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水産廃棄物アコヤガイ貝殻真珠層から作製した真珠層抽出成分の抗不 安・抗うつ作用の検討
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）●第1章：背景・目的
真珠は古くから近視やてんかん、痙攣に効く生薬として利用されている。真珠は骨形成や
皮膚再生、抗酸化作用など様々な生理活性作用を示すことが報告されているが、詳しい作
用メカニズムや有効成分はほとんど明らかになっていない。一方、真珠貝であるアコヤガ
イの貝殻には真珠とほぼ同じ組成を示す真珠層が含まれているが、多くの貝殻は水産廃棄
物として処理されている。当研究室はこれまで、アコヤガイ真珠層から作製した真珠層抽
出成分が、スコポラミンやアミロイドβで誘発した記憶障害を抑制することを明らかにし
てきた。真珠層抽出成分の機能についてさらに調べるため、本研究では、不安・うつモデ
ルマウスに対する真珠層抽出成分の効果について検討を行った。
●第2章
本章では、リポポリサッカライド(LPS)で誘発した不安・うつ症状マウスモデルに対する
真珠層抽出成分の効果を検討した。行動薬理試験の結果から、LPS 投与マウスでは
control よりも強い不安・うつ行動がみられたが、真珠層抽出成分を腹腔内投与すること
でマウスの不安・うつ行動が抑制されることが分かった。また、真珠層抽出成分の抗不
安・抗うつ作用に、抗酸化作用や抗炎症作用、セロトニン受容体の発現制御、BDNF の増
加といった複数のメカニズムが関連していることが明らかになった。
●第3章
本章では、老化に伴う不安・うつ症状に対する真珠抽出液の効果を明らかにするため、老
化促進マウス(SAMP8)を用いて検討を行った。真珠層抽出成分を経口投与することでSAMP8
マウスの老化に伴う不安・うつ症状を抑制した。さらに、SAMP8 マウスの攻撃行動や概日
リズムの乱れに対しても抑制効果がみられたことから、真珠層抽出成分の老化に伴うBPSD
（認知症患者に生じる、知覚認識または思考内容または気分または行動の障害）に対する
有効性が示された。またRNA シークエンス解析やウェスタンブロットの結果から、真珠層
抽出成分はSAMP8 マウスの脳で生じるER ストレスや神経炎症を抑制することで抗不安、
抗うつ作用を示していることが明らかになった。
●第4章
複数のカラムを用いて真珠層抽出成分に含まれる抗不安・抗うつ物質を単離・同定したと
ころ、約750kDa の硫酸多糖が抗不安・抗うつ作用に寄与していることが明らかになっ
た。この有機成分は以前、スコポラミン誘発性記憶障害を改善する成分として単離した成
分であった。また、真珠層硫酸多糖の作用経路を検討したところ、真珠層硫酸多糖はエク
ソソームを介して脳に作用している可能性があることが明らかになった。
●結論
真珠層抽出成分は不安症状やうつ病だけでなく、BPSD を抑制する機能性食品として役立
てることができる可能性がある。●The 1st chapter: Background and purpose Pearls have been traditionally used as
medicine for conditions such as myopia, epilepsy, and convulsions. They have
been reported to exhibit biological activities, including bone formation and
skin regeneration. However, the detailed mechanisms of action and the specific
bioactive components remain largely unknown. Pearl oyster shells contain a
nacreous layer with a composition similar to that of pearls, yet most of these
shells are discarded as fishery waste. Our laboratory previously demonstrated
that nacre extract prepared from pearl oyster shells suppresses scopolamine- and
amyloid-β-induced memory impairment. To further explore the functionals of
nacre extract, I investigated its effects using mouse models of anxiety and
depression.
●The 2nd chapter
In this chapter, I examined the effects of nacre extract using a mouse model of
LPS-induced anxiety and depression. LPS-treated mice exhibited more anxious and
depressive behaviors than control mice, but intraperitoneal administration of
the nacre extract suppressed the anxious and depressive behaviors of the mice.
