BINA

The COVID-19 pandemic has emphasized the inability of diagnostic laboratories' testing capacity to keep up with the surging demand. The primary reasons were the lack of reagents (e.g., viral transport media and nucleic acid extraction kits) and the low throughput of the gold-standard molecular detection method (RT-qPCR). While the reagent shortages were eventually resolved, the limited throughput of the RT-qPCR remains a bottleneck for high-throughput testing applications even today. Here, we introduce a rapid saliva-based extraction-free molecular assay, which utilizes a non-invasive saliva sampling and extraction-free sample preparation, a fast endpoint RT-PCR and a high-throughput optical modulation biosensing (ht-OMBi) detection platform. We blindly tested 364 paired nasopharyngeal swabs and saliva samples from suspected SARS-CoV-2 cases in Israel. Compared with the gold standard swab …

G54. 00011: Light chaotic dynamics and ray engineering transformed from curved to flat space

Fluorescence-based imaging is a powerful tool for studying biological systems, but its application in vivo is hindered by tissue scattering and autofluorescence. To enhance the usefulness of non-invasive in vivo fluorescence imaging, a comprehensive understanding of these factors is crucial. This presentation introduces a diffusion model that represents a fluorophore within tissue, verified using Monte Carlo simulations and experimental measurements with tissue-like phantom slabs of varying reduced scattering coefficients and thicknesses. The study reveals a correlation between fluorescence intensity (FI) and thickness, confirming the expected decay. Surprisingly, the exponential decay rate decreases with increasing scattering coefficient, contradicting intuition. This counterintuitive finding suggests that highly scattering media result in weaker FI decay dependence on tissue depth, reducing fluorescence artifacts …

The effect of doping concentration on the temperature performance of the novel split-well resonant-phonon (SWRP) terahertz quantum-cascade laser (THz QCL) scheme supporting a clean 4-level system design was analyzed using non-equilibrium Green’s functions (NEGF) calculations. Experimental research showed that increasing the doping concentration in these designs led to better results compared to the split-well direct-phonon (SWDP) design, which has a larger overlap between its active laser states and the doping profile. However, further improvement in the temperature performance was expected, which led us to assume there was an increased gain and line broadening when increasing the doping concentration despite the reduced overlap between the doped region and the active laser states. Through simulations based on NEGF calculations we were able to study the contribution of the different …

The effect of doping concentration on the temperature performance of the novel split-well resonant-phonon (SWRP) terahertz quantum-cascade laser (THz QCL) scheme supporting a clean 4-level system design was analyzed using non-equilibrium Green’s functions (NEGF) calculations. Experimental research showed that increasing the doping concentration in these designs led to better results compared to the split-well direct-phonon (SWDP) design, which has a larger overlap between its active laser states and the doping profile. However, further improvement in the temperature performance was expected, which led us to assume there was an increased gain and line broadening when increasing the doping concentration despite the reduced overlap between the doped region and the active laser states. Through simulations based on NEGF calculations we were able to study the contribution of the different …

In this presentation we will present an all-optical pump-probe approach for non-contact photo-acoustic sensing and imaging. We will show various configurations for enhancing the obtainable spatial and temporal resolution as well as usage of the proposed sensing technique for various important applications. The presented pump-probe approach allows localized and direct technique for performing photoacoustic imaging while the focused pump beam excites the acoustic signal, and a focused probe beam does the spatial-temporal analysis of the diffracted speckle patterns. This analysis is done in one configuration by analyzing time changing contrast of the time varying speckle patterns and in another sensing configuration, where the speckle pattern do not vary but rather laterally move, by tracking the position of the correlation peak. Due to its advantage of performing localized photo-acoustic sensing, the …

In previous work, we introduced an elegant approach for bromide recovery from water by the introduction of a hybrid physical adsorption and capacitive deionization processes for selective removal and recovery of boron from water. In this paper, we show that the harsh environment of water contaminated with bromine-moieties adversely affects the longevity of relevant electrodes, with close to 100 consecutive work hours of bromides removal without noticeable degradation. To extend the lifespan of electrodes, we used an asymmetric CDI cell with a 1:5 positive/negative electrodes ratio in which a polarity switch between electrodes is applied every six adsorption-desorption cycles in a way that in each adsorption-desorption cycle, a different electrode of the six electrodes, functions as the positive electrode. We deduce that the polarity switch reduces oxidation and subsequent degradation of the positive electrodes …

