1988 articles

69 publishers

Join mailing list

Dec 2020 • Carbon

Mesoporous carbon materials with enantioselective surface obtained by nanocasting for selective adsorption of chiral molecules from solution and the gas phase

Milena Perovic, Sapir Shekef Aloni, Yitzhak Mastai, Martin Oschatz

Separation of enantiomers is an everlasting challenge in chemistry, catalysis, and synthesis of pharmaceuticals. The design and fabrication of chiral adsorbent materials is a promising way to increase the surface area of chiral information, as well as to maximize the available surface for the adsorption of one enantiomer. Porous materials such as silica or metal-organic-frameworks are established compounds in this field, due to their well-defined surface structure and ease of functionalization with chiral groups. As another class of porous materials, carbons provide the advantages of high thermal and chemical stability, resistance against moisture, electrical conductivity, and widely tunable pore size. Although they are well established in many adsorption-related applications, carbons received far less attention in enantioselective adsorption processes because the controlled functionalization of their surface is rather …

Show more

Dec 2020 • The Journal of Physical Chemistry C

Monte Carlo-and Simulated-Annealing-Based Funneled Approach for the Prediction of Cation Ordering in Mixed Transition-Metal Oxide Materials

Sooraj Kunnikuruvan, Arup Chakraborty, Dan Thomas Major

The development of cathode materials with good electrochemical performance is vital to the effort to design rechargeable batteries for applications such as electric mobility. Li-intercalated mixed transition-metal layered oxides such as LiNixCoyMn(1–x–y)O2 (NCM) and LiNixCoyAl(1–x–y)O2 (NCA) have gained considerable attention due to their good electrochemical properties. The properties of these materials are strongly affected by the arrangement of ions in their crystal lattice, yet accurate determination of this arrangement using experiments and theory remains a challenge. Here, we present a hybrid approach based on Monte Carlo (MC) and simulated annealing (SA) in conjunction with an empirical potential to determine the most probable ionic arrangements from a large number of possibilities. The MCSA approach is followed by a density functional theory (DFT)-based rescoring to determine the energetically …

Show more

Dec 2020 • Applied Surface Science

Laser-induced backward transfer of monolayer graphene

Matthew Praeger, Symeon Papazoglou, Amaia Pesquera, Amaia Zurutuza, Adi Levi, Doron Naveh, Ioanna Zergioti, Robert W Eason, Ben Mills

Laser-induced backward transfer (LIBT) has been demonstrated as a viable technique for precise, localised deposition of microscale regions of graphene. Single femtosecond laser pulses, shaped spatially using a digital micromirror device (DMD), were incident on a pre-prepared sample of graphene-coated nickel (the donor substrate) through a transparent glass receiver substrate. Under optimal laser exposure conditions, and in a low-pressure gas environment, circular regions of graphene with approximately 30 µm diameter were successfully transferred from the donor to the receiver substrate as confirmed by optical and electron microscopy and Raman spectroscopy. The hypothesis that rapid thermal expansion of the nickel could drive the transfer process is explored and is shown to be plausible through some simple calculations. This LIBT technique for transfer of this archetypal 2D material has many potential …

Show more

Dec 2020 • Physical Review Research

Efficient simulatability of continuous-variable circuits with large Wigner negativity

Laura García-Álvarez, Cameron Calcluth, Alessandro Ferraro, Giulia Ferrini

Discriminating between quantum computing architectures that can provide quantum advantage from those that cannot is of crucial importance. From the fundamental point of view, establishing such a boundary is akin to pinpointing the resources for quantum advantage; from the technological point of view, it is essential for the design of nontrivial quantum computing architectures. Wigner negativity is known to be a necessary resource for computational advantage in several quantum-computing architectures, including those based on continuous variables (CVs). However, it is not a sufficient resource, and it is an open question under which conditions CV circuits displaying Wigner negativity offer the potential for quantum advantage. In this work we identify vast families of circuits that display large, possibly unbounded, Wigner negativity, and yet are classically efficiently simulatable, although they are not recognized as …

