Anomalously High Dielectric Strength and Capacitive Energy Density of Thin Entangled Glassy Polymer Films.

The influence of high-intensity electric fields on the stability of polymeric materials is a problem of interest in the design of next-generation energy storage and electronic devices, and for understanding the limits of stability of polymer films exposed to large electric fields generally. Here, we show that the dielectric strength of entangled glassy polymer films increases as an inverse power-law of the film thickness for "ultrathin" films below a micron in thickness. The dielectric strength enhancement in these polymer films becomes as large as ≈2 GV/m in films thinner than 100 nm, but in this thickness regime, the increase of the dielectric strength depends strongly on the polymer mass, sample aging time, and the method of film preparation.

Aflatoxin B-induced DNA adduct formation in murine kidney and liver.

Aflatoxicosis is a life-threatening nephrotoxic condition arising from eating foods highly contaminated with aflatoxin-producing molds. Additionally, chronic aflatoxin exposures are linked to enhanced hepatocellular carcinomas. Using recent advances in mass spectrometry for the detection of aflatoxin B (AFB) DNA adducts, we present data which show generation of these adducts in the kidney, albeit at ≈100-fold lower levels than in the liver of the same animal.

Analysis of TEM micrographs with deep learning reveals APOE genotype-specific associations between HDL particle diameter and Alzheimer's dementia.

High-density lipoprotein (HDL) particle diameter distribution is informative in the diagnosis of many conditions, including Alzheimer's disease (AD). However, obtaining an accurate HDL size measurement is challenging. We demonstrated the utility of measuring the diameter of more than 1,800,000 HDL particles with the deep learning model YOLOv7 (you only look once) from micrographs of 183 HDL samples, including patients with dementia or normal cognition (controls).

: active learning in neutron reflectometry for fast data acquisition.

Neutron reflectometry (NR) is a powerful technique for interrogating the structure of thin films at interfaces. Because NR measurements are slow and instrument availability is limited, measurement efficiency is paramount. One approach to improving measurement efficiency is active learning (AL), in which the next measurement configurations are selected on the basis of information gained from the partial data collected so far.

Enhanced Gain Extrapolation Technique: A Third-Order Scattering Approach For High-Accuracy Antenna Gain, Sparse Sampling, At Fresnel Distances.

In this paper we describe an enhanced three-antenna gain extrapolation technique that allows one to determine antenna gain with significantly fewer data points and at closer distances than with the well-established traditional three-antenna gain extrapolation technique that has been in use for over five decades. As opposed to the traditional gain extrapolation technique, where high-order scattering is purposely ignored so as to isolate only the direct antenna-to-antenna coupling, we show that by incorporating third-order scattering the enhanced gain extrapolation technique can be obtained. The theoretical foundation using third-order scattering is developed and experimental results are presented comparing the enhanced technique and traditional technique for two sets of internationally recognized NIST reference standard gain horn antennas at X-band and Ku-band.

Hydride Formation and Decomposition on Cu(111) in HClO.

Cu electrodeposition and the electrocatalysis of hydrogenation reactions thereupon involve significant interactions with adsorbed hydrogen. Electrochemical mass spectrometry (EC-MS) is used to explore the formation and decomposition of surface hydride on Cu(111) in 0.1 mol L HClO.

A mirror-image experiment: Sorting carbon nanotubes by L-DNA.

DNA has found increasing applications in molecular engineering, yet its chiral property has rarely been utilized. Here, we report a mirror-image experiment using naturally occurring D-DNA and its enantiomer L-DNA to sort a chiral mixture of single-wall carbon nanotubes (SWCNTs). We find that parity conservation leads to a robust experimental outcome: changing DNA chirality results in handedness inversion of the purified nanotube.

Hyperspectral analysis to assess gametocytogenesis stage progression in malaria-infected human erythrocytes.

Significance: Developments of anti-gametocyte drugs have been delayed due to insufficient understanding of gametocyte biology. We report a systematic workflow of data processing algorithms to quantify changes in the absorption spectrum and cell morphology of single malaria-infected erythrocytes. These changes may serve as biomarkers instrumental for the future development of antimalarial strategies, especially for anti-gametocyte drug design and testing.

