Search results for "absorption"

Application of pressurized fluid extraction to determine cadmium and zinc in plants

2006

Abstract A procedure for the determination of Cd and Zn in plants is proposed. The metals are extracted by pressurized fluid extraction (PFE). Operational conditions are: pressure 1500 psi, temperature 75 °C, static time 5 min, flush volume 35%, purge time 60 s, cycles 1 and 1,2-diaminocyclohexane- N , N , N ′, N ′-tetraacetic acid (CDTA) 0.01 M at pH 4.5 as extracting solution. Determination of Zn is carried out by flame atomic absorption spectroscopy and depending on the concentration level, Cd content is determined by flame or electrothermal atomic absorption spectroscopy. Certified samples of Virginia tobacco leaves, tea leaves, spinach leaves, poplar leaves, a commercial spinach sample…

Effects of Gestational Diabetes Mellitus on Cholesterol Metabolism in Women with High-Risk Pregnancies: Possible Implications for Neonatal Outcome

2022

Metabolic disorders in pregnancy, particularly gestational diabetes mellitus (GDM), are associated with an increased risk for adverse pregnancy outcome and long-term cardiometabolic health of mother and child. This study analyzed changes of serum cholesterol synthesis and absorption markers during the course of high-risk pregnancies, with respect to the development of GDM. Possible associations of maternal lipid biomarkers with neonatal characteristics were also investigated. The study included 63 women with high risk for development of pregnancy complications. Size and proportions of small low-density (LDL) and high-density lipoprotein (HDL) particles were assessed across trimesters (T1&nd…

Funkcjonalizowane woski polietylenowe jako kompatybilizatory kompozytów polietylenowo-drzewnych o wysokim stopniu napełnienia

2012

Badano proces otrzymywania kompozytów polimerowo-drzewnych o dużym stopniu napełnienia (60-80%), przygotowanych na bazie polietylenu małej gęstości (PE-LD) z udziałem komercyjnej mączki drzewnej (Lignocel C 120 i Arbocel C 320) oraz dodatkiem wosków polietylenowych sfunkcjonalizowanych poprzez ich utlenienie lub szczepienie bezwodnika maleinowego, stosowanych jako czynniki kompatybilizujące. Otrzymane materiały poddano charakterystyce określając ich podstawowe właściwości mechaniczne oraz chłonność wody. Stwierdzono, że nawet niewielka ilość wprowadzonego kompatybilizatora (2,5%), w porównaniu z próbkami otrzymanymi bez jego udziału, w istotny sposób poprawia wytrzymałość kompozytów na zerw…

Bases physiologiques de la satiété et de la digestion

2015

High-contrast sub-Doppler absorption spikes in a hot atomic vapor cell exposed to a dual-frequency laser field

2017

International audience; The saturated absorption technique is an elegant method widely used in atomic and molecular physics for high-resolution spectroscopy, laser frequency standards and metrology purposes. We have recently discovered that a saturated absorption scheme with a dual-frequency laser can lead to a significant sign reversal of the usual Doppler-free dip, yielding a deep enhanced-absorption spike. In this paper, we report detailed experimental investigations of this phenomenon, together with a full in-depth theoretical description. It is shown that several physical effects can support or oppose the formation of the high-contrast central spike in the absorption profile. The physi…

Search for Cosmic Neutrino Point Sources with Four Year Data of the ANTARES Telescope

2012

In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by the ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on the neutrino flux have been obtained. Assuming an E ¿2 n; spectrum, these flux limits are at 1-10 ¿10¿8 GeV cm¿2 s¿1 for declinations ranging from ¿90° to 40°. Limits for specific models of RX J1713.7¿3946 and Vela X, which include information on the source morphology and spectrum, are also given.

Multi-resolution investigations of the methane IR spectrum. At the borderline between modelling state of the art and astrophysical needs

2009

International audience; Remote sensing of the atmosphere of astrophysical objects relies essentially on molecular spectroscopy. Astrophysical investigations generally need both complete and accurate spectroscopic databases. Despite continuous efforts in experimental and theoretical spectroscopic investigations, the lack of data in specific spectral regions of interest is one of the principal limitation of the presently available spectroscopic databases. Extrapolations to relevant experimental conditions like high temperature is also a major issue for astrophysical applications. Among other molecules, methane is present in the atmosphere of many astrophysical objects. The modeling of its abs…

Experimental study of $^{100}$Tc $\beta$ decay with total absorption $\gamma$-ray spectroscopy

2017

International audience; The β decay of Tc100 has been studied by using the total absorption γ-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ-ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximatio…

Topical anti-inflammatory potential of quercetin in lipid-based nanosystems: In vivo and in vitro evaluation

2013

Purpose: To develop quercetin-loaded phospholipid vesicles, namely liposomes and PEVs (Penetration Enhancer-containing Vesicles), and to investigate their efficacy on TPA-induced skin inflammation. Methods: Vesicles were made from a mixture of phospholipids, quercetin and polyethylene glycol 400 (PEG), specifically added to increase drug solubility and penetration through the skin. Vesicle morphology and self-assembly were probed by Cryo-Transmission Electron Microscopy and Small/Wide Angle X-ray Scattering, as well as the main physico-chemical features by Light Scattering. The anti-inflammatory efficacy of quercetin nanovesicles was assessed in vivo on TPA-treated mice dorsal skin by the d…

Non-linear optical, electrochemical and spectroelectrochemical properties of amphiphilic inner salt porphyrinic systems

2016

Three zwitterionic meso-substituted A3B- and AB2C-porphyrins containing one sulfonato alkylpyridinium substituent and three or two alkoxy-substituted phenyl groups were synthesized in good yield and fully characterized as to their physicochemical properties by a variety of techniques. This new series of inner salt donor-acceptor meso-substituted porphyrin derivatives were prepared for possible application as amphiphilic probes for membrane insertion in the area of combined second-harmonic and two-photon fluorescence cellular microscopy. To this end, the linear and nonlinear optical properties of the compounds were characterized, together with their electrochemical and spectroelectrochemica…