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Mar 2020 • Journal of Magnetism and Magnetic Materials

Structural and magnetic investigations on Cu-doped MnV2O6 compound: Experiment and theory

N Khamaru, S De, A Das, Vijay Singh, Dan Thomas Major, P Dasgupta, D Das, S Chatterjee

Effects of Cu-doping on the structural and magnetic properties of spin chain compound MnV2O6 have been investigated through experimental and theoretical techniques. Significant change in magnetic properties with Cu-doping have been observed. Increasing defects and disorders with Cu-doping which often results in a breaking of infinite chains along b-axis into finite segments play pivotal role towards the decrease in the intrachain exchange interaction. Defects, disorders and hence the chain breaking also affects the magnetic susceptibility of the compound and an increasing Curie tail has been observed. In addition, increasing contribution of orbital moment has been observed with doping. Observation of metamagnetism in both pure and doped compounds is the another key feature observed. First-principles electronic structure calculations have been employed to understand the observed increase in the …

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Mar 2020 • Physical Review Research

Surface states and arcless angles in twisted Weyl semimetals

Ganpathy Murthy, Herbert A Fertig, Efrat Shimshoni

Fermi arc states are features of Weyl semimetal (WSM) surfaces which are robust due to the topological character of the bulk band structure. We demonstrate that Fermi arcs may undergo profound restructurings when surfaces of different systems with a well-defined twist angle are tunnel coupled. The twisted WSM interface supports a moiré pattern which may be approximated as a periodic system with a large real-space unit cell. States bound to the interface emerge, with interesting consequences for the magneto-oscillations expected when a magnetic field is applied perpendicular to the system surfaces. As the twist angle passes through special “arcless angles,” for which open Fermi arc states are absent at the interface, Fermi loops of states with no connection to bulk states appear. Such states have interesting resonance signatures in the optical conductivity of the system in a magnetic field perpendicular to the …

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Mar 2020 • Laser Applications in Microelectronic and Optoelectronic Manufacturing …, 2020

Optical waveguide on silicon made by zone melting method

Uriel Hanuka, Yair Zigman, Maor Tiferet, Zeev Zalevsky, Moshe Sinvani

In this paper we introduce a novel method of making micro-waveguides on silicon surface by the use of the Zone Refining Method. We produce the melting zone by a laser beam focused on the surface of a doped silicon slab to create a melting spot on its surface. By moving the melt zone across the silicon sample we can write a path of higher index of refraction on the silicon. The depth and the width of the waveguide can be determined by the wavelength and the spot diameter of the laser, respectively. We demonstrate the production of 1X4 μm2 channel on the silicon, by using 532 nm laser beam. This method can be applied in microelectronics for the manufacture of light waveguides on integrated optoelectronics ICs.

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Mar 2020 • Bulletin of the American Physical Society

Superconducting cavity QED: box modes for quantum control of qubits

Raina Olsen, Mohammadreza Rezaee, Eliahu Cohen, Ebrahim Karimi

Circuit QED uses two types of superconducting cavities: one-dimensional superconducting resonators that contain charge excitations, and two or three-dimensional regions of space between superconducting mirrors that contain photons. This latter type of cavity does not necessarily need to be enclosed. Any superconducting circuit acts as a cavity for the surrounding photonic modes with wavelengths on the order of the circuit geometry. Normally these are referred to as box modes, and treated primarily as a source of dissipation (except when a box mode frequency happens to be close to qubit frequencies). However, quantum transduction methods show that a system can be designed so that energy flows between modes at very different frequencies. We treat the problem of a superconducting qubit in a THz cavity by quantizing Maxwell’s equations, showing that the driven system is described by the linearized …

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Mar 2020 • Scientific reports

Generation and Manipulation of Superoscillatory Hotspots Using Virtual Fourier Filtering and CTF Shaping

Abhijit Sanjeev, Nadav Shabairou, Arrad Attar, Daniel Scherbaum, Yuval Kapellner, Moshe Sinvani, Zeev Zalevsky

