Newborn screening is performed using modern tandem mass spectrometry, which can simultaneously detect a variety of analytes, including several amino acids and fatty acids. Tandem mass spectrometry measures the diagnostic parameters as absolute concentrations and produces fragments which are used as markers of specific substances. Several prominent quotients can also be derived, which are quotients of two absolute measured concentrations. In this study, we determined the precision of both the absolute concentrations and the derived quotients. First, the measurement error of the absolute concentrations and the measurement error of the ratios were practically determined. Then, the Gaussian theory of error calculation was used. Finally, these errors were compared with one another. The practical analytical accuracies of the quotients were significantly higher (e.g., coefficient of variation (CV) = 5.1% for the phenylalanine to tyrosine (Phe/Tyr) quotient and CV = 5.6% for the Fisher quotient) than the accuracies of the absolute measured concentrations (mean CVs = 12%). According to our results, the ratios are analytically correct and, from an analytical point of view, can support the absolute values in finding the correct diagnosis.
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http://dx.doi.org/10.1007/s00216-017-0179-z | DOI Listing |
Phytochemistry
March 2025
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, People's Republic of China; Zhongyuan Research Center, Chinese Academy of Agricultural Sciences, Xinxiang 453000, People's Republic of China. Electronic address:
Higginsianin F (1), a previously undescribed diterpenoid α-pyridone skeleton featuring a unique N-hydroxyethyl-3-(5-acetyl-4-hydroxy)-α-pyridone ring, along with three undescribed diterpenoid pyrones, higginsianins G-I (2-4), were isolated from the mycelium of the phytopathogenic fungus Colletotrichum higginsianum. Their structures were elucidated through comprehensive analysis using NMR, HRESIMS, and ECD experiments. The absolute configuration of compound 2 was determined to be opposite to the other three compounds based on ECD experiments and the measured optical rotation value.
View Article and Find Full Text PDFEnviron Res
March 2025
School of Chemistry and Chemical Engineering, and Key Laboratory of Environmental Monitoring and Pollutant Control of Xinjiang, Shihezi University, Shihezi, Xinjiang 832003, P. R. China. Electronic address:
Iodine plays a key role in atmospheric chemistry that can significantly affect the atmospheric oxidation capacity. Although the oceans are the main reservoir of iodine on Earth, iodine is also widely present in the terrestrial environment. Therefore, a comprehensive understanding of the present sources of iodine in inland areas is warranted for the evaluation of its environmental effect.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
March 2025
Department of Metabolic Medicine, Faculty of Life Sciences, Kumamoto University. 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.
Context: In 2023, we employed Dexcom G6 for real-time continuous glucose monitoring (rt-CGM); it showed high usefulness but unsatisfactory accuracy in type 1 diabetes summer camp (camp) participants.
Objective: To assess the usefulness, recommendation and accuracy of a new rt-CGM system in camp, 2024.
Methods: Sensor glucose (SG) concentrations were measured by Dexcom G7 (G7) from 6 days prior to camp.
Biomed Chromatogr
April 2025
NMPA Key Laboratory for Research and Evaluation of Drug Metabolism & Guangdong Provincial Key Laboratory of New Drug Screening & Guangdong-Hongkong-Macao Joint Laboratory for New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
Compound 13b, a newly identified anthraquinone derivative, has demonstrated potent efficacy against the Zika virus. To explore the bioavailability and pharmacokinetic properties of compound 13b, a robust and sensitive HPLC-MS/MS method was established and verified to determine its plasma concentration in rats. Sample preparation involved protein precipitation using acetonitrile with testosterone as an internal standard.
View Article and Find Full Text PDFSci Rep
March 2025
Department of Pharmacognosy, College of Pharmacy, King Khalid University, Abha, 62529, Saudi Arabia.
This study investigates the utilization of three regression models, i.e., Kernel Ridge Regression (KRR), nu-Support Vector Regression ([Formula: see text]-SVR), and Polynomial Regression (PR) for the purpose of forecasting the concentration (C) of a drug within a specified environment, relying on the coordinates (x and y).
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