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May 2023 • arXiv preprint arXiv:2205.08563

Majorana-Weyl cones in ferroelectric superconductors

Hennadii Yerzhakov, Roni Ilan, Efrat Shimshoni, Jonathan Ruhman

Topological superconductors are predicted to exhibit outstanding phenomena, including non-abelian anyon excitations, heat-carrying edge states, and topological nodes in the Bogoliubov spectra. Nonetheless, and despite major experimental efforts, we are still lacking unambiguous signatures of such exotic phenomena. In this context, the recent discovery of coexisting superconductivity and ferroelectricity in lightly doped and ultra clean SrTiO opens new opportunities. Indeed, a promising route to engineer topological superconductivity is the combination of strong spin-orbit coupling and inversion-symmetry breaking. Here we study a three-dimensional parabolic band minimum with Rashba spin-orbit coupling, whose axis is aligned by the direction of a ferroelectric moment. We show that all of the aforementioned phenomena naturally emerge in this model when a magnetic field is applied. Above a critical Zeeman field, Majorana-Weyl cones emerge regardless of the electronic density. These cones manifest themselves as Majorana arcs states appearing on surfaces and tetragonal domain walls. Rotating the magnetic field with respect to the direction of the ferroelectric moment tilts the Majorana-Weyl cones, eventually driving them into the type-II state with Bogoliubov Fermi surfaces. We then consider the consequences of the orbital magnetic field. First, the single vortex is found to be surrounded by a topological halo, and is characterized by two Majorana zero modes: One localized in the vortex core and the other on the boundary of the topological halo. For a finite density of vortices forming close enough to the upper critical field, these halos …

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May 2023 • Journal of Biomedical Optics

Imaging the rotational mobility of carbon dot-gold nanoparticle conjugates using frequency domain wide-field time-resolved fluorescence anisotropy

Gilad Yahav, Shweta Pawar, Yitzchak Weber, Bar Atuar, Hamootal Duadi, Dror Fixler

SignificanceWide-field measurements of time-resolved fluorescence anisotropy (TR-FA) provide pixel-by-pixel information about the rotational mobility of fluorophores, reflecting changes in the local microviscosity and other factors influencing the fluorophore’s diffusional motion. These features offer promising potential in many research fields, including cellular imaging and biochemical sensing, as demonstrated by previous works. Nevertheless, θ imaging is still rarely investigated in general and in carbon dots (CDs) in particular.AimTo extend existing frequency domain (FD) fluorescence lifetime (FLT) imaging microscopy (FLIM) to FD TR-FA imaging (TR-FAIM), which produces visual maps of the FLT and θ, together with the steady-state images of fluorescence intensity (FI) and FA (r).

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May 2023 • 243rd ECS Meeting with the 18th International Symposium on Solid Oxide Fuel Cells (SOFC-XVIII)

High Surface Area Metal Carbide Aerogels as Durable Catalyst for the Hydrogen Evolution Reaction

Lior Elbaz, Oran Lori

May 2023 • Journal of Biomedical Optics

Imaging the rotational mobility of carbon dot-gold nanoparticle conjugates using frequency domain wide-field time-resolved fluorescence anisotropy

Gilad Yahav, Shweta Pawar, Yitzchak Weber, Bar Atuar, Hamootal Duadi, Dror Fixler

SignificanceWide-field measurements of time-resolved fluorescence anisotropy (TR-FA) provide pixel-by-pixel information about the rotational mobility of fluorophores, reflecting changes in the local microviscosity and other factors influencing the fluorophore’s diffusional motion. These features offer promising potential in many research fields, including cellular imaging and biochemical sensing, as demonstrated by previous works. Nevertheless, θ imaging is still rarely investigated in general and in carbon dots (CDs) in particular.AimTo extend existing frequency domain (FD) fluorescence lifetime (FLT) imaging microscopy (FLIM) to FD TR-FA imaging (TR-FAIM), which produces visual maps of the FLT and θ, together with the steady-state images of fluorescence intensity (FI) and FA (r).ApproachThe proof of concept of the combined FD FLIM/ FD TR-FAIM was validated on seven fluorescein solutions with increasing …

