Giant geometry modulation on magnetic proximity effect observed in isomeric oxide heterostructures

Magnetic proximity effect (MPE) is generally considered to occur at the magnetic-nonmagnetic material interface within a short-range space domain, while the structural geometry modulation on such an interface effect has not been explored. Here, we fabricate isomeric paramagnetic metallic IrO2 with rutile and anatase structures, respectively, on a ferrimagnetic insulating CoFe2O4, and study the MPE-induced magnetism by anomalous Hall effect (AHE) measurements. The rutile phase with layered structure shows a conventional AHE and identical coercive-field with CoFe2O4, indicating a concomitant magnetic switching as a result of a strong magnetic coupling at the interface. In contrast, the anatase phase with tetrahedral structure exhibits an unconventional AHE with negative coercive-field at low temperatures. Further analyses indicate that in anatase, the contribution that strongly couples with CoFe2O4 is dramatically suppressed while a giant frustration-like response emerges. Our findings reveal that the MPE-induced spin orders can be pronouncedly modulated by structural geometry

小特集：磁場閉じ込め核融合装置における水素原子分子輸送研究の新展開 ２．要素モデルの統合が実現する壁から プラズマまでを含めた中性粒子輸送研究

非接触をはじめとするダイバータプラズマの諸現象を理解するため，壁での粒子リサイクリング，荷電粒子，中性粒子を扱うコードの統合を進めている．水素分子には，電子状態のほか，回転および振動の内部自由度があり，分子活性化再結合をはじめとするプラズマ中の水素分子の各種の反応速度係数は，水素分子の始状態の振動・回転量子数により，数桁にわたって変化する．また，低温のプラズマでは，プラズマ中の電子やプロトン衝突による水素分子の振動・回転励起がプラズマのエネルギー損失チャンネルとして重要と考えられる．このため，水素分子の振動・回転状態を中性粒子やプラズマの輸送と組み合わせて解く統合モデルを開発した

Evaluation of the effects of mastication and swallowing on gastric motility using electrogastrography

Objectives : The influence of mastication and swallowing on gastric motor function was evaluated by electrogastrography (EGG) and abdominal ultrasonography. Methods: The subjects were 30 elderly patients with tubal feeding without mastication and swallowing (T group) and 30 elderly controls who processed food by mastication and swallowing (C group). Gastric motor function was percutaneously examined before and after the ingestion of 250 ml of a liquid diet using an electrogastrograph (NIPRO EGG, A&D, Tokyo, Japan). The cross-sectional area of the gastric antrum was measured at 1 and 30min after the start of ingestion of the liquid diet by external ultrasonography of the abdomen, and the gastric excretion function was evaluated. Furthermore, the spectral analysis of heart rate variability was performed using Holter electrocardiograms before and after ingestion. The low frequency power (LF power, 0.04-0.15 Hz), high frequency power (HF power, 0.15-0.40 Hz), and the LF/HF ratio were determined. Results: The peak amplitude at 3 cycles perminute (cpm)was significantly increased after ingestion in the C and T groups (p<0.05), and the ratio of increase was significantly lower in the T group (p<0.05). The mean amplitude for the brady-gastria and tachy-gastria was significantly higher in the T group than in the C group (p<0.05). The gastric excretion function, as evaluated by external ultrasonography of the abdomen, was significantly lower in the T group than in the C group (p<0.05). An analysis of heart rate variability demonstrated that the HF power, a parameter of parasympathetic activity, after ingestion was significantly higher in the C group than in the T group (p<0.05). No changes in LF power or LF/HF ratio, parameters of sympathetic activity, were induced by ingestion in either the C or T groups. Conclusions: The parasympathetic nerve dominantly controls gastric motor function, but autonomic nervous activity is reduced in patients who are unable to masticate and swallow food, resulting in adverse effects on gastric motor function and excretion function. Mastication and swallowing not only prepare food for passage from the oral cavity to the esophagus but are also important in terms of subsequent events that occur in stomach. It has been proposed that autonomic nervous activity might be involved in mastication and swallowing