2708 articles

72 publishers

Join mailing list

Sep 2021 • Biophysical Reports

Point-localized, site-specific membrane potential optical recording by single fluorescent nanodiscs

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

Nanodisc technology was implemented as a platform for voltage nanosensors. A fluorescence (Förster) resonance energy transfer (FRET)- based voltage-sensing scheme employing fluorescent nanodiscs and the hydrophobic ion dipicrylamine was developed and utilized to optically record membrane potentials on the single-nanodisc level. Ensemble and single-nanosensor recordings were demonstrated for HEK293 cells and primary cortical neuron cells. Conjugation of nanodiscs to anti-GABAA antibodies allowed for site-specific membrane potential measurements from postsynaptic sites.

Show more

Sep 2021 • Advanced Energy Materials

Fast charging of lithium‐ion batteries: a review of materials aspects

Manuel Weiss, Raffael Ruess, Johannes Kasnatscheew, Yehonatan Levartovsky, Natasha Ronith Levy, Philip Minnmann, Lukas Stolz, Thomas Waldmann, Margret Wohlfahrt‐Mehrens, Doron Aurbach, Martin Winter, Yair Ein‐Eli, Jürgen Janek

Fast charging is considered to be a key requirement for widespread economic success of electric vehicles. Current lithium‐ion batteries (LIBs) offer high energy density enabling sufficient driving range, but take considerably longer to recharge than traditional vehicles. Multiple properties of the applied anode, cathode, and electrolyte materials influence the fast‐charging ability of a battery cell. In this review, the physicochemical basics of different material combinations are considered in detail, identifying the transport of lithium inside the electrodes as the crucial rate‐limiting steps for fast‐charging. Lithium diffusion within the active materials inherently slows down the charging process and causes high overpotentials. In addition, concentration polarization by slow lithium‐ion transport within the electrolyte phase in the porous electrodes also limits the charging rate. Both kinetic effects are responsible for lithium plating …

Show more

Sep 2021 • ChemElectroChem 8 (17), 3229-3238, 2021

Critical Review on the Unique Interactions and Electroanalytical Challenges Related to Cathodes‐Solutions Interfaces in Non‐Aqueous Mg Battery Prototypes

Ran Attias, Daniel Sharon, Yosef Goffer, Doron Aurbach

Rechargeable batteries based on Mg metal anodes may be a promising alternative to current Li‐ion battery systems. However, the development of practical rechargeable Mg batteries (RMBs) is hindered by the absence of cathode materials that can reversibly intercalate Mg ions with a reasonably fast kinetic, while still exhibiting high capacity and high working voltages. In this minireview we summarize our recent progress in understanding cathodes/electrolyte solutions interfaces in non‐aqueous Mg systems. While most studies in the field of cathode materials for RMBs focus on the solid‐state diffusion phenomena of the bare Mg ion within the solid hosts, this minireview summarizes several important findings that demonstrate how the electrochemical response of the cathode material is also significantly influenced by the solution chemistry and structure. We provide a comprehensive description of the sequential …

Show more

Sep 2021 • Molecular Microbiology

Pseudouridines on Trypanosoma brucei mRNAs are developmentally regulated: Implications to mRNA stability and protein binding

K Shanmugha Rajan, Katerina Adler, Hava Madmoni, Dana Peleg‐Chen, Smadar Cohen‐Chalamish, Tirza Doniger, Beathrice Galili, Doron Gerber, Ron Unger, Christian Tschudi, Shulamit Michaeli

The parasite Trypanosoma brucei cycles between an insect and a mammalian host and is the causative agent of sleeping sickness. Here, we performed high‐throughput mapping of pseudouridines (Ψs) on mRNA from two life stages of the parasite. The analysis revealed ~273 Ψs, including developmentally regulated Ψs that are guided by homologs of pseudouridine synthases (PUS1, 3, 5, and 7). Mutating the U that undergoes pseudouridylation in the 3′ UTR of valyl‐tRNA synthetase destabilized the mRNA level. To investigate the mechanism by which Ψ affects the stability of this mRNA, proteins that bind to the 3′ UTR were identified, including the RNA binding protein RBSR1. The binding of RBSR1 protein to the 3′ UTR was stronger when lacking Ψ compared to transcripts carrying the modification, suggesting that Ψ can inhibit the binding of proteins to their target and thus affect the stability of mRNAs …