The results suggest that multiple mechanisms—including antioxidant and antiinflammatory
effects, regulation of serotonin receptor expression, and increased
brain-derived neurotrophic factor (BDNF) levels—contribute to the anti-anxiety
and antidepressant effects of nacre extract components.
●The 3ed chapter
In this chapter, I investigated whether nacre extract could alleviate agerelated
anxiety and depression using senescence-accelerated mouse P8 (SAMP8)
models. Oral administration of nacre extract suppressed anxious and depressive
behaviors as well as aggressive behavior and circadian rhythm disturbances in
SAMP8 mice.These findings suggest that nacre extract may also be effective
against behavioral and psychological symptoms of dementia (BPSD) associated with
aging. RNA sequencing analysis and western blotting results indicated that the
effects of nacre extract are mediated by the suppression of endoplasmic
reticulum (ER) stress and neuroinflammation.
● The 4th chapter
The isolation and identification of anti-anxiety and antidepressant substances
in the nacre extract revealed that a sulfated polysaccharide of approximately
750 kDa contributed to these effects. This component had previously been
identified as a substance that ameliorates scopolamine-induced memory
impairment. Further investigation suggested that this sulfated polysaccharide
may act on the brain via exosomal pathways.
● Conclusion.
Nacre extract may serve as a functional food or drug candidate for suppressing
BPSD as well as depression and anxiety.doctoral thesi
The Application of ETC2.0 Probe Data and Network Clustering in Investigating Urban Mobility Patterns During an Extreme Snow Event
No full textImplementing the Vehicle-to-Infrastructure with the upgraded electronic toll collection systems (ETC2.0) has transformed Japan's transportation infrastructure by elevating it into one of the foremost Intelligent Transport Systems. Despite the wealth of data provided by ETC2.0, its application in studying urban mobility patterns under extreme weather conditions remains limited. This study examines the impact of heavy snowfall on the mobility network in Sapporo, Japan, using ETC2.0 probe data. By comparing mobility patterns on selected heavy snow and normal days in February 2022, the study identifies significant changes in network structure and community distribution. Findings reveal that heavy snowfall causes fragmentation of mobility networks, with notable shifts in community locations and node centrality. The study underscores the importance of maintaining connectivity to industrial and commercial areas during extreme weather events and highlights the need for further research into the relationship between community structures and travel behavior.journal articl
Composition-dependent ultrafast luminescence in Cu-Ni alloys: Combined experimental and abinitio study
Get PDFProperties of Cu-Ni solid solutions have long been studied in physical and materials sciences. Yet, their many-body properties have not been well understood. Here, we investigate ultrafast luminescence in near infrared region for Cu1−xNix alloys. The luminescence intensity was the highest in Cu and decreased dramatically by adding Ni, approaching close to the value for pure Ni at x = 0.45. This composition dependence was well reproduced by calculations assuming two body scattering of the energetic electrons. The luminescent decay rate was not straightforward, i.e., it decreased first by adding Ni up to x = 0.17 and then started to increase approaching twice the initial value at x = 0.45. This behavior was in good agreement with ab initio calculations of electron-phonon (e-ph) coupling strength. This work provides a new perspective on the electron relaxation dynamics in solid solutions systems.journal articl
Broadband multimode interference coupler based on SiN waveguide designed by the adjoint method
No full textAn inverse-designed broadband multimode interference (MMI) coupler based on SiN waveguide is proposed. The widths of the waveguides are modulated based on an adjoint sensitivity analysis. Starting from a gray refractive index distribution, the distribution is binarized at the final design stage to enable the fabrication of the device. Only some tens of iterations are necessary to obtain converged geometry. By modulating the widths of the MMI region, the spectra become very flat over the 100-nm wavelength range. The characteristics of the device are further improved by optimizing the input and output waveguide widths, in addition to the width of the MMI region. The designed device is fabricated, and the measured transmission spectra are in excellent agreement with the calculation, showing the usefulness of the design method. Over 100-nm broadband 3-dB splitting is experimentally demonstrated.journal articl
