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81.
M.-L. Bayle C. Enea P. Goetinck F. Lafay N. Boisseau B. Dugué M.-M. Flament-Waton M.-F. Grenier-Loustalot 《Analytical and bioanalytical chemistry》2009,393(4):1315-1325
Dehydroepiandrosterone (DHEA) and its metabolite androsterone (A) are natural steroids secreted in high quantities in human
body. To assess the influence of oral contraceptives, menstrual cycle phase, and also physical exercise (acute and chronic
such as training) on these metabolites excretions, a collection of 28 female urine specimens was organized. A three-extraction-step
method was developed, and the analyses were performed by gas chromatography–mass spectrometry using deuterated 19-noretiocholanolone
as the internal standard. Sample hydration state was found to be of great importance for kinetic studies, as it directly influenced
the concentrations. No influence of menstrual cycle and training was found for androsterone and DHEA. However, oral contraceptive
intake lowered DHEA excretion in urine and A seems to be slightly affected by exercise. 相似文献
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84.
D’Ulivo Lucia Pagliano Enea Onor Massimo Mester Zoltan D’Ulivo Alessandro 《Analytical and bioanalytical chemistry》2019,411(8):1569-1578
Analytical and Bioanalytical Chemistry - In order to elucidate controversial results emerging in chemical vapor generation (CVG) for trace element determination, we conducted a series of... 相似文献
85.
A simple group theoretic derivation is given of the family of space-time metrics with isometry group SO(2,1) × SO(2) × first described by Gödel, of which the Gödel stationary cosmological solution is the member with a perfect-fluid stress-energy tensor. Other members of the family are shown to be interpretable as cosmological solutions with an electrically charged perfect fluid and a magnetic field. 相似文献
86.
Stability constants of silver complexes with the substituted ligands 2-methyl-2,5-dimethyl-, 2,6-dimethyl-, 2-chloro- and 2-amino-pyrazines are determined by means of a potentiomeric method, using metal complex electrodes at 25°C and 0.1M KNO3 as an ionic strength in aqueous medium.
Standard enthalpies of the two steps of complexation observed are obtained by a direct calorimetric technique (except for the Ag-2-aminopyrazine system whose complexes are not sufficiently soluble) under the same experimental conditions. The corresponding standard entropies are calculated.
The discussion of the thermodynamic functions takes into account the nature and the position of the substitutents to interprete the coordination ability of each amine. 相似文献
87.
Thermodynamic values for the formation of complexes of Ag+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ ions with hydantoïn were determined at 25°C in aqueous medium 0.5 M KNO3. Stability constants were calculated from pH metric measurements while corresponding standard enthalpies were deduced from direct calorimetric determinations. The results are interpreted and compared to those of succinimide complexes previously studied. 相似文献
88.
Antonio Enea Romano Pisin Chen 《The European Physical Journal C - Particles and Fields》2014,74(4):1-8
We calculate the low-redshift Taylor expansion for the luminosity distance for an observer at the center of a spherically symmetric matter inhomogeneity with a non-vanishing cosmological constant. We then test the accuracy of the formulas comparing them to the numerical calculation for different cases for both the luminosity distance and the radial coordinate. The formulas can be used as a starting point to understand the general non-linear effects of a local inhomogeneity in the presence of a cosmological constant, without making any special assumption as regards the inhomogeneity profile. 相似文献