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Jan 2021 • International journal of molecular sciences

Weak Electromagnetic Fields Accelerate Fusion of Myoblasts

Dana Adler, Zehavit Shapira, Shimon Weiss, Asher Shainberg, Abram Katz

Weak electromagnetic fields (WEF) alter Ca 2+ handling in skeletal muscle myotubes. Owing to the involvement of Ca 2+ in muscle development, we investigated whether WEF affects fusion of myoblasts in culture. Rat primary myoblast cultures were exposed to WEF (1.75 µT, 16 Hz) for up to six days. Under control conditions, cell fusion and creatine kinase (CK) activity increased in parallel and peaked at 4–6 days. WEF enhanced the extent of fusion after one and two days (by~ 40%) vs. control, but not thereafter. Exposure to WEF also enhanced CK activity after two days (almost four-fold), but not afterwards. Incorporation of 3 H-thymidine into DNA was enhanced by one-day exposure to WEF (~ 40%), indicating increased cell replication. Using the potentiometric fluorescent dye di-8-ANEPPS, we found that exposure of cells to 150 mM KCl resulted in depolarization of the cell membrane. However, prior exposure of cells to WEF for one day followed by addition of KCl resulted in hyperpolarization of the cell membrane. Acute exposure of cells to WEF also resulted in hyperpolarization of the cell membrane. Twenty-four hour incubation of myoblasts with gambogic acid, an inhibitor of the inward rectifying K+ channel 2.1 (K ir 2.1), did not affect cell fusion, WEF-mediated acceleration of fusion or hyperpolarization. These data demonstrate that WEF accelerates fusion of myoblasts, resulting in myotube formation. The WEF effect is associated with hyperpolarization but WEF does not appear to mediate its effects on fusion by activating K ir 2.1 channels. View Full-Text

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Jan 2021 • bioRxiv

Multi-parameter photon-by-photon hidden Markov modeling

Paul David Harris, Shimon Weiss, Eitan Lerner

Single molecule FRET (smFRET) is a useful tool for studying biomolecular sub-populations and their dynamics. Advanced smFRET-based techniques often track multiple parameters simultaneously, increasing the information content of the measurement. Photon-by-photon hidden Markov modelling (H2MM) is a smFRET analysis tool that quantifies FRET dynamics of single biomolecules, even if they occur in sub-milliseconds. However, sub-populations can be characterized by additional experimentally-derived parameters other than the FRET efficiency. We introduce multiparameter H2MM (mpH2MM) that identifies sub-populations and their transition dynamics based on multiple experimentally-derived parameters, simultaneously. We show the use of this tool in deciphering the number of underlying sub-populations, their mean characteristics and the rate constants of their transitions for a DNA hairpin exhibiting milliseconds FRET dynamics, and for the RNA polymerase promoter open complex exhibiting sub-millisecond FRET dynamics of the transcription bubble. Overall, we show that using mpH2MM facilitates the identification and quantification of biomolecular sub-populations in smFRET measurements that are otherwise difficult to identify. Finally we provide the means to use mpH2MM in analyzing FRET dynamics in advanced multi-color smFRET-based measurements.

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Jan 2021 • bioRxiv

In vitro and in vivo NIR Fluorescence Lifetime Imaging with a time-gated SPAD camera

Jason T Smith, Alena Rudkouskaya, Shan Gao, Juhi M Gupta, Arin Ulku, Claudio Bruschini, Edoardo Charbon, Shimon Weiss, Margarida Barroso, Xavier Intes, Xavier Michalet

Near-infrared (NIR) fluorescence lifetime imaging (FLI) provides a unique contrast mechanism to monitor biological parameters and molecular events in vivo. Single-photon avalanche photodiode (SPAD) cameras have been recently demonstrated in FLI microscopy (FLIM) applications, but their suitability for in vivo macroscopic FLI (MFLI) in deep tissues remains to be demonstrated. Herein, we report in vivo NIR MFLI measurement with SwissSPAD2, a large time-gated SPAD camera. We first benchmark its performance in well-controlled in vitro experiments, ranging from monitoring environmental effects on fluorescence lifetime, to quantifying Förster Resonant Energy Transfer (FRET) between dyes. Next, we use it for in vivo studies of target-drug engagement in live and intact tumor xenografts using FRET. Information obtained with SwissSPAD2 was successfully compared to that obtained with a gated-ICCD camera, using two different approaches. Our results demonstrate that SPAD cameras offer a powerful technology for in vivo preclinical applications in the NIR window.

