BINA

Sunlight-driven photocatalysis is an environmentally friendly approach to solve ecological issues. The development of simple yet sufficiently stable photocatalytic materials capable of responding to the full-spectrum light remains challenging. Here, we demonstrate the phase transformations of bulk copper sulfides from digenite (Cu9S5) to djurleite (Cu1.97S) and low chalcocite (Cu2S) by the reactive thermal annealing during ambient pressure chemical vapor deposition, followed by their top-down exfoliation. Using multiple techniques, we confirm that monoclinic Cu2S is primarily formed at higher temperatures or greater reaction times and using a reducing atmosphere. We measured the average thickness to be approximately 4 nm for the exfoliated flakes with relatively large lateral sizes of up to 10 μm. We tested the three phases of bulk copper sulfides and their exfoliated forms as photocatalysts for dye degradation …

Natural killer (NK)-cell-based immunotherapy is emerging as an attractive approach for cancer treatment. However, to facilitate and expedite clinical implementation, important questions must be answered regarding the in vivo functionality and trafficking patterns of the transferred cells. We have recently developed a noninvasive cell-tracking technique, based on gold nanoparticles (GNPs) as cell-labeling and contrast agents for whole-body computed tomography (CT) imaging. Herein, we report the implementation of this technique for longitudinal and quantitative tracking of NK cell kinetics, the migration and biodistribution in tumor-bearing mice. NK cells were successfully labeled with GNPs, without impairing their biological function, as assessed both in vitro, by cytokine release and cytotoxicity assays, and in vivo, using a xenograft model of human tumors. Using CT, we longitudinally tracked the migration of …

Electro-oxidation of urea offers tremendous opportunity for the economical hydrogen production option owing to its lower thermodynamic potential barriers. Slower reaction rate and multiple gas desorption steps hinder the implementation of urea-based fuel cells, and thus understanding the urea oxidation process is key for the commercialization of this technology. In this report, we systematically examined the electrocatalytic urea oxidation activity of nickel-based model catalysts such as Ni12P5 and Ni(OH)2 in an alkaline medium at a fixed urea concentration of 0.33 M using electrochemical impedance spectroscopy (EIS). Ni12P5 and Ni(OH)2 require potentials of 0.51 and 0.54 V vs Hg/HgO, respectively, to achieve a current density of 10 mA cm–2. The origin of the catalytic activity difference of the urea oxidation reaction (UOR) between these two Ni catalysts is briefly analyzed using nondestructive in situ EIS. We …

Materials with strongly correlated electrons often exhibit interesting physical properties. An example of these materials is the layered oxide perovskite Sr 2 RuO 4, which has been intensively investigated due to its unusual properties. Whilst the debate on the symmetry of the superconducting state in Sr 2 RuO 4 is still ongoing, a deeper understanding of the Sr 2 RuO 4 normal state appears crucial as this is the background in which electron pairing occurs. Here, by using low-energy muon spin spectroscopy we discover the existence of surface magnetism in Sr 2 RuO 4 in its normal state. We detect static weak dipolar fields yet manifesting at an onset temperature higher than 50 K. We ascribe this unconventional magnetism to orbital loop currents forming at the reconstructed Sr 2 RuO 4 surface. Our observations set a reference for the discovery of the same magnetic phase in other materials and unveil an electronic …

To mitigate the associated challenges of instability and capacity improvement in Na3V2(PO4)2F3 (NVPF), rationally designed uniformly distributed hollow spherical NVPF and coating the surface of NVPF with ultrathin (≈2 nm) amorphous TiO2 by atomic layer deposition is demonstrated. The coating facilitates higher mobility of the ion through the cathode electrolyte interphase (CEI) and enables higher capacity during cycling. The TiO2@NVPF exhibit discharge capacity of >120 mAhg−1, even at 1C rates, and show lower irreversible capacity in the first cycle. Further, nearly 100% capacity retention after rate performance in high current densities and 99.9% coulombic efficiency after prolonged cycling in high current density is reported. The improved performance in TiO2@NVPF is ascribed to the passivation behavior of TiO2 coating which protects the surface of NVPF from volume expansion, significantly less …

In their recent publication, Khatri et al.[1] describe an immunoglobulin germline gene database inferred from shortread genomic sequence data derived from five superpopulations. The development of methods for the compilation of more complete and accurate germline gene databases would be an important achievement, but we do not believe that this has been achieved. Existing databases are clearly incomplete. Germline sequences differ substantially between subjects, and alleles found in some populations may be absent in others. Existing databases are likely biased towards alleles found in European populations and may lack many sequences found in understudied populations [2]. Improved, properly designed and curated germline gene databases are therefore needed for analysis of antibody repertoires.Extensive efforts are under way to better document germline genes, and the study by Khatri et al …

