Updated on 2026/07/28

写真a

 
FUJIWARA Kazuki
 
Organization
Research Field in Medicine and Health Sciences, Medical and Dental Sciences Area Graduate School of Medical and Dental Sciences Advanced Therapeutics Course Sensory Organology Assistant Professor
Title
Assistant Professor
 

Papers

  • Fujiwara K., Yamashita T., Terasaki H., Nakao K., Sakamoto T. .  Quantification of peripapillary nerve fibre elevation and its association with axial length, optic disc tilt, and parapapillary atrophy area in young, healthy eyes .  Eye Basingstoke38 ( 6 ) 1112 - 1117   2024.4Reviewed International journal

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Eye Basingstoke  

    Background: Eyes with peripapillary nerve fibre elevation (pNFE) may have a gap between the optic nerve papillary margin on colour fundus photography and Bruch’s membrane opening on cross-sectional optical coherence tomography (OCT). This study was conducted to evaluate the quantification of the height of pNFE in young healthy eyes and examine the relationship between pNFE height and axial length. Methods: A prospective, observational, cross-sectional study was performed involving 117 right eyes. All participants (mean age 25.8 years) underwent comprehensive ophthalmologic examination involving axial length, fundus photography, and peripapillary and optic disc OCT. pNFE height was defined as the distance between the retinal surface plane and the upper edge of the pNFE in optic disc cross-sectional OCT images. Optic disc tilt was evaluated using a sine curve on retinal nerve fibre layer B-scan images. Parapapillary atrophy (PPA) area in colour fundus images was calculated using ImageJ and corrected using Bennett’s formula. We evaluated relationships between pNFE height, axial length, optic disc papillary tilt, and PPA area using Spearman’s correlation analysis. Results: Sixty-five eyes had pNFE, with a mean pNFE height of 84.7 μm. pNFE height was significantly positively correlated with axial length (r = 0.32, p < 0.001), optic disc tilt (r = 0.25, p = 0.008), and PPA area (r = 0.27, p = 0.004). Conclusions: pNFE is not rare in young healthy eyes. Eyes with higher pNFE had a longer axial length and larger optic disc tilt and PPA area.

    DOI: 10.1038/s41433-023-02827-y

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  • Uto Y., Yamashita T., Fujiwara K., Iwase A., Terasaki H., Nakao K., Sakamoto T. .  Parapapillary choroidal dense pigmentation in young healthy eyes: a cross-sectional study .  International Journal of Retina and Vitreous12 ( 1 )   2026.12Reviewed International journal

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:International Journal of Retina and Vitreous  

    Background: While observing fundus photographs from exploratory research investigating individual differences in the fundus, we discovered a black band around the optic nerve head that had not been reported in previous studies. Such eyes with parapapillary choroidal dense pigmentation (PCP) have a pigmented conus visible on color fundus photography. This study aimed to determine the prevalence of PCP in young healthy eyes and examine its relationships with axial length, optic disc tilt, and conus area. Methods: This prospective, observational, cross-sectional study included the right eyes of 133 participants, who were examined between November 1, 2010 and February 20, 2012. Among them, 117 right eyes of 117 patients were finally analyzed. Participants underwent comprehensive ophthalmologic examinations, including axial length measurement, fundus photography, and optic disc optical coherence tomography (OCT). Based on their color fundus photographs and optic disc cross-sectional OCT images, eyes were categorized into the non-PCP, temporal-PCP, and circum-PCP groups. Optic disc tilt was evaluated using a sine curve based on the retinal nerve fiber layer B-scan images. The conus area in the color fundus images was calculated using ImageJ and corrected using Bennett’s formula. The Steel–Dwass test was used to perform multiple comparisons of the axial length, optic disc tilt, and conus area among the three groups. Results: The mean age and axial length of the participants were 25.8 years and 25.5 mm, respectively. Of the 117 eyes, 49, 17, and 51 had non-PCP, temporal-PCP, and circum-PCP, respectively. The axial length (p = 0.011) and conus area (p = 0.047) were significantly shorter and smaller, respectively, for the circum-PCP group than for the non-PCP group. No significant differences were observed in the other intergroup comparisons. Conclusions: OCT findings revealed that PCP appears black due to choroidal pigment. The eyes with circumferential PCP had shorter axial lengths and smaller conus areas than that of those without, suggesting that it may occur more likely in eyes with less axial elongation.

