Characterization of fluid flow in a microchannel with a flow disturbing step

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The flow around a flow-disturbing step in a rectangular microchannel is studied by measuring the wall shear rate along the channel, using the electrodiffusion technique and by determining the velocity field using the -PIV method. A parametric study based on the Design of Experiments (DOE) and the Response Surface Methodology (RSM) was then performed, and the effect of key design parameters on the flow characteristics was numerically investigated using CFD simulations. The computational results are in excellent agreement with the corresponding experimental ones. The CFD simulations cover both the laminar and the turbulent flow regime. It was revealed that in both flow regimes the step height has a major influence on the recirculation length. However, the Reynolds number (Re) value affects the recirculation length only in the laminar region, while the step length seems to have no significant effect compared to the Re and the step height. Finally, new correlations are proposed predicting the length of the bottom recirculation zone with reasonable accuracy and can be used as rough guidelines for the design of microdevices

Influential factors on the levels of cation exchange capacity in sediment at Langat river.

An exploratory study was carried out at 22 sampling stations along the Langat River, Selangor in order to investigate on the vitality of cation exchange capacity (CEC) in sediment (0–5 cm). Parameters such as pH, Eh, salinity, and electrical conductivity (EC) were determined. The CEC in sediment has been calculated by the determination of Ca2+, Na+, Mg2+, and K+ using the flame atomic absorption spectrophotometer, while the organic matter content in sediment was ascertained using the loss on ignition method. The characteristic of the sediment shows that pH (3.09–7.46), salinity (0.02–10.71 ppt), EC (3.39–517 μS/cm) and Eh (−16.20–253.10 mV) were substantially high in variation. This study also revealed that exchangeable Ca2+ and Mg2+ were controlled by organic matter contents, while exchangeable Na+ and K+ were influenced by salinity. Salinity was observed to play a major part in controlling all the exchangeable cations, as it gives strong significant correlations with Na+, K+, Mg2+, CEC, and organic matter at p < 0.01. The presence of seawater, clay mineralogy, and organic matter proves that it does play an important role in determining the CEC and soon relates to the pollution magnitude in the sediment

CONHECIMENTOS E PRÁTICAS DOS CIRURGIÕES DENTISTAS DA CIDADE DE ANÁPOLIS NO TRATAMENTO DE PACIENTES QUE FIZERAM OU FAZEM USO DE BISFOSFONATOS

Pacientes  com  câncer  avançado  frequentemente  apresentam complicações  ósseas  que  podem  comprometer  consideravelmente  sua qualidade  de  vida.  Com  isso  os  bisfosfonatos  tornaram-se  a  principal  arma terapêutica  na  prevenção  de  complicações  ósseas  de  doença  maligna,  com eficácia  na  normalização  do  cálcio  sérico,  além  de  aliviar  a  dor  óssea.  Em contra  partida,  houve  um  aumento  de  osteonecrose  nos  maxilares  durante  o tratamento  odontológico  cirúrgico,  como  por  exemplo,  extrações  dentárias  e implantes  dentários

Modulation of the peripheral blood transcriptome by the ingestion of probiotic yoghurt and acidified milk in healthy, young men

The metabolic health benefits of fermented milks have already been investigated using clinical biomarkers but the development of transcriptomic analytics in blood offers an alternative approach that may help to sensitively characterise such effects. We aimed to assess the effects of probiotic yoghurt intake, compared to non-fermented, acidified milk intake, on clinical biomarkers and gene expression in peripheral blood. To this end, a randomised, crossover study was conducted in fourteen healthy, young men to test the two dairy products. For a subset of seven subjects, RNA sequencing was used to measure gene expression in blood collected during postprandial tests and after two weeks daily intake. We found that the postprandial response in insulin was different for probiotic yoghurt as compared to that of acidified milk. Moreover changes in several clinical biomarkers were associated with changes in the expression of genes representing six metabolic genesets. Assessment of the postprandial effects of each dairy product on gene expression by geneset enrichment analysis revealed significant, similar modulation of inflammatory and glycolytic genes after both probiotic yoghurt and acidified milk intake, although distinct kinetic characteristics of the modulation differentiated the dairy products. The aryl hydrocarbon receptor was a major contributor to the down-regulation of the inflammatory genesets and was also positively associated with changes in circulating insulin at 2h after yoghurt intake (p = 0.05). Daily intake of the dairy products showed little effect on the fasting blood transcriptome. Probiotic yoghurt and acidified milk appear to affect similar gene pathways during the postprandial phase but differences in the timing and the extent of this modulation may lead to different physiological consequences. The functional relevance of these differences in gene expression is supported by their associations with circulating biomarkers

Ocorrência de casos de leishmaniose tegumentar americana: uma análise multivariada dos circuitos espaciais de produção, Minas Gerais, Brasil, 2007 a 2011

O objetivo deste estudo foi explicar a associação dos fatores socioambientais e dos grandes usos da terra com a ocorrência de casos de leishmaniose tegumentar americana (LTA) nos circuitos espaciais de produção, no Estado de Minas Gerais, Brasil. Trata-se de um estudo ecológico do tipo analítico, baseado em dados secundários de casos de LTA dividido por triênio, no período entre 2007 a 2011, cujas unidades de análise foram os municípios pertencentes aos circuitos espaciais. Duas etapas distintas foram realizadas, sendo a elaboração de mapas temáticos com a identificação dos circuitos a primeira, e na segunda etapa um novo indicador casos de LTA por densidade demográfica foi associado com indicadores socioambientais e dos grandes usos da terra submetidos à análise multivariada de componentes principais (ACP). Para o período avaliado, identificou-se três circuitos distribuídos nas mesorregiões Norte de Minas Gerais, Vale do Rio Doce e Região Metropolitana de Belo Horizonte. Houve forte associação dos casos de LTA por densidade demográfica com lavoura temporária, pastagem natural, floresta natural, terras inaproveitáveis e população rural, e uma fraca associação com pastagem plantada. A associação de casos com variáveis dos grandes usos da terra em diferentes perfis agropecuários demonstra o caráter ocupacional da LTA, associado principalmente com trabalhadores da zona rural. A associação da doença com as variáveis ambientais e deficiência das condições de saneamento básico também demonstram relevância no perfil de transmissão nos circuitos espaciais de produção em Minas Gerais