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Jan 2021 • Metamaterials, Metadevices, and Metasystems 2021, 2021

Subwavelength Mie-resonant selenium resonators for mid-infrared meta-optics

Danveer Singh, Tomer Lewi

Efficient light manipulation at subwavelength scales in the mid-infrared (MIR) region is essential for various applications and can be harnessed from intrinsic low-loss dielectric resonators. Here, we demonstrate the fabrication of truncated spherical selenium (Se) resonators with tunable high-quality (Q) factor Mie resonances. Large area amorphous Se subwavelength resonators of varying sizes were grown on different substrates, using a novel CVD process. We demonstrate size-tunable Mie resonances spanning the 2-16 µm range, for single isolated resonators and large area ensembles, respectively. We show strong tunable absorption resonances (90%) in ensembles of resonators in a significantly broad MIR range. Moreover, by coupling resonators to epsilon-near-zero (ENZ) substrates, we engineer high-Q resonances as high as Q=40. These findings open up new possibilities in meta-atom paints, anti …

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Jan 2021 • Sensors

Rapid and Sensitive Inhibitor Screening Using Magnetically Modulated Biosensors

Shira Roth, Amos Danielli

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

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Jan 2021 • Zika Virus Impact, Diagnosis, Control, and Models, 231-241, 2021

Magnetic modulation biosensing: How it works and how it can be used to detect the Zika virus

Shira Roth, Amos Danielli

Current serological diagnostic tests for Zika virus (ZIKV) suffer from reduced sensitivity, high cross-reactivity, low specificity, and lengthy protocols. Here, we begin by reviewing serological and antigenemia assays that are either commercially available or under development. We then focus on a new technology, named magnetic modulation biosensing (MMB), that enables rapid detection of ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. The MMB system utilizes magnetic beads that are conjugated to recombinant ZIKV nonstructural 1 (NS1) protein, which specifically captures Zika IgM/IgG antibodies. A second fluorescently labeled antibody is then added, forming a “sandwich” with the analyte and the capture protein. An oscillating magnetic field gradient concentrates the beads within the sample volume and transports them in a periodic motion in and out of a laser beam, producing an …

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Jan 2021 • Nano Energy

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

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

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

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Jan 2021 • PLoS computational biology

Breast cancer is marked by specific, Public T-cell receptor CDR3 regions shared by mice and humans

Miri Gordin, Hagit Philip, Alona Zilberberg, Moriah Gidoni, Raanan Margalit, Christopher Clouser, Kristofor Adams, Francois Vigneault, Irun R Cohen, Gur Yaari, Sol Efroni

The partial success of tumor immunotherapy induced by checkpoint blockade, which is not antigen-specific, suggests that the immune system of some patients contain antigen receptors able to specifically identify tumor cells. Here we focused on T-cell receptor (TCR) repertoires associated with spontaneous breast cancer. We studied the alpha and beta chain CDR3 domains of TCR repertoires of CD4 T cells using deep sequencing of cell populations in mice and applied the results to published TCR sequence data obtained from human patients. We screened peripheral blood T cells obtained monthly from individual mice spontaneously developing breast tumors by 5 months. We then looked at identical TCR sequences in published human studies; we used TCGA data from tumors and healthy tissues of 1,256 breast cancer resections and from 4 focused studies including sequences from tumors, lymph nodes, blood and healthy tissues, and from single cell dataset of 3 breast cancer subjects. We now report that mice spontaneously developing breast cancer manifest shared, Public CDR3 regions in both their alpha and beta and that a significant number of women with early breast cancer manifest identical CDR3 sequences. These findings suggest that the development of breast cancer is associated, across species, with biomarker, exclusive TCR repertoires.

