1,304 research outputs found
El teléfono móvil: disponibilidad, usos y relaciones por parte de los adolescentes entre 12 y 16 años
Presentamos los resultados de una investigación sobre el uso, la
disponibilidad y algunos aspectos relativos a las relaciones que
se establecen con diferentes personas en torno al teléfono móvil
en una muestra de adolescentes (N=1211) entre 12 y 16 años de
la provincia de Girona. Los resultados ponen de manifiesto la
existencia de diferencias de género en cuanto a su disposición y
uso, siendo las chicas las que en mayor porcentaje poseen un
móvil y más horas dedican a usarlo. Los adolescentes prefieren
hablar sobre lo que hacen con el móvil con los iguales, seguido
de los hermanos o las hermanas y, en último lugar, con los adultos
(progenitores y profesores o profesoras). Finalmente, se analiza
cómo los adolescentes se muestran más interesados por e informados
sobre Internet y el móvil en comparación con los
otros cuatro medios audiovisuales explorados (televisión, ordenador,
juegos para ordenador y videojuegos)
Molecular Interactions of Prodiginines with the BH3 Domain of Anti-Apoptotic Bcl-2 Family Members
Prodigiosin and obatoclax, members of the prodiginines family, are small molecules with anti-cancer properties that are
currently under preclinical and clinical trials. The molecular target(s) of these agents, however, is an open question.
Combining experimental and computational techniques we find that prodigiosin binds to the BH3 domain in some BCL-2
protein families, which play an important role in the apoptotic programmed cell death. In particular, our results indicate
a large affinity of prodigiosin for MCL-1, an anti-apoptotic member of the BCL-2 family. In melanoma cells, we demonstrate
that prodigiosin activates the mitochondrial apoptotic pathway by disrupting MCL-1/BAK complexes. Computer simulations
with the PELE software allow the description of the induced fit process, obtaining a detailed atomic view of the molecular
interactions. These results provide new data to understand the mechanism of action of these molecules, and assist in the
development of more specific inhibitors of anti-apoptotic BCL-2 proteins.Spanish government and the European Union (FIS-PI10/00338) and from the ERC-2009-Adg
25027-PELE European project
In-depth mesocrystal formation analysis of microwave-assisted synthesis of LiMnPO4nanostructures in organic solution
In the present work, we report on the preparation of LiMnPO4 (lithiophilite) nanorods and mesocrystals composed of self-assembled rod subunits employing microwave-assisted precipitation with processing times on the time scale of minutes. Starting from metal salt precursors and H3PO4 as phosphate source, single-phase LiMnPO4 powders with grain sizes of approx. 35 and 65 nm with varying morphologies were obtained by tailoring the synthesis conditions using rac-1-phenylethanol as solvent. The mesocrystal formation, microstructure and phase composition were determined by electron microscopy, nitrogen physisorption, X-ray diffraction (including Rietveld refinement), dynamic light scattering, X-ray absorption and X-ray photoelectron spectroscopy, and other techniques. In addition, we investigated the formed organic matter by gas chromatography coupled with mass spectrometry in order to gain a deeper understanding of the dissolution\u2013precipitation process. Also, we demonstrate that the obtained LiMnPO4 nanocrystals can be redispersed in polar solvents such as ethanol and dimethylformamide and are suitable as building blocks for the fabrication of nanofibers via electrospinning
Chromatin and DNA methylation dynamics during retinoic acid-induced RET gene transcriptional activation in neuroblastoma cells.
