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2022 • s Note: MDPI stays neutral with regard to jurisdictional claims in published …, 2022

Magnetite Nanoparticles: Synthesis and Applications in Optics and Nanophotonics. Materials 2022, 15, 2601

N Dudchenko, S Pawar, I Perelshtein, D Fixler

Magnetite nanoparticles with different surface coverages are of great interest for many applications due to their intrinsic magnetic properties, nanometer size, and definite surface morphology. Magnetite nanoparticles are widely used for different medical-biological applications while their usage in optics is not as widespread. In recent years, nanomagnetite suspensions, so-called magnetic ferrofluids, are applied in optics due to their magneto-optical properties. This review gives an overview of nanomagnetite synthesis and its properties. In addition, the preparation and application of magnetic nanofluids in optics, nanophotonics, and magnetic imaging are described.

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2022 • Methods

CRISPR technology

HJ Chung, YK Kang, PD Hsu, S Konermann, MH Porteus, A Hendel, J Clark, RO Bak, Ryan De, DJ Dellinger, R Kaiser, J Myerson, K Gagnon, M Damha, M Habibian, DT O’Reilly, Z Kartje

Recent patents relating to CRISPR methods and compositions for gene editing and therapeutic use.

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2022 • Laser & Photonics Reviews

Interpolarization Forward Stimulated Brillouin Scattering in Standard Single‐Mode Fibers

Hilel Hagai Diamandi, Gil Bashan, Yosef London, Kavita Sharma, Keren Shemer, Avi Zadok

Forward stimulated Brillouin scattering in standard single‐mode fibers draws increasing interest toward sensing and signal processing applications. The process takes place through two classes of guided acoustic modes: purely radial ones and torsional‐radial modes with twofold azimuthal symmetry. The latter case cannot be described in terms of scalar models alone. In this work, the polarization attributes of forward stimulated Brillouin scattering in single‐mode fibers are investigated in analysis and experiment. Torsional‐radial acoustic modes are stimulated by orthogonally polarized pump tones, a first such report in standard single‐mode fibers. The scattering of optical probe waves by torsional‐radial modes may take up the form of phase modulation, cross‐polarization coupling, or a combination of both, depending on polarization. Lastly, this analysis predicts that circular and orthogonal pump tones may …

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2022 • Frontiers in Endocrinology

ADAR1-dependent editing regulates human β cell transcriptome diversity during inflammation

Florian Szymczak, Roni Cohen-Fultheim, Sofia Thomaidou, Alexandra Coomans de Brachène, Angela Castela, Maikel Colli, Piero Marchetti, Erez Levanon, Decio Eizirik, Arnaud Zaldumbide

Methods: Using high-throughput RNA sequencing data from human islets and EndoC-βH1 cells exposed to IFNα or IFNγ/IL1β, we evaluated the role of ADAR1 in human pancreatic β cells and determined the impact of the type 1 diabetes pathophysiological environment on ADAR1-dependent RNA editing.Results: We show that both IFNα and IFNγ/IL1β stimulation promote ADAR1 expression and increase the A-to-I RNA editing of Alu-Containing mRNAs in EndoC-βH1 cells as well as in primary human islets.Discussion: We demonstrate that ADAR1 overexpression inhibits type I interferon response signaling, while ADAR1 silencing potentiates IFNα effects. In addition, ADAR1 overexpression triggers the generation of alternatively spliced mRNAs, highlighting a novel role for ADAR1 as a regulator of the β cell transcriptome under inflammatory conditions.

