BINA

The G-and V-type nerve agents are among the most toxic compounds known, where inhalation of a few mg could cause potential death. Over the years wild-type phosphotriesterase (PTE) has gained much attention due to its capability of detoxifying these deadly compounds. The underlying mechanism proceeds via a hydroxyl attack on the P or C centers of the organophosphate nerve agents followed by the departure of the leaving group. Two Zn 2+ cations present in the active site center of PTE indirectly assist the hydrolysis. Apart from the wild-type PTE, several designer enzyme variants reportedly catalyze the hydrolysis process much more efficiently. Herein, we studied the hydrolysis of eight toxic compounds with one of the enzyme variants (PTE_27) that show higher efficiency than the wild type as reported in a recent article. We docked both the high energy intermediate state and substrate for all the eight …

Efimov states are exotic and counterintuitive three-body quantum states that emerge in the vicinity of two-atom Feshbach resonances. These states exhibit remarkable characteristics as their large spatial extent and extremely weak binding energies following an infinite geometric series, and exist even when interactions are not strong enough to bind two atoms. Efimov states are universal and produce observable effects at critical values of the interaction strength across the two-body resonance when approaching their threshold for dissociation into the different types of three-body continua. In particular, as the strength of the interaction is decreased, an Efimov state merges into the atom-dimer threshold and eventually dissociates into an unbound atom-dimer pair. Here we explore this critical point using refined coherent few-body spectroscopy in Li atoms near a narrow two-body Feshbach resonance. Contrary to the expectation set by universality, we find that the Li Efimov trimer does not immediately dissociate when passing the threshold, and survives as a metastable state embedded in the atom-dimer continuum. We identify this behavior with a novel phenomena related to the emergence of a repulsive interaction in the atom-dimer channel which reshapes the three-body interactions in systems characterized by narrow Feshbach resonances. Our results shed new light on the nature of Li Efimov states and provide a new path to understand various puzzling phenomena observed here, as well as in other previous experimental studies.

Broad area laser diodes are attractive for the high optical power they can produce. Unfortunately, this high power normally comes at the cost of severely reduced spatial coherence since the wide area of the diode wave-guide is inherently spatially multi-mode along the slow axis. We demonstrate a method to significantly improve the spatial coherence of a high-power broad-area diode by placing it in an external cavity that is mode selective. We design the cavity, such that the diode aperture acts as its own spatial filter, obviating the need for an intra-cavity slit-filter, and optimally utilizing the entire gain medium. We demonstrate this soft filtering method using wide diodes of and widths and compare its power-efficiency to the standard approach of hard-filtering with a slit. We obtain high-gain operation in a pure single-mode, demonstrating up to 1.5 W CW power at 1064 nm with excellent beam quality …

The purpose of the review is to provide new insight into the potential of surface modification of carbon fibers for enhancing the application of the carbon fibers many a fold. To this end a total of 429 papers on the subject of surface modication of carbon fibers by a variety of chemical and electrochemical methods published during the period from 2010-2022 have been reviewed. Astounding results of surface funcationalization of carbon fibers by a variety of state of the art methods resulting in the unconventional applications of the resulting modified carbon fibers are summarized in a nut-shell in schemes from 1-6 towards the end of the review. Surface modifica-tion induces functionality to carbon fibers (CFs). The vitality of CF surface modification reac-tions could only be compared to the life process of respiration that sustains the multi functional-ity of living cells. Applicability of CFs can be drastically enhanced in incomprehensible ways by surface modification. Upon surface modification, inert and non-reactive CF surface becomes chemically active and functional with utility in diverse fields, namely, health, energy, environ-ment, defense, catalysis, smart materials and many others. Surface modification methods can be broadly classified into chemical, electrochemical and physical methods. By these surface modi-fication methods, the inert FC surface becomes polar. Surface properties like roughness, wetta-bility and energy are enhanced. Modification processes like sizing, oxidation, amination, si-lanization, polymerization, nanoarchitecture induces multifunctionality on CF surface. Modi-fied CFs when used as reinforcing material in carbon fiber …

