270 research outputs found

    La solidaridad internacional, principio irrenunciable del pueblo cubano

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    The consequent attitude of the Cuban Revolution in the materialization of the principle of International Solidarityis the object of analysis in the article, sharing what we have, not what we have in abundance. Also,highlight the position of Cuba always aligned with just causes, the defense and practice of humanism. Atthe same time, we intend to consider values as a theory and practice of the construction of socialism, arguingthat it is the most concrete evidence of the product of the dialectical conjunction of Fidel Castro Ruzand his people, who has continued to follow him convinced of the rightness of the work they have starredtogether. Starting from these assumptions, we reflect on moments and events that illustrate through examplesand historical evidence the Cuban presence in the defense of freedom, independence and self-determinationof the peoples, as well as unconditional help in Health, Education and no less transcendentDefense fields. All of the above has favored the improvement of their quality of life.La consecuente actitud de la Revolución Cubana en la materialización del principio de la solidaridad internacionales objeto de análisis en el artículo, compartir lo que tenemos, no lo que nos sobra. Asimismo,destacar la posición de Cuba alineada siempre en el lugar de las causas justas, la defensa y práctica delhumanismo. Pretendemos al mismo tiempo considerar el valor como teoría y práctica de la construccióndel socialismo, argumentando que es la evidencia más concreta de que es el producto de la conjuncióndialéctica de Fidel Castro Ruz y de su pueblo, que lo ha seguido convencido de la justeza de la obra quejuntos han protagonizado. Partiendo de estos presupuestos reflexionamos acerca de momentos y hechosque ilustren a través de ejemplos y evidencias históricas la presencia cubana en defensa de la libertad,la independencia y autodeterminación de los pueblos, así como la ayuda incondicional en salud, educacióny no menos trascendente en el terreno de la defensa, contribuyendo a elevar los índices de salud,educación, entre otros y de esta forma favorecer el mejoramiento de la calidad de vida de los mismos

    Analysis of grass pollen concentrations in the atmosphere of several spanish sites

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    Effect of the Fe Nanoparticles Generated by Pulsed Plasma in Liquid in the Catalyzed Ozone Removal of Phenolphthalein

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    We have synthesized, in this work, zero valent iron (ZVI) nanoparticles to improve the efficiency of degradation of phenolphthalein catalyzed by ozone in aqueous solution. The Fe nanoparticles were obtained using the pulsed plasma in liquid (PPL) method with water as the liquid medium. Such nanoparticles have a mean size of 12 nm and are composed of ~80% Fe0, while the rest are a mixture of Fe+2 and Fe+3 oxides. The degradation of phenolphthalein was carried on a glass reactor injecting a constant amount of ozone and introducing different concentrations of Fe nanoparticles to the system. When using pure ozone, the percentage of degradation of phenolphthalein measured by colorimetry after one hour of reaction was 84%. However, when Fe nanoparticles are used, such percentage can be as high as 98% in 50 minutes of reaction. Furthermore, the degradation rate constant was 0.0334 min−1 with only ozone and it can be as high as 0.0733 min−1 with Fe nanoparticles. Finally, the total mineralization of phenolphthalein was obtained by total organic carbon (TOC) determinations. It is shown that when using only ozone, we obtained a percentage of mineralization of 49% and 96% when using the highest concentration of Fe nanoparticles

    SDSS-IV MANGA: Spatially Resolved Star Formation Main Sequence and LI(N)ER Sequence

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    We present our study on the spatially resolved H_alpha and M_star relation for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We show that the star formation rate surface density (Sigma_SFR), derived based on the H_alpha emissions, is strongly correlated with the M_star surface density (Sigma_star) on kpc scales for star- forming galaxies and can be directly connected to the global star-forming sequence. This suggests that the global main sequence may be a consequence of a more fundamental relation on small scales. On the other hand, our result suggests that about 20% of quiescent galaxies in our sample still have star formation activities in the outer region with lower SSFR than typical star-forming galaxies. Meanwhile, we also find a tight correlation between Sigma_H_alpha and Sigma_star for LI(N)ER regions, named the resolved "LI(N)ER" sequence, in quiescent galaxies, which is consistent with the scenario that LI(N)ER emissions are primarily powered by the hot, evolved stars as suggested in the literature.Comment: 6 pages, 4 figures. ApJ Letter accepte

    Polymer waste materials as fillers in polymer mortars: experimental and finite elements simulation

