16 research outputs found

    Optical properties of BaTiO3: determination of the absorption coefficient and its correlation with the material photo-response

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    The photocontrol of ferroelectric properties has recently attracted notable attention as an effective alternative methodology to electric polarization switching. Specifically, it has been reported that macroscopic polarization, and consequently its related properties, can be tuned by means of visible light in a ferroelectric crystal. The implication of this discovery for the macroscopic properties of a ferroelectric crystal has also been explored, showing that the local movement of domain walls is noted at the macroscopic scale, for instance, as a change in dielectric properties. This new light-matter coupling supposes a non-contact external control of the macroscopic response in these functional materials. Although the discovered phenomenon may open a pathway to find a next generation of photo-simulated ferroelectric devices, the studies carried out until today are only the first step of a long way. In this context, this project aims to answer some issues that remain to be solved concerning this phenomenon. In particular, the project focuses on the correlation between the optical properties of the active material and its photo-response, which is still unknown. The project has a noticeable experimental character. Custom experimental setups are developed to carry out optical measurements such as absorbance, reflectance and trasmittance for different samples changing some variables. Results evidenced that it was possible to correlate this photo response with the absorption coefficient. Both parameters follow the same tendency. The initial hypothesis is therefore proved, the photo-response observed in BTO is directly related to the light absorptioncapacity of the charged domain walls exhibited in these type of materials

    A Human iPSC-derived 3D platform using primary brain cancer cells to study drug development and personalized medicine

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    Abstract A high throughput histology (microTMA) platform was applied for testing drugs against tumors in a novel 3D heterotypic glioblastoma brain sphere (gBS) model consisting of glioblastoma tumor cells, iPSC-derived neurons, glial cells and astrocytes grown in a spheroid. The differential responses of gBS tumors and normal neuronal cells to sustained treatments with anti-cancer drugs temozolomide (TMZ) and doxorubicin (DOX) were investigated. gBS were exposed to TMZ or DOX over a 7-day period. Untreated gBS tumors increased in size over a 4-week culture period, however, there was no increase in the number of normal neuronal cells. TMZ (100 uM) and DOX (0.3 uM) treatments caused ~30% (P~0.07) and ~80% (P < 0.001) decreases in the size of the tumors, respectively. Neither treatment altered the number of normal neuronal cells in the model. The anti-tumor effects of TMZ and DOX were mediated in part by selective induction of apoptosis. This platform provides a novel approach for screening new anti-glioblastoma agents and evaluating different treatment options for a given patient

    Real-world evidence for secukinumab in UK patients with psoriatic arthritis or radiographic axial spondyloarthritis: interim 2-year analysis from SERENA

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    Objectives: The aim was to evaluate retention rates for secukinumab in patients with active PsA or radiographic axial spondyloarthritis (r-axSpA) treated in routine UK clinical practice. Methods: SERENA (CAIN457A3403) is an ongoing, non-interventional, international study of patients with moderate-to-severe chronic plaque psoriasis, active PsA or active r-axSpA, who had received secukinumab for ≥16 weeks before enrolment. The primary objective of this interim analysis was to assess treatment retention rates in patients with PsA or r-axSpA who were enrolled and followed for ≥2 years at centres in the UK. The safety analysis set includes all patients who received at least one dose of secukinumab. The target population set includes all patients who fulfilled the patient selection criteria. Results: The safety set comprised 189 patients (PsA, n = 81; r-axSpA, n = 108), and the target population set comprised 183 patients (PsA, n = 78; r-axSpA, n = 105). In the safety set, 107 patients (45 of 81 with PsA and 62 of 108 with r-axSpA) had previously received a biologic agent. Retention rates were similar between patients with PsA and r-axSpA after 1 year (PsA 91.0%, 95% CI: 84.0, 98.0; r-axSpA 89.2%, 95% CI: 82.7, 95.7) and 2 years (PsA 77.6%, 95% CI: 67.6, 87.7; r-axSpA 76.2%, 95% CI: 67.4, 85.0) of observation. Overall, 17.5% of patients (33 of 189) experienced at least one treatment-related adverse event, and 12.7% of patients (24 of 189) discontinued secukinumab because of adverse events. Conclusion: This analysis of real-world data from the UK demonstrates high retention rates for secukinumab over 2 years in patients with PsA or r-axSpA, with a favourable safety profile

