1975 articles

69 publishers

Join mailing list

Oct 2020 • Bioessays

Speculating on the Roles of Nuclear Speckles: How RNA‐Protein Nuclear Assemblies Affect Gene Expression

Sarah E Hasenson, Yaron Shav‐Tal

Nuclear speckles are eukaryotic nuclear bodies enriched in splicing factors. Their exact purpose has been a matter of debate. The different proposed roles of nuclear speckles are reviewed and an additional layer of function is put forward, suggesting that by accumulating splicing factors within them, nuclear speckles can buffer the nucleoplasmic levels of splicing factors available for splicing and thereby modulate splicing rates. These findings build on the already established model that nuclear speckles function as a storage/recycling site for splicing factors. Many studies have demonstrated proximity between nuclear speckles and sites of active transcription, suggesting that this juxtaposition can enhance the rates of gene expression. It is found that nuclear speckle disassembly increases splicing factor availability in the nucleoplasm, leading to an increase in splicing rates and faster release of nascent transcripts …

Show more

Oct 2020 • arXiv preprint arXiv:2010.12220

Classical and wave chaos in the transformation from curved to flat surfaces

Chenni Xu, Itzhack Dana, Li-Gang Wang, Patrick Sebbah

We study classical and wave chaotic dynamics of light both on a curved surface and on a table billiard with nonuniform distribution of refractive index. Inspired by the concept of transformation optics, we demonstrate that these two systems are fundamentally equivalent in terms of both light rays and waves, under a conformal coordinate transformation. This total equivalency allows us to study simultaneously a typical family of curved surfaces and their corresponding transformed billiards. Here we consider the truncated Tannery's pear and its equivalent flat billiard with non-uniform distribution of refractive index, when an off-centered hole is pierced to introduce chaos. We find that the degree of chaos is fully controlled by the single geometric parameter of Tannery's pears. This is proved by exploring in the transformed billiard the dependence with this geometric parameter of the Poincar\'{e} surface of section, the Lyapunov exponent and the the statistics of eigenmodes and eigenfrequency spectrum. Finally, a simple interpretation of our findings naturally emerges when considering transformed billiards, which allows to extend our prediction to other class of curved surfaces. The powerful analogy we reveal here between two a priori unrelated systems not only brings forward a novel approach to control the degree of chaos, but also provides potentialities for further studies and applications in various fields, such as billiards design, optical fibers, or laser microcavities.

Show more

Oct 2020 • Current Opinion in Systems Biology 24, 100-108, 2020

Germline immunoglobulin genes: disease susceptibility genes hidden in plain sight?

Andrew M Collins, Gur Yaari, Adrian J Shepherd, William Lees, Corey T Watson

Immunoglobulin genes are rarely considered as disease susceptibility genes despite their obvious and central contributions to immune function. This appears to be a consequence of historical views on antibody repertoire formation that no longer stand, and of difficulties that until recently surrounded the documentation of the suite of antibody genes in any individual. If these important genes are to be accessible to GWAS studies, allelic variation within the human population needs to be better documented, and a curated set of genomic variations associated with antibody genes needs to be formulated. Repertoire studies arising from the COVID-19 pandemic provide an opportunity to meet these needs, and may provide insights into the profound variability that is seen in outcomes to this infection.

Show more

Oct 2020 • Desalination

Thermally reduced graphene oxide as an electrode for CDI processes: A compromise between performance and scalability?

Ayelet Kalfa, Tirupathi Rao Penki, Izaak Cohen, Netanel Shpigel, Eran Avraham, Doron Aurbach, Dawei Liang, Qinghao Wu, Haining Wang, Yan Xiang

Capacitive deionization (CDI) is an alternative water desalination technology, which was investigated extensively in the last decade. The choice of electrodes' materials plays a major role in the electrosorption performance, affecting the whole desalination process. Graphene-based nanostructures in various types were extensively studied owing to their superior inherent physico-chemical properties. Whereas excellent electrosorption performance was reported – expressed in terms of salt adsorption capacity (SAC) or average salt adsorption rate (ASAR) – the cost-benefit of graphene-based electrodes, considering total production cost and much lower price of commercial activated carbon, is still controversial.Here, we explore partially exfoliated thermally reduced graphene oxide (GO) – denoted as PE-rGO – prepared by scalable low-temperature thermal exfoliation of GO under air atmosphere. PE-rGO displays a …

