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要旨 : 隼人と呼ばれた南九州の人々が律令国家の支配を受け容れた要因について、武力で制圧され服従したとする のが従来の一般的な理解であった。こうした征服史観的な見方に対しては批判もあるが、現状では克服しきれてい ない。この研究史的課題に取り組むため、本稿では、前稿「古代南九州にルーツを持つ中央官人（上）」で検証した 大隅乙万呂の検証結果と、筆者が以前検証した大隅忌寸公足、大隅忌寸三行、大隅直坂麻呂、薩麻君国益の成果を 総合して、古代南九州にルーツを持つ中央官人を分析する。そして、どの程度の数の人たちがどういった官職に任 じられたのか、誰がいかなる過程で中央官人になったのかを明らかにした。そのうえで、南九州の人々が律令国家 の支配を容認した要因を考察した。

要旨 : 隼人と呼ばれた南九州の人々が律令国家の支配を受け容れた要因について、武力で制圧され服従したとする のが従来の一般的な理解であった。こうした征服史観的な見方に対しては批判もあるが、現状では克服しきれてい ない。この研究史的課題に取り組むため、本稿では、平城京左京三条二坊八坪東二坊坊間路西側溝から出土した飯 支給伝票に記載されており、古代南九州にルーツを持ち、都で活動していたと推測される大隅乙万呂について、基 礎的考察をおこなった。

Fatty acid amide hydrolase (FAAH) is a key enzyme in the endocannabinoid system. N-(3,4-Dimethylisoxazol-5-yl)piperazine-4-[4-(2-fluoro-4-[11C]methylphenyl)thiazol-2-yl]-1-carboxamide ([11C]DFMC) was developed as an irreversible-type positron emission tomography (PET) ligand for FAAH. Here, we attempted to noninvasively estimate rate constant k3 as a direct index for FAAH in the rat brain. First, the two-tissue compartment model analysis including three parameters (K1–k3, 2TCMi) in PET study with [11C]DFMC was conducted, which provided 0.21 ± 0.04 mL·cm−3·min−1 of the net uptake value (Ki), an indirect index for FAAH, in the FAAH-richest region (the cingulate cortex). Subsequently, to noninvasively estimate Ki value, the reference model analysis (Patlak Reference, PGAREF) was tried using a time-activity curve of the spinal cord. In that result, the noninvasive Ki value (KREF) was concisely estimated with high correlation (r > 0.95) to Ki values based on 2TCMi. Using estimated KREF value, we tried to obtain calculated-k3 based on previously defined equations. The caluculated-k3 was successfully estimated with high correlation (r = 0.95) to direct k3 in 2TCMi. Finally, the dose relationship study using calculated-k3 demonstrated that in vivo ED50 value of URB597, a major inhibitor of FAAH, was 66.4 µg/kg in rat brain. In conclusion, we proposed the calculated-k3 as an alternative index corresponding to regional FAAH concentrations and suggested that PET with [11C]DFMC enables occupancy study for new pharmaceuticals targeting FAAH.

Iodide homeostasis and thyroid hormone metabolism in the brain are potentially related to changes in the activity of the sodium iodide symporter (NIS). No radiotracers are currently available for imaging brain NIS activity. Here, we synthesized 6[124I]iodo-9-pentylpurine that can noninvasively measure iodide efflux from the brain and showed that the efflux rate of [124I]I− in NIS knockout mice was 84% lower than that of wild-type mice. Thus, 6-[124I]iodo-9-pentylpurine would be useful for imaging brain NIS activity.

We report a case of leptospirosis in Tokyo in winter due to a rat bite, an uncommon cause of Leptospira infection. In Japan, many cases due to exposure to fresh water have been reported from domestic southwest islands in summer. However, a previous report on leptospirosis in Tokyo documented several cases occurring in winter. The main route of infection in the Tokyo metropolitan area during winter was attributed to the increased chance of direct rat exposure. Rapid and feasible diagnostic methods are needed to elucidate its epidemiology and provide prompt treatment.

Titanium dioxides were reduced to metallic titanium via molten salt electrolysis using CaCl2. It was reported that the efficiency was low because some side reactions produced carbon precipitates. To produce titanium more efficiently, these electrochemical side reactions were examined by cyclic voltammetry (CV). O2- reacted with the carbon anode to form CO and CO2 gas bubbles, which easily dissolved into the molten salt and formed CO32-, subsequently generating carbon powder. CV was performed after interrupting electrolysis temporarily. The electrochemical reduction of CO32- in the cathodic scan was not observed, suggesting that CO32- was spontaneously reduced by Ca during electrolysis. Anodic reactions preceding Cl2 gas generation occurred in three steps: CO and CO2 gas generation related to O2-, and successive CO2 generation related to CO32-.

The transient behavior of the multi-interfacial flow can be modeled using recent Smoothed Particle Hydrodynamics (SPH) model. This developed numerical method is fully-Lagrangian particle-based approach, which can track the movement of many fluid phase directly. The advantage of this simulation model is a direct calculation in both of dispersed phase and continuous phase seamlessly. Thereby this model estimates transient behavior of interfacial behavior by predicting the changes of each interface shape. For example, numerical simulations have been performed for different conditions corresponding to different values of surface tension, viscosity and density, and the predicted topological changes as well as the theoretical interfacial shape of droplets can be validated. Based on this model, we carried out relatively large-scale interfacial flow simulations, investigated case studies of metallurgical processing, and evaluated the non-steady state flow of formed from various dispersed phase.

In order to check the solubility of CaS during sulfide reduction in molten CaCl2, the mixture of CaCl2 and a small amount of CaS was melted in Ar at the range from 1123 K to 1223 K. The melt was sampled by quartz tube and rapidly solidified. The solidified samples showed a lamella structure with CaS particles, which results in a simple eutectic reaction between CaCl2 and CaS. Using ICP-AES analysis, the saturation of CaS was found to be completed within 1.8 ks, and 1.77 ± 0.1 mol%CaS at 1173 K was measured as the solubility limit at the initial composition of 3.0 mol%CaS. A tentative phase diagram of CaCl2–CaS binary system was proposed based on the solubility analysis in these temperatures and eutectic structure.

Solubility of CaS in molten CaCl2–65 mol%LiCl eutectic salt was examined by sampling of CaS saturated salt and ICP analysis. The handling in dried environment and an adequate mass of melt were applied for reliable measurements, in addition to suppression of inclusion of CaS particles. The solubility limit was found to be 0.22 ± 0.05, and 0.31 ± 0.05 mol%CaS at 873 K and 973 K, respectively. This saturation value was less than 1.77 ± 0.1 mol%CaS in pure CaCl2 at 1173 K.

