BINA

Here, three types of surface coatings based on adsorption of organic aromatic acids or their Li salts are applied as functional coating substrates to engineer the surface properties of high voltage LiNi0.5Mn1.5O4 (LNMO) spinel cathodes. The materials used as coating include 1,3,5‐benzene‐tricarboxylic acid (trimesic acid [TMA]), its Li‐salt, and 1,4‐benzene‐dicarboxylic acid (terephthalic acid). The surface coating involves simple ethanol liquid‐phase mixing and low‐temperature heat treatment under nitrogen flow. In typical comparative studies, TMA‐coated (3–5%) LNMO cathodes deliver >90% capacity retention after 400 cycles with significantly improved rate performance in Li‐coin cells at 30 °C compared to uncoated material with capacity retention of ≈40%. The cathode coating also prevents the rapid drop in the electrochemical activity of high voltage Li cells at 55 °C. Studies of high voltage full cells …

Anionic redox provides an effective way to overcome the capacity bottleneck of sodium‐ion batteries. A dominant role is played by the arrangement of alkali A and transition metal M in the NaxAyM1‐yO2 superstructure. Here, in situ X‐ray diffraction and ex situ 7Li nuclear magnetic resonance of P2 type Na0.6Li0.2Mn0.8O2 with ribbon‐ordered superstructure illustrate structural changes and explain the evolution of the electrochemical behavior of electrodes comprising this active mass, during cycling. Upon substitution of a small amount of manganese by iron, Na0.67Li0.2Mn0.73Fe0.07O2 is formed with a honeycomb‐ordered superstructure. Experimental characterizations and theoretical calculations elucidate the effect of iron on oxygen redox activity. The iron‐doped material considerably outperforms the undoped Na0.6Li0.2Mn0.8O2 as a cathode material for rechargeable Na‐ion batteries. This research reveals …

Background: Glioblastoma is the most lethal primary brain malignancy in adults. Standard of care treatment, consisting of temozolomide (TMZ) and adjuvant radiotherapy (RT), mostly does not prevent local recurrence. The inability of drugs to enter the brain, in particular antibody-based drugs and radiosensitizers, is a crucial limitation to effective glioblastoma therapy. Methods: Here, we developed a combined strategy using radiosensitizer gold nanoparticles coated with insulin to cross the blood–brain barrier and shuttle tumor-targeting antibodies (cetuximab) into the brain. Results: Following intravenous injection to an orthotopic glioblastoma mouse model, the nanoparticles specifically accumulated within the tumor. Combining targeted nanoparticle injection with TMZ and RT standard of care significantly inhibited tumor growth and extended survival, as compared to standard of care alone. Histological analysis of tumors showed that the combined treatment eradicated tumor cells, and decreased tumor vascularization, proliferation, and repair. Conclusions: Our findings demonstrate radiosensitizer nanoparticles that effectively deliver antibodies into the brain, target the tumor, and effectively improve standard of care treatment outcome in glioblastoma.

Exponential, and not Gaussian, decay of probability density functions was studied by Laplace in the context of his analysis of errors. Such Laplace propagators for the diffusive motion of single particles in disordered media were recently observed in numerous experimental systems. What will happen to this universality when an external driving force is applied? Using the ubiquitous continuous time random walk with bias, and the Crooks relation in conjunction with large deviations theory, we derive two properties of the positional probability density function that hold for a wide spectrum of random walk models: (I) Universal asymmetric exponential decay of for large , and (II) Existence of a time transformation that for large allows to express in terms of the propagator of the unbiased process (measured at a shorter time). These findings allow us to establish how the symmetric exponential-like tails, measured in many unbiased processes, will transform into asymmetric Laplace tails when an external force is applied.

In the last 20 years, the use of electron paramagnetic resonance (EPR) has made a pronounced and lasting impact in the field of structural biology. The advantage of EPR spectroscopy over other structural techniques is its ability to target even minor conformational changes in any biomolecule or macromolecular complex, independent of its size or complexity, or whether it is in solution or in the cell during a biological or chemical reaction. Here, we focus on the use of EPR spectroscopy to study transmembrane transport and transcription mechanisms. We discuss experimental and analytical concerns when referring to studies of two biological reaction mechanisms, namely, transfer of copper ions by the human copper transporter hCtr1 and the mechanism of action of the Escherichia coli copper-dependent transcription factor CueR. Last, we elaborate on future avenues in the field of EPR structural biology.