Show more

Oct 2020 • ACS omega

Mechanism underlying the emission of gases during the low-temperature oxidation of bituminous and lignite coal piles: The involvement of radicals

Tze’ela Taub, Aviv Hassid, Sharon Ruthstein, Haim Cohen

Coal is one of the major fuels for power generation, and it will continue in this capacity for the next several decades. Two types of coal are mainly used: lignite and bituminous coals. When exposed to air, post-mining, the coal surface undergoes LTO (low-temperature oxidation) at RT-150 °C according to the atmospheric oxygen level. The LTO process decreases the calorific value of the coal, and consequently, different gases are released [mainly carbon oxides (CO, CO2), water vapor, hydrogen (H2), and also some low molecular-weight organic gases (C1–5)]. Some of these gases are toxic and flammable. In extreme cases, fires erupt. The mechanism by which the molecular oxygen oxidizes the coal macromolecule at the temperature range of 30–150 °C (LTO process) is complex and also involves a chain of radical reactions that take place; however, the exact underlying mechanism is not yet clear. The LTO …

Show more

Oct 2020 • Ternary and Multinary Compounds, 741-744, 2020

Investigation of the defect chemistry of CuInSe2 by positron lifetime and electrical measurements

J Klais, HJ Müller, R Krause-Rehberg, David Cahen, Vera Lyakhovitskaya

In this study we present the determination of the defect chemistry and the electrical properties of CuInSe2 after controlled annealing steps. The samples were investigated with the positron annihilation method and the admittance spectroscopy.

Show more

Sep 2020 • ACS omega

Synthesis and Characterization of Poly (RGD) Proteinoid Polymers and NIR Fluorescent Nanoparticles of Optimal d, l-Configuration for Drug-Delivery Applications—In Vitro Study

Elad Hadad, Safra Rudnick-Glick, Igor Grinberg, Michal Kolitz-Domb, Jordan H Chill, Shlomo Margel

RGD sequence is a tripeptide composed of three amino acids: arginine (R), glycine (G), and aspartic acid (D). The RGD peptide has a high affinity to the integrin alpha v beta 3, which is overexpressed on the membrane of many cancer cells and is attracted to areas of angiogenesis. Proteinoids are biodegradable polymers based on amino acids which are formed by bulk thermal step-growth polymerization mechanism. Hollow proteinoid nanoparticles (NPs) may be formed via self-assembly process of the proteinoid polymers. We propose using novel RGD-based proteinoid polymers to manufacture NPs in which the RGD motif is self-incorporated in the proteinoid backbone. Such P(RGD) NPs can act both as a drug carrier (by encapsulation of a desired drug) and as a targeting delivery system. This article presents the synthesis of four RGD proteinoids with different RGD optical configurations, (d) or (l) arginine …

Show more

Sep 2020 • Nature Energy 5 (9), 646-656, 2020

Current status and future directions of multivalent metal-ion batteries

Yanliang Liang, Hui Dong, Doron Aurbach, Yan Yao

Batteries based on multivalent metals have the potential to meet the future needs of large-scale energy storage, due to the relatively high abundance of elements such as magnesium, calcium, aluminium and zinc in the Earth’s crust. However, the complexity of multivalent metal-ion chemistries has led to rampant confusions, technical challenges, and eventually doubts and uncertainties about the future of these technologies. In this Review, we clarify the key strengths as well as common misconceptions of multivalent metal-based batteries. We then examine the growth behaviour of metal anodes, which is crucial for their safety promises but hitherto unestablished. We further discuss scrutiny of anode efficiency and cathode storage mechanism pertaining to complications arising from electrolyte solutions. Finally, we critically review existing cathode materials and discuss design strategies to enable genuine multivalent …

Show more

Sep 2020 • Carbohydrate Polymers

Antibacterial activities of microwave-assisted synthesized polypyrrole/chitosan and poly (pyrrole-N-(1-naphthyl) ethylenediamine) stimulated by C-dots

