26 research outputs found
Biological decolorization of xanthene dyes by anaerobic granular biomass
Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes—Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L−1, while the process rates were independent of the biomass concentration above 1.89 g VSS L−1. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L−1 AC0). Using different modified AC samples (from the treatment of AC0), a threefold higher rate was obtained with the most basic one, \textAC\textH2ACH2, as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na2S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.This work was supported by the PTDC/AMB/69335/2006 project grants (Fundacao para a Ciencia e Technologia, FCT, Portugal), BRAIN project (ID 6681, European Social Found and Romanian Government and the grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-ID-PCE-2011-3-0559, Contract 265/2011
Morphological and Chemical Mechanisms of Elongated Mineral Particle Toxicities
Much of our understanding regarding the mechanisms for induction of disease following inhalation of respirable elongated mineral particles (REMP) is based on studies involving the biological effects of asbestos fibers. The factors governing the disease potential of an exposure include duration and frequency of exposures; tissue-specific dose over time; impacts on dose persistence from in vivo REMP dissolution, comminution, and clearance; individual susceptibility; and the mineral type and surface characteristics. The mechanisms associated with asbestos particle toxicity involve two facets for each particle's contribution: (1) the physical features of the inhaled REMP, which include width, length, aspect ratio, and effective surface area available for cell contact; and (2) the surface chemical composition and reactivity of the individual fiber/elongated particle. Studies in cell-free systems and with cultured cells suggest an important way in which REMP from asbestos damage cellular molecules or influence cellular processes. This may involve an unfortunate combination of the ability of REMP to chemically generate potentially damaging reactive oxygen species, through surface iron, and the interaction of the unique surfaces with cell membranes to trigger membrane receptor activation. Together these events appear to lead to a cascade of cellular events, including the production of damaging reactive nitrogen species, which may contribute to the disease process. Thus, there is a need to be more cognizant of the potential impact that the total surface area of REMP contributes to the generation of events resulting in pathological changes in biological systems. The information presented has applicability to inhaled dusts, in general, and specifically to respirable elongated mineral particles
Insanity, belonging and citizenship: mentally ill people who went to and/or returned from Europe in the Late Ottoman Era
A New Method of Oral Drug Provocation Testing for Determining Safe Alternatives for Patients with Non-Steroidal Anti-Inflammatory Drug Intolerance: The Triple Test
From education to job opportunities. Defining professional profiles for geographers with high competences in GIS environment
In this paper, the importance is underlined of promoting higher education
and training courses and opportunities, focused on a close connection between GIS
and geography to cover topics of remarkable and daily social interest. In the first
part of the contribution, some educational key points are defined in order to fuel a
virtuous circle which can provide considerable methodological and applied skills in
the use of GIS applications. It is considered fundamental to broaden one’s mind, to
provide practice to the theories, to give enthusiasm and security in one’s own skills,
to create a community of Geographers able to provide important added value in
different research fields and workplaces. Therefore, it seems essential to build a trait
d’union between the university and theworkplace. Particular attention is attributed to
well-structured university modules founded on GIS applications, to intensive courses
for postgraduates and to the geocartographic laboratories. In the second part of the
paper, the focus will be on some examples of professional profiles forGeographers in
order to define specific professional categories. In particular, ten application fields for
Geographers with high competences and abilities in GIS environment are identified
and explained with relative examples. In all these cases, a rigorous approach founded
on geographical contents and a wide, updated and concrete use of GIS functionalities
and extensions is required