18,705 research outputs found

    Effective action in DSR1 quantum field theory

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    We present the one-loop effective action of a quantum scalar field with DSR1 space-time symmetry as a sum over field modes. The effective action has real and imaginary parts and manifest charge conjugation asymmetry, which provides an alternative theoretical setting to the study of the particle-antiparticle asymmetry in nature.Comment: 8 page

    Design, construction and evaluation of a simple pressurized solvent extraction system

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    This work describes the construction and testing of a simple pressurized solvent extraction (PSE) system. A mixture of acetone:water (80:20), 80 ºC and 103.5 bar, was used to extract two herbicides (Diuron and Bromacil) from a sample of polluted soil, followed by identification and quantification by high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). The system was also used to extract soybean oil (70 ºC and 69 bar) using pentane. The extracted oil was weighed and characterized through the fatty acid methyl ester analysis (myristic (< 0.3%), palmitic (16.3%), stearic (2.8%), oleic (24.5%), linoleic (46.3%), linolenic (9.6%), araquidic (0.3%), gadoleic (< 0.3%), and behenic (0.3%) acids) using high-resolution gas chromatography with flame ionization detection (HRGC-FID). PSE results were compared with those obtained using classical procedures: Soxhlet extraction for the soybean oil and solid-liquid extraction followed by solid-phase extraction (SLE-SPE) for the herbicides. The results showed: 21.25 ± 0.36% (m/m) of oil in the soybeans using the PSE system and 21.55 ± 0.65% (m/m) using the soxhlet extraction system; extraction efficiency (recovery) of herbicides Diuron and Bromacil of 88.7 ± 4.5% and 106.6 ± 8.1%, respectively, using the PSE system, and 96.8 ± 1.0% and 94.2 ± 3.9%, respectively, with the SLP-SPE system; limit of detection (LOD) and limit of quantification (LOQ) for Diuron of 0.012 mg kg-1 and 0.040 mg kg-1, respectively; LOD and LOQ for Bromacil of 0.025 mg kg-1 and 0.083 mg kg-1, respectively. The linearity used ranged from 0.04 to 1.50 mg L-1 for Diuron and from 0.08 to 1.50 mg L-1 for Bromacil. In conclusion, using the PSE system, due to high pressure and temperature, it is possible to make efficient, fast extractions with reduced solvent consumption in an inert atmosphere, which prevents sample and analyte decomposition.Este trabalho descreve a construção e teste de um sistema simples de extração pressurizada com solvente (PSE). Uma mistura de acetona:água (80:20), a 80 ºC e 103,5 bar, foi utilizada para extrair dois herbicidas (Diuron e Bromacil) de uma amostra de solo contaminado. Os herbicidas foram identificados e quantificados por cromatografia líquida de alta eficiência acoplada a detector por arranjo de diodos (HPLC-DAD). O sistema também foi utilizado para extrair óleo de soja (70 ºC e 69 bar) empregando pentano como solvente. O óleo extraído foi pesado e caracterizado através da análise dos ésteres metílicos dos ácidos graxos (ácidos mirístico (< 0,3%), palmítico (16,3%), esteárico (2,8%), oléico (24,5%), linoléico (46,3%), linolênico (9,6%), araquídico (0,3%), gadolêico (< 0,3%) e behênico (0,3%)) por cromatografia gasosa de alta eficiência com detecção por ionização em chama (HRGC-FID). Os resultados do sistema PSE foram comparados com os determinados pelos procedimentos tradicionais, ou seja, extração soxhlet para o óleo de soja e extração sólido-líquido seguida da extração em fase sólida (SLE-SPE) para os herbicidas no solo. Com o sistema PSE determinou-se 21,25 ± 0,36% (m/m) de óleo na soja, já com soxhlet 21,55 ± 0,65% (m/m). Para a extração dos herbicidas Diuron e Bromacil, utilizando o sistema PSE, a eficiência (recuperação) foi de 88,7 ± 4,5% e 106,6 ± 8,1%, respectivamente. Já com o sistema SLP-SPE obteve-se 96,8 ± 1,0% e 94,2 ± 3,9%. Os limites de detecção (LOD) e de quantificação (LOQ) para Diuron foram 0,012 mg Kg-1 e 0,040 mg Kg-1, respectivamente. Para Bromacil os LOD e LOQ foram 0,025 mg Kg-1 e 0,083 mg Kg-1. A linearidade utilizada para Diuron ficou na faixa de 0,01 a 1,50 mg L-1 e para Bromacil de 0,02 a 1,50 mg L-1. O sistema PSE, devido à alta pressão e temperatura, possibilita extrações com consumo de solvente reduzido, eficientes, rápida, e uma atmosfera inerte a qual preserva as amostras e os analitos da decomposição.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Immunity, Inflammation and Heart Failure: Their Role on Cardiac Function and Iron Status

