993 resultados para 796.015


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Lipídios como marcadores moleculares (ácidos graxos, esterois e n- alcoois) e COT foram analisados em 48 amostras de sedimento superficial (0-2 cm) em dois períodos (inverno de 2008/2009 e verão de 2009) ao longo de 12 isóbatas em 2 transectos (25 a 3000 m) na principal região de ressurgência da costa sudeste do Brasil, onde a influência do aporte fluvial é mínima. O objetivo foi (i) avaliar as fontes, transporte e regiões de acúmulo da matéria orgânica (MO) (ii) identificar a fração da MO potencialmente disponível para os orgânismos bentônicos. Este estudo faz parte do Projeto Habitats Heterogeneidade Ambiental da Bacia de Campos coordenado pelo CENPES/PETROBRAS. Lipídios derivados da produção primária (0.058 - 3.1 mg gCOT-1) e secundária (0.015 - 2.2 mg gCOT-1) representaram a maior fração da MO sedimentar, enquanto lipídios derivados de fontes alóctonas (0.043 - 0.40 mg gCOT-1) e bactérias (<0.01 - 0.43 mg gCOT-1) foram menos representativos. O padrão de transporte e acúmulo da MO no sedimento depende da associação entre fatores físicos (hidrodinâmicos) e biológicos (resposta a ressurgência), e não é influenciado sazonalmente como observado em dados prévios na mesma região. Verificou-se que regiões restritas da plataforma continental apresentam acúmulo de MO lábil e esse material é exportado para regiões do talude (400 a 1000 m de profundidade), o que representa uma fonte importante de MO biodisponível para a comunidade bentônica desta região.

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Nesta Dissertação, foram realizadas reações de copolimerização de 1,3-butadieno com diferentes alfa-olefinas (1-hexeno, 1-octeno e 1-dodeceno) utilizando-se um sistema catalítico do tipo Ziegler-Natta ternário constituído por versatato de neodímio, hidreto de diisobutilalumínio e cloreto de t-butila. O sistema catalítico também foi avaliado em reações de homopolimerização com cada alfa-olefina. As condições reacionais, tanto da síntese do catalisador como das reações de polimerização, foram mantidas constantes. Foi estudada a influência de diferentes teores de cada alfa-olefina (1, 3, 5, 10, 20 e 30 % em relação ao 1,3-butadieno) sobre a conversão da polimerização, a microestrutura, a massa molar, as propriedades viscosimétricas e a estabilidade térmica dos polímeros obtidos. Foi avaliada, ainda, a influência do tamanho da cadeia da alfa-olefina sobre as características da polimerização. Os polímeros foram caracterizados por espectroscopia na região do infravermelho (FTIR), cromatografia por exclusão de tamanho (SEC), viscosimetria capilar e termogravimetria (TG). A microestrutura dos polímeros, praticamente, não variou com a adição das alfa-olefinas. A massa molar numérica média (Mn) não sofreu alterações significativas, enquanto que a massa molar ponderal média (Mw) apresentou tendência ao aumento, quanto maior foi a incorporação de comonômero. A viscosidade intrínseca não apresentou uma tendência com a adição da alfa-olefina na reação, permanecendo na faixa de 2,015 a 3,557 dL/g. A estabilidade térmica do copolímero mostrou uma tendência a aumentar com a incorporação das alfa-olefinas

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The two lowest T = 3/2 levels in 21Na have been studied in the 19F(3He, n), 20Ne (p,p) and 20Ne (p,p’) reactions, and their excitation energies, spins, parities and widths have been determined. In a separate investigation, branching ratios were measured for the isospin-nonconserving particle decays of the lowest T = 3/2 levels in 17O and 17F to the ground state and first two excited states of 16O, by studying the 15N(3He,n) 17F*(p) 16O and 18O(3He, α)17O*(n) 16O reactions.

The 19F(3He,n) 21Na reaction was studied at incident energies between 4.2 and 5.9 MeV using a pulsed-beam neutron-time-of-flight spectrometer. Two T = 3/2 levels were identified at excitation energies of 8.99 ± 0.05 MeV (J > ½) and 9.22 ± 0.015 MeV (J π = ½+, Γ ˂ 40 keV). The spins and parities were determined by a comparison of the measured angular distributions with the results of DWBA calculations.

