102 research outputs found
Desenvolvimento de um sistema de gestão e monitoramento da qualidade dos óleos lubrificantes automotivos aplicável ao contexto Angolano
The theme brings us to highlight the importance of analyzing the quality management landscape, the monitoring program and its effects on quality the different types of automotive lubricating oils distributed and marketed in the country. Given that Angola does not produce regular studies on the quality assessment of petroleum products in general and in particular automotive lubricating oils. It is therefore peculiar to analyze quality management since lubricating oils represent a very relevant utility class of petroleum products. Given that in Angola, it has a full market of this product, with several brands and players due to 90% dependence on imports and there have been many drawbacks in its marketing and sales processes. Therefore, this paper presents a proposal for a monitoring program for automotive lubricating oils to ensure that the product has quality. The system is also presented as an example model, which may also be extended to the monitoring and quality management of other classes of lubricating oils and fuels.O tema nos remete a evidenciar a importância de analisar o panorama de gestão de qualidade, no programa de monitoramento e seus efeitos na qualidade os diferentes tipos de óleos lubrificantes automotivos distribuídos e comercializados em Angola. Tendo em conta que Angola não se produz estudos regulares sobre a avaliação da qualidade dos produtos petrolíferos no geral e em particular dos óleos lubrificantes automotivos. Logo é peculiar analisar a gestão da qualidade visto que os óleos lubrificantes representam uma classe de produtos petrolífero de utilidade muito relevante. Atendendo que em Angola, tem um mercado preenchido deste produto, com diversas marcas e players frutos da dependência à 90 % de importações e tem se registado muitos inconvenientes no seu processos de comercialização e vendas. Portanto é apresentado neste trabalho uma proposta de um programa de monitoramento dos óleos lubrificantes automotivos a fim de garantir que o produto tenha qualidade. Apresenta-se também o sistema como modelo de exemplo, que poderá ser estendido também para o monitoramento e gestão da qualidade das outras classes de óleos Lubrificantes e combustíveis
Bulk dynamics for interfacial growth models
We study the influence of the bulk dynamics of a growing cluster of particles
on the properties of its interface. First, we define a {\it general bulk growth
model} by means of a continuum Master equation for the evolution of the bulk
density field. This general model just considers arbitrary addition of
particles (though it can be easily generalized to consider substraction) with
no other physical restriction. The corresponding Langevin equation for this
bulk density field is derived where the influence of the bulk dynamics is
explicitly shown. Finally, when it is assumed a well-defined interface for the
growing cluster, the Langevin equation for the height field of this interface
for some particular bulk dynamics is written. In particular, we obtain the
celebrated Kardar-Parisi-Zhang (KPZ) equation. A Monte Carlo simulation
illustrates the theoretical results.Comment: 6 pages, 2 figure
Evolutionary history, biogeography, and a new species of Sphoeroides (Tetraodontiformes: Tetraodontidae): how the major biogeographic barriers of the Atlantic Ocean shaped the evolution of a pufferfish genus
ABSTRACT: Tetraodontidae is the most speciose family of Tetraodontiformes and is represented by fish popularly known as pufferfishes. They are characterized by modified jaws with four dental plates and the ability to inflate their bodies. Tetraodontids are distributed throughout the world and have a wide range of habitat use. One of its genera, Sphoeroides, shows a biogeographical pattern, with 19 of its 21 species restricted to coastal regions of the Americas. Although represented in large-scale phylogenies, the evolutionary history and biogeography of the genus have not been explored in detail. The present study aims to understand the historical and biogeographic processes that shaped the evolutionary history of Sphoeroides. Including samples from all biogeographic regions of its occurrence, we reconstruct a phylogenetic/biogeographic history hypothesis for the genus. Our results show that Sphoeroides is a paraphyletic group comprising Colomesus; indicate a central role of the biogeographic barriers of the Atlantic Ocean in the diversification of the genus; and identified a cryptic species in Brazilian waters, formally known as S. spengleri, described here through integrative taxonomy. We also propose nomenclatural changes given the position of Colomesus deeply nested within Sphoeroides.info:eu-repo/semantics/publishedVersio
La rehabilitación en Porto como dinamizadora urbana
Porto es una ciudad que ha sufrido un cambio radical en los últimos diez años. Quien la visitara en el pasado la recordará como una ciudad sucia, degradada, e incluso peligrosa. No obstante, una iniciativa municipal surgió para recuperar el centro histórico de la ciudad, de tal manera que el mismo sea dinamizador de la vida urbana. Para comprender este plan, este documento abordará de forma leve la historia de la ciudad, y posteriormente, analizará el elemento más representativo del centro histórico de Porto, la vivienda burguesa. Fruto de este análisis, serán expuestas distintas maneras de actuar sobre el patrimonio, para finalmente, estudiar una serie de actuaciones que ilustrarán estas formas de intervención.<br /
Early neurological deterioration after subarachnoid haemorrhage: risk factors and impact on outcome
Background Early neurological deterioration occurs frequently after subarachnoid haemorrhage (SAH). The impact on hospital course and outcome remains poorly defined.
