1,721,024 research outputs found
Characterization of cholinesterase activity in three bivalves inhabiting the North Adriatic sea and their possible use as sentinel organisms for biosurveillance programmes
No full textAnticholinesterases constitute a major portion of modern synthetic insecticides and the assessment of cholinesterase
(ChE) inhibition is widely used as a specific biomarker for evaluating the exposure of non-target organisms to these
pollutants.T o evaluate the possible exposure of the North Adriatic sea coastal environment to residues of agriculture
practices, we ascertained whether the oyster, Ostrea edulis and the clam, Tapes philippinarum, highly valuable
resources commercially harvested in the area, could be selected as sentinel species.W e characterized the ChE
biochemical properties in their gills, and for comparison the analysis was carried out also in gills of the mussel,
Mytilus galloprovincialis, extensively used as a biological indicator of water quality.In the oysters and mussels, the
ChE activity was a function of increasing concentrations of substrate in the range 0.01–0.5 mM. Km values were
93"15 and 77"8 mM for O. edulis and M. galloprovincialis, respectively.No detectable ChE activity was found in
gills of T. philippinarum, at any tested condition.Significant inhibition of ChE activity by eserine, carbaryl, and
ethyl-paraoxon was observed in gills of O. edulis and M. galloprovincialis.Although field validation is needed, the
present study suggests that O. edulis may be employed as a biological indicator for assessing pesticide contamination,
whilst T. philippinarum does not seem useful for this purpose.
 2003 Elsevier Science B.V. All rights reserved
Enantioselective Fluorescence Quenching by a Chiral Copper(II) Complex in Ligand Exchange Equilibria
No full textProton NMR and Molecular Modeling Investigations on the Opioid Peptides Dermorphin and Deltorphin II in Aqueous Solution
No full textEffects of ionic liquids on membrane fusion and lipid aggregation of egg-PC liposomes
Full text linkIn this study we have explored the effects of different groups of ionic liquids (ILs) on membrane fusion. The ILs used contain different head groups: N-methylimidazolium, 3-methylpyridinium and N-methylpyrrolidinium; short alkyl or ether functionalized side chains (with one or two ethoxy functionalities), paired with chloride anion. These ILs have been compared with 1-dodecyl-3-methylimidazolium bromide as example of a highly lipophilic IL. The effect of ILs on membrane fusion was investigated through pyrene steady state fluorescence probing, using the IE factor and excimer/monomer ratio (IE/IM) as parameters. The ratio between the vibronic bands of pyrene (I1/I3 ratio) has been used to monitor the effect of ILs on the aggregation properties of egg-PC liposomes. The effect of different ILs’ families was evident; the pyridinium ILs induced a greater extent of fusion than pyrrolidinium and imidazolium ILs having the same side chain. Marginal effect could be attributed to different anions. ILs with short alkyl chains were usually more effective than ether functionalized ones. The aggregation behaviors of ILs having dioxygenated chains have been measured in buffer solution
Effect of CoQ homologues on the fluidity of phospholipid bilayers a studied by fluorescence polarization of perylene
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Chiral Recognition and Separation of Amino Acids by Means of a Copper(II) Complex of Histamine Monofunctionalized b-Cyclodextrin
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