27 research outputs found

    CuGaS2 and CuGaS2–ZnS porous layers from solution-processed nanocrystals

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    The manufacturing of semiconducting films using solution-based approaches is considered a low cost alternative to vacuum-based thin film deposition strategies. An additional advantage of solution processing methods is the possibility to control the layer nano/microstructure. Here, we detail the production of mesoporous CuGaS2 (CGS) and ZnS layers from spin-coating and subsequent cross-linking through chalcogen-chalcogen bonds of properly functionalized nanocrystals (NCs). We further produce NC-based porous CGS/ZnS bilayers and NC-based CGS–ZnS composite layers using the same strategy. Photoelectrochemical measurements are used to demonstrate the efficacy of porous layers, and particularly the CGS/ZnS bilayers, for improved current densities and photoresponses relative to denser films deposited from as-produced NCs.Peer ReviewedPostprint (published version

    Tuning branching in ceria nanocrystals

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    Branched nanocrystals (NCs) enable high atomic surface exposure within a crystalline network that provides avenues for charge transport. This combination of properties makes branched NCs particularly suitable for a range of applications where both interaction with the media and charge transport are involved. Herein we report on the colloidal synthesis of branched ceria NCs by means of a ligand-mediated overgrowth mechanism. In particular, the differential coverage of oleic acid as an X-type ligand at ceria facets with different atomic density, atomic coordination deficiency, and oxygen vacancy density resulted in a preferential growth in the [111] direction and thus in the formation of ceria octapods. Alcohols, through an esterification alcoholysis reaction, promoted faster growth rates that translated into nanostructures with higher geometrical complexity, increasing the branch aspect ratio and triggering the formation of side branches. On the other hand, the presence of water resulted in a significant reduction of the growth rate, decreasing the reaction yield and eliminating side branching, which we associate to a blocking of the surface reaction sites or a displacement of the alcoholysis reaction. Overall, adjusting the amounts of each chemical, well-defined branched ceria NCs with tuned number, thickness, and length of branches and with overall size ranging from 5 to 45 nm could be produced. We further demonstrate that such branched ceria NCs are able to provide higher surface areas and related oxygen storage capacities (OSC) than quasi-spherical NCs

    Follistatin as potential therapeutic target in prostate cancer

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    Follistatin is a single-chain glycosylated protein whose primary function consists in binding and neutralizing some members of the transforming growth factor-β superfamily such as activin and bone morphogenic proteins. Emerging evidence indicates that this molecule may also play a role in the malignant progression of several human tumors including prostate cancer. In particular, recent findings suggest that, in this tumor, follistatin may also contribute to the formation of bone metastasis through multiple mechanisms, some of which are not related to its specific activin or bone morphogenic proteins’ inhibitory activity. This review provides insight into the most recent advances in understanding the role of follistatin in the prostate cancer progression and discusses the clinical and therapeutic implications related to these findings

    Surface chemistry and nano-/microstructure engineering on photocatalytic In2S3 nanocrystals

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    Colloidal nanocrystals (NCs) compete with molecular catalysts in the field of homogenous catalysis, offering easier recyclability and a number of potentially advantageous functionalities, such as tunable band gaps, plasmonic properties, or a magnetic moment. Using high-throughput printing technologies, colloidal NCs can also be supported onto substrates to produce cost-effective electronic, optoelectronic, electrocatalytic, and sensing devices. For both catalytic and technological application, NC surface chemistry and supracrystal organization are key parameters determining final performance. Here, we study the influence of the surface ligands and the NC organization on the catalytic properties of In2S3, both as a colloid and as a supported layer. As a colloid, NCs stabilized by inorganic ligands show the highest photocatalytic activities, which we associate with their large and more accessible surfaces. On the other hand, when NCs are supported on a substrate, their organization becomes an essential parameter determining performance. For instance, NC-based films produced through a gelation process provided five-fold higher photocurrent densities than those obtained from dense films produced by the direct printing of NCs.Peer ReviewedPostprint (author's final draft

    TRIM17 and TRIM28 antagonistically regulate the ubiquitination and anti-apoptotic activity of BCL2A1

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    International audienceBCL2A1 is an anti-apoptotic member of the BCL-2 family that contributes to chemoresistance in a subset of tumors. BCL2A1 has a short half-life due to its constitutive processing by the ubiquitin-proteasome system. This constitutes a major tumor-suppressor mechanism regulating BCL2A1 function. However, the enzymes involved in the regulation of BCL2A1 protein stability are currently unknown. Here, we provide the first insight into the regulation of BCL2A1 ubiquitination. We present evidence that TRIM28 is an E3 ubiquitin-ligase for BCL2A1. Indeed, endogenous TRIM28 and BCL2A1 bind to each other at the mitochondria and TRIM28 knock-down decreases BCL2A1 ubiquitination. We also show that TRIM17 stabilizes BCL2A1 by blocking TRIM28 from binding and ubiquitinating BCL2A1, and that GSK3 is involved in the phosphorylation-mediated inhibition of BCL2A1 degradation. BCL2A1 and its close relative MCL1 are thus regulated by common factors but with opposite outcome. Finally, overexpression of TRIM28 or knock-out of TRIM17 reduced BCLA1 protein levels and restored sensitivity of melanoma cells to BRAF-targeted therapy. Therefore, our data describe a molecular rheostat in which two proteins of the TRIM family antagonistically regulate BCL2A1 stability and modulate cell death

