11,208 results match your criteria: "‡National Institute of Standards and Technology[Affiliation]"

Microplastic pollution is an emerging stressor of concern to coral reef ecosystems, which are already threatened by additional global and local level anthropogenic stressors. The effects of ingesting microplastics alone on corals have been well studied, but the effects of the chemical composition of these particles have been understudied. Many microplastic-associated chemicals are endocrine disrupters potentially posing a threat to organismal reproduction.

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Presenting quantitative data using non-standardized color maps potentially results in unrecognized misinterpretation of data. Clinically meaningful color maps should intuitively and inclusively represent data without misleading interpretation. Uniformity of the color gradient for color maps is critically important.

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A localized Zeeman field, intensified at heterostructure interfaces, could play a crucial role in a broad area including spintronics and unconventional superconductors. Conventionally, the generation of a local Zeeman field is achieved through magnetic exchange coupling with a magnetic material. However, magnetic elements often introduce defects, which could weaken or destroy superconductivity.

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Theories of small systems play an important role in the fundamental understanding of finite size effects in statistical mechanics, as well as the validation of molecular simulation results as no computer can simulate fluids in the thermodynamic limit. Previously, a shell particle was included in the isothermal-isobaric ensemble in order to resolve an ambiguity in the resulting partition function. The shell particle removed either redundant volume states or redundant translational degrees of freedom of the system and yielded quantitative differences from traditional simulations in this ensemble.

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Optical parametric oscillation (OPO) in Kerr microresonators can efficiently transfer near-infrared laser light into the visible spectrum. To date, however, chromatic dispersion has mostly limited output wavelengths to >560 nm, and robust access to the whole green light spectrum has not been demonstrated. In fact, wavelengths between 532 nm and 633 nm, commonly referred to as the "green gap", are especially challenging to produce with conventional laser gain.

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Membraneless coacervate microdroplets have long been proposed as model protocells as they can grow, divide, and concentrate RNA by natural partitioning. However, the rapid exchange of RNA between these compartments, along with their rapid fusion, both within minutes, means that individual droplets would be unable to maintain their separate genetic identities. Hence, Darwinian evolution would not be possible, and the population would be vulnerable to collapse due to the rapid spread of parasitic RNAs.

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The solution viscosity and protein-protein interactions (PPIs) as a function of temperature (4-40 °C) were measured at a series of protein concentrations for a monoclonal antibody (mAb) with different formulation conditions, which include NaCl and sucrose. The flow activation energy () was extracted from the temperature dependence of solution viscosity using the Arrhenius equation. PPIs were quantified via the protein diffusion interaction parameter () measured by dynamic light scattering, together with the osmotic second virial coefficient and the structure factor obtained through small-angle X-ray scattering.

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We demonstrate subrecoil Sisyphus cooling using the long-lived ^{3}P_{0} clock state in alkaline-earth-like ytterbium. A 1388-nm optical standing wave nearly resonant with the ^{3}P_{0}→^{3}D_{1} transition creates a spatially periodic light shift of the ^{3}P_{0} clock state. Following excitation on the ultranarrow clock transition, we observe Sisyphus cooling in this potential, as the light shift is correlated with excitation to ^{3}D_{1} and subsequent spontaneous decay to the ^{1}S_{0} ground state.

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The protein dynamical transition at ~200 K, where the biomolecule transforms from a harmonic, non-functional form to an anharmonic, functional state, has been thought to be slaved to the thermal activation of dynamics in its surface hydration water. Here, by selectively probing the dynamics of protein and hydration water using elastic neutron scattering and isotopic labeling, we found that the onset of anharmonicity in the two components around 200 K is decoupled. The one in protein is an intrinsic transition, whose characteristic temperature is independent of the instrumental resolution time, but varies with the biomolecular structure and the amount of hydration, while the one of water is merely a resolution effect.

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Construction of Highly Porous and Robust Hydrogen-Bonded Organic Framework for High-Capacity Clean Energy Gas Storage.

Angew Chem Int Ed Engl

December 2024

State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.

Development of highly porous and robust hydrogen-bonded organic frameworks (HOFs) for high-pressure methane and hydrogen storage remains a grand challenge due to the fragile nature of hydrogen bonds. Herein, we report a strategy of constructing the double-walled framework to target highly porous and robust HOF (ZJU-HOF-5a) for extraordinary CH and H storage. ZJU-HOF-5a features a minimized twofold interpenetration with double-walled structure, in which multiple supramolecular interactions are existed between the interpenetrated walls.

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Biocompatibility testing using in vivo tests is often one of the final evaluations of new dental materials. To reduce the likelihood of failure at this late stage, predictive biocompatibility testing using in vitro methods is needed. In this study, we describe a sensitivity analysis of an oral irritation test by evalu­ating changes in the viability, using the MTT assay, of 3-D models with EpiOral constructs as a case study.

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Simulating the dielectric spectra of solvents requires the nuanced definition of inter- and intra-molecular forces. Non-polarizable force fields, while thoroughly benchmarked for dielectric applications, do not capture all the spectral features of solvents, such as water. Conversely, polarizable force fields have been largely untested in the context of dielectric spectroscopy but include charge and dipole fluctuations that contribute to intermolecular interactions.

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This work presents a detailed determination of site-specific N-glycan distributions of the recombinant influenza glycoproteins hemagglutinin (HA) and neuraminidase. Variation in glycosylation among recombinant glycoproteins is not predictable and can depend on details of the biomanufacturing process as well as details of protein structure. In this study, recombinant influenza proteins were analyzed from eight strains of four different suppliers.