Show more

Dec 2020 • Critical Care Explorations

Frequency and analysis of unplanned extubation in coronavirus disease 2019 patients

Anoop K Chhina, Gary E Loyd, Trevor J Szymanski, Katherine A Nowak, William T Peruzzi, Nicholas S Yeldo, Xiaoxia Han, Lotfi S Kerzabi, Dragos M Galusca, Simona Cazacu, Chaya Brodie, Donald H Penning

Objectives:To determine if patients with coronavirus disease 2019 had a greater number of unplanned extubations resulting in reintubations than in patients without coronavirus disease 2019.Design:Retrospective cohort study comparing the frequency of unplanned extubations resulting in reintubations in a group of coronavirus disease 2019 patients to a historical (noncoronavirus disease 2019) control group.Setting:This study was conducted at Henry Ford Hospital, an academic medical center in Detroit, MI. The historical noncoronavirus disease 2019 patients were treated in the 68 bed medical ICU. The coronavirus disease 2019 patients were treated in the coronavirus disease ICU, which included the 68 medical ICU beds, 18 neuro-ICU beds, 32 surgical ICU beds, and 40 cardiovascular ICU beds, as the medical ICU was expanded to these units at the peak of the pandemic in Detroit, MI.Patients:The coronavirus …

Show more

Dec 2020 • Journal of nanobiotechnology

Ultrasensitive haptoglobin biomarker detection based on amplified chemiluminescence of magnetite nanoparticles

Narsingh R Nirala, Yifat Harel, Jean-Paul Lellouche, Giorgi Shtenberg

Haptoglobin is an acute-phase protein used as predicting diagnostic biomarker both in humans (i.e., diabetes, ovarian cancer, some neurological and cardiovascular disorders) and in animals (e.g., bovine mastitis). The latter is a frequent disease of dairy industry with staggering economical losses upon decreased milk production and increased health care costs. Early stage diagnosis of the associated diseases or inflammation onset is almost impossible by conventional analytical manners. The present study demonstrates a simple, rapid, and cost-effective label-free chemiluminescence bioassay based on magnetite nanoparticles (MNPs) for sensitive detection of haptoglobin by employing the specific interaction of hemoglobin-modified MNPs. The resulting haptoglobin-hemoglobin complex inhibits the peroxidase-like activity of luminol/H2O2-hemoglobin-MNPs sensing scheme and reduces the chemiluminescence intensities correspondingly to the innate haptoglobin concentrations. Quantitative detection of bovine haptoglobin was obtained within the range of 1 pg mL−1 to 1 µg mL−1, while presenting 0.89 pg mL−1 limit of detection. Moreover, the influence of causative pathogenic bacteria (i.e., Streptococcus dysgalactiae and Escherichia coli) and somatic cell counts (depicting healthy, sub-clinical and clinical mastitis) on the emitted chemiluminescence radiation were established. The presented bioassay quantitative performances correspond with a standardized assay kit in differentiating dissimilar milk qualities. Overall, the main advantage of the presented sensing concept is the ability to detect haptoglobin, at clinically relevant concentrations …

Show more

Dec 2020 • Journal of the Electrochemical Society

Evaluating the high-voltage stability of conductive carbon and ethylene carbonate with various lithium salts

Michael Metzger, Patrick Walke, Sophie Solchenbach, Gregory Salitra, Doron Aurbach, Hubert A Gasteiger

The anodic stability of conductive carbon and alkyl carbonate-based electrolyte solvents is a crucial requirement for the success of high-voltage lithium-ion cells, particularly at elevated temperatures. In order to quantify the oxidative stability of ethylene carbonate (EC), a critical component of lithium-ion battery electrolytes, and conductive carbons, we have evaluated the stability of a 13 C-labeled conductive carbon and an EC-based electrolyte up to 5.5 V vs Li+/Li. We examined the behavior between 25 C and 60 C for four different lithium salts (LiClO 4, LiPF 6, LiTFSI, and LiBF 4). This is done by means of On-line Electrochemical Mass Spectrometry (OEMS), whereby the isotopically labeled carbon is used to differentiate between the CO and CO 2 evolution from the oxidation of the conductive carbon (13 CO/13 CO 2) and of the electrolyte (12 CO/12 CO 2). Our analysis reveals that conductive carbon is stable with …