    Light-induced strain and its correlation with the optical absorption at charged domain walls in polycrystalline ferroelectrics

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    Photostrictive materials have a growing interest because of their great potential as light-driven actuators, among other optomechanical applications. In this context, the optical control of macroscopic strain in ferroelectrics has recently attracted remarkable attention as an effective alternative to the conventional electric control of strain. Here, a clear correlation between optical absorption and light-induced strain in polycrystalline BaTiO3 is shown. Specifically, the grain size and the sample thickness dependence of optical absorption when the material is irradiated with energy photons lower than the band gap evidence that light absorption at charged domain walls is the core of the observed photo-response in ferroelectrics. The photoinduced electronic reconstruction phenomenon is proposed as the primary physical mechanism for light absorption at charged domain walls. Results open a new pathway to designing ferroelectric-based devices with new functionalities like thickness gradient-based photo-controlled nanoactuators

    Light-induced strain and its correlation with the optical absorption at charged domain walls in polycrystalline ferroelectrics

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    Photostrictive materials have a growing interest because of their great potential as light-driven actuators, among other optomechanical applications. In this context, the optical control of macroscopic strain in ferroelectrics has recently attracted remarkable attention as an effective alternative to the conventional electric control of strain. Here, a clear correlation between optical absorption and light-induced strain in polycrystalline BaTiO3 is shown. Specifically, the grain size and the sample thickness dependence of optical absorption when the material is irradiated with energy photons lower than the band gap evidence that light absorption at charged domain walls is the core of the observed photo-response in ferroelectrics. The photoinduced electronic reconstruction phenomenon is proposed as the primary physical mechanism for light absorption at charged domain walls. Results open a new pathway to designing ferroelectric-based devices with new functionalities like thickness gradient-based photo-controlled nanoactuators.Postprint (published version

    Eficiencia productiva y económica de la suplementación de terneros al pie de la madre. Comunicación

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    PosterEvaluar la implementación de un sistema de creep feeding, utilizando suplementación con cantidades diarias relativamente bajas, para aumentar el rendimiento animal y calcular el margen bruto de la práctica.EEA Colonia BenitezFil: Prieto, Paula Noelia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Prieto, Paula Noelia. Universidad Nacional de Formosa. Facultad de Recursos Naturales; ArgentinaFil: Balbuena, Osvaldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Balbuena, Osvaldo. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Pellerano, Liliana Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Vispo, Pablo Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Stahringer, Rodolfo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Rossner, Maria Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; ArgentinaFil: Rossner, Maria Victoria. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Pamies, Marcelo Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Colonia Benítez; Argentin

    Microfluidic‐assisted blade coating of compositional libraries for combinatorial applications: the case of organic photovoltaics

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    Microfluidic technologies are highly adept at generating controllable compositional gradients in fluids, a feature that has accelerated the understanding of the importance of chemical gradients in biological processes. That said, the development of versatile methods to generate controllable compositional gradients in the solid‐state has been far more elusive. The ability to produce such gradients would provide access to extensive compositional libraries, thus enabling the high‐throughput exploration of the parametric landscape of functional solids and devices in a resource‐, time‐, and cost‐efficient manner. Herein, the synergic integration of microfluidic technologies is reported with blade coating to enable the controlled formation of compositional lateral gradients in solution. Subsequently, the transformation of liquid‐based compositional gradients into solid‐state thin films using this method is demonstrated. To demonstrate efficacy of the approach, microfluidic‐assisted blade coating is used to optimize blending ratios in organic solar cells. Importantly, this novel technology can be easily extended to other solution processable systems that require the formation of solid‐state compositional lateral gradients

    Molecular characterization of epithelial-mesenchymal transition and medical treatment related-genes in non-functioning pituitary neuroendocrine tumors

