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Jan 2021 • Materials Today

Periodical concentration of surface plasmon polaritons by wave interference in metallic film with nanocavity array

Xiaotian Xue, Yihang Fan, Elad Segal, Weipeng Wang, Fei Yang, Yanfeng Wang, Fengtong Zhao, Wangyang Fu, Yunhan Ling, Adi Salomon, Zhengjun Zhang

Metallic thin films with nanocavity arrays provide ideal platforms for plasmonics, non-linear optics, surface chemistry and corresponding applications. A general understanding of electromagnetic (EM) field distributions is needed for further creation, manipulation and designation of near-field enhancements. Herein, we study the distribution of plasmonic hot spots over Ag thin films with triangular nanocavities in hexagonal arrays with a variable of lattice parameters. We propose that the concentration and interference of surface plasmon polaritons (SPP) dominates the distribution of plasmonic hot spots. The localized surface plasmonic resonance (LSPR) at nanocavities excites SPPs to propagate on the thin film, whose concentration and interference lead to an extremely strong near-field enhancement at the surface of the thin film, the location of which can also be termed as plasmonic hot spot. For this model, the …

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Jan 2021 • Applied Sciences

Protective Measurement—A New Quantum Measurement Paradigm: Detailed Description of the First Realization

Enrico Rebufello, Fabrizio Piacentini, Alessio Avella, Rudi Lussana, Federica Villa, Alberto Tosi, Marco Gramegna, Giorgio Brida, Eliahu Cohen, Lev Vaidman, Ivo Pietro Degiovanni, Marco Genovese

We present a detailed description of the experiment realizing for the first time a protective measurement, a novel measurement protocol which combines weak interactions with a “protection mechanism” preserving the measured state coherence during the whole measurement process. Furthermore, protective measurement allows finding the expectation value of an observable, ie, an inherently statistical quantity, by measuring a single particle, without the need for any statistics. This peculiar property, in sharp contrast to the framework of traditional (projective) quantum measurement, might constitute a groundbreaking advance for several quantum technology related fields. View Full-Text

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Jan 2021 • Nature Communications

Observation of anti-parity-time-symmetry, phase transitions and exceptional points in an optical fibre

Arik Bergman, Robert Duggan, Kavita Sharma, Moshe Tur, Avi Zadok, Andrea Alù

The exotic physics emerging in non-Hermitian systems with balanced distributions of gain and loss has recently drawn a great deal of attention. These systems exhibit phase transitions and exceptional point singularities in their spectra, at which eigen-values and eigen-modes coalesce and the overall dimensionality is reduced. So far, these principles have been implemented at the expense of precise fabrication and tuning requirements, involving tailored nano-structured devices with controlled optical gain and loss. In this work, anti-parity-time symmetric phase transitions and exceptional point singularities are demonstrated in a single strand of single-mode telecommunication fibre, using a setup consisting of off-the-shelf components. Two propagating signals are amplified and coupled through stimulated Brillouin scattering, enabling exquisite control over the interaction-governing non-Hermitian parameters …

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Jan 2021 • Nano Energy

MXene conductive binder for improving performance of sodium-ion anodes in water-in-salt electrolyte

Fyodor Malchik, Netanel Shpigel, Mikhael D Levi, Tirupathi Rao Penki, Bar Gavriel, Gil Bergman, Meital Turgeman, Doron Aurbach, Yury Gogotsi

While many studies have been devoted to the development of new active materials for Na-ion aqueous batteries, much less attention has been given to the binders and other passive components, which largely determine the battery performance. This study demonstrates a beneficial use of MXene as a highly efficient binder for Na-ion anodes operating in aqueous electrolyte solutions. The high conductivity of 2D titanium carbide (Ti3C2Tx; T = terminal groups, mostly –OH, 0 < x < 2) denoted as MXene and the strong attractive interactions between its sheets and active material particles enable their effective encapsulation providing electronically conductive paths, fast ion transfer, and capacitive contribution to the stored charge. Using highly concentrated NaClO4 as an electrolyte solution providing a stable potential operation window, successful integration of NaTi2(PO3)4 (NTP) particles with MXene as a binding …