A Method to Evaluate Orientation-Dependent Errors in the Center of Contrast Targets Used with Terrestrial Laser Scanners.

Terrestrial laser scanners (TLS) are portable dimensional measurement instruments used to obtain 3D point clouds of objects in a scene. While TLSs do not require the use of cooperative targets, they are sometimes placed in a scene to fuse or compare data from different instruments or data from the same instrument but from different positions. A contrast target is an example of such a target; it consists of alternating black/white squares that can be printed using a laser printer.

Proximal remote sensing: an essential tool for bridging the gap between high-resolution ecosystem monitoring and global ecology.

A new proliferation of optical instruments that can be attached to towers over or within ecosystems, or 'proximal' remote sensing, enables a comprehensive characterization of terrestrial ecosystem structure, function, and fluxes of energy, water, and carbon. Proximal remote sensing can bridge the gap between individual plants, site-level eddy-covariance fluxes, and airborne and spaceborne remote sensing by providing continuous data at a high-spatiotemporal resolution. Here, we review recent advances in proximal remote sensing for improving our mechanistic understanding of plant and ecosystem processes, model development, and validation of current and upcoming satellite missions.

Well-Characterized Polyethyleneimine-/Carboxylated-Polyethylene-Glycol-Functionalized Gold Nanoparticles as Prospective Nanoscale Control Materials for In Vitro Cell Viability Assays: Particle Characterization and Toxicity Tests in Eight Mammalian Cell Lines.

The safety screening of manufactured nanomaterials (MNMs) is essential for their adoption by consumers and the marketplace. Lately, animal-based testing has been replaced by mechanistically informative in vitro assays due to the requirements of regulatory agencies. Cell viability assays are widely employed for manufactured nanomaterial hazard screening as a first-tier approach.

ETSpy: A HyperSpy extension package for electron tomography data processing and reconstruction.

Electron tomography is a powerful tool for the three-dimensional characterization of materials at the nano- and atomic-scales. A typical workflow for tomography involves several pre-processing steps that may include spatial binning, image registration, and tilt-axis alignment depending upon the nature of the acquired data. Here we describe the capabilities of a new, open-source software package named ETSpy that builds upon the widely used HyperSpy package.

Platinum hydride formation during cathodic corrosion in aqueous solutions.

Cathodic corrosion is an electrochemical phenomenon that etches metals at moderately negative potentials. Although cathodic corrosion probably occurs by forming a metal-containing anion, such intermediate species have not yet been observed. Here, aiming to resolve this long-standing debate, our work provides such evidence through X-ray absorption spectroscopy.

Neuromorphic computing at scale.

Neuromorphic computing is a brain-inspired approach to hardware and algorithm design that efficiently realizes artificial neural networks. Neuromorphic designers apply the principles of biointelligence discovered by neuroscientists to design efficient computational systems, often for applications with size, weight and power constraints. With this research field at a critical juncture, it is crucial to chart the course for the development of future large-scale neuromorphic systems.

Microplastic characterization and transport mode -A flow-integrated approach to sampling urban waterways.

Concentrations of microplastics are both temporally and spatially variable in streamflow. Yet, an overwhelming number of published field studies do not target a range of flow conditions and fail to adequately capture particle transport within the full flow field. Since microplastic flux models rely on the representativeness of available data, current predictions of riverine exports contain substantial error.

Collective motion and its connection to the energy landscape in 2D soft crystals.

We examine the collective motion in computational models of a two-dimensional dusty plasma crystal and a charged colloidal suspension as they approach their respective melting transitions. To unambiguously identify rearrangement events in the crystal, we map the trajectory of configurations from an equilibrium molecular dynamics simulation to the corresponding sequence of configurations of local potential energy minima ("inherent structures"). This inherent structure (IS) trajectory eliminates the ambiguity that arises from localized vibrational motion.

Measuring the size of oil droplets in a flow cytometer using Mie resonances: A possible size calibration ladder for 0.5-6 μm.