Methods We identified risk factors for worsening on the Hunt–Hess grading scale within the first 24 h after admission in 609 consecutively admitted aneurysmal SAH patients. Admission risk factors and the impact of early worsening on outcome was evaluated using multivariable analysis adjusting for age, gender, admission clinical grade, admission year and procedure type. Outcome was evaluated at 12 months using the modified Rankin Scale (mRS).
Results 211 patients worsened within the first 24 h of admission (35%). In a multivariate adjusted model, early worsening was associated with older age (OR 1.02, 95% CI 1.001 to 1.03; p=0.04), the presence of intracerebral haematoma on initial CT scan (OR 2.0, 95% CI 1.2 to 3.5; p=0.01) and higher SAH and intraventricular haemorrhage sum scores (OR 1.05, 95% CI 1.03 to 1.08 and 1.1, 95% CI 1.01 to 1.2; p less than 0.001 and 0.03, respectively). Early worsening was associated with more hospital complications and prolonged length of hospital stay and was an independent predictor of death (OR 12.1, 95% CI 5.7 to 26.1; p less than 0.001) and death or moderate to severe disability (mRS 4–6, OR 8.4, 95% CI 4.9 to 14.5; p=0.01) at 1 year.
Conclusions Early worsening after SAH occurs in 35% of patients, is predicted by clot burden and is associated with mortality and poor functional outcome at 1 year
MOTIVADORES DE COMPRA NOS AEROPORTOS BRASILEIROS: UMA TIPOLOGIA PARA O CONSUMIDOR EM AEROPORTOS
In order to enhance their revenue streams, airports have increasingly assumed the role of commercial hubs. However, they differ from traditional retailers because of the atmospheric and psychological issues inherent to the act of traveling. Given the scarcity of studies aimed at understanding the motivators of airport purchases in Brazil, this study seeks to investigate the shopping behavior of Brazilian passengers, researching buying motivations at airports. To this end, 157 Brazilian passengers at Santos Dumont airport (Rio de Janeiro) were invited to participate in a survey. The survey instrument was developed based on the variables and constructs suggested by Geuens, Vantomme e Brengman (2004).The results revealed four dimensions of buying motivation: two of them linked to the characteristics of an airport – “Atmospheric” and “Airport Related” - and two others linked to traditional buying behavior – “Social” and “Functional”. Based on the revealed motivational dimensions, the Brazilian passengers were classified in four different groups: Interactive Consumer, Self-centered Consumer, Traditional Consumer and Apathetic/Indifferent Consumer.Con el fin de mejorar sus flujos de ingresos, los aeropuertos asumen cada vez más el papel de centros comerciales. Sin embargo, se diferencian de los minoristas tradicionales debido a las particularidades atmosféricas y psicológicas inherentes al acto de viajar. Dada la escasez de estudios dirigidos a comprender las motivaciones de compra en aeropuertos de Brasil, este artículo pretende averiguar el comportamiento comercial de los pasajeros brasileños, investigando las motivaciones de los compradores en los aeropuertos. Con este fin, 157 pasajeros brasileños en el aeropuerto Santos Dumont (Río de Janeiro) fueron invitados a participar en un survey. El instrumento de la encuesta fue desarrollado en base a las variables sugeridas por Geuens, Vantomme e Brengman (2004). Los resultados revelaron cuatro dimensiones de la motivación del comprador: dos de ellas vinculadas a las características de un aeropuerto - "Atmósfera" y "Relacionados con los Aeropuertos" - y otras dos relacionadas con el comportamiento de compra tradicional: "Social" y "Funcional". Con base en las dimensiones de motivación reveladas, los pasajeros de Brasil fueron clasificados en cuatro grupos distintos de consumidores: los consumidores interactivos, los consumidores centrados en sí mismos, los consumidores tradicionales y los consumidores apáticos/indiferentes.De forma a aumentar as suas fontes de receita, os aeroportos assumem cada vez mais um papel de polo comercial. No entanto, eles se diferenciam do varejo tradicional pelas questões psicológicas e atmosféricas inerentes ao ato de viajar. Perante a escassez de estudos no Brasil voltados para o entendimento dos motivadores de compra nos aeroportos brasileiros, este estudo se propõe a investigar o comportamento de compras de passageiros brasileiros, pesquisando motivações de compra em aeroportos. Para tanto, 157 passageiros brasileiros do Aeroporto Santos Dumont (Rio de Janeiro) foram convidados a participar de uma survey elaborada com base nas variáveis e constructos sugeridos por Geuens, Vantomme e Brengman (2004). Os resultados revelaram quatro dimensões de motivação de compra: duas delas ligadas às características de um aeroporto – Atmosféricas e Relacionadas ao Aeroporto – e outras duas comuns ao comportamento tradicional de compra – Social e Funcional. Baseado nas dimensões reveladas, os passageiros brasileiros foram classificados em quatro tipos distintos de consumidores: Consumidor Interativo, Consumidor Egocêntrico, Consumidor Tradicional e Consumidor Apático/Indiferente
A systematic review of the evidence for single stage and two stage revision of infected knee replacement
BACKGROUND:
Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates.
