BINA

This paper revisits the geometric foundations of electromagnetic theory, by studying Faraday's concept of field lines. We introduce "covariant electromagnetic field lines," a novel construct that extends traditional field line concepts to a covariant framework. Our work includes the derivation of a closed-form formula for the field line curvature in proximity to a moving electric charge, showcasing the curvature is always non-singular, including nearby a point charge. Our geometric framework leads to a geometric derivation of the Lorentz force equation and its first-order corrections, circumventing the challenges of self-force singularities and providing insights into the problem of radiation-reaction. This study not only provides a fresh geometric perspective on electromagnetic field lines but also opens avenues for future research in fields like quantum electrodynamics, gravitational field theory, and beyond.

This work presents an original method based on the variance properties of the microwave absorption spectrum of an ensemble of nitrogen vacancy centers in diamond. The spectrum is measured optically. A compact and simple device is designed to optimize the photon collection. We conduct a quantitative comparison of the ensemble's optical signal in both the visible and near infrared range. Using the enhanced signal-to-noise ratio achieved through the device geometry we perform real-time DC magnetometry at moderate light and microwave powers. Under these conditions, the amplitude of a DC magnetic field can be extracted from the variance of the microwave absorption spectrum in a fast and reproducible manner, without the burden of complex fitting techniques.

Understanding the physical underpinnings and geometry of molecular clusters is of great importance in many fields, ranging from studying the beginning of the universe to the formation of atmospheric particles. To this end, several approaches have been suggested, yet identifying the most stable cluster geometry (i.e., global potential energy minimum) remains a challenge, especially for highly symmetric clusters. Here, we suggest a new funneled Monte Carlo-based simulated annealing (SA) approach, which includes two key steps: generation of symmetrical clusters and classification of the clusters according to their geometry using machine learning (MCSA-ML). We demonstrate the merits of the MCSA-ML method in comparison to other approaches on several Lennard-Jones (LJ) clusters and four molecular clusters─Ser8(Cl–)2, H+(H2O)6, Ag+(CO2)8, and Bet4Cl–. For the latter of these clusters, the correct …

Surface characterization is essential for understanding chemical and electrochemical transformations occurring on surfaces or at interfaces. Battery electrode aging processes, biofilm growth, crystallization, and transport/signaling across cellular membranes are only a few examples of such phenomena. This special issue delves into applied electrochemistry and nonlinear optical techniques applicable to surface characterization.

The state‐of‐the‐art Platinum group metal (PGM)‐free oxygen reduction reaction (ORR) catalysts have been synthesized using the pyrolysis of iron, nitrogen, and carbon precursors, and result in highly active ORR catalysts, but their undefined structure limits their further development. Since the inspiration for these catalysts came from well‐defined structures of transition metal complexes, it is important to understand the various parameters that govern the reaction potential, selectivity, and the stability with well‐defined catalysts and try to extrapolate them to the pyrolyzed catalysts. In this chapter, we give an overview of the parameters that influence the catalysis of ORR with well‐defined ORR catalysts. These can later be used to further enhance the performance of the state‐of‐the‐art PGM‐free ORR catalysts.

Acoustic-directed assembly is a modular and flexible bottom-up technique with the potential to pattern a wide range of materials. Standing acoustic waves have been previously employed for patterning preformed metal particles, however, direct patterning of metallic structures from precursors remains unexplored. Here, we investigate utilization of standing waves to exert control over chemical reaction products, while also exploring their potential in the formation of multi-layered and composite micro-structures. Periodic metallic micro-structures were formed in a single step, simplifying microstructure fabrication. Concentric structures were obtained by introducing a metal precursor salt and a reducing agent into a cylindrical piezoelectric resonator that also served as a reservoir. In addition, we introduce an innovative approach to directly fabricate metallic multi-layer and composite structures by reducing different metal ions or adding nanoparticles during the reduction step. Fewer steps are needed, compared with other methods, and there is no need to stabilize the nanoparticles or to ensure chemical affinity between the metallic matrix and inorganic nanoparticles. This innovative approach is promising for production of complex microstructures with enhanced functionality and controlled properties.

