123 research outputs found

    Naringenin suppresses neutrophil infiltration into adipose tissue in high-fat diet-induced obese mice

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    Recruitment of immune cells to adipose tissue is altered dramatically in obesity, which results in chronic inflammation ofthe adipose tissue that leads to metabolic disorders, such as insulin resistance and type 2 diabetes mellitus. The regulationof immune cell infiltration into adipose tissue has prophylactic and therapeutic implications for obesity-related diseases. Wepreviously showed that naringenin, a citrus flavonoid, suppressed macrophage infiltration into adipose tissue by inhibitingmonocyte chemoattractant protein-1 (MCP-1) expression in the progression phase to high-fat diet (HFD)-induced obesity.In the current study, we evaluated the effects of naringenin on neutrophil infiltration into adipose tissue, because neutrophilsalso infiltrate into adipose tissue in the progression phase to obesity. Naringenin suppressed neutrophil infiltration into adiposetissue induced by the short-term (2 weeks) feeding of a HFD to mice. Naringenin tended to inhibit the HFD-inducedexpression of several chemokines, including MCP-1 and MCP-3, in adipose tissue. Naringenin also inhibited MCP-3 expressionin 3T3-L1 adipocytes and a co-culture of 3T3-L1 adipocytes and RAW264 macrophages. However, naringenin did notaffect the expression of macrophage inflammatory protein-2 (MIP-2), an important chemokine for neutrophil migration andactivation, in macrophages or in a co-culture of adipocytes and macrophages. Our results suggest that naringenin suppressesneutrophil infiltration into adipose tissue via the regulation of MCP-3 expression and macrophage infiltration.九州保健福祉大学201

    Emergence of a Twisted Magnetic Flux Bundle as a Source of Strong Flare Activity

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    Sunspot proper motions and flares of a super active region NOAA 5395, which was the biggest and the most flare-active region in the 22nd sunspot cycle, were analyzed in details. We measured sunspot proper motions by using the H-alpha - 5.0 A images obtained with the 60-cm Domeless Solar Telescope (DST) at Hida Observatory, Kyoto University and found some peculiar vortex-like motions of small satellite spots successively emerged from the leading edge of this sunspot group. To explain these motions of small sunspots, we proposed a schematic model of the successive emergence of twisted and winding magnetic flux ropes coiling around a trunk of magnetic flux tube. The location of the strongest flare activity was found to coincide with very the site of the vortex-like motions of sunspots. We conclude that the flare-productive magnetic shear is produced by the emergence of the twisted magnetic flux bundle. Magnetic energy is stored in the twisted flux tubes which are originally formed in the convection zone and released as flares in the course of the emergence of the twisted flux tubes above the photosphere.Comment: 19 pages LaTeX, 8 figures, ApJ accepted high resolution figures : e-mail to [email protected]

    Action of an endo-β-1,3(4)-glucanase on cellobiosyl unit structure in barley β-1,3:1,4-glucan.

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    β-1,3:1,4-Glucan is a major cell wall component accumulating in endosperm and young tissues in grasses. The mixed linkage glucan is a linear polysaccharide mainly consisting of cellotriosyl and cellotetraosyl units linked through single β-1,3-glucosidic linkages, but it also contains minor structures such as cellobiosyl units. In this study, we examined the action of an endo-β-1,3(4)-glucanase from Trichoderma sp. on a minor structure in barley β-1,3:1,4-glucan. To find the minor structure on which the endo-β-1,3(4)-glucanase acts, we prepared oligosaccharides from barley β-1,3:1,4-glucan by endo-β-1,4-glucanase digestion followed by purification by gel permeation and paper chromatography. The endo-β-1,3(4)-glucanase appeared to hydrolyze an oligosaccharide with degree of polymerization 5, designated C5-b. Based on matrix-assisted laser desorption/ionization (MALDI) time-of-flight (ToF)/ToF-mass spectrometry (MS)/MS analysis, C5-b was identified as β-Glc-1,3-β-Glc-1,4-β-Glc-1,3-β-Glc-1,4-Glc including a cellobiosyl unit. The results indicate that a type of endo-β-1,3(4)-glucanase acts on the cellobiosyl units of barley β-1,3:1,4-glucan in an endo-manner.This work was supported in part by a grant-in-aid for Scientific Research to T. Kotake [Grant-in-Aid for Scientific Research no. 25514001] from Japan Society of the Promotion of Science; Y. Tsumuraya and T. Kotake [Grant-in-Aid for Scientific Research no. 24114006] from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. Supports were also provided by BBSRC Sustainable Bioenergy Centre: Cell wall sugars program to P. Dupree [grant number BB/G016240/1].This is the final version of the article. It first appeared from Taylor & Francis via http://dx.doi.org/10.1080/09168451.2015.104636

    The X10 Flare on 2003 October 29: Triggered by Magnetic Reconnection between Counter-Helical Fluxes?

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    Vector magnetograms taken at Huairou Solar Observing Station (HSOS) and Mees Solar Observatory (MSO) reveal that the super active region (AR) NOAA 10486 was a complex region containing current helicity flux of opposite signs. The main positive sunspots were dominated by negative helicity fields, while positive helicity patches persisted both inside and around the main positive sunspots. Based on a comparison of two days of deduced current helicity density, pronounced changes were noticed which were associated with the occurrence of an X10 flare that peaked at 20:49 UT, 2003 October 29. The average current helicity density (negative) of the main sunspots decreased significantly by about 50. Accordingly, the helicity densities of counter-helical patches (positive) were also found to decay by the same proportion or more. In addition, two hard X-ray (HXR) `footpoints' were observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI} during the flare in the 50-100 keV energy range. The cores of these two HXR footpoints were adjacent to the positions of two patches with positive current helicity which disappeared after the flare. This strongly suggested that the X10 flare on 2003 Oct. 29 resulted from reconnection between magnetic flux tubes having opposite current helicity. Finally, the global decrease of current helicity in AR 10486 by ~50% can be understood as the helicity launched away by the halo coronal mass ejection (CME) associated with the X10 flare.Comment: Solar Physics, 2007, in pres

    Distribution of Japanese Eel Anguilla japonica Revealed by Environmental DNA

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    絶滅危惧種ニホンウナギの分布域を環境DNA解析で推定. 京都大学プレスリリース. 2021-03-03.The abundance of Japanese eel Anguilla japonica has rapidly decreased in recent decades. Following a re-evaluation of the possibility of extinction, the Japanese Ministry of the Environment and the International Union for Conservation of Nature listed the Japanese eel as an endangered species in 2013 and 2014, respectively. However, their abundance and precise distribution have never been clarified owing to their nocturnality and difficulty in their capture. In this study, the distribution of Japanese eels was investigated by monitoring for environmental DNA (eDNA), a non-invasive and efficient detection method. A total of 365 water samples were collected from 265 rivers located throughout Japan. High concentrations of eDNA of Japanese eels were detected in rivers on the Pacific side, but were low in the Sea of Japan side. In particular, very little eDNA amplification was confirmed from Hokkaido and the north of the Sea of Japan. The eDNA distribution in Japanese rivers coincides with the transport of the larvae in the ocean, as estimated by numerical simulations. Generalized linear mixed models were developed to explain the distribution of eDNA concentrations. The total nitrogen concentration emerged as an important factor in the best model. These results indicate that the distribution of Japanese eel is mostly determined by the maritime larval transport, and their survival and growth depend on the abundance of food in the river. The findings of the present study are useful for the management of populations and in the conservation of Japanese eels
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