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Jan 2021 • bioRxiv

The Conformational Plasticity of the Selectivity Filter Methionines Controls the In-Cell Cu (I) Uptake through the CTR1 transporter

Pavel Janoš, Jana Aupič, Sharon Ruthstein, Alessandra Magistrato

Copper is a trace element vital to many cellular functions. Yet its abnormal levels are toxic to cells, provoking a variety of severe diseases. The high affinity Copper Transporter 1 (CTR1), being the main in-cell copper (Cu(I)) entry route, tightly regulates its cellular uptake via a still elusive mechanism. Here, all-atoms simulations unlock the molecular terms of Cu(I) transport in eukaryotes disclosing that the two Methionine triads, forming the selectivity filter, play an unprecedented dual role both enabling selective Cu(I) transport and regulating its uptake-rate thanks to an intimate coupling between the conformational plasticity of their bulky side chains and the number of bound Cu(I) ions. Namely, the Met residues act as a gate reducing the Cu(I) import-rate when two ions simultaneously bind to CTR1. This may represent an elegant autoregulatory mechanism through which CTR1 protects the cells from excessively high, and hence toxic, in-cell Cu(I) levels. Overall, these outcomes resolve fundamental questions in CTR1 biology and open new windows of opportunity to tackle diseases associated with an imbalanced copper uptake.

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Jan 2021 • Physical Review Letters

Faceting and flattening of emulsion droplets: A mechanical model

Ireth García-Aguilar, Piermarco Fonda, Eli Sloutskin, Luca Giomi

When cooled down, emulsion droplets stabilized by a frozen interface of alkane molecules and surfactants have been observed to undergo a spectacular sequence of morphological transformations: from spheres to faceted liquid icosahedra, down to flattened liquid platelets. While generally ascribed to the interplay between the elasticity of the frozen interface and surface tension, the physical mechanisms underpinning these transitions have remained elusive, despite different theoretical pictures having been proposed in recent years. In this Letter, we introduce a comprehensive mechanical model of morphing emulsion droplets, which quantitatively accounts for various experimental observations, including the size scaling behavior of the faceting transition. Our analysis highlights the role of gravity and the spontaneous curvature of the frozen interface in determining the specific transition pathway.

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Jan 2021 • Nature communications

Alternating quarantine for sustainable epidemic mitigation

Dror Meidan, Nava Schulmann, Reuven Cohen, Simcha Haber, Eyal Yaniv, Ronit Sarid, Baruch Barzel

Absent pharmaceutical interventions, social distancing, lock-downs and mobility restrictions remain our prime response in the face of epidemic outbreaks. To ease their potentially devastating socioeconomic consequences, we propose here an alternating quarantine strategy: at every instance, half of the population remains under lockdown while the other half continues to be active-maintaining a routine of weekly succession between activity and quarantine. This regime minimizes infectious interactions, as it allows only half of the population to interact for just half of the time. As a result it provides a dramatic reduction in transmission, comparable to that achieved by a population-wide lockdown, despite sustaining socioeconomic continuity at~ 50% capacity. The weekly alternations also help address the specific challenge of COVID-19, as their periodicity synchronizes with the natural SARS-CoV-2 disease time-scales …

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Jan 2021 • Sensors

Remote photoacoustic sensing using single speckle analysis by an ultra-fast four quadrant photo-detector

Benjamin Lengenfelder, Martin Hohmann, Moritz Späth, Daniel Scherbaum, Manuel Weiß, Stefan J Rupitsch, Michael Schmidt, Zeev Zalevsky, Florian Klämpfl