Show more

Sep 2021 • Physical Review Letters

Weyl Semimetal Path to Valley Filtering in Graphene

Ahmed M Khalifa, Ribhu K Kaul, Efrat Shimshoni, Herbert A Fertig, Ganpathy Murthy

We propose a device in which a sheet of graphene is coupled to a Weyl semimetal, allowing for the physical access to the study of tunneling from two-to three-dimensional massless Dirac fermions. Because of the reconstructed band structure, we find that this device acts as a robust valley filter for electrons in the graphene sheet. We show that, by appropriate alignment, the Weyl semimetal draws away current in one of the two graphene valleys, while allowing current in the other to pass unimpeded. In contrast to other proposed valley filters, the mechanism of our proposed device occurs in the bulk of the graphene sheet, obviating the need for carefully shaped edges or dimensions.

Show more

Sep 2021 • 2021 Fifteenth International Congress on Artificial Materials for Novel Wave …, 2021

Two-Dimensional Solid-State Random Laser

Bhupesh Kumar, Santosh Maurya, Patrick Sebbah

We present random lasing action on a two dimensional (2D) active surface incorporated with randomly distributed air holes: responsible for coherent multiple scattering and couple out the radiation normal to surface.

Show more

Aug 2021 • Physical Review B

Probing the metallic energy spectrum beyond the Thouless energy scale using singular value decomposition

Richard Berkovits

Disordered quantum systems feature an energy scale known as the Thouless energy. For energy ranges below this scale, the properties of the energy spectrum can be described by random matrix theory. Above this scale a different behavior sets in. For a metallic system it was shown long ago by Altshuler and Shklovskii [Sov. Phys. JETP 64, 127 (1986)] that the number variance should increase as a power law with power dependent on only the dimensionality of the system. Although tantalizing hints at this behavior were seen in previous numerical studies, it is quite difficult to verify this prediction using the standard local unfolding methods. Here we use a different unfolding method, ie, singular value decomposition, and establish a connection between the power law behavior of the scree plot (the singular values ranked by their amplitude) and the power law behavior of the number variance. Thus, we are able to …

Show more

Aug 2021 • Nature Communications

A dynamical quantum cheshire cat effect and implications for counterfactual communication

Yakir Aharonov, Eliahu Cohen, Sandu Popescu

Here we report a type of dynamic effect that is at the core of the so called “counterfactual computation” and especially “counterfactual communication” quantum effects that have generated a lot of interest recently. The basic feature of these counterfactual setups is the fact that particles seem to be affected by actions that take place in locations where they never (more precisely, only with infinitesimally small probability) enter. Specifically, the communication/computation takes place without the quantum particles that are supposed to be the information carriers travelling through the communication channel or entering the logic gates of the computer. Here we show that something far more subtle is taking place: It is not necessary for the particle to enter the region where the controlling action takes place; it is enough for the controlled property of the particle,(ie, the property that is being controlled by actions in the control …

Show more

Aug 2021 • Physical Review B

Measurements of polarization dependencies in parametric down-conversion of x rays into ultraviolet radiation

S Sofer, O Sefi, AGA Nisbet, S Shwartz

We present measurements of the polarization dependencies of the x-ray signal photons generated by the effect of parametric down-conversion of x rays into ultraviolet radiation. The results exhibit pronounced discrepancies with the classical model for the nonlinearity but qualitatively agree with a recently developed quantum mechanical theory for the nonlinear interaction. Our work shows that the reconstruction of the atomic scale charge distribution of valence electrons in crystals by using nonlinear interaction between x rays and longer wavelength radiation, as was suggested in previous works, requires the knowledge of polarization of the generated x-ray signal beam. The results presented in this work indicate a methodology for the study of properties of the Wannier functions in crystals.

Show more

Aug 2021 • ChemSusChem

AZ31 Magnesium alloy foils as thin anodes for rechargeable magnesium batteries

Ananya Maddegalla, Ayan Mukherjee, J Alberto Blázquez, Eneko Azaceta, Olatz Leonet, Aroa R Mainar, Aleksey Kovalevsky, Daniel Sharon, Jean-Frédéric Martin, Dane Sotta, Yair Ein-Eli, Doron Aurbach, Malachi Noked