アルミニウムおよびその合金を、主として酸性水溶液に浸漬してアノード酸化（陽極酸化）すると、アルミニウム表面にポーラス型アノード酸化皮膜が生成する。ポーラス皮膜はアルマイトやポーラスアルミナともよばれ、アルミニウムに耐食性や機械的特性、装飾性を付与する表面処理皮膜として極めて重要である。さらに近年、その特異なナノ構造を利用し、さまざまなナノテクノロジーへの応用が切り開かれつつある。ポーラス皮膜に関する総説・解説論文は表面技術誌上でこれまでにも掲載されているが、本論文においては最新の研究成果を踏まえつつ、ポーラス皮膜の成長挙動やナノ構造の基礎について、あらためて平易に概説したい。本特集号に掲載されているバリヤー型アノード酸化皮膜に関する総説および次号に掲載予定のアノード酸化の歴史に関する総説を併読すると、より理解が深まる。また、ポーラス皮膜を利用したナノテクノロジーについて、近年世界的に注目されている研究をご紹介したい。

The dynamic structure function in real space G($r,E$) is deduced from the dynamical structure factor S($Q,E$) which can be obtained from inelastic neutron scattering measurement. In this study, we applied the G($r,E$) analysis to NaI which is a typical alkali halide crystal. The optic and acoustic phonons of NaI are widely separated in energy because the difference in mass between the constituent atoms is large. These characteristic properties certainly help us to evaluate the G($r,E$) features associated with the phonon modes. We measured the S($Q,E$) for NaI powder using the Fermi chopper spectrometer 4SEASONS at J-PARC, and converted S($Q,E$) into G($r,E$) by newly developed software which utilizes the maximum entropy method. Our analysis clearly demonstrated the G($r,E$) of TO mode oscillates out of phase with that of LA mode, which is physically reasonable. Further analyses will be given in the presentation., 実空間における動的構造関数G($r,E$)は、非弾性中性子散乱実験により得られる動的構造因子S($Q,E$)から導出される。本研究では、典型的なアルカリハライド結晶であるNaIにG($r,E$)解析を適用した。NaIは、構成元素の質量差が大きいために光学フォノンと音響フォノンのエネルギー差が大きくなるが、この特性はG($r,E$)解析の妥当性を評価する上で有効である。J-PARCのフェルミチョッパー分光器四季で測定したNaI粉末のS($Q,E$)に対して、最大エントロピー法を利用した新開発の解析ソフトウェアを使ってG($r,E$)に変換したところ、LAモードとTOモードが逆位相で振動することを見出した。この結果は物理的に妥当なものであり、G($r,E$)解析の有用性を如実に示している。本発表ではさらなる解析結果について報告を行う予定である。

有用な11C標識中間体である[11C]HCNの製造には、現状では専用の製造機器/設備が必要である。そこで、多くの11C製造施設で用いられている[11C]CH3Iから特別な機器/設備が無くても簡便かつ効率的に[11C]HCNを製造する方法の開発を行った。【方法】[11C]CH3Iを種々のトリアルキルアミンN-オキシド溶液を担持した石英綿に120℃で2分間通じることで[11C]HCHOに変換し、これをヒドロキシルアミン硫酸エステル（HOSA）を担持した石英砂に150℃で2分間通じることで[11C]HCNを得た。各試薬はガラスカラムに保持させ、加熱はシリコンラバーヒーターで行った。【結果】[11C]HCHOの生成において、石英綿に担持させるN-オキシド溶液の溶媒は、スルホキシド系溶媒が適切であった。 [11C]HCHOのHOSAとの反応では無溶媒でも効率的に[11C]HCNが得られた。N-オキシドにオキシマトリンを用いることで、従来の方法と同等の収率かつ十分な比放射能の [11C]HCNが得られた。合成時間は、照射終了から15分以内で完了した。【結論】本方法を用いることで、[11C]CH3Iを製造している施設であれば簡便かつ効率的に[11C]HCNを製造し利用することができる。, 第60回日本核医学会学術総会

身近な食品や医薬品等の摂取により、生体内では毒物として知られているシアン化物 イオン(CN-)が生成され、CN-はさらに代謝を受けチオシアン酸イオン(SCN-)となる。 SCN-は神経障害を惹起する中毒性を持つと考えられているため、脳にはSCN-を排出す ることでSCN-の脳内濃度を低く保つ機構の存在が示唆されているが、SCN-の排出を非 侵襲的に定量評価できる方法は未だ開発されていない。従って、SCN-排出の定量評価 が可能となれば、SCN-の中毒性の評価や排出メカニズムの解明に大きく貢献すると考 えられる。今回は、血液脳関門を通過し、脳内で速やかに[11C]SCN-を遊離すること が期待されるalkyl thiocyanate、aryl thiocyanate、6-thiocyanatopurine誘導体を 設計し、標識合成の検討を行った。合成はハロゲン前駆体と[11C]SCN-との反応、あ るいは[11C]CN-を用いたジスルフィド結合の開裂反応により行い、短い反応時間で目 的物の生成が認められた。詳細については、本会にて報告する。, 第60回日本核医学会学術総会

Multidrug resistance-associated protein 1 (MRP1) is a member of the adenosine triphosphate–binding cassette superfamily of transporters and plays an important role in limiting the permeation of xenobiotics and exporting endogenous substances across the blood-brain and blood-cerebrospinal fluid barriers, and across brain parenchymal cells in the central nervous system. In addition to multidrug resistance, changes in activity or expression of cerebral MRP1 occur in several brain diseases. Therefore, noninvasive and quantitative assessment of MRP1 activity in the brain is valuable for investigating the changes in MRP1 related to brain diseases, towards an understanding of the underlying molecular mechanisms. In this chapter, we will focus on 6-bromo-7-[11C]methylpurine for imaging MRP1 activity, as well as the concept of the metabolite extrusion method (MEM) for measuring efflux transporter activity. Several positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging studies of MRPs activity are also reviewed. Finally, we discuss our recent findings regarding the contribution of Mrp1 in brain parenchymal cells to tracer efflux, and the sensitivity of 6-bromo-7-[11C]methylpurine for measuring MRP1 activity.

Hydration water dynamics were measured by quasi-elastic neutron scattering with H2O/D2O contrast for two DNA dodecamers, 5’CGCGAATTCGCG’3 and 5’CGCGTTAACGCG’3, which have been computationally shown to be structurally rigid and flexible, respectively. The dynamical transitions of the hydration water as well as DNA were observed for both sequences at approximately 240 K. Above the transition temperature, the mean square displacements of the hydration water for the rigid sequence were smaller than those for the flexible one. Furthermore, the relaxation time of the hydration water was longer in the rigid DNA than in the flexible DNA. We suggest that hydration water dynamics on the picosecond timescale are associated with sequence-dependent deformability of DNA.

