Search results for "LIMIT"
showing 10 items of 2826 documents
A new upper limit of the electron anti neutrino rest mass from tritium β-decay
1993
Abstract A new upper limit of the electron anti neutrino rest mass has been deduced from the tritium β-decay spectrum. A source of molecular tritium has been investigated with a new solenoid retarding spectrometer. The results are m ν ϵ 2 = −38.8 ± 34.1 stat ± 15.1 syst (eV) 2 /c 4 from which we conclude m ν ϵ ≤ 7.2 eV/c 2 with 95% c.l. Our β-endpoint corresponds to a 3H-3He atomic mass difference of Δm( 3 H- 3 He) = 18590.8 ± 3 eV/c 2 (1σ) .
On the numerical solution of axisymmetric domain optimization problems by dual finite element method
1994
Shape optimization of an axisymmetric three-dimensional domain with an elliptic boundary value state problem is solved. Since the cost functional is given in terms of the cogradient of the solution, a dual finite element method based on the minimum of complementary energy principle is used. © 1994 John Wiley & Sons, Inc.
Impact of Aortic Diameter Measurements at Three Anatomical Landmarks on Left Ventricular Output Calculation in Neonates
2021
OBJECTIVES To assess reproducibility and accuracy of left ventricular output (LVO) quantifications in neonates, when left ventricular outflow tract diameter (LVOTD) was measured at the hinges of the aortic valve (AV), at the aortic sinus (AS), and at the sinotubular junction (STJ). METHODS This was an observational study. In the first cohort of very preterm neonates, we assessed intraobserver and interobserver repeatability of LVOTD measured at the AV, AS, and STJ and of the corresponding LVO. In the second cohort of older neonates, we compared paired LVO measurements by echo and magnetic resonance imaging (MRI). RESULTS In the first cohort of 48 neonates, mean (standard deviation) weight a…
Perceived barriers in the outdoor environment and development of walking difficulties in older people
2012
SIR—Older people with mobility limitations often report more barriers in their outdoor environment than people with intact mobility [1]. However, it is uncertain whether older people perceive their environment as problematic because of their mobility limitations or whether the environmental barriers precede incident mobility limitation, as most studies have been limited to cross-sectional analyses [2–5]. Only a few longitudinal studies have shown that barriers in the outdoor environment, such as poor street conditions, poor lighting and heavy traffic, increase the risk for overall functional loss [6, 7] and decrease physical activity participation [8]. More knowledge is needed about the cha…
Life-Space Mobility in Parkinson's Disease: Associations with Motor and Non-Motor Symptoms.
2019
Background To describe life-space mobility and explore associations of motor and non-motor symptoms with life-space mobility in people with Parkinson’s disease (PD). Methods About 164 community-dwelling persons with PD (mean age 71.6 years, 64.6% men) received a postal survey and a subsequent home visit. Motor assessments included perceived walking difficulties (Walk-12G), mobility (Timed Up and Go test), motor symptoms (UPDRS-III), and freezing of gait (item 3, FOG-Qsa). Non-motor symptoms included depressive symptoms (GDS-15), pain, fatigue (NHP-EN), and global cognition (MoCA). Life-space mobility was assessed with the life-space assessment (LSA). Calculations included composite score (r…
Bioaccessibility of Deoxynivalenol and its natural co-occurrence with Ochratoxin A and Aflatoxin B1 in Italian commercial pasta
2012
Abstract Cereals products for direct human consumption are rarely contaminated by moulds, unlike raw materials, which are often infected, either in the field or during storage. In this study, 27 samples of dried pasta characterised by size, packaging and marketing intended for young children consumption were collected and analysed by liquid chromatography (LC) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for Deoxynivalenol (DON), Ochratoxin A (OTA) and Aflatoxin B 1 (AFB 1 ) determination. The samples that showed the highest amounts of one of the mycotoxins were cooked for 10 min, digested with an in vitro gastrointestinal protocol and bioaccessibility values were calculate…
Application of hybrid linear ion trap-high resolution mass spectrometry to the analysis of mycotoxins in beer
2011
This paper reports the application of liquid chromatography electrospray ionization ion trap-orbitrap mass spectrometry for the determination of 18 mycotoxins (aflatoxins, fumonisins, trichothecenes, ochratoxin A, sterogmatocystin, beauvaricin, zearalenone and zearalenol) in beer. The extraction procedure was carried out by solid phase extraction (SPE): SPE columns were conditioned with acetonitrile/methanol and water. Beer was loaded onto the column which was washed with water. In these conditions, the recoveries were more than 65% and the relative standard deviation (RSD) were below 18%. The lowest limits of quantification (LLOQ) ranged from 9 to 155 ng ml(-1). Matrix-matched calibration …
Ochratoxin A in the morning and afternoon portions of urine from Coimbra and Valencian populations.
2008
Abstract The widespread contamination of foodstuffs and beverages by mycotoxins, such as ochratoxin A (OTA), has made the monitoring of human contamination levels essential. By using a sensitive, accurate and speedy method that combines extraction with 5% NaHCO 3 , immunoaffinity column clean-up and HPLC with fluorescence detection, the human exposure to OTA through urine analysis can be monitored. This method is less invasive than blood monitoring and has the potential to be a good marker of human exposure. The limit of quantification of the method was 0.007 ng/mL of urine, with recoveries of OTA, from urine samples spiked at levels between 0.02 and 0.1 ng/mL, higher than 91% with RSD lowe…
Quantitative determination of ochratoxin A in vegetable foods
1982
A simple method for the quantitative determination of ochratoxin A (OA) in rice and other vegetable foods (oatmeal, coconut flakes and peas) is described. This procedure implies an acetonitrile-4% KCl -6N HCl (88+10+2) extraction of the acidic OA, subsequent twodimensional thin-layer chromatography (TLC) and detection by fluorescence after exposure to ammonia fumes (excitation at 340 nm; emission at 475 nm). The quantitative detection limit for OA in rice or coconut flakes is 2.4–4 μg/kg and the recovery is 96%. For oatmeal and peas the detection limit is only 20 μg/kg because of the interference by other metabolites.
Pressurized liquid extraction coupled to liquid chromatography for the analysis of ochratoxin A in breakfast and infants cereals from Morocco
2010
Abstract A sensitive and reliable method using pressurized liquid extraction (PLE) and liquid chromatography (LC) has been developed for the analysis of ochratoxin A (OTA) in breakfast and infants cereals. Influence of several extraction solvents that affect PLE efficiency was studied. The selected PLE operating method was: 10 g of sample was packed into 22 ml stainless-steel cell and OTA was extracted with acetonitrile/water (80:20) at 40 °C, 34 atm in one cycle of 5 min at 60% flush. The mean recovery of OTA was 82 ± 4 at fortification level of 3 ng/g OTA. The limit of quantification (LOQ) of OTA was 0.25 ng/g. The proposed method was successfully applied to the analysis of 68 samples of …