2,468 research outputs found
Branched nanostructures and method of synthesizing the same
A branched nanostructure is synthesized. A porous material, with pores having a diameter of approximately 1 .mu.m or less, is placed in a vacuum. It is irradiated with an electron beam. This causes a trunk to grow from the porous material and further causes branches to grow from the trunk
Celastrol: A Spectrum of Treatment Opportunities in Chronic Diseases
This deposit is composed by the main article, and it hasn't any supplementary materials associated.The identification of new bioactive compounds derived from medicinal plants with significant therapeutic properties has attracted considerable interest in recent years. Such is the case of the Tripterygium wilfordii (TW), an herb used in Chinese medicine. Clinical trials performed so far using its root extracts have shown impressive therapeutic properties but also revealed substantial gastrointestinal side effects. The most promising bioactive compound obtained from TW is celastrol. During the last decade, an increasing number of studies were published highlighting the medicinal usefulness of celastrol in diverse clinical areas. Here we systematically review the mechanism of action and the therapeutic properties of celastrol in inflammatory diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel diseases, osteoarthritis and allergy, as well as in cancer, neurodegenerative disorders and other diseases, such as diabetes, obesity, atherosclerosis, and hearing loss. We will also focus in the toxicological profile and limitations of celastrol formulation, namely, solubility, bioavailability, and dosage issues that still limit its further clinical application and usefulness.Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/92860/2013, PTDC/BIM-MEC/4665/2014); European Research Council grants: (ERC-2014-CoG 647888-iPROTECTION).info:eu-repo/semantics/publishedVersio
Cómo debería enfrentar la industria del petróleo en Colombia el riesgo de la pérdida de autosuficiencia y la condición de país exportador de petróleo y gas
Nuestro país tiene en la actualidad una urgente necesidad de encontrar nuevas reservas de hidrocarburos, teniendo en cuenta que en los últimos años, a pesar de haberse incrementado en forma significativa los niveles de producción, no se cuentan con nuevos descubrimientos que impacten favorablemente el escenario de autosuficiencia energética de petróleo y gas.
Dentro de las opciones que en principio podrían considerarse de alto impacto, se tienen la exploración y explotación de crudos pesados y extra-pesados, los denominados Yacimientos No Convencionales, los yacimientos de gas costa afuera, al igual que los proyectos de recobro mejorado aplicado a campos maduros ya descubiertos y, finalmente, la exploración intensiva en áreas de bajo riesgo.Introducción. Formulación del problema. Justificación. Hipótesis. Objetivos.
Objetivo general. Objetivos específicos. Estado del Arte. Marco teórico. Evolución de las teorías de explotación de recursos naturales. La Enfermedad Holandesa y la maldición de los recursos naturales. Los recursos naturales y la teoría económica.Importancia de la Industria Petrolera en la Economía del País. Técnicas Mejoradas de Recobro aplicadas a Campos Maduros. Yacimientos Costa Afuera. Incremento de la actividad exploratoria en áreas con bajo riesgo. Los Crudos Pesados y Extra-Pesados. Los Yacimientos No Convencionales. Metodología. Escenarios de Simulación. Exploración en Cuencas Maduras de bajo riesgo. Crudos pesados y extra pesados. Producción Incremental en un campo Maduro. Los Yacimientos No Convencionales.Yacimientos de Gas Costa Afuera. Jerarquización Multivariable & “Value. Management” .Proyecciones de Oferta y Demanda de petróleo y gas en Colombia. Análisis de la Estrategia Propuesta. Conclusiones
Recomendaciones.Magíster en Administración de EmpresasMaestrí
Elimination of the numerical Cerenkov instability for spectral EM-PIC codes
When using an electromagnetic particle-in-cell (EM-PIC) code to simulate a
relativistically drifting plasma, a violent numerical instability known as the
numerical Cerenkov instability (NCI) occurs. The NCI is due to the unphysical
coupling of electromagnetic waves on a grid to wave-particle resonances,
including aliased resonances, i.e., , where and refer to the time and space
aliases and the plasma is drifting relativistically at velocity in the
-direction. Recent studies have shown that an EM-PIC code which uses a
spectral field solver and a low pass filter can eliminate the fastest growing
modes of the NCI. Based on these studies a new spectral PIC code for studying
laser wakefield acceleration (LWFA) in the Lorentz boosted frame was developed.