Accumulation of detrimental glutathione-conjugated metabolites in the brain potentially causes neurological disorders, and must therefore be exported from the brain. However, in vivo mechanisms of glutathione-conjugates efflux from the brain remain unknown. We investigated the involvement of transporters in glutathione-conjugates efflux using 6-bromo-7-[11C]methylpurine ([11C]1), which enters the brain and is converted into its glutathione conjugate, S-(7-[11C]methylpurin-6-yl)glutathione ([11C]2). In mice of control and knockout of P-glycoprotein/breast cancer resistance protein and multidrug resistance-associated protein 2 ([Mrp2]−/−), [11C]2 formed in the brain was rapidly cleared, with no significant difference in efflux rate. In contrast, [11C]2 formed in the brain of Mrp1−/− mice was slowly cleared, whereas [11C]2 microinjected into the brain of control and Mrp1−/− mice was 75% cleared within 60 min, with no significant difference in efflux rate. These suggest that Mrp1 contributes to [11C]2 efflux across cell membranes, but not BBB. Efflux rate of [11C]2 formed in the brain was significantly lower in Mrp4−/− and organic anion transporter 3 (Oat3)−/− mice compared with control mice. In conclusion, Mrp1, Oat3, and Mrp4 mediate [11C]2 efflux from the brain. Mrp1 may contribute to [11C]2 efflux from brain parenchymal cells, while extracellular [11C]2 is likely cleared across the BBB, partly by Oat3 and Mrp4.

A 3D scanning technique was applied for understanding coke shapes obtained by a rotational strength test, and a numerical dynamic analysis based on the multi-sphere type discrete element method was carried out to clarify the influence of coke degradation on the packed structure. We constructed a trickle flow simulation of molten slag via the smoothed particle hydrodynamics model, and the liquid-gas permeability characteristics exhibited by the coke shapes in the lower part of the blast furnace are discussed accordingly. Coke diameter decreased due to collisions between particles, via the progress of surface- and volume-destruction, and that the particles subsequently became sphere-like in shape. Static holdup of molten slag showed a decreasing tendency with the coke degradation progress, as the void shape and holdup site became spatially uniform as sphericity increased. In the case of packed bed formed by the initial low sphericity or large-sized cokes, the size of the air gap was maintained, although the flow path was non-uniform. Therefore, even if the large amount of holdup did not block the gaseous main flow, in the case of lower coke strength, the sphericity increased due to the deformation progress, and void uniformity could be retained. However, the existence of many narrow void regions remarkably decreased the gas permeability.

アルミニウムを中性のホウ酸塩やリン酸塩に浸漬してアノード酸化（陽極酸化）すると、アルミニウム上に緻密なバリヤー型酸化皮膜が生成する。一方、硫酸、シュウ酸、リン酸およびクロム酸などの酸性水溶液を用いてアルミニウムをアノード酸化すると、ナノサイズの細孔が無数に配列したポーラス型酸化皮膜（ポーラスアルミナ）が生成する。これら2種類のアノード酸化法は、電解コンデンサにおける誘導体皮膜やアルミニウムの耐食性向上、装飾性の付与などに幅広く応用されており、アルミニウムおよびその合金の表面処理法として工業的に極めて重要である。アルミニウムのアノード酸化に関する研究開発は20世紀初頭に始まり、電気化学的なアノード酸化挙動の評価、走査型・透過型電子顕微鏡の発達によるアノード酸化被膜の詳細な観察とナノ構造の理解、各種アルミニウム実用材料への応用展開、そして最先端ナノテクノロジーとしての進化と、この100年間にわたって日本の研究者たちが世界をリードしてきたことは特筆すべきことである。一方で、アノード酸化に限らず、あらゆる科学技術が加速度的に発達したこの21世紀において、100年を超える歴史をもつ古い技術であるアノード酸化に、これ以上の劇的な進展が見込めるのか？という疑問をぶつけられることが少なからずある。その答えはわからない。しかし、その壁を壊して新しい世界を見つけることの楽しさこそが、ScienceとEngineeringの教育・研究機関で仕事をすることの醍醐味でもある。著者らは、公益財団法人軽金属奨学会の平成27年度課題研究として、新規なアルミニウムのアノード酸化を探索し、新しい機能を発現するための研究を遂行する機会を幸運にも得た。「試行的冒険的要素大なるも可」。募集要項の記載である。アノード酸化とは何か、原点に立ち戻ったときに素直に感じた疑問点を深く追求し、そこから得られた新しいアルミニウムのアノード酸化と機能の発現について試行・冒険した成果の概略を報告させていただきたい。

Cardiovascular disease (CVD) is the leading cause of death and disease burden worldwide. Nuclear myocardial perfusion imaging with either single-photon emission computed tomography or positron emission tomography has been used extensively to perform diagnosis, monitor therapies, and predict cardiovascular events. Several radiopharmaceutical tracers have recently been developed to evaluate CVD by targeting myocardial perfusion, metabolism, innervation, and inflammation. This article reviews old and newer used in nuclear cardiac imaging.

Positron emission tomography (PET) allows biomolecular tracking but PET monitoring of brain networks has been hampered by a lack of suitable reporters. Here, we take advantage of bacterial dihydrofolate reductase, ecDHFR, and its unique antagonist, TMP, to facilitate in vivo imaging in the brain. Peripheral administration of radiofluorinated and fluorescent TMP analogs enabled PET and intravital microscopy, respectively, of neuronal ecDHFR expression in mice. This technique can be used to the visualize neuronal circuit activity elicited by chemogenetic manipulation in the mouse hippocampus. Notably, ecDHFR-PET allows mapping of neuronal projections in non-human primate brains, demonstrating the applicability of ecDHFR-based tracking technologies for network monitoring. Finally, we demonstrate the utility of TMP analogs for PET studies of turnover and self-assembly of proteins tagged with ecDHFR mutants. These results establish opportunities for a broad spectrum of previously unattainable PET analyses of mammalian brain circuits at the molecular level.

Preferential decomposition of CO2 gas to CO gas was examined by using a combination of CaCl2-CaO melt as a reaction media and ZrO2-8mol% Y2O3 solid-state electrolyte as anode. The conversion ratio of CO2 to CO became larger at the higher temperature, and approached the maximum (88.2%) at 1273 K. The highest CO concentration was generated at cell voltage of 2.55 V, which is close to theoretical decomposition voltage of CaO. Therefore, in addition to calciothermic reaction between precipitated Ca and CO2 gas bubbles, CO2 decomposes preferentially via the decomposition reaction of carbonate ions. Namely CO2 gas dissolves to form CO3 2- under coexistence of CaO in the melt, CO3 2- precipitates carbon or CO gas bubbles on the cathode, and a part of carbon reacts with the blown CO2 gas to form CO. CO gas is used as an effective fuel with easy handling in steel plants.