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    Serious environmental problems are due to large amounts of polymer waste, which are mostly thrown into landfills. As we known, polymer composites has been used to produce a variety of products like acid tanks, manholes, drains, highway median barriers, and so forth. One option is to use waste polymers as aggregates in polymer composites. In this work, waste polymers (PET, polycarbonate and automotive tires), partially replaced silica sand in polyester based mortar. Waste particles (0.7–2.36 mm), in concentrations of 1, 2 and 3% by weight, were used. The polymer mortar specimens were subjected to compressive and flexural tests, and the elasticity modulus was calculated. In addition, mechanical values were calculated by Finite Element Method (FEM), and compared with experimental data. Surface morphology and degree of crystallinity of waste particles were analyzed by SEM and XRD techniques, respectively. The results show improvement on the mechanical strength (up to 20%) for polymer mortar with waste PET; but lower mechanical values when adding polycarbonate or tire particles, compared to control mortar. These mechanical results can be related to the crystallinity degree, because PET particles shown higher crystallinity than those for polycarbonate and tire particles. This work is an alternative to reduce environmental contamination through to use waste polymers as fillers in polymer mortars. Keywords: Polymer waste, Polymer mortar, Polyethylene terephthalate, Polycarbonate, Tire rubber, Mechanical propertie

    A Comparative Electrochemical-Ozone Treatment for Removal of Phenolphthalein

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    The degradation of aqueous solutions containing phenolphthalein was carried out using ozone and electrochemical processes; the two different treatments were performed for 60 min at pH 3, pH 7, and pH 9. The electrochemical oxidation using boron-doped diamond electrodes processes was carried out using three current density values: 3.11 mA⋅cm −2 , 6.22 mA⋅cm −2 , and 9.33 mA⋅cm −2 , whereas the ozone dose was constantly supplied at 5 ± 0.5 mgL −1 . An optimal degradation condition for the ozonation treatment is at alkaline pH, while the electrochemical treatment works better at acidic pH. The electrochemical process is twice better compared with ozonation

    First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA

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    The search of extragalactic regions with conspicuous presence of Wolf-Rayet (WR) stars outside the Local Group is challenging task due to the difficulties in detecting their faint spectral features. In this exploratory work, we develop a methodology to perform an automated search of WR signatures through a pixel-by-pixel analysis of integral field spectroscopy (IFS) data belonging to the Calar Alto Legacy Integral Field Area survey, CALIFA. This technique allowed us to build the first catalogue of Wolf-Rayet rich regions with spatially-resolved information, allowing to study the properties of these complexes in a 2D context. The detection technique is based on the identification of the blue WR bump (around He II 4686 {\AA}, mainly associated to nitrogen-rich WR stars, WN) and the red WR bump (around C IV 5808 {\AA} and associated to carbon-rich WR stars, WC) using a pixel-by-pixel analysis. We identified 44 WR-rich regions with blue bumps distributed in 25 galaxies of a total of 558. The red WR bump was identified only in 5 of those regions. We found that the majority of the galaxies hosting WR populations in our sample are involved in some kind of interaction process. Half of the host galaxies share some properties with gamma-ray burst (GRB) hosts where WR stars, as potential candidates to being the progenitors of GRBs, are found. We also compared the WR properties derived from the CALIFA data with stellar population synthesis models, and confirm that simple star models are generally not able to reproduce the observations. We conclude that other effects, such as the binary star channel (which could extend the WR phase up to 10 Myr), fast rotation or other physical processes that causes the loss of observed Lyman continuum photons, are very likely affecting the derived WR properties, and hence should be considered when modelling the evolution of massive stars.Comment: 33 pages, accepted for publication in A&

    MEIS1, PREP1, and PBX4 Are Differentially Expressed in Acute Lymphoblastic Leukemia: Association of MEIS1 Expression with Higher Proliferation and Chemotherapy Resistance

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    <p>Abstract</p> <p>Background</p> <p>The Three-amino acid-loop-extension (<it>TALE</it>) superfamily of homeodomain-containing transcription factors have been implicated in normal hematopoiesis and in leukemogenesis and are important survival, differentiation, and apoptosis pathway modulators. In this work, we determined the expression levels of <it>TALE </it>genes in leukemic-derived cell lines, in blood samples of patients with Acute lymphoblastic leukemia (ALL), and in the blood samples of healthy donors.</p> <p>Results</p> <p>Here we show increased expression of <it>MEIS1, MEIS2, </it>and <it>PREP1 </it>genes in leukemia-derived cell lines compared with blood normal cells. High levels of <it>MEIS1 </it>and <it>PREP1</it>, and low levels of <it>PBX4 </it>expression were also founded in samples of patients with ALL. Importantly, silencing of <it>MEIS1 </it>decreases the proliferation of leukemia-derived cells but increases their survival after etoposide treatment. Etoposide-induced apoptosis induces down-regulation of MEIS1 expression or <it>PREP1 </it>up-regulation in chemotherapy-resistant cells.</p> <p>Conclusions</p> <p>Our results indicate that up-regulation of <it>MEIS1 </it>is important for sustaining proliferation of leukemic cells and that down-regulation of <it>MEIS1 </it>or up-regulation of <it>PREP1 </it>and <it>PBX </it>genes could be implicated in the modulation of the cellular response to chemotherapeutic-induced apoptosis.</p
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