Feb 2021 • Current Biology
Assa Bentzur, Shir Ben-Shaanan, Jennifer IC Benichou, Eliezer Costi, Mali Levi, Amiyaal Ilany, Galit Shohat-Ophir
Living in a group creates a complex and dynamic environment in which behavior of individuals is influenced by and affects the behavior of others. Although social interaction and group living are fundamental adaptations exhibited by many organisms, little is known about how prior social experience, internal states, and group composition shape behavior in groups. Here, we present an analytical framework for studying the interplay between social experience and group interaction in Drosophila melanogaster. We simplified the complexity of interactions in a group using a series of experiments in which we controlled the social experience and motivational states of individuals to compare behavioral patterns and social networks of groups under different conditions. We show that social enrichment promotes the formation of distinct group structure that is characterized by high network modularity, high inter-individual and …
Show moreFeb 2021 • Biosensors and Bioelectronics
Yujia Lv, Dawei Liang, Shanfu Lu, Doron Aurbach, Yan Xiang
Hampered by the absence of evidence and theoretical model of biological semiconductors, the unidirectional electron transport via the p-n junction between functional proteins and abiotic materials remains a challenge for bioelectronics. Bacteriorhodopsin (bR), a representative transmembrane protein, has demonstrated exceptional optoelectronic effects in bR/semiconductor hybrid materials and offers a possible pathway for addressing this challenge. In the present work, for the first time, bR is proved to be an n-type semiconductor with an indirect electron transition. Through the photo-electrochemical method used for studying the p-n junction effect in the bR and p-type semiconductor combined electrodes, we reached several important conclusions: The self-corrosion of bR integrated Cu2O electrodes is delayed for about 36 times; The photocurrent of bR integrated CuSCN electrodes is enhanced by about 400 …
Show moreFeb 2021 • Viruses
Esther Shmidov, Itzhak Zander, Ilana Lebenthal-Loinger, Sarit Karako-Lampert, Sivan Shoshani, Ehud Banin
Prophages are bacteriophages in the lysogenic state, where the viral genome is inserted within the bacterial chromosome. They contribute to strain genetic variability and can influence bacterial phenotypes. Prophages are highly abundant among the strains of the opportunistic pathogen Pseudomonas aeruginosa and were shown to confer specific traits that can promote strain pathogenicity. The main difficulty of studying those regions is the lack of a simple prophage-curing method for P. aeruginosa strains. In this study, we developed a novel, targeted-curing approach for prophages in P. aeruginosa. In the first step, we tagged the prophage for curing with an ampicillin resistance cassette (ampR) and further used this strain for the sacB counter-selection marker’s temporal insertion into the prophage region. The sucrose counter-selection resulted in different variants when the prophage-cured mutant is the sole variant that lost the ampR cassette. Next, we validated the targeted-curing with local PCR amplification and Whole Genome Sequencing. The application of the strategy resulted in high efficiency both for curing the Pf4 prophage of the laboratory wild-type (WT) strain PAO1 and for PR2 prophage from the clinical, hard to genetically manipulate, 39016 strain. We believe this method can support the research and growing interest in prophage biology in P. aeruginosa as well as additional Gram-negative bacteria.
Show moreFeb 2021 • Journal of Applied Toxicology
Alessia Bertero, Graziano Colombo, Cristina Cortinovis, Virginia Bassi, Elisa Moschini, Nicholas Bellitto, Maria Chiara Perego, Marco Albonico, Emanuela Astori, Isabella Dalle‐Donne, Aharon Gedanken, Ilana Perelshtein, Paride Mantecca, Francesca Caloni
Feb 2021 • Physical Review Letters
Leon Bello, Marcello Calvanese Strinati, Shai Ben-Ami, Avi Pe’er
Mode locking in lasers is a collective effect, where due to a weak coupling a large number of frequency modes lock their phases to oscillate in unison, forming an ultrashort pulse in time. We demonstrate an analogous collective effect in coupled parametric oscillators, which we term “pairwise mode locking,” where many pairs of modes with twin frequencies (symmetric around the center carrier) oscillate simultaneously with a locked phase sum, while the phases of individual modes remain undefined. Thus, despite being broadband and multimode, the emission is not pulsed and lacks first-order coherence, while possessing a very high degree of second-order coherence. Our configuration comprises two coupled parametric oscillators within identical multimode cavities, where the coupling between the oscillators is modulated in time at the repetition rate of the cavity modes, with some analogy to active mode locking in …
Show moreFeb 2021 • Optics Express
Zeev Kalyuzhner, Sergey Agdarov, Aviya Bennett, Yafim Beiderman, Zeev Zalevsky
Speckle pattern analysis has been found by many researchers to be applicable to remote sensing of various biomedical parameters. This paper shows how analysis of dynamic differential speckle patterns scattered from subjects’ sclera illuminated by a laser beam allows extraction of micro-saccades movement in the human eye. Analysis of micro-saccades movement using advanced machine learning techniques based on convolutional neural networks offers a novel approach for non-contact assessment of human blood oxygen saturation level (SpO2). Early stages of hypoxia can rapidly progress into pneumonia and death, and lives can be saved by advance remote detection of reduced blood oxygen saturation.