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    Different medical therapies have been developed for pituitary adenomas. However, Non-Functioning Pituitary Neuroendocrine Tumors (NF-PitNET) have shown little response to them. Furthermore, epithelial-mesenchymal transition (EMT) has been linked to resistance to medical treatment in a significant number of tumors, including pituitary adenomas. We aimed to evaluate the expression of EMT-related markers in 72 NF-PitNET and 16 non-tumoral pituitaries. To further explore the potential usefulness of medical treatment for NF-PitNET we assessed the expression of somatostatin receptors and dopamine-associated genes. We found that SNAI1, SNAI2, Vimentin, KLK10, PEBP1, Ki-67 and SSTR2 were associated with invasive NF-PitNET. Furthermore, we found that the EMT phenomenon was more common in NF-PitNET than in GH-secreting pituitary tumors. Interestingly, PEBP1 was overexpressed in recurrent NF-PitNET, and could predict growth recurrence with 100% sensitivity but only 43% specificity. In parallel with previously reported studies, SSTR3 is highly expressed in our NF-PitNET cohort. However, SSTR3 expression is highly heterogeneous among the different histological variants of NF-PitNET with very low levels in silent corticotroph adenomas. NF-PitNET showed an enhanced EMT phenomenon. SSTR3 targeting could be a good therapeutic candidate in NF-PitNET except for silent corticotroph adenomas, which express very low levels of this receptor. In addition, PEBP1 could be an informative biomarker of tumor regrowth, useful for predictive medicine in NF-PitNET

    Effect of nitrogen addition and litter removal on understory vegetation, soil mesofauna, and litter decomposition in loblolly pine plantations in subtropical Argentina

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    Loblolly pine monocultures have been increasingly expanding in the Atlantic Forest of South America especially in northern Argentina. Pine plantations can modify understory vegetation and soil characteristics due to the management practices and to the dense mulch of pine needles that develop in the forest floor that could affect soil biota and ecosystem processes. Nitrogen (N) addition as expected as atmospheric deposition can also contribute to these changes. The aim of this study was to assess the effect of litter removal and low levels of N addition on understory regeneration, soil mesofauna abundance, and leaf litter decomposition. For this purpose, a completely randomized block design was used. Nitrogen addition had significant effects on understory regeneration promoting creeping herbs, graminoids and shrubs life forms affecting tree establishment and growth. Litter removal treatment showed the same pattern but only promoting the creeping herbs that could also have affected tree species. Decomposition decreased due to litter removal and was slightly increased by N addition. The addition of N decreased the abundance of mesofauna in the mulch, especially Symphypleone (a suborder of Collembola), but the abundance of the soil communities was not affected. Litter removal had a strong impact on these communities because most individuals and species of the mesofauna are present in the litter and not in the soil. This is one of the first studies analyzing the effect of low amounts of N addition and litter removal in subtropical pine plantations and contribute to understand potential impacts of increasing N deposition on biodiversity and soil processes, and to select organisms that may help as bioindicators in assessing impacts on ecological functions in productive ecosystems.Fil: Trentini, Carolina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Villagra, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Gomez Pamies, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Bernava Laborde, V.. Administración de Parques Nacionales; ArgentinaFil: Bedano, José Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Geología; ArgentinaFil: Campanello, Paula Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; Argentina. Universidad Nacional de la Patagonia "san Juan Bosco". Facultad de Ingeniería - Sede Esquel; Argentin

    A human brain microphysiological system derived from induced pluripotent stem cells to study neurological diseases and toxicity

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    Human in vitro models of brain neurophysiology are needed to investigate molecular and cellular mechanisms associated with neurological disorders and neurotoxicity. We have developed a reproducible iPSC-derived human 3D brain microphysiological system (BMPS), comprised of differentiated mature neurons and glial cells (astrocytes and oligodendrocytes) that reproduce neuronal-glial interactions and connectivity. BMPS mature over eight weeks and show the critical elements of neuronal function: synaptogenesis and neuron-to-neuron (e.g., spontaneous electric field potentials) and neuronal-glial interactions (e.g., myelination), which mimic the microenvironment of the central nervous system, rarely seen in vitro before. The BMPS shows 40% overall myelination after 8 weeks of differentiation. Myelin was observed by immunohistochemistry and confirmed by confocal microscopy 3D reconstruction and electron microscopy. These findings are of particular relevance since myelin is crucial for proper neuronal function and development. The ability to assess oligodendroglial function and mechanisms associated with myelination in this BMPS model provide an excellent tool for future studies of neurological disorders such as multiple sclerosis and other demyelinating diseases. The BMPS provides a suitable and reliable model to investigate neuron-neuroglia function as well as pathogenic mechanisms in neurotoxicology.publishe
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