The development of laser speckle or particle image displacement velocimetry. Part 1: The role of photographic parameters

One of the difficult problems in experimental fluid dynamics remains the determination of the vorticity field in fluid flows. Recently, a novel velocity measurement technique, commonly known as Laser Speckle or Particle Image Displacement Velocimetry became available. This technique permits the simultaneous visualization of the 2 dimensional streamline pattern in unsteady flows and the quantification of the velocity field. The main advantage of this new technique is that the whole 2 dimensional velocity field can be recorded with great accuracy and spatial resolution, from which the instantaneous vorticity field can be easily obtained. A apparatus used for taking particle displacement images is described. Local coherent illumination by the probe laser beam yielded Young's fringes of good quality at almost every location of the flow field. These fringes were analyzed and the velocity and vorticity fields were derived. Several conclusions drawn are discussed

A differential diagnosis of inherited endocrine tumors and their tumor counterparts

Inherited endocrine tumors have been increasingly recognized in clinical practice, although some difficulties still exist in differentiating these conditions from their sporadic endocrine tumor counterparts. Here, we list the 12 main topics that could add helpful information and clues for performing an early differential diagnosis to distinguish between these conditions. The early diagnosis of patients with inherited endocrine tumors may be performed either clinically or by mutation analysis in at-risk individuals. Early detection usually has a large impact in tumor management, allowing preventive clinical or surgical therapy in most cases. Advice for the clinical and surgical management of inherited endocrine tumors is also discussed. In addition, recent clinical and genetic advances for 17 different forms of inherited endocrine tumors are briefly reviewed

A Multiplex PCR Assay for Detection of Salmonella sp., Listeria monocytogenes, Campylobacter sp., Staphylococcus aureus and Escherichia coli

Contaminated food and water are usual vehicles for bacterial pathogens transmission. According to EFSA they promote foodborne illness. Salmonella sp., Campylobacter sp., Listeria monocytogenes, Escherichia coli and Staphylococcus aureus are the most foodborne pathogens reported. Bacterial contamination levels remain at high level, particularly in Europe, despite regulatory efforts to address the situation. The need of new diagnostic tools is crucial. Ideally, tests easy to perform, enough accurate and low cost. The present work talk about optimization of a multiplex PCR (mPCR) test used to detect 5 foodborne contaminants: Salmonella sp., Campylobacter sp., L. monocytogenes, E. coli and S. aureus. For specificity evaluation, 5 PCR amplification reference DNA were used respectively: 103bp, 174bp, 151bp, 121bp and 136bp. No amplification was observed when primers and DNA from mismatching species were subject to PCR amplification. Furthermore, the sensitivity of this assay was evaluated by using serial dilutions of DNA extracted from clean 1CFU culture of each pathogen. This assay will be optimized by using Real-Time PCR and DNA plasmids containing a single copy of each gene, towards a new and rapid test for food and food manipulated surfaces control. Results are promising and allow us to postulate the design of an accurate and useful assay for bacterial control

Métodos práticos para cálculos de dietas para suplementação animal.

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Utilização da mandioca na alimentação de ruminantes na Amazônia.

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Biochar/Zinc Oxide Composites as Effective Catalysts for Electrochemical CO2 Reduction

Novel electrocatalysts based on zinc oxide (ZnO) and biochars are prepared through a simple and scalable route and are proposed for the electrocatalytic reduction of CO2 (CO2RR). Materials with different weight ratios of ZnO to biochars, namely, pyrolyzed chitosan (CTO) and pyrolyzed brewed waste coffee (CBC), are synthesized and thoroughly characterized. The physicochemical properties of the materials are correlated with the CO2RR to CO performance in a comprehensive study. Both the type and weight percentage of biochar significantly influence the catalytic performance of the composite. CTO, which has pyridinic- and pyridone-N species in its structure, outperforms CBC as a carbon matrix for ZnO particles, as evidenced by a higher CO selectivity and an enhanced current density at the ZnO_CTO electrode under the same conditions. The study on various ZnO to CTO weight ratios shows that the composite with 40.6 wt % of biochar shows the best performance, with the CO selectivity peaked at 85.8% at -1.1 V versus the reversible hydrogen electrode (RHE) and a CO partial current density of 75.6 mA cm-2 at -1.3 V versus RHE. It also demonstrates good stability during the long-term CO2 electrolysis, showing high retention in both CO selectivity and electrode activity