on the dimensions of the device, and the non-linear dielectric constant of the substrate. We experimentally demonstrate this effect using scanning superconducting interference device (SQUID) microscopy images of current distributions in gated LaAlO/SrTiO heterostructures.

Sending an ultrafast pulse in multimode fiber can lead to nonlinear interactions between the modes. When sending such a pulse in graded-index fibers there are cases where all the energy is transferring from the high-order modes into the lowest one. This effect is called modal self-cleaning. We developed a multimode time-lens, which measures the temporal and spatial dynamics of ultrafast signals in multimode fibers. With our system, we can detect the dynamics of each mode in time with high temporal resolution, and identify which mode is coupled to which and how the energy transfers between them. In this talk, We will present our measurement system in details and describe our novel results on modal self-cleaning. We will also comment on other multimode effects which our system can measure for the first time.

We present the first single-pair Bell inequality test, able to obtain a Bell parameter value for every entangled pair detected. After the measurements, each pair still presents a noteworthy amount of entanglement to be exploited for further quantum-protocols.

Time-lenses can image ultrafast signals in time. Placing them in a 2-f configuration leads to Fourier transform of the input signal and ultrafast spectroscopy. We utilized two time-lenses in a 4-f configuration and formed an interferometer in the time domain. Our time lenses are based on four-wave mixing process, generating an idler beam which serves as the output. The output from the first time-lens is the input to the second time-lens. At the output of the second time-lens, we get an interference between the signal beams of both time-lenses and the idler beams of both time-lenses. This interference is sensitive to ultrafast phase shifts in time and can lead to interfere signals in different times. This interferometer is good for quantum imaging, and studying the temporal structure of entangled photons. In this talk we will demonstrate the interferometer, how we exploit time-lenses for interferometry, the application of the …

The unique fluorescent nanomaterials known as carbon dots (CDs) are highly resistant to photobleaching, have low toxicity, and are well soluble in water. Polyethyleneimine (PEI) coated CDs are a novel fluorophore with good biocompatibility and pH sensing ability. Here, p-phenylenediamine (p-PD) is used as a carbon source and hyperbranched PEI is used as a surface passivation agent in a simple, one-step hydrothermal synthesis process. The CDs optical characteristics are pH-responsive due to the presence of different amine groups on PEI, which is functional polycationic polymer. The limits of techniques based on fluorescence intensity can be overcome by fluorescent lifetime imaging microscopy (FLIM), a very sensitive method for detecting a microenvironment. In this study, FLIM was used to measure pH with pH-sensitive CDs. These molecules are nontoxic to the cells, and the positively charged CDs have …

All‐solid‐state lithium batteries (ASSLBs) are considered as an alternative solution to lithium‐ion batteries, because of their safety and high theoretical energy density. Argyrodite‐based solid‐electrolytes (SEs), Li6PS5X (X = Cl, Cl0.5Br0.5 or Br), are promising candidates for ASSLBs. Most of the previous reports have used Li6PS5Cl as the default SE composition. Here, the electrochemical behavior of three different argyrodites with Cl− or Br−, or both, as the halogen is systematically studied. Using LiNi0.6Co0.2Mn0.2O2 as a model cathode, the behavior of these SEs in ASSLB cells is also studied. SEs containing Br show higher near‐room‐temperature ionic conductivity (>2 mS cm−1) and the critical current density (≥1 mA cm−2) during Li plating/stripping, and are stable up to 5 V versus Li/Li+. Li6PS5Br gives the best electrochemical performance in terms of C‐rate and long‐term cycling among the three …

Severe combined immunodeficiency (SCID) is a group of disorders caused by mutations in genes involved in the process of lymphocyte maturation and function. CRISPR-Cas9 gene editing of the patient’s own hematopoietic stem and progenitor cells (HSPCs) ex vivo could provide a therapeutic alternative to allogeneic hematopoietic stem cell transplantation, the current gold standard for treatment of SCID. To eliminate the need for scarce patient samples, we engineered genotypes in healthy donor (HD)-derived CD34+ HSPCs using CRISPR-Cas9/rAAV6 gene-editing, to model both SCID and the therapeutic outcomes of gene-editing therapies for SCID via multiplexed homology-directed repair (HDR). First, we developed a SCID disease model via biallelic knockout of genes critical to the development of lymphocytes; and second, we established a knockin/knockout strategy to develop a proof-of-concept single …