Show moreFeb 2021 • Current Opinion in Electrochemistry 25, 100620, 2021
Alisa Kozhushner, Noam Zion, Lior Elbaz
The recent rise in the activity of platinum group metal–free oxygen reduction reaction catalysts for polymer electrolyte fuel cells, made them very interesting alternative for Pt-based catalysts. Currently, the application of this family of catalysts in fuel cells is impeded by their relatively low durability and stability. The lack of simple methods to follow the specific degradation of these catalysts in situ and in operando fuel cells inhibits durability and stability studies, where the key catalyst performance descriptor is the turnover frequency, for which the electrochemical site density needs to be accurately measured. Herein, the most commonly available techniques for measuring the active site density were surveyed, along with their advantages and disadvantages, leading to the conclusion that only electrochemical techniques such as square wave voltammetry and Fourier transform alternating current voltammetry can be used …
Show moreFeb 2021 • Advanced Functional Materials
Sandipan Maiti, Hadar Sclar, Rosy Sharma, Noam Vishkin, Miryam Fayena‐Greenstein, Judith Grinblat, Michael Talianker, Larisa Burstein, Nickolay Solomatin, Ortal Tiurin, Yair Ein‐Eli, Malachi Noked, Boris Markovsky, Doron Aurbach
The active role of alumina, pentalithium aluminate (Li5AlO4, Li‐aluminate), and pentasodium aluminate (Na5AlO4, Na‐aluminate) as the surface protection coatings produced via atomic layer deposition on Li and Mn‐rich NCM cathode materials 0.33Li2MnO3·0.67LiNi0.4Co0.2Mn0.4O2 is discussed. A notable improvement in the electrochemical behavior of the coated cathodes has been found while tested in Li‐coin cells at 30 °C. Though all the coated cathodes demonstrate enhanced electrochemical cycling and rate performances, Na‐aluminate coated cathodes exhibit exemplary behavior. Prolonged cycling and rate capability testing demonstrate that after more than 400 cycles at 1 C rate, the uncoated cathode delivers only 63 mAh g−1, while those with alumina, Li‐aluminate, and Na‐aluminate coatings exhibit approximately two times higher specific capacities. The coated cathodes display steady average …
Show moreFeb 2021 • Nanomaterials
Arumugam Saravanan, Moorthy Maruthapandi, Poushali Das, John HT Luong, Aharon Gedanken
Carbon dots (CDs) were obtained from medicinal turmeric leaves (Curcuma longa) by a facile one-step hydrothermal method and evaluated for their bactericidal activities against two gram-negative; Escherichia coli, Klebsiella pneumoniae, and two gram-positive counterparts; Staphylococcus aureus, S. epidermidis. The CDs exhibited spherical shapes with a mean size of 2.6 nm. The fluorescence spectra of CDs revealed intense fluorescence at λ ex/em= 362/429 nm with a bright blue color in an aqueous solution. The CDs showed strong photostability under various environmental conditions (pH, salt, and UV-radiation). The complete bactericidal potency of CDs was 0.25 mg/mL for E. coli and S. aureus after 8 h of exposure, while for K. pneumoniae, and S. epidermidis, the CDs at 0.5 mg/mL good antibacterial effect within 8 h and complete eradication after 24 h of exposure is observed. The release of reactive oxygen species played a crucial role in the death of the bacterial cell. The present study provides a strategy for the preparation of CDs from a medicinal plant and their potential antibacterial activities against four common contagious pathogens. View Full-Text
Show moreFeb 2021 • Current Opinion in Electrochemistry 25, 100620, 2021
Alisa Kozhushner, Noam Zion, Lior Elbaz
The recent rise in the activity of platinum group metal–free oxygen reduction reaction catalysts for polymer electrolyte fuel cells, made them very interesting alternative for Pt-based catalysts. Currently, the application of this family of catalysts in fuel cells is impeded by their relatively low durability and stability. The lack of simple methods to follow the specific degradation of these catalysts in situ and in operando fuel cells inhibits durability and stability studies, where the key catalyst performance descriptor is the turnover frequency, for which the electrochemical site density needs to be accurately measured. Herein, the most commonly available techniques for measuring the active site density were surveyed, along with their advantages and disadvantages, leading to the conclusion that only electrochemical techniques such as square wave voltammetry and Fourier transform alternating current voltammetry can be used …