These two levels were also obsesrved as isospin-forbidden resonances in the 20Ne(p,p) and 20Ne(p,p’) reactions. Excitation energies were measured and spins, parities, and widths were determined from a single level dispersion theory analysis. The following results were obtained:

Ex = 8.973 ± 0.007 MeV, J π = 5/2 + or 3/2+, Γ ≤ 1.2 keV,

Γpo = 0.1 ± 0.05 keV; Ex = 9.217 ± 0.007 MeV, Jπ = ½ +,

Γ = 2.3 ± 0.5 keV, Γpo = 1.1 ± 0.3 keV.

Isospin assignments were made on the basis of excitation energies, spins, parities, and widths.

Branching ratios for the isospin-nonconserving proton decays of the 11.20 MeV, T = 3/2 level in 17F were measured by the 15N(3He,n) 17 F*(p) 16O reaction to be 0.088 ± 0.016 to the ground state of 16O and 0.22 ± 0.04 to the unresolved 6.05 and 6.13 MeV levels of 16O. Branching ratios for the neutron decays of the analogous T = 3/2 level, at 11.08 MeV in 17O, were measured by the 16O(3He, α)17O*(n)16O reaction to be 0.91 ± 0.15 to the ground state of 16O and 0.05 ± 0.02 to the unresolved 6.05 and 6.13 MeV states. By comparing the ratios of reduced widths for the mirror decays, the form of the isospin impurity in the T = 3/2 levels is shown to depend on Tz.

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The 1.7- and 2.43-MeV levels in 9Be were populated with the reaction 11B(d, α)9Be* by bombarding thin boron on carbon foils with 1.7-MeV deuterons. The alpha particles were analyzed in energy with a surface-barrier counter set at the unique kinematically determined angle and the recoiling 9Be nuclei at 90o were analyzed in rigidity with a magnetic spectrometer, in energy by a surface-barrier counter at the spectrometer focus, and in velocity by the time delay between an alpha and a 9Be count. When a pulse from the spectrometer counter was in the appropriate delayed coincidence with a pulse from the alpha counter, the two pulses were recorded in a two-dimensional pulse height analyzer. Most of the 9Be* decay by particle breakup. Only those that gamma decay are detected by the spectrometer counter. Thus the experiment provides a direct measurement of Γrad/Γ. Analysis of 384 observed events gives Γrad/Γ = (1.16 ± 0.14) X 10-4 for the 2.43-MeV level. Combining this ratio with the value of Γrad = 0.122 ± 0.015 eV found from inelastic electron scattering gives Γ = (1.05 ± 0.18) keV. For the 1.7-MeV level, an upper limit, Γrad/Γ ≤ 2.4 = 10-5, was determined.

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The (He3, n) reactions on B11, N15, O16, and O18 targets have been studied using a pulsed-beam time-of-flight spectrometer. Special emphasis was placed upon the determination of the excitation energies and properties of states with T = 1 (in Ne18), T = 3/2 (in N13 and F17) and T = 2 (in Ne20). The identification of the T = 3/2 and T = 2 levels is based on the structure of these states as revealed by intensities and shapes of angular distributions. The reactions are interpreted in terms of double stripping theory. Angular distributions have been compared with plane and distorted wave stripping theories. Results for the four reactions are summarized below:

1) O16 (He3, n). The reaction has been studied at incident energies up to 13.5 MeV and two previously unreported levels in Ne18 were observed at Ex = 4.55 ± .015 MeV (Γ = 70 ± 30 keV) and Ex = 5.14 ± .018 MeV (Γ = 100 ± 40 keV).

2) B11 (He3, n). The reaction has been studied at incident energies up to 13.5 MeV. Three T = 3/2 levels in N13 have been identified at Ex = 15.068 ± .008 MeV (Γ ˂ 15 keV), Ex = 18.44 ± .04, and Ex 18.98 ± .02 MeV (Γ = 40 ± 20 keV).

3) N15 (He3, n). The reaction has been studied at incident energies up to 11.88 MeV. T = 3/2 levels in F17 have been identified at Ex = 11.195 ± .007 MeV (Γ ˂ 20 keV), Ex = 12.540 ± .010 MeV (Γ ˂ 25 keV), and Ex = 13.095 ± .009 MeV (Γ ˂ 25 keV).

