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Magneto-optical Kerr-effect measurements under pulsed magnetic fields over 40 T using a compact sample fixture
No full text40テスラ超のパルス磁場中で磁気光学カー効果測定に成功 --わずか1000分の2秒で磁石の性質を明らかに--. 京都大学プレスリリース. 2026-02-13.The magnetic field is one of the most fundamental control parameters in materials science. A pulsed magnetic-field apparatus can generate high magnetic fields that are inaccessible by conventional dc-field magnets. One important issue is that measurement techniques compatible with pulsed fields are rather limited due to short pulse duration and large electromagnetic or mechanical noise originating from field pulses. The magneto-optical Kerr effect (MOKE), the change in the state of light polarization upon reflection from magnetic materials, has the potential to become a powerful tool for investigation of magnetic properties of a wide range of materials including nontransparent materials or thin films in pulsed fields. Nevertheless, since the MOKE response is typically very small, MOKE measurements under pulsed fields are quite challenging. Here, we present a method to measure polar MOKE under high pulsed magnetic fields of 2-ms pulse width. The keys of this technique are a ferrule-based compact sample-fiber fixture and a phase-resolved numerical lock-in analysis, combined with the high-resolution optical apparatus based on an all-fiber loopless Sagnac interferometer. We succeeded in measuring MOKE signals from various ferromagnetic or ferrimagnetic samples above 40 T and down to 77 K, significantly extending the limits of previously reported pulse-field MOKE measurements. Our apparatus is simple enough to be compatible with larger-scale experiments in pulse-field facilities, thus becoming a promising tool to optically investigate material properties in pulsed fields
Debye temperatures of Au nanoparticles supported on TiO₂ and SiO₂ estimated from ¹⁹⁷Au Mössbauer spectroscopy
No full textThe Debye temperature is a parameter that reflects lattice vibrations and provides important insights into physics, chemistry, and related fields. In Mössbauer spectroscopy, it is reflected in the recoilless fraction. In ¹⁹⁷Au Mössbauer spectroscopy, the energy of γ-rays is higher than that of ⁵⁷Fe, making differences and changes in the recoilless fraction more pronounced. In this study, we investigated the properties of Au particles and the effects of the support in Au-supported catalysts using the recoilless fraction, which reflects the Debye temperature. For the Au/TiO₂ catalysts, the 10wt%Au sample exhibited a Debye temperature close to that of the bulk gold. In contrast, the 2.5wt%Au sample, in which the Au particles were finer, showed a lower Debye temperature than the bulk value. This indicates that, in the Au/TiO₂ 2.5wt%Au sample, the reduction in particle size resulted in lattice softening. Lattice vibrations influence the adsorption and migration of atoms on the surface; therefore, this difference may have affected the catalytic activity. The Au/SiO2 2wt%Au sample exhibited a Debye temperature close to that of bulk gold
The Ontology of Ecological Conscientisation: Judgement Prior to Understanding and Modes of Being Generated Through Practice
No full text本稿は2010年度に京都大学大学院教育学研究科に提出した修士論文『環境教育におけるパウロ・フレイレの「意識化」理論の再考―地球環境問題を「課題提起」する―』を改稿・再構築したものである。本稿は、「エコロジカルな意識化（ecological conscientisation）」という概念を中核に据え、意識化を理解や反省に基づく認識過程としてではなく、実践の只中で生成する存在論的出来事として再定義することを目的とする理論論文である。従来の教育哲学および批判的教育学において意識化（conscientização）は、主体が社会的・歴史的条件を理解し、それを言語化・批判的に把握する過程として捉えられてきた。しかしこの理解中心モデルは、教育実践においてしばしば見られる「理解以前に行為せざるを得ない判断」や、「事後的にしか把握されない実践的変容」を十分に説明し得ないという理論的限界を有している。本稿はこの限界を踏まえ、臨床教育学の視座および存在論的考察を導入することで、判断を認識の結果としてではなく、世界との関与の只中で生起する応答的出来事として捉え直す。その上で、ハイデガーの世界内存在論を参照しつつ、人間が常にすでに他者・歴史・環境との不可分な関係性の中に置かれているという存在論的条件が、意識化の生成を可能にしていることを明らかにする。さらに、玉置神社における弓神楽実践を理論的参照点として、理解や意味づけを抑制する実践構造が、いかにして身体的応答・沈黙・継続的関与を通して存在様式の変容をもたらすのかを検討する。そこから、エコロジカルな意識化とは、内面的な意識状態や態度変容ではなく、実践が生成する「在り方（mode of being）」の変容であることを理論的に定式化する。本稿は以上の考察を通して、意識化概念を認識論的枠組みから存在論的次元へと再定位し、臨床教育学および教育哲学における理論的射程を拡張することを試みる。This paper develops an ontological reconceptualisation of ecological conscientisation, proposing a shift from understanding-based models of conscientisation toward an account grounded in practice and modes of being. In educational philosophy and critical pedagogy, conscientisation has traditionally been understood as a process through which subjects come to critically understand and articulate the social and historical conditions shaping their lives. While this reflective and cognitive model has been influential, it remains insufficient for explaining forms of educational judgement that emerge prior to understanding and practices whose significance becomes visible only retrospectively. Drawing on perspectives from clinical pedagogy and ontological inquiry, this paper reconsiders judgement not as the outcome of cognition but as an event that arises within situated practice. Educational judgement, in this view, is not preceded by full comprehension or discursive articulation; rather, it emerges as a responsive engagement within concrete situations marked by uncertainty, responsibility, and irreversibility. To articulate the ontological conditions of such judgement, the paper engages with Heidegger's account of being-in-the-world, emphasising that human beings are always already embedded in inseparable relations with