We explore the extreme value (EV) statistics of correlated random variables modeled via Langevin equations. Starting with an Ornstein-Uhlenbeck process, we find that when the trajectory is sampled discretely, long measurement times make the EV distribution converge to that originating from independent and identically distributed variables drawn from the process' equilibrium measure. A transition occurs when the sampling interval vanishes, for which case the EV statistics corresponds to that of the continuous process. We expand these findings to general potential fields, revealing that processes with a force that diminishes for large distances exhibit an opposite trend. Hence, we unveil a second transition, this time with respect to the potential's behavior at large displacements.

Two-photon interactions of entangled-photon pairs with metallic nanoparticles (NPs) can be enhanced by localized surface-plasmon resonance. Recently, we have described how the properties of this quantum light-matter interaction can be deduced from classical second-harmonic generation measurements performed using a reference-free hyper-Rayleigh scattering method. Herein, we report the results of such classical-light characterization measurements. We obtain a large hyperpolarizability for the NPs, present the dependence of the hyperpolarizability on the NPs' spectral features, and show a dipolar emission pattern for the second-harmonic signal. Our results can be used to optimize entangled-photon pair interactions with metallic NPs to enable first ever detection of this process. Moreover, these results suggest that NPs may be used as source for ultra-broadband entangled-photon pairs through nonphase …

Pt-based nanoparticles (NPs) are used as electrocatalysts for the oxygen reduction reaction (ORR) that occurs at the cathode of a proton exchange membrane fuel cell, because of their high efficiency. Among these NPs, PtCu electrocatalysts are an important subclass, in which composition, morphology, size, crystal structure, and atomic distribution are tuned to optimize the performance and durability of the catalyst. Most of the efforts so far in the field have been dedicated toward increasing the catalytic activity and stability of these NPs, while reducing the amount of precious material. In this paper, we present a solvothermal method used for the synthesis of carbon-supported octahedral PtCu NPs that show high efficiency toward the ORR. In particular, a specific activity of 1.02 mA cm–2 was achieved after 10,000 cycles (accelerated degradation test) in which 84% of the electrochemical surface area was maintained …

Two-photon interactions of entangled-photon pairs with metallic nanoparticles (NPs) can be enhanced by localized surface-plasmon resonance. Recently, we have described how the properties of this quantum light-matter interaction can be deduced from classical second-harmonic generation measurements performed using a reference-free hyper-Rayleigh scattering method. Herein, we report the results of such classical-light characterization measurements. We obtain a large hyperpolarizability for the NPs, present the dependence of the hyperpolarizability on the NPs' spectral features, and show a dipolar emission pattern for the second-harmonic signal. Our results can be used to optimize entangled-photon pair interactions with metallic NPs to enable first ever detection of this process. Moreover, these results suggest that NPs may be used as source for ultra-broadband entangled-photon pairs through nonphase …

The important phenomenon of electrical double layer (EDL) is often described by mathematical relations between surface charges, variation of electrostatic potentials with distance and distribution of ions across the interface between charged surfaces (or particles) and electrolyte solutions. A major advance was made in the last decade in understanding complex EDL relationships with an emphasis on nano-porous carbonaceous materials. These understandings were usually exploited for the interpretation of electro-sorption phenomena connected to capacitive deionization (CDI) processes. The aim of this short paper is to demonstrate, based on previous studies, how models of EDL in nano-porous carbons can be the basis for modification of carbonaceous materials for other applications, like sensors and energy extraction from salinity gradients.

Genetically engineered T cells are a powerful new modality for cancer immunotherapy. However, their clinical application for solid tumors is challenging, and crucial knowledge on cell functionality in vivo is lacking. Here, we fabricated a nanoprobe composed of dendrimers incorporating a calcium sensor and gold nanoparticles, for dual-modal monitoring of engineered T cells within a solid tumor. T cells engineered to express a melanoma-specific T-cell receptor and loaded with the nanoprobe were longitudinally monitored within melanoma xenografts in mice. Fluorescent imaging of the nanoprobe's calcium sensor revealed increased intra-tumoral activation of the T cells over time, up to 24 h. Computed tomography imaging of the nanoprobe's gold nanoparticles revealed the cells' intra-tumoral distribution pattern. Quantitative analysis revealed the intra-tumoral T cell quantities. Thus, this nanoprobe reveals intra …