The short time (large energy) behavior of the Sachdev-Ye-Kitaev model (SYK) is one of the main motivation to the growing interest garnered by this model. True chaotic behaviour sets in at the Thouless time, which can be extracted from the energy spectrum. In order to do so, it is necessary to unfold the spectrum, i.e., to filter out global tendencies. Using a simple ensemble average for unfolding results in a parametically low estimation of the Thouless energy. By examining the behavior of the spectrum as the distribution of the matrix elements is changed into a log-normal distribution it is shown that the sample to sample level spacing variance determines this estimation of the Thouless energy. Using the singular value decomposition method, SVD, which filters out these sample to sample fluctuations, the Thouless energy becomes parametrically much larger, essentially of order of the band width. It is shown that the SYK model in non-self-averaging even in the thermodynamic limit which must be taken into account in considering its short time properties.

Chemical pollutants in drinking water can have many sources, such as pharmaceutical waste, agricultural runoff, and industrial discharges1, 2, 3. The development of a reliable, sensitive, and handheld sensor for the detection of a mixture of contaminants is important, both for human health and the environment. Herein, we show the development of a plasmonic sensor for Surface-enhanced Raman spectroscopy (SERS) and colorimetry measurements. Two types of plasmonic surfaces which enhance the electromagnetic field are presented here;(i) Well-defined cavities milled in silver substrates which are covered with 5 nm of SiO2 for stability.(ii) A scalable metallic-like aerogel network with large surface area, for increasing the sensitivity of our measurements. Three different families of analytes were studied, which can be found in drinking water: Piperidine and its derivatives (Pharmaceutical waste), Dioxins & Polychlorinated biphenyls, Per-and polyfluoroalkyl substances, each of which is toxic, both to the environment and humans health, even at a low concentration of 30 mg/Kg (3* 10-4M). Those

Broad area laser diodes are attractive for the high optical power they can produce. Unfortunately, this high power normally comes at the cost of severely reduced spatial coherence since the wide area of the diode wave-guide is inherently spatially multi-mode along the slow axis. We demonstrate a method to significantly improve the spatial coherence of a high-power broad-area diode by placing it in an external cavity that is mode selective. We design the cavity, such that the diode aperture acts as its own spatial filter, obviating the need for an intra-cavity slit-filter, and optimally utilizing the entire gain medium. We demonstrate this soft filtering method using wide diodes of and widths and compare its power-efficiency to the standard approach of hard-filtering with a slit. We obtain high-gain operation in a pure single-mode, demonstrating up to 1.5 W CW power at 1064 nm with excellent beam quality …

Contamination in water can occur through natural processes, such as leaching of minerals from soil, or through industrial waste. It is needless to mention that it has serious impacts of human health, as well as on the environment. Hence, the development of analytical sensors to detect those contaminations is highly important.We developed a facile method for fabrication of aerogel-like metallic networks. Our method is based on physical vapor deposition (PVD) onto a charged substrate. The resulting aerogel-like metallic network contains a 3D carpet of ‘hot-spots’ at a broad range of optical regime, and, thus, leads to enhancement of the electro-magnetic (EM) field and optical processes. As a result of the strong, broadband, and deep sub-wavelength confinement of the EM field, inherently weak nonlinear optical processes, such as Raman scattering, can be boosted by orders of magnitude by this metallic network interface. Herein, we present aerogel-like metallic networks for optical sensing of contaminates in water. In addition, we show its application as a photocatalytic 3D structure.

Recent research on two-dimensional (2D) transition metal dichalcogenides (TMDCs) has led to remarkable discoveries of fundamental phenomena and to device applications with technological potential. Large-scale TMDCs grown by chemical vapor deposition (CVD) are now available at continuously improving quality, but native defects and natural degradation in these materials still present significant challenges. Spectral hysteresis in gate-biased photoluminescence (PL) measurements of WSe2 further revealed long-term trapping issues of charge carriers in intrinsic defect states. To address these issues, we apply here a two-step treatment with organic molecules, demonstrating the “healing” of native defects in CVD-grown WSe2 and WS2 by substituting atomic sulfur into chalcogen vacancies. We uncover that the adsorption of thiols provides only partial defect passivation, even for high adsorption quality, and …