The need for tissue contact makes photoacoustic imaging not applicable for special medical applications like wound imaging, endoscopy, or laser surgery. An easy, stable, and contact-free sensing technique might thus help to broaden the applications of the medical imaging modality. In this work, it is demonstrated for the first time that remote photoacoustic sensing by speckle analysis can be performed in the MHz sampling range by tracking a single speckle using a four quadrant photo-detector. A single speckle, which is created by self-interference of surface back-reflection, is temporally analyzed using this photo-detector. Phantoms and skin samples are measured in transmission and reflection mode. The potential for miniaturization for endoscopic application is demonstrated by fiber bundle measurements. In addition, sensing parameters are discussed. Photoacoustic sensing in the MHz sampling range by single speckle analysis with the four quadrant detector is successfully demonstrated. Furthermore, the endoscopic applicability is proven, and the sensing parameters are convenient for photoacoustic sensing. It can be concluded that a single speckle contains all the relevant information for remote photoacoustic signal detection. Single speckle sensing is therefore an easy, robust, contact-free photoacoustic detection technique and holds the potential for economical, ultra-fast photoacoustic sensing. The new detection technique might thus help to broaden the field of photoacoustic imaging applications in the future. View Full-Text

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Jan 2021 • Sensors

Rapid and Sensitive Inhibitor Screening Using Magnetically Modulated Biosensors

Shira Roth, Amos Danielli

Inhibitor screening is an important tool for drug development, especially during the COVID-19 pandemic. The most used in vitro inhibitor screening tool is an enzyme-linked immunosorbent assay (ELISA). However, ELISA-based inhibitor screening is time consuming and has a limited dynamic range. Using fluorescently and magnetically modulated biosensors (MMB), we developed a rapid and sensitive inhibitor screening tool. This study demonstrates its performance by screening small molecules and neutralizing antibodies as potential inhibitors of the interaction between the spike protein 1 (S1) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the angiotensin-converting enzyme 2 (ACE2) receptor. The MMB-based assay is highly sensitive, has minimal non-specific binding, and is much faster than the commonly used ELISA (2 h vs. 7–24 h). We anticipate that our method will lead to a remarkable advance in screening for new drug candidates.

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Jan 2021 • Science

Expansion sequencing: Spatially precise in situ transcriptomics in intact biological systems

Shahar Alon, Daniel R Goodwin, Anubhav Sinha, Asmamaw T Wassie, Fei Chen, Evan R Daugharthy, Yosuke Bando, Atsushi Kajita, Andrew G Xue, Karl Marrett, Robert Prior, Yi Cui, Andrew C Payne, Chun-Chen Yao, Ho-Jun Suk, Ru Wang, Chih-Chieh Jay Yu, Paul Tillberg, Paul Reginato, Nikita Pak, Songlei Liu, Sukanya Punthambaker, Eswar PR Iyer, Richie E Kohman, Jeremy A Miller, Ed S Lein, Ana Lako, Nicole Cullen, Scott Rodig, Karla Helvie, Daniel L Abravanel, Nikhil Wagle, Bruce E Johnson, Johanna Klughammer, Michal Slyper, Julia Waldman, Judit Jané-Valbuena, Orit Rozenblatt-Rosen, Aviv Regev, IMAXT Consortium19, George M Church, Adam H Marblestone, Edward S Boyden

INTRODUCTION Cells and tissues are made up of diverse molecular building blocks, organized with nanoscale precision over extended length scales. Newly developed techniques that enable highly multiplexed, nanoscale, and subcellular analysis of such systems are required. Although much progress has been made on methods for multiplexed RNA imaging, these methods have been limited in their spatial precision, especially in the context of three-dimensional systems such as tissues. Because of this limitation, interrogation of tissues has been performed with either high spatial resolution or high molecular multiplexing capacity, but not both.RATIONALE We reasoned that physically expanding specimens by adapting expansion microscopy could help support spatially precise in situ sequencing. The physical expansion of specimens provides two benefits: First, it enables ordinary microscopes to achieve …