To form glossy plating of Al on a Cu substrate, electroplating of Al was conducted in an ionic liquid mixture of 1-ethyl-3-methylimidazolium chloride and aluminum chloride (EMIC-AlCl3) containing 1,10-phenanthroline (Phen). The electroplated surface smoothness obtained using an Al-plate counter electrode was improved by stirring of the electrolyte. The reflectivity at the center of the specimen surface formed by a stirring rate of 400 rpm was the highest at 74.7% with stirring rates from 0 to 400 rpm and the reflectivity of the specimen was higher at the edge than at the center. The results suggest that the glossy surface of the substrate was enhanced by uniformity of the electrolyte in contact with the substrate. When the counter electrode was replaced with the Al mesh, the electroplated surface was glossy throughout the surface without stirring. Diffusion of the electrolyte through the Al mesh might have produced an effect similar to stirring of the electrolyte.

Electrochemical decomposition of CaTiO3 at the cathode was examined in a scheme of titanium metal production from natural deposit, Ilmenite (TiFeO3). Based on the possible precipitation of CaTiO3 from TiFeO3, the electrochemical decomposition of CaTiO3 is here examined using combination of the calciothermic reduction and the electrolysis of CaO in the same molten salt. Inhomogeneous reduction in the cathodic basket is related with buoyancy of Ca and insufficient dehydration. By optimizing the cooling conditions, CaO content in the molten salt, and dehydration method, an industrial level of 0.42 mass%O could be achieved as powder form.

Metallic vanadium was successfully produced starting from vanadium sulfide by applying electrolysis in molten CaCl2. Vanadium sulfide filled in a cathodic Ti basket and a graphite anode were immersed in the melt of CaCl2-CaS at 1173 K in Ar, and the electrolysis was conducted at a cell voltage of 3.0 V. Sulfide electrolysis did not form carbon deposit and was free from carbon contamination, while carbon powder was formed on the cathode in the oxide electrolysis using the melt of CaCl2-CaO. When the CaS content in the molten CaCl2 increased, electrolysis current increased resulting in fast smelting while the oxygen and sulfur contents in metallic vanadium increased. Oxygen and sulfur contents as low as 3390 ppm and 210 ppm, respectively, were achieved by supplying about four times more electrical charge than stoichiometry.

Resonance Bio International Symposium

Objectives Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide and various closely related structural analogs to form positively charged pyridinium ions and contributes to the nicotinamide clearance and xenobiotic detoxification. NNMT is expressed primarily in the liver but has been found in other tissues at lower levels. Recent studies have shown relationships between changes in NNMT expression and several diseases. In the brain, Parkinson's disease patients have higher levels of NNMT protein and activity compared with normal subjects. In vivo imaging of NNMT activity would therefore be helpful for elucidation of pathological conditions. Here, we present the synthesis of [11C]nicotinamide analogs for imaging NNMT activity in the brain. To find a blood-brain barrier permeable tracer with the moderate methylation rate, which is required for NNMT imaging, five candidate tracers were designed in consideration of kinetic parameters of NNMT substrates [1]. Methods [11C]Nicotinamide, 4-methyl[11C]nicotinamide, and 3-quinoline[11C]carboxamide were synthesized by the Pd(0)-mediated [11C]carbomethoxylation of the corresponding pinacol esters with [11C]carbon monoxide in methanol followed by hydrolysis with aqueous ammonia solution. [11C]Thionicotinamide and 4-methylpyridine-3-[11C]carbothioamide were synthesized by the thoiamidation of the corresponding [11C]cyanopyridines using sodium hydrogen sulfide in N,N-dimethylformamide (DMF) at 90°C. The [11C]cyanopyridines were prepared by the reaction of the bromo precursors with [11C]ammonium cyanide in DMF at 180°C. Results The radiochemical yields of the isolated [11C]nicotinamide, 4-methyl[11C]nicotinamide, 3-quinoline[11C]carboxamide, [11C]thionicotinamide, and 4-methylpyridine-3-[11C]carbothioamide from [11C]carbon dioxide were 2.7  1.1%, 4.3  3.5%, 5.4  0.1%, 7.8  6.6%, and 4.0  3.5% (decay corrected to the end of bombardment), respectively. Their radiochemical purities were >95%, and molar activity was in the range of 7.4 to 82 GBq/μmol at the end of synthesis. Conclusions We have achieved the synthesis of the candidate tracers, [11C]nicotinamide analogs, for imaging NNMT activity in the brain. Further in vivo studies are in progress. References [1] van Haren MJ et al., Biochemistry, 2016, 55, 5307−5315, ISRS2019 (the 23rd International Symposium on Radiopharmaceutical Sciences)

Objectives. [11C]Cyanide is a useful intermediate for labelling functional groups such as CN, COOH, CONH2 and CH2NH2 in organic compounds. Conventional method for the preparation of [11C]cyanide, however, requires dedicated infrastructure. [11C]Cyanide is generally prepared by heating [11C]CH4 under NH3 gas flow at more than 900°C over a platinum filled column. Furthermore, the starting material, [11C]CH4, is produced by the irradiation of N2/H2 gas or by heating [11C]CO2 under H2 gas flow over nickel. In the previous meeting (ISRS2017), we reported that [11C]cyanide was prepared by the dehydration of [11C]formaldoxime, though the radiochemical yield was insufficient (around 20% from [11C]CO2). Thus, we explored more efficient method to prepare [11C]cyanide without any special equipment and reagents. In this study, we investigated the applicability of hydroxylamine-O-sulfonic acid (HOSA) to [11C]cyanide preparation from [11C]CH3I which is widely used for 11C-labelling. HOSA has been used as a reagent for the conversion of aldehydes into nitriles. Methods. [11C]CH3I (300–400 MBq) was trapped in a 1 mL of trimethylammonium oxide (TMAO, 15 mg) solution in DMF or DMSO and heated for 2 min to prepare [11C]HCHO (at 70°C for DMF solution, at 100°C for DMSO solution). The [11C]HCHO solution (200 μL) was subsequently added to the HOSA solution in the corresponding solvents (200 μL). The reaction conditions are summarized in Table 1. Radiochemical yields from [11C]CH3I were determined by radio-HPLC analysis of the reaction solution. More than 87% of radioactivity in the injected solution was eluted during the HPLC analysis. Results. The results are summarized in Table 1. Higher reaction temperature enhanced the formation of [11C]cyanide. The use of DMSO showed better yield of [11C]cyanide compared with DMF. The use of more than 1 equivalent of HOSA based on the amount of TMAO was required to obtain good yields of [11C]cyanide. Consequently, [11C]cyanide was produced in 87% radiochemical yield after 3 min reaction time. Conclusions. [11C]Cyanide was efficiently prepared from [11C]CH3I in one-pot using conventional reagents and lab-ware. Further optimization of reaction conditions for the production of [11C]cyanide with an automated system is in progress., ISRS2019 (The 23rd International Symposium on Radiopharmaceutical Sciences)