Superoscillation is a technique that is used to produce a spot of light (known as ‘hotspot’) which is smaller than the conventional diffraction limit of a lens and even smaller than the optical wavelength. Over the past few years, several techniques have been realized for the generation of the superoscillatory hotspot. In this article, for the first time to the best of our knowledge, we propose a novel and a more efficient technique for producing superoscillation in microscopic imaging by shaping the Coherent Transfer Function (CTF) of a lens via virtual Fourier filtering followed by a phase retrieval algorithm. We design and realize a phase mask which when placed at the pupil plane of a diffraction-limited lens produces a superoscillatory hotspot with sidelobes properly matched to the field of view (FOV) required in microscopic imaging applications, ie hotspot always coexists with huge intense rings known as ‘sidebands …

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Mar 2020 • arXiv preprint arXiv:2003.01756

Electrostatic modulation of the lateral carrier density profile in field effect devices with non-linear dielectrics

Eylon Persky, Hyeok Yoon, Yanwu Xie, Harold Y Hwang, Jonathan Ruhman, Beena Kalisky

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.

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Mar 2020 • Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 12 (2 …, 2020

Advances in imaging strategies for in vivo tracking of exosomes

Oshra Betzer, Eran Barnoy, Tamar Sadan, Idan Elbaz, Cara Braverman, Zhuang Liu, Rachela Popovtzer

Exosomes have many biological functions as short‐ and long distance nanocarriers for cell‐to‐cell communication. They allow the exchange of complex information between cells, and thereby modulate various processes such as homeostasis, immune response and angiogenesis, in both physiological and pathological conditions. In addition, due to their unique abilities of migration, targeting, and selective internalization into specific cells, they are promising delivery vectors. As such, they provide a potentially new field in diagnostics and treatment, and may serve as an alternative to cell‐based therapeutic approaches. However, a major drawback for translating exosome treatment to the clinic is that current understanding of these endogenous vesicles is insufficient, especially in regards to their in vivo behavior. Tracking exosomes in vivo can provide important knowledge regarding their biodistribution, migration …

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Mar 2020 • Entropy 22 (3), 266, 2020

Some Notes on Counterfactuals in Quantum Mechanics

Avshalom C Elitzur, Eliahu Cohen

Counterfactuals, ie, events that could have occurred but eventually did not, play a unique role in quantum mechanics in that they exert causal effects despite their non-occurrence. They are therefore vital for a better understanding of quantum mechanics (QM) and possibly the universe as a whole. In earlier works, we have studied counterfactuals both conceptually and experimentally. A fruitful framework termed quantum oblivion has emerged, referring to situations where one particle seems to" forget" its interaction with other particles despite the latter being visibly affected. This framework proved to have significant explanatory power, which we now extend to tackle additional riddles. The time-symmetric causality employed by the Two State-Vector Formalism (TSVF) reveals a subtle realm ruled by “weak values,” already demonstrated by numerous experiments. They offer a realistic, simple and intuitively appealing explanation to the unique role of quantum non-events, as well as to the foundations of QM. In this spirit, we performed a weak value analysis of quantum oblivion and suggest some new avenues for further research. View Full-Text

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Mar 2020 • Microorganisms

The complexity of the holobiont in the Red Sea coral Euphyllia paradivisa under heat stress

Dalit Meron, Keren Maor-Landaw, Gal Eyal, Hila Elifantz, Ehud Banin, Yossi Loya, Oren Levy

The recognition of the microbiota complexity and their role in the evolution of their host is leading to the popularization of the holobiont concept. However, the coral holobiont (host and its microbiota) is still enigmatic and unclear. Here, we explore the complex relations between different holobiont members of a mesophotic coral Euphyllia paradivisa. We subjected two lines of the coral—with photosymbionts, and without photosymbionts (apo-symbiotic)—to increasing temperatures and to antibiotics. The different symbiotic states were characterized using transcriptomics, microbiology and physiology techniques. The bacterial community’s composition is dominated by bacteroidetes, alphaproteobacteria, and gammaproteobacteria, but is dependent upon the symbiont state, colony, temperature treatment, and antibiotic exposure. Overall, the most important parameter determining the response was whether the coral was a symbiont/apo-symbiotic, while the colony and bacterial composition were secondary factors. Enrichment Gene Ontology analysis of coral host’s differentially expressed genes demonstrated the cellular differences between symbiotic and apo-symbiotic samples. Our results demonstrate the significance of each component of the holobiont consortium and imply a coherent link between them, which dramatically impacts the molecular and cellular processes of the coral host, which possibly affect its fitness, particularly under environmental stress. View Full-Text

