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May 2020 • Entropy

Systems with size and energy polydispersity: from glasses to mosaic crystals

Itay Azizi, Yitzhak Rabin

We use Langevin dynamics simulations to study dense 2d systems of particles with both size and energy polydispersity. We compare two types of bidisperse systems which differ in the correlation between particle size and interaction parameters: in one system big particles have high interaction parameters and small particles have low interaction parameters, while in the other system the situation is reversed. We study the different phases of the two systems and compare them to those of a system with size but not energy bidispersity. We show that, depending on the strength of interaction between big and small particles, cooling to low temperatures yields either homogeneous glasses or mosaic crystals. We find that systems with low mixing interaction, undergo partial freezing of one of the components at intermediate temperatures, and that while this phenomenon is energy-driven in both size and energy bidisperse systems, it is controlled by entropic effects in systems with size bidispersity only. View Full-Text

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May 2020 • Micromachines

Patterning of particles and live cells at single cell resolution

Adar Hacohen, Hadass R Jessel, Alon Richter-Levin, Orit Shefi

The ability to manipulate and selectively position cells into patterns or distinct microenvironments is an important component of many single cell experimental methods and biological engineering applications. Although a variety of particles and cell patterning methods have been demonstrated, most of them deal with the patterning of cell populations, and are either not suitable or difficult to implement for the patterning of single cells. Here, we describe a bottom-up strategy for the micropatterning of cells and cell-sized particles. We have configured a micromanipulator system, in which a pneumatic microinjector is coupled to a holding pipette capable of physically isolating single particles and cells from different types, and positioning them with high accuracy in a predefined position, with a resolution smaller than 10 µm. Complementary DNA sequences were used to stabilize and hold the patterns together. The system is accurate, flexible, and easy-to-use, and can be automated for larger-scale tasks. Importantly, it maintains the viability of live cells. We provide quantitative measurements of the process and offer a file format for such assemblies. View Full-Text

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May 2020 • Iscience

Solid-state protein junctions: cross-laboratory study shows preservation of mechanism at varying electronic coupling

Sabyasachi Mukhopadhyay, Senthil Kumar Karuppannan, Cunlan Guo, Jerry A Fereiro, Adam Bergren, Vineetha Mukundan, Xinkai Qiu, Olga E Castañeda Ocampo, Xiaoping Chen, Ryan C Chiechi, Richard McCreery, Israel Pecht, Mordechai Sheves, Rupali Reddy Pasula, Sierin Lim, Christian A Nijhuis, Ayelet Vilan, David Cahen

Successful integration of proteins in solid-state electronics requires contacting them in a non-invasive fashion, with a solid conducting surface for immobilization as one such contact. The contacts can affect and even dominate the measured electronic transport. Often substrates, substrate treatments, protein immobilization, and device geometries differ between laboratories. Thus the question arises how far results from different laboratories and platforms are comparable and how to distinguish genuine protein electronic transport properties from platform-induced ones. We report a systematic comparison of electronic transport measurements between different laboratories, using all commonly used large-area schemes to contact a set of three proteins of largely different types. Altogether we study eight different combinations of molecular junction configurations, designed so that Ageoof junctions varies from 105 to 10−3 …

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May 2020 • CLEO: Science and Innovations, SM2J. 5, 2020

Surface-acoustic-wave modulation of a silicon-on-insulator defect Bragg grating

Dvir Munk, Moshe Katzman, Mint Hen, Maayan Priel, Avi Zadok

A surface acoustic wave modulator is implemented in standard silicon-on-insulator. Acoustic waves are stimulated by absorption of pump light in metallic patterns and thermo-elastic expansion, and modulate probe light in a defect waveguide grating cavity.

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May 2020 • The Israel Medical Association journal: IMAJ

Prevention and treatment of Pseudomonas aeruginosa-based biofilm with ethanol

Michal Natan, Gila Jacobi, Ehud Banin, Shai Ashkenazi

BackgroundAlthough indwelling catheters are increasingly used in modern medicine, they can be a source of microbial contamination and hard-to-treat biofilms, which jeopardize patient lives. At times 70% ethanol is used as a catheter-lock solution due to its bactericidal properties. However, high concentrations of ethanol can result in adverse effects and in malfunction of the catheters.ObjectivesTo determine whether low concentrations of ethanol can prevent and treat biofilms of Pseudomonas aeruginosa.MethodsEthanol was tested at a concentration range of 0.625-80% against laboratory and clinical isolates of P. aeruginosa for various time periods (2-48 hours). The following parameters were evaluated following ethanol exposure: prevention of biofilm formation, reduction of biofilm metabolic activity, and inhibition of biofilm regrowth.ResultsExposing P. aeruginosa to twofold ethanol gradients demonstrated a …

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May 2020 • Optics letters

Subattosecond x-ray Hong–Ou–Mandel metrology

Sergey Volkovich, Sharon Shwartz

We show that subattosecond delays and subangstrom optical path differences can be measured by using Hong–Ou–Mandel interference measurements with x-rays. Our scheme relies on the subattosecond correlation time of photon pairs that are generated by x-ray spontaneous parametric down-conversion, which leads to a dip in correlation measurements with a comparable width. Therefore, the precision of the measurements is expected to be better than 0.1 attosecond. We anticipate that the scheme we describe in this work will lead to the development of various techniques of quantum measurements with ultra-high precision at x-ray wavelengths.

