Computational Determination of Air Valves Capacity Using CFD Techniques

[EN] The analysis of transient flow is necessary to design adequate protection systems that support the oscillations of pressure produced in the operation of motor elements and regulation. Air valves are generally used in pressurized water pipes to manage the air inside them. Under certain circumstances, they can be used as an indirect control mechanism of the hydraulic transient. Unfortunately, one of the major limitations is the reliability of information provided by manufacturers and vendors, which is why experimental trials are usually used to characterize such devices. The realization of these tests is not simple since they require an enormous volume of previously stored air to be used in such experiments. Additionally, the costs are expensive. Consequently, it is necessary to develop models that represent the behaviour of these devices. Although computational fluid dynamics (CFD) techniques cannot completely replace measurements, the amount of experimentation and the overall cost can be reduced significantly. This work approaches the characterization of air valves using CFD techniques, including some experimental tests to calibrate and validate the results. A mesh convergence analysis was made. The results show how the CFD models are an efficient alternative to represent the behavior of air valves during the entry and exit of air to the system, implying a better knowledge of the system to improve it.This research was funded by the Program Fondecyt Regular, grant number 1180660.García-Todolí, S.; Iglesias Rey, PL.; Mora Melia, D.; Martínez-Solano, FJ.; Fuertes-Miquel, VS. (2018). Computational Determination of Air Valves Capacity Using CFD Techniques. Water. 10(10):1-16. https://doi.org/10.3390/w10101433S1161010Liou, C. P., & Hunt, W. A. (1996). Filling of Pipelines with Undulating Elevation Profiles. 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Improved Canine and Human Visceral Leishmaniasis Immunodiagnosis Using Combinations of Synthetic Peptides in Enzyme-Linked Immunosorbent Assay

Visceral leishmaniasis is endemic in many areas of tropical and subtropical America where it constitutes a significant public health problem. It is usually diagnosed by enzyme-linked immunosorbent assays (ELISA) using crude Leishmania antigens, but a variety of other immunological methods may also be applied. Although these approaches are useful, historically their sensitivity and specificity have often been compromised by the use of complex mixtures of antigens. In this context, the use of combinations of purified, well-characterized antigens appears preferable and may yield better results. In the present study, combinations of peptides derived from the previously described Leishmania diagnostic antigens A2, NH, LACK and K39 were used in ELISA against sera from 106 dogs and 44 human patients. Improved sensitivities and specificities, close to 100%, for both sera of patients and dogs was observed for ELISA using some combinations of the peptides, including the detection of VL in dogs with low anti-Leishmania antibody titers and asymptomatic infection. So, the use of combinations of B cell predicted synthetic peptides derived from antigens A2, NH, LACK and K39 may provide an alternative for improved sensitivities and specificities for immunodiagnostic assays of VL

The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

Seroreactivity against raw insect-derived recombinant KMPII, TRYP, and LACK Leishmania infantum proteins in infected dogs

The recombinant proteins KMPII, TRYP, and LACK of Leishmania infantum were produced in baculovirus-infected Trichoplusia ni larvae and used to analyze the seroreactivity of 165 dog serum samples by the multiple-well ELISA technique (57 infected dogs with clinical signs, 46 naturally infected and 11 experimentally infected; and 108 non-infected dogs, 76 from non-endemic areas and 32 from endemic areas). Recombinant (r) KMPII was the most recognized antigen, as the majority of infected dogs seroreacted against it (0.75). This is the first report of seroreactivity against rTRYP (0.51) and rLACK (0.42) in L. infantum-infected dogs, since previous studies using recombinant TRYP and LACK proteins produced in prokaryotic systems failed to detect specific seroreactivity. All non-infected dogs were negative for rTRYP and rLACK, and only one of the 32 from endemic areas seroreacted against rKMPII. The results demonstrate that L. infantum-infected dogs develop humoral immunity against rKMPII, rTRYP, and rLACK antigens. There was substantial agreement between crude total L. infantum antigen (CTLA)-based ELISA and rKMPII ELISA (κ = 0.664), although this was higher than that found between the CTLA-based ELISA and rTRYP (κ = 0.427) or rLACK (κ = 0.343) ELISA, which can be interpreted as fair and moderate agreement, respectively. Ninety-three percent of the infected dogs analyzed developed specific antibodies against at least one of these three recombinant antigens. When the three recombinant antigen-based ELISA techniques were evaluated in parallel, almost perfect agreement (κ = 0.880) with CTLA-based ELISA was observed, with a specificity of 0.97 and a sensitivity of 0.93 in relation to CTLA-based ELISA. Further studies using purified recombinant antigens in a single-well test or individually, depending on the objective of the study, are warranted. © 2009 Elsevier B.V. All rights reserved

Absolute Quantification of Gold Nanoparticles with Femtomolar Accuracy Using Inductively Coupled Plasma Atomic Emission Spectroscopy

Here we describe a label-free method for the detection and absolute quantification of gold nanoparticles (AuNPs). Inductively coupled plasma atomic emission spectroscopy (ICP-AES) is used to detect less than a nanogram of AuNPs from complex unpurified biological samples. This corresponds to approximately femtomolar concentration range of AuNPs. ICP-AES is a nonoptical analytical technique which is unaffected by optically active molecules, opaque solutions, and organic or inorganic contaminants. It is therefore superior to traditional methods of detecting AuNPs based on the distinctive extinction peak in the visible spectrum. This method is compatible with high-throughput automated applications in life science and environmental research

Bromine isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry with a conventional sample introduction system

A simple and accurate methodology for Br isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) with pneumatic nebulization for sample introduction was developed. The Br+ signals could be measured interference-free at high mass resolution. Memory effects for Br were counteracted using 5 mmol L-1 of NH4OH in sample, standard, and wash solutions. The major cation load of seawater was removed via cation exchange chromatography using Dowex 50WX8 resin. Subsequent Br preconcentration was accomplished via evaporation of the sample solution at 90 °C, which did not induce Br losses or isotope fractionation. Mass discrimination was corrected for by external correction using a Cl-matched standard measured in a sample-standard bracketing approach, although Sr, Ge, and Se were also tested as potential internal standards for internal correction for mass discrimination. The δ81Br (versus standard mean ocean bromide (SMOB)) values thus obtained for the NaBr isotopic reference material NIST SRM 977 and for IRMM BCR-403 seawater certified reference material are in agreement with literature values. For NIST SRM 977, the 81Br/79Br ratio (0.97291) was determined with a precision ≤0.08‰ relative standard deviation (RSD).A simple and accurate methodology for Br isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) with pneumatic nebulization for sample introduction was developed. The Br+ signals could be measured interference-free at high mass resolution. Memory effects for Br were counteracted using 5 mmol L-1 of NH4OH in sample, standard, and wash solutions. The major cation load of seawater was removed via cation exchange chromatography using Dowex 50WX8 resin. Subsequent Br preconcentration was accomplished via evaporation of the sample solution at 90 A degrees C, which did not induce Br losses or isotope fractionation. Mass discrimination was corrected for by external correction using a Cl-matched standard measured in a sample-standard bracketing approach, although Sr, Ge, and Se were also tested as potential internal standards for internal correction for mass discrimination. The delta Br-81 (versus standard mean ocean bromide (SMOB)) values thus obtained for the NaBr isotopic reference material NIST SRM 977 and for IRMM BCR-403 seawater certified reference material are in agreement with literature values. For NIST SRM 977, the Br-81/Br-79 ratio (0.97291) was determined with a precision a parts per thousand currency sign0.08aEuro degrees relative standard deviation (RSD)