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May 2023 • ACS ES&T Engineering

Plant-Derived Nitrogen-Doped Carbon Dots as an Effective Fertilizer for Enhanced Strawberry Growth and Yield

Belal Abu Salha, Arumugam Saravanan, Moorthy Maruthapandi, Ilana Perelshtein, Aharon Gedanken

Plant-derived carbon dots have superior light absorption and intrinsic fluorescence properties. In this work, we have prepared nitrogen-doped carbon dots (N-CDs) from Piper betle leaves using a simple hydrothermal method. The synthesized N-CDs were characterized by various techniques such as high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, and photoluminescence. The N-CDs further proved to have systemic effects on the growth of strawberries compared with irrigating the strawberry plants with water and regular nutrients. The strawberry plants treated with N-CDs exhibited an increase in chlorophyll content of about 24.7%, which was reflected in increased carbohydrate content of approximately 48.61% compared to control plants. Also, N-CD-treated strawberry plants showed increased secondary metabolites (phenolics) compared to control …

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May 2023 • arXiv preprint arXiv:2305.05258

FEL stochastic spectroscopy revealing silicon bond softening dynamics

Dario De Angelis, Emiliano Principi, Filippo Bencivenga, Daniele Fausti, Laura Foglia, Yishay Klein, Michele Manfredda, Riccardo Mincigrucci, Angela Montanaro, Emanuele Pedersoli, Jacopo Stefano Pelli Cresi, Giovanni Perosa, Kevin C Prince, Elia Razzoli, Sharon Shwartz, Alberto Simoncig, Simone Spampinati, Cristian Svetina, Jakub Szlachetko, Alok Tripathi, Ivan A Vartanyants, Marco Zangrando, Flavio Capotondi

Time-resolved X-ray Emission/Absorption Spectroscopy (Tr-XES/XAS) is an informative experimental tool sensitive to electronic dynamics in materials, widely exploited in diverse research fields. Typically, Tr-XES/XAS requires X-ray pulses with both a narrow bandwidth and sub-picosecond pulse duration, a combination that in principle finds its optimum with Fourier transform-limited pulses. In this work, we explore an alternative xperimental approach, capable of simultaneously retrieving information about unoccupied (XAS) and occupied (XES) states from the stochastic fluctuations of broadband extreme ultraviolet pulses of a free-electron laser. We used this method, in combination with singular value decomposition and Tikhonov regularization procedures, to determine the XAS/XES response from a crystalline silicon sample at the L2,3-edge, with an energy resolution of a few tens of meV. Finally, we combined this spectroscopic method with a pump-probe approach to measure structural and electronic dynamics of a silicon membrane. Tr-XAS/XES data obtained after photoexcitation with an optical laser pulse at 390 nm allowed us to observe perturbations of the band structure, which are compatible with the formation of the predicted precursor state of a non-thermal solid-liquid phase transition associated with a bond softening phenomenon.

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May 2023 • IEEE Transactions on Applied Superconductivity

Energy Storing and Fault Current Limiting in a Unified Superconducting Magnetic Device

Y Nikulshin, A Kafri, Y Yeshurun, S Wolfus

This work describes a novel concept for unifying Superconducting Magnetic Energy Storage (SMES) and an inductive-type Fault Current Limiter (FCL). A single superconducting coil is used both as an energy source for the operation of the SMES and as the field source for saturating the magnetic cores in the FCL. A possible geometry model for the implementation of this concept is suggested and a test case in an 11 kV, 10 MVA network is described for a fully, and 50% charged SMES states. Results show that the Saturated Cores FCL exhibits low insertion impedance and high limiting ratio in both scenarios. The unified SMES-FCL device saves major resources by making the superconducting coil a dual-purpose source, thus opening the door for an easier and efficient implementation of SMES and FCL technologies.