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2022 • RSC Advances

Prospect of making XPS a high-throughput analytical method illustrated for a Cu x Ni 1− x O y combinatorial material library

Lucas CW Bodenstein-Dresler, Adi Kama, Johannes Frisch, Claudia Hartmann, Anat Itzhak, Regan G Wilks, David Cahen, Marcus Bär


2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022

Forward Brillouin Scattering Spectra in Coated Single-Mode Fibers

Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan

The analysis of forward stimulated Brillouin scattering is extended to standard single-mode fibers with coating layers. The cutoff frequencies, linewidths, and transverse profiles of the guided acoustic modes are modified by the presence of the coating layer and by its mechanical properties. The solutions are generally more complex than those of bare, uncoated fibers. Nevertheless, the boundary conditions can be brought into the form of matrix coefficients and solved to obtain the guided modes of the coated fibers. The forward stimulated Brillouin scattering of coated fibers is highly sensitive of submicron variations in the thickness of the coating layer, due to interference effects. Some modes are more sensitive to such variations than others. In contrast to bare fibers, the forward Brillouin scattering linewidths of coated fibers do not maintain a one-to-one correspondence with the mechanical impedance of media outside …

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2022 • Proc. of SPIE Vol

Characterization of second-harmonic generation in silver nanoparticles for spontaneous parametric down-conversion

Ariel Ashkenazy, Eliahu Cohen, Dror Fixler

Energy-time entangled photon pairs (EPPs), which are at the heart of numerous quantum light applications, are commonly generated in nonlinear crystals. Some highly sensitive quantum applications require the use of ultra-broadband entangled photons that cannot be generated in nonlinear crystals due to phase-matching requirements. Here, we investigate the possibility of using metallic nanoparticles (MNPs) as a means for generating entangled photons through spontaneous parametric down-conversion (SPDC). MNPs are known for their strong light-matter coupling at their localized surfaceplasmon resonance, and since the propagation length through them is negligible relative to optical wavelengths, we consider them as excellent candidates to serve as non-phase matched sources of ultra-broadband entangled photons.To that end, we report experimental results of classical-light second-harmonic generation …

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2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022

Spontaneous Forward Brillouin Scattering in Standard Single-Mode Fibers

Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan

This chapter studies spontaneous scattering of light in single-mode fibers, due to the photoelastic perturbations associated with the oscillations of guided acoustic modes. The acoustic modes, in this case, are not stimulated by the optical fields being observed. Instead, they may be of thermal origin or driven by other optical field components than those monitored. Scattering is formulated in terms of nonlinear polarization terms and nonlinear wave equations for the evolution of the spectral sidebands of an input optical field. In the case of radial guided acoustic modes, photoelastic scattering of the optical field results in its phase modulation. By contrast, torsional-radial acoustic modes may induce phase modulation, coupling to the orthogonal polarization, or a combination of both, depending on the state of polarization of the input optical field. The strength of modulation is quantified in terms of a nonlinear coefficient …

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2022 • Physical Chemistry Chemical Physics

Electron transport via tyrosine-doped oligo-alanine peptide junctions: role of charges and hydrogen bonding

Cunlan Guo, Yulian Gavrilov, Satyajit Gupta, Tatyana Bendikov, Yaakov Levy, Ayelet Vilan, Israel Pecht, Mordechai Sheves, David Cahen

A way of modulating the solid-state electron transport (ETp) properties of oligopeptide junctions is presented by charges and internal hydrogen bonding, which affect this process markedly. The ETp properties of a series of tyrosine (Tyr)-containing hexa-alanine peptides, self-assembled in monolayers and sandwiched between gold electrodes, are investigated in response to their protonation state. Inserting a Tyr residue into these peptides enhances the ETp carried via their junctions. Deprotonation of the Tyr-containing peptides causes a further increase of ETp efficiency that depends on this residue’s position. Combined results of molecular dynamics simulations and spectroscopic experiments suggest that the increased conductance upon deprotonation is mainly a result of enhanced coupling between the charged C-terminus carboxylate group and the adjacent Au electrode. Moreover, intra-peptide hydrogen …

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2022 • Advanced Materials Interfaces

Surface Interactions of Oxygen Suffice to P‐Dope the Halide Perovskites

Ansuman Halder, Anat Itzhak, Eli Rosh Hodesh, Shay Tirosh, David Cahen

Attempts to dope halide perovskites (HaPs) extrinsically have been mostly unsuccessful. Still, oxygen (O2) is an efficient p‐dopant for polycrystalline HaP films. To an extent, this doping is reversible, i.e., the films can be de‐doped by decreasing the O2 partial pressure. Here results are reported, aimed at understanding the mechanism of such reversible doping, as it has been argued that doping involves interaction of oxygen with defects inside bulk HaP. These experimental results clearly point out that O2‐surface interactions suffice to dope the bulk of the films. Such behavior fits what is known for other polycrystalline semiconductors, where surface charge transfer‐adducts can form and be removed. Thus, controlling the O2 partial pressure to which the HaP film is exposed, can, after proper encapsulation, achieve the desired bulk doping of the film.

