82 research outputs found

    Simple Method to Synthesize Functionalized Carbon Nanotubes Employing Cobalt Nitrate and Acetone by Using Spray Pyrolysis Deposition Technique

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    Recently alcohols and ketones have been employed to sensitize CNT by CVD. A study has shown the importance of the chemical nature of those carbon precursors on the characteristics of the CNT (carbon nanotubes) obtained. In the present work we show the influence of the catalyst employed on the synthesis of functionalized multiwall carbon nanotubes (MWCNTs) utilizing acetone as carbon source and cobalt nitrate Co(NO3)2 as catalyst

    An Optical Overview of Poly[μ2-L-alanine-μ3-nitrato-sodium(I)] Crystals

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    Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single crystal has been measured in the 4000–400 cm−1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method

    ACV de la manufactura regional de ladrillos

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    This document presents a Life Cycle Assessment (LCA) study to quantify the environmental cradle-to-gate impact of the manufacture of brick for the construction industry, produced with material of igneous source. Its mineral composition and thermal isolation properties were characterized for use in real estate construction. The LCA results for brick manufacture using this material identified the greatest environmental impact to be associated with material extraction and its proportional cement content. Additionally, this document presents an evaluation of the environmental impact of the manufacturing process by comparing traditional fired clay brick and brick of the material under study. In conclusion, the studied material shows thermal insulation qualities and suitability for the manufacture of bricks with low incorporated energy.Este trabajo presenta un estudio de Análisis de Ciclo de Vida (ACV) para cuantificar los impactos ambientales de la cuna a la puerta de la manufactura de ladrillos para la industria de la construcción, fabricados de un material de origen ígneo. Se caracterizó su composición mineralógica y propiedades de aislamiento térmico para ser usado en la construcción de inmuebles. Los resultados ACV de la fabricación de ladrillos de este material, identificaron la mayor contribución a los impactos ambientales asociados a la extracción del material y la cantidad proporcional de cemento. Adicionalmente, se presenta una evaluación comparativa del impacto ambiental entre la manufactura de un ladrillo tradicional de arcilla cocido y de un ladrillo del material en estudio. En conclusión el material estudiado muestra cualidades de aislamiento térmico y es adecuado para la fabricación de ladrillos con baja energía incorporada

    The cientificWorldJOURNAL Research Article An Optical Overview of Poly[µ 2 -L-alanine-µ 3 -nitrato-sodium(I)] Crystals

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    Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single crystal has been measured in the 4000-400 cm −1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method

    Enhanced optical properties of Cd–Mg-co-doped ZnO nanoparticles induced by low crystal structure distortion

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    The growth of CdxMg0.125-xZn0.875O nanoparticles with yellow-orange luminescence is achieved up to 2.5 at. % Cd via a modified sol–gel process. X-ray diffraction analysis confirmed that all the nanoparticles have the hexagonal wurtzite structure. It is found that Cd doping has a considerable effect on the crystal size, microstrain, band gap, and photoluminescence of the Mg0·125Zn0·875O structure, originating from a preferred crystallographic orientation along the (101) plane of the wurtzite structure. The shift and broadening of the E2(high) mode observed in the Raman spectra due to growth-induced strain corroborates the small distortion observed in the X-ray diffraction data. The optical band gap varies from 3.21 eV to 2.74 eV, being redshifted with increasing Cd concentration (from 0 at. % to 2.5 at. %). The photoluminescence obtained with an excitation wavelength of 325 nm has a broad yellow-orange emission peak at around 640 nm due to transitions related to oxygen vacancies and interstitial oxygen atoms. We located the yellow-orange emission in the chromaticity coordinate diagram in the 2683–2777 K colour temperature region, demonstrating that CdxMg0.125-xZnO0.875 nanoparticles have potential applications in white light-emitting diodes.publishe

    HRTEM characterization of gold nanoparticles produced by wheat biomass

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    In this study, the bio-reduction of Au(III) to Au(0) by wheat biomass and the subsequent production of gold nanoparticles of various shapes and sizes is presented. The dry biomass was ground and sieved in order to assure a uniform particle size and having more area of biomass exposed to the gold. Wheat biomass was exposed to a 0.3mM potassium tetrachloroaurate solution at pH values of 2, 3, 4, 5, and 6 for three and a half hours at room temperature. After that time, the biomass pellets were analyzed using a high resolution transmission electron microscope, JEOL-4000 EX, in order to characterize the gold nanoparticles. The results showed that wheat biomass produced nanostructures of the following morphologies: Fcc tetrahedral (T), decahedral (Dh), hexagonal (He), icosahedral multitwinned (I), irregular shape (Irr), and rod shape nanoparticles. The highest percent of the nanoparticles formed had a particle size ranging from 10-30 nm.Fil: Armendáriz, V.. University of Texas at El Paso; Estados UnidosFil: José Yacamán, Miguel. University of Texas at Austin; Estados UnidosFil: Duarte Moller, A.. University of Texas at El Paso; Estados Unidos. Centro de Investigación en Materiales Avanzados; MéxicoFil: Peralta Videa, J. R.. University of Texas at El Paso; Estados UnidosFil: Troiani, Horacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. University of Texas at Austin; Estados UnidosFil: Herrera, I.. University of Texas at El Paso; Estados UnidosFil: Gardea Torres, J. L.. University of Texas at El Paso; Estados Unido

