Suchergebnisse

A serosurvey of 349 military working horses and 231 military working dogs was conducted in ten sites in Morocco in 2012. This survey revealed a high level of exposure of these animals to flaviviruses: seroprevalence rates of 60% in horses and of 62% in dogs were observed using a competitive West Nile virus (WNV) enzyme-linked immunosorbent assay (cELISA). Seroneutralization test results showed that the majority of cELISA-positive results were due to exposure to WNV. Further assays conducted in vaccinated horses with a DIVA (Differentiating Infected from Vaccinated Animals) test indicated that anti-WNV antibodies had been stimulated through WNV natural infection. Moreover, in both species, seroneutralization tests suggested an exposure to Usutu virus (USUV). Data analysis did not show any significant difference of cELISA seropositivity risk between horses and dogs. Dogs may thus represent an interesting alternative to equines for the serological surveillance of WNV or USUV circulation, especially in areas where equine vaccination precludes passive surveillance (based on the detection of West Nile fever cases) in horses.

In the framework of the Phos4You (P4Y) project funded by Interreg North West (NW) Europe 6 different Phosphorous(P)-recovery technologies will be demonstrated. The University of Liège is developing one of the processes, called PULSE (Phosphorus ULiège Sludge Extraction) process, to recover P from fully or partially dried sewage sludge. The PULSE process is a modification of the PASCH process developed at RWTH Aachen to extract P from sewage sludge ashes [1]. In the PULSE process P is recovered from partially or fully dried sludge using acidic leaching. Purification of the leach liquor will be carried out by reactive extraction to separate P and other nutrients from co-leached metals. Finally, depending on the leaching and extraction approach used above, the final product of the PULSE process can either be obtained as phosphate salt or phosphoric acid. Nevertheless, production of novel P products requires a novel standardized methodology for its quality assessment and valorisation on the market. In the first part of the research, the experiments for the unit operations of the PULSE process are conducted at lab-scale and metals, P and other macronutrient content in each step of the process sequence is monitored and benchmarked against the legislative limits. Comparison of the standardized sludge digestion method with nitric acid and/or aqua regia with modified sulphuric and hydrochloric acid will be conducted in order to establish a standard for sludge characterization especially for heavy metals determination. The data obtained for the different process options of each unit operation are evaluated using the methodology of 'Cascaded Option Trees' [2] to select the most feasible and optimum option. A solid-liquid equilibrium speciation model developed in MATLAB is further used for optimizing process parameters. In the second step, the PULSE process will be demonstrated on a pilot-plant scale at 4 different locations in NW Europe. The novel P product will be thoroughly analysed using quality methods selected by project partners responsible for quality assessment in the P4Y project for P availability and inorganic characterization, which provides feedback to the technology producer for improvement. In the presentation, the concept of the PULSE process will be explained along with the results from the lab experiments and evaluation of process options. The concept of solid-liquid equilibrium speciation model and its application to optimize the PULSE process operation will also be presented. The relation between the quality of the P source and P product will be showcased. Further comparison of the quality of PULSE product with the regional and EU regulations on P fertilizers will also be presented. ; Peer reviewed

Objective: Compliance is considered to be a major property influencing the long term performances of synthetic vascular substitutes that could play a role in anastomotic false aneurysm and intimal hyperplasia stenosis onset. Over the last decades, manufacturers have tried to develop substitutes that mechanically mimic arterial properties and avoid a compliance mismatch at the anastomoses in particular. However, data are missing about how initial compliance properties could change with time. The goal of this study was to evaluate how the compliance of vascular grafts evolves under cyclic loading conditions in vitro. Methods: The compliance of three different models of commercially available textile polyethylene terephthalate (PET) grafts was evaluated. Tests were performed with and without their original coating. Compliance was assessed with a specific device dedicated to measure the deformations undergone by a graft under cyclic pressure loading conditions, using image analysis software. In each experiment, image analysis was performed under 60 and 140 mmHg pressure loading conditions at loading start (H0) and after three, six, and 24 h (H3, H6, H24) loading time. Average radial, longitudinal, and volumetric compliance was calculated from the obtained images. Results: Twenty-four samples were tested. Results demonstrate that all values decreased significantly within only a few hours. On average, the loss of compliance after 3 h of cyclic loading ranged on average from 35% for longitudinal compliance to 39% for radial compliance and 37% (p < .050) for volume compliance. After 24 h, the loss of radial, longitudinal and volume compliance was respectively 63 ± 3%, 60.5 ± 2% and 61 ± 7%. Conclusion: In this in vitro model, PET graft compliance has already decreased significantly within 3 h. The rapid loss of compliance identified in this experimental study helps explain the mismatch mentioned in clinical observations.