CuI is a well-known superionic conductor in a high temperature solid phase where the mobile cations migrate between interstitial sites in the f.c.c. sublattice formed by iodine ions. Even in the molten state, it shows several features suggesting collective or cooperative ionic motion. MD results show that Cu diffuses much faster than I. The Cu-Cu partial structure factor have a FSDP which indicates a medium-range ordering of Cu ions. Moreover the Cu-Cu partial pair distribution deeply penetrates into the nearest neighboring Cu-I shell. To reveal origin such anomalous behaviors of molten CuI, we performed quaiselastic neutron scattering (QENS) by the disk-chopper spectrometer AMATERAS at MLF, J-PARC. To interpret the total dynamic structure factor obtained from coherent QENS, the mode distribution analysis was applied. It is found that the motion of iodine is a kind of fluctuating within an almost local area while Cu ions diffuse much faster than iodine ions., ヨウ化銅は高温固相で、ヨウ素イオンが作る面心立方格子の隙間を銅イオンが動く超イオン伝導体になることで知られている。溶融相でも、集団的あるいは協調的なイオンの運動を示す特徴がある。MDシミュレーションにおいて、銅イオンの拡散がヨウ素イオンより非常に速いこと分かっている。Cu-Cu部分構造因子にはFSDPと呼ばれる構造を持ち、銅の分布に中距離秩序があることを示している。さらに、Cu-Cu部分二体分布関数は、Cu-Iで形成される最近接分布に深く入り込んでいる。そうした溶融CuIの異常的振る舞いの原因を解明するために、J-PARCの物質・生命科学実験施設に設置されたディスクチョッパー分光器AMATERASを用いて、中性子準弾性散乱(QENS)実験を行った。構造可干渉性のQENSから得られた動的構造因子を理解するため、モード分布解析を行った。その結果、ヨウ素イオンの運動が局所的に閉じ込められた空間で揺らぐような運動であること、一方銅イオンはヨウ素イオンより速く拡散する運動をしていることが分かった。

アルミニウムのアノード酸化（陽極酸化）は、アルミニウムおよびその合金に耐食性や装飾性、機能性を付与する表面処理法として極めて重要なプロセスであり、電気化学反応によってアルミニウム上に生成する酸化アルミニウム（アルミナ）をナノメータースケールの精度で緻密に制御できる。アルミニウム素地がいかに素晴らしい物理的・機械的特性を持っていたとしても、表面に何らかの問題があれば、例えば容易に腐食するならば、そのアルミニウムを実用材料として用いることは困難である。その観点からアルミニウムのアノード酸化に関する研究開発は非常に長い歴史を持ち、21世紀の今現在も発展し続けている先端技術である。特に近年、高規則ポーラスアルミナの作製と各種ナノテクノロジーへの応用に関する研究が異分野からも注目を集めている。著者らはここ数年来の研究において、新規な電解質化学種を用いてアルミニウムをアノード酸化することにより、新しいアノード酸化挙動やナノ構造、そしてその結果として発現する新しい機能性を持つアノード酸化皮膜の作製に挑戦している。これまでの研究により、高電圧アノード酸化、硬質皮膜の形成、構造色の発現など興味深い知見が得られつつある。本論文においてはその一つとして、アルミニウムのピロリン酸（脱水素重合二リン酸、H4P2O7)アノード酸化によって生成するアルミナアナノファイバーの成長機構とナノファイバー形成アルミニウム表面が発現する超親水性、超撥水性についてご紹介したい。

Multidrug resistance-associated protein 4 (MRP4) and organic anion transporter 3 (OAT3) mediate the efflux of organic anions from the brain and heart. In this study, we have developed a probe for estimating the activity of these transporters in these tissues using positron emission tomography. Several 11C-labeled hippuric acid ester derivatives were screened with the expectation that they would be hydrolyzed in situ to form the corresponding 11C-labeled organic acids in target tissues. Among the compounds screened, benzyl [11C]hippurate showed favorable hydrolysis rates and uptake properties in the target tissues of mice. Subsequent evaluation using transporter knockout mice revealed that radioactivity was retained in the brain and heart of Oat3(-/-) and Mrp4(-/-) mice, respectively, compared with that of control mice after the intravenous administration of benzyl [11C]hippurate. Benzyl [11C]hippurate could therefore be used as a probe for estimating the activities of OAT3 and MRP4 in mouse brain and heart, respectively.

A new numerical model was successfully developed for analyzing packed bed structures containing non-spherical solids such as cokes and the high-temperature melt trickle flow characteristics of such beds. This enables the direct three-dimensional analysis of packed beds that are difficult to visualize in experimental tests. The sophisticated smoothed particle hydrodynamics (SPH) method can track the motion of liquids without discriminating between continuous and dispersed phases. Meanwhile, the advanced discrete element method (DEM) is employed as a highly-accurate method for solid-particle motion simulation. It is a method using a contact force model that is expanded to capture the motion of 3-dimensionaly freely shaped rigid bodies. We used the boundary for the packed bed configured with non-spherical solids to carry out a trickle flow simulation. Based on this model, we carried out the largescale simulations, and perform case studies and other studies of statistical processing, and investigate the effects of both physical properties and packed bed formed from various types of non-spherical cokes.

A panel of radiochemicals has enabled in vivo positron emission tomography (PET) of tau pathologies in Alzheimer’s disease (AD), although sensitive detection of frontotemporal lobar degeneration (FTLD) tau inclusions has been unsuccessful. Here, we generated an imaging probe, PM-PBB3, for capturing diverse tau deposits. In vitro assays demonstrated the reactivity of this compound with tau pathologies in AD and FTLD. We could also utilize PM-PBB3 for optical/PET imaging of a living murine tauopathy model. A subsequent clinical PET study revealed increased binding of 18F-PM-PBB3 in diseased patients, reflecting cortical-dominant AD and subcortical-dominant progressive supranuclear palsy (PSP) tau topologies. Notably, the in vivo reactivity of 18F-PM-PBB3 with FTLD tau inclusion was strongly supported by neuropathological examinations of brains derived from Pick’s disease, PSP, and corticobasal degeneration patients who underwent PET scans. Finally, visual inspection of 18F-PM-PBB3-PET images was indicated to facilitate individually based identification of diverse clinical phenotypes of FTLD on a neuropathological basis.

