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A Study on the development of a workflow-supporting system of cardiac X-ray computed tomography image analysis for the diagnosis and treatment of pediatric cardiac malformation
Get PDF新潟大学Niigata University博士（保健学）新大院博(保)第51
西南日本弧富山堆積盆に分布する漸新世～中新世火山岩類の地質学的および岩石学的研究 : 日本海拡大期の沈み込み帯火山活動の時間変遷
Get PDF新潟大学Niigata University博士（理学）The present study aims to investigate the role of igneous activity associated with back-arc spreading in modern plate tectonics, which is considered to have started in 1.0 Ga. In this study, the author focuses on the Japan Sea opening, which is a typical back arc spreading, and conduct geological and petrological studies of volcanic rocks distributed in the Toyama Basin of the southwest Japan arc during the Japan Sea opening (Oligocene to Miocene) in order to clarify the time evolution of subduction zone volcanism and its role during the spreading. Strata related to the Japan Sea opening distributed in the Toyama Basin are subdivided into the Nanto Group (Johana and Nirehara Formations) and the Yatsuo Group (Iwaine Formation, Iozen Formation, and the other eight formations). Lithofacies formed on land (e.g., lava, pyroclastic flow deposit and debris flow deposit) and in shallow marine (e.g., inner bay and shallow water deposits) to deep marine environment (e.g., turbidite) were found from the strata. Zircon U-Pb ages of 22.8 ± 0.2 Ma, 23.6 ± 0.3 Ma, 17.1 ± 0.4 Ma, and 16.8 ± 0.2 Ma were obtained from the Johana, Nirehara, Iwaine and Iozen Formations. The following geotectonic history of the Toyama basin is considered, based on the lithology and the ages of each formation. The Toyama Basin was formed by deposition of non-marine to shallow marine strata and rhyolitic pyroclastic flows at about 23 Ma, followed by andesitic volcanism (non-marine to shallow marine) at 18-17 Ma and dacite to rhyolitic volcanism (non-marine to shallow marine) at 17-16 Ma. The sedimentary environment is considered to have changed to deep marine by around 15 Ma. Among the strata that have been geologically examined above, the volcanic rocks collected from the Johana, Iwaine and Iozen Formations in the Nanto area were examined for their petrogenesis. Based on petrography, the volcanic rocks of each formation are classified into one type for the Johana Formation (Jh-Pyr), three types for the Iwaine Formation (Iw-OlPx, Iw-Amp and Iw-Px) and one type for the Iozen Formation (Io-Aph). Based on the major and trace element compositions, Sr-Nd isotopes, and zircon trace element compositions, the following petrogenesis of the volcanic rocks is considered. Although Jh-Pyr and Io-Aph have different K2O contents, they show similar trace element trends. The involvement of crustal melting to produce those rhyolitic magma was inferred from enriched light rare earth elements (LREE), Nb-Ta depletion, steeply positive trend in La-La/Yb diagram, low Cr and Ni concentrations, enriched Sr-Nd isotope, and enriched zircon trace element composition. Iw-OlPx has a maximum Mg# of 65, suggesting that it was formed by the partial melting of mantle hydrous with slab-derived fluids. Iw-Amp is characterized by, for instance, high Sr/Y ratio and considered as results of partial melting of mantle metasomatized by adakite melt. Iw-Px can be explained