BINA

Traumatic brain injury (TBI), which is characterized by damage to the brain resulting from a sudden traumatic event, is a major cause of death and disability worldwide. It has short- and long-term effects, including neuroinflammation, cognitive deficits, and depression. TBI consists of multiple steps that may sometimes have opposing effects or mechanisms, making it challenging to investigate and translate new knowledge into effective therapies. In order to better understand and address the underlying mechanisms of TBI, we have developed an in vitro platform that allows dynamic simulation of TBI conditions by applying external magnetic forces to induce acceleration and deceleration injury, which is often observed in human TBI. Endothelial and neuron-like cells were successfully grown on magnetic gels and applied to the platform. Both cell types showed an instant response to the TBI model, but the endothelial cells …

Neuroblastoma is a lethal childhood solid tumor of developing peripheral nerves. Two percent of children with neuroblastoma develop opsoclonus myoclonus ataxia syndrome (OMAS), a paraneoplastic disease characterized by cerebellar and brainstem-directed autoimmunity but typically with outstanding cancer-related outcomes. We compared tumor transcriptomes and tumor-infiltrating T and B cell repertoires from 38 OMAS subjects with neuroblastoma to 26 non-OMAS-associated neuroblastomas. We found greater B and T cell infiltration in OMAS-associated tumors compared to controls and showed that both were polyclonal expansions. Tertiary lymphoid structures (TLSs) were enriched in OMAS-associated tumors. We identified significant enrichment of the major histocompatibility complex (MHC) class II allele HLA-DOB∗01:01 in OMAS patients. OMAS severity scores were associated with the expression of …

Thermal effects are well known to influence the electronic and optical properties of materials through several physical mechanisms and are the basis for various optoelectronic devices. The thermo-optic (TO) effect, the refractive index variation with temperature (dn/dT), is one of the most common mechanisms used for tunable optical devices, including integrated optical components, metasurfaces, and nano-antennas. However, when a static and fixed operation is required, i.e., temperature invariant performance – this effect becomes a drawback and may lead to undesirable behavior through drifting of the resonance frequency, amplitude, or phase, as the operating temperature varies over time. In this work, we present a systematic approach to mitigate thermally induced optical fluctuations in nanophotonic devices. By using hybrid subwavelength resonators composed from two materials with opposite TO dispersions …

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 …

BackgroundTissue-integrated micro-electronic devices for neural stimulation hold great potential in restoring the functionality of degenerated organs, specifically, retinal prostheses, which are aimed at vision restoration. The fabrication process of 3D polymer-metal devices with high resolution and a high aspect-ratio (AR) is very complex and faces many challenges that impair its functionality.ApproachHere we describe the optimization of the fabrication process of a bio-functionalized 3D high-resolution 1mm circular subretinal implant composed of SU-8 polymer integrated with dense gold microelectrodes (23μm pitch) passivated with 3D micro-well-like structures (20μm diameter, 3μm resolution). The main challenges were overcome by step-by-step planning and optimization while utilizing a two-step bi-layer lift-off process; bio-functionalization was carried out by N2 plasma treatment and the addition of a bio …

Hydrogels have a significant impact on the fields of biological study and medical diagnosis. They are becoming more useful in bioanalytical and biosensing applications. The intriguing new nanomaterials quantum dots-hydrogel composites have gained a lot of interest because of their unmatched biocompatibility and tolerable biodegradability, which opens up a wide range of possible applications. Focusing on synthesis techniques, this review describes current developments in quantum dots-hydrogel composites, such as hydrogel gelation in quantum dots (QDs) solution, inserting prepared QDs into hydrogels after gelation, generating QDs in situ inside the preformed gel, and cross-linking through QDs. Biomedical applications such as bioimaging and biosensing are specifically examined, and then the inherent problems of design optimisation, biocompatibility, and bimodal applications, as well as the potential of …

Flexible sensors are important for applications, such as wearable medical devices, soft robotics, and more, as they can easily conform to soft and irregularly shaped surfaces. This study presents elliptical planar Hall effect magnetic sensors fabricated on a polyamide tape with an equivalent magnetic noise (EMN) better than 200 pT/Hz⁠. The sensor is characterized in flat and bent states with a bent radius of 10 mm. An EMN of 200 and 400 pT/Hz in flat and bent states, respectively, is achieved at a frequency of 100 Hz. The remarkable EMN combined with a simple, low-cost fabrication process makes these sensors a promising candidate for flexible electronics.

