A Sillén Oxyhalide SrBi₃O₄Cl₃ as a Promising Photocatalyst for Water Splitting: Impact of the Asymmetric Structure on Light Absorption and Charge Carrier Dynamics

Bismuth-based oxyhalides with layered Sillén(–Aurivillius) structures have attracted significant attention as photocatalysts. Recent studies have unveiled a part of the structure–property relationship of the materials; however, it has not been fully understood. In the present study, we investigated a Sillén-type oxyhalide SrBi₃O₄Cl₃ with single and double halogen layers. Interestingly, SrBi₃O₄Cl₃ showed a visible light response up to ∼460 nm, whereas SrBiO₂Cl and BiOCl with single and double halogen layers, respectively, did not. Rietveld refinement and STEM-EDX mapping determined the asymmetric Bi occupation in the fluorite [Sr₀.₅Bi₁.₅O₂] layer of SrBi₃O₄Cl₃, which was derived from the coexistence of the halogen layers. DFT calculations and Madelung potential calculations showed that the asymmetric Bi occupation affords both the Bi–Bi interaction across the single halogen layer and the electrostatic destabilization of Cl in the double halogen layer, probably leading to the narrow bandgap of SrBi₃O₄Cl₃. Another merit of possessing the two different halogen layers was revealed by time-resolved microwave conductivity measurements as well as DFT calculations; the spatial separation of the conduction band minimum and valence band maximum based on the coexistence of the halogen layers would promote charge carrier separation. Visible-light-driven Z-scheme water splitting was accomplished using a RuO₂-loaded SrBi₃O₄Cl₃ sample as an O₂-evolving photocatalyst. This study provides another option for engineering band structures and promoting the charge carrier separation of layered oxyhalides for efficient water splitting under visible light

A study on curriculum development for indirect proof: understanding and constructing the process of proof by contradiction

本研究の目的は，間接証明に関するカリキュラムの開発である。その狙いは，十分に理解されていないと考えられる間接証明をよりよく学ぶと共に，学びの過程を通して論理を扱う能力を育むことである。本稿においては，その基礎として，間接証明を学ぶ過程を明らかにすることを目的とした。ただし，間接証明が何かという統一見解は見られないため，今回は背理法に限定して考察した。 目的のため，まず背理法に関する知識を分析し，特に数学史を参照しながら，背理法を構成することが期待される学習を設計した（アプリオリ分析）。高等学校1年生に授業を実施した結果，生徒の実態を十分想定出来ていなかったことから，学習自体は十分に成功しなかった。しかしながら，背理法に関する知識の分析それ自体については，かなりの部分が妥当であることは示された。本時の課題を元に，改善した学習を実施することで，知識の分析の妥当性や限界を明らかにし，カリキュラム開発に繋げることが今後の課題である。The purpose of our study is to develop a curriculum of indirect proof. It aims to increase students’ understanding about indirect proof, and to improve their ability to use logic. Furthermore, we aim to construct a process of indirect proof, as the base of the curriculum. However, as there is no consensus regarding the definition of indirect proof, we only consider proof by contradiction. For this purpose, we designed a lesson in which students will probably be knowing indirect proof and then construct a process of the proof based on their conception (a priori analysis). We conducted the lesson in a 10th grade mathematics class. However, the lesson was not as successful as expected because we overestimated the students’ actual level of cognition. In contrast, most of our analysis of the knowledge is validated. Our future task is to design an improved lesson to deliver to students. We would also need to clarify the validation and limitations of our analysis

A comparison of nephrotoxicity between patients with a solitary-functioning kidney and those with bilateral-functioning kidneys in cisplatin-based chemotherapy for advanced urothelial carcinoma: a Japanese retrospective multi-institutional study

