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Functional status and left ventricular function in adolescents and adults before surgical closure of secundum atrial septal defects: comparison with patients before device closure.
Get PDF秋田大学博士（医学
ハイパーサーミアのためのワイヤレス温度計測・誘導加熱システムの開発と評価に関する研究～感温磁性体の温度検知および加温可能距離の検証～
Get PDF秋田大学博士（工学）我が国における悪性新生物による死亡者数は，1981年以降増加の一途をたどっている．通常，肺癌などの末期癌患者には，抗がん剤治療，放射線治療および免疫療法が治療法として選択されるが，これらの手法には副作用を伴うことや患者への奏効率が低いことが報告されている．この欠点を低減し，末期癌患者のQOLを向上する手法として，ハイパーサーミアが注目されている．これは，癌細胞が43～45℃程度で加温されることで抗腫瘍効果を増強する特徴を利用した治療法である．さらに，放射線療法との併用において高い局所腫瘍制御が得られ，抗がん剤治療との併用において効果持続期間を延長させ，両者ともに副作用を増大させることなく対腫瘍効果を増大させる報告がされている．現在，ハイパーサーミアの主要な手法としては誘電加熱法が採用されているが，患部をピンポイントに加温することが困難な点および治療部の温度測定のための温度センサの刺入が欠点としてあげられている．そこで，松木氏らが提唱した埋め込み式ハイパーサーミアに類する「ソフトヒーティング法」に着目した．この手法は，腫瘍内に高周波磁場により発熱する感温磁性体 (Ferromagnetic Implant with Low Curie Temperature: FILCT) を注射し，体外に配置した Drive coil から高周波磁場を印加することで，誘導加熱により患部をピンポイント加温する手法である．さらに，FILCTは一定温度（キュリー点）に到達すると透磁率が低下し発熱が停止する可逆的な性質があるため，温度制御のための温度測定が不要であり，患者への負荷を軽減できるメリットがある．しかしながら，FILCT の発熱効率は低く，Drive coil を体表上に設置して加温する場合，治療可能な温度である約45℃まで発熱する加熱可能距離は1.0cm以内であった．そこで，加熱可能距離を伸長するために，渦電流損により高い発熱効率が期待できる金を FILCT にコーティングした「Au-FILCT」および，高周波磁場下で高い発熱特性を示す Resovist®と FILCT の混合物である「ResoReso-FILCT」が報告されている．しかしながら，金コートおよび Resovist®はタンパク変性を引き起こす50℃を越えても発熱し続けるため温度測定が必要である．そこで，発想を転換し，FILCT を発熱体としてだけではなく，温度計測用プローブとして利用する手法が考案されている．しかしながら，治療時の Drive coil および Pickup coil を想定した配置かつ体内を模擬した環境での治療可能距離は調べられていない．
本論文では，ワイヤレス温度計測・誘導加熱システムを構築し，体内環境を模擬した37℃恒温環境におけるFILCT，Resovist®，Au-FILCT および Reso-FILCTを加熱しながら温度検知が可能となる Drive coil から発熱体までの距離を物理実験により検証することを目的とする．
本システムを構築するにあたり，治療時に印加する高周波磁場を発生させるために，大型の誘導加熱電源EKOHEATを採用した．さらに，異なる距離に設置した2個の Pickup coil に発生する誘導起電力を Circuit box 内の信号重畳回路に入力することで印加磁束のドリフト成分を低減させた重畳電圧を Lock-in Amplifier にて同期検波した．同時に，サンプルの温度をリファレンスデータとして光ファイバー温度計により計測した．これらを3Dプリンタにて製作した相対的な位置姿勢に固定するための骨格となる治具にて一体化した．さらに，サンプルの周囲を断熱材にて密閉し，恒温水槽より37℃の恒温水をシリコンチューブ内に循環することにより，37℃恒温環境を再現したワイヤレス温度計測・誘導加熱システムを構築した．本実験の手順として，初めに高周波磁場を発生させ Circuit box 内の重畳回路の可変抵抗を調節し，重畳電圧をキャリブレーションした．その後，Drive coil 上面からサンプル下端までの距離（以降，サンプルまでの距離と呼ぶ）が1.0cmとなる様にサンプルを設置し，磁場を印加しサンプルの温度が50℃を越えるか300秒経過するまで測定した．その後，サンプルまでの距離を1.0cm刻みで延伸させ，測定開始から300秒経過してもサンプルの温度が45℃に到達しなくなる距離まで測定を続けた．
