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@PHDTHESIS{Kasahara:1015345,
      author       = {Kasahara, Keitaro},
      othercontributors = {Wiechert, Wolfgang and Magnus, Jørgen Barsett},
      title        = {{S}tructuring spatiotemporal oxygen environments for
                      microbial single-cell analysis in microfluidics},
      school       = {Rheinisch-Westfälische Technische Hochschule Aachen},
      type         = {Dissertation},
      address      = {Aachen},
      publisher    = {RWTH Aachen University},
      reportid     = {RWTH-2025-06324},
      pages        = {1 Online-Ressource : Illustrationen},
      year         = {2025},
      note         = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
                      University; Dissertation, Rheinisch-Westfälische Technische
                      Hochschule Aachen, 2025},
      abstract     = {Microbial single-cell analysis using microfluidics is a
                      promising method for studying microbial growth behavior in
                      detail under precisely controlled environments. However,
                      little effort has been made to incorporate spatiotemporal O2
                      control, a critical factor influencing microbial growth and
                      physiology. This dissertation explores various strategies
                      for establishing straightforward O2 control, temporal O2
                      control in the range of seconds to minutes, and spatial O2
                      control in the range of micrometers. First, a comprehensive
                      experimental platform was developed that is transferable to
                      microbial single-cell analysis within various formats of
                      microfluidic devices. Using a low-cost 3D-printed
                      mini-incubator surrounding the air-permeable PDMS
                      microfluidic chip, the O2 concentration in the microfluidic
                      chip was controlled. The O2 sensing method using FLIM and an
                      O2-sensitive dye was also implemented, allowing direct
                      measurement of the O2 availability inside the fluid
                      channels. Subsequent imaging with timelapse microscopy and
                      deep-learning-based image analysis provided a solid platform
                      for data analysis. Furthermore, a double-layer microfluidic
                      chip was developed to implement spatiotemporal O2 control in
                      microbial single-cell analysis. The newly developed
                      microfluidic platform could reproduce O2 oscillations
                      occurring within seconds to minutes, thus enabling
                      time-resolved microbial growth analysis at single-cell
                      resolution. The case studies were performed by studying the
                      aerobic and anaerobic growth and adaptation of E. coli and
                      C. glutamicum. The growth analysis results revealed
                      aerobic/anaerobic specific growth and growth adaptation in
                      response to O2 oscillations, insights that cannot be
                      obtained using conventional cultivation setups. Lastly,
                      several different designs of the double-layer microfluidic
                      chip were introduced to achieve spatial O2 control in
                      microbial single-cell analysis in the range from millimeters
                      down to micrometers. The experimental results demonstrated
                      the capability of spatial O2 control by diffusion. The
                      proposed concepts and devices are expected to be used for
                      further microbial growth characterization under
                      spatiotemporally structured O2 microenvironments.},
      cin          = {420410},
      ddc          = {620},
      cid          = {$I:(DE-82)420410_20140620$},
      typ          = {PUB:(DE-HGF)11},
      doi          = {10.18154/RWTH-2025-06324},
      url          = {https://publications.rwth-aachen.de/record/1015345},
}