1,081 research outputs found

    Highly improved sensitivity of TS-FF-AAS for Cd(II) determination at ng L-1 levels using a simple flow injection minicolumn preconcentration system with multiwall carbon nanotubes

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    A new method for cadmium determination at ng L-1 levels is described. The method is based on the on-line coupling of a flow preconcentration system using multiwall carbon nanotubes (MWCNT) as sorbent with TS-FF-AAS determination. Cadmium preconcentration was at pH 4.9 onto an MWCNT minicolumn (30 mg) for 2 min at a 5.0 mL min(-1) flow rate. The elution step is performed by using 0.5 mol L-1 HNO3 and the cadmium desorbed is directly pumped to a TS-FF-AAS. All experimental parameters that play important roles in system performance were evaluated and optimized by means of fractional factorial designs and response surface methodology. The excellent characteristics of MWCNT as sorbent, mainly owing to its high surface area, make it possible to obtain a preconcentration factor of 51-fold, thus improving the detection and quanti. cation limits in TS-FF-AAS, 11.4 and 38.1 ng L-1, respectively. When the flow preconcentration system, FI-TS-FF-AAS, was compared with FAAS alone, an increase in the sensitivity of 640-fold was obtained. The calibration graph was linear with a correlation coefficent higher than 0.999 from 38.1 to 1250 ng L-1. Repeatability of the measurements (n = 10), assessed as relative standard deviation (RSD), was found to be 6.5 and 2.1% for cadmium concentrations of 100 and 1000 ng L-1, respectively. Important parameters to characterize the flow preconcentration system were also evaluated, the consumption index being 0.196 mL, the concentration efficiency 25.5 min(-1) and the sample throughput 20 samples per hour. In order to demonstrate the accuracy of the system, addition and recovery studies in water samples (mineral water, tap water and river water) and cigarette samples were carried out. Moreover, for the same purpose, cadmium was determined in certified biological materials (Bovine Liver and Rye Grass), giving an average result in close agreement with the certified value.21111305131

    In the Murine and Bovine Maternal Mammary Gland Signal Transducer and Activator of Transcription 3 is Activated in Clusters of Epithelial Cells around the Day of Birth

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    Signal transducers and activators of transcription (STAT) proteins regulate mammary development. Here we investigate the expression of phosphorylated STAT3 (pSTAT3) in the mouse and cow around the day of birth. We present localised colocation analysis, applicable to other mammary studies requiring identification of spatially congregated events. We demonstrate that pSTAT3-positive events are multifocally clustered in a non-random and statistically significant fashion. Arginase-1 expressing cells, consistent with macrophages, exhibit distinct clustering within the periparturient mammary gland. These findings represent a new facet of mammary STAT3 biology, and point to the presence of mammary sub-microenvironments.</p

    Nursing in the hospital accreditation process: practice and implications in the work quotidian

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    The aim of this study was to investigate the role and influence of nursing in the hospital accreditation process. It is a qualitative study, conducted in a private hospital of Belo Horizonte. The study subjects were nine nurses and 15 nursing technicians. Data collection was through semi-structured interviews, which were subjected to content analysis. The results showed that the role of the nursing team in the accreditation involves care, administrative, educational and research issues. The study subjects presented different perceptions regarding the influence of the accreditation process in their work. The positive aspects of personal growth and valorization of the curriculum were highlighted as well as negative aspects such as stress and little professional valorization. Therefore, it is necessary that the professionals understand the logic of the process and act with a view to the interdisciplinarity and overcoming the fragmentation of care, thus achieving integral healthcare and the quality of care desired.Este estudio investigó el papel y la influencia de la enfermería en el proceso de acreditación de hospitales. Se trata de un estudio cualitativo realizado en un hospital en Belo Horizonte. Los sujetos del estudio fueron 09 enfermeras y 15 técnicos de enfermería. Los datos fueron recolectados a través de entrevistas semiestructuradas, las que fueron sometidas a análisis de contenido. Los resultados mostraron que la actuación de la enfermería en el proceso de acreditación implica cuestiones relacionadas con la atención, administración, educación e investigación. Los profesionales tenían percepciones diferentes acerca de la influencia del proceso de acreditación en su trabajo. Se destacaron aspectos positivos como el crecimiento personal y el desarrollo del currículo; los negativos fueron estrés y poco desarrollo profesional. Por lo anterior es necesario que los profesionales entiendan la lógica del proceso y actúen con una finalidad interdisciplinaria superando la fragmentación en el cuidado, logrando así la atención integral y la calidad de la atención.Os objetivos neste estudo foram conhecer a atuação e as influências da enfermagem no processo de acreditação hospitalar. Trata-se de pesquisa qualitativa, realizada em um hospital privado de Belo Horizonte, MG. Esta pesquisa ficou composta por nove enfermeiros e quinze técnicos de enfermagem. Os dados foram coletados por meio de entrevistas com roteiro semiestruturado, submetidas à análise de conteúdo. Os resultados mostraram que a atuação da enfermagem na acreditação envolve questões assistenciais, administrativas, educativas e de pesquisa. Os sujeitos da pesquisa apresentaram percepções diversas sobre a influência do processo de acreditação no seu trabalho. Foram destacados aspectos positivos como crescimento pessoal e valorização do currículo e aspectos negativos como estresse e pouca valorização profissional. Assim, é necessário que os profissionais entendam a lógica do processo, atuem com vistas à interdisciplinaridade e superação da fragmentação da assistência, alcançando assim o cuidado integral e a qualidade assistencial desejada