各発熱体の重畳電圧と温度を上記の条件にて計測した結果，FILCTの治療可能距離は1.0cm以内であったが，Au-FILCTおよびReso-FILCTでは5.0cmまで治療可能距離を延伸することを明らかにした．さらに，距離1.0 cmにおけるFILCT，Resovist®，Au-FILCTおよびReso-FILCTの温度と重畳電圧の関係を比較した結果，Au-FILCTはFILCTの6.1倍の初期温度変化率と1.27倍の重畳電圧の変化量を持ち，Reso-FILCTはFILCTの3.6倍の初期温度変化率と1.28倍の重畳電圧の変化量を持つことを明らかにした．また，距離5.0cmにおけるAu-FILCTおよびReso-FILCTの温度と重畳電圧の関係を比較した結果，Au-FILCTはReso-FILCTの0.75倍の初期温度変化率と2.1倍のS/N比を持つことを明らかにした．さらに，Au-FILCTの45℃における重畳電圧値を閾値として利用することで，LabVIEWにより誘導加熱電源に制御コマンドを送信し自動温度制御可能な「ワイヤレス温度計測・自動定温加熱システム」を構築し，妥当性を物理実験により検証した．その結果，5.0cmの条件であっても温度を一定の範囲に制御可能であることを明らかにした．
本研究により得られた「ワイヤレス温度計測 ・誘導加熱システムにおけるAu-FILCTおよびReso-FILCTの温度検知と同時に加温を可能とする最大深度」についての知見を利用した「ワイヤレス温度計測・自動定温加熱システム」により，体表面から5.0cmまでの腫瘍に対して本手法によりハイパーサーミアによる治療効果が期待できる．
本論文は全7章で構成されている．第1章を序論とし，本研究の背景および目的について述べる．第2章にて，本論文にて扱うハイパーサーミアの原理について，生理学的および電磁気学的見地から説明する．第3章では，本論文にて利用する「ワイヤレス温度計測手法」について説明する．第4章にて，本論文にて構築した「ワイヤレス温度計測・誘導加熱システム」の構成および要素を明示し，物理実験により構築したシステムの妥当性を検証する．第5章にて，発熱効率を向上させた新規発熱体について明示し，体内環境を模擬した37℃恒温環境を付加したワイヤレス温度計測・誘導加熱システムにて，物理実験により各種発熱体の温度検知および加温可能距離を検証する．第6章にて，37℃恒温環境を付加したワイヤレス温度計測・誘導加熱システムを利用した「ワイヤレス温度計測・自動定温加熱システム」を構築し，物理実験によりシステムの妥当性を検証する．第7章は結論で，本研究により得られた主な知見および今後の課題について述べている
An abnormal flow profile of Internal Jugular Vein in Patients Implanted with Pacemaker-leads
Get PDF秋田大学博士（医学
Rare Metal Mineralization of the Khaldzan Burgedei Peralkaline Complex, Western Mongolia
Get PDF秋田大学博士（工学）The Khaldzan Burgedei peralkaline complex in western Mongolia is an example of extreme enrichment of Zr, Nb, and REEs in A-type granite. The Khaldzan Burgedei was discovered by Kovalenko.V.I in 1984. Preliminary resources calculated (1989-1990) area total of 163.8 Mt resources at ZrO₂ (1.5 wt.%), Nb₂O₅ (0.2 wt.%), Ta₂O₅ (0.01 wt.%), REE₂O₃ (0.3 wt.%) and Y₂O₃ (0.11 wt.%) (Minin et al., 1991). The objectives of this study is to clarify petrology, mineralogy and geochemistry identify rare-metal bearing minerals, and discuss the genesis of HFSE and REEs mineralization based on the samples, which were collected from a drill holes and outcrops in the complex. The study was conducted on the basis of microscopic observations, X-ray diffractometry (XRD), scanning electron microscopy (SEM-EDS), X-ray fluorescence spectrometry (XRF), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), electron probe microanalyser (EPMA), Fluid inclusion microthermometry and Laser Raman Spectra.