Anomalous chirality dependence of strain energy in gold nanotubes
Get PDFA recent experiment reports a creation of goldene, which is two-dimensional gold with hexagonal structure. By rolling up the goldene, gold nanotubes (GNT) should exist, but their structural and electronic properties are not understood well. Based on first-principles calculations, we demonstrate a breakdown of inverse square law, wherein the strain energy stored in a GNT decreases with the inverse square of the GNT radius. This is due to the enhanced strain energy in specific GNTs. The specific chiralities are identified by imposing the Bloch and geometric boundary conditions to the electronic structure of goldene having a hexagonal shape of Fermi surface. We also confirm that the electronic states on the Fermi surface exhibit in-plane character. These factors result in an increase in the strain energy.journal articl
Finite element full vectorial bi-directional beam propagation method for efficient design of cascaded optical waveguide components
No full textA full-vectorial bidirectional beam propagation method (FV-BiBPM) for the numerical analysis of stair-case optical waveguide components is developed. In this method, a transversal cross section of an optical waveguide is discretized by the finite element method (FEM) based on edge-node hybrid elements and wave propagation in the longitudinal direction is computed by propagation operators. Since an optical waveguide is typically an open system, a perfectly matched layer is employed to treat radiation modes. We show that FV-BiBPM based on the FE scheme (FEFV-BiBPM) can successfully compute wave propagation, including radiation waves, through a numerical analysis of a waveguide gap. As a further numerical validation and an application of the FEFV-BiBPM, a waveguide grating and a coupler between a strip waveguide and a sub-wavelength grating waveguide are analyzed and investigated. The numerical results of the FEFV-BiBPM are in good agreement with well-established 3DFEM using tetrahedra edge elements and show that our method can save computational cost, especially for memory usage, in the design of stair-case optical waveguide components.journal articl
反復有限要素法とCMA-ESを用いた非線形光デバイスの最適設計
Get PDF光Kerr 効果を利用した光デバイスは，高速に応答する光スイッチが実現可能であり，線形光デバイ
スでの実現が難しい全光論理ゲートや光リミッタなどの実現が可能である．しかしながら，非線形問題を直接解
くことは一般に容易ではない．そのため，適当な初期解を用いた反復解法がよく用いられるが，解の収束性に注意
する必要がある．本研究では，伝搬解析手法として用いる反復有限要素法の収束性の改善を行い，構造表現手法
として関数展開法，最適化手法として共分散行列適応進化戦略(CMA-ES) を用いた非線形光デバイスの最適設計
について検討を行っている．最適設計例として光スイッチと光NAND ゲートをとりあげ本手法の有用性を示す．journal articl
潜在パターン抽出による行動誘導：ユーザ軌跡分析における次元性駆動型イノベーション
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）To address the risk level assessment of multi-view traffic risk records, we propose a Self-weighted Multiview Spectral Clustering on Multiple Manifolds (SwMMC) algorithm. SwMMC leverages the Constrained Laplacian Rank framework to directly partition data by imposing rank constraints on the similarity matrix, eliminating the need for post-processing steps like K-means. To reduce noise, it combines similarity measures from both high-dimensional and projected low-dimensional spaces during matrix construction. By alternatingly optimizing the ideal affinity matrix and view weights, SwMMC adaptively fuses multiple views. Comparative experiments on two real-world datasets demonstrate its superior performance in risk level classification across diverse conditions.
For traffic networks, traffic signal control is crucial for improving transportation efficiency. Traditional reinforcement learning methods for traffic control have problems like slow learning speed and poor adaptability to new situations. To solve these issues, we introduce MetaSignal, a meta-reinforcement learning approach that uses Fourier basis linear function approximation. This approach maps high-dimensional traffic states to low-dimensional linear combinations via Fourier basis, reducing memory and computation costs while capturing feature interactions like queue intensity and phase time. Combined with a model-agnostic meta-learning framework, MetaSignal enables fast adaptation to dynamic traffic without extensive retraining. Empirically, the proposed method shows promising and stable performance for traffic signal control through comprehensive comparison experiments in both synthetic and real-world traffic networks.
