1,482 research outputs found
Electrochemical oxidation of mitoxantrone at a glassy carbon electrode
Mitoxantrone is an anthracycline used as an antitumour antibiotic for leukaemia and breast cancer treatment, due to its interaction with DNA. However, the molecular mechanism of the antitumour action is not completely understood. Using a glassy carbon electrode the electrochemical oxidation of mitoxantrone was shown to be a complex, pH-dependent, irreversible electrode process involving several metabolites. Comparison of the electrochemical oxidation behaviour of mitoxantrone, ametantrone and aminantrone enabled a deeper understanding of the mechanism and showed the relevance of electrochemical data for the understanding of the cytotoxicity of mitoxantrone. Since mitoxantrone and its oxidation products adsorb strongly on the electrode surface, causing severe problems of electrode fouling, reproducible electroanalytical determinations could only be done at very low concentrations and in an aqueous buffer supporting electrolyte containing 30% ethanol. The detection limit obtained was 10-7 M.http://www.sciencedirect.com/science/article/B6TF4-3W3N6Y2-1J/1/5ffa47da56de732d1903bdf9a6c163c
NUMERICAL MODELING OF THE PLANETARY BOUNDARY LAYER
This work describes the major available techniques to simulate the time and
space evolution of the planetary boundary layer. For homogeneous and
equilibrium conditions the structure of the planetary boundary layer can be
diagnosed from the Monin-Obukhov, Free Convection, Local and Mixed
Layer Similarity theories. For the other atmospheric conditions the
planetary boundary layer can be numerically simulated using first and
second order closure models and large eddy models. The closure models
take into consideration the traditional statistical approach. Large eddy
simulation models are based on the filtered equations of motion and require
the statistical approach to estimate subgrid turbulence
Fucoidan immobilized at the surface of a fibrous mesh presents toxic effects over melanoma cells, but not over non-cancer skin cells
The use of fucoidan, a marine-origin bioactive polymer, is herein proposed as a component of an innovative and effective strategy against melanoma, one of the most aggressive skin cancers. First, fucoidan antitumor activity, in its soluble form, was assessed presenting increased cytotoxicity over melanoma cells when compared to human dermal fibroblasts and keratinocytes. After this antitumor activity validation and trying to develop a more targeted and local strategy aiming to diminish the cytotoxic effects over noncancer cells, fucoidan was immobilized at the surface of an electrospun nanofiber mesh (NFM_Fu), envisioning the development of a therapeutic patch. The maximum immobilization concentration was 1.2 mg mLâ 1, determined by the Toluidine Blue Assay and confirmed by XPS. Furthermore, NFM_Fu is more hydrophilic than NFM, presenting a contact angle of 36°, lower than the 121° of the control condition. NFM_Fu was able to reduce human melanoma cell viability by 50% without affecting human dermal fibroblasts and keratinocytes. Taken together, these results set the basis for a valuable approach for melanoma treatment.This work was developed under the scope of the Structured Projects for R&D&I NORTE-01-0145-FEDER-000021 and NORTE-01-0145-FEDER-000023 supported by the Northern Portugal Regional Operational Programme (NORTE 2020),under the Portugal 2020 Partnership Agreement. The authors would like also to thank NORTE 2020 for financing the Ph.D.scholarship of C.O.“Norte-08-5369-000037”and the Portuguese Foundation for Science and Technology for the Investigator Grant of A.M. (IF/00376/2014). Dr. Luísa Rodrigues is acknowledged by the XPS analysis
A Study of Two-Temperature Non-Equilibrium Ising Models: Critical Behavior and Universality
We study a class of 2D non-equilibrium Ising models based on competing
dynamics induced by contact with heat-baths at two different temperatures. We
make a comparative study of the non-equilibrium versions of Metropolis, heat
bath/Glauber and Swendsen-Wang dynamics and focus on their critical behavior in
order to understand their universality classes. We present strong evidence that
some of these dynamics have the same critical exponents and belong to the same
universality class as the equilibrium 2D Ising model. We show that the bond
version of the Swendsen-Wang update algorithm can be mapped into an equilibrium
model at an effective temperature.Comment: 12 pages of LaTeX plus 18 pages of postscript figures in a uuencoded
file (608k