Moorthy Maruthapandi, Kusha Sharma, John HT Luong, Aharon Gedanken

Polypyrrole grafted with chitosan (PPy-g-CS) and poly (pyrrole-N-(1-naphthyl) ethylenediamine, a copolymer, (COP) have been synthesized by a one-step microwave procedure with carbon dots(C-Dots) as initiators. The electrostatic interaction between the positively charged polymers and negatively charged microbial cell membranes is widely anticipated to be responsible for cellular lysis. However, Escherichia coli exposed to PPy-g-CS (zeta potential = +46.9 mV) was completely perished after 3 h while COP (zeta potential = +64.1 mV) exhibited no antimicrobial effect. The two polymers were capable of eradicating Staphylococcus aureus, implying the charged effect is the main mechanism of cell death. The two polymers could also chelate calcium and other nutrients as well as form an external barrier to suppress the penetration of essential nutrients to support microbial survival and proliferation. In particular …

Show more

Sep 2020 • APL Photonics

Temporal imaging with a high filling factor

Avi Klein, Inbar Sibony, Sara Meir, Hamootal Duadi, Michelle Y Sander, Moti Fridman

We demonstrate a temporal imaging system that can capture events with unknown time-of-arrival in the time domain without the need to synchronize the signal. The temporal imaging system is based on a time-lens that uses a high repetition-rate fiber laser for the pump wave together with a time-stretch scheme. After dispersion, the timing between adjacent pump pulses is smaller than the pulse width. Therefore, the signal interacts with one of the pump pulses with high probability, regardless of its arrival time. We discuss the intensity dependence and temporal aberrations of such an imaging system and demonstrate a direct temporal imaging of the buildup dynamics of solitons.

Show more

Sep 2020 • Advanced Composites and Hybrid Materials

Surfactant-assisted cerium oxide and its catalytic activity towards Fenton process for non-degradable dye

Bhawana Jain, Ajaya K Singh, Ayesha Hashmi, Md Abu Bin Hasan Susan, Jean-Paul Lellouche

Water pollution kills nearly 2 million people and costs trillions of dollars every year, which continuously threatens the survival of both human and animal species in the world. The textile industry is considered as pollutant-releasing industries in water. In this research work, we firstly report the synthesis of cerium oxide (CeO2) nanoparticles in the range of quantum dots (QDs). Syntheses of cerium oxide nanomaterials were assisted by using three different surfactants, i.e., sodium dodecyl sulfate (SDS; anionic), cetyltrimethylammonium bromide (CTAB; cationic), and cetylpyridinium chloride (CPC; cationic); the surfactants control the growth and particle size of the prepared material. The nanomaterials were characterized by UV-visible spectroscopy, X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, high-resolution transmission electron microscopy (HRTEM), and …

Show more

Sep 2020 • Drug Resistance Updates 52, 100704, 2020

Nanomedicine to target multidrug resistant tumors

Elise Lepeltier, Patricia Rijo, Flavio Rizzolio, Rachela Popovtzer, Vilma Petrikaite, Yehuda G Assaraf, Catherine Passirani

Nanomedicine employs nanotechnologies to develop innovative applications, and more specifically nano-objects in the field of human health, through exploitation of the physical, chemical and biological properties of materials at the nanoscale. The use of nanovehicles capable of transporting and releasing the active therapeutic payload into target cells, particularly in the case of cancer or inflammatory diseases, can also enhance diagnosis. Therefore, nanomedicines improve the benefit/risk ratio of drugs by increasing their bioavailability, selectivity, and efficacy in the target tissue, while reducing the necessary doses and hence diminishing untoward toxicity to healthy tissues. Overcoming multidrug resistance (MDR) to antitumor agents is a central goal of cancer research and therapeutics, making it possible to treat these diseases more accurately and effectively. The adaptability of nanomedicines e.g. modulation of …