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Jan 2021 • Advanced Materials

Mutually Reinforced Polymer–Graphene Bilayer Membranes for Energy‐Efficient Acoustic Transduction

Assad U Khan, Gabriel Zeltzer, Gavriel Speyer, Zacary L Croft, Yichen Guo, Yehiel Nagar, Vlada Artel, Adi Levi, Chen Stern, Doron Naveh, Guoliang Liu

Graphene holds promise for thin, ultralightweight, and high‐performance nanoelectromechanical transducers. However, graphene‐only devices are limited in size due to fatigue and fracture of suspended graphene membranes. Here, a lightweight, flexible, transparent, and conductive bilayer composite of polyetherimide and single‐layer graphene is prepared and suspended on the centimeter scale with an unprecedentedly high aspect ratio of 105. The coupling of the two components leads to mutual reinforcement and creates an ultrastrong membrane that supports 30 000 times its own weight. Upon electromechanical actuation, the membrane pushes a massive amount of air and generates high‐quality acoustic sound. The energy efficiency is ≈10–100 times better than state‐of‐the‐art electrodynamic speakers. The bilayer membrane's combined properties of electrical conductivity, mechanical strength, optical …

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Jan 2021 • Nanomaterials

Solvent-free mechanochemical synthesis of ZnO nanoparticles by high-energy ball milling of ε-Zn (OH) 2 crystals

Gil Otis, Michal Ejgenberg, Yitzhak Mastai

A detailed investigation is presented for the solvent-free mechanochemical synthesis of zinc oxide nanoparticles from ε-Zn (OH) 2 crystals by high-energy ball milling. Only a few works have ever explored the dry synthetic route from ε-Zn (OH) 2 to ZnO. The milling process of ε-Zn (OH) 2 was done in ambient conditions with a 1: 100 powder/ball mass ratio, and it produced uniform ZnO nanoparticles with sizes of 10–30 nm, based on the milling duration. The process was carefully monitored and the effect of the milling duration on the powder composition, nanoparticle size and strain, optical properties, aggregate size, and material activity was examined using XRD, TEM, DLS, UV-Vis, and FTIR. The mechanism for the transformation of ε-Zn (OH) 2 to ZnO was studied by TGA and XPS analysis. The study gave proof for a reaction mechanism starting with a phase transition of crystalline ε-Zn (OH) 2 to amorphous Zn (OH) 2, followed by decomposition to ZnO and water. To the best of our knowledge, this mechanochemical approach for synthesizing ZnO from ε-Zn (OH) 2 is completely novel. ε-Zn (OH) 2 crystals are very easy to obtain, and the milling process is done in ambient conditions; therefore, this work provides a simple, cheap, and solvent-free way to produce ZnO nanoparticles in dry conditions. We believe that this study could help to shed some light on the solvent-free transition from ε-Zn (OH) 2 to ZnO and that it could offer a new synthetic route for synthesizing ZnO nanoparticles. View Full-Text

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Jan 2021 • bioRxiv

Sexual deprivation modulates social interaction and reproductive physiology

Liora Omesi, Mali Levi, Assa Bentzur, Yong-Kyu Kim, Shir Ben-Shaanan, Reza Azanchi, Ulrike Heberlein, Galit Shohat-Ophir

2021 • Frontiers in Energy Research

Na0. 44MnO2/Polyimide Aqueous Na-ion Batteries for Large Energy Storage Applications

Satyanarayana Maddukuri, Amey Nimkar, Munseok S Chae, Tirupathi Rao Penki, Shalom Luski, Doron Aurbach