In nanophotonics, small mode volumes, high‐quality factor resonances, and large field enhancements without metals fundamentally scale with the refractive index and are key for many implementations involving light‐matter interactions. Topological insulators (TIs) are a class of insulating materials that host topologically protected surface states, some of which exhibit extraordinarily high permittivity values. Here, the optical properties of TI bismuth telluride (Bi2Te3) single crystals are studied. It is found that both the bulk and surface states contribute to the extremely large optical constants, with the real part of the refractive index peaking at n ≈ 11. Utilizing these ultra‐high index values, it is demonstrated that Bi2Te3 metasurfaces are capable of squeezing light in deep‐subwavelength structures, with the fundamental magnetic dipole (MD) resonance confined in unit cell sizes smaller than λ/10. It is further shown that …

Permselectivity of a membrane is central for the development of electrochemical energy storage devices with two redox couples, such as redox flow batteries (RFBs). In RFBs, Br3−/Br− couple is often used as a catholyte which can cross over to the anolyte, limiting the battery’s lifetime. Naturally, the development of permselective membranes is essential to the success of RFBs since state-of-the-art perfluorosulfonic acid (PFSA) is too costly. This study investigates membranes of graphene oxide (GO), polyvinylpyrrolidone (PVP), and imidazole (Im) as binder and linker, respectively. The GO membranes are compared to a standard PFSA membrane in terms of ionic conductivity (Na+) and permselectivity (exclusion of Br−). The ionic conduction is evaluated from electrochemical impedance spectroscopy and the permselectivity from two-compartment diffusion cells in a four-electrode system. Our findings suggest that the GO membranes reach conductivity and permselectivity comparable with standard PFSA membranes.

The intestinal epithelial barrier facilitates homeostatic host–microbiota interactions and immunological tolerance. However, mechanistic dissections of barrier dynamics following luminal stimulation pose a substantial challenge. Here, we describe an ex vivo intestinal permeability assay, X-IPA, for quantitative analysis of gut permeability dynamics at the whole-tissue level. We demonstrate that specific gut microbes and metabolites induce rapid, dose-dependent increases to gut permeability, thus providing a powerful approach for precise investigation of barrier functions.

The temperature-dependence of the chirality-induced spin selectivity (CISS) effect can be used to discriminate between different theoretical proposals for the mechanism of the CISS effect. Here, we briefly review key experimental results and discuss the effect of temperature in different models for the CISS effect. We then focus on the recently suggested spinterface mechanism and describe the different possible effects temperature can have within this model. Finally, we analyze in detail recent experimental results presented in the work of Qian et al.[Nature 606, 902–908 (2022)] and demonstrate that, contrary to the original interpretation by the authors, these data actually indicate that the CISS effect increases with decreasing temperature. Finally, we show how the spinterface model can accurately reproduce these experimental results.