Ni-rich LiNi1–x–yCoxMnyO2 (1 – x – y > 0.5) (NCMs) cathode materials have shown great promise in energy-intensive applications, such as electric vehicles. However, as many layered cathodes do, they suffer from structural and electrochemical degradation during cycling. In this study, we show that Nd- and Y-doped materials, Li(Ni0.85Co0.1Mn0.05)0.995Nd0.005O2 and Li(Ni0.85Co0.1Mn0.05)0.995Y0.005O2, have significantly better structural, electrochemical, and thermal properties compared to the reference LiNi0.85Co0.1Mn0.05O2 (NCM85) due to enhanced structural stability. The doped electrodes were found to have significantly higher specific discharge capacities, better capacity retention, and lower voltage hysteresis compared to the reference (undoped) electrodes. SEM images of the focused-ion beam (FIB) cut of the particles of the doped material showed that they have less cracks when compared …

Various conditions cause dispersions of particulate matter to circulate inside the anterior chamber of a human eye. These dispersed particles might reduce visual acuity or promote elevation of intraocular pressure (IOP), causing secondary complications such as particle related glaucoma, which is a major cause of blindness. Medical and surgical treatment options are available to manage these complications, yet preventive measures are not currently available. Conceptually, manipulating these dispersed particles in a way that reduces their negative impact could prevent these complications. However, as the eye is a closed system, manipulating dispersed particles in it is challenging. Standing acoustic waves have been previously shown to be a versatile tool for manipulation of bioparticles from nano-sized extracellular vesicles up to millimeter-sized organisms. Here we introduce for the first time a novel method utilizing standing acoustic waves to noninvasively manipulate intraocular particles inside the anterior chamber. Using a cylindrical acoustic resonator, we show ex vivo manipulation of pigmentary particles inside porcine eyes. We study the effect of wave intensity over time and rule out temperature changes that could damage tissues. Optical coherence tomography and histologic evaluations show no signs of damage or any other side effect that could be attributed to acoustic manipulation. Finally, we lay out a clear pathway to how this technique can be used as a non-invasive tool for preventing secondary glaucoma. This concept has the potential to control and arrange intraocular particles in specific locations without causing any damage to …

In nanophotonics, small mode volumes, high-quality factor (Q) 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 (TI) are a class of insulating materials that host topologically protected surface states, some of which exhibit extraordinary high permittivity values. Here, we study the optical properties of TI bismuth telluride (Bi2Te3) single crystals. We find 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, we demonstrate that Bi2Te3 metasurfaces are capable of squeezing light in deep subwavelength structures, with the fundamental magnetic dipole (MD) resonance confined in unit cell size smaller than {\lambda}/10. We further show that dense ultrathin metasurface arrays can simultaneously provide large magnetic and electric field enhancements arising from the surface metallic states and the high index of the bulk. These findings demonstrate the potential of chalcogenide TI materials as a platform leveraging the unique combination of ultra-high-index dielectric response with surface metallic states for metamaterial design and nanophotonic applications in sensing, non-linear generation, and quantum information.

We investigate a tight binding quantum walk on a graph. Repeated stroboscopic measurements of the position of the particle yield a measured "trajectory", and a combination of classical and quantum mechanical properties for the walk are observed. We explore the effects of the measurements on the spreading of the packet on a one dimensional line, showing that except for the Zeno limit, the system converges to Gaussian statistics similarly to a classical random walk. A large deviation analysis and an Edgeworth expansion yield quantum corrections to this normal behavior. We then explore the first passage time to a target state using a generating function method, yielding properties like the quantization of the mean first return time. In particular, we study the effects of certain sampling rates which cause remarkable change in the behavior in the system, like divergence of the mean detection time in finite systems and a decomposition of the phase space into mutually exclusive regions, an effect that mimics ergodicity breaking, whose origin here is the destructive interference in quantum mechanics. For a quantum walk on a line we show that in our system the first detection probability decays classically like , this is dramatically different compared to local measurements which yield a decay rate of , indicating that the exponents of the first passage time depends on the type of measurements used.

Transport in disordered media, such as those involving charge carriers in amorphous semiconductors, or contaminants in hydrogeological systems, are often described by time scale-free processes. We study the statistical properties of the first passage time of biased processes in different models, and employ the big jump principle that shows the dominance of the maximum trapping time on the first passage time. Inspired by the restart paradigm, we demonstrate that the removal of this maximum significantly expedites transport. As the disorder increases, the system enters a phase where the removal shows a dramatic effect. Our results show how we may speed up transport in strongly disordered systems exploiting scale invariance.

