Boven titel staat vermeld: De symbiose van biologie en technologie. Zowel vanuit het Applied Science onderwijs als vanuit het werkveld kwam er meer vraag om biologische expertise toe te voegen aan het bestaande lectoraat Thin Films & Functional Materials.
The age estimation of biological traces is one of the holy grails in forensic investigations. We developed a method for the age estimation of semen stains using fluorescence spectroscopy in conjunction with a stoichiometric ageing model. The model describes the degradation and generation rate of proteins and fluorescent oxidation products (FOX) over time. The previously used fluorimeter is a large benchtop device and requires system optimization for forensic applications. In situ applications have the advantage that measurements can be performed directly at the crime scene, without additional sampling or storage steps. Therefore, a portable fiber-based fluorimeter was developed, consisting of two optimized light-emitting diodes (LEDs) and two spectrometers to allow the fluorescence protein and FOX measurements. The handheld fiber can be used without touching the traces, avoiding the destruction or contamination of the trace. In this study, we have measured the ageing kinetics of semen stains over time using both our portable fluorimeter and a laboratory benchtop fluorimeter and compared their accuracies for the age estimation of semen stains. Successful age estimation was possible up to 11 days, with a mean absolute error of 1.0 days and 0.9 days for the portable and the benchtop fluorimeters, respectively. These results demonstrate the potential of using the portable fluorimeter for in situ applications.
Dark homogenous fungal-based layers called biofinishes and vegetable oils are keyingredients of an innovative wood protecting system. The aim of this study was todetermine which of the vegetable oils that have been used to generate biofinishes onwood will provide carbon and energy for the biofinish-inhabiting fungus Aureobasidiummelanogenum, and to determine the effect of the oil type and the amount of oil on thecell yield. Aureobasidium melanogenum was cultivated in shake flasks with differenttypes and amounts of carbon-based nutrients. Oil-related total cell and colony-formingunit growth were demonstrated in suspensions with initially 1% raw linseed,stand linseed, and olive oil. Oil-related cell growth was also demonstrated with rawlinseed oil, using an initial amount of 0.02% and an oil addition during cultivation. Nilered staining showed the accumulation of fatty acids inside cells grown in the presenceof oil. In conclusion, each tested vegetable oil was used as carbon and energysource by A. melanogenum. The results indicated that stand linseed oil provides lesscarbon and energy than olive and raw linseed oil. This research is a fundamental stepin unraveling the effects of vegetable oils on biofinish formation.
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