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2022 • Physical Chemistry Chemical Physics

The effects of thermal treatment and irradiation on the chemical properties of natural diamonds

Ira Litvak, Haim Cohen, Sharon Ruthstein, Yaakov Anker, Avner Cahana

The modification of nitrogen-contaminated diamonds into color-enhanced diamonds is usually achieved by irradiation and thermal treatment (annealing). These treatments affect nitrogen contamination chemical bonding, vacancy concentration, and atom orientation centers in the diamond lattice. In this study, natural diamonds were subjected to irradiation and thermal annealing color enhancement treatments to produce green, blue, and yellow fancy diamonds. The study followed the changes that occur during treatment relying on visual assessment, fluorescence, UV-vis, FTIR, and EPR spectroscopy to characterize paramagnetic centers. The results indicated that diamonds containing high levels of nitrogen contamination presented a relatively high carbon-centered radical concentration. Two paramagnetic groups with different g-values were found, namely, low g-value centers of 2.0017-2.0027 and high g-value …

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2022 • Proc. of SPIE Vol

Quantum hard x-ray microscopy with undetected photons

Haim Aknin, Sharon Shwartz

We explore the possibility for implementing nanoscale quantum imaging based on the concept of undetected photons with a pumping beam at x-ray wavelengths. Our proposed scheme exploits the nearly four order of magnitude angular magnification that is a result of the process of the effect of extreme non-degenerate spontaneous down conversion from xrays into optical radiation, which is used for the generation of entangled photon pairs with one x-ray photon and one visible photon. In our scheme the x-ray photons interact with the object and the visible do not interact with the object, but in contrast to other schemes like ghost imaging, only the visible photons are detected. The scheme is sensitive to both the amplitude and the phase variations and can provide resolutions down to a few nanometers, hence can be used as a powerful tool for nanoscale imaging. In the present configuration, the scheme requires very …

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2022

Prospect of making XPS a high-throughput analytical method illustrated for a CuₓNi₁₋ ₓOy combinatorial material library

Lucas CW Bodenstein-Dresler, Adi Kama, Johannes Frisch, Claudia Hartmann, Anat Itzhak, Regan G Wilks, David Cahen, Marcus Bär

Combinatorial material science crucially depends on robust, high-throughput characterization methods. While X-ray photoelectron spectroscopy (XPS) may provide detailed information about chemical and electronic properties, it is a time-consuming technique and, therefore, is not viewed as a high-throughput method. Here we present preliminary XPS data of 169 measurement spots on a combinatorial 72 × 72 cm² CuₓNi₁₋ₓOy compositional library to explore how characterization and evaluation routines can be optimized to improve throughput in XPS for combinatorial studies. In particular, two quantification approaches are compared. We find that a simple integration (of XPS peak regions) approach is suited for fast evaluation of, in the example system, the [Cu]/([Cu] + [Ni]) ratio. Complementary to that, the time-consuming (XPS peak-) fit approach provides additional insights into chemical speciation and oxidation state changes, without a large deviation of the [Cu]/([Cu] + [Ni]) ratio. This insight suggests exploiting the fast integration approach for ‘real time’ analysis during XPS data collection, paving the way for an ‘on-the-fly’ selection of points of interest (i.e., areas on the sample where sudden composition changes have been identified) for detailed XPS characterization. Together with the envisioned improvements when going from laboratory to synchrotron-based excitation sources, this will shorten the analysis time sufficiently for XPS to become a realistic characterization option for combinatorial material science.