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May 2023 • Nano Letters

Hierarchically Porous Few-Layer Carbon Nitride and Its High H+ Selectivity for Efficient Photocatalytic Seawater Splitting

Shi-Tian Xiao, Rui Yin, Lu Wu, Si-Ming Wu, Ge Tian, Menny Shalom, Li-Ying Wang, Yi-Tian Wang, Fu-Fei Pu, Hannah-Noa Barad, Fazhou Wang, Xiao-Yu Yang

Photocatalysts for seawater splitting are severely restricted because of the presence of multiple types of ions in seawater that cause corrosion and deactivation. As a result, new materials that promote adsorption of H+ and hinder competing adsorption of metal cations should enhance utilization of photogenerated electrons on the catalyst surface for efficient H2 production. One strategy to design advanced photocatalysts involves introduction of hierarchical porous structures that enable fast mass transfer and creation of defect sites that promote selective hydrogen ion adsorption. Herein, we used a facile calcination method to fabricate the macro–mesoporous C3N4 derivative, VN-HCN, that contains multiple nitrogen vacancies. We demonstrated that VN-HCN has enhanced corrosion resistance and elevated photocatalytic H2 production performance in seawater. Experimental results and theoretical calculations …

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May 2023 • Advanced Energy Materials

Ion Flux Regulation through PTFE Nanospheres Impregnated in Glass Fiber Separators for Long‐Lived Lithium and Sodium Metal Batteries

Yajie Liu, Zhixin Tai, Ido Rozen, Zhipeng Yu, Ziyu Lu, Alec P LaGrow, Oleksandr Bondarchuk, Qingqing Chen, Gil Goobes, Yi Li, Lifeng Liu

Practical implementation of alkali metal batteries currently still faces formidable challenges because of the dendrite growth upon continuous charge/discharge processes and the associated unstable solid–electrolyte interphase. Herein, it is reported that dendrites can be fundamentally mitigated in lithium and sodium metal batteries by regulating the Li+ and Na+ flux using a glass fiber (GF) separator impregnated with polytetrafluoroethylene nanospheres (PTFE‐NSs), which results in homogeneous deposition of Li and Na during charging. The COMSOL Multiphysics simulations reveal that the introduction of negatively charged PTFE‐NSs into the GF separator enhances the local electric field near the anode, thereby boosting the transfer of cations. It is demonstrated that Li//Li and Na//Na symmetric cells utilising a PTFE‐GF separator show outstanding cycle stability of 1245 and 2750 h, respectively, at 0.5 mA cm−2 …

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May 2023 • Scientific Reports

2D tunable all-solid-state random laser in the visible

Bhupesh Kumar, Ran Homri, Patrick Sebbah

A two-dimensional (2D) solid-state random laser emitting in the visible is demonstrated, in which optical feedback is provided by a controlled disordered arrangement of air-holes in a dye-doped polymer film. We find an optimal scatterer density for which threshold is minimum and scattering is the strongest. We show that the laser emission can be red-shifted by either decreasing scatterer density or increasing pump area. We show that spatial coherence is easily controlled by varying pump area. Such a 2D random laser provides with a compact on-chip tunable laser source and a unique platform to explore non-Hermitian photonics in the visible.

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May 2023 • Physical Review A

High-spectral-resolution absorption measurements with free-electron lasers using ghost spectroscopy

Yishai Klein, Alok K Tripathi, Edward Strizhevsky, Flavio Capotondi, Dario De Angelis, Luca Giannessi, Matteo Pancaldi, Emanuele Pedersoli, Kevin C Prince, Or Sefi, Young Yong Kim, Ivan A Vartanyants, Sharon Shwartz

We demonstrate a simple and robust high-resolution ghost spectroscopy approach for x-ray and extreme ultraviolet transient absorption spectroscopy at free-electron laser sources. To retrieve the sample response, our approach requires only an online spectrometer before the sample and a downstream bucket detector. We validate the method by measuring the absorption spectrum of silicon, silicon carbide, and silicon nitride membranes in the vicinity of the silicon L 2, 3 edge and by comparing the results with standard techniques for absorption measurements. Moreover, we show that ghost spectroscopy allows the high-resolution reconstruction of the sample spectral response to optical pumps using a coarse energy scan with self-amplified spontaneous emission radiation.