In recent decades, rechargeable Mg batteries (RMBs) technologies have attracted much attention because the use of thin Mg foil anodes may enable development of high‐energy‐density batteries. One of the most critical challenges for RMBs is finding suitable electrolyte solutions that enable efficient and reversible Mg cells operation. Most RMB studies concentrate on the development of novel electrolyte systems, while only few studies have focused on the practical feasibility of using pure metallic Mg as the anode material. Pure Mg metal anodes have been demonstrated to be useful in studying the fundamentals of nonaqueous Mg electrochemistry. However, pure Mg metal may not be suitable for mass production of ultrathin foils (< 100 microns) due to its limited ductility. The metals industry overcomes this problem by using ductile Mg alloys. Herein, the feasibility of processing ultrathin Mg anodes in electrochemical cells was demonstrated by using AZ31 Mg alloys (3% Al; 1% Zn). Thin‐film Mg AZ31 anodes presented reversible Mg dissolution and deposition behavior in complex ethereal Mg electrolytes solutions that was comparable to that of pure Mg foils. Moreover, it was demonstrated that secondary Mg battery prototypes comprising ultrathin AZ31 Mg alloy anodes (≈ 25 μm thick) and Mg x Mo 6 S 8 Chevrel‐phase cathodes exhibited cycling performance equal to that of similar cells containing thicker pure Mg foil anodes. The possibility of using ultrathin processable Mg metal anodes is an important step in the realization of rechargeable Mg batteries.

Show more

Aug 2021 • Advanced Functional Materials 31 (46), 2104887, 2021

Graphene‐Based Nanomaterials for Neuroengineering: Recent Advances and Future Prospective

Raj Kumar, Rossana Rauti, Denis Scaini, Merav Antman‐Passig, Ohad Meshulam, Doron Naveh, Laura Ballerini, Orit Shefi

Graphene unique physicochemical properties made it prominent among other allotropic forms of carbon, in many areas of research and technological applications. Interestingly, in recent years, many studies exploited the use of graphene family nanomaterials (GNMs) for biomedical applications such as drug delivery, diagnostics, bioimaging, and tissue engineering research. GNMs are successfully used for the design of scaffolds for controlled induction of cell differentiation and tissue regeneration. Critically, it is important to identify the more appropriate nano/bio material interface sustaining cells differentiation and tissue regeneration enhancement. Specifically, this review is focussed on graphene‐based scaffolds that endow physiochemical and biological properties suitable for a specific tissue, the nervous system, that links tightly morphological and electrical properties. Different strategies are reviewed to exploit …

Show more

Aug 2021 • The Journal of Physical Chemistry B

Molecular dynamics simulations of the Apo and Holo states of the copper binding protein CueR reveal principal bending and twisting motions

Renana Schwartz, Sharon Ruthstein, Dan Thomas Major

Aug 2021 • Biomacromolecules

Structure and Dynamics Perturbations in Ubiquitin Adsorbed or Entrapped in Silica Materials Are Related to Disparate Surface Chemistries Resolved by Solid-State NMR Spectroscopy

Nurit Adiram-Filiba, Eli Ohaion, Gilit Verner, Avital Schremer, Merav Nadav-Tsubery, Tammy Lublin-Tennenbaum, Keren Keinan-Adamsky, Massimo Lucci, Claudio Luchinat, Enrico Ravera, Gil Goobes

Protein immobilization on material surfaces is emerging as a powerful tool in the design of devices and active materials for biomedical and pharmaceutical applications as well as for catalysis. Preservation of the protein’s biological functionality is crucial to the design process and is dependent on the ability to maintain its structural and dynamical integrity while removed from the natural surroundings. The scientific techniques to validate the structure of immobilized proteins are scarce and usually provide limited information as a result of poor resolution. In this work, we benchmarked the ability of standard solid-state NMR techniques to resolve the effects of binding to dissimilar silica materials on a model protein. In particular, the interactions between ubiquitin and the surfaces of MCM41, SBA15, and silica formed in situ were tested for their influence on the structure and dynamics of the protein. It is shown that the …

Show more

Aug 2021 • Advanced Energy Materials

Bidirectionally Compatible Buffering Layer Enables Highly Stable and Conductive Interface for 4.5 V Sulfide‐Based All‐Solid‐State Lithium Batteries

Longlong Wang, Xingwei Sun, Jun Ma, Bingbing Chen, Chao Li, Jiedong Li, Liang Chang, Xinrun Yu, Ting‐Shan Chan, Zhiwei Hu, Malachi Noked, Guanglei Cui