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May 2020 • Macromolecules

Aging of thermoreversible gel of associating polymers

Kulveer Singh, Yitzhak Rabin

We performed Langevin dynamics simulations of amphiphilic polymers that contain strongly associating stickers connected by long soluble chain segments. We explored the aging of a thermoreversible gel, which is cross-linked by aggregates (clusters) of the stickers, and observed a dramatic increase of their lifetime with aging. We find that the observed aging is the result of structural reorganization of the network: the number of cross-links decreases with time as small clusters disintegrate and their stickers are reabsorbed by large clusters that grow and become more stable by forming additional intramolecular associations between their stickers.

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May 2020 • CLEO: Science and Innovations, STh1R. 3, 2020

Surface-acoustic-wave characterization of thin layer deposition on a standard silicon-photonic circuit

Mirit Hen, Dvir Munk, Moshe Katzman, Maayan Priel, Sarah Taragin, Avi Zadok

A thin layer of alumina is characterized using a surface acoustic wave photonic circuit in standard silicon on insulator. Small changes in acoustic velocity are identified by an integrated microwave photonic filter, through acoustic delays.

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May 2020 • CLEO: Applications and Technology, ATh3K. 4, 2020

Speckle Based Sensing using Incoherent Thermal Light Source: Passive Speckles

Hadar Genish, Lauren Wolbromsky, Matan Benyamin, Ran Califa, Zeev Zalevsky

The angle of a rotating diffuser was evaluated by tracking the speckle pattern produced from an incoherent thermal radiation source demonstrating the use of an incoherent source for speckle-based sensing.

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May 2020 • ANESTHESIA AND ANALGESIA 130, 468-470, 2020

Ketamine Impairs Neural Cell Functions by Altering the BDNF Pathway and Glial Cell Polarization

Donald H Penning, Simona Cazacu, Cunli Xiang, Chaya Brodie

May 2020 • arXiv preprint arXiv:2005.12079

Correlation Minor Norm as a Detector and Quantifier of Entanglement

Bar Y Peled, Amit Te'eni, Avishy Carmi, Eliahu Cohen

In this paper we develop an approach for detecting entanglement, which is based on measuring quantum correlations and constructing a correlation matrix. The correlation matrix is then used for defining a family of parameters, named Correlation Minor Norms, which allow one to detect entanglement. This approach generalizes the computable cross-norm or realignment (CCNR) criterion, and moreover requires measuring a state-independent set of operators. Furthermore, we illustrate a scheme which yields for each Correlation Minor Norm a separable state that maximizes it. The proposed entanglement detection scheme is believed to be advantageous in comparison to other methods because correlations have a simple, intuitive meaning and in addition they can be directly measured in experiment. Moreover, it is demonstrated to be stronger than the CCNR criterion. We also illustrate the relation between the …

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May 2020 • CLEO: QELS_Fundamental Science, FM2P. 4, 2020

Exceptional points in fiber optomechanics

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

We report the first realization of an anti-parity-time symmehic optical potential supporting a 2 nd-order exceptional point in standard optical fibers. Phase-transition, symmehy-breaking and coalescence of supeimodes are observed when Brillouin optomechanical coupling exceeds the wavenumber-mismatch.

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May 2020 • arXiv e-prints

Direct observation and simulation of the diffractive saturable loss mechanism in a Kerr-lens mode-locked laser

Idan Parshani, Leon Bello, Mallachi-Elia Meller, Avi Pe'er

Passive mode-locking critically relies on a saturable loss mechanism to form ultrashort pulses. However, in Kerr-lens mode-locking (KLM), no actual absorption takes place, but rather losses appear due to diffraction, and actual light must escape the cavity. The Kerr-lens effect works to generate through diffraction an effective instantaneous saturable absorber that delicately depends on the interplay between the spatial and temporal profiles of the pulse. Despite the importance of KLM as a technique for generating ultrafast pulses and the fundamental role of the diffraction losses in its operation, these losses were never directly observed. Here, we measure the light that leaks out due to diffraction losses in a Kerr-lens mode-locked Ti: Sapphire laser, and compare the measured results with a numerical theory that explicitly calculates the spatio-temporal behavior of the pulse.