Show more

Sep 2020 • Journal of The Electrochemical Society

Stabilization of Lithium Cobalt Phosphate Cathodes via Artificial Interphases

Sarah Taragin, Jan L Allen, Lin Ma, Malachi Noked, Marshall A Schroeder

Olivine LiCoPO 4 (LCP) exhibits a rare combination of high theoretical capacity (167 mAh g− 1), excellent thermal stability, and high redox potential (4.8 V vs vs Li/Li+), making it a promising candidate for high voltage lithium batteries. Despite these attractive properties, practical implementation of this electrode chemistry has been limited by stability issues at the cathode-electrolyte interface, including parasitic electrolyte reactions, surface decomposition of the electrode material, and Co dissolution. Carbon coating and substitutions of Co by Fe and other cations improve the performance, however the cycling stability needs further improvement. In an effort to address these issues, we deposited thin, conformal metal oxide surface coatings on substituted LCP powder and investigated the effects of these coatings on the performance of carbon-coated substituted LCP/MCMB graphite full cells with a standard carbonate …

Show more

Sep 2020 • Developmental Neurobiology

SEM/FIB Imaging for Studying Neural Interfaces

Itai Henn, Ayelet Atkins, Amos Markus, Gal Shpun, Hannah‐Noa Barad, Nairouz Farah, Yossi Mandel

Tissue and neural engineering for various regenerative therapies are rapidly growing fields. Of major interest is studying the complex interface between cells and various 3D structures by scanning electron microscopy with focused ion beam. Notwithstanding its unrivaled resolution, the optimal fixation, dehydration, and staining protocols of the samples while preserving the complex cell interface in its natural form, are highly challenging. The aim of this work was to compare and optimize staining and sample drying procedures in order to preserve the cells in their “life‐like state” for studying the cell interface with either 3D well‐like structures or gold‐coated mushroom‐shaped electrodes. The process involved chemical fixation using a combination of glutaraldehyde and formaldehyde, followed by gentle drying techniques in which we compared four methods: (critical point drying, hexamethyldisiloxane, repeats of …

Show more

Sep 2020 • Scientific reports

Osteopontin regulates biomimetic calcium phosphate crystallization from disordered mineral layers covering apatite crystallites

Taly Iline-Vul, Raju Nanda, Borja Mateos, Shani Hazan, Irina Matlahov, Ilana Perelshtein, Keren Keinan-Adamsky, Gerhard Althoff-Ospelt, Robert Konrat, Gil Goobes

Details of apatite formation and development in bone below the nanometer scale remain enigmatic. Regulation of mineralization was shown to be governed by the activity of non-collagenous proteins with many bone diseases stemming from improper activity of these proteins. Apatite crystal growth inhibition or enhancement is thought to involve direct interaction of these proteins with exposed faces of apatite crystals. However, experimental evidence of the molecular binding events that occur and that allow these proteins to exert their functions are lacking. Moreover, recent high-resolution measurements of apatite crystallites in bone have shown that individual crystallites are covered by a persistent layer of amorphous calcium phosphate. It is therefore unclear whether non-collagenous proteins can interact with the faces of the mineral crystallites directly and what are the consequences of the presence of a disordered …

Show more

Sep 2020 • Journal of Solid State Electrochemistry

Selected future tasks in electrochemical research related to advanced power sources

David Malka, Netanel Shpigel, Ran Attias, Doron Aurbach

The purpose of this short paper is to outline important research tasks related to electrochemical power sources. In fact, we can mention four main avenues related to electrochemical science connected to energy challenges, ie energy harvesting by photovoltaic cells, hydrogen economy (hydrogen production by electrolysis, followed by its effective storage and use in fuel cells), the energy-water nexus which is related to capacitive interactions (including important topics such as capacitive deionisation and the field of supercapacitors and related devices) and electrochemical energy storage and conversion by batteries.

Show more

Sep 2020 • Journal of Solid State Electrochemistry

Correction to: Selected future tasks in electrochemical research related to advanced power sources

David Malka, Netanel Shpigel, Ran Attias, Doron Aurbach

This original article contained a mistake.

