Summary Background Non‐alcoholic fatty liver disease (NAFLD) is associated with colorectal neoplasia. Yet, NAFLD ranges from simple steatosis to steatohepatitis with advanced fibrosis. Aim To investigate the risk of colorectal neoplasia according to the presence and severity of NAFLD. Methods A total of 26 540 asymptomatic adults who underwent same day first‐time colonoscopy and abdominal ultrasonography as a health check‐up programme were analysed. NAFLD was diagnosed by ultrasonography. Advanced colorectal neoplasia was defined as an invasive cancer or adenoma that was at least 10 mm in diameter, had high‐grade dysplasia, or had villous histological characteristics or any combination thereof. Results NAFLD patients had a higher prevalence of any colorectal neoplasia (38.0% vs. 28.9%) and advanced colorectal neoplasia (2.8% vs. 1.9%) compared to those without NAFLD. In a multivariable model adjusted for age, sex, smoking, alcohol, body mass index, first‐degree family history of colorectal cancer, aspirin use and metabolic factors, the odd ratios comparing patients with NAFLD to those without were 1.10 [95% confidence interval (CI): 1.03–1.17] for any colorectal neoplasia and 1.21 (95% CI: 0.99–1.47) for advanced colorectal neoplasia. When NAFLD patients were further stratified according to the non‐invasive parameters of liver disease severity, the risk of any colorectal neoplasia or advanced colorectal neoplasia was higher for those with severe liver diseases than those with mild liver diseases. Conclusions The presence and severity of NAFLD were closely associated with any colorectal neoplasia and advanced colorectal neoplasia, suggesting that clinicians should be aware of the increased risk of colorectal neoplasia in patients with NAFLD.

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The phase-change characteristics of Ge 2 Sb 2 Te 5 /SiO 2 multilayered films with various bilayer thicknesses were investigated using high-resolution transmission electron microscopy. The change in the electrical sheet resistance of the films shows that the metastable face-centered cubic ͑fcc͒ structure formation was significantly affected by the bilayer thickness of the multilayer film. That is, compared with the single-layered Ge 2 Sb 2 Te 5 film, the multilayered films transformed to hexagonal at lower temperatures. In particular, the transition temperature region of the fcc structure with semiconductor properties was significantly reduced. We observed that as the bilayer thickness decreased and annealing temperature increased, the structure of the multilayer film was transformed into Ge-deficient and hexagonal phases such as GeSb 2 Te 4 and Sb 2 Te 3 . This behavior was induced by the out-diffusion of Ge atoms from the outer surface layer, which can be caused by a difference in thermal strain at the interface between the Ge 2 Sb 2 Te 5 and SiO 2 films.Phase-change random access memory ͑PRAM͒ is a leading candidate for next-generation, nonvolatile memory, because PRAM has a low technical barrier to access of the fabrication process, a simple device structure, and a short write/erase time. 1,2 GeTe-Sb 2 Te 3 pseudobinary compounds, such as Ge 2 Sb 2 Te 5 ͑GST225͒, which were first adopted for optical disks, have mostly been investigated as a PRAM active material, because these systems have proper melting points, crystallization temperatures, and rapid phase-change behavior. 3 Recently, based on extended X-ray absorption fine structure and X-ray absorption near-edge structure measurements, Kolobov et al. proposed that the phase transition between the amorphous and metastable cubic ͓NaCl-type face-centered cubic ͑fcc͔͒ phases involves an umbrella-flip behavior of Ge atoms between the tetrahedral and octahedral positions in a unit cell. 4 Specific structural characteristics determine the resistivity of the GeSbTe ͑GST͒:amorphous GST ͑a-GST͒ with its insulating phase, the metastable fcc structure with its semiconductor phase, and the hexagonal structure with its metallic phase. In the phase-change process, the a-GST is transformed to a hexagonal structure through the metastable fcc structure. With the understanding that a phase-change mechanism is based on microstructural change, the structural stability between a-GST and a metastable cubic has been considered for PRAM, because the stability critically affects the phase-change temperature and operation power of PRAM devices. For future high-density PRAM development, the nanometer dimensional scaling effect must be investigated, because GST film is very soft and structural change is acutely dependent on the incorporated atoms and on the circumstances that critically affect the phase-change properties.To date, a few studies have reported on the scaling effect of phase-change materials. 5-9 Lee et al. explained that the size dependence of the phase changes originates ...

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