Browsing by Subject "SPR"

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  • Nissinen, Ulla (Helsingfors universitet, 2017)
    Quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) spectroscopy are methods measuring mass changes on solid surface. During measurement fluid flows over sensor. The aim of this study was to find out if it's possible to culture a biofilm using QCM and SPR methods and compare biofilms with those cultured in test tubes under static fluid conditions. Enrofloxacin antibiotic was tested against biofilm cultured in SPR. Biofilms were imaged electron microscopically. Bacteria used were Staphylococcus pseudintermedius and Corynebacterium auriscanis and a combination of those. Biofilm was successfully cultured by both methods repeatably. S.pseudintermedius formed a biofilm, but C.auriscanis didn't. Together S.pseudintemedius and C.auriscanis formed thicker biofilm than S.pseudintermedius alone. There were difference between biofilms depending on culturing conditions. Biofilm covered the surface quicker and bacterial density was higher under flowing conditions than static fluid. The growth of biofilm was ceased during enrofloxacin feeding, but not destroyed. Growth continued after stopping enrofloxacin feeding. QCM and SPR methods are suitable for culturing biofilms. They measure mass changes on solid surface but tell nothing about the architecture of biofilm. QCM and SPR could be good methods for studying compounds destroying biofilm matrix or trying to find coating materials to prevent bacterial adhesion.
  • Peng, Shikui (Suomen metsätieteellinen seura, 1987)
    A study of a 194.3 ha area of forest land dominated by Norway spruce and Scots pine in central S. Finland. A general procedure is presented and discussed for integrating data from permanent sample plots and from satellite images for continuous forest inventory of large areas and for compartment estimations. Methods for estimation, updating and statistical analysis are examined.