    DOI: 10.1186/s40942-026-00865-8

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  • Terasaki H., Yamashita T., Funatsu R., Nomoto S., Fujiwara K., Shiihara H., Yamashita T., Sakamoto T. .  Effect of the macular shape on hole findings in idiopathic macular hole differs depending on the stage of the macular hole .  Scientific Reports13 ( 1 ) 15367   2023.12Reviewed International journal

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Scientific Reports  

    This study aimed to investigate the relationship between macular shape and idiopathic macular hole (MH) findings using an objective method. We present retrospective observational case series on patients with MH. The shape of the macular area was quantified using quadratic equations, and the ocular shape (OS) index was calculated. The correlation between the OS index and macular hole findings for each stage was evaluated. Pearson's correlation coefficient showed a significant correlation between the OS index and horizontal hole diameter (p = 0.044), bottom diameter (p = 0.006), and vertical bottom diameter (p = 0.024) in stage 2. For stage 4, there was a negative and significant correlation between the OS index and age (p = 0.037), and horizontal (p = 0.021) and vertical (p = 0.027) bottom diameter. Multiple regression analysis showed that the horizontal (p = 0.0070) and vertical (p = 0.031) bottom diameter and OS index were independently and positively correlated in stage 2. In stage 4, the OS index was independently and negatively correlated with the horizontal (p = 0.037) and vertical (p = 0.048) bottom diameter. The ocular shape of the macula affects MH findings, and its impact depends on its stage.

    DOI: 10.1038/s41598-023-42509-z

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  • 池田 満里, 椎原 秀樹, 藤原 和樹, 田中 実, 山下 高明, 坂本 泰二 .  特集 第76回日本臨床眼科学会講演集[6] 原著 先天網膜分離症に血管新生緑内障を続発した症例 .  臨床眼科77 ( 8 ) 1025 - 1029   2023.8Reviewed

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:株式会社医学書院  

    DOI: 10.11477/mf.1410214881

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  • 池田 満里, 椎原 秀樹, 藤原 和樹, 田中 実, 山下 高明, 坂本 泰二 .  先天網膜分離症に血管新生緑内障を続発した症例 .  臨床眼科77 ( 8 ) 1025 - 1029   2023.8Reviewed

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:(株)医学書院  

    <文献概要>血管新生緑内障を続発した先天網膜分離症の症例を経験したので報告する。症例:症例は46歳,男性。幼少期に先天網膜分離症と診断され,不定期に眼科を受診していた。右眼の視力低下を主訴に近医を受診し,右眼圧が高値であったため鹿児島大学病院眼科を紹介され受診した。初診時視力は右光覚弁,左(0.09),眼圧は右62mmHg,左9mmHgであった。右眼は虹彩新生血管を認め,隅角は全周で虹彩後癒着を認めた。眼底検査では右眼は後極を中心に広範囲で網脈絡膜萎縮を認めたが,網膜出血はなかった。光干渉断層計では,右眼の後極部は網脈絡膜萎縮の状態で網膜分離は認めなかった。左眼はアーケード血管を超える広範囲の後極部に網膜分離を認めた。フルオレセイン蛍光眼底造影では右眼は広範囲の無血管領域と乳頭外網膜新生血管を認めた。左眼には無血管領域はなかった。網膜電図ではb波の減弱を認め,陰性型の異常があった。頭部MRIでは右内頸動脈および眼動脈の狭窄はなかった。以上より先天網膜分離症に合併した,右眼血管新生緑内障と診断した。すでに視力が光覚弁となっており,疼痛の訴えもなかったために治療は行わずに経過観察の方針となり,その後,右眼の光覚は失われたが病態に変化はない。結論:先天網膜分離症は血管新生緑内障を発症することがある。網膜分離が虚血の原因となりえるが,虚血網膜では網膜分離が消失し,網脈絡膜萎縮の状態になることがあり,鑑別には注意を要する。

  • Shiihara H., Sonoda S., Terasaki H., Fujiwara K., Funatsu R., Shiba Y., Kumagai Y., Honda N., Sakamoto T. .  Wayfinding artificial intelligence to detect clinically meaningful spots of retinal diseases: Artificial intelligence to help retina specialists in real world practice .  Plos One18 ( 3 March ) e0283214   2023.3International journal

