Gut microbes influence tumor development and progression in the intestines and may provide a novel paradigm for the treatment of colorectal cancer (CRC). Gut dysbiosis may be associated with the development and progression of CRC. Identifying the interactions between the colonic tract and gut microbiota may provide novel information relevant to CRC prevention. The present study examined the effects of butyrate-producing Butyricicoccus pullicaecorum (B. pullicaecorum) on mice with 1,2-dimethylhydrazine (DMH)-induced CRC and the microbial metabolite of B. pullicaecorum on CRC cells. Immunohistochemical staining of the mouse colon tissues and reverse transcription PCR of CRC cells were used to determine the protein and mRNA expression levels of the short-chain fatty acid (SCFA) transporter solute carrier family 5 member 8 (SLC5A8) and G-protein-coupled receptor 43 (GPR43). In CRC-bearing mice fed B. pullicaecorum, DMH-induced CRC regressed, body weight increased and serum carcinoembryonic antigen levels decreased. Notably, SLC5A8 and GPR43 were diffusely and moderately to strongly expressed in the neoplastic epithelial cells and underlying muscularis propria in the colons of the mice. In conclusion, administration of B. pullicaecorum or its metabolites improved the clinical outcome of CRC by activating the SCFA transporter and/or receptor. These results indicated that B. pullicaecorum was a probiotic with anti-CRC potential.

Among the strategies for growing one-dimensional nanostructures such as nanotubes and nanowires, a very viable approach is deposition of the desired material into a template with arrays of well-aligned nanochannels.[1±7] A competitive template with such characteristics is the porous anodic aluminum oxide (AAO) film, whose nanochannels can even laterally self-organize into hexagonally close-packed (hcp) domains exhibiting short-range order provided it is grown under specific anodization conditions. [8,9] It has been demonstrated that the range of the order can be further extended by several orders of magnitude using lithographic-guiding techniques, [4,10±12] and that the pore size distributions of such guided arrays are much narrower than those of the self-organized ones. The successful fabrication of such long-range-ordered nanochannel arrays, hereafter referred to simply as ordered arrays, has not only broadened the potential applications of AAO films but also opened possibilities for the fabrication of arrays of nanostructures arranged according to a custom-designed geometry. For example, one can envision an array with only part of it covered by nanodots or nanowires while the rest of the surface area remains empty. Depending on its geometry, such an array, with designed optical and electronic properties, could be used as a photonic crystal and/or a waveguide.[13±16] One of the viable approaches for fabricating such a custom-designed array is to grow the desired material into a template with a partially closed nanochannel array. Herein, we demonstrate a focused ion beam (FIB) directwrite lithographic method for selectively closing part of the channels of an ordered array on an AAO film in order to create a custom-designed nanochannel array. The initial ordered arrays were fabricated by FIB lithographic guiding techniques where the closure of the nanochannels within a certain area was achieved by raster scanning the FIB over the area, thus directly bombarding the AAO film. The successful fabrication of such a template with custom-designed nanochannel arrays opens up numerous possibilities for the creation of nanowire or nanodot arrays with desired geometric patterns. The fabrication process always starts from growing an ordered array by anodizing a finely polished aluminum sample that has been patterned with a guiding lattice on its surface. The lattice is a two-dimensional array of hcp concave pits created by FIB direct-write lithography. An ordered array is achieved when the lattice constant of the guiding lattice is carefully matched with the electrolyte and anodization voltage.[17] For the present work, we set the lattice constant, and therefore the spacing, of the ordered array to be 100 nm, and grew the nanochannels to a typical aspect ratio of larger than » 50. Figure 1a shows a micrograph of a typical ordered array on an AAO film taken by scanning with a 50 keV gallium FIB with a beam current of 1.1 pA and a diameter of » 10 nm over the sample while collecting the secondary electron signal to provide th...

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Cu nano-particles (Cu-NPs) were embedded into the SiO2 layer of a Cu/SiO2/Pt structure to examine their influence on resistive switching characteristics. The device showed a reversible resistive switching behavior, which was due to the formation and rupture of a Cu-conducting filament with an electrochemical reaction. The Cu-NPs enhanced the local electric field within the SiO2 layer, which caused a decrease in the forming voltage. During successive switching processes, the Cu-NP was partially dissolved, which changed its shape. Therefore, the switching voltages were not reduced. Moreover, the Cu-NPs caused a non-uniform Cu concentration within the SiO2 layer; thus, the Cu-conducting filament should be formed in a high Cu concentration region, which improves switching dispersion. The Cu-NPs within the SiO2 layer stabilize the resistive switching, resulting in a larger switching window and better endurance characteristics.

Anodization of tungsten in NaOH leads to the growth of a porous tungsten oxide layer with either irregular trenches or isolated nanobubbles. For anodic potentials between 30 to 40 V and NaOH concentrations of 2–3 M, nanobubbles with diameters of ∼40 nm form spontaneously and self-organize into hexagonal close-packed ordered arrays with a period of ∼60 nm. The nanobubbles are likely to be initiated by the electrostatic stress on the oxide film that could become more plastic under the influence of high-density anodic current. The ordered arrangement of the nanobubbles manifests a delicate balance of the stress on their surrounding oxide walls.

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Sputter-deposited V-doped SrZrO 3 (SZO) films were deposited on textured LaNiO 3 (LNO) bottom electrodes to investigate the resistance switching properties and reliabilities. The microstructures of the SZO and LNO films were characterized by x-ray diffraction. The resistance of the Al/V-doped SZO/LNO sandwich structures can be reversibly switched by operating with dc bias voltages or voltage pulses. The device with [100] orientated SZO film had better resistance switching properties and the resistance ratio was more than 1000. The effect of thermal treatment on resistance switching properties was investigated and different behaviour of the two leakage-states was found. Finally, the reliability of the device was also investigated. The device with the properties of reversible resistance switching and non-destructive readout is suitable for nonvolatile memory application.

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