BINA

Thermoelastic stimulation of surface acoustic waves in standard silicon photonic circuits is enhanced through the absorption of pump light in surface plasmon resonant unit cells. Transmission losses are reduced by 20 dB.

In recent years, steady progress has been made in synthesizing and characterizing engineered nanoparticles, resulting in several approved drugs and multiple promising candidates in clinical trials. Regulatory agencies such as the Food and Drug Administration and the European Medicines Agency released important guidance documents facilitating nanoparticle-based drug product development, particularly in the context of liposomes and lipid-based carriers. Even with the progress achieved, it is clear that many barriers must still be overcome to accelerate translation into the clinic. At the recent conference workshop “Mechanisms and Barriers in Nanomedicine” in May 2023 in Colorado, U.S.A., leading experts discussed the formulation, physiological, immunological, regulatory, clinical, and educational barriers. This position paper invites open, unrestricted, nonproprietary discussion among senior faculty, young …

Carbonaceous materials are the most common catalyst supports in proton exchange membrane fuel cell (PEMFCs), yet their corrosion is one of the limiting factors in achieving high durability. Herein, we doped carbon supports with boron (B) to increase the corrosion-resistance of the support. Two types of B-doped carbons were synthesized and studied as platinum support materials. They varied in their morphologies, surface areas, and the types of boron species. The durability of Pt/B-doped carbon catalysts was investigated using the US-DOE catalysts’ supports accelerated stress test (AST) and a mass-spectrometer connected to the fuel cell effluent stream to quantify the mass of corroded carbon support in operando. The addition of boron to the carbon increased the stability of Pt catalysts in long-term usage of PEMFC. After 4,000 AST cycles, more than 50% of initial current density was preserved for the boron …

Chiral induction of chiral crystals attracts significant attention due to its implications for developing chiral materials and understanding mechanisms of symmetry breaking enantioselective crystallization of naturally chiral inorganic crystals and their potential use in chiral discrimination, which are, however, largely unexplored. Here, we investigate the chiral induction during the crystallization of naturally chiral Ag2CO3 crystals using arginine amino acid as the chiral inducer. The chiral nature of Ag2CO3 was evaluated using various techniques. Chiral crystals exhibited chiral selective binding toward different amino acid enantiomers. The significant selectivity in adsorption was confirmed by circular dichroism, high-performance liquid chromatography, and isothermal titration calorimetry. Understanding chiral induction in crystal growth may open avenues for the controlled assembly of chiral materials and the development …

We demonstrate resolution enhancement of a standard hard x-ray imaging system from 500 μm to approximately 20 μm by extending the concept of ghost imaging to multipixel ghost imaging, enabling mega-pixel scale imaging in a short timeframe.

We demonstrate the pioneering use of a quantum interferometer with x-rays, highlighting its effectiveness in precisely measuring the phase accumulated in opaque media. Our work uncovers novel opportunities for measuring sub-Angstrom optical-path differences.

Computational spectrometry is an emerging field that uses photodetection in conjunction with numerical algorithms for spectroscopic measurements. Compact single photodetectors made from layered materials are particularly attractive since they eliminate the need for bulky mechanical and optical components used in traditional spectrometers and can easily be engineered as heterostructures to optimize device performance. However, such photodetectors are typically nonlinear devices, which adds complexity to extracting optical spectra from their response. Here, we train an artificial neural network to recover the full nonlinear spectral photoresponse of a single GeSe-InSe p-n heterojunction device. The device has a spectral range of 400 to 1100 nm, a small footprint of ~25 × 25 square micrometers, and a mean reconstruction error of 2 × 10−4 for the power spectrum at 0.35 nanometers. Using our device, we …

A synergistic stabilization effect in a Nb-doped P2-type single crystal cobalt-free layered oxide cathode material, offering remarkable cycling stability and high-power performance for Na-ion batteries have unveiled in this study. The introduction of Nb in the transition metal layer not only reduces the electronic band gap but also enhances electronic conductivity and mitigates ionic diffusion energy barriers. The induction of a robust Nb-O bond expedites electron and Na+ transfer, contributing to the stabilization of the host structure is further confirmed through the density functional theory calculations, including electron localization function (ELF) and crystal orbital Hamiltonian population (COHP). To the best of our knowledge, this study is the first to demonstrate a homogeneous distribution of niobium throughout the single crystal, specifically doped at the nickel site within the bulk, without inducing atomic-scale surface …

