1,721,034 research outputs found
Giant phospholipid vesicles: comparison among the whole lipid sample characteristics using different preparation methods
Full text linkSeveral methods for the preparation of giant unilamellar vesicles (GUVs) using synthetic phosphatidylcholine phospholipids were evaluated. We compared the physical characteristics - in terms of lamellarity and morphology - of the whole lipid sample for each different lipid preparation using the sectioning capability of the two-photon excitation fluorescence microscope. From the evaluation of the entire lipid sample we determined that vesicle size, internal shape and shell thickness distributions depend on the vesicle's preparation method. Our results show that the preparation of giant unilamellar vesicles by the application of external electric fields offers several advantages among the other methods tested here. Using this method a high yield (~95%) of giant unilamellar vesicles with a narrow size distribution was obtained. Independently of the preparation method, some lipid structures, which are held together by lipid tethers, were identified and resolved. These particular lipid structures show shell thickness and size heterogeneity. Labeling the lipid samples with 6-lauroyl-2-(N,N- dimethylamino)naphtalene (LAURDAN) and using the LAURDAN generalized polarization function we show that the lipid packing in these tethers or tubes is similar to those found in the phospholipid vesicles. The fact that both vesicles and tethers are found in the lipid preparations indicates similar stability between these structures.Fil: Bagatolli, Luis Alberto. University of Illinois. Urbana - Champaign; Estados UnidosFil: Parasassi, T.. Consiglio Nazionale delle Ricerche; Italia. Istituto di Medicina Sperimentale; ItaliaFil: Gratton, E.. University of Illinois. Urbana - Champaign; Estados Unido
Human cell membrane oxidative damage induced by single and fractionated doses of ionizing radiation: a fluorescence spectroscopy study.
No full textPublisher: Informa Healthcare
Place of Publication: Englan
Cholesterol protects the phospholipid bilayer from oxidative damage.
No full textPublisher: New York : Pergamon
Copyright © 1995 Elsevier Science Ltd Printed in the USA
Cholesterol modifies water concentration and dynamics in phospholipid bilayers: a fluorescence study using Laurdan probe.
No full textCopyright © 1994 The Biophysical Society Published by Elsevier Inc
Radiation induced membrane oxidative damage in human cells at low and high dose-rate: production and repair.
No full text
Cell membrane lipid molecular dynamics in a solenoid versus a magnetically shielded room.
No full textJournal of the Bioelectromagnetics Society.\ud
Publisher: New York, Copyright 1998 Wiley-Liss, Inc
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
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