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2022 • Evolution, Biodiversity and a Reassessment of the Hygiene Hypothesis, 105-140, 2022

Regulation of host immunity by the gut microbiota

Hannah Partney, Nissan Yissachar

Constant exposure to diverse microorganisms has accompanied human evolution and continues to shape immunological development throughout life. In mucosal tissues, both innate and adaptive arms of the immune system are required to support healthy mutualistic interactions with the resident microbiota, while aggressively fighting pathogenic infections. Technological breakthroughs over the past decade facilitated groundbreaking discoveries that transformed our understanding of intestinal immunology and established the gut microbiota as a critical factor that shapes immunological development and function. Indeed, alterations to microbiota composition (dysbiosis) are associated with a wide array of human diseases, including autoimmune diseases, chronic inflammation, the metabolic syndrome, and cancer. In this chapter, we discuss fundamental concepts that underlie microbiota-immune system crosstalks …

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2022 • Magnetochemistry 8 (1), 3, 2022

The Advantages of EPR Spectroscopy in Exploring Diamagnetic Metal Ion Binding and Transfer Mechanisms in Biological Systems

Shelly Meron, Yulia Shenberger, Sharon Ruthstein

Electron paramagnetic resonance (EPR) spectroscopy has emerged as an ideal biophysical tool to study complex biological processes. EPR spectroscopy can follow minor conformational changes in various proteins as a function of ligand or protein binding or interactions with high resolution and sensitivity. Resolving cellular mechanisms, involving small ligand binding or metal ion transfer, is not trivial and cannot be studied using conventional biophysical tools. In recent years, our group has been using EPR spectroscopy to study the mechanism underlying copper ion transfer in eukaryotic and prokaryotic systems. This mini-review focuses on our achievements following copper metal coordination in the diamagnetic oxidation state, Cu(I), between biomolecules. We discuss the conformational changes induced in proteins upon Cu(I) binding, as well as the conformational changes induced in two proteins involved in Cu(I) transfer. We also consider how EPR spectroscopy, together with other biophysical and computational tools, can identify the Cu(I)-binding sites. This work describes the advantages of EPR spectroscopy for studying biological processes that involve small ligand binding and transfer between intracellular proteins.

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2022 • Soft Matter

Network model of active elastic shells swollen by hydrostatic pressure

Ajoy Maji, Yitzhak Rabin

Many organisms have an elastic skeleton that consists of a closed shell of epithelial cells that is filled with fluid, and can actively regulate both elastic forces in the shell and hydrostatic pressure inside it. In this work we introduce a simple network model of such pressure-stabilized active elastic shells in which cross-links are represented by material points connected by non-linear springs of some given equilibrium lengths and spring constants. We mimic active contractile forces in the system by changing the parameters of randomly chosen springs and use computer simulations to study the resulting local and global deformation dynamics of the network. We elucidate the statistical properties of these deformations by computing the corresponding distributions and correlation functions. We show that pressure-induced stretching of the network introduces coupling between its local and global behavior: while the network …

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2022 • s Note: MDPI stays neutral with regard to jurisdictional claims in published …, 2022

Nitrogen Structure Determination in Treated Fancy Diamonds via EPR Spectroscopy. Crystals 2022, 12, 1775

I Litvak, A Cahana, Y Anker, S Ruthstein, H Cohen

Color induction in nitrogen-contaminated diamonds was carried out via various procedures that involve irradiation, thermal treatments (annealing), and more. These treatments affect vacancy defect production and atom orientation centers in the diamond lattice. Natural diamonds underwent color enhancement treatments in order to produce green, blue, and yellow fancy diamonds. The aim of this study was to follow the changes occurring during the treatment, mainly by EPR spectroscopy, which is the main source for the determination of the effect of paramagnetic centers (carbon-centered radicals) on the color centers produced via the treatments, but also via visual assessment, fluorescence, UV-vis, and FTIR spectroscopy. The results indicate that diamonds containing high levels of nitrogen contamination are associated with high carbon-centered radical concentrations. Four paramagnetic center structures (N1, N4, and P2/W21) were generated by the treatment. It is suggested that the N4 structure correlates with the formation of blue color centers, whereas yellow color centers are attributed to the presence of N1 species. While to produce blue and yellow colors, a thermal treatment is needed after irradiation, for treated green diamonds, no thermal treatment is needed (only irradiation).