Nanoporous gold (Au) films are self-supported structures that possess a large surface area and extraordinary catalytic activity. Generally, nanoporous gold is obtained by solution-based dealloying where the less noble metal, often silver (Ag), is etched out. However, the residual amounts of the sacrificial metal are not well controlled, the impure samples show restructuring, and the residual metal prevents the study of the catalytic role of Au alone. Here, we fabricate impurity-free nanoporous gold films by a plasma-enabled dry synthetic route. The scheme does not include sacrificial metals or solution processing and is much more general. It is used to obtain self-supported ultra-pure nanoporous gold films with controllable pore sizes. The impurity-free nanoporous gold films possess highly curved ligaments, are remarkably robust, and stable over hundreds of electrochemical cycles. Furthermore, they contain many …

The transition from dissolution-precipitation to quasi-solid-state sulfur reaction promises restricted polysulfide shuttle and lean electrolyte operation of Li-S batteries but incurs poor reaction kinetics. We here demonstrate that structural reorganization of sparingly solvating electrolytes (SSEs)—which is uniquely afforded by using low-density and low-cost aromatic anti-solvents—is vital for taming the quasi-solid-state sulfur reaction. Aromatic anti-solvents disrupt the interconnected structure of concentrated tetrahydrofuran (THF) electrolyte, uniquely creating subdomains that act to dissolve elemental sulfur, thus accelerating its consumption and re-formation while maintaining ultralow polysulfides solubility. The altered subdomains further result in robust solid electrolyte interphase (SEI) on lithium metal. As a result, the Li-S cell with a 3 mgsulfur cm−2 sulfur cathode can cycle steadily for ∼160 cycles with a lean …

Chemical pollutants in drinking water can have many sources, such as pharmaceutical waste, agricultural runoff, and industrial discharges1, 2, 3. The development of a reliable, sensitive, and handheld sensor for the detection of a mixture of contaminants is important, both for human health and the environment. Herein, we show the development of a plasmonic sensor for Surface-enhanced Raman spectroscopy (SERS) and colorimetry measurements. Two types of plasmonic surfaces which enhance the electromagnetic field are presented here;(i) Well-defined cavities milled in silver substrates which are covered with 5 nm of SiO2 for stability.(ii) A scalable metallic-like aerogel network with large surface area, for increasing the sensitivity of our measurements. Three different families of analytes were studied, which can be found in drinking water: Piperidine and its derivatives (Pharmaceutical waste), Dioxins & Polychlorinated biphenyls, Per-and polyfluoroalkyl substances, each of which is toxic, both to the environment and humans health, even at a low concentration of 30 mg/Kg (3* 10-4M). Those

SignificanceDiabetes is a prevalent disease worldwide that can cause severe health problems. Accurate blood glucose detection is crucial for diabetes management, and noninvasive methods can be more convenient and less painful than traditional finger-prick methods.AimWe aim to report a noncontact speckle-based blood glucose measurement system that utilizes artificial intelligence (AI) data processing to improve glucose detection accuracy. The study also explores the influence of an alternating current (AC) induced magnetic field on the sensitivity and selectivity of blood glucose detection.ApproachThe proposed blood glucose sensor consists of a digital camera, an AC-generated magnetic field source, a laser illuminating the subject’s finger, and a computer. A magnetic field is applied to the finger, and a camera records the speckle patterns generated by the laser light reflected from the finger. The acquired …

Significance: Diabetes is a prevalent disease worldwide that can cause severe health problems. Accurate blood glucose detection is crucial for diabetes management, and noninvasive methods can be more convenient and less painful than traditional finger-prick methods.Aim: We aim to report a noncontact speckle-based blood glucose measurement system that utilizes artificial intelligence (AI) data processing to improve glucose detection accuracy. The study also explores the influence of an alternating current (AC) induced magnetic field on the sensitivity and selectivity of blood glucose detection.Approach: The proposed blood glucose sensor consists of a digital camera, an AC-generated magnetic field source, a laser illuminating the subject’s finger, and a computer. A magnetic field is applied to the finger, and a camera records the speckle patterns generated by the laser light reflected from the finger. The …

