1,417 research outputs found
Comparison of the toxicokinetics of daidzein and bisphenol A in pregnant and non-pregnant DA/Han rats
Potentially adverse human and environmental effects due to hormone mimicry of environmental estrogens are a matter of current concern. Environmental estrogens belong to the socalled endocrine active compounds (EAC) and may alter signalling processes of the endocrine system leading to a broad range of effects during fetal and postnatal development, puberty, adulthood, and aging. A number of synthetic chemicals as well as several plant-derived compounds, socalled phytoestrogens, are known to have weak estrogenic activity. The present study is part of the risk assessment of the weak environmental estrogens daidzein and bisphenol A. The isoflavone daidzein is an important phytoestrogen with respect to dietary exposure (soy beans and soy products) whereas bisphenol A is an industrial chemical that occurs at much lower concentrations as a contaminant in food. The toxicokinetics of these compounds in female pregnant and non-pregnant DA/Han rats after single intravenous application were compared by the use of the Mann-Whitney- U-statistic. --Bisphenol A,daidzein,xenoestrogens,phytoestrogens,endocrine active compounds,Mann-Whitney-U-test
Guide to holiness and revival miscellany: volume XXIV
https://place.asburyseminary.edu/ecommonsatsdigitalresources/1505/thumbnail.jp
Estimation of the Mean AUC of the Xenoestrogens Daidzein, Bisphenol A, and p-tert-Octylphenol
Potentially adverse human and environmental effects due to hormone mimicry of environmental estrogens are a matter of current concern. Environmental estrogens belong to the so-called endocrine active compounds (EAC), which alter signalling processes of the endocrine system leading to a broad range of effects during foetal and postnatal development, puberty, adulthood, and aging. A number of synthetic chemicals as well as several plant-derived compounds, so-called phytoestrogens, are known to have weak estrogenic activity. The present study is part of the risk assessment of the weak environmental estrogens daidzein, p-tert-octylphenol, and bisphenol A. The isoflavone daidzein is an important phytoestrogen with respect to dietary exposure (soy beans and soy products). p-tert-Octylphenol and bisphenol A are industrial chemicals. The toxicokinetics and the bioavailability of these three substances in female DA/Han rats after oral and single intravenous application were investigated by the use of population models accounting for the differences in the individual metabolism. Furthermore, populations of pregnant and non-pregnant rats are compared
Elastometry of deflated capsules elastic moduli from shape and wrinkle analysis
Elastic capsules, prepared from droplets or bubbles attached to a capillary (as in a pendant drop tensiometer), can be deflated by suction through the capillary. We study this deflation and show that a combined analysis of the shape and wrinkling characteristics enables us to determine the elastic properties in situ. Shape contours are analyzed and fitted using shape equations derived from nonlinear membrane-shell theory to give the elastic modulus, Poisson ratio and stress distribution of the membrane. We include wrinkles, which generically form upon deflation, within the shape analysis. Measuring the wavelength of wrinkles and using the calculated stress distribution gives the bending stiffness of the membrane. We illustrate this method on two very different capsule materials: polymerized octadecyltrichlorosilane (OTS) capsules and hydrophobin (HFBII) coated bubbles. Our results are in agreement with the available rheological data. For hydrophobin coated bubbles the method reveals an interesting nonlinear behavior consistent with the hydrophobin molecules having\ud
a rigid core surrounded by a softer shell
Spurious harmonic response of multipulse quantum sensing sequences
Multipulse sequences based on Carr-Purcell decoupling are frequently used for
narrow-band signal detection in single spin magnetometry. We have analyzed the
behavior of multipulse sensing sequences under real-world conditions, including
finite pulse durations and the presence of detunings. We find that these
non-idealities introduce harmonics to the filter function, allowing additional
frequencies to pass the filter. In particular, we find that the XY family of
sequences can generate signals at the 2fac, 4fac and 8fac harmonics and their
odd subharmonics, where fac is the ac signal frequency. Consideration of the
harmonic response is especially important for diamond-based nuclear spin
sensing where the NMR frequency is used to identify the nuclear spin species,
as it leads to ambiguities when several isotopes are present.Comment: 6 pages, 7 figure
Force-detected nuclear double resonance between statistical spin polarizations
We demonstrate nuclear double resonance for nanometer-scale volumes of spins
where random fluctuations rather than Boltzmann polarization dominate. When the
Hartmann-Hahn condition is met in a cross-polarization experiment, flip-flops
occur between two species of spins and their fluctuations become coupled. We
use magnetic resonance force microscopy to measure this effect between 1H and
13C spins in 13C-enriched stearic acid. The development of a cross-polarization
technique for statistical ensembles adds an important tool for generating
chemical contrast in nanometer-scale magnetic resonance.Comment: 14 pages, 4 figure
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