Ultra-thin, transparent films are being used as protective layers on semiconductors, solar cells, as well as for nano-composite materials and optical coatings. Nano-sensors, photonic devices and calibration tools for axial super-resolution microscopies, all rely on the controlled fabrication and analysis of ultra-thin layers. Here, we describe a simple, non-invasive, optical technique for simultaneously characterizing the refractive index, thickness, and homogeneity of nanometric transparent films. In our case, these layers are made of the biomimetic polymer, My-133-MC, having a refractive index of 1.33, so as to approach the cytosol for biological applications. Our technique is based on the detection in the far field and the analysis of supercritical angle fluorescence (SAF), i.e., near-field emission from molecular dipoles located very close to the dielectric interface. SAF emanates from a 5-nm J-aggregate emitter layer deposited on and in contact with the inspected polymer film. Our results compare favorably to that obtained through a combination of atomic force and electron microscopy, surface-plasmon resonance spectroscopy and ellipsometry. We illustrate the value of the approach in two applications, (i), the measurement of axial fluorophore distance in a total internal reflection fluorescence geometry; and, (ii), axial super-resolution imaging of organelle dynamics in a living biological sample, cortical astrocytes, an important type of brain cell. In the later case, our approach removes uncertainties in the interpretation of the nanometric axial dynamics of fluorescently labeled vesicles. Our technique is cheap, versatile and it has obvious applications in …

Single Nucleotide Polymorphism markers (SNPs) have great potential to identify individuals, family relations, biogeographical ancestry, and phenotypic traits. In many forensic situations DNA mixtures of a victim and an unknown suspect exist. Extracting from such samples the suspect's SNP profile can be used to assist investigation and gather intelligence. Computational tools to determine inclusion/exclusion of a known individual from a mixture exist, but no algorithm to extract an unknown SNP profile without a list of suspects is available. We present here AH-HA, a novel computational approach for extracting an unknown SNP profile from a whole genome sequencing (WGS) of a two person mixture. It utilizes techniques similar to the ones used in haplotype phasing. It constructs the inferred genotype as an imperfect mosaic of haplotypes from a reference panel of the target population. It is shown to outperform more simplistic approaches, maintaining high performance through a wide range of sequencing depths (500x-5x). AH-HA can be applied in cases of victim-suspect mixtures and improve the capabilities of the investigating forces. This approach can be extended to more complex mixtures, with more donors and less prior information, further motivating the development of SNP based forensics technologies.

Carbon-based nanoparticles (NPs) are widely used in nanotechnology. Among them, nanodiamonds (NDs) are suitable for biotechnology and are especially interesting for skin delivery and topical treatments. However, noninvasive detection of NDs within the different skin layers or analyzing their penetration ability is complicated due to the turbid nature of the tissue. The iterative multiplane optical properties extraction (IMOPE) technique detects differences in the optical properties of the measured item by a phase-image analysis method. The phase image is reconstructed by the multiplane Gerchberg–Saxton algorithm. This technique, traditionally, detects differences in the reduced scattering coefficients. Here, however, due to the actual size of the NDs, the IMOPE technique’s detection relies on absorption analysis rather than relying on scattering events. In this paper, we use the IMOPE technique to detect the …

Surfaces of classical spherical liquid droplets are isotropic, promoting the random distribution of surface-adsorbed molecules. Here we demonstrate a counterintuitive temperature-controlled self-assembly of well-defined and highly ordered patterns of surface-adsorbed fluorescent molecules on the surfaces of water-suspended spherical oil droplets. These patterns are induced by precisely self-positioned, topology-dictated structural defects in a crystalline monolayer covering these droplets’ surfaces over a wide temperature range. We elucidate the pattern formation mechanism, visualize the defects’ positions and map the stress fields within the surface crystal. The observed phenomena provide insights into the interfacial freezing effect on curved surfaces, enable precise positioning of functional ligands on droplets for their self-assembly into higher-hierarchy structures– and may also play an important role in vital …

Surfaces of classical spherical liquid droplets are isotropic, promoting the random distribution of surface-adsorbed molecules. Here we demonstrate a counterintuitive temperature-controlled self-assembly of well-defined and highly ordered patterns of surface-adsorbed fluorescent molecules on the surfaces of water-suspended spherical oil droplets. These patterns are induced by precisely self-positioned, topology-dictated structural defects in a crystalline monolayer covering these droplets’ surfaces over a wide temperature range. We elucidate the pattern formation mechanism, visualize the defects’ positions and map the stress fields within the surface crystal. The observed phenomena provide insights into the interfacial freezing effect on curved surfaces, enable precise positioning of functional ligands on droplets for their self-assembly into higher-hierarchy structures– and may also play an important role in vital …