Intracellular monitoring of pH and polarity is crucial for understanding cellular processes and functions. This study employed pH- and polarity-sensitive nanomaterials such as carbon dots (CDs) for the intracellular sensing of pH, polarity, and viscosity using integrated time-resolved fluorescence anisotropy (FA) imaging (TR-FAIM) and fluorescence lifetime (FLT) imaging microscopy (FLIM), thereby enabling comprehensive characterization. The functional groups on the surface of CDs exhibit sensitivity to changes in the microenvironment, leading to variations in fluorescence intensity (FI) and FLT according to pH and polarity. The FLT of CDs in aqueous solution changed gradually from 6.38 ± 0.05 ns to 8.03 ± 0.21 ns within a pH range of 2–8. Interestingly, a complex relationship of FI and FLT was observed during measurements of CDs with decreasing polarity. However, the FA and rotational correlation time (θ) increased from 0.062 ± 0.019 to 0.112 ± 0.023 and from 0.49 ± 0.03 ns to 2.01 ± 0.27 ns, respectively. This increase in FA and θ was attributed to the higher viscosity accompanying the decrease in polarity. Furthermore, CDs were found to bind to three locations in Escherichia coli: the cell wall, inner membrane, and cytoplasm, enabling intracellular characterization using FI and FA decay imaging. FLT provided insights into cytoplasmic pH (7.67 ± 0.48), which agreed with previous works, as well as the decrease in polarity in the cell wall and inner membrane. The CD aggregation was suspected in certain areas based on FA, and the θ provided information on cytoplasmic heterogeneity due to the aggregation and/or interactions with …

Three-dimensional porous nanostructured materials are considered superior materials for energy storage applications due to their high storage capability. A nickel copper-cobalt oxide (NCC) composite with a uniform 3-D porous nanostructure (positive electrode materials) and luffa sponge-derived activated carbon (LPAC) with honeycomb-like structure (negative electrode materials) were synthesized by a simple hydrothermal and chemical method. A sample of the nickel-copper cobalt oxide-5 (NCC-5) nanocomposite reached a high specific capacitance of 1048 F/g at the current density of 0.5 A/g. The NCC-5 nanocomposite sample shows a retention capacity of 93 % after 10,000 charge and discharge cycles with 95 % of Coulombic efficiency (CE). The LPAC illustrates a remarkable specific capacitance of 909 F/g at 1 A/g of current density, compared to the best literature value of 400 F/g. The full-cell NCC-5//LPAC …

This special issue is dedicated to the memory of Shimon Vega (1943–2021) with contributions from former students, postdocs, and other close colleagues. Shimon had seminal contributions in magnetic resonance, including in the areas of nuclear quadrupole resonance (NQR), solid-state NMR, and dynamic nuclear polarization (DNP). While dedicating a major effort to the development of NMR theory, he always made direct connections to experiments and relevant applications and was a gifted educator and teacher. The content of this special issue is a manifestation of these various facets in his personality.Matysik highlights, in his paper, the educational spirit of Shimon by describing the “Vega diagrams”; block representations of Hamiltonians and density matrices with pathways directing the reader to the relevant physics. On the theoretical side, the work of Sajith et al. extracts effective Hamiltonians and key …

Entanglement is a uniquely quantum resource giving rise to many quantum technologies. It is therefore important to detect and characterize entangled states, but this is known to be a challenging task, especially for multipartite mixed states. The correlation minor norm (CMN) was recently suggested as a bi-partite entanglement detector employing bounds on the quantum correlation matrix. In this paper, we explore generalizations of the CMN to multipartite systems based on matricizations of the correlation tensor. It is shown that the CMN is able to detect and differentiate classes of multipartite entangled states. We further analyze the correlations within the reduced density matrices and show their significance for entanglement detection. Finally, we employ matricizations of the correlation tensor for introducing a measure of global quantum discord.

Scattering-type scanning near-field optical microscopy is a powerful imaging technique for studying materials beyond the diffraction limit. However, interpreting near-field measurements poses challenges in mapping the response of polaritonic structures to meaningful physical properties. To address this, we propose a theory based on the transfer matrix method to simulate the near-field response of 1D polaritonic structures. Our approach provides a computationally efficient and accurate analytical theory, relating the near-field response to well-defined physical properties. This work enhances the understanding of near-field images and complex polaritonic phenomena. Finally, this scattering theory can extend to other systems like atoms or nanoparticles near a waveguide.