A liquid metal electrochemically deposited in CaCl2 or its chloride melts serves as an effective reductant for active metal oxides. Although a very low oxygen concentration can be achieved at a considerably high electrolysis efficiency, the existence of small amount of water impurity in molten chlorides, which is very difficult to detect, causes low electrolysis efficiency. In this study, to clarify the morphological and thermal characteristics of a cathodic electrode in a slightly hygroscopic LiCl-KCl-CaCl2 melt, we simultaneously performed electrochemical measurements and thermal measurements using an ultrafine thermocouple inserted inside a Mo electrode (i.d. 1.57 mm). Concomitantly, changes in the electrode interface were recorded at 500-mu s intervals using a synchronized high-speed digital camera. Despite the small amount of water included in the system, the measured heat absorption was much smaller than thermodynamically predicted, which suggested that the generated hydrogen decreased the purity of the liquid alloy electrodeposited on the cathode surface possibly through hydride formation. By using the synchronized thermal measurement, it was possible to trace the change in the electrodeposition pattern of impurity water quickly and sensitively, which was difficult to determine in only the electrochemical potential-current response.

国際ワークショップ「遺伝子導入技術の利用による霊長類脳機能操作とイメージング」

Introduction [11C]PBB3, a Tau imaging agent, is rapidly metabolized to form a sulfate conjugate ([11C]PBB3-sulfate) in peripheral tissues by sulfotransferase (SULT).1 After the administration of [11C]PBB3 to mice, [11C]PBB3-sulfate was observed also in the brain. The previous report concluded that it was due to the influx of [11C]PBB3-sulfate from blood to brain. However, it is known that SULT is expressed in the brain and [11C]PIB which possesses 6-hydroxybenzothiazole as a fundamental structure (Fig 1) is sulfated in the rat brain.2 It was therefore expected that [11C]PBB3, a [11C]PIB derivative, would be sulfated in the brain. In this study, the sulfate conjugation of [11C]PBB3 in the brain was investigated because the conjugation might affect the kinetic analysis of Tau imaging with [11C]PBB3. In addition, the hydrolysis of [11C]PBB3-sulfate to form parent [11C]PBB3 in the brain was investigated as sulfate conjugates can be hydrolyzed by sulfatase which is expressed in the brain. Materials & Methods Sulfate conjugation of [11C]PBB3 in the brain was evaluated by adding [11C]PBB3 and a sulfate donor, 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to the brain homogenate sample. In mice samples (cerebrum, C57BL/6, 8 wo, n=3), reactions were carried out at 37°C for 30 min. In samples of a rhesus monkey (frontal cortex, Macacca mulatta, male, 23 yo), reactions were carried out at 37°C and the conjugates generated were analyzed at 5, 15, 30 min after starting reaction. In addition to the crude homogenate (around 0.2 g/mL for mice, 0.16 g/mL for monkey), the sulfate conjugation in the supernatant of homogenate was investigated. The conjugation was analyzed using radio-TLC. Similarly, [11C]PBB3-sulfate, which was prepared by O-sulfation of [11C]PBB3 using sulfur trioxide pyridine complex, was incubated in the mice brain homogenate at 37°C for 30 min to evaluate its hydrolysis. Results The sulfate conjugation of [11C]PBB3 was observed in the mice brain samples with 30 min reaction time, and only 7.7±0.44% and 9.2±0.30% of [11C]PBB3 was conjugated in the crude homogenate and supernatant, respectively (Fig 2A). Meanwhile, [11C]PBB3-sulfate was slowly hydrolyzed to form [11C]PBB3 in the brain sample (3.1±0.13% in the crude homogenate and 3.7±0.20% in the supernatant, Fig 2B). The conjugation rates of [11C]PBB3 in the monkey brain samples were much faster than that in the mice brain samples. The conjugation in the crude homogenate of monkey brain followed first order manner (r2=1.0) up to 91% decrease of [11C]PBB3 and the rate was estimated to be 0.49 min–1(g/mL)–1. The first order kinetics suggested that the hydrolysis rate of [11C]PBB3-sulfate in the monkey brain was much slower than the conjugation rate. Indeed, the conjugation rate and the hydrolysis rate in the supernatant prepared from 0.16 g/mL of monkey brain homogenate were estimated to be 0.35 min-1 and 0.013 min-1, respectively (Fig 3). Discussion In mice, [11C]PBB3 slowly but significantly underwent sulfate conjugation in the brain. Therefore, a part of [11C]PBB3-sulfate observed in the mouse brain after [11C]PBB3 administration would be the metabolite generated in the brain. On the other hand, the sulfate conjugation of [11C]PBB3 was quite rapid and apparently irreversible in the monkey brain samples. In this study, large Interspecies differences regarding the sulfate conjugation of [11C]PBB3 in the brain was observed. Therefore, further investigation about the conjugation of [11C]PBB3 in the human brain would be required. References 1.Hashimoto H, Kawamura K, Takei M et al. [2015] Nucl. Med. Biol. 42: 905–910 2.Cole GB, Keum G, Liu J et al. [2010] Proc. Natl. Acad. Sci. USA 107: 6222–6227, The XII International Symposium of Functional Neuroreceptor Mapping of the Living Brain

製銑プロセスは、炭素を還元材として鉄鉱石の熔融・還元を行う工程である。現在の主な製鉄用高炉は内容積3000～5000㎥の大型円筒容器で、これを満たす焼結鉱、コークスの充填層に加熱空気を通気する。図1に高炉内の流れを模式的に示す。炉内では、炉頂から装入された原料から、羽口付近のracewayと呼ばれるコークス燃焼帯まで焼く500～2800Kと幅広い温度分布が生じる。したがって、コークスのガス化や融着帯での鉱石溶融の相変化、化学反応に伴う組成不均一性、粉体の発生など多くの原因によってプロセス中は固気液相が混在する系となる。近年では、CO2排出量削減のために製銑プロセス設計の見直しが図られ、主たる方策として低コークス比操業、還元材の水素置換、高反応原料の使用が提案されてきた。これらの方法は熱力学的にはCO2排出量削減が可能だが、炉内通気性や温度・反応場にも大きな影響を与えることが予想されている。炉内の流れに停滞が生じてしまうと操業は成り立たない。CO2排出量削減のためには炉内変化に対応する技術開発が同時に求められる。適切な操業設計指針を得るため、数値解析を用いた非経験的な移動現象モデルが炉内現象予測に重要な役割を担ってきた。最近では、粒子を用いたシミュレーションの応用研究によって、離散的な固体運動や自由表面流れという従来取り扱いが困難であった現象の直接解析が実用的になってきた（例えば文献(2)）。固体粒子運動の計算方法である離散要素法(DEM)、およびその数値流体力学との連成手法、また本特集号の記事にあるメッシュフリー粒子法を用いることで、今までブラックボックスとされてきた炉内のモデリングや、直接的な数値実験の試みがなされている。今後の高炉の単位操作と物理量との新たな関係性を見出すことが期待される。本報では、DEMを中心に固気相の運動量、熱、物質を同時に解析するEuler-Lagrange法によるモデルを対象とした紹介する。

