1,881 research outputs found
Photochemical cross-linking study of polymers containing diacetylene groups in their main chain and azobenzene compounds as pendant groups
Photochemical cross-linking studies at different temperatures (room temperature, Tg and maximum exothermal of crosslinking peak) are shown for three series of polymers containing diacetylene-groups in the main chain and polar chromophores derived from benzene, azo- and di-azobenzene, as pendant groups. We establish the optimal irradiation time and temperature that permit them being poled and cross-linked with minimal dye-degradation. The degradation process was followed by a diminution of the respective maximum absorption peak. These conditions could extend the mean life-time of the second order nonlinear optical properties, studied previously. Photochemical cross-linking at each polymer´s Tg (50-130°C) was the most convenient process. It took less than 10 min and was monitored by IR spectroscop
ALMA polarimetry measures magnetically aligned dust grains in the torus of NGC 1068
The obscuring structure surrounding active galactic nuclei (AGN) can be
explained as a dust and gas flow cycle that fundamentally connects the AGN with
their host galaxies. This structure is believed to be associated with dusty
winds driven by radiation pressure. However, the role of magnetic fields, which
are invoked in almost all models for accretion onto a supermassive black hole
and outflows, is not thoroughly studied. Here we report the first detection of
polarized thermal emission by means of magnetically aligned dust grains in the
dusty torus of NGC 1068 using ALMA Cycle 4 polarimetric dust continuum
observations (, pc; 348.5 GHz, m). The polarized torus
has an asymmetric variation across the equatorial axis with a peak polarization
of \% and position angle of (B-vector) at
pc east from the core. We compute synthetic polarimetric observations of
magnetically aligned dust grains assuming a toroidal magnetic field and
homogeneous grain alignment. We conclude that the measured 860 m continuum
polarization arises from magnetically aligned dust grains in an optically thin
region of the torus. The asymmetric polarization across the equatorial axis of
the torus arises from 1) an inhomogeneous optical depth, and 2) a variation of
the velocity dispersion, i.e. variation of the magnetic field turbulence at
sub-pc scales, from the eastern to the western region of the torus. These
observations and modeling constrain the torus properties beyond spectral energy
distribution results. This study strongly supports that magnetic fields up to a
few pc contribute to the accretion flow onto the active nuclei.Comment: 19 pages, 11 figures (Accepted for Publication to ApJ
Análisis del funcionamiento vocal en los entrenadores de la Federación Deportiva del Azuay de la ciudad de Cuenca, período agosto 2022 - febrero 2023
El entrenador deportivo tiene como herramienta fundamental su voz, medio importante para su comunicación, el uso inapropiado del tono e intensidad al momento de su entrenamiento y competencia provoca un mal funcionamiento de la misma. Acciones que provocan ciertas disfonías en su ámbito laboral. Objetivo: Analizar el funcionamiento vocal en los entrenadores de la “Federación deportiva del Azuay” de la ciudad de Cuenca, periodo agosto 2022 - febrero 2023. Metodología: Se realizó un estudio del mal funcionamiento vocal que existe en los entrenadores de FDA, donde se usó un formulario y un aplicativo de pruebas subjetivas y objetivas de la voz. Donde los resultados fueron analizados mediante el programa SPSS STATISTICS, versión gratuita 15.0. Resultados: Estudio descriptivo realizado a 51 entrenadores deportivos de la FDA, obteniendo un dominio en el género masculino con un 68.6% y un rango de edad entre los 20 y 40 años representando el 62.7% de la muestra estudiada. Con el uso de baterías fonoaudiológicas subjetivas y objetivas de la voz, donde se pudo observar que existe mayor prevalencia de alteración vocal leve de 72.5% en el VHI y 58.8% en el GRABSI, con un 88.2% con disfonía según el PRAAT. Los entrenadores con mayor afección de la voz representan el 49% de la muestra. Conclusión: El estudio reveló una mayor incidencia en cuanto el mal uso vocal en los entrenadores del sexo masculino, viéndose alterado las cualidades vocálicas grado leve en las disciplinas de campo. Resultados esperados: Mal funcionamiento vocal en los entrenadores deportivos del Azuay.The sports coaches` voice is an essential tool for them. It is an important means for communication. An inappropriate use of tone and intensity during training and competitions might cause a malfunction of it. Sport coaches might even be affected by dysphonia. Objective: To analyze the vocal function of the coaches of Azuay Sports Federation in the city of Cuenca during August 2022 – February 2023. Methodology: A study of vocal cord dysfunction of FDA coaches was carried out. A form and an application featuring subjective and objective voice quality tests were used. The results were analyzed using the SPSS STATISTICS program, free version 15.0. Results: This is a descriptive study carried out on fifty-one FDA sports coaches: the male gender showed a higher percentage (68.6 %) in the 20-to-40 age range, which represents 62.7% of the sample. Using subjective and objective speech and hearing therapy batteries, it was detected that there is a higher prevalence of mild vocal alteration of 72.5% in the VHI and 58.8% in the GRBASI scale, and 88.2% of dysphonia according to the Praat program. The coaches with the greatest voice impairment represent 49 % of the sample. Conclusion: Vocal minuses of Azuay sports coaches showed a higher prevalence in males, with a slight voice alteration in field disciplines. Expected results: Vocal cord dysfunction in Azuay sports coaches.0009-0004-5418-1529Licenciado en FonoaudiologíaCuenc
