Long-range order parameter of single L1₀-FePd nanoparticle determined by nanobeam electron diffraction: Particle size dependence of the order parameter

The long-range order (LRO) parameter (S) of single isolated L 10 -FePd nanoparticle was determined by quantitative analysis of nanobeam electron diffraction (NBD) intensities and intensity calculations considering the multiple scattering of electrons. The obtained order parameters of the nanoparticles larger than 8 nm are distributed around the mean LRO parameter (S- =0.79) which was determined by selected area electron diffraction intensity analysis, while the parameters slightly decreased gradually as the particle size decreased below about 8 nm (S=0.60-0.73). The low degree of order in very small particles is responsible for the coercivity decrease of the L 10 nanoparticles in smaller-sized regions. Quantitative NBD intensity analysis is quite useful for the determination of the LRO parameter of individual L 10 -FePd single crystalline nanoparticle. Experimental conditions required for NBD analysis are presented in detail and the possible experimental errors of the determined LRO parameters are discussed. © 2005 American Institute of Physics.Kazuhisa Sato, Yoshihiko Hirotsu and Hirotaro Mori, "Long-range order parameter of single L1₀-FePd nanoparticle determined by nanobeam electron diffraction: Particle size dependence of the order parameter", Journal of Applied Physics 98, 024308 (2005) https://doi.org/10.1063/1.1985973

Determination of order parameter of L1₀ -FePd nanoparticles by electron diffraction

Long-range order (LRO) parameters of two-dimensional dispersed single-crystalline 10-nm -sized FePd nanoparticles with the L 10 structure have been determined accurately by electron diffraction in transmission electron microscopes (TEMs) under accelerating voltages of 300 kV and 1 kV. Diffraction patterns by exciting hh0 systematic reflections effectively reduced the numbers of diffracted beams and simplified the thickness dependence of intensity ratio I110 I220 for 110 and 220 reflections. Mean thickness of the nanoparticles was estimated to be 7.8 nm by electron holography. The relation between the intensity ratio and the order parameter was calculated on the basis of multiple-scattering intensity calculation. By comparing the relation and experimentally obtained intensity ratios, the order parameters of 0.65 and 0.79 were obtained using 300-kV TEM for FePd nanoparticles after annealing at 873 K for 3.6 and 36 ks, respectively. Also, the order parameter of 0.82 was obtained using 1-MV TEM for the same specimen annealed at 873 K for 36 ks. These order parameters were determined using the Debye-Waller factors for bulk Fe and Pd. The order parameter decreased about 7.3% when a very large Debye-Waller factor as large as 0.01 nm2 was assumed. A combination of electron diffraction under the conditions of hh0 systematic reflections and the diffraction experiment at the high accelerating voltage makes the LRO parameter analysis easy and correct. © 2005 American Institute of Physics.Kazuhisa Sato, Yoshihiko Hirotsu and Hirotaro Mori, "Determination of order parameter of L1₀–FePd nanoparticles by electron diffraction", Journal of Applied Physics 97, 084301 (2005) https://doi.org/10.1063/1.186198

Design and Development of Mapping Exercise between Concept Map and Image Figure

概念マップを命題単位でイメージ図と対応付ける学習活動として，(1) イメージ図選択活動と(2) イメージ図組立活動，の二つの活動を演習として実現するソフトウェアシステムを設計・開発し，小学校理科での授業実践を通して評価した．概念間の関係として表現されている概念マップを視覚的な意味をもった構成要素とその空間配置として表現されたイメージ図と対応付けることは，知識の精緻化の一つとなりえる．正誤判定を伴ってこの対応付けを実現するためには，概念マップが命題レベルで正誤判定されている必要があるが，このためにキットビルド概念マップを用いている．授業実践を通して，この対応付け演習が児童及び教諭に有用な学習活動と認識されたこと，対象課題についての理解促進に貢献すること，を示唆する結果が得られた

Differentiation of carcinosarcoma from endometrial carcinoma on magnetic resonance imaging using deep learning

Purpose: To verify whether deep learning can be used to differentiate between carcinosarcomas (CSs) and endometrial carcinomas (ECs) using several magnetic resonance imaging (MRI) sequences. Material and methods: This retrospective study included 52 patients with CS and 279 patients with EC. A deep-learning model that uses convolutional neural networks (CNN) was trained with 572 T2-weighted images (T2WI) from 42 patients, 488 apparent diffusion coefficient of water maps from 33 patients, and 539 fat-saturated contrast-enhanced T1-weighted images from 40 patients with CS, as well as 1612 images from 223 patients with EC for each sequence. These were tested with 9-10 images of 9-10 patients with CS and 56 images of 56 patients with EC for each sequence, respectively. Three experienced radiologists independently interpreted these test images. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) for each sequence were compared between the CNN models and the radiologists. Results: The CNN model of each sequence had sensitivity 0.89-0.93, specificity 0.44-0.70, accuracy 0.83-0.89, and AUC 0.80-0.94. It also showed an equivalent or better diagnostic performance than the 3 readers (sensitivity 0.43-0.91, specificity 0.30-0.78, accuracy 0.45-0.88, and AUC 0.49-0.92). The CNN model displayed the highest diagnostic performance on T2WI (sensitivity 0.93, specificity 0.70, accuracy 0.89, and AUC 0.94). Conclusions: Deep learning provided diagnostic performance comparable to or better than experienced radiologists when distinguishing between CS and EC on MRI