    Interoception and Autonomic Correlates during Social Interactions. Implications for Anorexia

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    The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others’ social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others’ socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances

    Hugo Chávez: una década en el poder

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    Una década de Hugo Chávez Frías y su proyecto político en Venezuela trajo consigo un cambio de paradigmas que llama la atención de la sociedad en general. Este libro es el resultado del esfuerzo conjunto de un grupo de académicos de distintas nacionalidades que desde sus líneas de investigación realizan análisis que le brindan al lector elementos para comprender de manera global lo que significa una década de gobierno del Presidente Chávez en Venezuela.Este libro es el resultado del esfuerzo conjunto de un grupo de académicos de distintas nacionalidades que desde sus líneas de investigación realizan análisis que le brindan al lector elementos para comprender de manera global lo que significa una década de gobierno del Presidente Chávez en Venezuela

    Molecular Mechanisms Generating and Stabilizing Terminal 22q13 Deletions in 44 Subjects with Phelan/McDermid Syndrome

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    In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17–74 kb in 9% of the patients. Haploinsufficiency of the SHANK3 gene, confirmed in all rearrangements, is very likely the cause of the major neurological features associated with PMS. SHANK3 mutations can also result in language and/or social interaction disabilities. We determined the breakpoint junctions in 29 cases, providing a realistic snapshot of the variety of mechanisms driving non-recurrent deletion and repair at chromosome ends. De novo telomere synthesis and telomere capture are used to repair terminal deletions; non-homologous end-joining or microhomology-mediated break-induced replication is probably involved in ring 22 formation and translocations; non-homologous end-joining and fork stalling and template switching prevail in cases with interstitial 22q13.3. For the first time, we also demonstrated that distinct stabilizing events of the same terminal deletion can occur in different early embryonic cells, proving that terminal deletions can be repaired by multistep healing events and supporting the recent hypothesis that rare pathogenic germline rearrangements may have mitotic origin. Finally, the progressive clinical deterioration observed throughout the longitudinal medical history of three subjects over forty years supports the hypothesis of a role for SHANK3 haploinsufficiency in neurological deterioration, in addition to its involvement in the neurobehavioral phenotype of PMS

    Ptolemy III Euergetes' Reign of Egypt from 246 to 241 BC.

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    La tesi di dottorato consiste in una ricostruzione del regno di Tolemeo III Evergete d’Egitto dall’assunzione del titolo regale nel 246 a.C. fino alla conclusione della guerra laodicea nel 241 a.C.. Preliminarmente vengono presentate le principali fonti storiografiche, letterarie, papiracee, epigrafiche e numismatiche a nostra disposizione per la ricostruzione del regno dell’Evergete. Un’intera sezione è dedicata esclusivamente alle opere frammentarie di autori collocabili tra la seconda metà del III e la prima metà del II secolo a.C.. Il lavoro procede con una ricostruzione delle vicende biografiche di Tolemeo III fino al 246 a.C., con una discussione circa l’ancora incerta identificazione di quest’ultimo e con una presentazione dei principali membri della famiglia reale lagide e del ruolo politico da essi svolto. Successivamente vengono analizzate nel dettaglio le tappe della guerra laodicea e vengono offerti una visione complessiva dei territori sotto il controllo lagide nel 245 e un bilancio sui rapporti di forza tra le potenze lagide e seleucide al termine del conflitto. Infine, viene esaminata la politica interna di Tolemeo III attraverso la presentazione dei provvedimenti in ambito giudiziario, sociale, amministrativo, fiscale, economico e militare, con un focus particolare sul processo di legittimazione del potere messo in atto dal sovrano.The aim of this thesis is to reconstruct Ptolemy III’s reign of Egypt, from the assumption of the royal title in 246 BC up to the end of the Laodicean War in 241 BC. First of all, a presentation of the main historiographic, literary, papyracean, epigraphic and numismatic sources at disposal for a reconstruction of Ptolemy III’s reign is made. An entire section is dedicated to the fragmentary works dateable to a range between the second half of the 3rd century BC and the first half of the 2nd century BC. Then, the research focuses on the reconstruction of Euergetes’ biography until 246 BC, the discussed identification of the king and the presentation of the main royal family’s members and of their political role. Furthermore the Laodicean War’s stages are analysed and an overall view of the areas under Lagid control in 245 is offered as well as an assessment of the balance of power between Lagids and Seleucids at the end of the war. Finally, the thesis analyses the measures taken by Ptolemy III in the judicial, social, administrative, fiscal, economic and military fields. A focus is provided on the process of legitimising power implemented by the Euergetes
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