137 research outputs found

    Backscatter Transponder Based on Frequency Selective Surface for FMCW Radar Applications

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    This paper describes an actively-controlled frequency selective surface (FSS) to implement a backscatter transponder. The FSS is composed by dipoles loaded with switching PIN diodes. The transponder exploits the change in the radar cross section (RCS) of the FSS with the bias of the diodes to modulate the backscattered response of the tag to the FMCW radar. The basic operation theory of the system is explained here. An experimental setup based on a commercial X-band FMCW radar working as a reader is proposed to measure the transponders. The transponder response can be distinguished from the interference of non-modulated clutter, modulating the transponder’s RCS. Some FSS with different number of dipoles are studied, as a proof of concept. Experimental results at several distances are provided

    Trace-metaldynamics in response of increase CO<sub>2</sub> and iron availability in a coastal mesocosm experiment

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    A mesocosm experiment was performed in the Raunefjord (Norway) to study changes in dissolved Cu (dCu) and Fe (dFe), and in the elemental composition of particles during an Emiliania huxleyi dominated bloom. The CO2 treatments consisted of present (LC; 390 ppmV) and predicted levels (HC; 900 ppmV) and iron conditions were created with the addition of the siderophore desferoxamine B (DFB). Our results showed the DFB addition enhanced the solubility of Fe in this fjord environment. Initially, dFe was comparable among treatments but after the addition, the HC and/or +DFB treatments presented higher levels and finally, the only ones maintaining high dFe were the +DFB treatments. Unlike dCu presented indistinguishable levels in all mesocosms over time. Particulate metals were normalised to P and Al to evaluate the relative influence of biotic and abiotic sources. The Fe:P ratios decreased with time and compared to published phytoplankton ratios suggest Fe storage. On the other hand, Fe:Al ratios were relatively closer to the crustal ratios suggesting that the abiotic source was more important for this metal. Trends for other metals will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    AplicaciĂłn del Mantenimiento Preventivo Para la Mejora de la Productividad en el Taller Postventa, Empresa Modasa

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    Este trabajo denominado “Aplicación del mantenimiento preventivo para mejorar la productividad en el área de post venta en la empresa MODASA 2018, tuvo como objetivo implantar la propuesta. Fue cuasi experimental. Con muestra del control del mantenimiento con datos de setiembre 2017 a febrero 2018. Se encontró que, con la aplicación, la productividad en promedio aumentó en 32%, la eficacia en 18.16% y la Eficiencia en 18.2%. Conclusión: Se considera fundamentar estudiar los factores que destacan el mantenimiento preventivo en las industrias

    The effects of ocean acidification and siderophore additions on trace-metal dynamics during an Emiliania Huxleyi- dominated bloom in a coastal mesocosm experiment

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    The combined impacts of high CO2 and changes in trace metal availability on plankton remain largely unknown. A 22 days mesocosm experiment was carried out in the Raunefjord, off Bergen, Norway (June 2012) to investigate the interactive effects of increased CO2 and changes in iron availability in the pelagic community. Twelve mesocosms covered by PAR and UVR transparent lids were used. The CO2 treatments consisted of present (LC; 390 ppmV) and predicted levels for year 2100 (HC; 900 ppmV). On day 7, half of the mesocoms were amended with the siderophore desferoxamine B (DFB) at 70 nM (final concentration). We studied changes in dissolved Cu (dCu) and Fe (dFe), and in the elemental composition of particles. Dissolved Fe and dCu were measured by chemiluminescence flow injection analysis, while particulate metals were determined by high-resolution inductively coupled mass spectrometry. The metals were normalised to P and Al to evaluate the relative influence of biotic and abiotic sources. Samples were taken throughout a bloom of the coccolithophore E. huxleyi. Further details will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Yerba Mate Modulates Tumor Cells Functions Involved in Metastasis in Breast Cancer Models