Nanoplasmonic biosensors incorporating noble metal nanocavity arrays are widely used for the detection of various biomarkers. Gold nanorods (GNRs) have unique properties that can enhance spectroscopic detection capabilities of such nanocavity-based biosensors. However, the contribution of the physical properties of multiple GNRs to resonance enhancement of gold nanocavity arrays requires further characterization and elucidation. In this work, we study how GNR aspect ratio (AR) and surface area (SA) modify the plasmonic resonance spectrum of a gold triangular nanocavity array by both simulations and experiments. The finite integration technique (FIT) simulated the extinction spectrum of the gold nanocavity array with 300 nm periodicity onto which the GNRs of different ARs and SAs are placed. Simulations showed that matching of the GNRs longitudinal peak, which is affected by AR, to the nanocavity …

The visibility of nonlinear SU (1, 1) interference directly reflects the nonclassical properties of entangled bi-photons and squeezed light with practically unlimited bandwidth, high efficiency and ultra-high photon flux, orders of magnitude beyond the abilities of standard photo-detectors. We study experimentally the dependence of the SU (1, 1) visibility on the phase matching conditions and beam parameters in a free-space configuration, and show that maximal SU (1, 1) visibility requires extreme collinear conditions, which deviate from the conditions for maximal nonlinear conversion. We demonstrate near-ideal visibility of∼ 95%(limited only by internal loss) in an ultra-broadband SU (1, 1), interferometer with over 120 THz of squeezed light bandwidth. Utilizing this analysis we demonstrate efficient detection of the spectral phase of single-cycle bi-photons and precise compensation of the dispersion over a full octave …

Among many riddles posed by halide perovskites, the surprising apparent near-absence of harmful defects stands out. This is commonly explained by invoking defect tolerance (DT), but the term is used loosely, sometimes interchangeably with self-healing (SH). Also, the relation between underlying physical and chemical mechanisms and device behavior is often murky. Here, we offer our views as to what DT and SH constitute, the evidence for and against them, and what research challenges remain. In the (relatively) early days of the rebirth of halide perovskites, we wrote (with colleagues) a review, 1 originally titled “Hybrid organic− inorganic perovskites: III-V’s on the cheap”. To conform with journal policy, after final acceptance we changed it to the more pedestrian “Hybrid organic− inorganic perovskites: low-cost semiconductors with intriguing charge-transport properties”. Looking at the field today, we realize …

Leishmaniasis is among the five parasitic diseases that still require the development of new drugs. Ultrasmall cerium (Ce3/4+) cation-doped maghemite (γ-Fe2O3) nanoparticles (NPs) were tested as a potential drug to treat visceral leishmaniasis, a disease affecting millions of people worldwide. The NPs were engineered for binding a polycationic branched polyethylenimine (PEI) polymer, thereby rupturing the single lysosome of these parasites and enabling entry of the anti-Leishmania drug, pentamidine. Exploiting the known lanthanide cation/complex-based coordinative chemical reactivity enabled the binding of both active agents onto the surface of the NPs. To optimize the fabrication of the cytotoxic NPs, optimization via a DoE (Design of Experiments) process was used to identify the optimal NP with toxicity against the two stages of the parasite, promastigotes, which propagate in the insect, and amastigotes …

We investigated the nature of graphene surface doping by zwitterionic polymers and the implications of weak in-plane and strong through-plane screening using a novel sample geometry that allows direct access to either the graphene or the polymer side of a graphene/polymer interface. Using both Kelvin probe and electrostatic force microscopies, we observed a significant upshift in the Fermi level in graphene of ∼260 meV that was dominated by a change in polarizability rather than pure charge transfer with the organic overlayer. This physical picture is supported by density functional theory (DFT) calculations, which describe a redistribution of charge in graphene in response to the dipoles of the adsorbed zwitterionic moieties, analogous to a local DC Stark effect. Strong metallic-like screening of the adsorbed dipoles was observed by employing an inverted geometry, an effect identified by DFT to arise from a …

Laser‐induced forward transfer (LIFT) is an additive manufacturing technique where short laser pulses are focused through a transparent substrate onto a thin, uniform, metal layer jetting micrometer‐scale droplets yielding high‐resolution 3D metal structures. Herein, LIFT printing from multilayered metal donors, and from compositional metal mixtures, is explored and presented. A comprehensive study of this sort has been lacking so far. LIFT printing from Cu–Ag structured donors is thoroughly studied. X‐ray diffraction (XRD) analysis reveals the formation of a metastable Cu–Ag phase reflecting the high cooling rate of the metal droplets. Tuning properties of the printed metal structures is made possible by controlling the pulse width and the donor layers’ properties. Longer pulses (10 ns) jetting from cosputtered donors yield better homogeneity than shorter pulses (1 ns) from donors made of distinct sputtered …