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Jan 2021 • Batteries & Supercaps

Enhancement of Structural, Electrochemical, and Thermal Properties of Ni‐Rich LiNi0.85Co0.1Mn0.05O2 Cathode Materials for Li‐Ion Batteries by Al and Ti …

Yehonatan Levartovsky, Xiaohan Wu, Christoph Erk, Sandipan Maiti, Judith Grinblat, Michael Talianker, Doron Aurbach

Ni‐rich layered oxides LiNi1‐x‐yCoxMnyO2 (1−x−y>0.5) are promising cathode materials for the new generation of Li‐ion batteries suitable for electro‐mobility due to their high energy density, good rate capability, and relatively low cost. However, their main drawback is poor cycling performance, particularly at elevated temperatures. In this research, it is demonstrated how doping with Al and Ti, using straightforward solid‐state mixing synthesis, can dramatically enhance the structural, electrochemical, and thermal properties of LiNi0.85Co0.1Mn0.05O2 (NCM85). The capacity retention of Al‐doped and Ti‐doped cathodes after 100 cycles at 100 % DOD at 1 C and 45 °C using standard electrolyte solutions could reach nearly 99 % and 78 %, respectively, while the capacity retention of the undoped material was less than 74 % in similar experiments. Doping with Al and Ti facilitates the Li intercalation …

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Jan 2021 • Nature Communications

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

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

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

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Jan 2021 • Materials Today

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

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

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

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Jan 2021 • Science

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

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

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

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Jan 2021 • Nontraditional Activation Methods in Green and Sustainable Applications, 171-239, 2021

The catalytic production of biofuels (biodiesel and bioethanol) using sonochemical, microwave, and mechanical methods

Indra Neel Pulidindi, Aharon Gedanken

The advent of microwave technology and its application to transesterification reaction has revolutionized the biodiesel production process. Unambiguously the microwave-activated solid base catalyzed process is recommended for industrial adaptation. Several solid base catalysts were developed among which SrO-based catalyst supported on millimetric silica beads and SrO supported on porous titanium matrix stand out. Sonochemical methods of activation have the potential for acceleration of biodiesel production. However, the use of homogenization reactor outperformed sonication technology for large-scale utility of biodiesel production. Use of activation methods like microfluidic reactor and solar energy for biodiesel production should not be neglected and should be developed on a par with microwave technology. State-of-the-art methods developed for the production of biodiesel using nontraditional methods …

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Jan 2021 • Nanomaterials

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

Gil Otis, Michal Ejgenberg, Yitzhak Mastai

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

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Jan 2021 • bioRxiv

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

Pavel Janoš, Jana Aupič, Sharon Ruthstein, Alessandra Magistrato

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

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Jan 2021 • bioRxiv

immuneML: an ecosystem for machine learning analysis of adaptive immune receptor repertoires

Milena Pavlovic, Lonneke Scheffer, Keshav Motwani, Chakravarthi Kanduri, Radmila Kompova, Nikolay Vazov, Knut Waagan, Fabian LM Bernal, Alexandre Almeida Costa, Brian Corrie, Rahmad Akbar, Ghadi S Al Hajj, Gabriel Balaban, Todd M Brusko, Maria Chernigovskaya, Scott Christley, Lindsay G Cowell, Robert Frank, Ivar Grytten, Sveinung Gundersen, Ingrid Hobæk Haff, Sepp Hochreiter, Eivind Hovig, Ping-Han Hsieh, Gunter Klambauer, Marieke L Kuijjer, Christin Lund-Andersen, Antonio Martini, Thomas Minotto, Johan Pensar, Knut Rand, Enrico Riccardi, Philippe A Robert, Artur Rocha, Andrei Slabodkin, Igor Snapkov, Ludvig M Sollid, Dmytro Titov, Cédric R Weber, Michael Widrich, Gur Yaari, Victor Greiff, Geir Kjetil Sandve

Adaptive immune receptor repertoires (AIRR) are key targets for biomedical research as they record past and ongoing adaptive immune responses. The capacity of machine learning (ML) to identify complex discriminative sequence patterns renders it an ideal approach for AIRR-based diagnostic and therapeutic discovery. To date, widespread adoption of AIRR ML has been inhibited by a lack of reproducibility, transparency, and interoperability. immuneML ( addresses these concerns by implementing each step of the AIRR ML process in an extensible, open-source software ecosystem that is based on fully specified and shareable workflows. To facilitate widespread user adoption, immuneML is available as a command-line tool and through an intuitive Galaxy web interface, and extensive documentation of workflows is provided. We demonstrate the broad applicability of immuneML by (i) reproducing a large-scale study on immune state prediction, (ii) developing, integrating, and applying a novel method for antigen specificity prediction, and (iii) showcasing streamlined interpretability-focused benchmarking of AIRR ML.

