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1.
Materials (Basel) ; 13(8)2020 Apr 21.
Article in English | MEDLINE | ID: mdl-32326154

ABSTRACT

As organic dyes are a major source of pollution, it is important to develop novel and efficient heterogeneous catalysts with high activity for their degradation. In this work, two innovative techniques, atomic layer deposition and electrospinning, were used to prepare palladium nanoparticles (Pd NPs) supported on carbon nanofibers (CNFs). The sample morphology was investigated using scanning and transmission electron microscopy. This showed the presence of nanofibers of several micrometers in length and with a mean diameter of 200 nm. Moreover, the size of the highly dispersed Pd NPs was about 7 nm. X-ray photoelectron spectroscopy visually validated the inclusion of metallic Pd. The prepared nano-catalysts were then used to reduce methyl orange (MO) in the presence of sodium borohydride (NaBH4). The Freundlich isotherm model was the most suitable model to explain the adsorption equilibrium for MO onto the Pd/CNF catalysts. Using 5 mL MO dye-solution (0.0305 mM) and 1 mL NaBH4 (0.026 mM), a 98.9% of catalytic activity was achieved in 240 min by 0.01 g of the prepared nano-catalysts Pd/C (0.016 M). Finally, no loss of catalytic activity was observed when such catalysts were used again. These results represent a promising avenue for the degradation of organic pollutants and for heterogeneous catalysis.

2.
Mult Scler Relat Disord ; 40: 101935, 2020 May.
Article in English | MEDLINE | ID: mdl-31951861

ABSTRACT

'No evidence of disease activity' (NEDA) that has been identified as a potential outcome measure for the evaluation of DMTs effects. The concept has been adopted from other diseases such as cancer where treatment is intended to free the patient from the disease. Disease-free status has been substituted by NEDA in MS, since we are limited when it comes to fully evaluating the underlying disease. In general, NEDA, otherwise termed as NEDA-3, is defined by the lack of disease activity based on the absence of clinical relapses, disability progression with the expanded disability status score (EDSS), and radiological activity. Recently, brain atrophy, a highly predictive marker of disability progression, has been added as a fourth component (NEDA-4). The use of this composite allowed a more comprehensive assessment of the disease activity. Indeed, it has an important role in clinical trials as a secondary outcome in addition to primary endpoints. However, the evidence is insufficient regarding the ability of NEDA to predict future disability and treatment response. Moreover, combining different composites does not eliminate the limitation of each, therefore the use of NEDA in clinical routine is still not implemented. The aim of this review is first to report from the literature the available definitions of NEDA and its different variants, and second, evaluate the importance of its use as a surrogate marker to assess the efficacy of different DMTs.


Subject(s)
Disease Progression , Immunologic Factors/pharmacology , Magnetic Resonance Imaging , Multiple Sclerosis , Outcome Assessment, Health Care , Severity of Illness Index , Humans , Multiple Sclerosis/diagnostic imaging , Multiple Sclerosis/drug therapy , Multiple Sclerosis/pathology , Multiple Sclerosis/physiopathology
3.
ChemSusChem ; 11(18): 3023-3047, 2018 Sep 21.
Article in English | MEDLINE | ID: mdl-29984904

ABSTRACT

Environmental and energy problems have drawn much attention owing to rapid population growth and accelerated economic development. For instance, photocatalysis, "a green technology", plays an important role in solar-energy conversion owing to its potential to solve energy and environmental problems. Recently, many efforts have been devoted to improving visible-light photocatalytic activity by using titanium dioxide as a photocatalyst as a result of its wide range of applications in the energy and environment fields. However, fast charge recombination and an absorption edge in the UV range limit the photocatalytic efficiency of TiO2 under visible-light irradiation. Many investigations have been undertaken to overcome the limitations of TiO2 and, therefore, to enhance its photocatalytic activity under visible light. The present literature review focuses on different strategies used to promote the separation efficiency of electron-hole pairs and to shift the absorption edge of TiO2 to the visible region. Current synthesis techniques used to elaborate several nanostructures of TiO2 -based materials, recent progress in enhancing visible photocatalytic activity, and different photocatalysis applications will be discussed. On the basis of the studies reported in the literature, we believe that this review will help in the development of new strategies to improve the visible-light photocatalytic performance of TiO2 -based materials further.

4.
Nanotechnology ; 21(12): 125701, 2010 Mar 26.
Article in English | MEDLINE | ID: mdl-20182009

ABSTRACT

Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe(2)O(3)) nanotubes and polycrystalline Fe(3)C nanofibers were obtained by simple air or mixed gas (H(2), Ar) annealing treatments. Using the air annealing treatment, a high control of the morphology as well as of the wall thickness of the nanotubes was demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H(2) and Ar) were used for the annealing treatments, for the first time polycrystalline Fe(3)C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe(3)C nanoparticle stability and nanofiber cohesion. The morphology and structural properties of all these iron-based 1D nanostructures were fully characterized by SEM, TEM, XRD and Raman spectroscopy.

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