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The Block Copolymer Phase Behavior Database.

J Chem Inf Model

August 2024

Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.

The Block Copolymer Database (BCDB) is a platform that allows users to search, submit, visualize, benchmark, and download experimental phase measurements and their associated characterization information for di- and multiblock copolymers. To the best of our knowledge, there is no widely accepted data model for publishing experimental and simulation data on block copolymer self-assembly. This proposed data schema with traceable information can accommodate any number of blocks and at the time of publication contains over 5400 block copolymer total melt phase measurements mined from the literature and manually curated and simulation data points of the phase diagram generated from self-consistent field theory that can rapidly be augmented.

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We present 3D fully kinetic shearing-box simulations of pair-plasma magnetorotational turbulence with unprecedented macro-to-microscopic scale separation. While retrieving the expected fluid behavior of the plasma at large scales, we observe a steepening of turbulent spectra at kinetic scales and substantial angular-momentum transport linked with kinetic processes. For the first time, we provide a definitive demonstration of nonthermal particle acceleration in kinetic magnetorotational turbulence agnostically of shearing-box initial conditions by means of a novel strategy exploiting synchrotron cooling.

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The Open Databases Integration for Materials Design (OPTIMADE) application programming interface (API) empowers users with holistic access to a growing federation of databases, enhancing the accessibility and discoverability of materials and chemical data. Since the first release of the OPTIMADE specification (v1.0), the API has undergone significant development, leading to the v1.

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Liquid porosimetry experiments reveal a peculiar trend of the intrusion pressure of water in hydrophobic Cu(3,3',5,5'-tetraethyl-4,4'-bipyrazolate) MOF. At lower temperature (T) range, the intrusion pressure (P) increases with T. For higher T values, P first reaches a maximum and then decreases.

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Optimizing Wastewater Surveillance: The Necessity of Standardized Reporting and Proficiency for Public Health.

Am J Public Health

September 2024

Ishi Keenum is with the Civil, Environmental, and Geospatial Department, Michigan Technological University, Houghton. Nancy J. Lin and Alshae' Logan-Jackson are with the Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD. Adam J. Gushgari is with Eurofins Pandemic Prevention Services, Sacramento, CA. Nishita D'Souza is with Department of Fisheries and Wildlife, Michigan State University, East Lansing. Joshua A. Steele is with the Department of Microbiology, Southern California Coastal Water Research Project, Costa Mesa, CA. Devrim Kaya is with the School of Public Health, San Diego State University, CA. Lydia R. Gushgari is with SPOC Proteomics, Inc., Scottsdale, AZ.

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Analysis types and quantification methods applied in UHPLC-MS metabolomics research: a tutorial.

Metabolomics

August 2024

Department of Biochemistry, Cell and Systems Biology, Centre for Metabolomics Research, Institute of Systems, Molecular, and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.

Article Synopsis
  • Different analytical methods in metabolomics and lipidomics include untargeted, targeted, and semi-targeted approaches, with Ultra High Performance Liquid Chromatography-Mass Spectrometry being a key tool due to its efficiency in detecting metabolites.
  • The review aims to clarify the differences among these methods in terms of determining metabolite quantities and to discuss their respective advantages and limitations related to accuracy and precision.
  • The choice of method is influenced by factors such as prior knowledge of metabolites, the need for peak responses or absolute concentrations, and the desired number of metabolites to analyze, with each method providing different reporting capabilities.
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DNA-based Points Accumulation for Imaging in Nanoscale Topography (DNA-PAINT) is an effective super resolution microscopy technique, and its optimization is key to improve nanoscale detection. The state-of-the-art improvements that are at the base of this optimization have been first routinely validated on DNA nanostructure devices before being tested on biological samples. This allows researchers to finely tune DNA-PAINT imaging features in a more controllable environment.

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The design and implementation of dopant-based silicon nanoscale devices rely heavily on knowing precisely the locations of phosphorous dopants in their host crystal. One potential solution combines scanning tunneling microscopy (STM) imaging with atomistic tight-binding simulations to reverse-engineer dopant coordinates. This work shows that such an approach may not be straightforwardly extended to double-dopant systems.

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Thermal desorption (TD) of wipe-based samples was coupled with an in-line dielectric barrier discharge ionization (DBDI) source and rugged compact time-of-flight mass spectrometer (MS) for the detection of explosives, propellants, and postblast debris. The chromatography-free TD-DBDI-MS platform enabled rapid and sensitive detection of organic nitramine, nitrate ester, and nitroaromatic explosives as well as black powder and black powder substitute propellants. Parametric investigations characterized the response to TD temperature and optimized DBDI voltage, aerodynamically assisted entrainment, and fragmentation through in-source collision induced dissociation (isCID).

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Excess "micromotion" of trapped ions due to the residual radio-frequency (rf) trapping field at their location is often undesirable and is usually carefully minimized. Here, we induce precise amounts of excess micromotion on individual ions by adjusting the local static electric field they experience. Micromotion modulates the coupling of an ion to laser fields, ideally tuning it from its maximum value to zero as the ion is moved away from the trap's rf null.

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Porous solids can accommodate and release molecular hydrogen readily, making them attractive for minimizing the energy requirements for hydrogen storage relative to physical storage systems. However, H adsorption enthalpies in such materials are generally weak (-3 to -7 kJ/mol), lowering capacities at ambient temperature. Metal-organic frameworks with well-defined structures and synthetic modularity could allow for tuning adsorbent-H interactions for ambient-temperature storage.

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