BackgroundTo compare the prevalence of nephrotoxicity between patients with a solitary-functioning kidney versus those with bilateral-functioning kidneys during the administration of cisplatin-based chemotherapy for advanced urothelial carcinoma.MethodsWe retrospectively analyzed 244 advanced urothelial carcinoma patients treated with cisplatin-based chemotherapy between 2004 and 2010 at 17 institutes in Japan. The 24 h creatinine clearance, Cockcroft–Gault formula, and estimated glomerular filtration rate equation (eGFR), were compared before all chemotherapies. The urinary tract function status was determined based on the data of nephroureterectomy, hydronephrosis, and relief of upper urinary tract obstruction. A total of 244 patients were divided into four groups according to their urinary tract functioning status and eGFR results, including bilateral-functioning kidneys with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 83, 34.0%); a solitary-functioning kidney with pretreatment eGFR ≥60 mL/min/1.73 m2 group (n = 36, 14.8%); bilateral-functioning kidneys with pretreatment eGFR  10% and 30% from baseline in the post-third-course of chemotherapy was significantly higher in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney, among patients with pretreatment eGFR  20% from baseline were significantly higher in patients with bilateral-functioning kidneys than those with a solitary-functioning kidney among patients with pretreatment eGFR < 60 mL/min/1.73 m2 (p = 0.034), whereas no significant difference was observed among patients with pretreatment eGFR ≥60 mL/min/1.73 m2.ConclusionsThe results suggest that cisplatin-based chemotherapy may have more nephrotoxicity in patients with bilateral-functioning kidneys than in those with a solitary-functioning kidney

歯科用CTを用いた解剖学的下顎頭運動の多点解析

The aim of this study was to develop a method for integrating morphological coordinates obtained with dental computer tomography (CT) and jaw movement coordinates acquired with a mandibular movement measuring device in order to enable multipoint analysis of anatomical condylar movements to be performed. The study subjects were two volunteers. One of the subjects displayed mandibular deviation and had a deformed condyle (on the deviated side), while the other subject exhibited normal occlusion and had healthy condyles. We placed three lead markers in front of each of the subjectsʼ ears and used them to integrate dental CT–derived morphological volume data and jaw movement data, both of which were obtained while the subjects were in the same seated position. Regarding the reproducibility of the reference point data, the positioning and orientation data obtained with the condylar movement measurement system exhibited maximum standard deviation values of 0.162 mm and 0.0₇4°, respectively, while the equivalent data acquired with the CT coordinate system displayed maximum standard deviation values of 0.068 mm and 0.00₇°, respectively. This suggested that reference point errors had little effect on our multipoint analysis of anatomical condylar movement and that the method used to transform the CT coordinates was highly precise. These results indicate that our method for integrating dental CT–derived coordinates with those acquired using a condylar movement measuring device leads to minimal errors in the positional/rotational data for the reference markers and hence, facilitates multipoint analyses of anatomical condylar movement

A mitochondrial origin for frontotemporal dementia and amyotrophic lateral sclerosis through CHCHD10 involvement.

Mitochondrial DNA instability disorders are responsible for a large clinical spectrum, among which amyotrophic lateral sclerosis-like symptoms and frontotemporal dementia are extremely rare. We report a large family with a late-onset phenotype including motor neuron disease, cognitive decline resembling frontotemporal dementia, cerebellar ataxia and myopathy. In all patients, muscle biopsy showed ragged-red and cytochrome c oxidase-negative fibres with combined respiratory chain deficiency and abnormal assembly of complex V. The multiple mitochondrial DNA deletions found in skeletal muscle revealed a mitochondrial DNA instability disorder. Patient fibroblasts present with respiratory chain deficiency, mitochondrial ultrastructural alterations and fragmentation of the mitochondrial network. Interestingly, expression of matrix-targeted photoactivatable GFP showed that mitochondrial fusion was not inhibited in patient fibroblasts. Using whole-exome sequencing we identified a missense mutation (c.176C>T; p.Ser59Leu) in the CHCHD10 gene that encodes a coiled-coil helix coiled-coil helix protein, whose function is unknown. We show that CHCHD10 is a mitochondrial protein located in the intermembrane space and enriched at cristae junctions. Overexpression of a CHCHD10 mutant allele in HeLa cells led to fragmentation of the mitochondrial network and ultrastructural major abnormalities including loss, disorganization and dilatation of cristae. The observation of a frontotemporal dementia-amyotrophic lateral sclerosis phenotype in a mitochondrial disease led us to analyse CHCHD10 in a cohort of 21 families with pathologically proven frontotemporal dementia-amyotrophic lateral sclerosis. We identified the same missense p.Ser59Leu mutation in one of these families. This work opens a novel field to explore the pathogenesis of the frontotemporal dementia-amyotrophic lateral sclerosis clinical spectrum by showing that mitochondrial disease may be at the origin of some of these phenotypes