BACKGROUND Myocardial infarction (MI) and heart failure are associated with an increased incidence of cancer. However, the mechanism is complex and unclear. Here, we aimed to test our hypothesis that cardiac small extracellular vesicles (sEVs), particularly cardiac mesenchymal stromal cell–derived sEVs (cMSC-sEVs), contribute to the link between post-MI left ventricular dysfunction (LVD) and cancer. METHODS We purified and characterized sEVs from post-MI hearts and cultured cMSCs. Then, we analyzed cMSC-EV cargo and proneoplastic effects on several lines of cancer cells, macrophages, and endothelial cells. Next, we modeled heterotopic and orthotopic lung and breast cancer tumors in mice with post-MI LVD. We transferred cMSC-sEVs to assess sEV biodistribution and its effect on tumor growth. Finally, we tested the effects of sEV depletion and spironolactone treatment on cMSC-EV release …

Nanophotonic techniques for diagnosis of a physiological tissue state are useful due to their noninvasive nature. Yet, light reflectance from a tissue is determined by the medium optical properties, absorption and scattering. Therefore, evaluating physiological parameters that correlate with absorption exclusively requires calibration of the scattering. While finding pulse rate is possible in a single wavelength, other parameters, such as oxygen saturation, require more than one light source and ratiometric measurements. As a result, the differences in the optical pathlength of the different wavelengths produce an inherent error. We have previously discovered the iso-path length (IPL) point, a specific position around a cylindrical media where the light intensity is not affected by the scattering. It was found by measuring the full scattering profile (FSP), meaning the angular distribution of light intensity of cylindrical tissues …

One of interesting phenomena of a black hole (BH) in its vicinity due to its extreme curvature of spacetime is called a photon sphere (PS), a closed trajectory where photons get trapped and orbit. In this work, we design novel 3D microcavities and investigate lasing on modes localized on a PS, induced by attractive nature of BH. We explore these eigenmodes by conformally transforming a Schwarzschild BH metric into a 2D plane with varying refractive index. We analytically confirm the existence of PS modes by extending our previous theory of conformal transformations [PNAS 119, e2112052119 (2022)] into open systems, and solving the wave equation under a WKB framework. To numerically induce lasing of PS modes, we selectively pump the 2D cavity above the vicinity of the PS. The lasing process is revealed by a 3D finite-difference time-domain simulation coupled to the atomic population of a four-level …

Identifying the type of structural defects and determining their concentration is crucial for effective defect engineering strategies since they govern various physical, chemical, and optoelectronic properties of graphene. Here, we study the effects of Ga ion irradiation on freestanding monolayer graphene, specifically focusing on the behavior of three defect-induced Raman lines (D, D' and (D+ D')). By employing a modified approach of the local activation model, we determine the key defect parameters of each line and show their dependence on different vibrational configurations of the iTO and iLO phonons emitted during scattering. The redshift of the lines and the broadening of their width, observed with an increase in the concentration of radiation defects over Nd ≈ 1013cm−2, are explained by the tensile stress of the graphene film and a decrease in the phonon lifetime, respectively. The resulting intensity ratio I(D)/I …

Quantum interferometers represent a powerful class of devices that exploit the principles of quantum mechanics to achieve highly sensitive measurements and precise detection capabilities. In classical interferometry, light waves or matter waves combine and interfere, resulting in constructive or destructive interference patterns that encode information about the system being studied. In the quantum realm, interferometers leverage the unique properties of quantum states, such as superposition and entanglement, to surpass the sensitivity limits imposed by classical physics. We developed a new class of quantum interferometers, namely, the temporal SU(1,1) interferometer. Here, we present the code for numerically comparing classical SU(2) interferometer, regular quantum SU(1,1) interferometer, and our temporal SU(1,1) interferometer.

Control over the optical properties of atomically thin two-dimensional (2D) layers, including those of transition metal dichalcogenides (TMDs), is needed for future optoelectronic applications. Here, the near-field coupling between TMDs and graphene/graphite is used to engineer the exciton line shape and charge state. Fano-like asymmetric spectral features are produced in WS2, MoSe2, and WSe2 van der Waals heterostructures combined with graphene, graphite, or jointly with hexagonal boron nitride (h-BN) as supporting or encapsulating layers. Furthermore, trion emission is suppressed in h-BN encapsulated WSe2/graphene with a neutral exciton red shift (44 meV) and binding energy reduction (30 meV). The response of these systems to electron beam and light probes is well-described in terms of 2D optical conductivities of the involved materials. Beyond fundamental insights into the interaction of TMD …

Light-induced modification of material properties has garnered widespread interest within the scientific community. In fact, several effects can be potentially modified or enhanced when light interacts strongly with matter. As an alternative to ultrafast pump-probe experiments, cavity-mediated light-matter interaction offers the possibility to tailor the steady-state behavior of a material system by designing on-purpose electromagnetic environments.