In summary, this research proposes two paradigm-specific frameworks for behavioral trajectory guidance: SwMMC for multi-view traffic risk assessment and MetaSignal for traffic signal control. By integrating constrained spectral ranking and Fourier basis approximation, the study advances dimensionality-adaptive methodologies, demonstrating enhanced performance in risk classification and traffic control across real-world scenarios.多視点交通リスク記録のリスクレベル評価を課題として，本研究では自己重み付き多流形多視点スペクトラルクラスタリング（Self-weighted Multiview Spectral Clustering on Multiple Manifolds: SwMMC）アルゴリズムを提案する。SwMMC は，制約付きラプラシアンランクフレームワークを利用し，類似度行列にランク制約を課すことでデータを直接分割し，K-means などの事後処理ステップを不要とする。ノイズ低減のため，行列構築時に高次元空間と射影された低次元空間の双方の類似度測度を組み合わせる。理想的なアフィニティ行列と視点重みを交互に最適化することで，SwMMC は多視点を適応的に融合する。2 つの実データセットにおける比較実験により，多様な条件下でのリスクレベル分類において優れた性能が実証された。
交通ネットワークにおいて，交通信号制御は輸送効率向上の鍵となる。伝統的な交通制御用強化学習手法は学習速度が遅く，新しい状況への適応性が低いという問題を有する。これらの課題を解決するため，本研究ではフーリエ基底線形関数近似を用いたメタ強化学習アプローチである MetaSignal を導入する。当該アプローチは，フーリエ基底を介して高次元交通状態を低次元の線形結合に写像することで，メモリと計算コストを削減しながら，車列密度や相位時間などの特徴の相互作用を捉える。モデル非依存メタ学習フレームワークと組み合わせることで，MetaSignal は大規模な再学習を必要とせずに動的な交通状況への高速適応を可能にする。実験的には，合成および実世界の交通ネットワークにおける包括的な比較実験を通じて，提案手法が交通信号制御において有望かつ安定した性能を示した。
本研究は行動軌跡ガイダンスのための2つのパラダイム固有のフレームワークを提案した：多視点交通リスク評価用の SwMMC と交通信号制御用の MetaSignal。制約付きスペクトラルランキングとフーリエ基底近似を統合することで，本研究は次元適応的手法を進展させ，実世界のシナリオにおけるリスク分類と交通制御における性能向上を実証した。doctoral thesi
対称ジエステルの選択的モノ加水分解反応の大量スケールへの発展と開環メタセシス重合による置換ポリノルボルンネン合成への応用
Get PDF室蘭工業大学博士（工学）対称ジエステルにおける等価な２つのエステル基の片方のみを高選択的にモノ加水分解する反応は、有機合成や高分子化学において有用な中間体であるハーフエステルの合成手法として長年注目されてきた。
本研究では、まずシュウ酸の対称ジエステルを用いた高選択的かつmolという大量スケールでのモノ加水分解法を確立した。具体的には、塩基としてKOHまたはNaOHの水溶液を用い、水またはTHF/水の共溶媒系にて穏和な条件下で反応を行い、ハーフエステルを高収率・高選択性で得ることができた。塩基の種類、濃度、溶媒の組成、反応スケール（ミリモルからモルスケールまで）を系統的に最適化することで、本手法の実用性を明確に示した。特に、シュウ酸のハーフエステルは市販品が限られており、従来法ではシュウ酸の対称ジエステルの２つの等価なエステル基の片方のみを加水分解することが困難であるため、本法の意義は大きい。
さらに、上記の対称ジエステルのモノ加水分解反応を利用して得られたハーフエステルを機能性モノマーとして活用し、開環メタセシス重合（ROMP）による高分子（ポリノルボルネン誘導体）の合成に応用した。Grubbs第2世代および第3世代ルテニウム触媒を使用することで、ノルボルネン類骨格を持つハーフエステルの誘導体を重合し、エステル基やアミド基を持つ多様な機能性ポリマーを合成した。特に第3世代触媒（G3）の使用により、迅速かつ分散度の狭い重合が可能となり、ハーフエステル由来のモノマーが精密構造のポリマー材料構築に有望であることが明らかとなった。また、重合条件（モノマー/触媒比、反応時間、モノマーの置換基の構造など）と生成高分子の分子量、分子量分布、トランス含有率との関係を詳細に検討し、モノマー設計や触媒選択が高分子特性に与える影響について体系的な知見を得ることができた。
ROMPで得られた高分子は、エステル基やアミド基を側鎖に有し、後処理としての脱保護や官能基変換が容易であり、さらなる高分子修飾や応用展開の基盤となるものである。これらの高分子材料は、コーティング剤、分離膜、医療材料、バイオマテリアル、さらには刺激応答性材料など、多様な応用可能性を秘めており、機能性高分子材料の新たな設計指針を提供するものである。