TRPC6 regulates phenotypic switching of vascular smooth muscle cells through plasma membrane potential-dependent coupling with PTEN

Vascular smooth muscle cells (VSMCs) play critical roles in the stability and tonic regulation of vascular homeostasis. VSMCs can switch back and forth between highly proliferative synthetic and fully differentiated contractile phenotypes in response to changes in the vessel environment. Although abnormal phenotypic switching of VSMCs is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty, how control of VSMC phenotypic switching is dysregulated in pathologic conditions remains obscure. We found that inhibition of canonical transient receptor potential 6 (TRPC6) channels facilitated contractile differentiation of VSMCs through plasma membrane hyperpolarization. TRPC6-deficient VSMCs exhibited more polarized resting membrane potentials and higher protein kinase B (Akt) activity than wild-type VSMCs in response to TGF-β1 stimulation. Ischemic stress elicited by oxygen-glucose deprivation suppressed TGF-β1-induced hyperpolarization and VSMC differentiation, but this effect was abolished by TRPC6 deletion. TRPC6-mediated Ca2+ influx and depolarization coordinately promoted the interaction of TRPC6 with lipid phosphatase and tensin homolog deleted from chromosome 10 (PTEN), a negative regulator of Akt activation. Given the marked up-regulation of TRPC6 observed in vascular disorders, our findings suggest that attenuation of TRPC6 channel activity in pathologic VSMCs could be a rational strategy to maintain vascular quality control by fine-tuning of VSMC phenotypic switching.Fil: Numaga-Tomita, Takuro. No especifíca;Fil: Shimauchi, Tsukasa. Kyushu University; JapónFil: Oda, Sayaka. No especifíca;Fil: Tanaka, Tomohiro. No especifíca;Fil: Nishiyama, Kazuhiro. Kyushu University; JapónFil: Nishimura, Akiyuki. Kyushu University; JapónFil: Birnbaumer, Lutz. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mori, Yasuo. No especifíca;Fil: Nishida, Motohiro. Kyushu University; Japó

<症例>胃癌手術 (脾摘術合併胃全摘術) 後の門脈血栓症の1例

A 48-year-old woman underwent total gastrectomy, splenectomy, and distal pancreatectomy with en bloc regional lymph node dissection for gastric carcinoma. Dull pain in the right upper quadrant and the back developed postoperatively. Contrast-enhanced computed tomography and ultrasonography disclosed portal vein thrombosis (PVT). Heparin and urokinase were given in conjunction with antbiotics. This treatment resulted in clinical improvement, but failed to achieve complete thrombolysis. Cavernous transformation of the portal system was confirmed. Although PVT after splenectomy has been reported mainly in patients with hematological disorders, our case suggests that splenectomy for en bloc node dissection in gastric carcinoma is a possible cause of PVT.門脈血栓症は肝硬変や肝癌の患者で時に認められる病態であるが, 術後の門脈血栓症は稀であり, そのほとんどが脾腫に対する脾摘術後に発生している. 我々は胃癌根治術に伴う脾摘術後に門脈血栓をきたした症例を経験したので報告する. 症例は48才の女性で, 胃体上部後壁を中心とする5型胃癌に対し, 胃全摘術, 脾摘術, 膵尾側切除術を行なった. 病変は組織学的には低分化腺癌, 深達度ss, No, Po, Ho の stage I b で, 摘出した脾重量は 150g であった. なお, 術前の出血凝固系検査には異常を認めなかった. 術後18日目より右上腹部から背部の鈍痛が出現し, 白血球数, CRP, 血清アルカリフォスファターゼ値も上昇してきた. 術後19日目の造影CTで, 門脈, 上腸間膜静脈がほとんど造影されず, 門脈から上腸間膜静脈におよぶ血栓形成が考えられた. 抗生剤の投与とともにただちにへパリンの持続静注とウロキナーゼ投与を併用したところ, 臨床症状や検査所見は軽快した. ただし, 血栓は完全に消失せず, その後の腹部血管造影では側副血行路としての肝十二指腸間膜内の静脈拡張, いわゆるcavernous transformation が認められた. へパリン, ウロキナーゼの投与からワーファリン内服に切り替え, 患者は術後66日目に退院した. 現在, 術後2年経過したが, 食道静脈瘤の出現や消化管出血などの門脈血栓, 門脈圧充亢進に起因すると思われる症状は認めていない. 我々の症例は, 進行胃癌根治術の際にしばしは合わせ行われる脾摘術後にも門脈血栓症の出現する可能性があることを示唆しており, そのような手術を受けた患者が術後原因不明の腹部症状や白血球増加を来たした時には門脈血栓症も疑い精査を進める必要があると考えられる