Show moreFeb 2021 • ChemElectroChem
Bibhudatta Malik, Kalimuthu Vijaya Sankar, Rajashree Konar, Yoed Tsur, Gilbert Daniel Nessim
We designed a heterostructure of Fe3S4@ Ni3S2, as a potent oxygen evolution reaction (OER) electrocatalyst in an alkaline medium. Intriguingly, Fe3S4@ Ni3S2 exhibits low onset potential of290 mV and overpotential of 360 mV at a current density of 10 mA cm-2. We examined the OER kinetics of Fe3S4@ Ni3S2 using distribution function of relaxation times (DFRT), which are attained with the help of impedance spectroscopy genetic programming (ISGP). ISGP reveals the occurrences of three events of OER, manifested as peaks in the DFRT, such as active material or pores (P2), charge transfer (P1’), and production rate of intermediates (P1) in case of Fe3S4@ Ni3S2 at different faradic overpotentials. The effective resistance of each phenomenon can be easily calculated. It decreases with an increase in conductivity at high overpotentials for all the three, which suggests the high performance of the as-synthesized composite due to faster kinetics.
Show moreFeb 2021 • Journal of Applied Toxicology
Alessia Bertero, Graziano Colombo, Cristina Cortinovis, Virginia Bassi, Elisa Moschini, Nicholas Bellitto, Maria Chiara Perego, Marco Albonico, Emanuela Astori, Isabella Dalle‐Donne, Aharon Gedanken, Ilana Perelshtein, Paride Mantecca, Francesca Caloni
The use of CuO nanoparticles (NPs) has increased greatly and their potential effects on human health need to be investigated. Differentiated Caco‐2 cells were treated from the apical (Ap) and the basolateral (Bl) compartment with different concentrations (0, 10, 50 and 100 μg/mL) of commercial or sonochemically synthesized (sono) CuO NPs. Sono NPs were prepared in ethanol (CuOe) or in water (CuOw), obtaining CuO NPs differing in size and shape. The effects on the Caco‐2 cell barrier were assessed via transepithelial electrical resistance (TEER) evaluation just before and after 1, 2 and 24 hours of exposure and through the analysis of cytokine release and biomarkers of oxidative damage to proteins after 24 hours. Sono CuOe and CuOw NPs induced a TEER decrease with a dose‐dependent pattern after Bl exposure. Conversely, TEER values were not affected by the Ap exposure to commercial CuO NPs …
Show moreFeb 2021 • Energy Technology
Kobby Saadi, Michael Kuettinger, Peter Fischer, David Zitoun
The reversible and fast redox kinetics of bromine/bromide makes it a desirable couple as a catholyte in redox‐flow batteries (RFBs). In principle, the highest possible energy density is obtained with hydrogen‐bromine RFBs. Bromine sequestration agents, also called bromine complexing agents (BCAs), bind bromine in a non‐miscible phase and can, therefore, reduce the vapor pressure of bromine, mitigate its crossover, and result in higher practical range of electrolyte concentration. Therefore, BCAs can enhance the battery's safety and competitivity by significantly decreasing the cost of components. To date, BCAs are commonly used in membrane‐free bromine systems, which cannot provide the high current density demonstrated in hydrogen‐bromine RFBs. Herein, the drastic limitations encountered are shown while operating a hydrogen‐bromine RFB with a standard perfluorinated sulfonic acid membrane due …
Show moreFeb 2021 • Optics Express
Gal Chen, Abhijit Sanjeev, Vismay Trivedi, Javier Garcia, Ricardo Rubio, Zeev Zalevsky
Time multiplexing is a super-resolution technique that sacrifices time to overcome the resolution reduction obtained because of diffraction. There are many super resolution methods based on time multiplexing, but all of them require a priori knowledge of the time changing encoding mask, which is projected on the object and used to encode and decode the high-resolution information. In this paper, we present a time multiplexing technique that does not require the a priori knowledge on the projected encoding mask. First, the theoretical concept of the technique is demonstrated; then, numerical simulations and experimental results are presented.
