An inter-laboratory trial (ILT) has been performed to validate ISO 21675 method for the measurement of per-and polyfluoroalkyl substances (PFAS) in water samples using solid phase extraction method and high-performance liquid chromatography-tandem mass spectrometry. A total of twenty-seven laboratories from eleven countries (Belgium: 1, Canada: 2, China: 2, France: 1, Germany: 3, Italy: 2, Japan: 6, Netherlands: 2, South Korea: 1, Sweden: 4, and USA: 3) participated in the ILT. Results of the homogeneity of ILT water samples showed that the repeatability tended to increase from short-chain to long-chain of PFAS. Results of stability of PFAS in Milli-Q water stored at 5 ± 3 °C ranged from 75% to 121% including those ultra-short-chain compounds, except for N-MeFOSA (44%), N-EtFOSA (44%), and 8:2 FTOH (30%) at 168 days. As for stability of PFAS in environmental waters, they were in acceptable range (between 70 and 125%) for most of PFAS, except for 8:2 FTUCA in the river water, seawater, and wastewater, and 8:2 FTSA and 8:2 FTOH in wastewater. Based on the performance data (reproducibility (CV): <40%, recoveries (η): 70-125%) of the ILT, current ISO 21675 is validated for up to 30 PFAS depending on water type. Novel analytical techniques namely "In-situ Solid Phase Extraction" and the "Purge and Trap Extraction" were developed and explored to measure volatile PFAS. Preliminary results showed acceptable recoveries for volatile PFAS such as fluorotelomer alcohols and iodides in spiked Milli-Q water.
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http://dx.doi.org/10.1016/j.chemosphere.2021.132440 | DOI Listing |
Alzheimers Dement
December 2024
Yonsei University, Incheon, Incheon, Korea, Republic of (South).
Background: Cyclin Y (CCNY) is a member of cyclin protein family inhibiting long-term synaptic plasticity, which is related to the learning and memory function in neuronal system. Recently, CCNY has been reported to associate with the cognitive deficits in Alzheimer's disease (AD).
Method: In this study, we discovered PFTAIRE peptide to diminish CCNY protein level and to ameliorate cognitive dysfunction in AD.
Alzheimers Dement
December 2024
Yonsei University, Incheon, Incheon, Korea, Republic of (South).
Background: As amyloid-β (Aβ) aggregates are considered as the biomarkers and key factors in the pathology of Alzheimer's disease, there has been extensive investigation into Aβ-targeting compounds for the development of diagnostics and drug discovery related to the disorder. However, the polymorphic and heterogenous nature of Aβ aggregates impedes the structural understanding of their structure. Consequently it is a major challenge to develop new diagnostic and therapeutic development of AD and to study the mechanism of Aβ-targeting compounds.
View Article and Find Full Text PDFClin Chem Lab Med
January 2025
Laboratory of Clinical Pathology, Azienda Sanitaria Universitaria Integrata, Udine, Italy.
Objectives: External quality assessment (EQA) programs play a pivotal role in harmonizing laboratory practices, offering users a benchmark system to evaluate their own performance and identify areas requiring improvement. The objective of this study was to go through and analyze the UK NEQAS "Immunology, Immunochemistry and Allergy" EQA reports between 2012 and 2021 to assess the overall level of harmonization in autoimmune diagnostics and identify areas requiring improvement for future actions.
Methods: The EQA programs reviewed included anti-nuclear (ANA), anti-dsDNA, anti-centromere, anti-extractable nuclear antigen (ENA), anti-phospholipids, anti-neutrophil cytoplasm (ANCA), anti-proteinase 3 (PR3), anti-myeloperoxidase (MPO), anti-glomerular basement membrane (GBM), rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), mitochondrial (AMA), liver-kidney-microsomal (LKM), smooth muscle (ASMA), APCA, and celiac disease antibodies.
RSC Chem Biol
December 2024
Department of Chemistry, Texas A&M University College Station Texas 77843 USA
Despite the growing interest in mirror-image l-oligonucleotides, both as a robust nucleic acid analogue and as an artificial genetic polymer, their broader adoption in biochemical research and medicine remains hindered by challenges associated with the synthesis of long sequences, especially for l-RNA. Herein, we present a novel strategy for assembling long l-RNAs the joining of two or more shorter fragments using cross-chiral ligase ribozymes together with new substrate activation chemistry. We show that 5'-monophosphorylated l-RNA, which is readily prepared by solid-phase synthesis, can be activated by chemical attachment of a 5'-adenosine monophosphate (AMP) or diphosphate (ADP), yielding 5'-adenosyl(di- or tri-)phosphate l-RNA.
View Article and Find Full Text PDFChem Sci
December 2024
Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei Anhui 230026 China
The packing of organic molecular crystals is often dominated by weak non-covalent interactions, making their rearrangement under external stimuli challenging to understand. We investigate a pressure-induced single-crystal-to-single-crystal (SCSC) transformation between two polymorphs of 2,4,5-triiodo-1-imidazole using machine learning potentials. This process involves the rearrangement of halogen and hydrogen bonds combined with proton transfer within a complex solid-state system.
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