METHODS:
A systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded.
RESULTS:
63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies.
CONCLUSIONS:
Evidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority
Systemic glucose variability predicts cerebral metabolic distress and mortality after subarachnoid hemorrhage: a retrospective observational study
Introduction: Cerebral glucose metabolism and energy production are affected by serum glucose levels. Systemic glucose variability has been shown to be associated with poor outcome in critically ill patients. The objective of this study was to assess whether glucose variability is associated with cerebral metabolic distress and outcome after subarachnoid hemorrhage. Methods: A total of 28 consecutive comatose patients with subarachnoid hemorrhage, who underwent cerebral microdialysis and intracranial pressure monitoring, were studied. Metabolic distress was defined as lactate/pyruvate ratio (LPR) >40. The relationship between daily glucose variability, the development of cerebral metabolic distress and hospital outcome was analyzed using a multivariable general linear model with a logistic link function for dichotomized outcomes. Results: Daily serum glucose variability was expressed as the standard deviation (SD) of all serum glucose measurements. General linear models were used to relate this predictor variable to cerebral metabolic distress and mortality at hospital discharge. A total of 3,139 neuromonitoring hours and 181 days were analyzed. After adjustment for Glasgow Coma Scale (GCS) scores and brain glucose, SD was independently associated with higher risk of cerebral metabolic distress (adjusted odds ratio = 1.5 (1.1 to 2.1), P = 0.02). Increased variability was also independently associated with in hospital mortality after adjusting for age, Hunt Hess, daily GCS and symptomatic vasospasm (P = 0.03). Conclusions: Increased systemic glucose variability is associated with cerebral metabolic distress and increased hospital mortality. Therapeutic approaches that reduce glucose variability may impact on brain metabolism and outcome after subarachnoid hemorrhage
Effects of the neurological wake-up test on clinical examination, intracranial pressure, brain metabolism and brain tissue oxygenation in severely brain-injured patients
Introduction
Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients. Little is known about the benefit of IS in acutely brain-injured patients.
Methods
This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center. Twenty consecutive severely brain-injured patients with multimodal neuromonitoring were analyzed for levels of brain lactate, pyruvate and glucose, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and brain tissue oxygen tension (PbtO2) during IS trials.
Results
Of the 82 trial days, 54 IS-trials were performed as interruption of sedation and analgesics were not considered safe on 28 days (34%). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by a median of three (two to four) points. Detection of a new neurologic deficit occurred in one trial (2%), and in one-third of IS-trials the trial had to be stopped due to an ICP-crisis (> 20 mmHg), agitation or systemic desaturation. In IS-trials that had to be aborted, a significant increase in ICP and decrease in PbtO2 (P < 0.05), including 67% with critical values of PbtO2 < 20 mmHg, a tendency to brain metabolic distress (P < 0.07) was observed.
Conclusions
Interruption of sedation revealed new relevant clinical information in only one trial and a large number of trials could not be performed or had to be stopped due to safety issues. Weighing pros and cons of IS-trials in patients with acute brain injury seems important as related side effects may overcome the clinical benefit
Mining Virulence Genes Using Metagenomics
When a bacterial genome is compared to the metagenome of an environment it inhabits, most genes recruit at high sequence identity. In free-living bacteria (for instance marine bacteria compared against the ocean metagenome) certain genomic regions are totally absent in recruitment plots, representing therefore genes unique to individual bacterial isolates. We show that these Metagenomic Islands (MIs) are also visible in bacteria living in human hosts when their genomes are compared to sequences from the human microbiome, despite the compartmentalized structure of human-related environments such as the gut. From an applied point of view, MIs of human pathogens (e.g. those identified in enterohaemorragic Escherichia coli against the gut metagenome or in pathogenic Neisseria meningitidis against the oral metagenome) include virulence genes that appear to be absent in related strains or species present in the microbiome of healthy individuals. We propose that this strategy (i.e. recruitment analysis of pathogenic bacteria against the metagenome of healthy subjects) can be used to detect pathogenicity regions in species where the genes involved in virulence are poorly characterized. Using this approach, we detect well-known pathogenicity islands and identify new potential virulence genes in several human pathogens
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