Geometry, an ancient yet vibrant branch of mathematics, has important and far-reaching impacts on various disciplines such as art, science, and engineering. Here, we introduce an emerging concept dubbed “geometric deep optical sensing” that is based on a number of recent demonstrations in advanced optical sensing and imaging, in which a reconfigurable sensor (or an array thereof) can directly decipher the rich information of an unknown incident light beam, including its intensity, spectrum, polarization, spatial features, and possibly angular momentum. We present the physical, mathematical, and engineering foundations of this concept, with particular emphases on the roles of classical and quantum geometry and deep neural networks. Furthermore, we discuss the new opportunities that this emerging scheme can enable and the challenges associated with future developments.

Protection from viral infections depends on immunoglobulin isotype switching, which endows antibodies with effector functions. Here, we find that the protein kinase DYRK1A is essential for B cell-mediated protection from viral infection and effective vaccination through regulation of class switch recombination (CSR). Dyrk1a-deficient B cells are impaired in CSR activity in vivo and in vitro. Phosphoproteomic screens and kinase-activity assays identify MSH6, a DNA mismatch repair protein, as a direct substrate for DYRK1A, and deletion of a single phosphorylation site impaired CSR. After CSR and germinal center (GC) seeding, DYRK1A is required for attenuation of B cell proliferation. These findings demonstrate DYRK1A-mediated biological mechanisms of B cell immune responses that may be used for therapeutic manipulation in antibody-mediated autoimmunity.

Fluorescence‐based imaging has an enormous impact on our understanding of biological systems. However, in vivo fluorescence imaging is greatly influenced by tissue scattering. A better understanding of this dependance can improve the potential of non‐invasive in vivo fluorescence imaging. In this paper we present a diffusion model, based on an existing master‐slave model, of isotropic point sources imbedded in a scattering slab, representing fluorophores within a tissue. The model was compared to Monte Carlo simulations and measurements of a fluorescent slide measured through tissue‐like phantoms with different reduced scattering coefficients (0.5 to 2.5mm‐1) and thicknesses(0.5 to 5mm). Results show a good correlation between our suggested theory, simulations and experiments; while the fluorescence intensity decays as the slab's scattering and thickness increase, the decay rate decreases as the …

The synchronization of human networks, and the possibility of obtaining an agreement in a group, are essential for our survival. The dynamics of human networks are affecting every aspect of our lives in politics, economics, science, and engineering, and are essential for our mental and physical health. We study the unique properties of human networks and their dynamics by resorting to coupled violin players. We found that the human ability to ignore inputs or to focus on an input change dramatically the dynamics of the network compared to other coupled networks. We show how human networks react to frustrating situations, how they change the network connectivity or the network coupling strength, and how they escape local minima. In addition, the formation of leaders has a significant impact on the dynamics of human groups and networks and can completely shift the trajectory of a society. We study how …

The most abundant form of RNA editing in metazoa is the deamination of adenosines into inosines (A-to-I), catalyzed by ADAR enzymes. Inosines are read as guanosines by the translation machinery, and thus A-to-I may lead to protein recoding. The ability of ADARs to recode at the mRNA level makes them attractive therapeutic tools. Several approaches for Site-Directed RNA Editing (SDRE) are currently under development. A major challenge in this field is achieving high on-target editing efficiency, and thus it is of much interest to identify highly potent ADARs. To address this, we used the baker yeast Saccharomyces cerevisiae as an editing-naïve system. We exogenously expressed a range of heterologous ADARs and identified the hummingbird and primarily mallard-duck ADARs, which evolved at 40–42°C, as two exceptionally potent editors. ADARs bind to double-stranded RNA structures (dsRNAs), which in turn are temperature sensitive. Our results indicate that species evolved to live with higher core body temperatures have developed ADAR enzymes that target weaker dsRNA structures and would therefore be more effective than other ADARs. Further studies may use this approach to isolate additional ADARs with an editing profile of choice to meet specific requirements, thus broadening the applicability of SDRE.