102 research outputs found
The Intensity of Satellite Reflections in Electron Diffraction Patterns from Evaporated Alloy Films with CuAu II Type Superstructure
In order to elucidate the origin of satellite reflections flanking the direct spot in the electron diffraction pattern of a single crystal evaporated film with CuAu II type superlattice, the peak as well as integrated intensities have been measured as functions of the wavelength of electrons corresponding to the accelerating voltage from 75 to 280KV. It has been revealed that the intensity of the satellite in question relative to a fundamental reflection consists of two parts, a major part which depends on the wavelength in such a way as predicted by the theory of multiple reflection, and the other minor part which is independent of the wavelength. The existence of the latter part shows that the reflection is not a forbidden one and, therefore, a lattice modulation accompanies the regular anti-phase structure. Fourier potential due to this lattice modulation, V_s, is estimated to be in the order of one tenth the magnitude of V_ Some consideration concerning the nature of the modulation is given by comparing the results of electron and X-ray diffraction studies
Astrocytic dysfunction induced by ABCA1 deficiency causes optic neuropathy
Astrocyte abnormalities have received great attention for their association with various diseases in the brain but not so much in the eye. Recent independent genome-wide association studies of glaucoma, optic neuropathy characterized by retinal ganglion cell (RGC) degeneration, and vision loss found that single-nucleotide polymorphisms near the ABCA1 locus were common risk factors. Here, we show that Abca1 loss in retinal astrocytes causes glaucoma-like optic neuropathy in aged mice. ABCA1 was highly expressed in retinal astrocytes in mice. Thus, we generated macroglia-specific Abca1-deficient mice (Glia-KO) and found that aged Glia-KO mice had RGC degeneration and ocular dysfunction without affected intraocular pressure, a conventional risk factor for glaucoma. Single-cell RNA sequencing revealed that Abca1 deficiency in aged Glia-KO mice caused astrocyte-triggered inflammation and increased the susceptibility of certain RGC clusters to excitotoxicity. Together, astrocytes play a pivotal role in eye diseases, and loss of ABCA1 in astrocytes causes glaucoma-like neuropathy
Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP
細胞膜の中ではたらく特殊なタンパク質分解酵素の構造を解明 --細菌感染症の新たな治療法の開発へ期待--. 京都大学プレスリリース. 2022-08-25.Site-2 proteases are a conserved family of intramembrane proteases that cleave transmembrane substrates to regulate signal transduction and maintain proteostasis. Here, we elucidated crystal structures of inhibitor-bound forms of bacterial site-2 proteases including Escherichia coli RseP. Structure-based chemical modification and cross-linking experiments indicated that the RseP domains surrounding the active center undergo conformational changes to expose the substrate-binding site, suggesting that RseP has a gating mechanism to regulate substrate entry. Furthermore, mutational analysis suggests that a conserved electrostatic linkage between the transmembrane and peripheral membrane-associated domains mediates the conformational changes. In vivo cleavage assays also support that the substrate transmembrane helix is unwound by strand addition to the intramembrane β sheet of RseP and is clamped by a conserved asparagine residue at the active center for efficient cleavage. This mechanism underlying the substrate binding, i.e., unwinding and clamping, appears common across distinct families of intramembrane proteases that cleave transmembrane segments
Borehole measurement of deep ice coring site at Dome Fuji, Antarctica and characteristics of basal ice near bedrock
第2回極域科学シンポジウム 氷床コアセッション 11月16日(水) 国立極地研究所 2階大会議室前フロ
The Creation of School Education Bringing up a Student Carrying Tomorrow (3) : The Valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects"
The purpose of this study is to show the valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects", to show the relationship between each subjects and "three abilities", "the ability of recognizing othere senses of value", "the ability of self-expression and communication" and "the ability of decision-making" which defined by the project members. The main result of this study is that we should make up the standards which teachers, students and parents recognize as important abilities
Differentiation of multipotent neural stem cells derived from Rett syndrome patients is biased toward the astrocytic lineage
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