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    Breast cancer (BC) is the most frequent cancer in women and tumor metastasis is a major cause of cancer-related deaths. Our aim was to evaluate anti-metastatic properties of yerba mate extract (YMe) in BC models. 4T1, F3II, MCF-7, and MDA-MB231 cell lines were used to perform in vitro assays. The F3II syngeneic mammary carcinoma model in BALB/c mice was used to evaluate tumor progression, BC metastasis and survival. Cells were inoculated subcutaneously into the flank for the heterotopic model and into the mammary fat pad for the orthotopic model. YMe was administered p.o. in a dose of 1.6 g/kg/day. In vitro YMe inhibited cell proliferation and reduced tumor cell adhesion, migration and invasion. These biological effects were cell-line dependent. In vivo YMe reduced tumor metastasis and increased mice survival in both models. Our preclinical results suggest that YMe could modulate tumor progression and metastasis in BC models.Fil: Garcia Lazaro, Rocio Soledad. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Caligiuri, Lorena Gisel. Universidad Nacional de Quilmes; ArgentinaFil: Lorenzo Pérez, Norailys. Universidad Nacional de Quilmes; ArgentinaFil: Lamdan, Humberto. Universidad Nacional de Quilmes; ArgentinaFil: Alonso, Daniel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Anti-proliferative effects of a blueberry extract on a panel of tumor cell lines of different origin

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    Background: Blueberries are among the fruits with the highest antioxidant activity and have been recognized by their health promoting properties. Aim:In vitro study of the anti-proliferative effects of a blueberry extract on a panel of cancer cells from different origin. Materials and Methods: A blueberry extract was produced using ethanol as extracting solvent. The anti-proliferative activity of the extract was evaluated against seven tumor cell lines. The properties of blueberry extract to decrease cell adhesion and migration were also investigated. Results: Blueberry extract showed a dose-dependent inhibitory effect on cell proliferation for all cell lines. Non-cytotoxic concentrations of the extract decreased cell adhesion in five of seven cell lines studied and inhibited the migration of MDA-MB-231 and PC-3 tumor cells. Conclusion: This work provides additional evidence regarding the ability of blueberry extract to inhibit the growth and decrease cell adhesion and migration of different cancer cell lines in vitro. Key Words: anthocyanins, anti-proliferative, blueberry extract, cancer, polyphenols.Fil: Lamdan Ordas, Humberto. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Garcia Lazaro, Rocio Soledad. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lorenzo Pérez, Norailys. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Caligiuri, Lorena Gisel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Estudio de la yerba mate (Ilex paraguariensis) en el crecimiento y la progresiĂłn tumoral

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    Existen evidencias en la bibliografía que muestran la potencialidad antitumoral de la Yerba Mate en modelos in vitro aislados como proliferación, crecimiento o invasión. Ninguno de estos trabajos evalúa en modelos conjuntos in vitro e in vivo la administración crónica de la Yerba Mate mediante extractos sobre la progresión tumoral en modelos integrales. El laboratorio de Oncología Molecular, específicamente, uno de sus proyectos denominado «Fitomedicina y cáncer», ha estudiado en profundidad el rol de la Yerba Mate en modelos de progresión tumoral. Para ello, ha utilizado un extracto soluble de Yerba Mate secado por el método de secado spray. La identificación fisicoquímica indicó que este extracto contiene una mezcla compleja de fitoquímicos activos

    Mutagenic effects of sodium azide on pineapple micropropagant growth and biochemical profile within temporary immersion bioreactors

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    Sodium azide (NaN3) is widely used to induce mutagenesis within in vitro plant systems. However, since this mutagenesis is undirected, its unintended effects demand characterization. This study investigated the mutagenic effects of sodium azide (0-0.45 mM) on selected growth (shoot multiplication rate and shoot cluster fresh weight) and biochemical (aldehydes, chlorophylls, carotenoids and phenolics) parameters in pineapple micropropagants within temporary immersion bioreactors (TIBs). The content of soluble phenolics in the culture medium was also evaluated. Irrespective of the concentration NaN3 decreased shoot multiplication rate (by 87% relative to the control at 0.45 mM) and fresh weight (by 66% relative to the control at 0.45 mM). Levels of chlorophyll a and b, and soluble phenolics in the culture medium were also negatively correlated with NaN3 concentration. Interestingly, NaN3 application increased shoot carotenoid and soluble phenolic levels but had no significant effect on a range of established plant stress biomarkers: cell wall-linked phenolic levels, malondialdehyde and other aldehydes. Given that 0.19 mM NaN3 decreased shoot multiplication rate by 50% and resulted in propagants that displayed no morphologically abnormalities, increased levels of photoprotective pigments (relative to the control) and no significant increase in lipid peroxidation products, the mutagen can be used at this concentration to induce pineapple mutagenesis in TIB based studies aimed at producing agriculturally-useful mutants
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