High‐voltage all‐solid‐state lithium batteries (HVASSLBs) are considered attractive systems for portable electronics and electric vehicles, due to their theoretically high energy density and safety. However, realization of HVASSLBs with sulfide solid electrolytes (SEs) is hindered by their limited electrochemical stability, resulting in sluggish interphase dynamics. Here, a bidirectionally compatible buffering layer design scheme is proposed to overcome the interfacial challenges of sulfide‐based HVASSLBs. As a proof of concept, it is found that NASICON‐type LixZr2(PO4)3 surprisingly exhibit great compatibility with both 4.5 V LiCoO2 and Li6PS5Cl, based on the results of first‐principles calculations and various in situ/ex situ characterizations. This compatibility significantly restrains the interface reactivity and boosts interfacial Li‐ion transport. Therefore, 4.5 V sulfide‐based HVASSLBs can exhibit remarkably …

Show more

Aug 2021 • ACS Applied Energy Materials

Multifold Electrochemical Protons and Zinc Ion Storage Behavior in Copper Vanadate Cathodes

Munseok S Chae, Ran Attias, Ben Dlugatch, Yosef Gofer, Doron Aurbach

Zinc-based batteries are gaining attention as a promising candidate for large-scale energy storage systems due to their safety, abundance of elemental zinc, low cost, and ease of handling in air. However, only a few zinc storage materials, namely, intercalation cathode materials, were reported, and there is a need to develop host structures with improved performance. Here, we investigate copper vanadate as a cathode material and uncover its proton and zinc storage behavior by combined electrochemical characterization, XRD analysis, and ion migration barrier calculations for the cation diffusion pathways. The material showed a highly reversible capacity of ∼315 mA h/g at 20 mA/g with a good capacity retention.

Show more

Aug 2021 • arXiv preprint arXiv:2108.02726

Quantum logical entropy: fundamentals and general properties

Boaz Tamir, Ismael L Paiva, Zohar Schwartzman-Nowik, Eliahu Cohen

Logical entropy gives a measure, in the sense of measure theory, of the distinctions of a given partition of a set, an idea that can be naturally generalized to classical probability distributions. Here, we analyze how fundamental concepts of this entropy and other related definitions can be applied to the study of quantum systems, leading to the introduction of the quantum logical entropy. Moreover, we prove several properties of this entropy for generic density matrices that may be relevant to various areas of quantum mechanics and quantum information. Furthermore, we extend the notion of quantum logical entropy to post-selected systems.

Show more

Aug 2021 • Energies

In Situ Measurement of Localized Current Distribution in H2-Br2 Redox Flow Batteries

Brenda Berenice Martinez Cantu, Peter Fischer, David Zitoun, Jens Tübke, Karsten Pinkwart

Hydrogen bromine redox flow batteries (RFB) are considered to be one of the most promising storage alternatives, as this technology offers both high energy and high-power density. In this work a printed circuit board type of segmented current collector for the measurement of locally resolved current density was developed. This analytical tool was inserted as hydrogen anode current collector in a hydrogen-bromine test cell. Charging and discharging operation was monitored under different stoichiometric flow conditions and the impact on current distribution is presented. This technique offers the possibility to prove cell limiting conditions with spatial resolution, improving our understanding and determining optimal operating conditions for a given design.

Show more

Aug 2021

Picosecond Pulsed Laser Illumination: An Ultimate Solution for Photonic vs. Thermal Processes’ Contest in SOI Photo-Activated Modulator

David Glukhov, Zeev Zalevsky, Avi Karsenty

The functionality of a nanoscale silicon-based optoelectronic modulator is deeply analyzed while it appears that two competing processes, thermal and photonic, are occurring at the same time, and are preventing the optimization of the electro-optics coupling. While an incident illumination-beam first process is translated into photons, generating pairs of electrons-holes, a second process of thermal generation, creating phonons enables a loss of energy. Complementary studies, combining strong analytical models and numerical simulations, enabled to better understand this competition between photonic and thermal activities, in order to optimize the modulator. Moreover, in order to prevent unnecessary heating effects and to present a proposed solution, a picosecond pulsed laser is suggested and demonstrated as the ultimate solution so no energy will be wasted in heat, and still the photonic energy will be fully used. First everanalytical solution to the heating produced due to the laser illumination applied on a nano-photonic device, while the illumination is produced in a periodic time changing function, eg a pulsed illumination, is presented. The present case study and proposed adapted solution can serve as a basis of generic approach in sensors’ activation towards optimized photonics absorption.

