A fluoropolymer membrane filter with through-holes was fabricated by photolithographic patterning and the dry etching method. 380,000 highly packed through-holes, each with a diameter of 7 µm were ...able to cover a whole area with a diameter of 13 mm. Ethylene tetrafluoroethylene (ETFE) was used as the membrane, which was suitable for the fluorescence detection of rare cells such as circulating tumor cells (CTCs) in human blood. The device fabrication for the size based capture of rare cells in blood such as CTCs is realized in this study.
In the field of microfluidics, it is possible to facilitate liquid transport through microsized holes with large slip lengths by lowering the friction at the interface between the flow and the inner ...surface of the holes. In this paper, we discuss the use of nonequilibrium atmospheric-pressure plasma to modify the surface wettability of microsized holes in glass substrates that are similar to those used as flow channels in glass microfiltration devices. In our experiments, liquid transport flows were driven by internal Laplace pressure differences based on the surface tensions of droplets placed on the front and back sides of the tested substrates.
Background: Exosome is one kind of extracellular vesicles that contain some kinds of RNAs. The clinical applications of exosomes are expected for diagnosis and treatment of diseases. However, ...existing isolation methods were inefficient and complicated. We developed highly efficient and easy to use exosome isolation spin column with a porous glass filter. Methods: The spin column with porous glass filter was developed by Asahi Glass Co., Ltd. Biological solution: serum and cell culture medium were passed through the filter using a conventional desk-top centrifugation. The capture efficiency of exosome was evaluated, and the captured exosome in the filter was observed using SEM. miRNA profiles from captured exosome was compared with ultracentrifuge (UC) and commercially available isolation kit. Results: Capture efficiency of exosome from cell culture medium with our spin column was more than 90% and the exosome-like vesicles in the filter was observed clearly by SEM. Coverage of RNA species with our spin column was clearly better than UC and other isolation kit. Summary/Conclusion: We developed exosome isolation method using porous glass filter. The capture efficiency and miRNA coverage of exosome were evaluated. The result showed our method was highly effective and easy to use.
We experimentally investigated electron transport in thin graphite films including tens of graphene layers. The samples were fabricated by mechanical peeling of graphite, e-beam lithography, metal ...deposition and lift-off. For some samples, Ar-ion bombardment was carried out prior to the metal deposition to enhance the electrical transparency of the contacts. We found that the Ar-ion bombardment significantly deteriorate the samples; the electron transport changes from the semimetallic behavior to the weak-localization behavior.
Electric conduction in thin graphite film was tuned by two gate electrodes to clarify how the gate electric field induces electric carriers in thin graphite. The graphite was sandwiched between two ...gate electrodes arranged in a top and bottom gate configuration. A scan of the top gate voltage generates a resistance peak in ambiploar response. The ambipolar peak is shifted by the bottom gate voltage, where the shift rate depends on the graphite thickness. The thickness-dependent peak shift was clarified in terms of the inter-layer screening length to the electric field in the double-gated graphite film. The screening length of 1.2 nm was experimentally obtained.
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