Search results for "RACE"
showing 10 items of 4458 documents
Flow cytometric analysis of chronic and acute toxicity of copper(II) on the marine dinoflagellateAmphidinium carterae
2001
Background Copper(II) is a heavy metal whose levels have increased in some marine ecosystems to polluting levels. Dinoflagellates, an important phytoplankton group, are at the base of aquatic food chains and bioaccumulation of copper by these microorganisms can result in complex ecosystem alterations, so we investigated how copper disturbs those cells. Methods Cytotoxic effects of sublethal and lethal copper concentrations ranging from 4.2 nM (control condition) to 3.13 μM estimated labile copper were studied in batch cultures of Amphidinium carterae. Cell morphology, motility, autofluorescence, and fluorescein diacetate (FDA)–dependent fluorescence generation were evaluated by flow cytomet…
LE VESCICOLE EXTRACELLULARI VEGETALI PER LO SVILUPPO DI NUOVI NUTRACEUTICI: STUDIO PRE-CLINICO E CLINICO DELLE PROPRIETÀ BIOLOGICHE DELLE VESCICOLE I…
2021
Razionale dello studio: Le vescicole extracellulari (EVs) sono strutture lipoproteiche rilasciate dalle cellule animali e vegetali, che veicolano sostanze bioattive tra cui lipidi, proteine, acidi nucleici e altri metaboliti, rendendole più stabili e biodisponibili. EVs isolate da semi, foglie e frutti di svariate specie vegetali presentano attività anti-tumorale, anti-infiammatoria ed anti-ossidante. Metodi e Risultati: Il nostro gruppo di ricerca si occupa da anni della caratterizzazione strutturale e funzionale delle EVs da succo di limone (LEVs). Le LEVs esercitano effetti antinfiammatori sia in vitro, su linee di macrofagi murini, che ex vivo, su linfociti T, attraverso l’inibizione de…
Nuclear localization but not PML protein is required for incorporation of the papillomavirus minor capsid protein L2 into virus-like particles.
2004
ABSTRACT Recent reports suggest that nuclear domain(s) 10 (ND10) is the site of papillomavirus morphogenesis. The viral genome replicates in or close to ND10. In addition, the minor capsid protein, L2, accumulates in these subnuclear structures and recruits the major capsid protein, L1. We have now used cell lines deficient for promyelocytic leukemia (PML) protein, the main structural component of ND10, to study the role of this nuclear protein for L2 incorporation into virus-like particles (VLPs). L2 expressed in PML protein knockout (PML −/− ) cells accumulated in nuclear dots, which resemble L2 aggregates forming at ND10 in PML protein-containing cells. These L2 assemblies also attracted…
The Extracellular δ-Domain is Essential for the Formation of CD81 Tetraspanin Webs
2014
AbstractCD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes. Surprisingly, we find that large CD81 platforms assemble via the short extracellular δ-domain, independent from a strong primary partner binding and from weak interactions mediated by palmitoylation. The δ-domain is also essential for the platforms to function during viral entry. We propose that, ins…
In vitro studies on the activation of the hepatitis C virus NS3 proteinase by the NS4A cofactor.
1996
AbstractProteolytic processing of the nonstructural proteins of the hepatitis C virus (HCV) is mediated by two viral proteinases: the NS2-3 proteinase cleaving at the NS2/3 junction and the NS3 serine-type proteinase responsible for processing at the NS3/4A, NS4A/B, NS4B/5A, and NS5A/B sites. Activity of the NS3 proteinase is modulated by NS4A. In the absence of this cofactor processing at the NS3-dependent sites does not occur or, in the case of the NS5A/B junction, is poor but increased when NS4A is present. Although recent studies demonstrated that proteinase activation requires direct interaction between NS3 and NS4A, the mechanism by which NS4A exerts the activation function is not kno…
Passive Control of Linear Structures Equipped with non-Linear Viscous Dampers and Amplification Mechanism
2008
Fluid damper devices in civil structures such as buildings or bridges are commonly used as energy absorbers for seismic protection. The problem in the response analysis of structures with filled dampers mainly consists in the fact that, due to the strongly nonlinear behavior of such equipments, the response spectrum technique fails. Moreover, in order to enhance the damping effect various toggle brace configurations have been recently proposed. In this paper by using the concept of power spectral density function compatible with the elastic response spectrum and the stochastic linearization technique, the equivalent damping ratio is obtained. It is shown that once the system is linearized r…
La visualisation au service de l'analyse d'interactions Implémentation d'une forme de visualisation générique au sein d'un environnement d'analyse de…
2009
International audience; La visualisation de traces d'interactions est une composante importante de leur analyse dans le cadre de l'évaluation d'usages d'EIAH collaboratifs. Différentes présentations permettent en effet aux chercheurs de plus facilement explorer des corpus parfois très complexes. Dans cet article, nous examinons les besoins de chercheurs désirant visualiser et analyser des traces d'interaction et introduisons la notion de partition d'interaction, une forme générique de visualisation adaptée à ces besoins. Nous montrons de quelle manière cette fonction a été implémentée au sein de Tatiana, un environnement d'analyse de traces. En particulier, nous illustrons comment l'archite…
The impact of Mt. Etna volcanic emissions on the atmospheric deposition: developments and improvements during three decades of studies
2022
Volcanic emissions are an important source of gases and particles to the atmosphere. Mount Etna discharges a permanent volcanic plume consisting of water vapor and gaseous species (CO2, SO2, HCl and HF, mainly), metals, acid droplets, and solid particles. This plume interacts with meteoric water during precipitations events, so the chemical signature of the plume is impressed on the rainwater. Over the past 32 years, the impact of Etna's emissions on atmospheric deposition has been investigated in many research projects by our team. Sampling methodologies and analytical procedures have been improved over the years. The first study of the concentration of water-soluble inorganic ions in week…
Chemistry and fluxes of major and trace element from worldwide passive degassing volcanoes: a critical review
2015
Volcanic emissions represent one of the most important natural sources of trace elements (e.g. As, Cd, Cu, Hg, Pb, Sb, Tl and Zn) into the atmosphere, sequentially influencing the hydrosphere, lithosphere and biosphere. The human health hazard during episodic volcanic eruptions generally follows from deposition of coarse and fine particles (2.5-10 and < 2.5 μm) that produces effects such as asthma and lung and respiratory disease. Regarding passive degassing volcanoes, the harmful effects of fluorine fumigation are known both for vegetation (foliar necrosis) and human/animals (fluorosis), but only a few studies have been focused on the effects of potentially toxic trace elements. From a …
Are the Salinelle mud volcanoes threatening human health or are anthropogenic activities threatening the Salinelle mud volcanoes?
2012
Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000 μg m−3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000 μg m−…