Primary-ion-induced fragmentation in organic molecules can strongly influence the results in secondary-ion mass spectrometry (SIMS) of organic and biomolecular samples. In order to characterize this ion-induced fragmentation, oligopeptide samples irradiated in SIMS experiments were investigated by means of desorption/ionization induced by neutral SO clusters (DINeC). The latter is a nondestructive desorption method for mass spectrometry of biomolecules, which gives direct access to the fragments induced in the sample. Comparison of TOF-SIMS and DINeC mass spectra revealed qualitative differences between the fragments, which remain in the sample and the fragments sputtered during ion bombardment. The fragmentation strength and its spatial distribution were found to be quantitatively different for Bi, Bi, and Ar primary ions, leading to different distributions of the degree of fragmentation in the samples as directly measured by means of DINeC depth profiles.
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http://dx.doi.org/10.1021/acs.analchem.0c03765 | DOI Listing |
Plant Cell Environ
January 2025
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Nitrate reduction requires reducing equivalents produced by the photosynthetic electron transport chain. Therefore, it has been suggested that nitrate assimilation provides a sink for electrons under high light conditions. We tested this hypothesis by monitoring photosynthetic efficiency and the chloroplastic glutathione redox potential (chl-E) of plant lines with mutated glutamine synthetase 2 (GS2) and ferredoxin-dependent glutamate synthase 1 (GOGAT1).
View Article and Find Full Text PDFBMC Plant Biol
January 2025
Key Laboratory of Biology and Genetic Improvement of Oil Crops of the Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
Background: Perilla frutescens (L.) Britt. (Lamiaceae) leaves are essential culinary and medicinal herbs, native to East Asian countries.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
Chemical Sciences Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA.
Commutability is where the measurement response for a reference material (RM) is the same as for an individual patient sample with the same concentration of analyte measured using two or more measurement systems. Assessment of commutability is essential when the RM is used in a calibration hierarchy or to ensure that clinical measurements are comparable across different measurement procedures and at different times. The commutability of three new Standard Reference Materials (SRMs) for determining serum total 25-hydroxyvitamin D [25(OH)D], defined as the sum of 25-hydroxyvitamin D [25(OH)D] and 25-hydroxyvitamin D [25(OH)D], was assessed through an interlaboratory study.
View Article and Find Full Text PDFNat Metab
January 2025
Department of Genetics, Stanford University, School of Medicine, Stanford, CA, USA.
The short-chain fatty acids (SCFAs) propionate and butyrate have beneficial health effects, are produced in large amounts by microbial metabolism and have been identified as unique acyl lysine histone marks. To better understand the function of these modifications, we used chromatin immunoprecipitation followed by sequencing to map the genome-wide location of four short-chain acyl histone marks, H3K18pr, H3K18bu, H4K12pr and H4K12bu, in treated and untreated colorectal cancer (CRC) and normal cells as well as in mouse intestines in vivo. We correlate these marks with open chromatin regions and gene expression to access the function of the target regions.
View Article and Find Full Text PDFBiol Trace Elem Res
January 2025
Clinical Research Centre, University Medical Centre Ljubljana, Zaloška Cesta 2, 1000, Ljubljana, Slovenia.
Premature ovarian insufficiency (POI) is poorly understood, with causes identified in only 25% of cases. Emerging evidence suggests links between trace elements (TEs) and POI. This study is the first to compare concentrations of manganese (Mn), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) across urine, serum, and whole blood in women with POI compared to healthy controls (HC), aiming to explore their distribution and potential associations with POI.
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