by differentiation of basaltic magma, based on the trend of compositional variation diagrams, however it is thought to assimilate the crust because of its highly enriched Sr-Nd isotopic composition. The mantle wedge is thought to have been relatively hot during the Japan Sea opening, when such geochemically various volcanic rocks were formed. It is estimated that the old and cold Pacific Plate was subducting into the southwest Japan arc at that time. Therefore, an event that maintains the mantle wedge in a high-temperature state, such as upwelling of the asthenospheric mantle into the mantle wedge, is necessary to generate large-scale andesitic volcanism. Because rhyolitic magmatism of the Johana and Iozen Formations accompanies basaltic to andesitic volcanism, the basaltic to andesitic volcanism is considered to have played a role as heat source. Jh-Pyr and Io-Aph have more enriched whole-rock Sr-Nd isotope and zircon Hf isotope than the Hida belt, suggesting that old continental crust such as the North and South China Craton involved the genesis of the rhyolites. Trace element compositions of rhyolites from the Johana and Iozen Formations are similar to those of the upper crust. Rhyolites distributed in the rift zone of the subduction zone also show similar trends. This indicates that felsic magmatism related to rifting in the subduction zone, such as back-arc spreading, contributes to recycling of crustal materials in the continental crust that the new upper crust is generated by crustal melting.1.0Gaに始まったと考えられている現在のプレートテクトニクスの中でも、背弧拡大に伴う火成活動はその原因やプレートテクトニクスでの役割に関して、未だ多くの未解明な点がある。本研究では背弧拡大の典型例の一つとされている日本海拡大に注目し、背弧拡大中の沈み込み帯火山活動の時間変遷とその役割を明らかにするため、西南日本弧富山堆積盆に分布する日本海拡大期(漸新世～中新世)火山岩類の地質学的および岩石学的研究を行った。富山堆積盆に分布する日本海拡大期層は下位より、南砺層群(城端層，楡原層)と八尾層群(岩稲層，医王山層，他8層)に区分される。これらの地層から陸上環境を示す岩相(溶岩、火砕流堆積物、河川成堆積物など)や浅海環境(内湾堆積物、浅海成堆積物など)〜深海環境(タービダイトなど)を示す岩相が見出された。城端層、楡原層、岩稲層、医王山層からは22.8±0.2Ma、23.6±0.3Ma、17.1±0.4Ma、16.8±0.2MaのジルコンU-Pb年代を得た。各層の岩相と年代値から、以下の地質学的変遷が考えられる。富山堆積盆は約23Maに陸成層～浅海成層および流紋岩質火砕流の堆積によって形成が開始し、18-17Maの安山岩質火山活動(陸上～浅海)と17-16Maのデイサイト～流紋岩質火山活動(陸上～浅海)を経て、15Ma頃までに堆積環境が深海へと変化した。上記の地質学的検討がなされた地層のうち、南砺地域の城端層、岩稲層、医王山層から採取した火山岩類について、その岩石成因を検討した。岩石記載に基づくと、各層の火山岩類は城端層が1タイプ(Jh-Pyr)、岩稲層が3タイプ(Iw-OlPx、Iw-Amp、Iw-Px)、医王山層(Io-Aph)が1タイプに分類される、全岩主要・微量元素組成、全岩Sr-Nd同位体比組成、ジルコン微量元素組成から、以下のような成因が考えられた。Jh-PyrとIo-Aphは異なるK2O量などをもつが、微量元素の傾向などは類似している。両層の流紋岩はともに、肥沃的なLREE，Nb・Taの負異常、低いCr・Ni量、肥沃的なSr-Nd同位体比組成、肥沃的なジルコン微量元素組成を示し、これは地殻の溶融によって流紋岩が形成されたことを示唆する。Iw-OlPxは最大Mg#が65に達する高マグネシア安山岩で、スラブ由来の流体で汚染されたマントルの部分溶融によって形成されたと考えられる。一方、Iw-Ampはその特徴的な微量化学組成(例えば高Sr/Y比)から、スラブ由来のアダカイトメルトに汚染されたマントルの部分溶融で形成されたと考えられる。Iw-Pxは、その主成分元素組成などの特徴は玄武岩マグマからの結晶分化作用で説明できるものの、Sr-Nd同位体比組成は非常に肥沃的であることから，結晶分化作用と同時に地殻の同化作用が生じていた可能性が示唆される。このような多様な火山岩が形成された日本海拡大期のマントルは高温であったと考えられるが、当時の西南日本弧には古く冷たい太平洋プレートが沈み込んでいたと推定されている。よって、大規模な安山岩質の火山活動を発生させるためにはアセノスフェリックマントルのマントルウェッジへの湧昇のようなマントルウェッジを高温状態にする現象が必要である。城端層と医王山層の流紋岩類は玄武岩～安山岩質火山活動を伴うことから、それらが熱源となり地殻が部分溶融を起こしたと考えられる。これら流紋岩類は基盤岩の飛騨帯よりも肥沃的なSr-Nd同位体比組成、ジルコンHf同位体比組成を持つことから、さらに古い大陸地殻(南北中国地塊?)を起源とする可能性がある。また、流紋岩類の微量元素組成は上部地殻平均化学組成に類似し、沈み込み帯にあるリフト帯で活動する流紋岩と同様の化学的特徴を示す。このことは、背弧拡大のような沈み込み帯におけるリフティングに伴う珪長質火成活動が、地殻の部分溶融によって引き起こされる上部地殻の生成という地殻内での物質循環に寄与していることを示している。新大院博(理)第488
Relation between Intra- and Extra-Tumoral Vascular Invation and Lymph Node Metastasis of pT1 (SM) colorectal carcinoma.