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Plos One  

    Aim/background To aim of this study is to develop an artificial intelligence (AI) that aids in the thought process by providing retinal clinicians with clinically meaningful or abnormal findings rather than just a final diagnosis, i.e., a “wayfinding AI.” Methods Spectral domain optical coherence tomography B-scan images were classified into 189 normal and 111 diseased eyes. These were automatically segmented using a deep-learning based boundary-layer detection model. During segmentation, the AI model calculates the probability of the boundary surface of the layer for each A-scan. If this probability distribution is not biased toward a single point, layer detection is defined as ambiguous. This ambiguity was calculated using entropy, and a value referred to as the ambiguity index was calculated for each OCT image. The ability of the ambiguity index to classify normal and diseased images and the presence or absence of abnormalities in each layer of the retina were evaluated based on the area under the curve (AUC). A heatmap, i.e., an ambiguity-map, of each layer, that changes the color according to the ambiguity index value, was also created. Results The ambiguity index of the overall retina of the normal and disease-affected images (mean ± SD) were 1.76 ± 0.10 and 2.06 ± 0.22, respectively, with a significant difference (p < 0.05). The AUC used to distinguish normal and disease-affected images using the ambiguity index was 0.93, and was 0.588 for the internal limiting membrane boundary, 0.902 for the nerve fiber layer/ganglion cell layer boundary, 0.920 for the inner plexiform layer/inner nuclear layer boundary, 0.882 for the outer plexiform layer/outer nuclear layer boundary, 0.926 for the ellipsoid zone line, and 0.866 for the retinal pigment epithelium/Bruch's membrane boundary. Three representative cases reveal the usefulness of an ambiguity map. Conclusions The present AI algorithm can pinpoint abnormal retinal lesions in OCT images, and its localization is known at a glance when using an ambiguity map. This will help diagnose the processes of clinicians as a wayfinding tool.

    DOI: 10.1371/journal.pone.0283214

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  • 藤原 和樹, 寺崎 寛人, 古江 恵理, 椎原 秀樹, 大井 城一郎, 青木 恵美, 園田 祥三, 坂本 泰二 .  臨床報告 悪性黒色腫に対するダブラフェニブ・トラメチニブ併用療法中に脈絡膜新生血管を生じた1例 .  臨床眼科76 ( 10 ) 1372 - 1379   2022.10Reviewed

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:株式会社医学書院  

    DOI: 10.11477/mf.1410214526

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  • 藤原 和樹, 寺崎 寛人, 古江 恵理, 椎原 秀樹, 大井 城一郎, 青木 恵美, 園田 祥三, 坂本 泰二 .  悪性黒色腫に対するダブラフェニブ・トラメチニブ併用療法中に脈絡膜新生血管を生じた1例 .  臨床眼科76 ( 10 ) 1372 - 1379   2022.10Reviewed

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:(株)医学書院  

    <文献概要>目的:BRAF阻害薬のダブラフェニブメシル塩酸塩とMEK阻害薬のトラメチニブジメチルスルホキシド付加物の併用療法による加療中に脈絡膜新生血管(CNV)を発症した1例を経験したので報告する。症例:52歳,女性。右下肢原発の悪性黒色腫に対して皮膚科で治療中であった。ダブラフェニブ・トラメチニブ併用療法の開始後から左眼の視力低下を自覚し,鹿児島大学病院眼科を受診した。視力は右(1.0),左(0.1)であった。両眼の眼底に斑状の白色病変を多数認め,左眼黄斑部には網膜下に白色の斑状病巣を伴う漿液性網膜剥離,網膜出血を認めた。光干渉断層計では,左網膜下にフィブリン,網膜下高輝度物質を伴う漿液性網膜剥離,網膜内浮腫を認めた。インドシアニングリーン蛍光眼底造影検査では両眼とも斑状の低蛍光が多発していたが,フィブリンによる蛍光ブロックのためCNVは指摘できなかった。フルオレセイン蛍光眼底造影検査では左眼にclassic CNVパターンを認めた。光干渉断層血管撮影では左黄斑部鼻側にCNVを認めた。以上の所見から,ダブラフェニブ・トラメチニブ併用療法中に併発したCNVと診断した。抗血管内皮増殖因子(VEGF)療法を複数回行ったところ,滲出性変化は消失し,視力の改善を認めた。結論:悪性黒色腫に対してダブラフェニブ・トラメチニブ併用療法での加療中に稀にCNVを発症することがある。本症例は抗VEGF薬による治療に良好な反応性を示した。

  • Yamashita T., Shiihara H., Terasaki H., Fujiwara K., Tanaka M., Sakamoto T. .  Characteristics of pigmentary glaucoma in Japanese individuals .  Plos One17 ( 6 June ) e0268864   2022.6Reviewed International journal