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Mar 2020 • ACS Catalysis

Ternary NiFeTiOOH catalyst for the oxygen evolution reaction: Study of the effect of the addition of Ti at different loadings

Wenjamin Moschkowitsch, Kapil Dhaka, Shmuel Gonen, Rinat Attias, Yoed Tsur, Maytal Caspary Toroker, Lior Elbaz

The world’s shift to the production of energy from sustainable sources requires the development of large energy storage. One of the best methods to store surplus energy produced from environmentally friendly methods is as elemental hydrogen, using electrolysis in alkaline electrolyzers. Currently, this technology is hampered by the sluggish oxygen evolution reaction (OER), which limits its overall efficiency and durability. One of the most popular directions is to develop cheap, durable, and active platinum-group-metal-free (PGM-free) catalysts. In this category, the benchmark catalyst is NiFeOOH. Here, synthetic, electrochemical, spectroscopic, and theoretical methods were used to design, synthesize, and investigate novel PGM-free catalysts with enhanced durability and activity. Using an easy and cheap one-step synthetic precipitation method, titanium atoms in various amounts were introduced in the NiFeOOH …

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Mar 2020 • Entropy

In Praise of Quantum Uncertainty

Eliahu Cohen, Avishy Carmi

Quantum uncertainty has a tremendous explanatory power. Coherent superposition, quantum equations of motion, entanglement, nonlocal correlations, dynamical nonlocality, contextuality, discord, counterfactual protocols, weak measurements, quantization itself, and even preservation of causality can be traced back to quantum uncertainty. We revisit and extend our previous works, as well as some other works of the community, in order to account for the above claims. Special emphasis is given to the connection between uncertainty and nonlocality, two notions which evolved quite independently and may seem distinct but, in fact, are tightly related. Indeterminism, or more precisely, locally consistent indeterminism, should be understood as the enabler of most quantum phenomena (and possibly all of them). View Full-Text

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Mar 2020 • Bioconjugate chemistry

Specific, sensitive, and quantitative detection of HER-2 mRNA breast cancer marker by fluorescent light-up hybridization probes

Abed Saady, Melissa Wojtyniak, Eli Varon, Verena Böttner, Noa Kinor, Yaron Shav-Tal, Christian Ducho, Bilha Fischer

Currently, there is demand for fluorescent oligonucleotide probes for diagnostic purposes. To address this necessity, we developed nucleosides containing a flexible spacer with an intercalating moiety at its end (NIC molecules). The intercalator is based on 4-hydroxybenzylidene imidazolinone (HBI), found in the Green Fluorescent Protein. We synthesized 20-mer oligonucleotides, ON1–ON4, incorporating the DMTr phosphorodiamidite monomer of dUHBI, 2, and the corresponding dUDFHBI, 5b, monomer. ON1–ON4 target the HER-2 mRNA breast cancer marker for the diagnostics of breast cancer subtype. Hybridization of ON1/ON2 and ON3/ON4 with complementary 2′-OMe-RNA resulted in emission at 462 and 481 nm, respectively, and up to 46-fold increase in fluorescence intensity. CD and 19F-NMR data indicated that HBI and DFHBI fluorophores bind as intercalators and stabilize the duplexes (up to ΔTm 6 …

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Mar 2020 • Chemical Reviews 120 (14), 6626-6683, 2020

Lithium–oxygen batteries and related systems: potential, status, and future

Won-Jin Kwak, Rosy, Daniel Sharon, Chun Xia, Hun Kim, Lee R Johnson, Peter G Bruce, Linda F Nazar, Yang-Kook Sun, Aryeh A Frimer, Malachi Noked, Stefan A Freunberger, Doron Aurbach

The goal of limiting global warming to 1.5 °C requires a drastic reduction in CO2 emissions across many sectors of the world economy. Batteries are vital to this endeavor, whether used in electric vehicles, to store renewable electricity, or in aviation. Present lithium-ion technologies are preparing the public for this inevitable change, but their maximum theoretical specific capacity presents a limitation. Their high cost is another concern for commercial viability. Metal–air batteries have the highest theoretical energy density of all possible secondary battery technologies and could yield step changes in energy storage, if their practical difficulties could be overcome. The scope of this review is to provide an objective, comprehensive, and authoritative assessment of the intensive work invested in nonaqueous rechargeable metal–air batteries over the past few years, which identified the key problems and guides directions to …