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    Aims: Heart failure is a clinical syndrome characterized by subclinical systemic inflammation and immune system activation associated with iron deficiency. No data exist on the various activations of immune-mediated mechanisms of inflammation in heart failure patients with reduced/preserved ejection fraction. We aimed to (1) investigate possible differences in inflammatory parameters and oxidative stress, and (2) detect a different iron status between groups. Materials and Methods: We enrolled 50 consecutive Caucasian outpatients with heart failure. All patients underwent echocardiographic measurements, laboratory determinations, evaluation of iron status and Toll-like receptors, and NF-κB expression in peripheral blood mononuclear cells, as well as pro-inflammatory cytokines. All statistical calculations were made using SPSS for Mac version 21.0. Results: Patients with reduced ejection fraction showed significantly lower hemoglobin levels (12.3 ± 1.4 vs. 13.6 ± 1.4 g/dl), serum iron (61.4 ± 18.3 vs. 93.7 ± 33.7 mcg/dl), transferrin iron binding capacity (20.7 ± 8.4 vs. 31.1 ± 15.6 %), and e-GFR values (78.1 ± 36.1 vs. 118.1 ± 33.9 ml/min/1.73 m2) in comparison to patients with preserved ejection fraction, while unsaturated iron binding capacity (272.6 ± 74.9 vs. 221.7 ± 61.4 mcg/dl), hepcidin (4.61 ± 0.89 vs. 3.28 ± 0.69 ng/ml), and creatinine (1.34 ± 0.55 vs. 1.03 ± 0.25 mg/dl) were significantly higher in the same group. When considering inflammatory parameters, patients with reduced ejection fraction showed significantly higher expression of both Toll-like receptors-2 (1.90 ± 0.97 vs. 1.25 ± 0.76 MFI) and Toll-like receptors-4 (4.54 ± 1.32 vs. 3.38 ± 1.62 MFI), respectively, as well as a significantly higher activity of NF-κB (2.67 ± 0.60 vs. 1.07 ± 0.30). Furthermore, pro-inflammatory cytokines, interleukin-1, and interleukin-6, was significantly higher in patients with reduced ejection fraction, while the protective cytokine interleukin-10 was significantly lower in the same group. Correlational analyses demonstrated a significant and inverse relationship between left ventricular function and inflammatory parameters in patients with reduced ejection fraction, as well as a direct correlation between ferritin and inflammatory parameters. Conclusions: Our data demonstrate a different immune-mediated inflammatory burden in heart failure patients with reduced or preserved ejection fraction, as well as significant differences in iron status. These data contribute to further elucidate pathophysiologic mechanisms leading to cardiac dysfunction

    Efeito das mudanças climáticas para cana-de-açúcar com base no modelo APSIM/Sugarcane.

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    O objetivo deste trabalho foi avaliar a sensibilidade do modelo Agricultural production simulator - sugarcane (APSIM/Sugarcane) (Keating et al. 1998; Thorburn et al., 2005) quanto aos parâmetros climáticos [CO2], temperatura e precipitação, e analisar cenários futuros de mudança climática para a cultura de cana-de-açúcar

    Customer engagement: Growing relevance in marketing research

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    Within marketing research, the number of studies about customer engagement has been growing, emerging mainly after 2005 (Brodie et al., 2011), which reflects the increasing interest of researchers on the topic. The purpose of this study is to provide a systematic literature review to answer to the research question: “What marketing research has been conducted on customer engagement until now and what could be future avenues for research?”info:eu-repo/semantics/publishedVersio

    Energy-momentum Density of Gravitational Waves

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    In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.Comment: LaTeX, 9 pages, 1 table: added reference

    Authenticity in international marketing field: Systematic literature review

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    Purpose:This study aims to usea systematic literature review process to get the state of the art on the concept of authenticity in marketing field. The review question defined is: “What marketing research has been conducted on authenticity in international marketing until now and whatcould be future avenues for research?”.info:eu-repo/semantics/publishedVersio

    Experimental realization of the Yang-Baxter Equation via NMR interferometry

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    The Yang-Baxter equation is an important tool in theoretical physics, with many applications in different domains that span from condensed matter to string theory. Recently, the interest on the equation has increased due to its connection to quantum information processing. It has been shown that the Yang-Baxter equation is closely related to quantum entanglement and quantum computation. Therefore, owing to the broad relevance of this equation, besides theoretical studies, it also became significant to pursue its experimental implementation. Here, we show an experimental realization of the Yang-Baxter equation and verify its validity through a Nuclear Magnetic Resonance (NMR) interferometric setup. Our experiment was performed on a liquid state Iodotrifluoroethylene sample which contains molecules with three qubits. We use Controlled-transfer gates that allow us to build a pseudo-pure state from which we are able to apply a quantum information protocol that implements the Yang-Baxter equation.Comment: 10 pages and 6 figure
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