Show moreFeb 2021 • The Journal of Physical Chemistry B
Anil R Mhashal, Dan Thomas Major
Calculation of temperature-dependent kinetic isotope effects (KIE) in enzymes presents a significant theoretical challenge. Additionally, it is not trivial to identify enzymes with available experimental accurate intrinsic KIEs in a range of temperatures. In the current work, we present a theoretical study of KIEs in the primitive R67 dihydrofolate reductase (DHFR) enzyme and compare with experimental work. The advantage of R67 DHFR is its significantly lower kinetic complexity compared to more evolved DHFR isoforms. We employ mass-perturbation-based path-integral simulations in conjunction with umbrella sampling and a hybrid quantum mechanics–molecular mechanics Hamiltonian. We obtain temperature-dependent KIEs in good agreement with experiments and ascribe the temperature-dependent KIEs primarily to zero-point energy effects. The active site in the primitive enzyme is found to be poorly …
Show moreFeb 2021 • arXiv preprint arXiv:2102.12856
Marc Jankowski, Carsten Langrock, Boris Desiatov, Marko Loncar, MM Fejer
We demonstrate a new approach to supercontinuum generation and carrier-envelope-offset detection in dispersion-engineered nanophotonic waveguides based on saturated second-harmonic generation of femtosecond pulses. In contrast with traditional approaches based on self-phase modulation, this technique simultaneously broadens both harmonics by generating rapid amplitude modulations of the field envelopes. The generated supercontinuum produces coherent carrier-envelope-offset beatnotes in the overlap region that remain in phase across 100's of nanometers of bandwidth while requiring 10 picojoules of pulse energy.
Show moreFeb 2021 • Entropy
M Hidalgo-Soria, Eli Barkai, Stanislav Burov
We study a two state “jumping diffusivity” model for a Brownian process alternating between two different diffusion constants, D+> D−, with random waiting times in both states whose distribution is rather general. In the limit of long measurement times, Gaussian behavior with an effective diffusion coefficient is recovered. We show that, for equilibrium initial conditions and when the limit of the diffusion coefficient D−⟶ 0 is taken, the short time behavior leads to a cusp, namely a non-analytical behavior, in the distribution of the displacements P (x, t) for x⟶ 0. Visually this cusp, or tent-like shape, resembles similar behavior found in many experiments of diffusing particles in disordered environments, such as glassy systems and intracellular media. This general result depends only on the existence of finite mean values of the waiting times at the different states of the model. Gaussian statistics in the long time limit is achieved due to ergodicity and convergence of the distribution of the temporal occupation fraction in state D+ to a δ-function. The short time behavior of the same quantity converges to a uniform distribution, which leads to the non-analyticity in P (x, t). We demonstrate how super-statistical framework is a zeroth order short time expansion of P (x, t), in the number of transitions, that does not yield the cusp like shape. The latter, considered as the key feature of experiments in the field, is found with the first correction in perturbation theory.
Show moreFeb 2021 • Scientific Reports
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 …
Show moreFeb 2021 • Nature Machine Intelligence
Itai Orr, Moshik Cohen, Zeev Zalevsky
In the version of this Article originally published, the colour bars labelled ‘Power (dB)’in Figs. 1–3, 5, 6 were incorrect; they should have been labelled ‘Amplitude (dB)’. In Fig. 5d, the colour bar labelled ‘Confidence level (dB)’was incorrect; it should have been labelled ‘Amplitude (dB)’. This has now been corrected.
Show moreFeb 2021
Rajiv Ramanujam Prabhakar, Thomas Moehl, Dennis Friedrich, Marinus Kunst, Sudhanshu Shukla, Damilola Adeleye, Vinayaka H Damle, Sebastian Siol, Wei Cui, Laxman Gouda, Jihye Suh, Yaakov R Tischler, Roel van de Krol, David Tilley
Sb2Se3 has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, despite its binary nature, Sb2Se3 has a complex defect chemistry, which reduces the maximum photovoltage that can be obtained. Thus, it is important to understand these defects and to develop passivation strategies in order to further improve this material. In this work, a comprehensive investigation of the charge carrier dynamics of Sb2Se3 and the influence of sulfur treatment on its optoelectronic properties was performed using time resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy and low frequency Raman spectroscopy (LFRS). The key finding in this work is that upon sulfur treatment of Sb2Se3, the carrier lifetime is increased by the passivation of deep defects in Sb2Se3 in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased radiative recombination efficiency and decreased deep defect level emission (PL), and improved long-range order in the material (LFRS). These findings provide crucial insights into the defect passivation mechanisms in Sb2Se3 paving the way for developing highly efficient PEC and PV devices.
Show moreFeb 2021 • Scientific reports
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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