2,144 research outputs found

    Measurements of stratospheric ozone by rocket ozonesondes in Japan

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    A small optical ozone instrument has been developed for a rocket-borne dropsonde to measure the altitude profile of stratospheric ozone. It consists of a four-color filter photometer that measures the attenuation of sunlight as a function of altitude at four wavelengths in the middle ultraviolet. The ozone dropsonde is launched aboard a meteorological rocket MT-135, providing the altitude profiles of ozone as well as atmospheric temperature and wind. The rocket launchings have been carried out five times since August 1990 at Uchinoura (31 deg N, 131 deg E), Japan to measure ozone concentration from 52 to 20 km altitudes during the slow fall of the dropsonde. The ozone profiles measured in summer (August 27, 1990; Sep. 11 and 12, 1991) were very stable above an altitude of 28km. where as those measured in winter (Feb. 9, and 11, 1991) showed considerable day-to-day variations at the stratospheric altitudes. Ozone, temperature and wind profiles measured simultaneously by both rocket and balloon ozonsondes are compared with CIRA 1986 model atmosphere

    Cell differentiation and development

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    The development of organoid techniques for regenerative therapy has progressed remarkably with the use of tissue-derived stem cells and pluripotent stem cells based on stem cell biology and tissue engineering technology. To realize whole-organ replacement therapy as next-generation regenerative medicine, it is expected that fully functional bioengineered organs can be reconstructed using an in vitro three-dimensional (3D) bioengineered organ germ and organoids by stem cell manipulation and self-organization. In this mini-review, we focused on substantial advances of 3D bioengineering technologies for the regeneration of complex oral organs with the reconstruction of 3D bioengineered organ germ using organ-inductive potential embryo-derived epithelial and mesenchymal cells. These bioengineering technologies have the potential for realization of future organ replacement therapy

    Analysis of A-Type and B-Type Highly Polymeric Proanthocyanidins and Their Biological Activities as Nutraceuticals

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    Proanthocyanidins have a series of heteroflavan-3-ols, (+)-catechin/(−)-epicatechin units, which are linked through a single B-type linkage and a doubly linked A-type linkage. Recently, we have performed the structural characterization of seed shells of the Japanese horse chestnut and fruits of blueberry and cranberry. The molecular sizes of them were higher in the order of blueberry > cranberry > seed shells of the Japanese horse chestnut between the respective fractions. For the analysis of terminal and extension units in those proanthocyanidins, the isolated fractions were subjected to the thiolytic cleavage of the B-type linkages using 1-dodecanethiol, and the resulting degradation products were identified by ultraperformance liquid chromatography coupled with electrospray-ionization mass spectrometry. These analyses provided fast and good resolution of the degradation products and revealed higher proportions of A-type linkages compared with B-type linkages in both isolated fractions in the order of the seed shells > cranberry > blueberry. Moreover, the isolated fractions with higher molecular sizes and those more abundant in the proportions of A-type linkages were found to be more effective in the inhibition of pancreatic lipase activity. The results suggest that A-type highly polymeric proanthocyanidins are promising for the attenuation of lipid digestion as dietary supplements

    High-resolution simulation of propagation of interplanetary shock wave caused by a coronal mass ejection observed on November 13, 2003

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    We simulated the three-dimensional (3D) propagation of a shock wave caused by a coronal mass ejection (CME) on November 13, 2003. The 3D simulations were performed using a high-resolution adaptive mesh refinement (AMR) technique. The AMR technique enabled us to resolve near the sun with (0.06R_◎)^3-sized cells and to resolve the entire shock front with (0.24R_◎)^3-sized cells in an interplanetary simulation within a (500R_◎)^3-sized computational box. The solar wind was measured by an imaginary spacecraft positioned at point L1 in the simulations. A model fitted for solar wind density fluctuations observed by the ACE spacecraft was employed, and models in which some CME parameters were changed were employed for comparison. The relationships between the CME parameters and the solar wind fluctuations were also investigated, and the results were compared with the solar wind data observed at point L1 by the ACE spacecraft