以上の成果は、小分子有機合成技術（モノ加水分解）と高分子合成技術（ROMP）の融合による、新しい合成戦略を提示したものであり、精密高分子合成の分野において今後のさらなる発展や新規材料創製への道を拓くものと考えられる。本研究で確立した手法と得られた知見は、学術的意義にとどまらず、産業応用における有用な基盤技術としても期待される。Selective monohydrolysis of symmetric diesters has proven to be a reliable and versatile synthetic strategy for preparing half-esters, which serve as valuable intermediates in organic synthesis, materials science, and polymer chemistry. In this dissertation, we established a practical, scalable, and efficient method for the synthesis of monoalkyl oxalates via base-mediated selective monohydrolysis. The developed protocol employs mild conditions using aqueous KOH or NaOH in water or THF-water biphasic systems and achieves high selectivity for monoester formation while minimizing overhydrolysis to diacids. Reaction conditions, including base type, base equivalents, temperature, solvent system, and reaction time, were systematically optimized, and the method was demonstrated across a range of scales from millimole to molar quantities. The resulting monoalkyl oxalates were obtained in high yields and purities, providing an accessible route to compounds that are otherwise difficult to source commercially.
Building on this synthetic platform, the prepared half-esters were successfully applied as functional monomers for the construction of polynorbornene derivatives through ring-opening metathesis polymerization (ROMP). Employing both second- and third-generation Grubbs ruthenium catalysts, we demonstrated the polymerization of various norbornene- and norbornadiene-based monomers bearing ester, amide, and mixed functional groups. The use of the third-generation Grubbs catalyst, characterized by its enhanced initiation efficiency due to the incorporation of labile pyridine ligands, significantly improved polymerization rates and control over molecular weight distribution. Our investigations highlighted the effects of monomer structure (including substituent size and configuration), monomer-to-initiator ratio ([M]/[I]), and reaction time on polymer yield, molecular weight, polydispersity (Mw/Mn), and trans content. We found that smaller ester substituents (such as methyl or ethyl groups) facilitated higher yields and better control, while bulkier groups (such as isopropyl or tert-butyl) introduced steric hindrance that modestly lowered conversion efficiency.
Importantly, this research illustrates the direct translation of small-molecule monohydrolysis chemistry into functional polymer synthesis. The integration of monohydrolysis-derived half-esters into ROMP-enabled polymerization allowed for the creation of polymers with amphiphilic character, precise structural control, and tunable physical properties. Moreover, we demonstrated post-polymerization modifications, such as deprotection and amide formation, expanding the versatility of these materials for applications in coatings, membranes, biomedical devices, and responsive materials.