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    Purpose Myopia is a known risk factor of pigmentary glaucoma (PG), and the increased prevalence of myopia in Asian countries indicates that more cases of PG will likely develop soon. However, there are no diagnostic criteria for PG for Asians. Therefore, the purpose of this study is to determine the characteristics of PG in Japanese individuals and establish three diagnostic signs for PG. Methods This was a single-center, retrospective, case series study of glaucoma patients who visited the Kagoshima University Hospital between January 2015 and January 2020. The inclusion criteria were age <50 years at time of diagnosis and presence of pigmentation in the anterior chamber (AC) angle including a Sampaolesi line. Eyes with pigmentation of the AC angle caused by other types of glaucoma such as uveitis, trauma, exfoliation, or childhood glaucoma were excluded. We investigated the classic diagnostic triad of signs of PG; posterior corneal pigmentation, mid peripheral iris transillumination defect, and pigmentation of the trabecular meshwork. We also examined the Sampaolesi line, iris concavity, and midperipheral iris depigmentation in eyes with PG. Results Ten eyes of 5 Japanese men and 10 eyes of 5 Japanese women were studied. Their age ranged from 13 to 46 years at the time of diagnosis. One eye had posterior corneal pigmentation and 6 eyes had pigmentation of the trabecular meshwork. None had mid peripheral iris transillumination defect. The Sampaolesi line, iris concavity, and midperipheral iris depigmentation were found in all patients except one patient who lacked the mid peripheral depigmentation. Two eyes had the pigment reversal sign, none had lens pigmentation, and 2 eyes had peripheral retinal degeneration. Conclusion The presence of the Sampaolesi line, iris concavity, and midperipheral iris depigmentation may be appropriate signs for the diagnosis of PG in Asians.

    DOI: 10.1371/journal.pone.0268864

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  • Uemura A., Arimura N., Yamakiri K., Fujiwara K., Furue E., Sakamoto T. .  Macular holes following vitrectomy for rhegmatogenous retinal detachment: epiretinal proliferation and spontaneous closure of macular holes .  Graefe S Archive for Clinical and Experimental Ophthalmology259 ( 8 ) 2235 - 2241   2021.8Reviewed International journal

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Graefe S Archive for Clinical and Experimental Ophthalmology  

    Purpose: To describe the characteristics and management of full-thickness macular holes (MHs) that develop after pars plana vitrectomy for rhegmatogenous retinal detachment (RD). Methods: Retrospective, interventional, consecutive case series. Patients who developed secondary full-thickness MHs after prior pars plana vitrectomy for RD over a 6-year period were included. The main outcome measures included optical coherence tomography (OCT) findings and the clinical course of full-thickness MHs. Results: A total of 11 eyes of 11 consecutive patients were included in the study. The mean age of the patients was 58.8 years (range, 47–70 years). The median time between RD repair and MH diagnosis was 36 months (range, 1 month–11 years). The fovea was attached to 10 eyes (91%) at the time of RD repair. OCT demonstrated epiretinal proliferation (EP) at the hole margin in 10 eyes (91%). MH spontaneously closed in 7 eyes (63%) but reopened in 5 eyes. A total of 7 eyes (63%) required a vitrectomy to repair the MHs. All MHs were closed at the last follow-up visit. Conclusion: Full-thickness MHs after pars plana vitrectomy for RD have features that are distinct from that of typical idiopathic MH. The presence of EPs is common, and MHs are prone to spontaneous closure and reopening. These findings suggest that EP may be associated with spontaneous hole closure and that long-term follow-up is necessary even if the MHs close spontaneously.

    DOI: 10.1007/s00417-021-05183-3

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  • 網膜研究とデータサイエンス Reviewed

    坂本 泰二, 園田 祥三, 山下 高明, 山下 敏史, 寺崎 寛人, 椎原 秀樹, 船津 諒, 山切 啓太, 内野 英輔, 中尾 久美子, 田中 実, 齋藤 司朗, 上笹 貫太郎, 吉永 就正, 鮫島 誠治, 大井 城一郎, 白澤 誠, 中澤 祐則, 椎原 紗圭, 藤原 和樹, 迫野 能士, 宇辰 賢祐, 三宅 ゆりな, 宇都 勇紀, 町田 碧, 山下 眞弘, 冨田 将利, 鈴木 敬久, 高野 友香, 豊留 貴久子, 熊迫 奏泉, 柳田 豊子, 大久保 明子, 土居 範仁, 木村 勝哲, 平瀬 純伸, 松尾 由紀子, あべ松 徳子, 尾辻 太, 芳原 直也, 柿内 奈保子, 古江 惠理, 松下 裕亮, 山藤 香子, 三原 直久, 市來 美沙紀, 北國 陽, 濱田 拓人, 本瀬 泰良, 池田 満里, 野元 翔平, 林 葵子, 三宅 頌己, 朝岡 亮, 北野 滋彦, 志村 雅彦, 本多 直人, 柴 涼介, 熊谷 佳紀, 坂下 祐輔, 小沢 素生, 田邉 泰士, 廣川 真梨子, 矢成 光弘, 吉 媛テイ, 葛西 洋志, 藤原 朋春, 秋葉 正博, 相見 太樹, 安 光州, 横田 秀夫, 堀江 寿雲, 木倉 龍, 岩瀬 好彦, 篠原 祐樹, 園田 真也