Topological insulators (TIs) are a class of materials characterized by an insulting bulk and high mobility topologically protected surface states, making them promising candidates for future optoelectronic and quantum devices. Although their electronic and transport properties have been extensively studied, their optical properties and prospective photonic capabilities have not been fully uncovered. Here, we use a combination of far-field and near-field nanoscale imaging and spectroscopy, to study CVD grown Bi2Se3 nanobeams (NBs). We first extract the mid-infrared (MIR) optical constants of Bi2Se3, revealing refractive index values as high as n ~6.4, and demonstrate that the NBs support Mie-resonances across the MIR. Local near-field reflection phase mapping reveals domains of various phase shifts, providing information on the local optical properties of the NBs. We experimentally measure up to 2{\pi} phase-shift across the resonance, in excellent agreement with FDTD simulations. This work highlights the potential of TI Bi2Se3 for quantum circuitry, non-linear generation, high-Q metaphotonics, and IR photodetection.

Na‐ion batteries have recently emerged as a promising alternative to Li‐based batteries, driven by an ever‐growing demand for electricity storage systems. In the present work, we propose a cobalt‐free high‐capacity cathode for Na‐ion batteries, synthesized using a high‐entropy approach. The high‐entropy approach entails mixing more than five elements in a single phase; hence, obtaining the desired properties is a challenge since this involves the interplay between different elements. Here, instead of oxide, oxyfluoride is chosen to suppress oxygen loss during long‐term cycling. Supplement to this, Li was introduced in the composition to obtain high configurational entropy and Na vacant sites, thus stabilizing the crystal structure, accelerating the kinetics of intercalation/deintercalation, and improving the air stability of the material. With the optimization of the cathode composition, a reversible capacity of 109 …

In this work, we demonstrate the focusing of a Gaussian laser beam, in silicon, by a vortex-shaped beam where both beams are at a wavelength of 775nm, which can sharpen the beam's PSF to improve the resolution in laser scanning microscopy.

BACKGROUND Glioblastoma (GBM), is the most common primary brain tumor. GBM contains a small subpopulation of glioma stem cells (GSCs) that are implicated in tumor recurrence and treatment resistance and therefore represent important therapeutic targets. Recent clinical studies suggest propofol impacts subsequent tumor response to treatments and patient prognosis. The effects of propofol on patient derived GSCs alone and in combination with radiation and temozolomide, (TMZ) have not been reported. Objectives: The molecular mechanisms underlying propofol’s anti-tumor effects on GSCs and its effect on cellular communication with microglia was studied. Using GSC spheroids, differentiated glioma and tumor cells on a microfluid chip, effects of propofol alone and together with radiation and TMZ on the self-renewal and stemness of GSCs, their mesenchymal transit and the …

The exploration of cathode and anode materials that enable reversible storage of mono and multivalent cations has driven extensive research on organic compounds. In this regard, polyimide (PI)‐based electrodes have emerged as a promising avenue for the development of post‐lithium energy storage systems. This review article provides a comprehensive summary of the synthesis, characterization, and application of PI compounds as electrode materials capable of hosting a wide range of cations. Furthermore, the review also delves into the advancements in PI‐based separators and their effectiveness as polymeric binders. By highlighting the key findings in these areas, this review aims to contribute to the understanding and advancement of PI‐based structures paving the way for the next generation of energy storage systems.

In this paper, we present a remote optical method for sound detection using rolling shutter (RS) and speckle analysis. Findings show the ability to remotely monitor the high frequency using low framerate camera.

I will present a photonic sensor that can be used for remote sensing of many biomedical parameters simultaneously and continuously. The technology is based upon illuminating a surface with a laser and then using an imaging camera to perform temporal and spatial tracking of secondary speckle patterns in order to have nano metric accurate estimation of the movement of the back reflecting surface. The capability of sensing those movements in nano-metric precision allows connecting the movement with remote bio-sensing and with medical diagnosis capabilities. The proposed technology was already applied for remote and continuous estimation of vital bio-signs (such as heart beats, respiration, blood pulse pressure and intra ocular pressure), for molecular sensing of chemicals in the blood stream (such as for estimation of alcohol, glucose and lactate concentrations in blood stream, blood coagulation and …