Metallic niobium powder was produced for applications in electric capacitors via calciothermic reduction of niobium hydroxide in molten CaCl2. Sub-micrometer spherical metallic particles with coral-like morphologies reflected the particle size of the starting oxide powder. A fine powder was obtained from the mixtures of niobium hydroxide and CaO or Ca(OH)2, respectively. Sintered pellets of the metallic powder showed a higher capacitance (CV) than those of the simply reduced powder without pre-treatment, because the shrinkage during sintering was smaller. The CV was as large as that of commercially sintered pellets for tantalum capacitors. Therefore, this niobium powder would act as a higher-voltage capacitor by applying chemical anodic treatment at higher voltages, and lower oxygen content in the reduced power could realize a lower leak current.

CO2 gas is decomposed to CO and C by the molten salt electrolysis using CaCl2–CaO and solid state electrolyte, zirconia, as the anode. Partially CO2 gas dissolves to form CO32– and it is electrochemically decomposed to carbon. The other portion of CO2 gas bubbles reacts with metallic Ca electrochemically deposited near the cathode, and forms C or CO gas. By increasing the flow rate of CO2 gas to the reactor, a high concentration of CO gas is generated. By increasing the concentration of CO2 gas in the initial gas, a large amount of CO gas was produced in the exhaust gas, and its rate approached to 3.32×10–8 m3/s in our experimental setup. These experimental evidences reflect the electrochemical decomposition of CO32– in the molten salt.

Carbonate ions in LiCl-Li2O salt are a source of carbon contamination in the electrolytic refining of metal oxides, and their concentration is also an essential information for understanding the CO2 decomposition process. In this study, the solubility of gaseous CO2 in molten LiCl-Li2O was studied with the goal of developing processes to decompose the oxides effectively. Ar-CO2 gas mixtures were dissolved in molten salts containing various amounts of Li2O, and the solubility of the CO2 gas was calculated by measuring the mass difference between the molten salts before and after the CO2 dissolution. The molar amount of dissolved CO2 gas was almost as large as the molar quantity of Li2O when the partial pressure of CO2 was 1.0 or 0.5 atm for Li2O concentrations in the range of 0-60 mol%. This confirms that a large quantity of the oxide ions reacted with the CO2 gas, resulting in the generation of carbonate ions.

Starting ore (ilmenite, TiFeO3) was wet-chemically treated to remove Fe and the hydroxide of titanium was neutralized. The obtained precipitate was calcined to form CaTiO3, which was electrochemically reduced to Ti in the molten CaCl2-CaO. The wasted salt containing CaO could be recycled to form CaTiO3. The operating conditions such as (NH4)2S and tartaric acid concentrations for Fe removal, supplied charge, gas pressure and cooling atmosphere for molten salt reduction were optimized to obtain low-oxygen titanium.

Objectives: NADPH oxidase produces reactive oxygen species (ROS) in physiological processes, but overproduction of ROS by this enzyme leads to oxidative stress, which contributes to the pathogenesis of various brain diseases. Acetovanillone is considered an anti-inflammatory and antioxidant agent, mainly due to blocking NADPH oxidase, and has thus been examined in many animal models of brain diseases. In such studies, understanding the brain kinetics would be important for interpreting the efficacy of acetovanillone in vivo. However, very limited work has been done on in vivo kinetics of acetovanillone in the brain. In this study, we therefore examined the brain kinetics of acetovanillone using [11C]acetovanillone and PET. Methods: [11C]acetovanillone was synthesized by the reaction of 3',4'-dihydroxyacetophenone with [11C]methyl iodide in dimethylformamide. In vivo PET studies were performed on mice, which received intraperitoneal (i.p.) administration of [11C]acetovanillone. The brain tissue of mice received i.p. administration of [11C]acetovanillone was analyzed by HPLC for the chemical form. Whether acetovanillone is converted into the glucuronide conjugate was examined by comparing brain samples treated with or without -glucuronidase. The doses of acetovanillone used in this study ranged from 1.5 g/kg to 100 mg/kg. Results: The radiochemical yield of isolated [11C]acetovanillone was 9  4% (decay corrected to the end of bombardment), and the radiochemical purity was greater than 98%. Brain radioactivity was extremely low at doses of less than 10 mg/kg; low radioactivity was observed in the brain a few minutes after the administration at doses of 25 and 50 mg/kg, and rapidly decreased thereafter. At a dose of 100 mg/kg, [11C]acetovanillone showed the moderate radioactivity uptake followed by gradual reduction. An unknown metabolite was observed in the HPLC chromatogram of brain samples for all doses, and the fraction of the unchanged form increased with increasing the doses of acetovanillone. -Glucuronidase treatment caused the disappearance of the unknown peak and increased the fraction of acetovanillone. This result demonstrated that the metabolite generated in the brain was its glucuronide conjugate. Acetovanillone has been reported to be oxidized to a dimmer (active metabolite) in vitro. In our study, however, the dimer was not observed in the brain at any doses. Conclusions: These data are useful for the evaluation of the efficacy of acetovanillone as a neuroprotective agent., 22nd International symposium on radiopharmaceutical science (ISRS)