The studied area of the Khaldzan Burgedei complex consists of two main lithologic units of quartz syenite and granite are identified by the result of field and drill core observation. The quartz syenite is dominantly distributed in the study area and they are intruded by granite. A sharp contact between quartz syenite and granite is observed in the outcrops, and sometimes the contact between quartz syenite and granite shows a mingling characteristic. The zone, which has an average width of about 2-5.5m, consists of compositionally and texturally inhomogeneous rocks of syenite and pegmatite.
The quartz syenite is coarse-grained, mainly consists of K-feldspar, plagioclase, albite, ferrorichterite, arfvedsonite, aegirine-augite, aegirine, and quartz with accessory apatite, rutile, zircon and pyrochlore. The granite is fine-grained, mainly consists of quartz, K-feldspar, albite, arfvedsonite and aegirne with accessory zircon and fersmite. The quartz syenite is occur in the all drill holes and most of drill core basically affected by metasomatism and some interval subsequent hydrothermal alteration with chamosite, nontronite, calcite, fluorite, pyrite, zircon and REE bearing minerals (synchysite, bastnasite, parasite and xenotime). The granite is occur several drill holes and upper part of the granite, in the drill holes becomes quartz rich compared to the lower part. The quartz rich part is related to fractionation. This part is sometimes associated with pegmatites that consist of amphibole, feldspar, and quartz with zircon and fersmite.
The bulk rock compositions of the drill core show metsomatized and subsequent hydrothermal alteration units, is enriched in Ca, Nb, Zr, and REE, fractionated unit because of high SiO₂ (71.5-79.3 wt%), is enriched in Rb, Ce, Nd, and total REEs. Pegmatite show sharp spikes of Nb and Zr.
The peralkaline magma evolved from quartz syenite to granite associated with pegmatite. This is supported by similar igneous mineral assemblies and chemical characteristics of the quartz syenite and granite. Differentiated rocks, such as quartz syenites and granites, amphibole evolves from ferrorichterite to arfvedsonite and pyroxene is aegirine-augite to aegirine. This indicates show evolution of the magma changing to from sodic-calcic to more sodic composition during crystallization. The results of EPMA data show were precipitated of mafic minerals more lose Ca in the granite, during the granitic magma evolution and/or especially silica oversaturation.
The three HFSE and REE enrichment processes (magmatic, metasomatism and hydrothermal) are observed in the Khaldzan Burgedei complex. One is the fractionation of the granitic magma that accumulated HFSE and REEs (especially LREEs) at the top of the granitic stock and associated pegmatites. The fractional crystallization can produce residual magmas that are strongly enriched in the HFSE and REE. The other is the Na metasomatism and subsequent hydrothermal alteration. The Na metasomatism and hydrothermal fluid were enriched in volatiles (CO₂, B, F and Cl) and incompatible elements (HFSE and REE). These volatile elements are helped transported REE carbonates. Effects of the metasomatism primary minerals are replaced by secondary minerals. This replacement indicates that Ca from plagioclase and Ca-bearing mafic minerals (ferrorichterite and aegirine-augite) were the source of Ca for fluorite, calcite and REE-bearing carbonates (synchysite).
The reactions during the metasmatism are as follow:
3(Na,Ca)(Si,Al)₄O₈(Plagioclase) + Na⁺ + 10H⁺ = 2NaAlSi₃O₈(albite) + 3Ca²⁺ + 10Al³⁺ + 2Na⁺ + 3Si₂O + 5H₂O (1)
Na₂CaFe²⁺₅Si₈O₂₂(OH)₂ (Ferrorichterite) + 1.5Na₂Si₂O₅ + O₂ + Fe³⁺ = 5NaFe³⁺Si₂O₆(Aegirine) + SiO₂ Quartz + Ca²⁺ + Fe²⁺ + 1.5OH⁻ + 0.5H⁺ (2)
Ca²⁺ + 2F⁻ = CaF₂ (Fluorite) (3)
REEF²⁺ + Ca²⁺ + 2CO₃²⁻ = CaREE(CO₃)₂F (Synchysite) (4)
After metasomatism, albite altered by sericite and chlorite, and aegirine altered by chlorite. During this alteration, Cl formed from aegirine and this released Cl helped to transport REE. This process is explained by replacement reactions related to acidic alteration.