Owing to high energy density and economic viability, rechargeable Mg-ion batteries (MIB) are considered as alternative to lithium-ion batteries. However, beside chevrel phase, none of conventional inorganic cathode materials demonstrate reversible intercalation/deintercalation of Mg+2 ions in anhydrous electrolyte system. The lack of high voltage and high-capacity cathode frustrates the realization of MIB. Previous studies indicated that vanadium pentoxide (V2O5) has potential to reversibly insert\extract Mg ions. However, many attempts to utilize V2O5 demonstrated limited electrochemical response, due to hindered Mg ion mobility in solid. Herein, we demonstrated a tailored approach to synthesize uniformly dispersed spherical V2O5 homogeneously coated with 2D VS2 through a facile in-situ chemical method and study the electrochemical activity in 0.2 M Mg(TFSI)2 + MgCl2 in DME electrolyte system and …

Atopic dermatitis (AD) is associated with dysregulated type 1 interferon (IFN)–mediated responses, in parallel with the dominant type 2 inflammation. However, the pathophysiology of this dysregulation is largely unknown. Adenosine-to-inosine (A-to-I) RNA editing plays a critical role in immune regulation by preventing double-stranded (ds) RNA recognition by MDA5 and IFN activation. We studied global A-to-I editing in AD in order to elucidate the role played by altered editing in the pathophysiology of this disease.Analysis of three RNA sequencing (RNA-seq) datasets of AD skin samples revealed reduced levels of A-to-I RNA editing in AD. This reduction was seen globally throughout Alu repeats, as well as in coding genes and in specific pre-mRNA loci expected to create long dsRNA, the main substrate of MDA5 leading to type I IFN activation. Consistently, IFN signature genes (ISG) were upregulated. In contrast …

The state‐of‐the‐art Platinum group metal (PGM)‐free oxygen reduction reaction (ORR) catalysts have been synthesized using the pyrolysis of iron, nitrogen, and carbon precursors, and result in highly active ORR catalysts, but their undefined structure limits their further development. Since the inspiration for these catalysts came from well‐defined structures of transition metal complexes, it is important to understand the various parameters that govern the reaction potential, selectivity, and the stability with well‐defined catalysts and try to extrapolate them to the pyrolyzed catalysts. In this chapter, we give an overview of the parameters that influence the catalysis of ORR with well‐defined ORR catalysts. These can later be used to further enhance the performance of the state‐of‐the‐art PGM‐free ORR catalysts.

Given the current status of coronavirus disease 2019 (COVID-19) as a global pandemic, it is of high priority to gain a deeper understanding of the disease's development and how the virus impacts its host. Adenosine (A)-to-Inosine (I) RNA editing is a post-transcriptional modification, catalyzed by the ADAR family of enzymes, that can be considered part of the inherent cellular defense mechanism as it affects the innate immune response in a complex manner. It was previously reported that various viruses could interact with the host's ADAR enzymes, resulting in epigenetic changes both to the virus and the host. Here, we analyze RNA-seq of nasopharyngeal swab specimens as well as whole-blood samples of COVID-19 infected individuals and show a significant elevation in the global RNA editing activity in COVID-19 compared to healthy controls. We also detect specific coding sites that exhibit higher editing …

