817 research outputs found
Clinical experience with an epoxy resin adhesive for direct bonding of orthodontic attachments*
KIMAn epoxy resin formulation developed in the Dental Research Unit has been subjected to further clinical trials. Six patients, were used in the study. They were divided into two age groups and all the teeth, including the first molars, bonded. Rubber dam was used to keep the crowns dry during the setting period of the resin. In the younger group the mean failure rates were 27 per cent for anterior teeth and 70 per cent for the first molars. In the older group these rates were 11 per cent for incisors, 11 per cent for canines, 20 per cent for premolars and 20 per cent for first molars. While no figures are available in the literature relating to direct bonding to first molars, the results obtained in this study for the other teeth compare favourably with data previously published by other authors after trials using other types of cement
Origin of Listeria monocytogenes on meat products
Listeria monocytogenes is a relevant food safety hazard in ready to eat products. Inactivation during processing, prevention of recontamination and control of multiplication are the main instruments to secure the safety of meat products. Intensive microbiological monitoring of products and the production environment are valuable tools to assess the level of control in a meat processing plant. During the course of a year all isolates found during hygiene monitoring at a meat processing plant were stored at -70 degrees Celsius. A total of 94 L. monocytogenes isolates have been analyzed by pulsed-field gel electrophoresis (PFGE) and were divided into 30 different types
Vijftig jaar monitoring en beheer van de Friese en Groninger kwelderwerken: 1960-2009
Dit WOt-werkdocument is een update van het kwelderboek uit 2001 en gaat ook over de bescherming door de kwelderwerken tegen de Allerheiligenvloed van 2006, over de Kaderrichtlijn Water en over de Sylt Conferentie van 2010. In 2007 verscheen in de WOT IN serie al een deel over Monitoring van kwelders in de Waddenzee, met beheermaatregelen voor alle kwelders (www.waddenzee.nl/Kwelders.1982.0.html). In de publicaties is ook aandacht voor beweiding, vegetatiekaarten, veroudering van de vegetatie, zeegras, grondwerk, ontwatering, en duurzaamheid van de rijshoutdammen
Evidence for the involvement of tyrosine-69 in the control of stereospecificity of porcine pancreatic phospholipase A2
We have studied the role of Tyr-69 of porcine pancreatic phospholipase A2 in catalysis and substrate binding, using site-directed mutagenesis. A mutant was constructed containing Phe at position 69. Kinetic characterization revealed that the Phe-69 mutant has retained enzymatic activity on monomeric and micellar substrates, and that the mutation has only minor effects on kcat and Km. This shows that Tyr-69 plays no role in the true catalytic events during substrate hydrolysis. In contrast, the mutation has a profound influence on the stereospecificity of the enzyme. Whereas the wild-type phospholipase A2 is only able to catalyse the degradation of sn-3 phospholipids, the Phe-69 mutant hydrolyses both the sn-3 isomers and, at a low (1-2%) rate, the sn-1 isomers. Despite the fact that the stereospecificity of the mutant phospholipase has been altered, Phe-69 phospholipase still requires Ca2+ ions as a cofactor and also retains its specificity for the sn-2 ester bond. Our data suggest that in porcine pancreatic phospholipase A2 the hydroxyl group of Tyr-69 serves to fix and orient the phosphate group of phospholipid monomers by hydrogen bonding. Because no such interaction can occur between the Phe-69 side-chain and the phosphate moiety of the substrate monomer, the mutant enzyme loses part of its stereospecificity but not its positional specificity
Report of the Horse Mackerel Exchange and Workshop 2006
Following a recommendation from PGCCDBS, a workshop on age calibration of horse mackerel was carried out. The workshop was preceded by an exchange. The objectives were: to improve the quality of horse mackerel readings by international calibration. In particular, attempt to resolve the observed differences between countries. Estimate the accuracy and precision of the age readings before and after the intercalibration. Take into account differences between areas and methods. Training of new horse mackerel readers
Towards a methodology for the engineering of event-driven process applications
Successful applications of the Internet of Things such as smart cities, smart logistics, and predictive maintenance, build on observing and analyzing business-related objects in the real world for business process execution and monitoring. In this context, complex event processing is increasingly used to integrate events from sensors with events stemming from business process management systems. This paper describes a methodology to combine the areas and engineer an event-driven logistics processes application. Thereby, we describe the requirements, use cases and lessons learned to design and implement such an architecture
Seroconversion to HCoV-NL63 in Rhesus Macaques
HCoV-NL63 is a recently identified respiratory virus. Its pathogenesis has not been fully unraveled because an animal model is currently lacking. Here we examined whether rhesus macaques encounter HCoV-NL63 infections during life, by examining the levels of antibodies to HCoV-NL63 in time. The animals were followed for 7 up till 19 years, and in three animals we observed a steep rise in antibodies during follow up, indicative of a natural infection with HCoV-NL63
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