Electrocatalysts play a critical role in energy technologies, but the development of active, efficient, and durable catalysts is impeded by the lack of methodologies to deconvolute the complex interplay between various aspects influencing the activity of the catalysts, e.g., the number of active sites, turnover frequency, and the reaction pathways. Fourier-transformed alternating current voltammetry (FTacV) is an emerging tool for the analysis of electroactive species and has been successfully applied to a variety of reactions such as the oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction, hydrogen evolution reaction, and hydrogen oxidation reaction. The harmonics generated from FTacV measurements neatly detect underlaying processes not visible by other, more commonly employed techniques for analysis of electrocatalysts, such as the rotating disc electrode and dc voltammetry …

The COVID-19 pandemic highlighted the necessity of fast, sensitive, and efficient methods to test large populations for respiratory viruses. The “gold standard” molecular assays for detecting respiratory viruses, such as quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR), rely on invasive swab samples and require time-consuming and labor-intensive extraction processes. Moreover, the turnaround time for RT-qPCR-based assays is too lengthy for rapid screening. Extraction-free saliva-based methods provide a non-invasive sampling process with a fast turnaround time and are suitable for high-throughput applications. However, when used with a standard RT-qPCR system, the absence of extraction significantly reduces the assays’ sensitivity. Here, using a novel optical modulation biosensing (OMB) platform, we developed a rapid and highly sensitive extraction-free saliva …

In the current work, we analyzed the origin of difference in stabilities among the germacrene A and hedycaryol-derived carbocations. This study focused on twelve hydrocarbons derived from germacrene A and twelve from hedycaryol, which can be divided into three groups: four molecules containing 6-6 bicyclic rings, four 5-7 bicyclic compounds with the carbocation being on the seven-membered ring and the remaining four 5-7 bicyclic compounds with the carbocation on the five-membered ring. The variations in energy within the groups of carbocations (ie, 6-6 and two kinds of 5-7 bicyclic carbocations) can be ascribed to intramolecular repulsion interactions, as seen from non-covalent interactions plots. Despite the structural similarities between germacrene A and hedycaryol cations, they possess a somewhat different stability trend. These differences are attributed to C+··· OH intramolecular interactions present in some hedycaryol cations, which are absent in the carbocations derived from germecrene A.

Materials that transition between metal and insulator, the two opposing states that distinguish all solids, are fascinating because they underlie many mysteries in the physics of the solid state. In 1T-TaS, the metal-insulator transition is linked to a series of metastable states of a chiral charge density wave whose basic nature is still an open question. In this work, we show that pulses of current through these materials create current-carrying boundary channels that distinguish the metallic and insulating states. We demonstrate electrical control of these channels' properties, suggesting their formation could be due to the complex interplay of the formation of domain walls and the viscous flow of electrons. Our findings show that physical boundaries play a key role in the properties of the metastable states of the metal-insulator transition, highlighting new possibilities for in-situ electrical design and active manipulation of electrical components.

The COVID-19 pandemic highlighted the necessity of fast, sensitive, and efficient methods to test large populations for respiratory viruses. The “gold standard” molecular assays for detecting respiratory viruses, such as quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR), rely on invasive swab samples and require time-consuming and labor-intensive extraction processes. Moreover, the turnaround time for RT-qPCR-based assays is too lengthy for rapid screening. Extraction-free saliva-based methods provide a non-invasive sampling process with a fast turnaround time and are suitable for high-throughput applications. However, when used with a standard RT-qPCR system, the absence of extraction significantly reduces the assays’ sensitivity. Here, using a novel optical modulation biosensing (OMB) platform, we developed a rapid and highly sensitive extraction-free saliva …

The Kirkwood-Dirac quasiprobability distribution emerges from the quantum correlation function of two observables measured at distinct times and is therefore relevant for fundamental physics and quantum technologies. These quasiprobabilities follow all but one of Kolmogorov axioms for joint probability distributions: they can take non-positive values. Their experimental reconstruction becomes challenging when expectation values of incompatible observables are involved. Previous strategies aimed to reconstruct them using weak measurements or combining strong measurements. Here, we use a more direct approach, an interferometric scheme aided by an auxiliary system, to reconstruct the Kirkwood-Dirac quasiprobability distribution. We experimentally demonstrate the interferometric scheme in an electron-nuclear spin system associated with a nitrogen-vacancy center in diamond. By measuring the characteristic function, we reconstruct the quasiprobability distribution of the work and analyze the behavior of the first and second moments of work. Our results clarify the physical meaning of the work quasiprobability distribution in the context of quantum thermodynamics. Finally, having measured the real and imaginary parts of the Kirkwood-Dirac quasiprobability of work, we are also able to study the uncertainty of measuring the Hamiltonian of the system at two times, via the Robertson-Schr{\"o}dinger uncertainty relation, for different initial states.

