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isotopedilutiontechnique, etc ; analytical chemistry; atomic absorption spectrometry; calibration; fractionation; quantitative analysis; Show all 6 Subjects
Abstract:
... Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has attracted attentions for its high sensitivity and sufficient spatial resolution in the in-situ analysis and imaging in biological studies. However, due to the matrix effect and elemental fractionation, achieving quantitative analysis of elements or proteins in biological samples are still challenging. Calibration is a nece ...
isotopedilutiontechnique, etc ; Gambierdiscus; ciguatera; ciguatoxin; metabolism; pH; sodium borohydride; solvents; Caribbean; Show all 9 Subjects
Abstract:
... Ciguatoxins (CTXs) and gambierones are ladder-shaped polyethers associated with ciguatera poisoning and Gambierdiscus spp. Several of these compounds contain carbonyl or hemiketal groups, which have the potential to exchange with ¹⁸O-labeled water under acidic conditions. The effects of solvent composition and acid on the rate of exchange and on the stability of the labels at various pH values wer ...
isotopedilutiontechnique, etc ; cultivars; flavor; grapes; odors; research; rootstocks; stable isotopes; vigor; wines; Show all 10 Subjects
Abstract:
... BACKGROUND AND AIMS: ‘Green’ sensory characters in Shiraz wines were observed in wines produced from different rootstocks. The compounds responsible were investigated as these attributes are generally seen as negative. METHODS AND RESULTS: GC/MS‐olfactometry and stable isotope dilution analysis methods were used to identify and quantify a range of volatile compounds associated with ‘green’ sensory ...
isotopedilutiontechnique, etc ; blood serum; humans; isotopes; liquid chromatography; mass spectrometry; models; thyroxine; uncertainty; Show all 9 Subjects
Abstract:
... The rigorous and reasonable evaluation of uncertainty is crucial for the reliability of the results of a reference measurement procedure. A new uncertainty budget is proposed for uncertainty evaluation of a reference measurement procedure for total thyroxine in human serum based on isotope dilution liquid chromatography-mass spectrometry. In this work, a measurement model for uncertainty evaluatio ...
isotopedilutiontechnique, etc ; bitterness; enantiomers; lignans; organic chemistry; stable isotopes; stereochemistry; stereoselective synthesis; taste; Show all 9 Subjects
Abstract:
... Lyoniresinol and its derivatives are lignans which have been isolated from a plethora of plant species. In addition to exhibiting a range of interesting biological activities including anticancer, anti-inflammatory, antimicrobial, and others, these compounds have also been discovered in wines and spirits and shown to have gustatory effects in these alcoholic matrices. (+)-Lyoniresinol 1 is reporte ...
isotopedilutiontechnique, etc ; environmental science; gel chromatography; organic matter; risk assessment; stable isotopes; technology; toxicity; Show all 8 Subjects
Abstract:
... The environmental mobility of Cu and therefore its potential toxicity are closely linked to its attachment to natural organic matter (NOM). Geochemical models assume full lability of metals bound to NOM, especially under strong oxidizing conditions, which often leads to an overestimation of the lability of soil metals. Stable isotope dilution (SID) has been successfully applied to estimate the lab ...
Stephen A. Wise; Johanna E. Camara; Carolyn Q. Burdette; Grace Hahm; Federica Nalin; Adam J. Kuszak; Joyce Merkel; Ramón A. Durazo-Arvizu; Emma L. Williams; Andrew N. Hoofnagle; Fiona Ivison; Ralf Fischer; Jody M. W. van den Ouweland; Chung S. Ho; Emmett W. K. Law; Jean-Nicolas Simard; Renaud Gonthier; Brett Holmquist; Sarah Meadows; Lorna Cox; Kimberly Robyak; Michael H. Creer; Robert Fitzgerald; Michael W. Clarke; Norma Breen; Pierre Lukas; Étienne Cavalier; Christopher T. Sempos
isotopedilutiontechnique, etc ; analytical chemistry; blood serum; liquid chromatography; metabolites; regression analysis; tandem mass spectrometry; Show all 7 Subjects
Abstract:
... An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of liquid chromatography – tandem mass spectrometry (LC-MS/MS) assays used for the determination of serum total 25-hydroxyvitamin D (25(OH)D), which is the sum of 25-hydroxyvitamin D₂ (25(OH)D₂) and 25-hydroxyvitamin D₃ (25(OH)D₃). A set of 50 single-donor samples was assigne ...