However, we show that for parameters of relevance for LWFA simulations in the
boosted frame, a relativistically drifting plasma is susceptible to a host of
additional unstable modes with lower growth rates, and that these modes appear
when the fastest growing unstable modes are filtered out. We show that these
modes are most easily identified as the coupling between modes which are purely
transverse (EM) and purely longitudinal (Langmuir) in the rest frame of the
plasma for specific time and space aliases. We rewrite the dispersion relation
of the drifting plasma for a general field solver and obtain analytic
expressions for the location and growth rate for each unstable mode, i.e, for
each time and space aliased resonances. We show for the spectral solver that
when the fastest growing mode is eliminated a new mode at the fundamental
resonance () can be seen. (Please check the whole abstract in the
paper).Comment: 36 pages, 12 figure
Fully kinetic large scale simulations of the collisionless Magnetorotational instability
We present two-dimensional particle-in-cell (PIC) simulations of the fully
kinetic collisionless magnetorotational instability (MRI) in weakly magnetized
(high ) pair plasma. The central result of this numerical analysis is
the emergence of a self-induced turbulent regime in the saturation state of the
collisionless MRI, which can only be captured for large enough simulation
domains. One of the underlying mechanisms for the development of this turbulent
state is the drift-kink instability (DKI) of the current sheets resulting from
the nonlinear evolution of the channel modes. The onset of the DKI can only be
observed for simulation domain sizes exceeding several linear MRI wavelengths.
The DKI, together with ensuing magnetic reconnection, activate the turbulent
motion of the plasma in the late stage of the nonlinear evolution of the MRI.
At steady state, the magnetic energy has an MHD-like spectrum with a slope of
for ). We also
examine the role of the collisionless MRI and associated magnetic reconnection
in the development of pressure anisotropy. We study the stability of the system
due to this pressure anisotropy, observing the development of mirror
instability during the early-stage of the MRI. We further discuss the
importance of magnetic reconnection for particle acceleration during the
turbulence regime. In particular, consistent with reconnection studies, we show
that at late times the kinetic energy presents a characteristic slope of
in the high-energy region.Comment: 13 pages, 9 figures, accepted to Astrophysical Journa
Drugs that simultaneously down-regulate IL-1β and TNF secretion significantly reduce inflammation in a rat model of antigen-induced arthritis
Celastrol: A Spectrum of Treatment Opportunities in Chronic Diseases
The identification of new bioactive compounds derived from medicinal plants with significant therapeutic properties has attracted considerable interest in recent years. Such is the case of the Tripterygium wilfordii (TW), an herb used in Chinese medicine. Clinical trials performed so far using its root extracts have shown impressive therapeutic properties but also revealed substantial gastrointestinal side effects. The most promising bioactive compound obtained from TW is celastrol. During the last decade, an increasing number of studies were published highlighting the medicinal usefulness of celastrol in diverse clinical areas. Here we systematically review the mechanism of action and the therapeutic properties of celastrol in inflammatory diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel diseases, osteoarthritis and allergy, as well as in cancer, neurodegenerative disorders and other diseases, such as diabetes, obesity, atherosclerosis, and hearing loss. We will also focus in the toxicological profile and limitations of celastrol formulation, namely, solubility, bioavailability, and dosage issues that still limit its further clinical application and usefulness
A ECONOMIA POLÍTICA DA DESVALORIZAÇÃOCAMBIAL: OS EFEITOS ASSIMÉTRICOS DO DESALINHAMENTO CAMBIAL NO CONFLITOINTER-CLASSES
IL-9 expression by invariant NKT cells is not imprinted during thymic development
Copyright © 2015 by The American Association of Immunologists, Inc. All rights reservedInvariant NKT (iNKT) cell thymic development can lead to distinct committed effector lineages, namely NKT1, NKT2, and NKT17. However, following identification of IL-9-producing iNKT cells involved in mucosal inflammation, their development remains unaddressed. In this study, we report that although thymic iNKT cells from naive mice do not express IL-9, iNKT cell activation in the presence of TGF-β and IL-4 induces IL-9 secretion in murine and human iNKT cells. Acquisition of IL-9 production was observed in different iNKT subsets defined by CD4, NK1.1, and neuropilin-1, indicating that distinct functional subpopulations are receptive to IL-9 polarization. Transcription factor expression kinetics suggest that regulatory mechanisms of IL-9 expression are shared by iNKT and CD4 T cells, with Irf4 and Batf deficiency deeply affecting IL-9 production. Importantly, adoptive transfer of an enriched IL-9(+) iNKT cell population leads to exacerbated allergic inflammation in the airways upon intranasal immunization with house dust mite, confirming the ability of IL-9-producing iNKT cells to mediate proinflammatory effects in vivo, as previously reported. Taken together, our data show that peripheral iNKT cells retain the capacity of shaping their function in response to environmental cues, namely TGF-β and IL-4, adopting an IL-9-producing NKT cell phenotype able to mediate proinflammatory effects in vivo, namely granulocyte and mast cell recruitment to the lungs.This work was supported by Fundação Para a Ciência e Tecnologia, Portugal Grants PTDC/SAU-TOX/114424/2009 and HMSP-ICT/0034/2013 and the Novo Nordisk/European Foundation for the Study of Diabetes (to L.G.), as well as by grants from the Fundação Para a Ciência e Tecnologia, Portugal, the European Molecular Biology Organization, the European Research Council, and the U.S. National Blood Foundation (to H.V.-F.). A.A.-D., C.F.A., D.F.-P., and M.M. were supported by fellowships from the Fundação Para a Ciência e Tecnologia, Portugal.info:eu-repo/semantics/publishedVersio
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