Coercivity enhancement of Dy-coated Nd-Fe-B flakes by crystallization

The coercivity of isotropic Dy-coated Nd-Fe-B flakes was enhanced by crystallization and simultaneous diffusion of Dy from their surfaces. Amorphous Dy-coated Nd-Fe-B flakes were crystallized by heating them to 923 K 2over a 2 min period followed by rapid cooling. During crystallization, the Dy on the surface diffused into the flakes. This low-temperature rapid annealing produced flakes with fine grains and the Dy diffusion enhanced their coercivity. The coercivity after crystallization increased with increasing Dy layer thickness, although the remanence decreased when the layer thickness exceeded 3 μm. Thick coatings of over 6 μm resulted in the formation of DyFe2, which degraded the magnetic properties of the crystallized flakes. Flakes with a 3-μm-thick coating exhibited excellent magnetic properties after annealing: They had a coercivity of 1880 kA/m and a remanence of 78 emu/g. This coercivity is approximately 500 kA/m higher than that of uncoated flakes, whereas the remanence is comparable to that of uncoated flakes

A multicenter prospective registry of Borden type I dural arteriovenous fistula: results of a 3-year follow-up study

PURPOSE: Although intracranial dural arteriovenous fistula (DAVF) without retrograde leptomeningeal venous drainage (Borden type I) is reported to have a benign nature, no study has prospectively determined its clinical course. Here, we report a 3-year prospective observational study of Borden type I DAVF. METHODS: From April 2013 to March 2016, consecutive patients with DAVF were screened at 13 study institutions. We collected data on baseline characteristics, clinical symptoms, angiography, and neuroimaging. Patients with Borden type I DAVF received conservative care while palliative intervention was considered when the neurological symptoms were intolerable, and were followed at 6, 12, 24, and 36 months after inclusion. RESULTS: During the study period, 110 patients with intracranial DAVF were screened and 28 patients with Borden type I DAVF were prospectively followed. None of the patients had conversion to higher type of Borden classification or intracranial hemorrhage during follow-up. Five patients showed spontaneous improvement or disappearance of neurological symptoms (5/28, 17.9%), and 5 patients showed a spontaneous decrease or disappearance of shunt flow on imaging during follow-up (5/28, 17.9%). Stenosis or occlusion of the draining sinuses on initial angiography was significantly associated with shunt flow reduction during follow-up (80.0% vs 21.7%, p = 0.02). CONCLUSION: In this 3-year prospective study, patients with Borden type I DAVF showed benign clinical course; none of these patients experienced conversion to higher type of Borden classification or intracranial hemorrhage. The restrictive changes of the draining sinuses at initial diagnosis might be an imaging biomarker for future shunt flow reduction

北陸地区におけるスクリーニング上部消化管内視鏡検査での咽頭観察の現状

[背景・目的] 現在, スクリーニング上部消化管内視鏡検査における咽頭領域の観察が十分に浸透しているとはいい難い状況である. 北陸地区における上部消化管内視鏡での咽頭観察の現状について調査した. [方法] 日本消化器内視鏡学会専門医114名にアンケートを送付し, 回答のあった73名を対象とし調査した. [結果] 咽頭観察を全例に行っている医師は79.5%, スクリーニングに画像強調観察(image-enhanced endoscopy:IEE)を用いた(I群)のは61.6%であった. 観察時間はI群が白色光(W群)と比べ有意に長く(p<0.001), 1年以内の癌の発見率はI群がW群と比べ有意に高かった(p=0.007). 問題点として, 観察の困難さ, 苦痛増強の可能性などの意見が多かった. [結論] スクリーニングにおける咽頭観察において, 癌の発見にはIEEにて時間をかけて観察することが重要である可能性が示唆された. 今後, さらなる咽頭観察の啓蒙活動が重要と考えられる.出版者照会後に全文公

Theoretical quest for photoconversion molecules having opposite directions of the electric dipole moment in S0 and S1 states

Ab initio calculations at the level of CASPT2 with Dunning's correlation consistent cc-pVXZ (X=D, T, Q) basis sets have been carried out for pyrimidine, quinoxaline, phthalazine, and their substituted compounds to find candidates that show a change in the direction of the electric dipole moment for the S0 → S1 transition. The present calculations reveal that 6,7-difluorophthalazine and 6,7-dichlorophthalazine are strong candidates having a large and clear change in the direction of the electric dipole moment on the S0 → S1 transition. © 2009 American Institute of Physics