Search results for "absorption."
showing 10 items of 2682 documents
Effect of aqueous extract of Ajuga iva supplementation on plasma lipid profile and tissue antioxidant status in rats fed a high-cholesterol diet
2006
Abstract The present study was designed to explore the possible antioxidant and hypolipidemic effects of the aqueous extract of Ajuga iva (0.5% in the diet) in rats fed a high-cholesterol (1%) diet (HCD). The results indicated that the HCD-Ai versus HCD treatment led to many changes in biochemical parameters. They showed a decrease of plasma total cholesterol (TC) and VLDL-cholesterol but an increase of HDL2-cholesterol. The triacylglycerol contents were reduced in plasma and in VLDL. The lipid peroxidation determined by TBARS was decreased by 75% in plasma. TBARS in liver, heart and kidneys were highly reduced excepted in the adipose tissue. Ajuga iva treatment enhanced superoxide dismutas…
Nanoaggregates Based on New Poly-Hydroxyethyl-Aspartamide Copolymers for Oral Insulin Absorption
2013
The aim of this work was to produce copolymers with an appropriate hydrophilic/hydrophobic balance able to form nanoaggregates with protein molecules and to be used as ideal materials in the field of oral peptide/protein delivery. New anionic polymers obtained by the conjugation of carboxy-bearing ligands, like succinic anhydride and/or cysteine, to hydrophobized α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers have been synthesized and characterized. Starting copolymer was synthesized by the partial derivatization of hydroxyl groups on the PHEA backbone with butylamine (C4) (obtaining the PHEA-C4 copolymer, bearing a butyl moiety). The consecutive reaction of PHEA-C4 with succin…
Demande en restitution. Domaine d'application et marche à suivre
2006
International audience; (Cass. com., 5 juill. 2005, Tiberghien c/ Banque populaire du Nord, pourvoi n° 04-11.320, arrêt n° 1042 FS-P+B, D. 2005.2165, note E. Le Corre-Broly)
Manganese speciation inDiplodon chilensis patagonicusshells: a XANES study
2009
X-ray absorption near-edge spectroscopy (XANES) at the Mn K-edge was used to investigate the environment of Mn in situ within the growth increments of the long-lived freshwater bivalve species Diplodon chilensis patagonicus. Single XANES spectra and Mn Kalpha fluorescence distributions were acquired at submillimetre resolution (up to 100 microm x 50 microm), at Mn concentrations below the weight percent range (100-1000 microg g(-1)) in a high Ca matrix. The position and intensity of the pre-edge feature in the shell spectrum resembles best that of the Mn(II)-bearing reference compounds, suggesting that this is the oxidation state of Mn in the bivalve shells. By comparison with the XANES spe…
Mass transfer and hydrodinamic characteristics of a high aspect ratio self-ingesting reactor for gas-liquid operations
2007
Abstract The mass transfer performance of a gas–liquid self-ingesting stirred reactor is reported both for coalescing and non-coalescing systems. The vessel features are a high aspect ratio and a rather narrow multiple-impeller draft tube, through which the gas phase is ingested and led down to the vessel bottom, where it is finely dispersed into the liquid rising in the annular portion of the vessel. Comparison is made between k L a values determined by several variants of the dynamic method, among which pure oxygen absorption in a previously de-gassed liquid phase. Results show that the gas–liquid mass transfer coefficient values obtained with the last approach are remarkably larger than …
Synergy of Miniemulsion and Solvothermal Conditions for the Low-Temperature Crystallization of Magnetic Nanostructured Transition-Metal Ferrites
2017
Crystalline first-row transition-metal (Mn, Fe, Co, Ni, Cu, and Zn) ferrites were prepared by an unprecedented synergetic combination of miniemulsion synthesis and solvothermal route, pursuing unconventional conditions in terms of space confinement, temperature, and pressure. This synergy allowed for obtaining six different crystalline ferrites at much lower temperature (i.e., 80 °C) than usually required and without any postsynthesis thermal treatment. X-ray diffraction (XRD) revealed that analogous ferrites synthesized by miniemulsion at ambient pressure or in bulk (i.e., from an aqueous bulk solution and not in the confined space of the miniemulsion droplets) either at ambient pressure o…
Sintering process of amorphous SiO2 nanoparticles investigated by AFM, IR and Raman techniques
2011
We report an experimental investigation on the effects of thermal treatments at different temperatures (room-1270 K) and for different duration (0-75 h) on amorphous silica nanoparticles (fumed silica) in powder tablet form. Three types of fumed silica are considered, comprising nearly spherical particles of 40 nm, 14 nm and 7 nm mean diameter. The experimental techniques used here are Raman and infrared absorption (IR) spectroscopy together with atomic force microscopy (AFM). Raman and IR spectra indicate that the structure of nanometer silica particles is significantly different with respect to that of a bulk silica glass. In particular, the main differences regard the positions of the IR…
Effects of heat treatments on the properties of copper phthalocyanine films deposited by glow-discharge-induced sublimation
2006
Copper phthalocyanine films have been deposited by glow-discharge-induced sublimation. The films have undergone postdeposition heat treatments in air at 250 and 290 °C for different times, ranging from 30 min to 14 h. The properties of as-deposited and heated films have been investigated by different techniques in order to determine the effects of heat treatments on the film properties. Fourier transform infrared analysis and UV−visible optical absorption analysis point out a gradual evolution of the film structure from a mixture of α and β polymorphs to the only β polymorph in the sample heated at 290 °C for 14 h. A pronounced decrease of carbon and nitrogen atomic percentages against an o…
Electronic and optical properties of pristine, N- and S-doped water-covered TiO2 nanotube surfaces
2019
For rational design and improvement of electronic and optical properties of water-splitting photocatalysts, the ability to control the band edge positions relative to the water redox potentials and the photoresponse as a function of environmental conditions is essential. We combine ab initio molecular dynamics simulations with ab initio many-body theoretical calculations to predict the bandgap and band edge energies, as well as the absorption spectrum of pristine and N- and S-doped TiO2 nanotubes using the DFT+U and G0W0 approaches. Both levels of theory show similar trends, and N+S-codoping appears to be the optimal system for photocatalytic water splitting both in dry and humid conditions…
Photo-Induced Cluster-to-Cluster Transformation of [Au37–xAgx(PPh3)13Cl10]3+ into [Au25–yAgy(PPh3)10Cl8]+: Fragmentation of a Trimer of 8-Electron Su…
2021
We present the photoinduced size/structure transformation of [Au37-xAgx(PPh3)13Cl10]3+ (M37) into [Au25-yAgy(PPh3)10Cl8]+ (M25) cluster. Single-crystal X-ray diffraction revealed that M37 has a tri-icosahedron M36 metal core assembled via the fusion of three Au7Ag6 icosahedrons in a cyclic fashion and that the M36 core is further protected by phosphine and chloride ligands. The M37 cluster is found to be highly sensitive toward ambient light, and the M37 → M25 transition is observed with 530 nm irradiation, monitored by time-dependent UV-vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and femtosecond transient absorption spectroscopy. Linear-response time-dependent DFT…