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Jan 2021 • Advanced Materials

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

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

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

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Jan 2021 • Materials

Wear Behavior Characterization of Hydrogels Constructs for Cartilage Tissue Replacement

Saverio Affatato, Diego Trucco, Paola Taddei, Lorenzo Vannozzi, Leonardo Ricotti, Gilbert Daniel Nessim, Gina Lisignoli

This paper aims to characterize the wear behavior of hydrogel constructs designed for human articular cartilage replacement. To this purpose, poly (ethylene glycol) diacrylate (PEGDA) 10% w/v and gellan gum (GG) 1.5% w/v were used to reproduce the superior (SUP) cartilage layer and PEGDA 15% w/v and GG 1.5% w/v were used to reproduce the deep (DEEP) cartilage layer, with or without graphene oxide (GO). These materials (SUP and DEEP) were analyzed alone and in combination to mimic the zonal architecture of human articular cartilage. The developed constructs were tested using a four-station displacement control knee joint simulator under bovine calf serum. Roughness and micro-computer tomography (µ-CT) measurements evidenced that the hydrogels with 10% w/v of PEGDA showed a worse behavior both in terms of roughness increase and loss of uniformly distributed density than 15% w/v of PEGDA. The simultaneous presence of GO and 15% w/v PEGDA contributed to keeping the hydrogel construct’s characteristics. The Raman spectra of the control samples showed the presence of unreacted C= C bonds in all the hydrogels. The degree of crosslinking increased along the series SUP&lt; DEEP+ SUP&lt; DEEP without GO. The Raman spectra of the tested hydrogels showed the loss of diacrylate groups in all the samples, due to the washout of unreacted PEGDA in bovine calf serum aqueous environment. The loss decreased along the series SUP&gt; DEEP+ SUP&gt; DEEP, further confirming that the degree of photo-crosslinking of the starting materials plays a key role in determining their wear behavior. μ-CT and Raman …

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Jan 2021 • bioRxiv

Optical probing of local membrane potential with fluorescent polystyrene beads

Zehavit Shapira, Nurit Degani-Katzav, Shimon Yudovich, Asaf Grupi, Shimon Weiss

Studying the electrical activity in single cells and in local circuits of excitable cells, like neurons, requires an easy to use and high throughput methodology that enables the measurement of membrane potential. Studying the electrical properties in particular sub-compartments of neurons, or in a specific type of neurons produces additional complexity. An optical voltage-imaging technique that allows high spatial and temporal resolution could be an ideal solution. However, most of the valid voltage imaging techniques are nonspecific; The ones that are more site-directed require much pre-work and specific adaptations in addition to other disadvantages. Here, a new technique for membrane voltage imaging, based on FRET between fluorescent polystyrene (FPS) beads and Dipicrylamine (DPA) is explored. Not only fluorescent intensity is demonstrated to be correlated with membrane potential, but more importantly, single particle voltage detection is demonstrated. Among other advantages, FPS beads can be synthesized with functional surface groups, and be further targeted to specific proteins via conjugation of recognition molecules. Therefore, FPS beads, in the presence of DPA, constitute single-particle detectors for membrane voltage, with a potential to be localized to specific membrane compartments. This new and accessible platform for targeted optical voltage imaging may further elucidate the mechanisms of neuronal electrical activity.

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Jan 2021 • Applied Sciences

Knowledge of Quantum Hidden Variables Enables Backwards-In-Time Signaling

Avishy Carmi, Eliahu Cohen, Lorenzo Maccone, Hrvoje Nikolić

Bell’s theorem implies that any completion of quantum mechanics which uses hidden variables (that is, preexisting values of all observables) must be nonlocal in the Einstein sense. This customarily indicates that knowledge of the hidden variables would permit superluminal communication. Such superluminal signaling, akin to the existence of a preferred reference frame, is to be expected. However, here we provide a protocol that allows an observer with knowledge of the hidden variables to communicate with her own causal past, without superluminal signaling. That is, such knowledge would contradict causality, irrespectively of the validity of relativity theory. Among the ways we propose for bypassing the paradox there is the possibility of hidden variables that change their values even when the state does not, and that means that signaling backwards in time is prohibited in Bohmian mechanics. View Full-Text

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Jan 2021 • Applied Sciences

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

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

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

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