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not …

Laser‐induced forward transfer (LIFT) is an additive manufacturing technique where short laser pulses are focused through a transparent substrate onto a thin, uniform, metal layer jetting micrometer‐scale droplets yielding high‐resolution 3D metal structures. Herein, LIFT printing from multilayered metal donors, and from compositional metal mixtures, is explored and presented. A comprehensive study of this sort has been lacking so far. LIFT printing from Cu–Ag structured donors is thoroughly studied. X‐ray diffraction (XRD) analysis reveals the formation of a metastable Cu–Ag phase reflecting the high cooling rate of the metal droplets. Tuning properties of the printed metal structures is made possible by controlling the pulse width and the donor layers’ properties. Longer pulses (10 ns) jetting from cosputtered donors yield better homogeneity than shorter pulses (1 ns) from donors made of distinct sputtered …

Base editors are dedicated engineered deaminases that enable directed conversion of specific bases in the genome or transcriptome in a precise and efficient manner, and hold promise for correcting pathogenic mutations. A major concern limiting application of this powerful approach is the issue of off-target edits. Several recent studies have shown substantial off-target RNA activity induced by base editors and demonstrated that off-target mutations may be suppressed by improved deaminases versions or optimized guide RNAs. Here we describe a new class of off-target events that are invisible to the established methods for detection of genomic variations, and were thus far overlooked. We show that much of the off-target activity of the deaminases is nonspecific, seemingly stochastic, affecting a large number of sites throughout the genome or the transcriptome and accounting for the majority of off-target activity …

The oxygen reduction reaction (ORR) is a key process in anion exchange membrane fuel cells. The alkaline conditions should allow silver‐based cost‐efficient catalysts to replace platinum group metal materials. However, Ag electrochemical stability or lack of stability in alkaline medium is still to be demonstrated. Herein, Ag catalyst nanoparticles (NPs) are characterized by identical location transmission electron microscopy and X‐ray photoelectron spectroscopy after electrochemical cycling, revealing the losses of activity and surface. Herein, a facile method for enhancing the chemical stability of Ag catalysts in an alkaline environment by depositing a protective polydopamine (PDA) coating is reported. It is enhanced via crosslinking with polyethyleneimine (PEI), on the surface of Ag NPs. The enhanced electrochemical stability of Ag PDA–PEI nanocatalyst via the analysis of ORR polarization curves during …

The visibility of nonlinear SU(1,1) interference directly reflects the nonclassical properties of entangled bi-photons and squeezed light with practically unlimited bandwidth, high efficiency and ultra-high photon flux, orders of magnitude beyond the abilities of standard photo-detectors. We study experimentally the dependence of the SU(1,1) visibility on the phase matching conditions and beam parameters in a free-space configuration, and show that maximal SU(1,1) visibility requires extreme collinear conditions, which deviate from the conditions for maximal nonlinear conversion. We demonstrate near-ideal visibility of ~95% (limited only by internal loss) in an ultra-broadband SU(1,1), interferometer with over 120THz of squeezed light bandwidth. Utilizing this analysis we demonstrate efficient detection of the spectral phase of single-cycle bi-photons and precise compensation of the dispersion over a full octave of …

Vehicle detection plays a critical role in autonomous driving, where two central sensing modalities are lidar and radar. Although many deep neural network (DNN)-based methods have been proposed to solve this task, a systematic and methodological examination on the influence of the data on those methods is still missing. In this work, we examine the effects of resolution on the performance of vehicle detection for both lidar and radar sensors. We propose subsampling methods that can improve the performance and efficiency of DNN-based solutions and offer an alternative approach to traditional sensor-design trade-offs.

Solid electrolytes based on polyethylene oxide (PEO) have been studied for decades, owing to their facile and low-cost processing, good electrochemical stability, and excellent complexation with alkali metal salts. Complexes of PEO with appropriate sodium salts are well known for ionic conduction. Here, pristine NaPF6:P(EO)16 and a composite solid electrolyte containing TiO2 nanowires were investigated as candidates for rechargeable solid-state sodium batteries. Comprehensive electrochemical characterizations were carried out, including ionic conductivity, transference number, and structural stability. At elevated temperatures, the specific capacity of an all-solid-state Na3Ti2(PO4)3 (Na/NTP) sodium battery was 110 mAh g-1, higher than room-temperature cells with liquid electrolyte solutions. We attribute this behavior to increased con-ductivity of the polymer electrolyte, induced by the ceramic nanofiller, combined with enhanced electronic conductivity of the NTP cathode.