We observe the capture and field ionization of individual atoms near the side wall of a single suspended nanotube. Extremely large cross sections for ionization from an atomic beam are observed at modest voltages due to the nanotube's small radius and extended length. The effects of the field strength on both the atomic capture and the ionization process are clearly distinguished in the data, as are prompt and delayed ionizations related to the locations at which they occur. Efficient and sensitive neutral atom detectors can be based on the nanotube capture and wall ionization processes.
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http://dx.doi.org/10.1103/PhysRevLett.104.133002 | DOI Listing |
Sci Rep
January 2025
Astronomical Observatory, Jagiellonian University, Orla 171, Krakow, 30-244, Poland.
The single crystals of lead-free NaBiTiO were grown using the Czochralski method. The energy gaps determined from X-ray photoelectron spectroscopy (XPS) and optical measurements were approximately 2.92 eV.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
There has been a significant recent surge in the number of studies interrogating chiral molecules in the gas phase using photoelectron circular dichroism (PECD) and related techniques. These investigations have revealed new fundamental insights into the structure and dynamics of chiral species and, furthermore, have the potential to revolutionize the field of chiral analysis for more practical and industrial applications. As it has been just over 20 years since the first PECD imaging experiments were demonstrated - and 10 years since the last dedicated general perspective article on the topic - a new overview now seems extremely timely.
View Article and Find Full Text PDFAnalyst
January 2025
Institutes of Biomedical Sciences & Shanghai Stomatological Hospital, Department of Chemistry, Fudan University, Shanghai 200433, China.
Reducing the time required for the detection of bacteria in blood samples is a critical area of investigation in the field of clinical diagnosis. Positive blood culture samples often require a plate culture stage due to the interference of blood cells and proteins, which can result in significant delays before the isolation of single colonies suitable for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. In this study, we developed a non-specific enrichment strategy based on SiO-encapsulated FeO nanoparticles combined with MALDI-TOF MS for direct identification of bacteria from aqueous environments or positive blood culture samples.
View Article and Find Full Text PDFMacromolecules
January 2025
Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77840, United States.
This work explored solution properties of linear and star poly(methacrylic acids) with four, six, and eight arms (PMAA, 4PMAA, PMAA, and 8PMAA, respectively) of matched molecular weights in a wide range of pH, salt, and polymer concentrations. Experimental measurements of self-diffusion were performed by fluorescence correlation spectroscopy (FCS), and the results were interpreted using the scaling theory of polyelectrolyte solutions. While all PMAAs were pH sensitive and showed an increase in hydrodynamic radius ( ) with pH in the dilute regime, the of star polymers (measured at basic pH values) was significantly smaller for the star polyacids due to their more compact structure.
View Article and Find Full Text PDFAnal Chem
January 2025
Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Straße 11, D-44139 Dortmund, Germany.
The identification of polar and neutral lipid species as biomarkers in complex biological samples is a key task in clinical and life sciences. Electrospray and plasma-based ionization techniques are necessary to cover the full range of lipidomes, owing to their limited molecular polarity ranges. However, combining both to generate hybrid spectra is difficult without averaging spectra, as electrospray and plasma sources operate under vastly different conditions.
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