The ability to control neuronal mobility and organization is of great importance in developing neuronal interfaces and novel therapeutic approaches. An emerging promising method is the manipulation of neuronal cells from afar via magnetic forces. Nevertheless, using magnetic iron oxide nanoparticles as internal actuators may lead to biotoxicity, adverse influence on intracellular processes, and thus requires prerequisite considerations for therapeutic approaches. Magnetizing the cells via the incorporation of magnetic particles that can be applied extracellularly is advantageous. Herein, we have developed a magnetic system based on streptavidin–biotin interaction to decorate cellular membrane with magnetic elements. In this model, superparamagnetic microparticles, coated with streptavidin, were specifically bound to biotinylated PC12 cells. We demonstrated that cell movement can be directed remotely by the forces produced by pre-designed magnetic fields. First, using time lapse imaging, we analyzed the kinetics of cell migration towards the higher flux zone. Next, to form organized networks of cells we designed and fabricated micro-patterned magnetic devices. The fabricated devices were composed of a variety of ferromagnetic shapes, sputter-deposited onto glass substrates. Cells that were conjugated to the magnetic particles were plated atop the micro-patterned substrates, attracted to the magnetic actuators and became fixed onto the magnetic patterns. In all, our study presents a novel system based on a well-known molecular technology combined with nanotechnology that may well lead to the expansion of implantable magnetic …

Base editing (BE) techniques offer efficient means to modify specific nucleotides in the genome. While current research mainly focuses on applying BE for treating genetic diseases caused by single-nucleotide variants (SNVs), its potential in cancer is worth exploring, as many tumors arise from an accumulation of various mutations. BE techniques primarily consist of a fusion between a Cas nuclease and a deaminase (Cas-BE), that enables A-to-G or C-to-T edits. This allows for the correction of G>A and T>C SNVs at the DNA or RNA level. Additionally, BE can correct C>T and A>G SNVs at the DNA level through the cellular DNA repair response. Precise targeting is aimed by a programmed guide RNA (gRNA), which engages in Watson-Crick base pairing with the desired region. However, a remaining concern is gRNA binding to additional locations in the genome, leading to unintended off-target edits. An …

The ability to control neuronal mobility and organization is of great importance in developing neuronal interfaces and novel therapeutic approaches. An emerging promising method is the manipulation of neuronal cells from afar via magnetic forces. Nevertheless, using magnetic iron oxide nanoparticles as internal actuators may lead to biotoxicity, adverse influence on intracellular processes, and thus requires prerequisite considerations for therapeutic approaches. Magnetizing the cells via the incorporation of magnetic particles that can be applied extracellularly is advantageous. Herein, we have developed a magnetic system based on streptavidin–biotin interaction to decorate cellular membrane with magnetic elements. In this model, superparamagnetic microparticles, coated with streptavidin, were specifically bound to biotinylated PC12 cells. We demonstrated that cell movement can be directed remotely by the forces produced by pre-designed magnetic fields. First, using time lapse imaging, we analyzed the kinetics of cell migration towards the higher flux zone. Next, to form organized networks of cells we designed and fabricated micro-patterned magnetic devices. The fabricated devices were composed of a variety of ferromagnetic shapes, sputter-deposited onto glass substrates. Cells that were conjugated to the magnetic particles were plated atop the micro-patterned substrates, attracted to the magnetic actuators and became fixed onto the magnetic patterns. In all, our study presents a novel system based on a well-known molecular technology combined with nanotechnology that may well lead to the expansion of implantable magnetic …

Recent studies have underscored the pivotal role of adenosine-to-inosine RNA editing, catalyzed by ADAR1, in suppressing innate immune interferon responses triggered by cellular double-stranded RNA (dsRNA). However, the specific ADAR1 editing targets crucial for this regulatory function remain elusive. We review analyses of transcriptome-wide ADAR1 editing patterns and their evolutionary dynamics, which offer valuable insights into this unresolved query. The growing appreciation of the significance of immunogenic dsRNAs and their editing in inflammatory and autoimmune diseases and cancer calls for a more comprehensive understanding of dsRNA immunogenicity, which may promote our understanding of these diseases and open doors to therapeutic avenues.

Iron–nitrogen–carbon (FeNC) catalysts are a viable alternative to platinum, but still lack the necessary performance. Now, pyrolysis under forming gas is found as a path to boosting their site density, activity and durability.