4) O18 (He3, n). The reaction has been studied at incident energies up to 9.0 MeV. The excitation energy of the lowest T = 2 level in Ne20 has been found to be 16.730 ± .006 MeV (Γ ˂ 20 keV).

Angular distributions of the transitions leading to the above higher isospin states are well described by double stripping theory. Analog correspondences are established by comparing the present results with recent studies (t, p) and (He3, p) reactions on the same targets.

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A wavelength division multiplexer (WDM) for 980/1550 nm based on planar curved waveguide coupler (CWC) is proposed. Compared with conventional parallel straight waveguide coupler (SWC), this structure has more flexibility with two variable parameters of bending radius R and minimum edge-to-edge spacing do, which are the two main parameters for the splitting ratio of coupler and decrease the complexity of device design and fabrication. Based on coupled mode theory (CMT) and waveguide theory, R and do of the WDM CWC are designed to be R = 13.28 m and d(0) = 4.39 mu m. The contrast ratio (CR) and insertion loss (IL) for 980 and 1550 nm are CR1 = 24.62 dB, CR2 = 24.56 dB and IL1 = 0.014 dB, IL2 = 0.015 dB, respectively. The 3D beam propagation method (BPM) is used to verify the validity of the design result. The influence of R and d(0) variations on the device performance is analyzed. For CR > 20 dB, the variation ranges of R and d(0) should be within -0.10 to +0.44 m and -0.05 to + 0.02 mu m, respectively. (c) 2006 Elsevier GmbH. All rights reserved.

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El presente informe es uno de los resultados obtenidos en el proyecto de investigación INNOCRE2, Mapa de la Innovación en el Sector Cultural y Creativo de Euskadi, que fue financiado por el Departamento de Industria, Innovación, Comercio y Turismo del Gobierno Vasco (Programa Saiotek, Proyecto S-OA12UN002, 2012-junio 2014). El investigador principal de dicho proyecto fue Javier Echeverría Ezponda (investigador Ikerbasque adscrito al Departamento de Sociología 2 de la Universidad del País Vasco/Euskal Herriko Unibertsitatea). Auxkin Galarraga es profesor del Departamento de Sociología y Trabajo Social de dicha universidad y Liliana Rocca es investigadora y consultora en el área de Psicología Social. El proyecto desarrolló una de las líneas de investigación del grupo de Alto Rendimiento (Nivel A) del sistema universitario vasco “INNOLAB: Innovación, Cambio, Complejidad”, dirigido por Ander Gurrutxaga. A pesar de que la elaboración de este informe ha sido realizado por los firmantes de este artículo, tanto en el diseño metodológico de la encuesta, como en la posterior explotación de los datos también ha participado un amplio grupo de investigadores coordinado por Javier Echeverría y compuesto por orden alfabético por Antón Arana, Marcos Engelken, Andrea Estankona, Ander Gurrutxaga, Zuhar Iruretagoiena, Arantza Lauzirika, Álvaro Luna, Iñaki Martínez de Albeniz, Lucía Merino y Natxo Rodríguez.

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Background: Type 2 diabetes mellitus is associated with a diverse range of pathologies. The aim of the study was to determine the incidence of diabetes-related complications, the prevalence of coexistent chronic conditions and to report multimorbidity in people with type 2 diabetes living in the Basque Country. Methods: Administrative databases, in four cross sections (annually from 2007 to 2011) were consulted to analyse 149,015 individual records from patients aged >= 35 years with type 2 diabetes mellitus. The data observed were: age, sex, diabetes-related complications (annual rates of acute myocardial infarction, major amputations and avoidable hospitalisations), diabetes-related pathologies (prevalence of ischaemic heart disease, renal failure, stroke, heart failure, peripheral neuropathy, foot ulcers and diabetic retinopathy) and other unrelated pathologies (44 diseases). Results: The annual incidence for each condition progressively decreased during the four-year period: acute myocardial infarction (0.47 to 0.40%), major amputations (0.10 to 0.08%), and avoidable hospitalisations (5.85 to 5.5%). The prevalence for diabetes-related chronic pathologies was: ischaemic heart disease (11.5%), renal failure (8.4%), stroke (7.0%), heart failure (4.3%), peripheral neuropathy (1.3%), foot ulcers (2.0%) and diabetic retinopathy (7.2%). The prevalence of multimorbidity was 90.4%. The highest prevalence for other chronic conditions was 73.7% for hypertension, 13.8% for dyspepsia and 12.7% for anxiety. Conclusions: In the type 2 diabetes mellitus population living in the Basque Country, incidence rates of diabetes complications are not as high as in other places. However, they present a high prevalence of diabetes related and unrelated diseases. Multimorbidity is very common in this group, and is a factor to be taken into account to ensure correct clinical management.