Show more

Aug 2021 • Elife

Expanding the MECP2 network using comparative genomics reveals potential therapeutic targets for Rett syndrome

Irene Unterman, Idit Bloch, Simona Cazacu, Gila Kazimirsky, Bruria Ben-Zeev, Benjamin P Berman, Chaya Brodie, Yuval Tabach

Inactivating mutations in the Methyl-CpG Binding Protein 2 (MECP2) gene are the main cause of Rett syndrome (RTT). Despite extensive research into MECP2 function, no treatments for RTT are currently available. Here, we used an evolutionary genomics approach to construct an unbiased MECP2 gene network, using 1028 eukaryotic genomes to prioritize proteins with strong co-evolutionary signatures with MECP2. Focusing on proteins targeted by FDA-approved drugs led to three promising targets, two of which were previously linked to MECP2 function (IRAK, KEAP1) and one that was not (EPOR). The drugs targeting these three proteins (Pacritinib, DMF, and EPO) were able to rescue different phenotypes of MECP2 inactivation in cultured human neural cell types, and appeared to converge on Nuclear Factor Kappa B (NF-kB) signaling in inflammation. This study highlights the potential of comparative genomics to accelerate drug discovery, and yields potential new avenues for the treatment of RTT.

Show more

Aug 2021 • Nanomaterials

Graphene Oxide and Reduced Graphene Oxide Nanoflakes Coated with Glycol Chitosan, Propylene Glycol Alginate, and Polydopamine: Characterization and Cytotoxicity in Human …

Lorenzo Vannozzi, Enrico Catalano, Madina Telkhozhayeva, Eti Teblum, Alina Yarmolenko, Efrat Shawat Avraham, Rajashree Konar, Gilbert Daniel Nessim, Leonardo Ricotti

Recently, graphene and its derivatives have been extensively investigated for their interesting properties in many biomedical fields, including tissue engineering and regenerative medicine. Nonetheless, graphene oxide (GO) and reduced GO (rGO) are still under investigation for improving their dispersibility in aqueous solutions and their safety in different cell types. This work explores the interaction of GO and rGO with different polymeric dispersants, such as glycol chitosan (GC), propylene glycol alginate (PGA), and polydopamine (PDA), and their effects on human chondrocytes. GO was synthesized using Hummer’s method, followed by a sonication-assisted liquid-phase exfoliation (LPE) process, drying, and thermal reduction to obtain rGO. The flakes of GO and rGO exhibited an average lateral size of 8.8±4.6 and 18.3±8.5 µm, respectively. Their dispersibility and colloidal stability were investigated in the presence of the polymeric surfactants, resulting in an improvement in the suspension stability in terms of average size and polydispersity index over 1 h, in particular for PDA. Furthermore, cytotoxic effects induced by coated and uncoated GO and rGO on human chondrocytes at different concentrations (12.5, 25, 50 and 100 µg/mL) were assessed through LDH assay. Results showed a concentration-dependent response, and the presence of PGA contributed to statistically decreasing the difference in the LDH activity with respect to the control. These results open the way to a potentially safer use of these nanomaterials in the fields of cartilage tissue engineering and regenerative medicine. View Full-Text

Show more

Aug 2021 • Journal of Lightwave Technology

Opto-Mechanical Fiber Sensing of Gamma Radiation

Yosef London, Kavita Sharma, Hagai Diamandi, Mirit Hen, Gil Bashan, Elad Zehavi, Shlomi Zilberman, Garry Berkovic, Amnon Zentner, Moshe Mayoni, Andrei A Stolov, Mikhail Kalina, Olga Kleinerman, Ehud Shafir, Avi Zadok

The monitoring of ionizing radiation is critical for the safe operation of nuclear and other high-power plants. Fiber-optic sensing of radiation has been pursued for over 45 years. Most protocols rely on radiation effects on the optical properties of the fiber. Here we propose a new concept, in which the opto-mechanics of standard fibers coated by thin layers of fluoroacrylate polymer are observed instead. The time-of-flight of radial acoustic waves through the coating is evaluated by forward stimulated Brillouin scattering measurements. The time-of-flight is seen to decrease monotonically with the overall dosage of gamma radiation from a cobalt source. Variations reach 15% of the initial value for 180 Mrad dose and remain stable for at least several weeks following exposure. The faster times-of-flight are consistent with a radiation-induced increase in the coating stiffness, observed in offline analysis. The effects on the …

Show more


Powered by Articali