Aqueous salt batteries with high concentration of salt or water in salt aqueous systems have received considerable attention with focus on improving working voltage range and energy density. Here, the effect of concentration on electrochemical performance and stability of tunnel-type Na0.44MnO2 (NMO) cathode and organic polyimide (PI) derivative as an anode was studied. High capacity retention and 100% coulombic efficiency are shown for NMO/PI full cell in saturated NaClO4 electrolyte. A high stable capacity of 115 mAh/g was achieved for the PI anode material, and the full cell showed stable capacity of 41 mAh/g at 2C rate for 430 cycles (calculated for the weight of NMO cathode). Even at fast 5C rate, a discharge capacity of 33 mAh/g was maintained for 2,400 prolonged cycles with nearly 100% efficiency. The full cell device can achieve an average voltage of 1 V with energy density of 24 Wh/kg. This study highlights concentrated sodium perchlorate as a promising electrolyte solution for stabilization of electrodes and enhancement of electrochemical performance in aqueous media.

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2021 • RNA Editing, 213-227, 2021

Detection of A-to-I Hyper-edited RNA Sequences

Roni Cohen-Fultheim, Erez Y Levanon

Following A-to-I editing of double-stranded RNA (dsRNA) molecules, sequencing reactions interpret the edited inosine (I) as guanosine (G). For this reason, current methods to detect A-to-I editing sites work to align RNA sequences to their reference DNA sequence in order to reveal A-to-G mismatches. However, areas with heavily edited reads produce dense clusters of A-to-G mismatches that hinder alignment, and complicate correct identification of the sites. The presented approach employs prudent alignment and examination of excessive mismatch events, enabling high-accuracy detection of hyper-edited reads and sites.

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2021 • Catalysis Science & Technology

Operando X-ray absorption spectroscopy of a Pd/γ-NiOOH 2 nm cubes hydrogen oxidation catalyst in an alkaline membrane fuel cell

Maria Alesker, Istvan Bakos, Veronica Davies, Qingying Jia, Luba Burlaka, Valeria Yarmiayev, Anya Muzikansky, Anna Kitayev, Miles Page, Sanjeev Mukerjee, David Zitoun

A fundamental understanding of the hydrogen oxidation reaction (HOR) mechanism requires the synthesis of model catalysts with designed surfaces, and advanced characterization techniques of the active sites. Although HOR are fast under acidic conditions, HOR kinetics are sluggish under alkaline conditions, even on platinum group metals (PGMs). Herein, we propose the use of an effective high-surface-area carbon supported Pd/γ-NiOOH HOR electrocatalyst, made from organometallic precursors. The enhanced activity, provided by nickel oxy-hydroxide (γ-NiOOH) 2 nm nanocubes, was confirmed experimentally in an alkaline exchange membrane fuel cell. Contrary to previous reports, the phase and crystallographic orientation of the γ-NiOOH nanocubes (<2 nm in size) were fully ascribed through high-resolution transmission electron microscopy. Operando X-ray absorption spectroscopy revealed a redox …

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2021 • Materials Horizons

The pursuit of stability in halide perovskites: the monovalent cation and the key for surface and bulk self-healing

DR Ceratti, AV Cohen, R Tenne, Y Rakita, L Snarski, NP Jasti, L Cremonesi, R Cohen, M Weitman, I Rosenhek-Goldian, I Kaplan-Ashiri, T Bendikov, V Kalchenko, M Elbaum, MAC Potenza, L Kronik, G Hodes, D Cahen

We find significant differences between degradation and healing at the surface or in the bulk for each of the different APbBr3 single crystals (A = CH3NH3+, methylammonium (MA); HC(NH2)2+, formamidinium (FA); and cesium, Cs+). Using 1- and 2-photon microscopy and photobleaching we conclude that kinetics dominate the surface and thermodynamics the bulk stability. Fluorescence-lifetime imaging microscopy, as well as results from several other methods, relate the (damaged) state of the halide perovskite (HaP) after photobleaching to its modified optical and electronic properties. The A cation type strongly influences both the kinetics and the thermodynamics of recovery and degradation: FA heals best the bulk material with faster self-healing; Cs+ protects the surface best, being the least volatile of the A cations and possibly through O-passivation; MA passivates defects via methylamine from photo …

