177 research outputs found
Development of Helical Myofiber Tracts in the Human Fetal Heart: Analysis of Myocardial Fiber Formation in the Left Ventricle From the Late Human Embryonic Period Using Diffusion Tensor Magnetic Resonance Imaging
ヒト胎児心臓の心筋線維方向を追跡 --受精後8週の心筋線維は成人と同じ配列をする--. 京都大学プレスリリース. 2020-10-09.Background: Detection of the fiber orientation pattern of the myocardium using diffusion tensor magnetic resonance imaging lags ≈12 weeks of gestational age (WGA) behind fetal myocardial remodeling with invasion by the developing coronary vasculature (8 WGA). We aimed to use diffusion tensor magnetic resonance imaging tractography to characterize the evolution of fiber architecture in the developing human heart from the later embryonic period. Methods and Results: Twenty human specimens (8–24 WGA) from the Kyoto Collection of Human Embryos and Fetuses, including specimens from the embryonic period (Carnegie stages 20–23), were used. Diffusion tensor magnetic resonance imaging data were acquired with a 7T magnetic resonance system. Fractional anisotropy and helix angle were calculated using standard definitions. In all samples, the fibers ran helically in an organized pattern in both the left and right ventricles. A smooth transmural change in helix angle values (from positive to negative) was detected in all 16 directions of the ventricles. This feature was observed in almost all small (Carnegie stage 23) and large samples. A higher fractional anisotropy value was detected at the outer side of the anterior wall and septum at Carnegie stage 20 to 22, which spread around the ventricular wall at Carnegie stage 23 and in the early fetal samples (11–12 WGA). The fractional anisotropy value of the left ventricular walls decreased in samples with ≥13 WGA, which remained low (≈0.09) in larger samples. Conclusions: From the human late embryonic period (from 8 WGA), the helix angle arrangement of the myocardium is comparable to that of the adult, indicating that the myocardial structure blueprint, organization, and integrity are already formed
Nucleophilic Substitution Reaction in Indole Chemistry: 1-Methoxy-6-nitroindole-3-carbaldehyde as a Versatile Building Block for 2,3,6-Trisubstituted Indoles
金沢大学医薬保健研究域薬学系金沢大学名誉教
Nucleophilic substitution reaction in indole chemistry: 1-methoxy-6-nitroindole-3-carbaldehyde as a versatile building block for 2,3,6-trisubstituted indoles
1-Methoxy-6-nitroindole-3-carbaldehyde is proved to be a versatile electrophile and reacts regioselectively at the 2-position with various types of nucleophiles providing 2,3,6-trisubstituted indole derivatives. The reaction is applicable for the preparation of a novel pyrimido[1,2-a]indole derivative. © 2009 The Japan Institute of Heterocyclic Chemistry All rights reserved
Nucleophilic substitution reactions of 1-methoxy-6-nitroindole-3-carbaldehyde 1
金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部1-Methoxy-6-nitroindole-3-carbaldehyde is proved to be a versatile substrate for the nucleophilic substitution reactions providing 2,3,6-trisubstituted indole derivatives. Preparation of a novel pyrimido[1,2-a]indole derivative is also reported
Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography
Purpose: To evaluate the clinical feasibility of peripheral chorioretinal imaging through a front prism on swept-source optical coherence tomography angiography (SS-OCTA). Methods: We prospectively obtained en face OCTA images using SS-OCTA in 10 eyes of 10 healthy volunteers. For the peripheral chorioretinal imaging, the scanning laser passed and refracted through a 45 −90 −45 right-angle prism. We evaluated the qualitative and quantitative characteristics of chorioretinal vessels in the periphery. Results: Using peripheral chorioretinal imaging through a prism, the retinal vasculature was delineated to the equator on the OCTA images, and varices of the vortex vein ampullae were observed on choroidal OCT images. The 3×3-mm images revealed three-dimensional morphologies unique to the peripheral vasculature, such as the gap between retinal arterioles and venules in the superficial capillary plexus (SCP) and elliptical and greater lobules in the choriocapillaris layer. Compared with OCTA images obtained without the prism, those obtained through the prism demonstrated an approximately 1.24-fold increase in the lengths in the base apex direction, whereas the lengths in the perpendicular direction showed concordance. The peripheral vessel density (VD) in the inferior quadrant was lower than those in the other quadrants on the SCP and deep capillary plexus, whereas on the SCP images of the macula the lowest VD was observed in the temporal subfield. Conclusions: Peripheral chorioretinal imaging allowed us to generate ultra-widefield panoramic OCTA images and demonstrated morphologic characteristics unique to peripheral chorioretinal vessels. Translational Relevance: OCTA imaging through a front prism can be a technique for acquiring chorioretinal vasculature images in the periphery
Synthesis of analogs of wasabi phytoalexin (methyl 1-methoxyindole-3-carboxylate)
金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部Syntheses of wasabi phytoalexin analogs, such as 6-bromo-5-iodo, 2-bromo-5-iodo, 6-nitro, 5-chloroacetyl, and 6-chloroacetyl congeners, are reported. An interesting effect of the 1-methoxy group on the regioselectivity of electrophilic substitution reactions on indole nucleus is observed
Novel syntheses of 1-hydroxy-6- and -5-nitroindole-3-carbaldehydes, and their derivatives as daikon-phytoalexin analogs
金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部1-Hydroxy-6- and -5-nitroindole-3-carbaldehydes are prepared for the first time from 1-methoxy-6- and -5-nitroindole-3-carbaldehydes, respectively, based on the discovery of novel methyl ether cleavage reaction. Utilizing them as common synthetic intermediates, syntheses of several daikon-phytoalexin analogs are achieved
High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant Puppis A with the XMM-Newton RGS
We present high-resolution X-ray spectra of cloud-shock interaction regions in the eastern and northern rims of the Galactic supernova remnant Puppis A, using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A number of emission lines including K(alpha) triplets of He-like N, O , and Ne are clearly resolved for the first time. Intensity ratios of forbidden to resonance lines in the triplets are found to be higher than predictions by thermal emission models having plausible plasma parameters. The anomalous line ratios cannot be reproduced by effects of resonance scattering, recombination, or inner-shell ionization processes, but could be explained by charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. Our observations thus provide observational support for charge-exchange X-ray emission in supernova remnants
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