Search results for "acetin"
showing 8 items of 18 documents
Faceting and structural anisotropy of nanopatterned CdO(110) layers
2005
CdO(110) layers with a self-organized surface structure have been grown on (10math0) sapphire (m plane) substrates by metal-organic vapor phase epitaxy. The epitaxial relationships between layer and substrate have been determined and a crystallographic model that accounts for the CdO in-plane orientation, which results in a reduced lattice mismatch when the CdO[001] direction is perpendicular to the sapphire c axis, has been proposed. Although the measured lattice parameters indicate that the layers are almost fully relaxed, an anisotropic mosaicity is detected with symmetrical rocking curves attaining minimum values when measured along the CdO[math10] direction. The layer morphology consis…
A NANOPARTICULATE DRUG-DELIVERY SYSTEM FOR RIVASTIGMINE: PHYSICO-CHEMICAL AND IN VITRO BIOLOGICAL CHARACTERIZATION
2007
The preparation and characterization of surface-PE Gylated polymeric nanoparticles are described. These systems were obtained by UV irradiation of PHM and PHM-PEG(2000) as an inverse microemulsion, using an aqueous solution of the PHM/PHM-PEG(2000) copolymer mixture as the internal phase and triacetin saturated with water as the external phase, and characterized by dimensional analysis, zeta-potential measurements and XPS. in vitro biological tests demonstrated their cell compatibility and their ability to escape from phagocytosis. Rivastigmine was encapsulated into the nanoparticle structure and drug-release profiles from loaded samples were investigated in PBS at pH = 7.4 and human plasma.
Interaction of oxygen with Mo(100), Mo(110), and Mo(111) surfaces. RHEED and AES analyses of the molybdenum oxide nucleation and growth
1991
Abstract A study of the nucleation and growth of MoO 3 generated by interaction of oxygen with Mo(100), Mo(110), and Mo(111) single crystalline surfaces is investigated at high oxygen pressure (10 4 Pa) and low temperature (620 to 820 K). The results of RHEED and AES analyses prove that under these oxidation conditions, MoO 3 nucleates directly from the metal without intermediate formation of MoO 2 or nonstoichiometric molybdenum oxide such as Mo 4 O 11 . The structure and orientation of MoO 3 nuclei are characterized in relation with the parent molybdenum surface. On the Mo(110) and Mo(111) surfaces, which are faceting, the nucleation and growth of MoO 3 takes place by successive structura…
Effects of Crystal Field Splitting and Surface Faceting on the Electronic Shell Structure
1992
The shell structure of the valence electrons is clearly observed in all alkali and noble metal clusters containing up to hundreds of atoms[1 – 4]. It is seen in the abundances of the clusters, in the ionization potential and in the polarizability. The shell structure of the valence electrons is closely related to the shell model of nuclei, but is simpler owing to the negligibly small spin-orbit interaction. The ability to produce all sizes of metal clusters has made the metal clusters a test ground for the super-shell structure[5].
Chemical constituents from Anthocleista liebrechtsiana De Wild & T. Durand (Loganiaceae)
2018
Abstract A new steroid derivative, (24S)-3β-hydroxy-7β-methoxyergost-5-ene (1), was isolated along with eleven known compounds: 7α-hydroxysterol (2), β-sitosterol (3), oleanolic acid (4), betulinic acid (5), lupeol (6), swertiaperennin (7), decussatin (8), tetracosanoic acid (9) β-sitosterol-3-O-β- d -glucopyranoside (10), (2R,3S)-2,3-dihydro-2-(3,4-dimethoxyphenyl)-3-hydroxymethyl-5-(2-formylvinyl)-7-hydroxybenzofuran (11) and acacetin 6-C-β- d -glucopyranoside (12) from the tree bark and leaves of Anthocleista liebrechtsiana De Wild & T. Durand. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR) and mass spectrometric data. Compounds 2 and 7–10 have already bee…
Functional investigation and applications of the acetylesterase activity of the Citrus sinensis (L.) Osbeck peel
2020
The hydrolysis of acetyl moieties on a set of commercially relevant substrates was performed by employing the whole tissue of Citrus sinensis (L.) Osbeck peel as an efficient biocatalyst in mild reaction conditions with high degree of regioselectivity. The reaction is done in aqueous media and the product is easily recovered. Optimal reaction conditions were deduced and two practical applications were investigated: the elaboration of acetylglicerols and the preparation of vitamin K1 precursor. Peel waste (flavedo and albedo) from orange juice manufacturing was successfully employed as a biocatalyst.
Grain boundary ridges slow dawn grain boundary motion: In-situ observation
2014
Abstract The impact of grain boundary (GB) ridge on motion of high-angle GB in Zn was studied. The steady-state motion of faceted GB half-loop with [ 10 1 ¯ 0 ] tilt GB and GB ridge was recorded in-situ. The temperatures of faceting–roughening transition were experimentally defined for three GB half-loops. Above the transition temperature GB half-loops had GB “rough-to-rough” ridge with continuously curved GB segments. Below the transition temperature a facet appeared and coexisted with two “facet-to-rough” ridges. For the first time we could extract mobility of “rough-to-rough” and “rough-to-facet” ridges and bring out clearly that GB ridge slows down GB motion. Present removes contradicti…
Breath test using 13C methacetin does not seem to be useful in the assessment of liver function in girls with anorexia nervosa: a case control study
2018
Abstract Background Anorexia nervosa (AN) concerns approximately up to 1.8% of the pediatric female population. One of the complications that can occur in the course of this disease is acute liver failure. This study’s objective was to assess the usefulness of the 13C labeled Methacetin Breath Test (MBT) in the diagnostics of the liver function in girls with eating disorders. Methods For the study 81 girls aged 12 to 17 years were recruited, including 41 patients with confirmed diagnosis of AN (mean age 14.7 ± 1.48 years) and 40 age-matched controls. The diagnosis was based on the present Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. Weight and height were measured…