Show more

Sep 2020 • Journal of The Electrochemical Society

Preface—Focus Issue on Battery Safety, Reliability and Mitigation

Boryann Liaw, Thomas P Barrera, Doron Aurbach

Battery reliability and safety are two key issues critically affecting the sustainability of battery technology and the entire supply chain. Reliability and safety are interrelated and inseparable. In this focus issue, sixty (60) articles have been published online. This is quite an accomplishment for the Journal of The Electrochemical Society, indicative of the importance of this subject matter. We would like to take this opportunity to emphasize the meaning of reliability and safety in a proper context. Reliability, in principle, refers to a cell’s ability to sustain its functionality for the intended use, not only in performance but also in consistency for all aspects of the functions and for resilience in the event of failures. The reliability issues could range from a material’s electrochemical stability, an electrode’s architectural stability, and a cell’s energetic stability under the influences of external stress factors (such as mechanical stresses …

Show more

Sep 2020 • Bioresource technology reports

An efficient method to produce 1, 4-pentanediol from the biomass of the algae Chlorella ohadi with levulinic acid as intermediate

Elena Benisvy-Aharonovich, Anat Zandany, Abed Saady, Yael Kinel-Tahan, Yaron Yehoshua, Aharon Gedanken

Today, the development of innovative methods for production of organic compounds from natural resources is essential topic for many research groups in the worldwide. Levulinic acid is a platform for many important organic processes in the synthesis of natural products, pharmaceuticals, plasticizers, drugs and various other additives. In addition, 1,4-pentanediol which is a product of reduction of levulinic acid, is a valuable raw material in the chemical industry. Here, we report a highly efficient method for the production of levulinic acid from Chlorella ohadi algae using hydrothermal hydrolysis process by using HCl. Our methodology shows that the levulinic acid can be obtained in almost 90% molar yield compared to the glucose in Chlorella ohadi. Finally, we describe a one step reaction for the completely conversion of levulinic acid into 1,4-pentadiol in water using S. cerevisiae yeast as a catalyst.

Show more

Sep 2020 • EMBO molecular medicine

A Parkinson's disease circ rna s resource reveals a link between circ slc 8a1 and oxidative stress

Mor Hanan, Alon Simchovitz, Nadav Yayon, Shani Vaknine, Roni Cohen‐Fultheim, Miriam Karmon, Nimrod Madrer, Talia Miriam Rohrlich, Moria Maman, Estelle R Bennett, David S Greenberg, Eran Meshorer, Erez Y Levanon, Hermona Soreq, Sebastian Kadener

Circular RNAs (circRNAs) are brain‐abundant RNAs of mostly unknown functions. To seek their roles in Parkinson's disease (PD), we generated an RNA sequencing resource of several brain region tissues from dozens of PD and control donors. In the healthy substantia nigra (SN), circRNAs accumulate in an age‐dependent manner, but in the PD SN this correlation is lost and the total number of circRNAs reduced. In contrast, the levels of circRNAs are increased in the other studied brain regions of PD patients. We also found circSLC8A1 to increase in the SN of PD individuals. CircSLC8A1 carries 7 binding sites for miR‐128 and is strongly bound to the microRNA effector protein Ago2. Indeed, RNA targets of miR‐128 are also increased in PD individuals, suggesting that circSLC8A1 regulates miR‐128 function and/or activity. CircSLC8A1 levels also increased in cultured cells exposed to the oxidative stress …

Show more

Sep 2020 • Langmuir

Nucleation and Growth of PbBrF Crystals at the Liquid Mercury–Electrolyte Interface Studied by Operando X-ray Scattering

Sven Festersen, Benjamin Runge, Christian Koops, Florian Bertram, Ben Ocko, Moshe Deutsch, Bridget M Murphy, Olaf M Magnussen

Detailed in operando studies of electrochemically induced PbBrF deposition at the liquid mercury/liquid electrolyte interface are presented. The nucleation and growth were monitored using time-resolved X-ray diffraction and reflectivity combined with electrochemical measurements, revealing a complex potential-dependent behavior. PbBrF deposition commences at potentials above −0.7 V with the rapid formation of an ultrathin adlayer of one unit cell thickness, on top of which (001)-oriented three-dimensional crystallites are formed. Two potential regimes are identified. At low overpotentials, slow growth of a low surface density film of large crystals is observed. At high overpotentials, crossover to a potential-independent morphology occurs, consisting of a compact PbBrF deposit with a saturation thickness of 25 nm, which forms within a few minutes. This potential behavior can be rationalized by the increasing …

Show more


Powered by Articali