    Wedge holography in flat space and celestial holography

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    In this paper, we study codimension two holography in flat spacetimes, based on the idea of the wedge holography. We propose that a region in a d+1 dimensional flat spacetime surrounded by two end of the world branes, which are given by d dimensional hyperbolic spaces, is dual to a conformal field theory (CFT) on a d-1 dimensional sphere. Similarly, we also propose that a d+1 dimensional region in the flat spacetime bounded by two d dimensional de Sitter spaces is holographically dual to a CFT on a d-1 dimensional sphere. Our calculations of the partition function, holographic entanglement entropy and two point functions, support these duality relations and imply that such CFTs are nonunitary. Finally, we glue these two dualities along null surfaces to realize a codimension two holography for a full Minkowski spacetime and discuss a possible connection to the celestial holography

    Gliding Basal Cell Migration of the Urothelium during Wound Healing

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    Collective cell migration during wound healing has been extensively studied in the epidermis. However, it remains unknown whether the urothelium repairs wounds in a manner similar to the epidermis. By in vivo two-photon excitation microscopy of transgenic mice that express fluorescent biosensors, we studied the collective cell migration of the urothelium in comparison with that of the epidermis. In vivo time-lapse imaging revealed that, even in the absence of a wound, urothelial cells continuously moved and sometimes glided as a sheet over the underlying lamina propria. On abrasion of the epithelium, the migration speed of each epidermal cell was inversely correlated with the distance to the wound edge. Repetitive activation waves of extracellular signal–regulated kinase (ERK) were generated at and propagated away from the wound edge. In contrast, urothelial cells glided as a sheet over the lamina propria without any ERK activation waves. Accordingly, the mitogen-activated protein kinase/ERK kinase inhibitor PD0325901 decreased the migration velocity of the epidermis but not the urothelium. Interestingly, the tyrosine kinase inhibitor dasatinib inhibited migration of the urothelium as well as the epidermis, suggesting that the gliding migration of the urothelium is an active, not a passive, migration. In conclusion, the urothelium glides over the lamina propria to fill wounds in an ERK-independent manner, whereas the epidermis crawls to cover wounds in an ERK-dependent manner

    Attenuation of Immune-Mediated Renal Injury by Telmisartan, an Angiotensin Receptor Blocker and a Selective PPAR-γ Activator

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    Background/Aims: Anti-glomerular basement membrane (GBM) nephritis is characterized by activation of the renin-angiotensin system. This study aimed to determine the question of whether a temporary angiotensin II blockade at the initial stage of anti-GBM nephritis is able to attenuate the disease as well as differences in renoprotection among angiotensin II receptor blockers (ARBs) with distinct peroxisome proliferator-activated receptor (PPAR)-γ-modulating activities. Methods: C57BL/6J mice were immunized with rabbit IgG, followed by intravenous injection of rabbit anti-mouse antibodies. Mice were then treated with telmisartan, losartan, and telmisartan + GW9662 (a PPAR-γ antagonist) for 5 days, or hydralazine for 9 days. On days 8 and 13, mice were sacrificed to obtain tissues for histological analysis. Results: The temporary administration of telmisartan significantly suppressed glomerular damage compared to hydralazine. Losartan showed a similar effect but was less effective. Co-administration of GW9662 attenuated the renoprotective effect of telmisartan, almost to levels observed with losartan. In particular, it limited the decreased infiltration of inflammatory cells and preservation of capillaries in the glomeruli induced by telmisartan. Conclusion: Temporary angiotensin II blockade at the initial stage of anti-GBM disease dramatically inhibited its progression. In addition to a class effect of ARBs, telmisartan modified inflammation and endothelial damage in the kidney through its PPAR-γ-agonistic action
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