Exact Solutions of the Klein-Gordon Equation in the Presence of a Dyon, Magnetic Flux and Scalar Potential in the Specetime of Gravitational Defects
In this paper we analyse the relativistic quantum motion of a charged spin-0
particle in the presence of a dyon, Aharonov-Bohm magnetic field and scalar
potential, in the spacetimes produced by an idealized cosmic string and global
monopole. In order to develop this analysis, we assume that the dyon and the
Aharonov-Bohm magnetic field are superposed to both gravitational defects. Two
distinct configurations for the scalar potential, , are considered:
the potential proportional to the inverse of the radial distance, i.e.,
, and the potential proportional to this distance, i.e.,
. For both cases the center of the potentials coincide with the
dyon's position. In the case of the cosmic string the Aharonov-Bohm magnetic
field is considered along the defect, and for the global monopole this magnetic
field pierces the defect. The energy spectra are computed for both cases and
explicitly shown their dependence on the electrostatic and scalar coupling
constants. Also we analyse scattering states of the Klein-Gordon equations, and
show how the phase shifts depend on the geometry of the spacetime and on the
coupling constants parameter.Comment: To be published in CQG. Minor comments adde
Production and characterization of recombinant frutalin expressed in the yeast Pichia Pastoris
CNPq, CAPES, FUNCAP, FCT, ALBAN, UMINHO, UFC, UNIFO
In vitro characterization on the interactions between carboxymethyl-chitosan/poly(amidoamine) dendrimer nanoparticles and neurons/glial cells
[Excerpt] Central nervous system associated disorders are a leading cause of disability worldwide. In recent years targeted drug delivery nanoparticle based systems for intracellular application have been put forward has a possible therapeutic route to follow. In this sense the objective of the present report was to characterize and evaluate the possible applicability of recently developed carboxymethylchitosan/poly(amidoamine) (CMC/PAMAM) dendrimer nanoparticles in central nervous system (CNS) cell populations. Atomic force and transmission electron microscopy observations revealed that these nanoparticles possessed a nanosphere-like shape and sizes between 2–123 nm. [...]info:eu-repo/semantics/publishedVersio
Chitosan/soy-based membranes enhance wound reepithelialization in partial thickness skin wounds
[Excerpt] Chitosan-based biomaterials proved to have promising characteristics for wound dressing and skin regeneration. In the context of developing new natural-based biomaterials for these applications, chitosan and soybean-based biomaterials were proposed. These materials were shown to be non cytotoxic and to impair human leukocytes activation in vitro. Thus the goal of this study was to evaluate the in vivo performance of chitosan/soy-based membranes in the regeneration of partial thickness skin wounds. Excisional skin wounds were created on the backs of rats and the healing capacity of chitosan/soy-based membranes was assessed after 1 and 2 weeks. To promote impaired wound healing all rats were injected with a steroid. [...]This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758) and was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283).info:eu-repo/semantics/publishedVersio
Nonrelativistic Quantum Analysis of the Charged Particle-Dyon System on a Conical Spacetime
In this paper we develop the nonrelativistic quantum analysis of the charged
particle-dyon system in the spacetime produced by an idealized cosmic string.
In order to do that, we assume that the dyon is superposed to the cosmic
string. Considering this peculiar configuration {\it conical} monopole
harmonics are constructed, which are a generalizations of previous monopole
harmonics obtained by Wu and Yang(1976 {\it Nucl. Phys. B} {\bf 107} 365)
defined on a conical three-geometry. Bound and scattering wave functions are
explicitly derived. As to bound states, we present the energy spectrum of the
system, and analyze how the presence of the topological defect modifies
obtained result. We also analyze this system admitting the presence of an extra
isotropic harmonic potential acting on the particle. We show that the presence
of this potential produces significant changes in the energy spectrum of the
system.Comment: Paper accepted for publication in Classical and Quantum Gravit
Position Paper Português Sobre o Uso de Biossimilares na Psoríase
info:eu-repo/semantics/publishedVersio
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