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May 2023 • arXiv preprint arXiv:2305.04888

Phase diagram of the quantum Hall state in bilayer graphene

Udit Khanna, Ke Huang, Ganpathy Murthy, HA Fertig, Kenji Watanabe, Takashi Taniguchi, Jun Zhu, Efrat Shimshoni

Bilayer graphene exhibits a rich phase diagram in the quantum Hall regime, arising from a multitude of internal degrees of freedom, including spin, valley, and orbital indices. The variety of fractional quantum Hall states between filling factors suggests, among other things, a quantum phase transition between valley-unpolarized and polarized states at a perpendicular electric field . We find the behavior of with changes markedly as is reduced. At , may even vanish when is sufficiently small. We present a theoretical model for lattice-scale interactions which explains these observations; surprisingly, both repulsive and attractive components in the interactions are required. Within this model we analyze the nature of the state as a function of the magnetic and electric fields, and predict that valley-coherence may emerge for in the high regime. This suggests the system supports Kekule bond-ordering, which could in principle be verified via STM measurements.

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May 2023 • Bioengineering & Translational Medicine

Micelle encapsulation zinc‐doped copper oxide nanocomposites reverse Olaparib resistance in ovarian cancer by disrupting homologous recombination repair

Jingyan Yi, Xin Luo, Jinshan Xing, Aharon Gedanken, Xiukun Lin, Chunxiang Zhang, Gan Qiao

Micelle Encapsulation Zinc‐doped copper oxide nanocomposites (MEnZn‐CuO NPs) is a novel doped metal nanomaterial prepared by our group based on Zinc doped copper oxide nanocomposites (Zn‐CuO NPs) using non‐micellar beam. Compared with Zn‐CuO NPs, MEnZn‐CuO NPs have uniform nanoproperties and high stability. In this study, we explored the anticancer effects of MEnZn‐CuO NPs on human ovarian cancer cells. In addition to affecting cell proliferation, migration, apoptosis and autophagy, MEnZn‐CuO NPs have a greater potential for clinical application by inducing HR repair defects in ovarian cancer cells in combination with poly (ADP‐ribose) polymerase inhibitors for lethal effects.

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May 2023 • arXiv preprint arXiv:2305.12468

High-resolution computed tomography with scattered x-ray radiation and a single pixel detector

A Ben Yehuda, O Sefi, Y Klein, RH Shukrun, H Schwartz, E Cohen, S Shwartz

X-ray imaging is a prevalent technique for non-invasively visualizing the interior of the human body and opaque instruments. In most commercial x-ray modalities, an image is formed by measuring the x-rays that pass through the object of interest. However, despite the potential of scattered radiation to provide additional information about the object, it is often disregarded due to its inherent tendency to cause blurring. Consequently, conventional imaging modalities do not measure or utilize these valuable data. In contrast, we propose and experimentally demonstrate a high-resolution technique for x-ray computed tomography (CT) that measures scattered radiation by exploiting computational ghost imaging (CGI). We show that our method can provide sub-200 {\mu}m resolution, exceeding the capabilities of most existing x-ray imaging modalities. Our research reveals a promising technique for incorporating scattered radiation data in CT scans to improve image resolution and minimize radiation exposure for patients. The findings of our study suggest that our technique could represent a significant advancement in the fields of medical and industrial imaging, with the potential to enhance the accuracy and safety of diagnostic imaging procedures.

