Towards B-doped p-BaSi2 films on Si substrates by co-sputtering of BaSi2, Ba, and B-doped Si targets

BaSi2 is one of the emerging materials for thin-film solar cell applications; hence the conductivity control by impurity doping is of great importance. The formation of B-doped p-BaSi2 films has been achieved by molecular beam epitaxy and vacuum evaporation. We fabricated B-doped BaSi2 films on Si substrates at 600 °C by co-sputtering BaSi2, Ba, and B-doped Si targets, followed by post-annealing at 900 °C or 1000 °C for 5 min in an Ar atmosphere. Contrary to expectations, as-grown sample and the sample annealed at 900 °C showed n-type conductivity, while the sample annealed at 1000 °C showed p-type conductivity. The reason for the n-type conductivity was discussed based on first-principles calculationconsidering the presence of oxygen atoms in the order of 1021 cm−3. The n-type conductivity for B-doped BaSi2 is possible only when both the B and O atoms being a substitution impurity are in the same Si4 tetrahedron

Mutation site-specific differences in arrhythmic risk and sensitivity to sympathetic stimulation in the LQT1 form of congenital long QT syndrome Multicenter study in Japan

AbstractObjectivesWe sought to compare the arrhythmic risk and sensitivity to sympathetic stimulation of mutations located in transmembrane regions and C-terminal regions of the KCNQ1channel in the LQT1 form of congenital long QT syndrome (LQTS).BackgroundThe LQT1 syndrome is frequently manifested with variable expressivity and incomplete penetrance and is much more sensitive to sympathetic stimulation than the other forms.MethodsSixty-six LQT1 patients (27 families) with a total of 19 transmembrane mutations and 29 patients (10 families) with 8 C-terminal mutations were enrolled from five Japanese institutes.ResultsPatients with transmembrane mutations were more frequently affected based on electrocardiographic (ECG) diagnostic criteria (82% vs. 24%, p < 0.0001) and had more frequent LQTS-related cardiac events (all cardiac events: 55% vs. 21%, p = 0.002; syncope: 55% vs. 21%, p = 0.002; aborted cardiac arrest or unexpected sudden cardiac death: 15% vs. 0%, p = 0.03) than those with C-terminal mutations. Patients with transmembrane mutations had a greater risk of first cardiac events occurring at an earlier age, with a hazard ratio of 3.4 (p = 0.006) and with an 8% increase in risk per 10-ms increase in corrected Q-Tend. The baseline ECG parameters, including Q-Tend, Q-Tpeak, and Tpeak-end intervals, were significantly greater in patients with transmembrane mutations than in those with C-terminal mutations (p < 0.005). Moreover, the corrected Q-Tend and Tpeak-end were more prominently increased with exercise in patients with transmembrane mutations (p < 0.005).ConclusionsIn this multicenter Japanese population, LQT1 patients with transmembrane mutations are at higher risk of congenital LQTS-related cardiac events and have greater sensitivity to sympathetic stimulation, as compared with patients with C-terminal mutations

鹿児島県指宿市南摺ヶ浜遺跡から出土した古墳時代人骨

鹿児島県指宿市に所在する南摺ヶ浜遺跡の2007年度の発掘調査で壺棺墓から３体、円形周溝墓から１体、土坑墓から１体の合計５体の人骨が出土した。いずれも保存状態は悪い。年齢の推定を行ったところ、南摺ヶ浜遺跡では壺棺墓は子供の埋葬に用いられたことが、円形周溝墓や土壙墓は成人の埋葬に用いられたことがわかった