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稀土离子掺杂的氧氟玻璃是一种新型上转换发光材料。制备了Tm^3/Yb^3+单掺、共掺的摩尔分数为n(SiO2)-0.30,n(PbF2)-0.50,n=(Al2O3)=0.15,n(AlF3)=(0.049-x),n(TmF3)=y,n(YbF3)=x(x=0,0.001,0.010,0.015,0.020,y=0,0.001)系统氧氟玻璃,研究了其上转换发光特性、分析了其上转换发光机理。研究发现,在970nm抽运光源激发下,Tm^3+单掺时没有可见光上转换发射;而加入Yb^3+后产生了强的蓝光(452n

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Intense Tm3+ blue upconversion emission has been observed in Tm3+-Yb3+ codoped oxyfluoride tellurite glass under excitation with a diode laser at 976 nm. Three emission bands centered at 475, 650 and 796 nm corresponding to the transitions (1)G(4) -> H-3(6), (1)G(4) -> H-3(4) and F-3(4) -> H-3(6), respectively, simultaneously occur. The dependence of upconversion intensities on Tm3+ ions concentration and excitation power are investigated. For fixed Yb2O3 concentrations of 5.0 mol%, the maximum upconversion intensity was obtained with Tm2O3 concentration of about 0.1 mol%. The blue upconversion luminescence lifetimes of the Tm3+ transitions (1)G(4) -> H-3(6) are measured. The results are evaluated by the possible upconversion mechanisms.

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Background: FTY720 (fingolimod, Gilenya(TM)), a structural analog of sphingosine-1-phosphate (S1P), is the first oral drug approved for treatment the relapsing-remitting form of multiple sclerosis (MS), and its efficacy has been related to induced lymphopenia and consequent immunosuppression via modulation of S1P(1) receptors (S1P(1)R). However, due to its lipophilic nature, FTY720 crosses the blood brain barrier (BBB) and could act directly on neural cells. In this study, we investigated the effectiveness of FTY720 as a neuroprotective agent using in vitro and in vivo models of excitotoxic neuronal death and examined if FTY720 exerts a direct action on neurons, or/and an indirect modulation of inflammation-mediated neurodegeneration as a possible mechanism of neuroprotection. Methods: Primary neuronal and organotypic cortical cultures were treated with N-methyl-D-aspartic acid (NMDA) to induce excitotoxic cell death (measured by lactate dehydrogenase (LDH) assay or propidium iodide uptake, respectively). The effects of FTY720 treatment (10, 100 and 1,000 nM) on neuronal survival were examined. As an in vivo model of neuronal death and inflammation, we used intracerebroventricular (icv) administration of kainic acid (KA; 0.5 mu g/2 mu l) in Sprague-Dawley rats. FTY720 was applied icv (1 mu g/2 mu l), together with KA, plus intraperitoneally (ip; 1 mg/kg) 24 h before, and daily, until sacrifice 3 days after icv. Rats were evaluated for neurological score, neuronal loss in CA3 hippocampal region and activation of microglia at the lesion site. In addition, we tested FTY720 as a modulator of microglia responses using microglial cell cultures activated with lipopolysaccharide (LPS) and its effects in stress signalling pathways using western blotting for p38 and JNK1/2 mitogen-activated protein kinases (MAPKs). Results: FTY720 was able to reduce excitotoxic neuronal death in vitro. Moreover, in vivo repeated FTY720 administration attenuated KA-induced neurodegeneration and microgliosis at the CA3 lesion site. Furthermore, FTY720 negatively modulates p38 MAPK in LPS-activated microglia, whereas it had no effect on JNK1/2 activation. Conclusions: These data support a role for FTY720 as a neuroprotective agent against excitotoxin-induced neuronal death and as a negative modulator of neuroinflammation by targeting the p38 MAPK stress signalling pathway in microglia.