The reactions during the hydrothermal alteration are as follow:
4NaFe³⁺Si₂O₆ Aegirine + 2H₂O + 4H⁺ + 2FeCl₂ = Fe₆Si₄O₁₀(OH)₈ Chamosite + 4SiO₂ + 4Na⁺ + 4Cl⁻ (1)
REECl²⁺ + HF + HCO₃⁻ = REE(CO₃)F Bastnäsite + 2H⁺ + Cl⁻ (2)
Feldspars replaced by smectite (nontronite) and Fe-rich chlorite (chamosite) and hydrothermal minerals formed later than feldspar also includes HFSE and REE bearing minerals. Exsolving fluorine and sodium rich hydrothermal fluids leached HREEs from zircon and transported the host quartz syenite. This hydrothermal fluids reacted (Na metasomatism) with feldspars and Ca-bearing amphibole resulting in the precipitation of fluorite, calcite and HREE rich zircon as well as REE carbonates.
In summary, we propose a genetic model that the HFSE and REE mineralization of the complex we caused by extreme magmatic fractionation and subsequent Na metasomatism resulted in albitization and fluorite precipitation with extracted Ca²⁺. Destabilized Zr-REE fluoride complexes resulted in zircon and REE minerals precipitation
Risk Factors Linking Esophageal Squamous Cell Carcinoma With Head and Neck Cancer or Gastric Cancer.
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Human frozen-thawed blastocyst morphokinetics observed using time-lapse cinematography reflects the number of trophectoderm cells
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Correlation of plasma concentration and adverse effects of bosutinib: standard dose or dose‑escalation regimens of bosutinib treatment for patients with chronic myeloid Leukemia
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Research of finger bone position and posture estimation method utilizing magnetic motion caputure - Development of skeletal finger model for estimating finger motion -
Get PDF秋田大学博士（工学）Motion capture is an important technology for surgical operation training, such as ergonomic assessment of hand motions in laparoscopic surgery. Researches relating to wrist angle and finger joint angles with glove-based motion capture device are available. However, hand motion and finger joint positions during laparoscopic surgery has not been discussed in previous researches because finger position measuring method for laparoscopic training has yet to exist within our knowledge. There are also some researches on dexterous movements using hand motion capture methods that applies methods such as optical motion capture. However, these researches are not related to laparoscopic training. To measure the hand motion of surgical operation when using scissor-like tools, such as laparoscopic instruments, the self-occlusion problem with optical motion capture cannot be avoided, as optical markers may be occluded by either the hands or surgical instruments. To address the occlusion problem, a magnetic motion capture device that is capable of finger motion measurement as magnetic field is able to pass through human body is useful solution. Another problem that needs to be addressed is the physical collision between the aforementioned instruments and magnetic receivers. When using scissor-like laparoscopic instruments, the handgrip may collide with magnetic receivers. In order to reduce these physical collisions, the number of receivers that placed on finger have to be reduced. As the result, skeletal finger model is necessary to estimate position finger segments that do not have receivers placed on them.
In this paper, we proposed a method to develop skeletal finger model for the estimation of finger motion when using scissor-like tools. We developed a calibration method for receiver posture, an estimation method for joint rotation center and rotation axis, and a joint center positions estimation method utilizing two receivers attached on fingertip and hand dorsum. In addition, we have measured and evaluated the motion of index finger which includes bone length (segmental length) and finger bone position by attaching receivers on the fingertip and hand dorsum during grasping. Furthermore, we compared the fingertip position generated by the proposed skeletal finger model to a finger model with rotation axes orthogonal to the finger bone.
For evaluating the skeletal finger model, we compared the fingertip positions generated by the proposed skeletal finger model to that of a finger model with rotation axes orthogonal to the finger bone. As the result, the mean (standard deviation) distance between the fingertips of all subjects and all target positions was 2.6 mm (0.9 mm). Compared to a finger model with rotation axes orthogonal to the finger bone, the mean error and standard deviation of the finger model generated by the proposed skeletal finger model was reduced by 45% and 47%, respectively. It is confirmed that the skeletal finger method generated by our method had better accuracy and reproduced a more realistic finger motion.
Further, we evaluated the mean segment lengths during a specified grasping motion were calculated by determining the position of joint centers. As the result, the standard deviations of all estimated segment lengths were under 0.2 mm . The positions of the joint centers obtained through our method with that obtained by attaching a full set of four receivers between the dorsal hand and index fingertip were compared. The Pearson correlation coefficients between the joint center positions estimated by our method and that of full set of receivers were calculated. The results showed a strong correlation between the joint center positions estimated by our metho