Show more

Dec 2020 • Environmental Microbiology

Characterization of PfiT/PfiA toxin–antitoxin system of Pseudomonas aeruginosa that affects cell elongation and prophage induction

Itzhak Zander, Ester Shmidov, Shira Roth, Yossi Ben‐David, Irit Shoval, Sivan Shoshani, Amos Danielli, Ehud Banin

Toxin–antitoxin (TA) systems are small genetic modules usually consisting of two elements—a toxin and an antitoxin. The abundance of TA systems among various bacterial strains may indicate an important evolutionary role. Pseudomonas aeruginosa, which can be found in a variety of niches in nature, is an opportunistic pathogen for various hosts. While P. aeruginosa strains are very versatile and diverse, only a few TA systems were characterized in this species. Here, we describe a newly characterized TA system in P. aeruginosa that is encoded within the filamentous Pf4 prophage. This system, named PfiT/PfiA, is a homologue of the ParE/YefM TA system. It is a type II TA system, in which the antitoxin is a protein that binds the toxic protein and eliminates the toxic effect. PfiT/PfiA carries several typical type II characteristics. Specifically, it constitutes two small genes expressed in a single operon, PfiT inhibits …

Show more

Dec 2020 • Polymers

Engineering of Doxorubicin-Encapsulating and TRAIL-Conjugated Poly (RGD) Proteinoid Nanocapsules for Drug Delivery Applications

Elad Hadad, Safra Rudnick-Glick, Ella Itzhaki, Matan Y Avivi, Igor Grinberg, Yuval Elias, Shlomo Margel

Proteinoids are non-toxic biodegradable polymers prepared by thermal step-growth polymerization of amino acids. Here, P (RGD) proteinoids and proteinoid nanocapsules (NCs) based on D-arginine, glycine, and L-aspartic acid were synthesized and characterized for targeted tumor therapy. Doxorubicin (Dox), a chemotherapeutic drug used for treatment of a wide range of cancers, known for its adverse side effects, was encapsulated during self-assembly to form Dox/P (RGD) NCs. In addition, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which can initiate apoptosis in most tumor cells but undergoes fast enzyme degradation, was stabilized by covalent conjugation to hollow P (RGD) NCs. The effect of polyethylene glycol (PEG) conjugation was also studied. Cytotoxicity tests on CAOV-3 ovarian cancer cells demonstrated that Dox/P (RGD) and TRAIL-P (RGD) NCs were as effective as free Dox and TRAIL with cell viability of 2% and 10%, respectively, while PEGylated NCs were less effective. Drug-bearing P (RGD) NCs offer controlled release with reduced side effects for improved therapy. View Full-Text

Show more

Dec 2020 • Nature Physics

Weak-to-strong transition of quantum measurement in a trapped-ion system

Yiming Pan, Jie Zhang, Eliahu Cohen, Chun-wang Wu, Ping-Xing Chen, Nir Davidson

Quantum measurement remains a puzzle through its stormy history from the birth of quantum mechanics to state-of-the-art quantum technologies. Two complementary measurement schemes have been widely investigated in a variety of quantum systems: von Neumann’s projective ‘strong’measurement and Aharonov’s weak measurement. Here, we report the observation of a weak-to-strong measurement transition in a single trapped 40 Ca+ ion system. The transition is realized by tuning the interaction strength between the ion’s internal electronic state and its vibrational motion, which play the roles of the measured system and the measuring pointer, respectively. By pre-and post-selecting the internal state, a pointer state composed of two of the ion’s motional wavepackets is obtained, and its central-position shift, which corresponds to the measurement outcome, demonstrates the transition from the weak-value …

Show more

Dec 2020 • arXiv preprint arXiv:2012.12069

Ultrafast non-destructive measurement of the quantum state of light using free electrons