Get PDF新潟大学Niigata University博士（医学）脈管侵襲は病理組織学的リンパ節転移リスク因子であり，内視鏡的完全切除pT1(SM)癌の病理組織学的検索で脈管侵襲が陽性であれば，追加腸切除が考慮される．これまで，脈管侵襲はHE染色標本を用い，腫瘍外間質を対象に評価されてきた．他方，近年では脈管侵襲判定の診断精度と客観性を向上させるため，特殊染色の併用が推奨されている．特殊染色によりこれまで評価対象とされてこなかった腫瘍内脈管侵襲も同定される可能性があるが，大腸pT1(SM)癌で，腫瘍内脈管侵襲がリンパ節転移リスク因子であるかどうかは明らかにはされていない．本研究では，リンパ節郭清がなされた外科切除大腸pT1(SM)癌313例を対象に，特殊染色標本により同定される脈管侵襲を腫瘍内・外とに分け，腫瘍内脈管侵襲がリンパ節転移と関連しているかどうかを検討した．また，病理組織学的検索として，組織型，SM浸潤距離，簇出を評価した．リンパ管侵襲(Ly)は，癌細胞を同定するCAM5.2とリンパ管内皮を同定するD2-40の二重免疫染色により評価した．静脈侵襲(V)は，血管弾性線維を染色するVictoria blue(VB)弾性線維染色により評価した．他の病理組織学的はHE染色標本で評価した．CAM5.2/D2-40二重免疫染色で同定されたリンパ管侵襲(Ly)陽性頻度は，腫瘍外が63.3%，腫瘍内が40.9%，VB弾性線維染色で同定された静脈侵襲(V)陽性頻度は，腫瘍外が27.8%，腫瘍内が5.8%であった．単変量解析では，簇出，腫瘍内Ly，腫瘍外Lyの3因子がリンパ節転移と有意に相関していた(P=0.0004, 0.003, 0.001)が，多変量解析では腫瘍内Lyは有意差はなく，簇出と腫瘍外Lyのみが独立したリンパ節転移リスク因子であった(P=0.040, 0.049)．以上のことから，腫瘍内にもLy, Vは存在するものの，いずれも独立したリンパ節転移リスク因子ではないこと，HE染色標本に特殊染色を併用して内視鏡的完全切除大腸pT1(SM)癌の治療方針を決定する際には，腫瘍外Ly陽性のみが有用な所見であり，腫瘍内Ly陽性およびV陽性は，追加腸切除考慮因子とはならない可能性があることが考えられた．新大院博(医)第1098
口蓋裂幅と中耳炎の関係についての検討
Get PDF新潟大学Niigata University博士（医学）Objectives: To investigate the relationship between cleft width and otitis media (OM) and to determine whether a wide cleft palate (CP) is a risk factor of the incidence, type, amount of middle ear effusion, and prolonged morbidity in OM. Study Design: Retrospective cohort study. Methods: Children with CP who underwent palatoplasty between 2014 and 2018 were analyzed. Cleft width was measured at palatoplasty. The incidence of otitis media with effusion (OME) and acute otitis media (AOM), the type and amount of middle ear effusion, and OME duration and age at resolution were assessed in relation to cleft width. Results: One hundred eighteen children were included. The CP types were Veau I in 16, II in 35, III in 48, and IV in 19 patients. The incidence of OME and AOM before palatoplasty was 83.1% and 49.2%, respectively. Cleft width did not differ significantly between patients with or without OME but was significantly greater in those with, than in those without, AOM (p<.001), in those with mucoid, than in those with serous, effusion (p=.012), and in those with complete, than in those with partial, effusion (p=.01). Regardless of cleft width or type, OME persisted for a median duration of 50 months. Conclusions: Cleft width was significantly associated with the incidence of AOM and the type and amount of middle ear effusion before palatoplasty. However, it was not significantly related to the incidence, age at resolution, or duration of OME. Regardless of cleft width or type, OM in children with CP requires long-term follow-up.Laryngoscope Investigative Otolaryngology. 2022, 7(6), 2126-2132.新大院博(医)第1116
A study on application of deep learning technology in volumetric breast density measurement
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偏微分方程式の有限要素解に対するHypercircle法に基づく局所誤差評価法
Get PDF新潟大学Niigata University博士（理学）High-precision numerical methods are required to solve differential equations that govern physical models for measurement problems appearing in the semiconductor industry, in order to provide reliable and accurate measurement results. In the field of numerical analysis, recent studies are concerning on methods that provide guaranteed error estimation for numerical results obtained by finite element methods (FEM). In particular, Kikuchi and Liu have proposed the hypercircle based a posteriori and a priori error estimation. As required by the four-probe method for resistivity measurement, the local error estimation for FEM solutions of Poisson equations plays an important role in improving the precision of the measurement results. This study aims to extend the hypercircle method to estimate local errors for boundary value problems of the Poisson equation. Meanwhile, the application of the hypercircle method to the error estimation theory for the non-homogeneous Neumann boundary value problems of the modified Helmholtz equation is considered.新大院博(理)第484