Relationship between serum levels of triglycerides and vascular inflammation, measured as COX-2, in arteries from diabetic patients: a translational study
Role of TGF-β1 and MAP Kinases in the Antiproliferative Effect of Aspirin in Human Vascular Smooth Muscle Cells
We aimed to test the antiproliferative effect of acetylsalicylic acid (ASA) on vascular smooth muscle cells (VSMC) from bypass surgery patients and the role of transforming growth factor beta 1 (TGF-beta1).VSMC were isolated from remaining internal mammary artery from patients who underwent bypass surgery. Cell proliferation and DNA fragmentation were assessed by ELISA. Protein expression was assessed by Western blot. ASA inhibited BrdU incorporation at 2 mM. Anti-TGF-beta1 was able to reverse this effect. ASA (2 mM) induced TGF-beta1 secretion; however it was unable to induce Smad activation. ASA increased p38(MAPK) phosphorylation in a TGF-beta1-independent manner. Anti-CD105 (endoglin) was unable to reverse the antiproliferative effect of ASA. Pre-surgical serum levels of TGF-beta1 in patients who took at antiplatelet doses ASA were assessed by ELISA and remained unchanged.In vitro antiproliferative effects of aspirin (at antiinflammatory concentration) on human VSMC obtained from bypass patients are mediated by TGF-beta1 and p38(MAPK). Pre-surgical serum levels of TGF- beta1 from bypass patients who took aspirin at antiplatelet doses did not change
Age-dependent defective TGF-beta1 signaling in patients undergoing coronary artery bypass grafting
Background: Transforming growth factor beta (TGF-beta 1) is a pleiotropic cytokine, which is deregulated in atherosclerosis; however the role of age in this process is unknown. We aimed to assess whether TGF-beta 1 signaling is affected by age. Methods: Vascular smooth muscle cells (VSMC) were obtained from patients undergoing abdominal surgery. Levels of TGF-beta 1 were measured by ELISA in sera from 169 patients undergoing coronary artery bypass grafting (CABG). The p27 expression was determined by Western blot from internal mammary arteries (IMA) obtained from CABG patients (n = 13). In VSMC from these patients undergoing abdominal surgery, secretion of TGF-beta 1 was determined by ELISA of cell-conditioned media. Results: In VSMC from aged patients we observed a lower TGF-beta 1 secretion, measured as TGF-beta 1 concentration in cell conditioned medium (p < 0.001). This effect was correlated to an age-dependent decrease of p27 expression in IMA from aged CABG patients. In a similar manner, there was an age-dependent decrease of serum TGF-beta 1 levels in CABG patients (p = 0.0195). Conclusions: VSMC from aged patients showed a higher degree of cellular senescence and it was associated to a lower TGF-beta 1 secretion and signaling.S
Synthesis by wet chemistry and characterization of LiNbO3 nanoparticles
Actually, lithium niobate (LiNbO3) has been used for optical wavelength conversion and ultrafast optical signal processing because of its outstanding rapid nonlinear optical response behavior, low switching power and broad conversion bandwidth. LiNbO3nanoparticles, which belong to the ferroelectric oxide class, were synthesized by chemical reaction with wetchemistry. Their sizedistributionwascenteredaround200 nm. Xray diffraction (XRD) and scanning electron microscopy (SEM) were used to further investigate the quality of the obtained LiNbO3powders.The present work shows thatby employingthis chemical method the correct stoichiometric phasewas obtained. This wascorroborated by XPS (X-Ray Photoelectron Spectroscopy) results. Also, the nanoparticles showed a defined crystallinity and uniform morphology. This way of obtaining nanoparticles is innovative because of its low cost and simple way to reproduce it. It isan important method of increasing the surfacearea, controlling thephase purityand reducing theparticle size distribution. The samples were obtained under low temperature annealing at500, 650 and 800 ºC. Those features can be controlled using variables such temperature, time of synthesis,and calcination. In previous worksit wasfound that hydrothermal methods offer many advantages over conventional ceramic synthesis methods
CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells
The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1low cells present a migratory and invasive phenotype, while EWSR1::FLI1high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.This project was funded by Instituto de Salud Carlos III, grant numbers PI20CIII/00020, DTS18CIII/00005, Asociación Pablo Ugarte, grant numbers TRPV205/18; Asociación Candela Riera, Asociación Todos Somos Iván & Fundación Sonrisa de Alex, grant numbers TVP333-19, TVP-1324/15; ASION, grant number TVP141/17. Enrique Fernández-Tabanera is supported by Asociación Candela Riera, Asociación Todos Somos Iván & Fundación Sonrisa de Alex, Saint T. Cervera is supported by Asociación Pablo Ugarte and Raquel M. Melero is supported by a CIBERER contract.S
- …