An emulsion of silicone oil droplets in aqueous buffer produces a distinctive series of peaks or resonances in the side scatter histogram in a flow cytometer. As many as 12 peaks are observed in the violet-side scatter channel at 405 nm, with half that number observed in the blue side scatter channel at 488 nm. Using the index of refraction of the oil and buffer, the wavelength of light, and the collection angle and gain of the instrument, we assign the peaks to specific diameters at which Mie resonances occur.

Glucocorticoids Alter Bone Microvascular Barrier via MAPK/Connexin43 Mechanisms.

Glucocorticoids (GCs) are standard-of-care treatments for inflammatory and immune disorders, and their long-term use increases the risk of osteoporosis. Although GCs decrease bone functionality, their role in bone microvasculature is incompletely understood. Herein, the study investigates the mechanisms of bone microvascular barrier function via osteoblast-endothelial interactions in response to GCs.

Bose-Einstein Condensation of Polaritons at Room Temperature in a GaAs/AlGaAs Structure.

We report the canonical properties of the Bose-Einstein condensation of polaritons in the weak coupling regime, seen previously in many low-temperature experiments, at room temperature in a GaAs/AlGaAs structure. These effects include a nonlinear energy shift of the polaritons, showing that they are not noninteracting photons, and dramatic line narrowing due to coherence, giving coherent emission with a spectral width of 0.24 meV at room temperature with no external stabilization.

Production, Isolation, and Characterization of Stable Isotope-Labeled Standards for Mass Spectrometric Measurements of Oxidatively-Damaged Nucleosides in RNA.

RNA undergoes oxidatively induced damage in living organisms analogous to DNA. RNA is even more vulnerable to damage than DNA due to its greater abundance, single-strandedness, lack of repair and chromatin proteins shield, and instability, among other effects. RNA damage can adversely affect gene expression, leading to protein synthesis alterations, cell death, and other detrimental biological consequences.

Analytical Quality Evaluation of the Tox21 Compound Library.

The analytical quality of compounds subjected to high-throughput screening (HTS) impacts accurate interpretation of assay results, with poor quality samples potentially leading to false negatives or positives. The Tox21 "10K" library consists of over 8900 unique compounds, spanning a diverse landscape of environmental and pharmaceutical chemicals, posing opportunities and challenges for analytical quality control (QC) determinations. Tox21 sample plates stored in DMSO at ambient conditions for 0 (T0) and/or 4 months (T4), totaling more than 13K unique sample identifiers (Tox21 IDs), were subjected to various analyses, including liquid and gas chromatography mass spectrometry (LC-MS, GC-MS) and nuclear magnetic resonance (NMR).

Determining the Rates of α-Tocopherol Movement in DPPC Vesicles Using Small Angle Neutron Scattering.

α-Tocopherol (αtoc, vitamin E) is an essential nutrient sufficiently acquired through a balanced diet. This fat-soluble vitamin is most known for its antioxidative properties, however, its fundamental mechanism of action in cellular membranes remains unknown. To this end, we use time-resolved small angle neutron scattering (TR-SANS) and a contrast matching scheme to determine intervesicular exchange (k) and intrabilayer flip-flop (k) rates of αtoc in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles.

Robust discrimination between closely related species of salmon based on DNA fragments.

Closely related species of Salmonidae, including Pacific and Atlantic salmon, can be distinguished from one another based on nucleotide sequences from the cytochrome c oxidase sub-unit 1 mitochondrial gene (COI), using ensembles of fragments aligned to genetic barcodes that serve as digital proxies for the relevant species. This is accomplished by exploiting both the nucleotide sequences and their quality scores recorded in a FASTQ file obtained via Next Generation (NextGen) Sequencing of mitochondrial DNA extracted from Coho salmon caught with hook and line in the Gulf of Alaska. The alignment is done using MUSCLE (Muscle 5.

Wavemeter calibration by frequency comb.

Upgrades to the vacuum wavelength calibration service at the National Institute of Standards and Technology are reported. The instrumentation centerpiece is an optical frequency comb stabilized to a GPS-disciplined oscillator, thereby providing direct traceability to the SI second. Historically, the service has covered lasers at the popular interferometry wavelengths red and green.