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2022 • APS March Meeting Abstracts

Designing chromium (IV) molecular color centers

Daniel Laorenza, Arailym Kairalapova, Samuel Bayliss, Tamar Goldzak, Samuel Greene, Leah Weiss, Pratiti Deb, Peter Mintun, Kelsey Collins, David Awschalom, Timothy Berkelbach, Danna Freedman

Transition metal-based molecular spins are a promising class of chemically tunable quantum bits (qubits), providing precise control over both the physical and electronic structure within a scalable qubit platform. However, molecular systems typically lack an optically addressable ground state spin. To introduce this valuable resource into molecular spins, we recently created a series of chromium (IV) compounds with the desired optical-spin interface through bottom-up design [1]. Here, we illustrate the versatility of this methodology to generate designer molecular color centers by modifying the organic moieties, or ligands, directly bound to the chromium (IV) site. Variation of the surrounding ligands across six unique systems modulates both the optical emission and ground state zero-field splitting (ZFS) energies. Moreover, the small ZFS values allowed for coherent spin manipulation at X-band microwave frequency …

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2022 • s Note: MDPI stays neutral with regard to jurisdictional claims in published …, 2022

Simultaneous Noninvasive Detection and Therapy of Atherosclerosis Using HDL Coated Gold Nanorods. Diagnostics 2022, 12, 577

R Ankri, D Leshem-Lev, H Duadi, E Harari, M Motiei, E Hochhauser, EI Lev, D Fixler

Cardiovascular disease (CVD) is a major cause of death and disability worldwide. A real need exists in the development of new, improved therapeutic methods for treating CVD, while major advances in nanotechnology have opened new avenues in this field. In this paper, we report the use of gold nanoparticles (GNPs) coated with high-density lipoprotein (HDL)(GNP-HDL) for the simultaneous detection and therapy of unstable plaques. Based on the well-known HDL cardiovascular protection, by promoting the reverse cholesterol transport (RCT), injured rat carotids, as a model for unstable plaques, were injected with the GNP-HDL. Noninvasive detection of the plaques 24 h post the GNP injection was enabled using the diffusion reflection (DR) method, indicating that the GNP-HDL particles had accumulated in the injured site. Pathology and noninvasive CT measurements proved the recovery of the injured artery treated with the GNP-HDL. The DR of the GNP-HDL presented a simple and highly sensitive method at a low cost, resulting in simultaneous specific unstable plaque diagnosis and recovery.

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2022 • Energy & Environmental Science

Light-induced beneficial ion accumulation for high-performance quasi-2D perovskite solar cells

Xiaomei Lian, Lijian Zuo, Bowen Chen, Biao Li, Haotian Wu, Shiqi Shan, Gang Wu, Xuegong Yu, Qi Chen, Liwei Chen, Deren Yang, David Cahen, Hongzheng Chen

Ion migration and subsequent accumulation at interfaces, driven by the built-in potential (Vbi), are intrinsic properties of halide perovskite solar cells (PVSCs), which mostly decrease device performance. To address this issue, we constructed favorable ion accumulation in perovskite solar cell by illumination to improve quasi-2D PVSCs performance. This design dramatically improves the photo-carrier collection and enables significant device performance improvement from 14.6% to 19.05%, one of the best results for quasi-2D PVSCs. We argue that the light-triggered favorable ion accumulation originates from 1) photo-induced quasi-fermi level splitting that compensates the Vbi, so as to avoid the ion accumulation that decreases Vbi, and 2) the light intensity distribution-induced uneven ion potential further drives the segregation of mobile ions towards favorable ion accumulation, decreasing any I- gradient between …

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2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022

Concluding Perspectives

Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan

The final chapter of the book provides a brief recap of forward Brillouin scattering in standard optical fibers, directions for possible further research, and the prospects and challenges associated with technological applications of the effect.

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