Electrocatalysts play a critical role in energy technologies, but the development of active, efficient, and durable catalysts is impeded by the lack of methodologies to deconvolute the complex interplay between various aspects influencing the activity of the catalysts, e.g., the number of active sites, turnover frequency, and the reaction pathways. Fourier-transformed alternating current voltammetry (FTacV) is an emerging tool for the analysis of electroactive species and has been successfully applied to a variety of reactions such as the oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction, hydrogen evolution reaction, and hydrogen oxidation reaction. The harmonics generated from FTacV measurements neatly detect underlaying processes not visible by other, more commonly employed techniques for analysis of electrocatalysts, such as the rotating disc electrode and dc voltammetry …

Leishmania is the causative agent of cutaneous and visceral diseases affecting millions of individuals worldwide. Pseudouridine (Ψ), the most abundant modification on rRNA, changes during the parasite life cycle. Alterations in the level of a specific Ψ in helix 69 (H69) affected ribosome function. To decipher the molecular mechanism of this phenotype, we determine the structure of ribosomes lacking the single Ψ and its parental strain at ∼2.4–3 Å resolution using cryo-EM. Our findings demonstrate the significance of a single Ψ on H69 to its structure and the importance for its interactions with helix 44 and specific tRNAs. Our study suggests that rRNA modification affects translation of mRNAs carrying codon bias due to selective accommodation of tRNAs by the ribosome. Based on the high-resolution structures, we propose a mechanism explaining how the ribosome selects specific tRNAs.

Carbonaceous materials are the most common catalyst supports in proton exchange membrane fuel cell (PEMFCs), yet their corrosion is one of the limiting factors in achieving high durability. Herein, we doped carbon supports with boron (B) to increase the corrosion-resistance of the support. Two types of B-doped carbons were synthesized and studied as platinum support materials. They varied in their morphologies, surface areas, and the types of boron species. The durability of Pt/B-doped carbon catalysts was investigated using the US-DOE catalysts’ supports accelerated stress test (AST) and a mass-spectrometer connected to the fuel cell effluent stream to quantify the mass of corroded carbon support in operando. The addition of boron to the carbon increased the stability of Pt catalysts in long-term usage of PEMFC. After 4,000 AST cycles, more than 50% of initial current density was preserved for the boron …

We present free-electron imaging of sub-cycle spatio-temporal dynamics of 2D polariton wavepackets, demonstrating the first simultaneous time-, space-, and phase-resolved measurement of such phenomena, and resolving their novel features like vortex-anti-vortex singularities for record-low intensities.

Terpene synthases (TPSs) catalyze the first step in the formation of terpenoids, which comprise the largest class of natural products in nature. TPSs employ a family of universal natural substrates, composed of isoprenoid units bound to a diphosphate moiety. The intricate structures generated by TPSs are the result of substrate binding and folding in the active site, enzyme‐controlled carbocation reaction cascades, and final reaction quenching. A key unaddressed question in class I TPSs is the asymmetric nature of the diphosphate‐(Mg2+)3 cluster, which forms a critical part of the active site. In this asymmetric ion cluster, two diphosphate oxygen atoms protrude into the active site pocket. The substrate hydrocarbon tail, which is eventually molded into terpenes, can bind to either of these oxygen atoms, yet to which is unknown. Herein, we employ structural, bioinformatics, and EnzyDock docking tools to address this …

Enhanced catalytic activity of oxygen evolution reaction (OER) catalysts is necessary to lower the cost of green hydrogen production. This study focuses on the use of a simple strategy of heat treatment to enhance the catalytic activity of NiFeOOH-based aerogels. The study shows that heat treatment of this aerogel at 150 °C leads to significant improvement in its catalytic activity, as evident in the staircase voltammetry results. To understand how heat treatment improves the catalytic activity, a DFT+U calculation was carried out on heat-treated and non-heat-treated catalysts. The calculation shows that the overpotential for OER decreases with heat treatment, which is related to the relative stability of the intermediates in heat-treated and non-heat-treated catalysts. Also, it has been found that heat treatment decreases work function, which might improve charge transfer and, thus, catalytic activity. Our calculations are in …