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Feb 2020 • Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XVII …, 2020

Remote optical sensing of neuronal tissue vibrations during regeneration

Ariel Halevi, Sharon Cohen, Nairous Farah, Asaf Shoval, Orit Shefi, Yossi Mandel, Zeev Zalevsky, Nisan Ozana

In this paper we propose a novel approach for remote speckle-based sensing of mechanical vibrations in the Hirudo medicinalis leech central nervous system (CNS) connective tissue. Using this method, spontaneous vibrations generated at the connective tissue following partial cut injury are continuously and remotely monitored. A laser beam illuminates the connective tissue and back scattered defocused patterns at the far field are captured by the camera. The spatialtemporal spontaneous vibrations of the connective are monitored by tracking the speckle spatial-temporal trajectory. After applying correlation-based analysis we were able to detect these vibrations of the connective tissue during recovery with respect to control measurements. This approach is the first step towards understanding the possible involvement of the tissue movements for the recovering process via mechanical vibrations sensing of the …

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Feb 2020 • ACS omega

Synthesis and Characterization of Free and Grafted N-Halamine Nanoparticles for Decomposition of Organic Dyes in an Aqueous Continuous Phase

Chen Gelber, Shlomo Margel

Synthetic organic dyes constitute a major pollutant in wastewater. Here, we describe the synthesis and characterization of N-halamine nanoparticles (NPs) for decomposition of organic dyes from contaminated wastewater. Cross-linked poly(methacrylamide) (PMAA) NPs of hydrodynamic diameters ranging from 11 ± 1 to 161 ± 31 nm were synthesized at room temperature by redox surfactant-free dispersion copolymerization of methacrylamide and the cross-linking monomer N,N′-methylenebis(acrylamide) in an aqueous continuous phase. The effect of various polymerization parameters on the diameter and size distribution of the formed NPs was studied. Additionally, thin coatings composed of cross-linked PMAA NPs were grafted onto oxidized corona-treated polypropylene (PP) films by redox graft polymerization of the monomers in the presence of oxidized PP films. The free and grafted NPs were converted to N …

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Feb 2020 • Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XVII …, 2020

Interaction-free quantum imaging

Yingwen Zhang, Lu Gao, Alicia Sit, Gal Amit, Hugo Larocque, Florence Grenapin, James L Harden, Robert W Boyd, Avshalom C Elitzur, Eliahu Cohen, Ebrahim Karimi

Quantum imaging attempts to exploit the quantum features of light in order to enhance one or more aspects of classical imaging. Here we focus on two quantum imaging schemes – ghost imaging and interaction-free imaging – and moreover, on their combination. After a brief overview of the subject we report the main result: a laboratory demonstration of a new imaging scheme termed Interaction-Free Ghost Imaging. We then explain its merits for the task of imaging various structured objects. Next, we discuss an outgrowth of this scheme used for the purpose of nonlocal quantum erasure. We conclude by mentioning some related, low-dose schemes (both quantum and quantum-inspired) for X-ray and gammaray sources.

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Feb 2020 • ACS applied materials & interfaces

Impact of SnF2 Addition on the Chemical and Electronic Surface Structure of CsSnBr3

Claudia Hartmann, Satyajit Gupta, Tatyana Bendikov, Xeniya Kozina, Thomas Kunze, Roberto Félix, Gary Hodes, Regan G Wilks, David Cahen, Marcus Bar

We report on the chemical and electronic structure of cesium tin bromide (CsSnBr3) and how it is impacted by the addition of 20 mol % tin fluoride (SnF2) to the precursor solution, using both surface-sensitive lab-based soft X-ray photoelectron spectroscopy (XPS) and near-surface bulk-sensitive synchrotron-based hard XPS (HAXPES). To determine the reproducibility and reliability of conclusions, several (nominally identically prepared) sample sets were investigated. The effects of deposition reproducibility, handling, and transport are found to cause significant changes in the measured properties of the films. Variations in the HAXPES-derived compositions between individual sample sets were observed, but in general, they confirm that the addition of 20 mol % SnF2 improves coverage of the titanium dioxide substrate by CsSnBr3 and decreases the oxidation of SnII to SnIV while also suppressing formation of …