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May 2023 • Journal of Functional Biomaterials

Engineered Cross-Linked Silane with Urea Polymer Thin Durable Coatings onto Polymeric Films for Controlled Antiviral Release of Activated Chlorine and Essential Oils

Elisheva Sasson, Omer Agazani, Eyal Malka, Meital Reches, Shlomo Margel

In March 2020, the World Health Organization announced a pandemic attributed to SARS-CoV-2, a novel beta-coronavirus, which spread widely from China. As a result, the need for antiviral surfaces has increased significantly. Here, the preparation and characterization of new antiviral coatings on polycarbonate (PC) for controlled release of activated chlorine (Cl+) and thymol separately and combined are described. Thin coatings were prepared by polymerization of 1-[3-(trimethoxysilyl)propyl] urea (TMSPU) in ethanol/water basic solution by modified Stöber polymerization, followed by spreading the formed dispersion onto surface-oxidized PC film using a Mayer rod with appropriate thickness. Activated Cl-releasing coating was prepared by chlorination of the PC/SiO2-urea film with NaOCl through the urea amide groups to form a Cl-amine derivatized coating. Thymol releasing coating was prepared by linking thymol to TMSPU or its polymer via hydrogen bonds between thymol hydroxyl and urea amide groups. The activity towards T4 bacteriophage and canine coronavirus (CCV) was measured. PC/SiO2-urea-thymol enhanced bacteriophage persistence, while PC/SiO2-urea-Cl reduced its amount by 84%. Temperature-dependent release is presented. Surprisingly, the combination of thymol and chlorine had an improved antiviral activity, reducing the amount of both viruses by four orders of magnitude, indicating synergistic activity. For CCV, coating with only thymol was inactive, while SiO2-urea-Cl reduced it below a detectable level.

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Apr 2023 • Photonics

Quantitative Phase Contrast Microscopy with Optimized Partially Coherent Illumination

Kequn Zhuo, Yang Wang, Ying Ma, Sha An, Zeev Zalevsky, Juanjuan Zheng, Peng Gao

Apr 2023 • Optics Continuum

Towards in-vivo detection of amyloid− β and tau in human CSF using machine learning based Raman spectroscopy

Noam Lhiyani, Abhijit Sanjeev, Avshalom Mor, Yevgeny Beiderman, Javier Garcia, Zeev Zalevsky

This paper aims to present initial proof of concept of a non-invasive early diagnostic tool for Alzheimer disease (AD). The approach is based on the identification using Raman spectroscopy and machine learning algorithms of two proteins that are linked with AD and exist in the cerebrospinal fluid (CSF). As demonstrated in previous studies, the concentration of the proteins amyloid-β and tau may indicate the existence of AD. The proteins’ concentration in the CSF signifies the condition of AD. The current study can contribute to the existing body of knowledge by enabling the development of a non-invasive diagnostic tool that may help with early diagnosis of AD.

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Apr 2023 • PLOS Computational Biology

Increased A-to-I RNA editing in atherosclerosis and cardiomyopathies

Tomer D Mann, Eli Kopel, Eli Eisenberg, Erez Y Levanon

Adenosine-to-inosine RNA editing is essential to prevent undesired immune activation. This diverse process alters the genetic content of the RNA and may recode proteins, change splice sites and miRNA targets, and mimic genomic mutations. Recent studies have associated or implicated aberrant editing with pathological conditions, including cancer, autoimmune diseases, and neurological and psychiatric conditions. RNA editing patterns in cardiovascular tissues have not been investigated systematically so far, and little is known about its potential role in cardiac diseases. Some hints suggest robust editing in this system, including the fact that ADARB1 (ADAR2), the main coding-sequence editor, is most highly expressed in these tissues. Here we characterized RNA editing in the heart and arteries and examined a contributory role to the development of atherosclerosis and two structural heart diseases -Ischemic and Dilated Cardiomyopathies. Analyzing hundreds of RNA-seq samples taken from the heart and arteries of cardiac patients and controls, we find that global editing, alongside inflammatory gene expression, is increased in patients with atherosclerosis, cardiomyopathies, and heart failure. We describe a single recoding editing site and suggest it as a target for focused research. This recoding editing site in the IGFBP7 gene is one of the only evolutionary conserved sites between mammals, and we found it exhibits consistently increased levels of editing in these patients. Our findings reveal that RNA editing is abundant in arteries and is elevated in several key cardiovascular conditions. They thus provide a roadmap for basic and …