    CLINICAL CHARACTERISTICS, OUTCOMES AND RISK FACTORS FOR DEATH AMONG CRITICALLY ILL PATIENTS WITH HIV-RELATED ACUTE KIDNEY INJURY

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    SUMMARY Background: The aim of this study is to describe clinical characteristics, outcomes and risk factors for death among patients with HIV-related acute kidney injury (AKI) admitted to an intensive care unit (ICU). Methods: A retrospective study was conducted with HIV-infected AKI patients admitted to the ICU of an infectious diseases hospital in Fortaleza, Brazil. All the patients with confirmed diagnosis of HIV and AKI admitted from January 2004 to December 2011 were included. A comparison between survivors and non-survivors was performed. Risk factors for death were investigated. Results: Among 256 AKI patients admitted to the ICU in the study period, 73 were identified as HIV-infected, with a predominance of male patients (83.6%), and the mean age was 41.2 ± 10.4 years. Non-survivor patients presented higher APACHE II scores (61.4 ± 19 vs. 38.6 ± 18, p = 0.004), used more vasoconstrictors (70.9 vs. 37.5%, p = 0.02) and needed more mechanical ventilation - MV (81.1 vs. 35.3%, p = 0.001). There were 55 deaths (75.3%), most of them (53.4%) due to septic shock. Independent risk factors for mortality were septic shock (OR = 14.2, 95% CI = 2.0-96.9, p = 0.007) and respiratory insufficiency with need of MV (OR = 27.6, 95% CI = 5.0-153.0, p < 0.001). Conclusion: Non-survivor HIV-infected patients with AKI admitted to the ICU presented higher severity APACHE II scores, more respiratory damage and hemodynamic impairment than survivors. Septic shock and respiratory insufficiency were independently associated to death

    Air pollution from traffic and cancer incidence: a Danish cohort study

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    <p>Abstract</p> <p>Background</p> <p>Vehicle engine exhaust includes ultrafine particles with a large surface area and containing absorbed polycyclic aromatic hydrocarbons, transition metals and other substances. Ultrafine particles and soluble chemicals can be transported from the airways to other organs, such as the liver, kidneys, and brain. Our aim was to investigate whether air pollution from traffic is associated with risk for other cancers than lung cancer.</p> <p>Methods</p> <p>We followed up 54,304 participants in the Danish Diet Cancer and Health cohort for 20 selected cancers in the Danish Cancer Registry, from enrolment in 1993-1997 until 2006, and traced their residential addresses from 1971 onwards in the Central Population Registry. We used modeled concentration of nitrogen oxides (NO<sub>x</sub>) and amount of traffic at the residence as indicators of traffic-related air pollution and used Cox models to estimate incidence rate ratios (IRRs) after adjustment for potential confounders.</p> <p>Results</p> <p>NO<sub>x </sub>at the residence was significantly associated with risks for cervical cancer (IRR, 2.45; 95% confidence interval [CI], 1.01;5.93, per 100 μg/m<sup>3 </sup>NO<sub>x</sub>) and brain cancer (IRR, 2.28; 95% CI, 1.25;4.19, per 100 μg/m<sup>3 </sup>NO<sub>x</sub>).</p> <p>Conclusions</p> <p>This hypothesis-generating study indicates that traffic-related air pollution might increase the risks for cervical and brain cancer, which should be tested in future studies.</p

    More stories on Th17 cells

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    For more than two decades, immunologists have been using the so-called Th1/Th2 paradigm to explain most of the phenomena related to adaptive immunity. the Th1/Th2 paradigm implied the existence of two different, mutually regulated, CD4(+) T helper subsets: Th1 cells, driving cell-mediated immune responses involved in tissue damage and fighting infection against intracellular parasites; and Th2 cells that mediate IgE production and are particularly involved in eosinophilic inflammation, allergy and clearance of helminthic infections. A third member of the T helper set, IL-17-producing CD4(+) T cells, now called Th17 cells, was recently described as a distinct lineage that does not share developmental pathways with either Th1 or Th2 cells. the Th17 subset has been linked to autoimmune disorders, being able to produce IL-17, IL-17F and IL-21 among other inflammatory cytokines. Interestingly, it has been reported that there is not only a cross-regulation among Th1, Th2 and Th17 effector cells but there is also a dichotomy in the generation of Th17 and T regulatory cells. Therefore, Treg and Th17 effector cells arise in a mutually exclusive fashion, depending on whether they are activated in the presence of TGF-beta or TGF-beta plus inflammatory cytokines such as IL-6. This review will address the discovery of the Th17 cells, and recent progress on their development and regulation.Crohn's and Colitis Foundation of AmericaNIHLa Jolla Inst Allergy & Immunol, La Jolla, CA 92037 USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilNIH: RO1 AI050265-06Web of Scienc
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