    Development of carpels and ovules in Dialypetalanthus fuscescens Kuhlm. (Rubiaceae): an enigmatic taxon

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    ABSTRACT Dialypetalanthus is a monospecific genus that occurs in the Amazon Basin of Brazil, Bolivia and Peru and occupies a controversial position among the Rubiaceae. We continue this taxonomic discussion with the overall aim of clarifying the systematic position of D. fuscescens within the Rubiaceae. To accomplish this, we analyzed the ontogeny of its gynoecium, in particular the floral meristem, as well as the development of the carpels and cauline placentation. Gynosporogenesis and the differentiation of the carpellary septa and ovules were also described. Dialypetalanthus fuscescens was classified according to evolutionary diagrams found in the literature. The following characteristics were observed in D. fuscescens: 1) permanence of the floral meristem in the central basal part of the early flower bud; 2) dual origin of carpellary septum; 3) trizonate ovular primordia with only one fertile gynospore per ovule; and 4) cellular proliferation in the chalazal region. Embryological results confirm the classification of D. fuscescens in the subfamily Ixoroideae. These results are distinct from any others previously proposed in the evolutionary diagram. Therefore, we conclude that this study has presented evidence strongly suggesting that Dialypetalanthus possesses new morphological-type of ovule we refer to as the Dialypetalanthus-type

    FATAL OUTCOME OF INFECTION BY DENGUE 4 IN A PATIENT WITH THROMBOCYTOPENIC PURPURA AS A COMORBID CONDITION IN BRAZIL

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    Dengue is currently a major public-health problem. Dengue virus (DENV) is classified into four distinct serotypes, DENV 1-4. After 28 years of absence, DENV-4 was again detected in Brazil in 2010 in Roraima State, and one year later, the virus was identified in the northern Brazilian states of Amazonas and Pará, followed by Rio de Janeiro and São Paulo. In Minas Gerais, the first confirmed case of DENV-4 occurred in the municipality of Frutal in 2011 and has now been isolated from a growing number of patients. Although DENV-2 is associated with the highest risk of severe forms of the disease and death due to the infection, DENV-4 has also been associated with severe forms of the disease and an increasing risk of hemorrhagic manifestations. Herein, the first fatal case of confirmed DENV-4 in Brazil is reported. The patient was an 11-year-old girl from the municipality of Montes Claros in northern Minas Gerais State, Brazil. She had idiopathic thrombocytopenic purpura as a comorbid condition and presented with a fulminant course of infection, leading to death due to hemorrhagic complications. Diagnosis was confirmed by detection of Dengue-specific antibodies using IgM capture enzyme-linked immunosorbent assay and semi-nested RT-PCR. Primary care physicians and other health-care providers should bear in mind that DENV-4 can also result in severe forms of the disease and lead to hemorrhagic complications and death, mainly when dengue infection is associated with coexisting conditions

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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