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Apr 2023 • Frontiers in Genome Editing

CRISPR and beyond: Cutting-edge technologies for gene correction in therapeutic applications

Ayal Hendel, Rasmus O Bak

Gene editing promises the ultimate cure for genetic diseases by directly correcting disease-causing variants. However, the first clinical trials have chased the “low hanging fruit” using editing strategies that rely on gene disruption by introducing double-strand DNA breaks that lead to insertions and deletions (indels) by the NHEJ pathway. Since NHEJ is constitutively active throughout the cell cycle and the default DNA repair pathway, this is by far the most efficient type of conventional gene editing as opposed to homology-directed repair (HDR). HDR relies on delivery of an exogenous repair template and this pathway is active only in the S and G2 phases of the cell cycle. These two parameters constitute challenges in clinical use of HDR since exogenous DNA is toxic in most therapeutically relevant cell types and since the inherent competition between NHEJ and HDR can be a bottleneck. However, HDR benefits from enabling precise edits to be made to the genome, thereby representing true gene editing with control over the outcome. Still, in both these modalities the DNA breaks are considered a potential source of genotoxicity due to the possibility of off-target edits and chromosomal aberrations such as translocations and chromothripsis. Next-generation gene editing tools like Base and Prime Editing that rely on DNA single strand nicking reduce the risk of such harmful events but are still limited in the scope of the edits they can generate (Anzalone et al., 2020). The newest types of editors based on CRISPR-associated transposases or CRISPR-directed integrases facilitate larger edits but are still under development and immature for clinical …

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Apr 2023 • Optics Express

Optical sensor for remote estimation of CO2 concentration in the blood stream

Daniel Calili, Yevgeny Biederman, Sergey Agdarov, Yafim Biederman, Zeev Zalevsky

Speckle pattern analysis become a widespread method for remote sensing of various biomedical parameters. This technique is based on tracking the secondary speckle patterns reflected from a human skin illuminated by a laser beam. Speckle pattern variations can be translated into the corresponding partial carbon dioxide (CO 2) state (High or Normal) in the bloodstream. We present a novel approach for remote sensing of human blood carbon dioxide partial pressure (PCO 2) based on speckle pattern analyses combined with machine learning approach. The blood CO 2 partial pressure is an important indicative parameter for a variety of malfunctions in the human body.

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Apr 2023 • Journal of Functional Biomaterials 14 (4), 215, 2023

Proteinoid Polymers and Nanocapsules for Cancer Diagnostics, Therapy and Theranostics: In Vitro and In Vivo Studies

Ella Itzhaki, Yuval Elias, Neta Moskovits, Salomon M Stemmer, Shlomo Margel

Proteinoids—simple polymers composed of amino acids—were suggested decades ago by Fox and coworkers to form spontaneously by heat. These special polymers may self-assemble in micrometer structures called proteinoid microspheres, presented as the protocells of life on earth. Interest in proteinoids increased in recent years, in particular for nano-biomedicine. They were produced by stepwise polymerization of 3–4 amino acids. Proteinoids based on the RGD motif were prepared for targeting tumors. Nanocapsules form by heating proteinoids in an aqueous solution and slowly cooling to room temperature. Proteinoid polymers and nanocapsules suit many biomedical applications owing to their non-toxicity, biocompatibility and immune safety. Drugs and/or imaging reagents for cancer diagnostic, therapeutic and theranostic applications were encapsulated by dissolving them in aqueous proteinoid solutions. Here, recent in vitro and in vivo studies are reviewed.

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