Salicylic acid (SA) is a natural phenolic compound known as the active principle of aspirin. Its presence in vegetal sources suggests that fruit and vegetable (FV) consumption could produce ...measurable SA serum concentrations in human subjects not taking aspirin. The aim of this study was to investigate the relationship between FV intake and circulating SA in healthy subjects. Thirty-eight volunteers (twenty-two males and sixteen females) were recruited from an Italian university campus. They recorded their food intake for 7 d to evaluate dietary consumption and, in particular, FV intake; fasting blood samples were taken on the morning of the eighth day to measure SA serum concentration, using a sensitive stable isotope dilution and GC-MS method. Median SA serum concentration was 0.124 micromol/l (range 0.028-0.295). Circulating SA was significantly related to FV consumption, both to the mean daily intake (r2 0.13, P=0.03) and to the last day intake (r2 0.16, P=0.01). The subjects in the highest FV intake quartile in the preceding day (>4.75 servings) had significantly higher SA concentrations than in the lowest quartile (<2.3 servings) (median concentrations 0.188 and 0.112 micromol/l, respectively; P=0.04). This study proved that, after overnight fast, human subjects not taking aspirin display circulating SA in amounts related to the FV consumption. It is therefore possible that the beneficial effects of regular FV consumption in man could also depend on low chronic SA exposure.
A simple, highly selective, and sensitive method using stable isotope dilution and gas chromatography–mass spectrometry has been developed to quantify salicylic acid (SA) at concentrations naturally ...occurring in biological fluids, such as in the serum of subjects not taking aspirin. After extraction of liquid–liquid with diethyl ether and ethyl acetate and preparation of the tert-butyldimethylsilyl derivative, SA content was detected using deuterated SA as internal standard. The mean recovery of SA from serum was 85
±
6%. Intra- and interday precision and % relative error were <15% in all cases.With a detection limit of 0.6
ng and a quantification limit of 2
ng, the method is therefore also adequate for population studies because of the small amount of blood necessary to perform the analyses.
DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3279 kg of LAr contained in a ...spherical acrylic vessel. This paper reports on the analysis of a 758 tonne·day exposure taken over a period of 231 live-days during the first year of operation. No candidate signal events are observed in the WIMP-search region of interest, which results in the leading limit on the WIMP-nucleon spin-independent cross section on a LAr target of 3.9×10−45 cm2 (1.5×10−44 cm2) for a 100 GeV/c2 (1 TeV/c2) WIMP mass at 90% C.L. In addition to a detailed background model, this analysis demonstrates the best pulse-shape discrimination in LAr at threshold, employs a Bayesian photoelectron-counting technique to improve the energy resolution and discrimination efficiency, and utilizes two position reconstruction algorithms based on the charge and photon detection time distributions observed in each photomultiplier tube.
The WARP programme is a graded programme intended to search for cold dark matter in the form of weakly interacting massive particles. These particles may produce via weak interactions nuclear recoils ...in the energy range 10–100 keV. A cryogenic noble liquid like argon, already used in the realization of very large detector, permits the simultaneous detection of both ionization and scintillation induced by an interaction, suggesting the possibility of discriminating between nuclear recoils and electrons mediated events. A 2.3
l two-phase argon detector prototype has been used to perform several tests on the proposed technique. Next step is the construction of a 100
l sensitive volume device with potential sensitivity a factor 100 better than presently existing experiments.
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