3,057 research outputs found
Genetic and Molecular Factors in Drug-Induced Liver Injury: A Review
The diagnosis of drug-induced liver injury (DILI) is challenging and based on complex diagnostic criteria. DILI falls into two main categories i) intrinsic 'dose-dependent' Type A reactions ii) 'idiosyncratic' or Type B reactions (which are usually not predictable). Idiosyncratic reactions can be immunoallergic (hypersensitivity), or metabolic, although overlap between categories can occur. The aim of this review is to summarise the general view of underlying mechanisms in DILI and to highlight individual risk factors for developing hepatotoxicity. Polymorphisms of bioactivation/ toxification pathways through CYP450 enzymes (Phase I), detoxification reactions (Phase II) and excretion/transport (Phase III) are explored together with immunological factors that might determine DILI. The importance of establishing a multidisciplinary and multi-centric network to promote the understanding and research in hepatotoxicity is underlined. Challenges such as genetic analyses for association studies and whole genome studies, pharmacogenetic testing and future approaches to study DILI are considered. Knowledge regarding these operational mechanisms could provide further insight for the prospective identification of susceptible patients at risk of developing drug-induced hepatotoxicity.
Tunable diffusion of magnetic particles in a quasi-one-dimensional channel
The diffusion of a system of ferromagnetic dipoles confined in a
quasi-one-dimensional parabolic trap is studied using Brownian dynamics
simulations. We show that the dynamics of the system is tunable by an in-plane
external homogeneous magnetic field. For a strong applied magnetic field, we
find that the mobility of the system, the exponent of diffusion and the
crossover time among different diffusion regimes can be tuned by the
orientation of the magnetic field. For weak magnetic fields, the exponent of
diffusion in the subdiffusive regime is independent of the orientation of the
external field.Comment: 9 pages, 13 figures, to appear in Phys. Rev. E (2013
Molecular modeling of -endotoxins from Bacillus thuringiensis.
Bacillus thuringiensis (Bt) is a Gram-positive entomotoxic bacterium widely used to control crop pests and disease vectors. Since the introduction of transgenic plants expressing Bt genes, it has been demonstrated that Bt-crops constitute an important tool in the increase of productivity and in the decrease of the use of chemical pesticides. Its success comes from the production of the ?-endotoxins (Cry). These toxins share a molecular mechanism of similar action or, at least, some common aspects
Observations of OJ 287 from the Geodetic VLBI Archive of the Washington Correlator
We present 27 geodetic VLBI maps of OJ 287 obtained from the archive of the
Washington correlator. The observations presented here were made between 1990
October and 1996 December. During this period a sequence of six superluminal
components has been identified. We measured the proper motion of these
components to be approximately 0.5 mas/yr, which is about twice as high as that
seen in previous VLBI observations. These results imply a higher component
ejection rate than previously observed, in good agreement with the observed
occurrences of radio outbursts. We have examined a possible connection between
VLBI components and optical flares in the framework of a binary black hole
system.Comment: 9 pages, 5 included figures, emulateapj.sty, accepted to The
Astrophysical Journa
Experiences in teaching Hydrogen Technologies in the framework of the International Campus of Excellence Andalucia TECH
The increasing importance of hydrogen technologies is demanding prepared professionals in the numerous topics related to this energy vector. Apart from some basic and advanced courses given by actual experts in these topics, universities must play an important role in the general formation of future professionals. In this way, the International Campus of Excellence (ICE) AndalucĂa TECH has created several degrees taught jointly by its participating universities of Seville (US) and MĂĄlaga (UMA). Among those degrees, Energy Engineering is the best suited to the field of this conference because this degree provide future engineers with specialized training in energy generation, transformation and management. In relation to hydrogen technologies this degree includes a cross sectional optional unit named Hydrogen Based Systems (4.5 ECTS/112.5 h), which is placed in the last term of the fourth year and sharing space with work placement and mobility courses.
This paper will present some authorâs experiences as teachers of that unit during its short history of only three years. In spite of being a joint degree, which is coordinated between both universities (US and UMA) trying to give similar contents, it is interesting to highlight the differential experiences coming from the teachers of both universities in relation to the teaching methodologies and academic results.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Invasion Percolation Between two Sites
We investigate the process of invasion percolation between two sites
(injection and extraction sites) separated by a distance r in two-dimensional
lattices of size L. Our results for the non-trapping invasion percolation model
indicate that the statistics of the mass of invaded clusters is significantly
dependent on the local occupation probability (pressure) Pe at the extraction
site. For Pe=0, we show that the mass distribution of invaded clusters P(M)
follows a power-law P(M) ~ M^{-\alpha} for intermediate values of the mass M,
with an exponent \alpha=1.39. When the local pressure is set to Pe=Pc, where Pc
corresponds to the site percolation threshold of the lattice topology, the
distribution P(M) still displays a scaling region, but with an exponent
\alpha=1.02. This last behavior is consistent with previous results for the
cluster statistics in standard percolation. In spite of these discrepancies,
the results of our simulations indicate that the fractal dimension of the
invaded cluster does not depends significantly on the local pressure Pe and it
is consistent with the fractal dimension values reported for standard invasion
percolation. Finally, we perform extensive numerical simulations to determine
the effect of the lattice borders on the statistics of the invaded clusters and
also to characterize the self-organized critical behavior of the invasion
percolation process.Comment: 7 pages, 11 figures, submited for PR
Transition from single-file to two-dimensional diffusion of interacting particles in a quasi-one-dimensional channel
Diffusive properties of a monodisperse system of interacting particles
confined to a \textit{quasi}-one-dimensional (Q1D) channel are studied using
molecular dynamics (MD) simulations. We calculate numerically the mean-squared
displacement (MSD) and investigate the influence of the width of the channel
(or the strength of the confinement potential) on diffusion in finite-size
channels of different shapes (i.e., straight and circular). The transition from
single-file diffusion (SFD) to the two-dimensional diffusion regime is
investigated. This transition (regarding the calculation of the scaling
exponent () of the MSD ) as a
function of the width of the channel, is shown to change depending on the
channel's confinement profile. In particular the transition can be either
smooth (i.e., for a parabolic confinement potential) or rather sharp/stepwise
(i.e., for a hard-wall potential), as distinct from infinite channels where
this transition is abrupt. This result can be explained by qualitatively
different distributions of the particle density for the different confinement
potentials.Comment: 13 pages, 11 figure
Principais aspectos da biologia da mosca do sorgo, Contarinia sorghicola (Coquillett, 1898) (Diptera: Cecidomyiidae).
O mosca do sorgo, Contarinia sorghicola (Coquillet, 1898) (Diptera: Cecidomyiidae) constitui um dos serios problemas para o cultivo do sorgo no Brasil. A sua biologia foi estudada no Sorghum bicolor (L.) Moench em ambiente de laboratorio, para as condicoes de Sete Lagoas, MG, sendo repetida em 5 epocas com intervalo de 20 dias. Observou-se o florescimento das paniculas e o controle de oviposicao de mosca. As plantas foram levadas para o laboratorio e mantidas em provetas com agua. Suas espiguetas foram examinadas diariamente para identificacao das fases do inseto. O periodo medio de incubacao foi de 3,00 +/- 0,00 dias, o larval de 8,20 +/- 0,08 dias e o pupal de 3,77 +/- 0,09 dias. A menor mortalidade deu-se na fase de ovo e a maior na fase de larva
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