Alexey Gorlach, Aviv Karnieli, Raphael Dahan, Eliahu Cohen, Avi Pe'er, Ido Kaminer

Since the birth of quantum optics, the measurement of quantum states of nonclassical light has been of tremendous importance for advancement in the field. To date, conventional detectors such as photomultipliers, avalanche photodiodes, and superconducting nanowires, all rely at their core on linear excitation of bound electrons with light, posing fundamental restrictions on the detection. In contrast, the interaction of free electrons with light in the context of quantum optics is highly nonlinear and offers exciting possibilities. The first experiments that promoted this direction appeared over the past decade as part of photon-induced nearfield electron microscopy (PINEM), wherein free electrons are capable of high-order multi-photon absorption and emission. Here we propose using free electrons for quantum-optical detection of the complete quantum state of light. We show how the precise control of the electron before and after its interaction with quantum light enables to extract the photon statistics and implement full quantum state tomography using PINEM. This technique can reach sub-attosecond time resolutions, measure temporal coherence of any degree (e.g., g(1), g(2)), and simultaneously detect large numbers of photons with each electron. Importantly, the interaction of the electron with light is non-destructive, thereby leaving the photonic state (modified by the interaction) intact, which is conceptually different from conventional detectors. By using a pulse of multiple electrons, we envision how PINEM quantum detectors could achieve a single-shot measurement of the complete state of quantum light, even for non-reproducible emission …

Show more

Dec 2020 • Physical Review D

Realism and causality. II. Retrocausality in energetic causal sets

Eliahu Cohen, Marina Cortês, Avshalom C Elitzur, Lee Smolin

We describe a new form of retrocausality, which is found in the behavior of a class of causal set theories, called energetic causal sets (ECS). These are discrete sets of events, connected by causal relations. They have three orders:(1) a birth order, which is the order in which events are generated; this is a total order which is the true causal order,(2) a dynamical partial order, which prescribes the flows of energy and momentum among events,(3) an emergent causal order, which is defined by the geometry of an emergent Minkowski spacetime, in which the events of the causal sets are embedded. However, the embedding of the events in the emergent Minkowski spacetime may preserve neither the true causal order in (1) nor correspond completely with the microscopic partial order in (2). We call this disordered causality, and we here demonstrate its occurrence in specific ECS models. This is the second in a series of …

Show more

Dec 2020 • Physical Review B

Observations of symmetry-induced topological mode steering in a reconfigurable elastic plate

Kun Tang, M Makwana, Richard V Craster, Patrick Sebbah

We experimentally investigate the valley-Hall effect for interfacial edge states, highlighting the importance of the modal patterns between geometrically distinct regions within a structured elastic plate. These experiments, for vibration, are at a scale where detailed measurements are taken throughout the system and not just at the input/output ports; this exposes the coupling between geometrically distinct modes that underlie the differences between wave transport around gentle and sharp bends.

Show more

Dec 2020 • Genome biology

Purifying selection of long dsRNA is the first line of defense against false activation of innate immunity

Michal Barak, Hagit T Porath, Gilad Finkelstein, Binyamin A Knisbacher, Ilana Buchumenski, Shalom Hillel Roth, Erez Y Levanon, Eli Eisenberg

Mobile elements comprise a large fraction of metazoan genomes. Accumulation of mobile elements is bound to produce multiple putative double-stranded RNA (dsRNA) structures within the transcriptome. These endogenous dsRNA structures resemble viral RNA and may trigger false activation of the innate immune response, leading to severe damage to the host cell. Adenosine to inosine (A-to-I) RNA editing is a common post-transcriptional modification, abundant within repetitive elements of all metazoans. It was recently shown that a key function of A-to-I RNA editing by ADAR1 is to suppress the immunogenic response by endogenous dsRNAs. Here, we analyze the transcriptomes of dozens of species across the Metazoa and identify a strong genomic selection against endogenous dsRNAs, resulting in their purification from the canonical transcriptome. This purifying selection is especially strong for long and nearly perfect dsRNAs. These are almost absent from mRNAs, but not pre-mRNAs, supporting the notion of selection due to cytoplasmic processes. The few long and nearly perfect structures found in human transcripts are weakly expressed and often heavily edited. Purifying selection of long dsRNA is an important defense mechanism against false activation of innate immunity. This newly identified principle governs the integration of mobile elements into the genome, a major driving force of genome evolution. Furthermore, we find that most ADAR1 activity is not required to prevent an immune response to endogenous dsRNAs. The critical targets of ADAR1 editing are, likely, to be found mostly in non-canonical transcripts.