Intracellular monitoring of pH and polarity is crucial for understanding cellular processes and functions. This study employed pH- and polarity-sensitive nanomaterials such as carbon dots (CDs) for the intracellular sensing of pH, polarity, and viscosity using integrated time-resolved fluorescence anisotropy (FA) imaging (TR-FAIM) and fluorescence lifetime (FLT) imaging microscopy (FLIM), thereby enabling comprehensive characterization. The functional groups on the surface of CDs exhibit sensitivity to changes in the microenvironment, leading to variations in fluorescence intensity (FI) and FLT according to pH and polarity. The FLT of CDs in aqueous solution changed gradually from 6.38 ± 0.05 ns to 8.03 ± 0.21 ns within a pH range of 2–8. Interestingly, a complex relationship of FI and FLT was observed during measurements of CDs with decreasing polarity. However, the FA and rotational correlation time (θ) increased from 0.062 ± 0.019 to 0.112 ± 0.023 and from 0.49 ± 0.03 ns to 2.01 ± 0.27 ns, respectively. This increase in FA and θ was attributed to the higher viscosity accompanying the decrease in polarity. Furthermore, CDs were found to bind to three locations in Escherichia coli: the cell wall, inner membrane, and cytoplasm, enabling intracellular characterization using FI and FA decay imaging. FLT provided insights into cytoplasmic pH (7.67 ± 0.48), which agreed with previous works, as well as the decrease in polarity in the cell wall and inner membrane. The CD aggregation was suspected in certain areas based on FA, and the θ provided information on cytoplasmic heterogeneity due to the aggregation and/or interactions with …

Three-dimensional porous nanostructured materials are considered superior materials for energy storage applications due to their high storage capability. A nickel copper-cobalt oxide (NCC) composite with a uniform 3-D porous nanostructure (positive electrode materials) and luffa sponge-derived activated carbon (LPAC) with honeycomb-like structure (negative electrode materials) were synthesized by a simple hydrothermal and chemical method. A sample of the nickel-copper cobalt oxide-5 (NCC-5) nanocomposite reached a high specific capacitance of 1048 F/g at the current density of 0.5 A/g. The NCC-5 nanocomposite sample shows a retention capacity of 93 % after 10,000 charge and discharge cycles with 95 % of Coulombic efficiency (CE). The LPAC illustrates a remarkable specific capacitance of 909 F/g at 1 A/g of current density, compared to the best literature value of 400 F/g. The full-cell NCC-5//LPAC …

Since 2011, 2D transition metal carbides, carbonitrides and nitrides known as MXenes have gained huge attention due to their attractive chemical and electronic properties. The diverse functionalities of MXenes make them a promising candidate for multitude of applications. Recently, doping MXene with metallic and non-metallic elements has emerged as an exciting new approach to endow new properties to this 2D systems, opening a new paradigm of theoretical and experimental studies. In this review, we present a comprehensive overview on the recent progress in this emerging field of doped MXenes. We compare the different doping strategies; techniques used for their characterization and discuss the enhanced properties. The distinct advantages of doping in applications such as electrocatalysis, energy storage, photovoltaics, electronics, photonics, environmental remediation, sensors, and biomedical …

Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl-, and the blockage of active sites by Ca2+/Mg2+ precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na+ exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl- corrosion and Ca2+/Mg2+ precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm−2 and 100 mA cm …

Optical fibers are an excellent sensor platform. However, the detection and analysis of media outside the cladding and coating of standard fibers represent a long-standing challenge: light that is guided in the single optical core mode does not reach these media. Cladding modes help work around this difficulty, as their transverse profiles span the entire cross-section of the fiber cladding and reach its outer boundary. In this tutorial, we introduce and discuss in detail two recent advances in optical fiber sensors that make use of cladding modes. Both concepts share optomechanics as a common underlying theme. First, we describe a spatially continuous distributed analysis using the optical cladding modes of the fiber. Light is coupled to these modes using Brillouin dynamic gratings, which are index perturbations associated with acoustic waves in the core that are stimulated by light. Unlike permanent gratings, which …