The ability to control neuronal mobility and organization is of great importance in developing neuronal interfaces and novel therapeutic approaches. An emerging promising method is the manipulation of neuronal cells from afar via magnetic forces. Nevertheless, using magnetic iron oxide nanoparticles as internal actuators may lead to biotoxicity, adverse influence on intracellular processes, and thus requires prerequisite considerations for therapeutic approaches. Magnetizing the cells via the incorporation of magnetic particles that can be applied extracellularly is advantageous. Herein, we have developed a magnetic system based on streptavidin–biotin interaction to decorate cellular membrane with magnetic elements. In this model, superparamagnetic microparticles, coated with streptavidin, were specifically bound to biotinylated PC12 cells. We demonstrated that cell movement can be directed remotely by the forces produced by pre-designed magnetic fields. First, using time lapse imaging, we analyzed the kinetics of cell migration towards the higher flux zone. Next, to form organized networks of cells we designed and fabricated micro-patterned magnetic devices. The fabricated devices were composed of a variety of ferromagnetic shapes, sputter-deposited onto glass substrates. Cells that were conjugated to the magnetic particles were plated atop the micro-patterned substrates, attracted to the magnetic actuators and became fixed onto the magnetic patterns. In all, our study presents a novel system based on a well-known molecular technology combined with nanotechnology that may well lead to the expansion of implantable magnetic …

Millions of adenosines are deaminated throughout the transcriptome by ADAR1 and/or ADAR2 at varying levels, raising the question of what are the determinants guiding substrate specificity and how these differ between the two enzymes. We monitor how secondary structure modulates ADAR2 vs ADAR1 substrate selectivity, on the basis of systematic probing of thousands of synthetic sequences transfected into cell lines expressing exclusively ADAR1 or ADAR2. Both enzymes induce symmetric, strand-specific editing, yet with distinct offsets with respect to structural disruptions: −26 nt for ADAR2 and −35 nt for ADAR1. We unravel the basis for these differences in offsets through mutants, domain-swaps, and ADAR homologs, and find it to be encoded by the differential RNA binding domain (RBD) architecture. Finally, we demonstrate that this offset-enhanced editing can allow an improved design of ADAR2 …

Forward Brillouin scattering fiber sensors can detect and analyze media outside the cladding of standard fibers, where guided light does not reach. Nearly all such sensors reported to-date have relied on the radially symmetric guided acoustic modes of the fiber. Wave motion in these modes is strictly dilatational. However, forward Brillouin scattering also takes place through torsional–radial guided acoustic modes of the fiber. Torsional–radial modes exhibit more complex tensor characteristics, and they consist of both dilatational and shear wave contributions. In this work, we show that forward Brillouin sensing through torsional–radial acoustic modes is qualitatively different from processes based on the radial ones. While dilatational wave components may dissipate toward liquids outside the fiber cladding, shear waves do not. Consequently, the effect of outside liquids varies among torsional–radial modes. Those …

The process of aging refers to physiological changes that occur to an organism as time progresses and involves changes to DNA, proteins, metabolism, cells, and organs. Like the rest of the cells in the body, gametes age, and it is well established that there is a decline in reproductive capabilities in females and males with aging. One of the major pathways known to be involved in aging is epigenetic changes. The epigenome is the multitude of chemical modifications performed on DNA and chromatin that affect the ability of chromatin to be transcribed. In this review, we explore the effects of aging on female and male gametes with a focus on the epigenetic changes that occur in gametes throughout aging. Quality decline in oocytes occurs at a relatively early age. Epigenetic changes constitute an important part of oocyte aging. DNA methylation is reduced with age, along with reduced expression of DNA …

Surface characterization is essential for understanding chemical and electrochemical transformations occurring on surfaces or at interfaces. Battery electrode aging processes, biofilm growth, crystallization, and transport/signaling across cellular membranes are only a few examples of such phenomena. This special issue delves into applied electrochemistry and nonlinear optical techniques applicable to surface characterization.