BINA

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 …

Nuclear magnetic resonance (NMR) properties of solvated molecules are significantly affected by the solvent. We, therefore, employ a polarization consistent framework that efficiently addresses the solvent polarizing environment effects. Toward this goal a dielectric screened range separated hybrid (SRSH) functional is invoked with a polarizable continuum model (PCM) to properly represent the orbital gap in the condensed phase. We build on the success of range separated hybrid (RSH) functionals to address the erroneous tendency of traditional density functional theory (DFT) to collapse the orbital gap. Recently, the impact of RSH that properly opens up the orbital gap in gas-phase calculations on NMR properties has been assessed. Here, we report the use of SRSH-PCM that produces properly solute orbital gaps in calculating isotropic nuclear magnetic shielding and chemical shift parameters of molecular …

We show that a Bose–Einstein condensate consisting of dark excitons forms in GaAs coupled quantum wells at low temperatures. We find that the condensate extends over hundreds of micrometers, well beyond the optical excitation region, and is limited only by the boundaries of the mesa. We show that the condensate density is determined by spin-flipping collisions among the excitons, which convert dark excitons into bright ones. The suppression of this process at low temperature yields a density buildup, manifested as a temperature-dependent blueshift of the exciton emission line. Measurements under an in-plane magnetic field allow us to preferentially modify the bright exciton density and determine their role in the system dynamics. We find that their interaction with the condensate leads to its depletion. We present a simple rate-equations model, which well reproduces the observed temperature, power, and …

Considering the global spread of bacterial infections, the development of anti-biofilm surfaces with high antimicrobial activities is highly desired. This work unraveled a simple, sonochemical method for coating Cu2O nanoparticles (NPs) on three different flexible substrates: polyester (PE), nylon 2 (N2), and polyethylene (PEL). The introduction of Cu2O NPs on these substrates enhanced their surface hydrophobicity, induced ROS generation, and completely inhibited the growth of sensitive (Escherichia coli and Staphyloccocus aureus) and drug-resistant (MDR E. coli and MRSA) planktonic and biofilm. The experimental results confirmed that Cu2O-PE exhibited complete biofilm mass reduction ability for all four strains, whereas Cu2O-N2 showed more than 99% biomass inhibition against both drug-resistant and sensitive pathogens in 6 h. Moreover, Cu2O-PEL also indicated a 99.95, 97.73, 98.00, and 99.20 …

We show that a Bose–Einstein condensate consisting of dark excitons forms in GaAs coupled quantum wells at low temperatures. We find that the condensate extends over hundreds of micrometers, well beyond the optical excitation region, and is limited only by the boundaries of the mesa. We show that the condensate density is determined by spin-flipping collisions among the excitons, which convert dark excitons into bright ones. The suppression of this process at low temperature yields a density buildup, manifested as a temperature-dependent blueshift of the exciton emission line. Measurements under an in-plane magnetic field allow us to preferentially modify the bright exciton density and determine their role in the system dynamics. We find that their interaction with the condensate leads to its depletion. We present a simple rate-equations model, which well reproduces the observed temperature, power, and …

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.

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 …

Extreme value (EV) statistics of correlated systems are widely investigated in many fields, spanning the spectrum from weather forecasting to earthquake prediction. Does the unavoidable discrete sampling of a continuous correlated stochastic process change its EV distribution? We explore this question for correlated random variables modeled via Langevin dynamics for a particle in a potential field. For potentials growing at infinity faster than linearly and for long measurement times, we find that the EV distribution of the discretely sampled process diverges from that of the full continuous dataset and converges to that of independent and identically distributed random variables drawn from the process’s equilibrium measure. However, for processes with sublinear potentials, the long-time limit is the EV statistics of the continuously sampled data. We treat processes whose equilibrium measures belong to the three EV …

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 …

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 …

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 …

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 …

BackgroundThe main objective is related to the capability of integrating into minimally invasive and ultra-thin disposable micro-endoscopic tool, a modality of realizing high-resolution imaging through scattering medium such as blood while performing medical procedure. In this research we aim for the first time to present a time-multiplexing super-resolving approach exhibiting enhanced focus sensitivity, generated by 3D spatial filtering, for significant contrast increase in images collected through scattering medium.MethodOur innovative method of imaging through scattering media provides imaging of only one specific object plane in scattering medium’s volume while suppressing the noise coming from all other planes. The method should be assisted with axial scanning to perform imaging of the entire 3D object’s volume. In our developed optical system noise suppression is achieved by 3D spatial filtering …

A two-dimensional multimode random laser emitting in the visible frequency range of the optical spectrum is proposed, designed and investigated, in which optical feedback is provided by randomly-distributed air holes embedded in dye-doped polymer film. Dependence of lasing threshold on scatterer density and pump spot size has been investigated. Furthermore, peak of the gain curve shows systematic spectral blue shift with increasing scatterer density, as well as pump spot size. Such a 2D random laser provides with a compact on-chip tunable laser source and a unique platform to explore non-Hermitian photonics in the visible

In recent years, lignin has drawn increasing attention for different applications due to its intrinsic antibacterial and antioxidant properties, coupled with biodegradability and biocompatibility. However, chemical modification or combination with metals is usually required to increase its antimicrobial functionality and produce biobased added-value materials for applications wherein bacterial growth should be avoided, such as biomedical and food industries. In this work, a sonoenzymatic approach for the simultaneous functionalization and nanotransformation of lignin to prepare metal-free antibacterial phenolated lignin nanoparticles (PheLigNPs) is developed. The grafting of tannic acid, a natural phenolic compound, onto lignin was achieved by an environmentally friendly approach using laccase oxidation upon the application of high-intensity ultrasound to rearrange lignin into NPs. PheLigNPs presented higher …

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 …

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.

Neural activity research has recently gained signi cant attention due to its association with sensory information and behavior control. However, current methods of brain activity sensing require expensive equipment and physical contact with the subject.We propose a novel photonic-based method for remote detection of human senses. Physiological processes associated with hemodynamic activity due to activation of the cerebral cortex affected by different senses have been detected by remote monitoring of nano‐vibrations generated due to the transient blood ow to speci c regions of the brain. We have found that combination of defocused, self‐interference random speckle patterns with a spatiotemporal analysis using Deep Neural Network (DNN) allows associating between the activated sense and the seemingly random speckle patterns.

Brillouin optical time domain analysis of coupling to cladding modes of standard, coated fiber is demonstrated. Uncertainty in local changes of effective indices is below 10-6 RIU. Local effect of acetone on coating is identified.

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 need for high power density cathodes for Li‐ion batteries can be fulfilled by application of a high charging voltage above 4.5 V. As lithium cobalt oxide (LCO) remains a dominant commercial cathode material, tremendous efforts are invested to increase its charging potential toward 4.6 V. Yet, the long‐term performance of high voltage LCO cathodes still remains poor. Here, an integrated approach combining the application of an aluminum fluoride coating and the use of electrolyte solutions comprising 1:1:8 mixtures of difluoroethylene:fluoroethylene carbonate:dimethyl carbonate and 1 m LiPF6 is reported. This results in superior behavior of LCO cathodes charged at 4.6 V with high initial capacity of 223 mAh g−1, excellent long‐term performance, and 78% capacity retention after 500 cycles. Impressive stability is also found at 450 °C with an initial capacity of 220 mAh g−1 and around 84% capacity retention …