isotopedilutiontechnique, etc ; blood serum; chlorides; derivatization; humans; reversed-phase liquid chromatography; tandem mass spectrometry; urine; Show all 8 Subjects
Abstract:
... The determination of amino acids in biological samples is central to the diagnosis of inherited metabolic disorders and also gives significant information about the metabolisms in the cells and living body. The development of analytical method for reliable quantification of amino acids in biological samples is still challenging because of the polar nature of amino acids and complex nature of biolo ...
isotopedilutiontechnique, etc ; acetonitrile; amino acids; digestion; fibrinolysis; humans; liquid chromatography; mass spectrometry; reference standards; traceability; Show all 10 Subjects
Abstract:
... Measurement of Thrombin-activatable fibrinolysis inhibitor (TAFI) in human plasma is dependent on reproducible assays. To date, standards for measuring TAFI are frequently calibrated relative to pooled normal human plasma and arbitrarily assigned a potency of 100% TAFI, despite variation in TAFI concentrations between plasma pools. Alternatively, TAFI calibrators can be assigned a value in SI unit ...
isotopedilutiontechnique, etc ; Escherichia coli; butyrates; cell proliferation; fermentation; isotope labeling; mass spectrometry; metabolomics; stable isotopes; Show all 9 Subjects
Abstract:
... The production of chemicals and fuels from renewable resources using engineered microbes is an attractive alternative for current fossil-dependent industries. Metabolic engineering has contributed to pathway engineering for the production of chemicals and fuels by various microorganisms. Recently, dynamic metabolic engineering harnessing synthetic biological tools has become a next-generation stra ...
Jane S. Burns; Oleg Sergeyev; Mary M. Lee; Paige L. Williams; Lidia Mínguez-Alarcón; Bora Plaku-Alakbarova; Sergey Sokolov; Sergey Kovalev; Holger M. Koch; Albert T. Lebedev; Russ Hauser; Susan A. Korrick; for the Russian Children's Study
isotopedilutiontechnique, etc ; boys; genitalia; hormone antagonists; males; medical history; metabolites; phthalates; puberty; research; specific gravity; testes; urine; Show all 13 Subjects
Abstract:
... Although phthalate exposures have been associated with adverse effects on male reproductive health, few studies have explored longitudinal associations with male pubertal development. We examined the association of prepubertal urinary concentrations of phthalate metabolites with age at pubertal onset in a prospective cohort of Russian boys. At enrollment at ages 8–9 years, medical history, dietary ...
Amanda Suárez Fernández; Adriana González Gago; Francisco Artime Naveda; Javier García Calleja; Anna Zawadzka; Zbigniew Czarnocki; Juan Carlos Mayo Barrallo; Rosa M. Sainz Menéndez; Pablo Rodríguez-González; J. Ignacio García Alonso
isotopedilutiontechnique, etc ; cell culture; humans; ionization; isotope labeling; liquid chromatography; melatonin; metabolites; prostatic neoplasms; tandem mass spectrometry; Show all 10 Subjects
Abstract:
... We evaluate here different analytical strategies for the chromatographic separation and determination of N-acetyl-5-methoxytryptamine (MEL) and its oxidative metabolites N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), N1-acetyl-5-methoxykynuramine (AMK) and cyclic 3-hydroxymelatonin (c3OHM) in cell culture samples. Two dimensional liquid chromatography (2D-LC) in the multiple heart-cutting mode wa ...
isotopedilutiontechnique, etc ; Alternaria; altenuene; barley; chemical species; liquid chromatography; malt; research; stable isotopes; tandem mass spectrometry; tenuazonic acid; Show all 11 Subjects
Abstract:
... A liquid chromatography tandem mass spectrometry (LC–MS/MS) multi-mycotoxin method was developed for the analysis of the Alternaria toxins alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), altertoxin I (ATX I), altertoxin II (ATX II), alterperylenol (ALTP), and altenuene (ALT), as well as the modified toxins AOH-3-glucoside (AOH-3-G), AOH-9-glucoside (AOH-9-G), AME-3-glucoside ...