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May 2020 • CLEO: Applications and Technology, AF3K. 6, 2020

Design and fundamental limits of nearfield magnetic-force scanning microscopy via the no-cloning theorem

Jonathan Nemirovsky, Chen Mechel, Eliahu Cohen, Ido Kaminer

We analyze nearfield measurements of magnetic fields originating from quantum sources and measured by quantum probes. We show that cloning-inspired techniques reveal optimal measurement schemes and new universal precision bounds for nearfield detectors.

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May 2020 • Applied optics

Superresolved space-dependent sensing of temporal signals by space multiplexing

Gal Chen, Sagie Asraf, Zeev Zalevsky

In this paper we present a novel, to the best of our knowledge, superresolved sensing concept aiming to improve the resolution of temporal signals obtained by applying space multiplexing. The system’s temporal resolution is limited due to the sensor’s time averaging. The proposed superresolution technique overcomes this time average and can therefore increase the system’s temporal resolution. In addition, we also show how to increase the temporal sampling rate, which also affects the temporal resolution. The proposed concept requires that the object will be fixed in space in order to apply the space multiplexing. It can especially be relevant for superresolving laser-based time-of-flight sensors and images as well as light detection and ranging (lidar) devices.

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May 2020 • ECS Meeting Abstracts

The Relationship of Morphology and Catalytic Activity: A Case Study of Iron Corrole Incorporated in High Surface Area Carbon Supports

Lior Elbaz, Naomi Levy

In the past several years we have been thoroughly studying the performance of molecular catalysts for oxygen reduction based on metallo-corrole. We studied the effect of the metal center, substituents in their meso and beta positions and ORR mechanism at a wide pH range. The most influential factor was found to be the metal center while the effect of electro-negative substituents seems to diminish once these molecular catalysts were incorporated in porous carbon supports. Moreover, the overall activity and reaction selectivity has increased dramatically after this incorporation, and was found to be dependent on the carbon support. Specifically, metallo-corroles have shown to have unique catalytic properties for oxygen reduction when adsorbed on a high surface area carbon: BP2000. The nature of the interaction between carbon surfaces and metallo-corroles was identified in this work. The results suggests that …

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Apr 2020 • Review of Scientific Instruments

Harmonic height distribution in pickup spectroscopy within electrostatic ion beam traps

Michal Kahana, Lihi Musbat, Maria Nihamkin, Yael Diamant, Silvia Piperno, Shany Ytzhak, Yoni Toker

Pickup spectroscopy is a means of determining the abundance, mass, charge, and lifetime of ions oscillating in electrostatic ion beam traps. Here, we present a framework for describing the harmonic height distribution of the Fourier transform of the pickup signal and discuss the importance of the pickup positioning, bunch dynamics, and pickup width on the harmonic height distribution. We demonstrate the methodology using measurements from a newly constructed electrostatic ion beam trap.

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Apr 2020 • Mediators of Inflammation

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Hande Erman, Engin Beydogan, Seher Irem Cetin, Banu Boyuk

Background. Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases, which has recently been mentioned as an independent cardiovascular risk factor. Objectives. Endocan is a novel molecule of endothelial dysfunction. We aimed to evaluate the associations of serum endocan levels with the hepatic steatosis index (HSI), fatty liver index (FLI), and degrees of hepatosteatosis in patients with metabolic syndrome with NAFLD. Design and Setting. This cross-sectional prospective study was performed in the outpatient clinic of an internal medicine department. Methods. The study included 40 patients with metabolic syndrome with NAFLD as noted using hepatic ultrasound and 20 healthy controls. Secondary causes of fatty liver were excluded. FLI and HSI calculations were recorded. Serum endocan level values were obtained after overnight fasting. Results. Higher values of HSI and …

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Apr 2020 • Optical Tomography and Spectroscopy, SM3D. 1, 2020

Photonic non-contact tomographic & volumetric tissue probing

Ariel Schwarz, Nisan Ozana, Amir Semer, Ran Califa, Hadar Genish, Zeev Zalevsky

We present speckle and Michelson interference based photonic technique for performing depth measurement and elastography of a tissue. Photons from different depths of the tissue are separated by analyzing the flickering frequencies of collected speckles.

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Apr 2020 • Scientific reports

Author Correction: Non-Invasive Imaging Through Scattering Medium by Using a Reverse Response Wavefront Shaping Technique

Abhijit Sanjeev, Yuval Kapellner, Nadav Shabairou, Eran Gur, Moshe Sinvani, Zeev Zalevsky

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author (s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons. org/licenses/by/4.0/.

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Apr 2020 • Clinical and Translational Biophotonics, TW4B. 5, 2020

Monitoring of vital bio-signs by multimode speckle based optical fiber sensor

Aviya Bennett, Yevgeny Beiderman, Sergey Agdarov, Yafim Beiderman, Rotem Hendel, Barak Straussman, Zeev Zalevsky

We present development and experimental validation of the multimode fiber sensor for monitoring of vital bio signs. The goal is to advance a simple, clothes embedded sensor to monitor the condition of the cardiovascular system.

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