This dissertation provides not only a practical synthetic methodology for monoalkyl oxalates but also establishes a modular framework for designing and producing functional polymers with customizable architectures. The work contributes to the field by offering insights into monomer design, catalyst selection, and structure–property relationships in ROMP-derived materials, paving the way for future developments in precision polymer chemistry.doctoral thesi
エナンチオ選択的不斉反応に用いる新規カゴ型アミノアミド有機分子触媒の開発
Get PDF室蘭工業大学Muroran Institute of Technology博士（工学）医薬品を含む多くの生物活性化合物は光学活性物質であり,その鏡像異性体は異なる生体内活性を示すことが多いため,有効な一方の鏡像異性体を高選択的に合成するための不斉合成反応，特に不斉触媒を用いる触媒的不斉合成反応の開発が重要である.その不斉触媒の中で，金属を含有しない有機分子触媒は空気中で安定であり取り扱いやすく安価であるという利点などを有するため,次世代の環境調和型触媒として現在活発に研究開発が行なわれている.
著者は,新規多点認識型有機分子触媒としてカゴ型アミノアミド型触媒を設計し,それを,エナンチオ選択的ß-ケトエステル類とニトロスチレン類との不斉マイケル付加反応にそれぞれ適用し，その有機分子触媒としての機能性を明らかにした.
カゴ型アミノアミド有機分子触媒 Aを用いるß-ケトエステル類 とニトロスチレン類との不斉マイケル反応を検討した．その結果，触媒 A が不斉触媒活性を示し, 本反応によってほぼ完全な化学収率と優れた光学収率で光学活性マイケル付加体が得られることを見出した．得られたマイケル付加体は，創薬のための様々な生物活性化合物の合成中間体として有用であり，この合成中間体から新薬候補化合物を創製できることが期待される．
本研究において著者は，「基質との共有結合部位と水素結合部位，さらには反応のエナンチオ選択性の制御に有効な多環式芳香族環部位を併せ持つ多点認識型カゴ型アミノアミドハイブリッド型触媒」を開発することに成功し,それらが創薬に有効な不斉マイケル付加反応において良好な不斉触媒活性を示すことを明らかにした. また，本反応によって得られる化合物は様々な医薬品をはじめとする生物活性化合物の合成中間体として有用であることから，本研究の成果は, 新薬創製の合成開発研究に大きく貢献できると期待される.Many biologically active compounds, including pharmaceuticals, are optically active and often only one of the enantiomer shows a high biologically activity. Therefore, it is important to develop the synthetic methodology for providing only necessary enantiomer. As the methodology, catalytic asymmetric synthesis, in which the use of a low amount of a chiral catalyst theoretically enables infinite production of optically active compounds, is the most efficient in the synthetic organic
chemistry field. Moreover, this methodology is also important in terms of energy saving and environmental friendliness. The chiral catalysts used in catalytic asymmetric syntheses can be divided into two categories of organometallic catalyst and metal-free organocatalyst. Particularly, organocatalyst is stable in air, easy to handle, and inexpensive, so they are being focused on as next-generation, environmentally friendly catalysts.
Author developed the new cage-typed 2-azanorbornane-based amino amide organocatalyst. This catalyst is expected to work as multipoint recognition catalyst having both covalent and non-covalent hydrogen bonding sites in the single molecule. This catalyst was successfully derived from commercially available amino acids, and the excellent catalytic activities were demonstrated in the Michael addition.
The enantioselective asymmetric Michael reaction of β-keto esters with nitro olefins using 2-azanornane-based amino amide organocatalysts was carried out to provide chiral Michael adducts in excellent chemical yields, diastereoselectivities and enantioselectivities. The obtained Michael adducts with chiral quaternary carbon center are important synthetic precursors of the synthesis of many biologically active compounds including pharmaceuticals such as platencin (antibiotic).
In this study, author revealed that the new explored cage-typed amino amide organocatalyst showed satisfactory catalytic activities in the Michael addition. It is expected that this result should be able to greatly contribute the development of new drug and its related compounds.doctoral thesi