Filters

2015 - 201912020 - 20232

More filters

2022 - 20243
Reset filters

Settings

search.filters.applied.f.access: openAccess × DDC: 530 × DDC: 540 × DDC: 610 × Type: Text ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Cryo-printed microfluidics enable rapid prototyping for optical-cell analysis
    (Heidelberg : Springer, 2022) Garmasukis, Rokas; Hackl, Claudia; Dusny, Christian; Elsner, Christian; Charvat, Ales; Schmid, Andreas; Abel, Bernd
    This paper highlights an innovative, low-cost rapid-prototyping method for generating microfluidic chips with extraordinary short fabrication times of only a few minutes. Microchannels and inlet/outlet ports are created by controlled deposition of aqueous microdroplets on a cooled surface resulting in printed ice microstructures, which are in turn coated with a UV-curable acrylic cover layer. Thawing leaves an inverse imprint as a microchannel structure. For an exemplary case, we applied this technology for creating a microfluidic chip for cell-customized optical-cell analysis. The chip design includes containers for cell cultivation and analysis. Container shape, length, position, and angle relative to the main channel were iteratively optimized to cultivate and analyze different cell types. With the chip, we performed physiological analyses of morphologically distinct prokaryotic Corynebacterium glutamicum DM1919, eukaryotic Hansenula polymorpha RB11 MOX-GFP, and phototrophic Synechocystis sp. PCC 6803 cells via quantitative time-lapse fluorescence microscopy. The technology is not limited to rapid prototyping of complex biocompatible microfluidics. Further exploration may include printing with different materials other than water, printing on other substrates in-situ biofunctionalization, the inclusion of electrodes and many other applications.
  • Thumbnail Image
    Item
    Supervised discriminant analysis for droplet micro-magnetofluidics
    (Heidelberg : Springer, 2015) Lin, Gungun; Fomin, Vladimir M.; Makarov, Denys; Schmidt, Oliver G.
    We apply the technique of supervised discriminant analysis (SDA) for in-flow detection in droplet-based magnetofluidics. Based on the SDA, we successfully discriminate bivariant droplets of different volumes containing different encapsulated magnetic content produced by a GMR-based lab-on-chip platform. We demonstrate that the accuracy of discrimination is superior when the correlation of variables for data training is included to the case when the spatial distribution of variables is considered. Droplets produced with differences in ferrofluid concentration of 2.5 mg/ml and volume of 200 pl have been identified with high accuracy (98 %), indicating the significance of SDA for e.g. the discrimination in magnetic immuno-agglutination assays. Furthermore, the results open the way for the development of a unique magnetofluidic platform for future applications in multiplexed droplet-based barcoding assays and screening.
  • Thumbnail Image
    Item
    Physiological Parameters Relevant to Dissolution Testing - Hydrodynamic Considerations (rev. and suppl. version)
    (Tübingen : Universitätsbibliothek Tübingen, 2023) Diebold, Steffen M.
    The first two sections of the monograph present an introduction into basic hydrodynamics relevant to in vitro dissolution testing including V. G. Levichs convective diffusion theory and the authors combination model. This part is followed by hydrodynamic considerations of in vivo dissolution including hydrodynamic problems inherent to in vivo bioavailability of solid oral dosage forms. Hydrodynamics in the upper GI tract contribute to in vivo dissolution. Our ability to forecast dissolution of poorly soluble drugs in vitro depends on our knowledge of and ability to control hydrodynamics as well as other factors influencing dissolution. Provided suitable conditions (apparatus, hydrodynamics, media) are chosen for the dissolution test, it seems possible to predict dissolution limitations to the oral absorption of drugs and to reflect variations in hydrodynamic conditions in the upper GI tract. The fluid volume available for dissolution in the gut lumen, the contact time of the dissolved compound with the absorptive sites and the particle size have been identified as the main hydrodynamic determinants for the absorption of poorly soluble drugs in vivo. The influence of these factors is usually more pronounced than that of the motility pattern or the gastrointestinal flow rates per se.