Show more

Dec 2020 • ACS Applied Nano Materials

Carbon dots for heavy-metal sensing, pH-sensitive cargo delivery, and antibacterial applications

Poushali Das, Moorthy Maruthapandi, Arumugam Saravanan, Michal Natan, Gila Jacobi, Ehud Banin, Aharon Gedanken

Currently, the technologies accompanying the usage of waste materials for the fabrication of innovative useful materials have been significantly advanced. For the same purpose, a possible sustainable approach was demonstrated for the utilization of jute caddies, known as jute industry waste. From the industrial waste, carbon dots (CDs) were sonochemically prepared, followed by their surface modification with benzalkonium chloride (BZC) to yield waste jute-derived fluorescent surface-quaternized CDs (JB-CDs), which exhibit excellent water solubility, excitation-dependent emission, and good photostability, and were utilized as a fluorescent nanoswitch to detect inorganic pollutants, such as chromium (VI) [Cr(VI)] ions, in aqueous solutions. JB-CDs can detect Cr(VI) concentrations as low as 0.03 μM through luminescence quenching (“turn-off”) and further recover their fluorescence (“turn-on”) selectively for …

Show more

Dec 2020 • Colloids and Surfaces A: Physicochemical and Engineering Aspects

In-situ thin coating of silica micro/nano-particles on polymeric films and their anti-fogging application

Sharon Bretler, Naftali Kanovsky, Taly Iline-Vul, Sarit Cohen, Shlomo Margel

Polymeric films, e.g., polyethylene (PE), coated with a thin layer of silica micro/nano-particles (SiO2 M/NPs) were prepared using a modified Stöber method in the presence of corona treated and non-treated PE films. The obtained films were washed of excess reagents and non-bonded (free) SiO2 M/NPs and dried. Only the corona-treated PE films were coated with a thin layer of SiO2 M/NPs while the non-treated films were almost empty of bound SiO2 particles. PE films composed of bound mesoporous silica NPs were similarly prepared with the addition of cetyltrimethylammonium bromide (CTAB) in the polymerization process. The effect of various polymerization parameters, e.g., tetraethylorthosilicate (TEOS) concentration, ammonium hydroxide concentration and the volume ratio [ethanol]/[water], on the diameter and diameter distribution of the free and surface bound particles were elucidated. Characterization of …

Show more

Dec 2020 • Journal of the American Chemical Society

The impression of a nonexisting catalytic effect: the role of CotB2 in guiding the complex biosynthesis of cyclooctat-9-en-7-ol

Keren Raz, Ronja Driller, Nicole Dimos, Marion Ringel, Thomas Brück, Bernhard Loll, Dan Thomas Major

Terpene synthases generate terpenes employing diversified carbocation chemistry, including highly specific ring formations, proton and hydride transfers, and methyl as well as methylene migrations, followed by reaction quenching. In this enzyme family, the main catalytic challenge is not rate enhancement, but rather structural and reactive control of intrinsically unstable carbocations in order to guide the resulting product distribution. Here we employ multiscale modeling within classical and quantum dynamics frameworks to investigate the reaction mechanism in the diterpene synthase CotB2, commencing with the substrate geranyl geranyl diphosphate and terminating with the carbocation precursor to the final product cyclooctat-9-en-7-ol. The 11-step in-enzyme carbocation cascade is compared with the same reaction in the absence of the enzyme. Remarkably, the free energy profiles in gas phase and in CotB2 …

Show more

Dec 2020 • physica status solidi (a)

Laser Recording in Chalcogenide Glass Films: Driving Forces and Kinetics of the Mass Transfer