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2021 • CRISPR Guide RNA Design, 37-48, 2021

Chemical modification of guide RNAs for improved CRISPR activity in CD34+ human hematopoietic stem and progenitor cells

Jenny Shapiro, Adi Tovin, Ortal Iancu, Daniel Allen, Ayal Hendel

Human CD34+ hematopoietic stem and progenitor cells (HSPCs) have the unique ability to repopulate the entire hematopoietic system and thus are at the center of diverse, therapeutically relevant studies. The recent development of the CRISPR/Cas9 tool made the powerful research technique of genome editing highly accessible. Our previous studies demonstrated that high editing efficiency is reached when the CRISPR/Cas9 is introduced to CD34+ HSPCs as a ribonucleoprotein (RNP) complex with chemically modified guide RNAs (gRNAs). The current protocol details a quick 4-day procedure for ex vivo genome editing in CD34+ HSPCs by RNP complexes that are targeted to a specific locus by either a single gRNA (sgRNA) or a 2-part gRNA. The delivery of RNP complexes is performed by electroporation in the presence of a nonspecific, ssDNA electroporation enhancer, which highly improves editing …

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2021 • Chemical Communications

Combining polarized low-frequency Raman with XRD to identify directional structural motifs in a pyrolysis precursor

Tal Ben Uliel, Eliyahu M Farber, Hagit Aviv, Wowa Stroek, Marilena Farbinteanu, Yaakov R Tischler, David Eisenberg

Long–range structures and dynamics are central to coordination chemistry, yet are hard to identify experimentally. By combining polarized low-frequency Raman spectroscopy with single crystal XRD to study barium nitrilotriacetate, a metal–organic coordination polymer and a useful pyrolysis precursor, we could assign Raman peaks experimentally to layer shear motions and perpendicular hydrogen bond vibrations. These directional long–range interactions further determined the preferred fracture directions during crystallization, establishing an important link between structural motifs in the precursor, and the porosity of the carbon it yields upon pyrolysis.

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2021 • Materials Horizons

Ultra-small natural product based coordination polymer nanodots for acute kidney injury relief

Rui Zhang, Liang Cheng, Ziliang Dong, Linqian Hou, Shaohua Zhang, Zhouqi Meng, Oshra Betzer, Yihua Wang, Rachela Popovtzer, Zhuang Liu

Acute kidney injury (AKI) is frequently associated with reactive oxygen species (ROS) and causes high mortality in clinics annually, and nanotechnology-mediated antioxidative therapy is emerging as a novel strategy for AKI treatment. Herein, four kinds of natural antioxidants are able to coordinate with iron (Fe) ions to form ultra-small coordination polymer nanodots (CPNs) with good water dispersibility and strong ROS scavenging ability. In particular, Fe–curcumin CPNs (Fe–Cur CPNs) are applied for cellular ROS scavenging and rhabdomyolysis-induced AKI relief.

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2021 • Quantum Electronics

Interaction of laser radiation and complexes of gold nanoparticles linked with proteins

Sergei Vladimirovich Zar'kov, Yu A Avetisyan, Aleksandr Nikolaevich Yakunin, Irina Gennad'evna Meerovich, D Fixler, Aleksandr Pavlovich Savitsky, Valerii Viktorovich Tuchin

The results of numerical simulation of the near-field distribution inside and in the vicinity of two types of gold nanoparticles (nanospheres and nanorods) intended for producing complexes of gold nanoparticles linked with proteins and exciting photosensitizers in the wavelength range of 532–770 nm are presented. Quantitative estimates of the field localisation (enhancement) are obtained depending on the type of gold nanoparticles and dimensional factors. The tendency of the red shift of the wavelength at which the maximum local field enhancement is achieved relative to the positions of the maxima of the absorption and scattering cross sections of nanoparticles and complexes is described.

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