Introduction. [11C]Cyanide has been used as a useful intermediate for incorporation of 11C-labelled functional groups such as 11COOH, 11CONH2 and 11CH2NH2 into PET probes. [11C]Cyanide is generally prepared by heating [11C]CH4 under NH3 gas flow at more than 900°C in a column filled with platinum. The traditional method, however, requires an additional system for [11C]cyanide production. In this study, we explored a facile method to prepare [11C]cyanide without any special equipment, reagents and conditions. Hooker et al. reported that [11C]HCHO is readily prepared with Me3NO from [11C]MeI in DMF.[1] Augustine et al. reported that alkyl- and aryl-aldehydes can be efficiently converted to corresponding nitriles using NH2OH‧HCl in DMSO.[2] Based on these reports, we investigated the applicability of Augustine’s reaction to [11C]cyanide preparation from [11C]MeI which is commonly used for 11C-labelling. Methods. To a 50 μL of [11C]MeI solution in DMF or DMSO (30–50 MBq), a 50 μL of saturated Me3NO (90°C (Entry 2–5). Based on these results, [11C]MeI, NH2OH‧HCl and HCl were serially mixed in a DMSO solution of Me3NO and reacted at 90°C (Entry 6, 7). Despite a report indicating that DMSO is not a suitable solvent for [11C]HCHO preparation from [11C]MeI,[1] we performed a DMF-free [11C]cyanide preparation experiment. This produced [11C]cyanide in 81% radiochemical yield after 10 min reaction time. Conclusion. We have developed a facile method for efficient [11C]cyanide preparation using conventional lab-ware. Further optimization of reaction conditions and the application of the [11C]cyanide prepared with this method are in progress. \n[1] J. M. Hooker, Matthias Schönberger, H. Schieferstein, J. S. Fowler, Angew. Chem. Int. Ed. 2008, 47, 5989–5992. [2] J. K. Augustine, A. Bombrun, R. N. Atta, Synlett, 2011, 15, 2223–2227. Introduction. [11C]Cyanide has been used as a useful intermediate for incorporation of 11C-labelled functional groups such as 11COOH, 11CONH2 and 11CH2NH2 into PET probes. [11C]Cyanide is generally prepared by heating [11C]CH4 under NH3 gas flow at more than 900°C in a column filled with platinum. The traditional method, however, requires an additional system for [11C]cyanide production. In this study, we explored a facile method to prepare [11C]cyanide without any special equipment, reagents and conditions. Hooker et al. reported that [11C]HCHO is readily prepared with Me3NO from [11C]MeI in DMF.[1] Augustine et al. reported that alkyl- and aryl-aldehydes can be efficiently converted to corresponding nitriles using NH2OH‧HCl in DMSO.[2] Based on these reports, we investigated the applicability of Augustine’s reaction to [11C]cyanide preparation from [11C]MeI which is commonly used for 11C-labelling. Methods. To a 50 μL of [11C]MeI solution in DMF or DMSO (30–50 MBq), a 50 μL of saturated Me3NO (90°C (Entry 2–5). Based on these results, [11C]MeI, NH2OH‧HCl and HCl were serially mixed in a DMSO solution of Me3NO and reacted at 90°C (Entry 6, 7). Despite a report indicating that DMSO is not a suitable solvent for [11C]HCHO preparation from [11C]MeI,[1] we performed a DMF-free [11C]cyanide preparation experiment. This produced [11C]cyanide in 81% radiochemical yield after 10 min reaction time. Conclusion. We have developed a facile method for efficient [11C]cyanide preparation using conventional lab-ware. Further optimization of reaction conditions and the application of the [11C]cyanide prepared with this method are in progress. \n[1] J. M. Hooker, Matthias Schönberger, H. Schieferstein, J. S. Fowler, Angew. Chem. Int. Ed. 2008, 47, 5989–5992. [2] J. K. Augustine, A. Bombrun, R. N. Atta, Synlett, 2011, 15, 2223–2227., 22nd International symposium on radiopharmaceutical science

アルミニウムのアノード酸化（陽極酸化）は、アルミニウムの表面処理法として古くから用いられている極めて重要な電気化学プロセスである。アノード酸化により生成した酸化アルミニウムの皮膜は、電解コンデンサの誘導体やオフセット印刷のPS版、アルミニウムおよびその合金への耐食性付与、装飾用カラーリングなど、様々な分野へ応用されている。さらに近年、アノード酸化皮膜の特徴的なナノ構造を種々のナノ構造体作製技術（ナノファブリケーション）に応用するための研究開発が活発に行われており、21世紀の現在もアルミニウムのアノード酸化は進化し続けている。特筆すべきは、過去、アルミニウムのアノード酸化に関する基礎研究およびその応用を日本がリードし、そして今現在もリードし続けていることである。日本が先端を走り続けている化学技術の分野は、世の中にそう多くはないと思われる。本解説論文においては、アルミニウムのアノード酸化被膜のうち、特に「ポーラス型アノード酸化皮膜」に着目し、どのような電解質化学種を用いてアノード酸化すると、どのような構造の酸化皮膜が生成するのか、過去から現在に至る研究成果を紹介し、あわせてそれらを応用した最新のナノファブリケーションテクノロジーを報告する。アノード酸化被膜の成長機構など、従来の解説論文に詳細が記載されている事柄については極力参考文献の簡単な紹介にとどめ、ボーラス型アノード酸化皮膜を形成するために必要な電解質化学種や電気化学的分極条件を中心として紹介したい。

Preoperative noninvasive imaging to estimate the quantity and spatial distribution of protoporphyrin IX (PpIX) accumulation in tumors induced by 5-aminolevulinic acid (ALA) administration is expected to improve the efficacy of ALA-based fluorescence-guided resection and photo- and sonodynamic therapies. PpIX synthesis from exogenous ALA has been reported to be regulated by ALA influx or ALA dehydratase (ALAD) activity, which catalyzes the first step of the synthesis. In this study, we characterized the properties of a (11)C-labeled ALA analog, 5-amino-4-oxo-[6-(11)C]hexanoic acid ((11)C-MALA), as a PET tracer to estimate PpIX accumulation.

文化交流茶話会トーク, Meeting of Cultural Exchanges

Multidrug resistance-associated protein 1 (MRP1) is a drug efflux transporter that has been implicated in the pathology of several neurological diseases and is associated with development of multidrug resistance. To enable measurement of MRP1 function in the living brain, a series of 6-halopurines decorated with fluorinated side chains have been synthesized and evaluated as putative pro-drug tracers. The tracers were designed to undergo conjugation with glutathione within the brain and hence form the corresponding MRP1 substrate tracers in situ. 6-Bromo-7-(2- [18F]fluoroethyl)purine showed good brain uptake and rapid metabolic conversion. Dynamic PET imaging demonstrated a marked difference in brain clearance rates between wild-type and mrp1 knockout mice, suggesting that the tracer can allow noninvasive assessment of MRP1 activity in vivo.

After administration of the (99m)Tc complex with N,N'-1,2-ethylenediylbis-L-cysteine diethyl ester ((99m)Tc-ECD), a brain perfusion imaging agent, the radioactive metabolite is trapped in primate brain, but not in mouse and rat. Here, we investigate the involvement of metabolite extrusion by organic anion transporter 3 (OAT3), which is highly expressed at the blood-brain barrier in mice, in this species difference. The efflux rate of radioactivity in the cerebrum of Oat3(-/-) mice at later phase was 20% of that of control mice. Thus, organic anion transporters in mouse brain would be involved in the low brain retention of radioactivity after (99m)Tc-ECD administration.