144 research outputs found

    Analysis of leukocyte rolling and migration--using inhibitors in the undisturbed microcirculation of the rat mesentery--on inflammatory stimulation.

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    AIM: Our aim was to develop a method of migration analysis using the undisturbed microcirculation of rat mesentery, and using the new method, analyze leukocyte migration in casein-induced inflammation. METHOD: Sprague Dawley (SD) rats were injected with tumor necrosis factor (TNF) alpha, interleukin (IL)-1alpha, or casein intraperitoneally. Following this, the rats were sacrificed and the mesentery tissue removed was fixed and stained with Giemsa. The leukocytes were counted as a rolling index in the venules and as a migration index in the perivascular area. RESULTS: There was no relation between the diameter of venules and leukocyte migration. The time change curves of leukocyte activity in casein inflammation show about a 1 h difference between rolling and migration. From inhibitor experiments of casein-induced migration at 2 h, it has been suggested that selectin-related rolling is necessary. Platelet-activating factor (PAF) also appears partially involved. CONCLUSION: The improved undisturbed microcirculation method is helpful not only for rolling analysis but also in analysis of leukocyte migration. Casein inflammation analyzed using this method revealed that rolling is necessary and also suggested that partial involvement of PAF is necessary for pathogenesis of leukocyte extravasations


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    The demand for electricity has rapidly risen in rural Tanzania due to the spread of mobile phones. In a rural village in southern Tanzania, we collaborated with a group of villagers to develop a pico-hydro system with a screw turbine and introduced it to a flat plateau with a low water head. The power generation system was designed to take advantage of the fluvial environment and gentle slopes to counteract the drastic changes in water level that can occur throughout Africa. The project began in 2010 with a pico-hydro system using a traditional Japanese screw turbine, resulting in successful power generation in 2012. This study clarified key considerations in developing a community-based pico-hydro system. Low cost, locally sourced materials and equipment are advantageous. A lightweight screw turbine power generation system is transportable to meet changing water levels. Easy reproduction and/or modification can meet changing needs. The proposed system could provide stable electrical power for lights and mobile phones. Additionally, the cooperative exchange promoted by the project inspired the local people to create their own environmental groups to take on activities that supported sustainable natural resource use

    Frequency ratios of Sr, Yb and Hg based optical lattice clocks and their applications

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    This article describes the recent progress of optical lattice clocks with neutral strontium (87^{87}Sr), ytterbium (171^{171}Yb) and mercury (199^{199}Hg) atoms. In particular, we present frequency comparison between the clocks locally via an optical frequency comb and between two Sr clocks at remote sites using a phase-stabilized fibre link. We first review cryogenic Sr optical lattice clocks that reduce the room-temperature blackbody radiation shift by two orders of magnitude and serve as a reference in the following clock comparisons. Similar physical properties of Sr and Yb atoms, such as transition wavelengths and vapour pressure, have allowed our development of a compatible clock for both species. A cryogenic Yb clock is evaluated by referencing a Sr clock. We also report on a Hg clock, which shows one order of magnitude less sensitivity to blackbody radiation, while its large nuclear charge makes the clock sensitive to the variation of fine-structure constant. Connecting all three types of clocks by an optical frequency comb, the ratios of the clock frequencies are determined with uncertainties smaller than possible through absolute frequency measurements. Finally, we describe a synchronous frequency comparison between two Sr-based remote clocks over a distance of 15 km between RIKEN and the University of Tokyo, as a step towards relativistic geodesy.Comment: 11 pages, 5 figures, invited review article in Comptes Rendus de Physique 201

    Phytochrome-regulated EBL1 contributes to ACO1 upregulation in rice

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    The 1-aminocyclopropane-1-carboxylate oxidase gene (ACO1) was upregulated in rice (Oryza sativa L.) phyAphyBphyC mutants lacking any phytochrome and containing the GCC box element, a binding site for rice ethylene-responsive element binding protein 1 (OsEREBP1), in its promoter region. Since the OsEREBP1-like gene EBL1 (OsEREBP1-LIKE 1) was significantly downregulated in phyAphyBphyC mutants, EBL1 was suspected to repress ACO1 expression in wild-type plants. However, ACO1 was downregulated in EBL1 RNA interference plants, and the total length of these plants was slightly shorter than that of wild-type plants. This study shows that EBL1 is positively regulated by phytochrome B and associated with ACO1 upregulation

    NMR-metabolomics revealed metabolites and bioactivity variation in Torbangun leaves (Plectranthus amboinicus L.) of different origin

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    Plectranthus amboinicus (PA) were previously reported to have antidiabetic and antioxidant activities. Environmental factors might influence the plant’s  secondary metabolite profile and their health beneficial properties. NMR-metabolomics was used to show phytochemicals variation between the Plectranthus ambonicus grown in Japan and that grown in Indonesia. The results showed that flavonoids and triterpenes were among discriminating factors of the variation between the two groups. Targeted comparative analysis of the concentration of the specific flavonoids of the plants using a validated HPLC-MWD method showed that Japanese samples contained higher concentration of total flavonoids than that of Indonesian samples. The Japanese and Indonesian samples contained 1100.6 ± 5.1 and 532.4 ± 1.8 µg/g  luteolin , 584.5 ± 7.4 and 571.7 ± 11.6 µg/g  apigenin, respectively. Eriodyctiol was detected only in Indonesian samples. Contrarily, more intensive DPPH reduction and α-glucosidase inhibition activities were found in the  Indonesian samples (IC50 14.4 ± 1.2 and 24.0 ± 0.3 µg/mL for the DPPH assay, 1181.9 ± 113.5 and 4451.4 ± 290.0 µg/mL for α-glucosidase inhibition, respectively). Thus, the flavonoids might not the only group of compounds related to the bioactivity, but it should be confirmed  by further research targetting other groups of compounds such as triterpenes

    Direct Comparison of Distant Optical Lattice Clocks at the 101610^{-16} Uncertainty

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    Fiber-based remote comparison of 87^{87}Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches 5×10165\times10^{-16} over an averaging time of 1000 s, which is two orders of magnitude shorter than that of conventional satellite links and is limited by the instabilities of the optical clocks. By correcting the systematic shifts that are predominated by the differential gravitational redshift, the residual fractional difference is found to be (1.0±7.3)×1016(1.0\pm7.3)\times10^{-16}, confirming the coincidence between the two clocks. The accurate and speedy comparison of distant optical clocks paves the way for a future optical redefinition of the second