Search results for "ASTER"
showing 10 items of 2223 documents
Strategies for the enantiomeric determination of amphetamine and related compounds by liquid chromatography.
2002
This paper summarizes recent research on the stereospecific analysis of amphetamine, its analogs and metabolites, by liquid chromatography. The different methods proposed have been evaluated and compared in terms of resolution power, time of analysis, sensitivity, or potential for automation. Chiral derivatization, followed by separation of the diastereomers formed in achiral chromatographic systems, is still the method preferred for the analysis of amphetamines at trace levels, as derivatization also improves analyte detectability. This is the method of choice for the enantiomeric analysis of amphetamines at the low concentrations typically encountered in biological samples. In recent year…
Ancestral Reconstruction and Investigations of Genomic Recombination on some Pentapetalae Chloroplasts
2019
Abstract In this article, we propose a semi-automated method to rebuild genome ancestors of chloroplasts by taking into account gene duplication. Two methods have been used in order to achieve this work: a naked eye investigation using homemade scripts, whose results are considered as a basis of knowledge, and a dynamic programming based approach similar to Needleman-Wunsch. The latter fundamentally uses the Gestalt pattern matching method of sequence matcher to evaluate the occurrences probability of each gene in the last common ancestor of two given genomes. The two approaches have been applied on chloroplastic genomes from Apiales, Asterales, and Fabids orders, the latter belonging to Pe…
The transmembrane receptor Uncoordinated5 (Unc5) is essential for heart lumen formation in Drosophila melanogaster
2011
AbstractTransport of liquids or gases in biological tubes is fundamental for many physiological processes. Our knowledge on how tubular organs are formed during organogenesis and tissue remodeling has increased dramatically during the last decade. Studies on different animal systems have helped to unravel some of the molecular mechanisms underlying tubulogenesis. Tube architecture varies dramatically in different organs and different species, ranging from tubes formed by several cells constituting the cross section, tubes formed by single cells wrapping an internal luminal space or tubes that are formed within a cell. Some tubes display branching whereas others remain linear without interse…
Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties.
2018
Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) w…
Contribution of sponge genes to unravel the genome of the hypothetical ancestor of Metazoa (Urmetazoa)
2001
Recently the term Urmetazoa, as the hypothetical metazoan ancestor, was introduced to highlight the finding that all metazoan phyla including the Porifera (sponges) are derived from one common ancestor. Sponges as the evolutionarily oldest, still extant phylum, are provided with a complex network of structural and functional molecules. Analyses of sponge genomes from Demospongiae (Suberites domuncula and Geodia cydonium), Calcarea (Sycon raphanus) and Hexactinellida (Aphrocallistes vastus) have contributed also to the reconstruction of the evolutionary position of Metazoa with respect to Fungi. Furthermore, these analyses have provided evidence that the characteristic evolutionary novelties…
Synthesis and conformational analysis of tetrahydroisoquinoline- and piperidine-fused 1,3,4,2-oxadiazaphosphinanes, new ring systems
2006
Abstract Through cyclization of tetrahydroisoquinoline and piperidine 1,2-hydrazino alcohols with phenylphosphonic dichloride and phenyl dichlorophosphate, P-epimeric diastereomers of 1,6,7,11b-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[5,4-a]isoquinoline-3-oxides ( 13 and 14 ), 1,6,11,11a-tetrahydro-4H-1,3,4,2-oxadiazaphosphino[4,5-b]isoquinoline-3-oxides ( 15 and 16 ) and 1,6,7,8,9,9a-hexahydro-4H-pyrido[1,2-d][1,3,4,2]oxadiazaphosphinane-3-oxides ( 17 and 18 ), the first representatives of these ring systems, were prepared. NMR and X-ray diffraction studies revealed that, independently of the P-substituent and the relative configuration of the phosphorus atom, 13 , 14 , 17 and 18 could be c…
IL CANTIERE DEL COMPLESSO CARMELITANO DELL’ANNUNZIATA A TRAPANI NELLA SECONDA METÀ DEL CINQUECENTO
2016
Il complesso carmelitano dell’Annunziata a Trapani, costituito dalla chiesa e dal convento annesso (oggi sede del Museo Regionale Agostino Pepoli), appare come un’architettura fortemente stratificata, frutto di una lunga e complessa vicenda progettuale che si snoda dal XIV secolo fino alla metà del Settecento. Il presente studio intende contribuire alla conoscenza del cantiere dell’Annunziata nella seconda metà del Cinquecento, un periodo ancora poco indagato dalle ricerche finora condotte sulla fabbrica, offrendo in particolare alcune riflessioni sui maestri impegnati nella costruzione del complesso architettonico, a partire dall’esame della documentazione relativa alla gestione amministra…
Recent and new taxonomic acquisitions in some native genera of Asteraceae from southern Italy and Sicily
2021
After a brief review of the recent acquisition in some native genera of family Asteraceae from southern Italy and Sicily, a new endemic species of Anthemis (sect. Hiorthia) is described from Sicily and named Anthemis parlatoreana. The locus classicus of the new taxon, falling in the NW Tyrrhenian coast of the island (Castellammare del Golfo, Trapani), coincides with that of Ptilostemon greuteri, another endemic very rare species of the Sicilian flora. Data on the morphology, distribution, ecology and conservation status of the new species are provided. The taxonomic relationships with the other Sicilian taxa of the same section, in particular A. cupaniana, are also analyzed. The simultaneou…
Chemical composition of essential oils of Anthemis secundiramea Biv. subsp. secundiramea (Asteraceae) collected wild in Sicily and their activity on …
2016
In the present study, the chemical composition of the essential oil from the aerial parts of Anthemis secundiramea Biv. subsp. secundiramea L. collected in Sicily was evaluated by GC and gas chromatography–mass spectrometry. The main components of A. secundiramea were (Z)-lyratyl acetate (14.6%), (Z)-chrysanthenyl acetate (9.9%), (Z)-chrysanthenol (8.7%) and (E)-chrysanthenyl acetate (7.7%). The comparing with other studied oils of genus Anthemis belonging to the same clade is discussed. Antibacterial and antifungal activities against some micro-organisms infesting historical art craft, were also determined.
Metabolite profile and in vitro activities of Phagnalon saxatile (L.) Cass. relevant to treatment of Alzheimer’s disease
2009
The present study describes for the first time the in vitro properties (inhibition of NO production and anticholinesterase) of Phagnalon saxatile (L.) Cass. (Asteraceae). The methanolic extract showed antioxidant activity that was measured by DPPH assay and beta-carotene bleaching test. The same extract inhibited NO production in the murine monocytic macrophage cell line RAW 264.7. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of Ellman's method. Purification of the MeOH extract of P. saxatile allowed the isolation of phenolic compounds. Among them, the compounds that most effectively inhibited lipopolysaccharide-induced NO production …