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Background: In this study we describe the clinical and molecular characteristics of an outbreak due to carbapenem-resistant Klebsiella pneumoniae (CR-KP) producing CTX-M-15 and OXA-48 carbapenemase. Isogenic strains, carbapenem-susceptible K. pneumoniae (CS-KP) producing CTX-M-15, were also involved in the outbreak. Results: From October 2010 to December 2012 a total of 62 CR-KP and 23 CS-KP were isolated from clinical samples of 42 patients (22 had resistant isolates, 14 had susceptible isolates, and 6 had both CR and CS isolates). All patients had underlying diseases and 17 of them (14 patients with CR-KP and 3 with CS-KP) had received carbapenems previously. The range of carbapenem MICs for total isolates were: imipenem: 2 to >32 mu g/ml vs. <2 mu g/ml; meropenem: 4 to >32 mu g/ml vs. <2 mu g/ml; and ertapenem: 8 to >32 mu g/ml vs. <2 mu g/ml. All the isolates were also resistant to gentamicin, ciprofloxacin, and cotrimoxazole. Both types of isolates shared a common PFGE pattern associated with the multilocus sequence type 101 (ST101). The bla(CTX-M-15) gene was detected in all the isolates, whereas the bla(OXA-48) gene was only detected in CR-KP isolates on a 70 kb plasmid. Conclusions: The clonal spread of K. pneumoniae ST101 expressing the OXA-48 and CTX-M-15 beta-lactamases was the cause of an outbreak of CR-KP infections. CTX-M-15-producing isolates lacking the blaOXA-48 gene coexisted during the outbreak.

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This paper investigates some properties of cyclic fuzzy maps in metric spaces. The convergence of distances as well as that of sequences being generated as iterates defined by a class of contractive cyclic fuzzy mapping to fuzzy best proximity points of (non-necessarily intersecting adjacent subsets) of the cyclic disposal is studied. An extension is given for the case when the images of the points of a class of contractive cyclic fuzzy mappings restricted to a particular subset of the cyclic disposal are allowed to lie either in the same subset or in its next adjacent one.

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El Trabajo de Fin de Grado que he realizado, gira en torno al sector cafetero en la Comunidad Autónoma Vasca. Se trata de un sector en el que operan aproximadamente unas 20 empresas, y la mayoría de ellas son de carácter familiar. No son empresas de gran tamaño, la mayoría son microempresas. Concretamente, el trabajo consiste en la elaboración de unas Cuentas Anuales previsionales de la empresa Cafés Aitona para los años 2.014, 2.015 y 2.016. El trabajo comienza con la contextualización del lector al sector cafetero a modo de introducción, pasando en el siguiente punto a la realización de un diagnóstico de la situación presente de la empresa objeto de estudio en base a la trayectoria pasada, junto con un estudio del entorno y del sector donde opera (empresas de la competencia). En base a la información recabada y en alineación a las decisiones estratégicas adoptadas, realizaré una estimación de las variables básicas que afectarán al futuro inmediato de la empresa. El trabajo finalizará con la propuesta de las Cuentas Anuales Previsionales, en las que se incorporaré los efectos de las estimaciones y decisiones adoptadas. Los objetivos del presente Trabajo de Fin de Grado son demostrar la capacidad de realizar un diagnóstico sobre una realidad empresarial específica, y demostrar la capacidad de emitir juicios y tomar decisiones en base a los datos obtenidos.

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渐变折射率薄膜因为消除了界面而克服了传统的分层介质膜的固有弊端。探讨了一种基于这种渐变膜系的设计方法。从小波理论及渐变折射率增透理论出发,以分层介质高反膜系为参照,给出了采用梳状(Rugate)滤光片设计不同类型颜色滤光片的设计原理,并以目前背投系统中使用的红、绿、蓝颜色滤光片为指标,理论设计出了具有优良光谱特性的红、绿、蓝颜色滤光片;对该设计结果进行了角度敏感性分析、偏振效应分析并与传统的反射膜叠加法得到的分层膜系进行比较,发现通过梳状滤光片理论设计的滤光片较传统的多层膜滤光片具有更小的角度敏感性和较小