isotopedilutiontechnique, etc ; analytical chemistry; atomic absorption spectrometry; blood serum; digestion; drugs; humans; lanthanum; lithium; mass spectrometry; therapeutics; toxicity; wavelengths; Show all 13 Subjects
Abstract:
... The therapeutic dose of lithium (Li) compounds, which are widely used for the treatment of psychiatric and hematologic disorders, is close to its toxic level; therefore, drug monitoring protocols are mandatory. Herein, we propose a fast, simple, and low-cost analytical procedure for the traceable determination of Li concentration in human serum, based on the monitoring of the Li isotope dilution t ...
isotopedilutiontechnique, etc ; analytical chemistry; carcinogenicity; chemical safety; gas chromatography-mass spectrometry; quality control; reference standards; rubber; stable isotopes; Germany; Show all 10 Subjects
Abstract:
... Polycyclic aromatic hydrocarbons (PAHs) are a large group of priority organic pollutants, which contaminate environmental compartments, food, and consumer products as well. Due to their frequent occurrence associated with elevated levels of PAHs, plastic and rubber parts of consumer products and toys are particular sources of exposure. Although European maximum levels exist for eight carcinogenic ...
isotopedilutiontechnique, etc ; analytical chemistry; blood serum; estriol; humans; immunoassays; liquid chromatography; medicine; metrology; tandem mass spectrometry; traceability; uncertainty; China; Show all 13 Subjects
Abstract:
... To solve long-term lack of traceability of commercial calibrator kits and standardize clinical routine assays, we developed a human serum matrix-based unconjugated estriol (uE3) reference material (RM) with five concentration gradients. The RMs of uE3 were certified by the National Institute of Metrology (NIM) with the codes of GBW (E) 091048, GBW (E) 091049, GBW (E) 091050, GBW (E) 091051, and GB ...
... This study aimed to investigate the role of arbuscular mycorrhizal (AM) fungi on biological N fixation in Vachellia seyal and transfer of fixed N₂ from V. seyal to intercropped Sporobolus robustus under greenhouse conditions. Both plants were grown individually in pots to prevent root contact (“Solid barrier” treatment) or together in two-compartment containers delimited by a plexiglass plate with ...
... East African lakes include the most productive and alkaline lake group in the world. Yet, they generally receive fewer nutrient inputs than the densely populated subtropical and temperate lakes in the northern hemisphere. In these lakes with insufficient supplies of inorganic nitrogen, the mineralization of benthic organic matter can play an important role in driving the nutrient cycle and nitroge ...
isotopedilutiontechnique, etc ; albumins; analytical chemistry; anion exchange; atomic absorption spectrometry; blood serum; clinical trials; copper; drugs; high performance liquid chromatography; humans; quality control; ultrafiltration; Show all 13 Subjects
Abstract:
... Exchangeable copper (CuEXC), mainly comprised copper (Cu) bound to albumin, has been proposed as a specific marker of Cu overload in Wilson’s disease (WD). To the author’s knowledge, there are no methods capable of determining reliably CuEXC to meet the requirements and challenges faced by a clinical trial. The present work describes a novel speciation strategy for the determination of the main Cu ...
Haoran Zhuo; Huang Huang; Andreas Sjodin; Lan Jin; Shuangge Ma; Hristina Denic-Roberts; Joshua L. Warren; Richard Jones; Mark Davis; Peiyuan Sun; Herbert Yu; Mary H. Ward; Robert Udelsman; Yawei Zhang; Jennifer A. Rusiecki
isotopedilutiontechnique, etc ; Bayesian theory; bioaccumulation; blood serum; case-control studies; dose response; gas chromatography; histology; mass spectrometry; models; regression analysis; research; risk; thyroid neoplasms; Show all 14 Subjects
Abstract:
... Although polychlorinated biphenyls (PCBs) were banned decades ago, populations are continuously exposed to PCBs due to their persistence and bioaccumulation/biomagnification in the environment. Results from limited epidemiologic studies linking PCBs to thyroid cancer have been inconclusive. This study aimed to investigate the association between individual PCBs and PCB mixture and papillary thyroi ...