Hoseo University

Area-selective atomic layer deposition (area-selective ALD) has been extensively studied because of its versatility in nanotechnological applications. The priority focus in area-selective ALD is to achieve the desired selectivity; thus, most studies to date have been concentrated on the reaction mechanism of ALD on growth/nongrowth substrates or the development of novel methodologies to resolve the challenges associated with its implementation in high-volume manufacturing. In this study, we performed area-selective ALD of SiO2 on SiO2, where SiO2 was not grown on SiNx, and suggested area-selective ALD approaches that could simultaneously enhance selectivity and film quality. An NH3 plasma treatment was applied to functionalize the SiNx surface with more Si–NH bonds, which exhibited low reactivity toward Si precursors. Although the SiO2 surface was also functionalized with Si–NH bonds, it was not fully converted into Si–NH because of its thermodynamic nature at low temperatures. Consequently, the results showed that NH3 plasma pretreatment was effective in increasing selectivity. Therefore, we performed a layer-by-layer NH3 plasma treatment during the ALD of SiO2 to deposit high-quality films without losing selectivity. The SiO2 film was densified, as confirmed by x-ray reflection spectra without nitrogen impurity incorporation. Electrical property measurements of metal–oxide–semiconductor capacitors confirmed that this approach enabled simultaneous selectivity and SiO2 film-quality enhancement.

In genome-wide association studies, the HECT domain E3 ubiquitin-protein ligase 4 (HECTD4) gene was suggested to be associated with obesity-related traits and coffee consumption. However, the association of genetic variants between coffee consumption and obesity has not been tested in Koreans. Therefore, we investigated whether HECTD4 gene variants act as effect modifiers on the relationship between obesity and coffee.

This study analyzed the correlation between coffee consumption and obesity among 58,698 individuals representing the Health Examinees. Participants were categorized into obese (BMI ≥ 25.0 kg/m²) and nonobese (18.5 ≤ BMI < 23.0 kg/m²). Food consumption was assessed by a food frequency questionnaire.

We identified four HECTD4 gene variants associated with obesity-related traits and coffee consumption based on Bonferroni-corrected significance level (p < 0.00014). Furthermore, multivariate logistic regression analysis confirmed that the impact of coffee consumption on obesity differed based on the HECTD4 rs2074356 genotypes. A positive correlation between obesity and coffee consumption was observed, with a more pronounced effect in individuals with the G allele (OR = 1.61 for 1 to <2 cups/day, p = 1.89 × 10^-37; OR = 1.82 for ≥2 cups/day, p = 1.73 × 10^-42) than in those with the A allele (OR = 1.47 for 1 to <2 cups/day, p = 7.41 × 10^-17; OR = 1.45 for ≥2 cups/day, p = 7.24 × 10^-11).

Our findings suggest that the influence of coffee consumption on obesity may vary in Koreans depending on the HECTD4 gene variant.

A liquid crystal x-ray detector was manufactured by coating HgI2 on a thin glass substrate liquid crystal cell in guest–host (GH) mode. The HgI2 layer was produced using the particle-in-binder (PIB) method. A reflective optical system was constructed so that one pixel corresponds to a 45 × 45 µm2 area of the liquid crystal cell. A quantification process was established to convert liquid crystal images into x-ray images. As a result, the signal-to-noise ratio (SNR) was 50 when irradiated with 32 keV, 10 mR/cm2 x rays. In the liquid crystal x-ray detector, read noise decreases as the intensity of the light source increases. The full well capacity (FWC) of the image sensor was 100 ke, measured in the range of 25 ke to 70 ke, with a read noise of ∼1%. To achieve an SNR at the shot noise level, an FWC of 500 ke is required, with measurements taken in the 100–400 ke range. In this case, the read noise is less than 0.3%, and the measurement precision approaches the physical limit.