Although it is well known that RET gene is strongly activated by retinoic acid (RA) in neuroblastoma cells, the mechanisms underlying such activation are still poorly understood. Here we show that a complex series of molecular events, that include modifications of both chromatin and DNA methylation state, accompany RA-mediated RET activation. Our results indicate that the primary epigenetic determinants of RA-induced RET activation differ between enhancer and promoter regions. At promoter region, the main mark of RET activation was the increase of H3K4me3 levels while no significant changes of the methylation state of H3K27 and H3K9 were observed. At RET enhancer region a bipartite chromatin domain was detected in unstimulated cells and a prompt demethylation of H3K27me3 marked RET gene activation upon RA exposure. Moreover, ChIP experiments demonstrated that EZH2 and MeCP2 repressor complexes were associated to the heavily methylated enhancer region in the absence of RA while both complexes were displaced during RA stimulation. Finally, our data show that a demethylation of a specific CpG site at the enhancer region could favor the displacement of MeCP2 from the heavily methylated RET enhancer region providing a novel potential mechanism for transcriptional regulation of methylated RA-regulated loci
Small molecule anionophores promote transmembrane anion permeation matching CFTR activity
Anion selective ionophores, anionophores, are small molecules capable of facilitating the
transmembrane transport of anions. Inspired in the structure of natural product prodigiosin, four
novel anionophores 1a-d, including a 1,2,3-triazole group, were prepared. These compounds proved
highly efficient anion exchangers in model phospholipid liposomes. The changes in the hydrogen bond
cleft modified the anion transport selectivity exhibited by these compounds compared to prodigiosin
and suppressed the characteristic high toxicity of the natural product. Their activity as anionophores
in living cells was studied and chloride efflux and iodine influx from living cells mediated by these
derivatives was demonstrated. These compounds were shown to permeabilize cellular membranes
to halides with efficiencies close to the natural anion channel CFTR at doses that do not compromise
cellular viability. Remarkably, optimal transport efficiency was measured in the presence of pH
gradients mimicking those found in the airway epithelia of Cystic Fibrosis patients. These results
support the viability of developing small molecule anionophores as anion channel protein surrogates
with potential applications in the treatment of conditions such as Cystic Fibrosis derived from the
malfunction of natural anion transport mechanisms.European Union’s Horizon 2020 research and innovation programme under grant agreement No. 667079, La Marató de TV3 Foundation (20132730), Consejería de Educación de la Junta de Castilla y León (Projects BU340U13 and BU092U16
Serratamolide is a hemolytic factor produced by Serratia marcescens
Serratia marcescens is a common contaminant of contact lens cases and lenses. Hemolytic factors of S. marcescens contribute to the virulence of this opportunistic bacterial pathogen. We took advantage of an observed hyper-hemolytic phenotype of crp mutants to investigate mechanisms of hemolysis. A genetic screen revealed that swrW is necessary for the hyper-hemolysis phenotype of crp mutants. The swrW gene is required for biosynthesis of the biosurfactant serratamolide, previously shown to be a broad-spectrum antibiotic and to contribute to swarming motility. Multicopy expression of swrW or mutation of the hexS transcription factor gene, a known inhibitor of swrW expression, led to an increase in hemolysis. Surfactant zones and expression from an swrW-transcriptional reporter were elevated in a crp mutant compared to the wild type. Purified serratamolide was hemolytic to sheep and murine red blood cells and cytotoxic to human airway and corneal limbal epithelial cells in vitro. The swrW gene was found in the majority of contact lens isolates tested. Genetic and biochemical analysis implicate the biosurfactant serratamolide as a hemolysin. This novel hemolysin may contribute to irritation and infections associated with contact lens use. © 2012 Shanks et al
Residential electricity pricing in China
The paper aims to evaluate the implications of the new residential pricing system in China by examining price and income elasticity of demand by different household types. We use pre-reform annual panel data for 29 provinces over a fourteen year period, from 1998 to 2011, applying feasible generalize least squares models. The price and income elasticities for household sector are -0.412, and 1.476 at nation level, -0.300 and 1.550 in urban areas and -0.522 and 1.093 in rural areas respectively. With regional effects, the price and income elasticities are -0.146 and 1.286 for urban households in coastal provinces and -0.772 and 1.259 for urban households in inland provinces respectively. The empirical results reveal that there is important heterogeneity in the responsiveness to electricity price changes according to household income level and location
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