Rapid, highly sensitive, and high-throughput detection of biomarkers at low concentrations is invaluable for the early diagnosis of various diseases. In many sensitive immunoassays, the protocol is time-consuming and requires a complicated and expensive detection system. Previously, we presented a high-throughput optical modulation biosensing (ht-OMB) system, which enables reading a 96-well plate within 10 minutes. In ht-OMB, to aggregate and immobilize the magnetic beads to one spot, a single cylindrical permanent magnet with a sharp tip is positioned under a 96-well plate. To reduce washing and separation steps, the laser beam is manipulated relative to the fixed magnetic beads. Recently, MagBiosense Inc., which commercializes the ht-OMB technology, provided us with a fully automated OMBi detection system. Here, we show the use of the OMBi system for highly sensitive serological (clinical anti …

Visualizing the current distribution in materials is a powerful tool to investigate and understand unconventional transport they exhibit. In the present work, we study a few microns thick devices of the layered chalcogenide material 1T-TaS 2. Pulsed DC excitation of the commensurate charge density wave (CCDW) phase in the system leads to a controllable, non-volatile, resistance-switching states. We use scanning SQUID microscopy to image, in-situ, the local current density map by mapping the field generated by the current flow. The images reveal the presence of electrical domains in the device and their effect on the current flow.

The unexpected discovery of superconductivity in magic angle twisted bilayer graphene immediately generated a wave of intense theoretical and experimental research attracted by its rich phase diagram, which seemingly resembles ones of copper-oxide high-temperature superconductors. Originated in the low-energy narrow electronic bands, a family of magic angle graphene compounds hosts a collection of exotic phases including but not limited to superconductivity, correlated insulators, topological and magnetic orders. Compared to other strongly-correlated systems, 2D multilayers offer a unique opportunity to tune the charge carrier density in situ and adjust system properties in other ways (for example, by alternating the distance to the gate or varying the dielectric environment), thus offering a potentially faster progress in understanding the underlying microscopic mechanisms governing its strong correlations …

Summary Knowledge of immunoglobulin and T cell receptor encoding genes is derived from high-quality genomic sequencing. High throughput sequencing is delivering large volumes of data, and precise, high-throughput approaches to annotation are needed. Digger is an automated tool that identifies coding and regulatory regions of these genes, with results comparable to those obtained by current expert curational methods. Availability and Implementation Digger is published under open source licence at https://github.com/williamdlees/Digger and is available as a Python package and a Docker container.

In today's medical world, endoscopy is one of the most common methods for assessing a patient's health status, yet in most cases, endoscopy is not sufficient and usually requires other examinations as well. It is widely known that healthy, and diseased tissues possess different optical properties like scattering and absorption. By finding the changes in those optical properties it's possible to determine the tissue status by endoscopy only. This poster suggests an alternative self-calibrated endoscopy examination for finding these properties and quantitatively assessing the tissue. Implementing the physical phenomenon called the iso pathlength (IPL) point, makes it possible to extract the tissue absorption property since it simplifies the problem into an easily solvable first-order problem. The phenomenon claims the existence of physical positions on the surface tissue, in which the light reflected from, isn't affected by the …

Male development in mammals depends on the activity of the two SOX gene: Sry and Sox9, in the embryonic testis. As deletion of Enhancer 13 (Enh13) of the Sox9 gene results in XY male-to-female sex reversal, we explored the critical elements necessary for its function and hence, for testis and male development. Here, we demonstrate that while microdeletions of individual transcription factor binding sites (TFBS) in Enh13 lead to normal testicular development, combined microdeletions of just two SRY/SOX binding motifs can alone fully abolish Enh13 activity leading to XY male-to-female sex reversal. This suggests that for proper male development to occur, these few nucleotides of non-coding DNA must be intact. Interestingly, we show that depending on the nature of these TFBS mutations, dramatically different phenotypic outcomes can occur, providing a molecular explanation for the distinct clinical …

Efimov trimers are exotic three-body quantum states that emerge from the different types of three-body continua in the vicinity of two-atom Feshbach resonances. In particular, as the strength of the interaction is decreased to a critical point, an Efimov state merges into the atom-dimer threshold and eventually dissociates into an unbound atom-dimer pair. Here we explore the Efimov state in the vicinity of this critical point using coherent few-body spectroscopy in 7Li atoms using a narrow two-body Feshbach resonance. Contrary to the expectation, we find that the 7Li 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 universal phenomenon related to the emergence of a repulsive interaction in the atom-dimer channel which reshapes the three-body interactions in any system …