Fermentation-derived short-chain fatty acids (SCFA) are potential mediators of the health benefits associated with dietary fiber intake. SCFA affect physiological processes locally in the gut and on distant organs via the systemic circulation. Since SCFA are used as energy source for colonocytes and substrate for the liver metabolism, their concentrations in the systemic circulation are low. Therefore, quantification of systemic SCFA requires sensitive analytical techniques. This article covers the optimization and validation of a gas chromatography-mass spectrometry method to measure systemic SCFA concentrations following derivatization with 2,4-difluoroaniline (DFA) and extraction in ethyl acetate. Sample preparation was optimized by varying the amount of DFA, coupling agent 1,3-dicyclohexylcarbodiimide, ethyl acetate and sodium bicarbonate, which is used to quench derivatization. In addition, evaporation of the samples using a vacuum concentrator resulted in less contamination, notably of acetate, compared to drying with N gas. The method showed excellent linearity with coefficient of variation (R) > 0.99 and a good precision (relative standard deviation < 20 %) and accuracy. Finally, systemic concentrations of SCFA in human plasma samples could successfully be determined.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jchromb.2024.124299 | DOI Listing |
Eur Radiol
January 2025
Department of Radiology, Montpellier Research Center Institute, PINKCC Laboratory, Montpellier, France.
Objective: To provide up-to-date European Society of Urogenital Radiology (ESUR) guidelines for staging and follow-up of patients with ovarian cancer (OC).
Methods: Twenty-one experts, members of the female pelvis imaging ESUR subcommittee from 19 institutions, replied to 2 rounds of questionnaires regarding imaging techniques and structured reporting used for pre-treatment evaluation of OC patients. The results of the survey were presented to the other authors during the group's annual meeting.
Clin Transl Sci
January 2025
Global Biometrics and Data Management, Pfizer Research and Development, New York, New York, USA.
The pharmaceutical industry constantly strives to improve drug development processes to reduce costs, increase efficiencies, and enhance therapeutic outcomes for patients. Model-Informed Drug Development (MIDD) uses mathematical models to simulate intricate processes involved in drug absorption, distribution, metabolism, and excretion, as well as pharmacokinetics and pharmacodynamics. Artificial intelligence (AI), encompassing techniques such as machine learning, deep learning, and Generative AI, offers powerful tools and algorithms to efficiently identify meaningful patterns, correlations, and drug-target interactions from big data, enabling more accurate predictions and novel hypothesis generation.
View Article and Find Full Text PDFObjective: To determine if surgical skills instructors' experience and qualifications influence students' learning of small animal ovariohysterectomy on a model (mOVH).
Sample Population: Second-year veterinary students (n = 105).
Methods: Students were randomized to three groups, taught by: (1) residency-trained surgeons with over 3 years' experience teaching mOVH, (2) general practitioners with over 3 years' experience teaching mOVH (GP >3), and (3) general practitioners with under 3 years' experience (GP <3).
Adv Mater
January 2025
Liquid Crystals and Photonics Group, Department of Electronics and Information Systems, Ghent University, Technologiepark-Zwijnaarde 126, Ghent, 9052, Belgium.
In liquid crystal (LC) cells, the surface patterning directs the self-assembly of the uniaxial building blocks in the bulk, enabling the design of stimuli-response optical devices with various functionalities. The combination of different anchoring patterns at both substrates can lead to surface induced frustration, preventing a purely planar and defect-free configuration. In cells with crossed assembly of rotating anchoring patterns, elastic deformations allow to obtain a defect-free bulk configuration, but an electrical stimulus can induce disclination lines.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, 116024, China.
To achieve efficient size tuning of printed microstructures on insulating substrates, an integrated process parameter intelligent optimization design framework for alternating current pulse modulation electrohydrodynamic (AC-EHD) printing is proposed for the first time. The framework is comprised of two stages: the construction of a prediction model and the acquisition of process parameters. The first stage employs the elk herd optimizer(EHO)-artificial neural network(ANN) to establish a mapping relationship between printing process parameters and the size of deposited droplets.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!