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Feb 2020 • Journal of Molecular Liquids

Temperature evolution of the bulk nano-structure in a homologous series of room temperature ionic liquids

Diego Pontoni, Marco DiMichiel, Moshe Deutsch

We present x-ray scattering measurements on a homologous series of a model room-temperature ionic liquid (RTIL), [CnC1mim][NTf2]. The measurements span a broad range of cation alkyl chain lengths, n = 4 − 22, and temperatures, T = 293 − 393 K, not hitherto available for any RTIL. Thus, they support significantly deeper insights into the RTILs' structure. Resolution of the scattering curves into individual lines yields an accurate description of the RTILs' nanoscale-segregated structure, and its n and T evolution. The results strongly support a lateral packing of partly-overlapping, interdigitated, flexible alkyl chains within the segregated apolar domains. The domain thickness, and effective chain and overlap lengths, are determined for all n and T. These reveal that the n- and T-increasing overlap drives the observed counterintuitive layer-spacing contraction upon increasing T, while the effective chain lengths hardly …

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Feb 2020 • Cell reports

B cell diversification is uncoupled from SAP-mediated selection forces in chronic germinal centers within Peyer’s patches

Adi Biram, Eitan Winter, Alice E Denton, Irina Zaretsky, Bareket Dassa, Mats Bemark, Michelle A Linterman, Gur Yaari, Ziv Shulman

Antibodies secreted within the intestinal tract provide protection from the invasion of microbes into the host tissues. Germinal center (GC) formation in lymph nodes and spleen strictly requires SLAM-associated protein (SAP)-mediated T cell functions; however, it is not known whether this mechanism plays a similar role in mucosal-associated lymphoid tissues. Here, we find that in Peyer’s patches (PPs), SAP-mediated T cell help is required for promoting B cell selection in GCs, but not for clonal diversification. PPs of SAP-deficient mice host chronic GCs that are absent in T cell-deficient mice. GC B cells in SAP-deficient mice express AID and Bcl6 and generate plasma cells in proportion to the GC size. Single-cell IgA sequencing analysis reveals that these mice host few diversified clones that were subjected to mild selection forces. These findings demonstrate that T cell-derived help to B cells in PPs includes SAP …

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Feb 2020 • The Journal of Physical Chemistry C

Nitrogen-enriched porous benzimidazole-linked polymeric network for the adsorption of La (III), Ce (III), and Nd (III)

Moorthy Maruthapandi, John HT Luong, Aharon Gedanken

A porous benzimidazole-linked polymer, synthesized by a microwave-assisted procedure, exhibits an adsorption capacity of 760 mg/g, 700 mg/g, and 840 mg/g, respectively, for three rare earth ions, La (III), Ce (III), and Nd (III). The synthesized BINP polymer has an average pore size of 90 Å, a total pore volume of 0.03 cm3/g and a surface area of 21 m2/g. The electrostatic interaction between the positively charged polymer and the negatively charged rare-earth ions is responsible for the adsorption process, which is governed by the Langmuir or Freundlich isotherm. Adsorbed metal ions can be easily dissociated from the polymer, enabling polymer reusability with high recovery and efficiency.

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Feb 2020 • BRAIN

DMXL2 mutations impair autophagy and cause Ohtahara syndrome with progressive course (vol 142, pg 3876, 2019)

Alessandro Esposito, Antonio Falace, Matias Wagner, Moran Gal, Davide Mei, Valerio Conti, Tiziana Pisano, Davide Aprile, Maria Sabina Cerullo, Antonio De Fusco, Silvia Giovedi, Annette Seibt, Daniella Magen, Tilman Polster, Ayelet Eran, Sarah L Stenton, Chiara Fiorillo, Sarit Ravid, Ertan Mayatepek, Hava Hafner, Saskia Wortmann, Erez Y Levanon, Carla Marini, Hanna Mandel, Fabio Benfenati, Felix Distelmaier, Anna Fassio, Renzo Guerrini


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