Yuri S Kaganovskii, Hadar Genish, Michael Rosenbluh

Herein, precision recording of indented dots and lines in As10Se90 and As2S3 chalcogenide glass films by a focused laser beam is demonstrated and the kinetics and mechanisms of mass transfer under illumination are studied. Due to inhomogeneous intensity distribution and local heating of the film at the focal point, the beam at rest produces an indentation whose depth increases with time and laser power. Illumination by a moving beam leads to formation of groves whose morphology depends on the beam speed and power. At low light intensities, formation of the indentations occurs in the solid phase, due to photoinduced radial diffusion of the film constituents coupled with electrons and holes created by light. The two main driving forces present are: 1) a lateral steady‐state electric field formed due to different mobilities of electrons and holes and 2) driving force of thermodiffusion (Soret effect). At high light …

Show more

Dec 2020 • Nature Energy

Minimum doping densities for p–n junctions

Thomas Kirchartz, David Cahen

MATTERS ARISING NATURE ENERGY volume 9, where σn and σp are the capture cross-sections for electrons and holes into the defect that dominates recombination. To avoid the condition nσn= pσp, doping may be helpful, as shown in Fig. 2, because it induces an asymmetry at least in n versus p, that may help to reduce the absorber volume where nσn= pσp to a small region 10. Thus, p–n junctions in lead-halide perovskites could indeed be helpful to achieve higher efficiencies if deep defect densities and carrier mobilities are not adversely affected by higher doping densities and if those higher doping densities can actually be achieved technologically.This last point may well be key, as ap–n junction is not a thermodynamically stable situation; rather it is a kinetically stabilized one 11. The relatively high diffusion coefficients for atomic/ionic species in the lead-halide perovskites that have been reported in the …

Show more

Dec 2020 • Neuroscience Bulletin

Sex and death: Identification of feedback neuromodulation balancing reproduction and survival

Can Gao, Chao Guo, Qionglin Peng, Jie Cao, Galit Shohat-Ophir, Dong Liu, Yufeng Pan

Some semelparous organisms in nature mate as many times as they can in a single reproductive episode before death, while most iteroparous species including humans avoid such suicidal reproductive behavior. Animals naturally pursue more sex and the possible fatal consequence of excessive sex must be orchestrated by negative feedback signals in iteroparous species, yet very little is known about the regulatory mechanisms. Here we used Drosophila male sexual behavior as a model system to study how excessive sex may kill males and how the nervous system reacts to prevent death by sex. We found that continuous sexual activity by activating the fruitless-expressing neurons induced a fixed multi-step behavioral pattern ending with male death. We further found negative feedback in the fly brain to prevent suicidal sexual behavior by expression changes of the neurotransmitters acetylcholine and gamma …

Show more

Dec 2020 • Scientific reports

Human kidney clonal proliferation disclose lineage-restricted precursor characteristics

Osnat Cohen-Zontag, Rotem Gershon, Orit Harari-Steinberg, Itamar Kanter, Dorit Omer, Oren Pleniceanu, Gal Tam, Sarit Oriel, Herzel Ben-Hur, Guy Katz, Zohar Dotan, Tomer Kalisky, Benjamin Dekel, Naomi Pode-Shakked

In-vivo single cell clonal analysis in the adult mouse kidney has previously shown lineage-restricted clonal proliferation within varying nephron segments as a mechanism responsible for cell replacement and local regeneration. To analyze ex-vivo clonal growth, we now preformed limiting dilution to generate genuine clonal cultures from one single human renal epithelial cell, which can give rise to up to 3.4* 10 6 cells, and analyzed their characteristics using transcriptomics. A comparison between clonal cultures revealed restriction to either proximal or distal kidney sub-lineages with distinct cellular and molecular characteristics; rapidly amplifying de-differentiated clones and a stably proliferating cuboidal epithelial-appearing clones, respectively. Furthermore, each showed distinct molecular features including cell-cycle, epithelial-mesenchymal transition, oxidative phosphorylation, BMP signaling pathway and cell …

Show more


Powered by Articali