Anti-retroviral drug resistance-associated mutations among non-subtype B HIV-1-infected Kenyan children with treatment failure

金沢大学大学院医学系研究科感染症制御学Recently increased availability of antiretroviral therapy (ART) has mitigated HIV-1/AIDS prognoses especially in resource poor settings. The emergence of ART resistance-associated mutations from non-suppressive ART has been implicated as a major cause of ART failure. Reverse transcriptase inhibitor (RTI)-resistance mutations among 12 non-subtype B HIV-1-infected children with treatment failure were evaluated by genotypically analyzing HIV-1 strains isolated from plasma obtained between 2001 and 2004. A region of pol-RT gene was amplified and at least five clones per sample were analyzed. Phylogenetic analysis revealed HIV-1 subtype A1 (n = 7), subtype C (n = 1), subtype D (n = 3), and CRF02_AG (n = 1). Before treatment, 4 of 12 (33.3%) children had primary RTI-resistance mutations, K103N (n = 3, ages 5-7 years) and Y181C (n = 1, age 1 year). In one child, K103N was found as a minor population (1/5 clones) before treatment and became major (7/7 clones) 8 months after RTI treatment. In 7 of 12 children, M184V appeared with one thymidine-analogue-associated mutation (TAM) as the first mutation, while the remaining 5 children had only TAMs appearing either individually (n = 2), or as TAMs 1 (M41L, L210W, and T215Y) and 2 (D67N, K70R, and K219Q/E/R) appearing together (n = 3). These results suggest that "vertically transmitted" primary RTI-resistance mutations, K103N and Y181C, can persist over the years even in the absence of drug pressure and impact RTI treatment negatively, and that appearing patterns of RTI-resistance mutations among non-subtype B HIV-1-infected children could possibly be different from those reported in subtype B-infected children. © 2007 Wiley-Liss, Inc

Immunohistochemical Analysis of Mitochondrial Ferritin in the Midbrain of Patients with Parkinson\u27s Disease

Mitochondrial ferritin (FtMt) is an endogenous iron-storage protein localized in the mitochondria. FtMt is mainly observed in restricted tissues, such as those in the testis, islets of Langerhans, and brain. Further, it may protect cells from oxidative stress in neurodegenerative diseases, including Alzheimer\u27s disease and progressive supranuclear palsy. However, the role of FtMt in Parkinson\u27s disease (PD) remains unclear. Therefore, the current study investigated the localization and expression level of FtMt in the midbrain of patients with PD and healthy controls using immunohistochemical techniques. FtMt immunoreactivity was mainly detected in dopaminergic neurons in the substantia nigra pars compacta (SNc) in both healthy controls and patients with PD. In addition, FtMt-positive particles were observed outside the dopaminergic neurons in patients with PD. Based on a quantitative comparison, patients with PD had a significantly upregulated FtMt immunoreactivity in dopaminergic neurons than healthy controls. Our result might be helpful in future studies on the role of FtMt in PD

Visualization of Amyloid Oligomers in the Brain of Patients with Alzheimer's Disease

In the pathogenesis of Alzheimer's disease (AD), highly neurotoxic amyloid-β (Aβ) oligomers appear early, they are thus considered to be deeply involved in the onset of Alzheimer's disease. However, Aβ oligomer visualization is challenging in human tissues due to their multiple forms (e.g., low- and high-molecular-weight oligomers, including protofibrils) as well as their tendency to rapidly change forms and aggregate. In this review, we present two visualization approaches for Aβ oligomers in tissues: an immunohistochemical (using the monoclonal antibody TxCo1 against toxic Aβ oligomer conformers) and imaging mass spectrometry using the small chemical Shiga-Y51 that specifically binds Aβ oligomers. TxCo1 immunohistochemistry revealed Aβ oligomer distributions in postmortem human brains with AD. Using Shiga-Y51, imaging mass spectrometry revealed Aβ oligomer distributions in the brain of a transgenic mouse model for AD. These two methods would potentially contribute to elucidating the pathological mechanisms underlying AD.journal articl