    日本眼科学会雑誌   126 ( 3 )   221 - 253   2022.3

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    Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)   Publisher:(公財)日本眼科学会  

    データサイエンスはデータ解析を行う学問であるが,この状況が近年劇的に変化してきている.人工知能(AI),第5世代(5G)通信ネットワーク,モノのインターネット(IoT)などが社会実装され,社会を一気に変えつつある.この変化は医療においてはデジタル医療革命と呼ばれ,世界中に広がりつつある.この変化に対する我々の研究を紹介する.I.画像解析におけるAIの可能性 眼科は診療や研究に画像を用いることが多いが,客観性や定量性が不十分であったので,AIを導入して客観性や定量性のある画像解析を研究した.脈絡膜の光干渉断層計(OCT)en face画像について層別化を試みた.support vector machine(SVM)を用いたAIにより脈絡膜en face画像を層判別するアルゴリズムを開発した.学習用データの各特徴量からSVMモデルを作成し,検証用データを用いて,脈絡膜の各層に対する決定係数を算出した.その結果,決定係数は平均0.985であった.このことは,これまで定性的にしか区別できなかった画像をAIにより客観的かつ高い再現性を持って分類できることを示すものである.また,同法で得られたen face画像について,脈絡膜血管走行のパターン分類を行った.中心性漿液性脈絡網膜症(CSC)を対象としてen face画像を取得し,血管面積,血管長と平均血管径を定量し,正対称方向に走行する血管割合(symmetry index)を算出した.その結果,CSC眼ではHaller層血管が拡張しているだけでなく,上下で非対称性の走行を取っていた.この構造的差異は疾患眼だけではなく僚眼にもみられたので,CSCにおける先天性素因の存在を確認することができた.正常眼の黄斑直下の脈絡膜には太いHaller層血管が存在しないため血管が拡張しても黄斑部への影響は少ないが,CSC眼では非対称性にHaller層血管が走行するため,Haller層血管が拡張すると黄斑下の脈絡膜内層が圧排され,血液網膜関門が破綻して,滲出液が網膜下に貯留するのがCSCであると考える.II.AIによる新しい研究テーマの創出 眼底所見から性別判定が可能であることをAIは証明したが,その証明過程は不明である.そこで眼底写真に関連する定量化された蓄積データを集め,それらのみで性別を予測できるか否かについて調べた.その結果,約80%の確率で眼底から性別を予測できた.女性の眼底は男性よりも緑色が強く,上耳側動脈が黄斑の近くを走行するなどの特徴があった.それらが何を反映しているかを研究したところ,生下時に60%程度は男女差の特徴がすでに備わっており,第二次性徴を過ぎてそれが80%に増加することが分かった.人間が思いもつかなかった現象や事実をAIが発見して,それを人間が研究したという事実は,眼科研究史的にも大きな意味を持つ.今後は研究テーマの発掘もAIが中心となるかもしれない.III.ビッグデータの重要性 ビッグデータこそが今後の眼科におけるデータサイエンスの中心である.日本網膜硝子体学会(JRVS)は,2016年にJRVS理事施設で施行された全網膜剥離手術症例について登録し,3,446例が集積された(J-RDレジストリ).さまざまな解析が行われ,経毛様体扁平部硝子体切除術と強膜内陥術を選ぶ術者の傾向,視力変化,剥離部位による手術成功率の差など,2016年時点の日本の網膜剥離についての基礎データが完成した.さらに傾向スコアマッチングを用いてこのデータを解析したところ,シリコーンオイルタンポナーデがガスタンポナーデよりも網膜障害が強いこと,内的網膜下液ドレナージは術後に網膜前膜を生じやすいというエビデンスなどが得られた.ほかにも,治療における男女差など現在も多くの知見が得られ続けている.ビッグデータは今後の眼科医療を正しく進めるうえで重要なものである.しかし,日本はその点で立ち遅れており,その早期の確立が必要である.(著者抄録)

Presentations

  • 藤原 和樹, 山下 高明, 朝岡 亮, 岩瀬 愛子, 坂本 泰二, 酒井 寛, 新家 眞   久米島スタディ健常眼の上下耳側の血管角度と眼軸長との関連  

    日本緑内障学会抄録集  2021.9  日本緑内障学会

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    Language:Japanese   Presentation type:Oral presentation (general)