others, history, and environment. The paper further examines the practice of Yumi-kagura at Tamaki Shrine as a theoretical reference point, focusing on how practices that suspend interpretation and verbal explanation can nonetheless generate profound educational transformation. Through bodily discipline, silence, and sustained participation, such practices reconfigure the practitioner's mode of being without relying on reflective understanding. From this analysis, ecological conscientisation is theorised not as an inner mental state or attitudinal change, but as an ontological transformation of how one exists and relates within the world. By repositioning conscientisation within an ontological framework, this paper contributes to clinical pedagogy and educational philosophy by clarifying the significance of practice-based judgement and expanding the conceptual horizon of educational transformation beyond reflective understanding
メタン発酵消化液の利用が異なる土壌条件において作物と窒素の消長に与える影響
No full text京都大学新制・課程博士博士(地球環境学)甲第26419号地環博第285号京都大学大学院地球環境学舎地球環境学専攻(主査)教授 真常 仁志, 教授 田中 千尋, 准教授 小林 優学位規則第4条第1項該当Doctor of Global Environmental StudiesKyoto UniversityDFA
Long-term outcome of PDT for local failure after CRT or RT for oesophageal cancer
No full text: The long-term local control and effect of photodynamic therapy (PDT) using talaporfin sodium and a diode laser (talaporfin PDT) on overall survival (OS) for local failure after chemoradiotherapy (CRT) for esophageal cancer are unknown. Here, we present a 5-year survival analysis for talaporfin PDT. : This was a prospective follow-up analysis of an open-label, multicenter, phase 2 study of local failure after CRT or radiotherapy in patients who received talaporfin PDT. The primary endpoint was the overall OS. The secondary endpoints were progression-free survival (PFS), local progression-free survival (L-PFS) with local progression or recurrence and death as events, and local time to progression (L-TTP) with only local progression or recurrence as events. : Between November 2012 and December 2013, 26 patients with oesophageal squamous cell carcinoma underwent talaporfin PDT. The baseline T stages were cT1 in 14 patients, cT2 in 6 patients, and cT3 in 6 patients. Pre-PDT T stages were cT1b for 19 and cT2 for 7 patients, and no lymph nodes or distant metastases were detected. At a median 6.8-year follow-up, the median OS and 5-year OS rates were 4.2 years (95% confidence interval [CI]: 1.6-7.3) and 40.6% (95% CI: 21.7-58.7), respectively. The median PFS and L-PFS were 1.1 and 2.1 years, respectively. The 5-year local progression-free rate was 84.9%. No treatment-related deaths occurred. : Talaporfin PDT for patients with oesophageal cancer with local failure after CRT can achieve long-term local complete response and long-term survival as a minimally invasive salvage treatment. : UMIN000009184
Development of a non-destructive elemental analysis method for sub-percent components using muon-induced gamma-rays
No full textA new non-destructive elemental analysis method using muon-induced gamma-rays was developed to quantify sub-percent components in bulk materials, including light elements. Pulsed muon beam irradiation experiments for iron reference samples containing varying silicon concentrations were conducted to demonstrate the method. Characteristic muonic X-rays and gamma-rays emitted from unstable nuclides generated by muon nuclear absorption were measured using germanium detectors during the beam irradiation. By measuring gamma-rays derived from silicon, we successfully quantified the silicon at a concentration of 0.36 wt.% in the bulk iron sample, which is difficult to detect using conventional muon elemental analysis based solely on X-rays
Visible light-driven hydrogen evolution using dye-semiconductor hybrids: effects of peripheral substituents and central metals of chlorophyll- derivatives as photosensitizers
No full textChlorophyll (Chl)- derivatives possessing a carboxylated substituent at the peripheral 20-position were prepared as photosensitizers. The synthetic pigments were adsorbed onto the surface of titanium oxide particles loaded with platinum nanoparticles through the bonding of the carboxy group of the Chls with the oxygen functional groups of TiO₂. In an aqueous ascorbic acid solution, the resulting Chl-attaching Pt-TiO₂ was illuminated with orange and red light to generate hydrogen gas. The hydrogen evolution reaction was initiated by the electron injection of the Chl photosensitizers excited with the visible light to the TiO₂ semiconductor and was completed by the reduction of aqueous protons into H₂ on the Pt cocatalyst, while ascorbic acid functioned as an electron donor to the Chl species. The hydrogen evolution activity was dependent on the spacer between the core chlorin π-system and the terminal carboxy group in the Chls. An increase in the spacer length suppressed the undesired back electron transfer from the TiO₂ surface to the Chl cation radical to enhance the amount of evolved H₂. The facile insertion of a copper atom at the central position of a Chl sensitizer boosted the photocatalytic activity, but its zincation and nickelation diminished the photosensitizing abilities
シスチン/グルタミン酸輸送体を介したグルタチオン合成は腎臓三次リンパ組織形成を促進する
No full text京都大学新制・論文博士博士(医学)乙第13732号論医博第2369号京都大学大学院医学研究科医学専攻(主査)教授 竹内 理, 教授 上野 英樹, 教授 濵﨑 洋子学位規則第4条第2項該当Doctor of Medical ScienceKyoto UniversityDFA