Action spectroscopy with inert gas messengers is commonly used for the characterization of aggregates in the gas phase. The messengers, often rare gas atoms or D molecules, are attached to the gas phase aggregates at low temperature. Vibrational spectra of the aggregates are measured via detection of inert gas desorption following a vibrational excitation by variable-energy infrared light. We have constructed an apparatus for the application of action spectroscopy to surfaces of solids with the aim of establishing a new method for the vibrational spectroscopy of surfaces and deposited clusters. Experiments performed for neon covered VO(0001) show that this method can provide information about surface vibrations. Besides the surface sensitive channel, there is also a bulk sensitive one as demonstrated with the example of CeO(111) thin film data. Unlike infrared reflection absorption spectroscopy, normalization to a reference spectrum is not required for action spectroscopy data, and unlike high resolution electron energy loss spectroscopy, the action spectroscopy method does not suffer from moderate resolution nor from multiple excitations. Selective decoration of specific surface features with messenger atoms may be utilized to focus the spectroscopic information onto these features.
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Materials (Basel)
December 2024
Fraunhofer WKI, 38108 Braunschweig, Germany.
Despite its importance, the determination of the degree of cure of melamine-based laminates often relies on tests with limited accuracy and validity. Undercured surfaces may suffer insufficient resistance to scratching and heat as well as substandard surface quality. Overcured melamine surfaces tend to crack and entail the inefficient utilization of the press-the panels could have been pressed for a shorter time.
View Article and Find Full Text PDFMolecules
December 2024
Institute for Biological Systems, Italian National Research Council, Monterotondo, 00015 Rome, Italy.
Rising temperatures due to climate change may affect the quality of open-field cultivated processing tomatoes by altering the nutrient content. Bioinoculants are growing in popularity as a nature-based strategy to mitigate these environmental stresses. Untargeted quantitative NMR spectroscopy was leveraged to characterize the metabolome of tomato fruits exposed to abiotic stress during the year 2022, which was marked by unexpected high temperatures and low rainfall compared to the year 2021 with average conditions.
View Article and Find Full Text PDFJ Adv Res
January 2025
State Key Laboratory of Chemical Biology and Drug Discovery and the Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; Shenzhen Key Laboratory for Food Biological Safety Control, Food Safety and Technology Research Centre, The Hong Kong PolyU Shenzhen Research Institute, Shenzhen, PR China. Electronic address:
Introduction: Infections stemming from multidrug-resistant bacteria present a substantial threat to public health today. Discovering or synthesizing novel compounds is crucial to alleviate this pressing situation.
Objective: The main purpose of this study is to verify the antibacterial activity of LTX-315 and explore its primary action mode.
Proc Natl Acad Sci U S A
January 2025
Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390.
Neurotransmitter release is triggered in microseconds by Ca-binding to the Synaptotagmin-1 C-domains and by SNARE complexes that form four-helix bundles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca-sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker zippering) and binding of the Synaptotagmin-1 CB domain to SNARE complexes through a "primary interface" comprising two regions (I and II). The Synaptotagmin-1 Ca-binding loops were believed to accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers, or helping bridge the membranes, but SNARE complex binding through the primary interface orients the Ca-binding loops away from the fusion site, hindering these putative activities.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
In this work, coixalkyne A (), a natural polynuclear calcium complex with a novel cross-shaped molecular architecture, was isolated from L. along with the undescribed analogue coixalkyne B (). Their structures were identified by means of NMR spectroscopy, ECD calculations, and single-crystal X-ray diffraction.
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