97 research outputs found

    Cardiomyocyte culture with in vivo functions

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    Rationale Diabetes causes cardiac dysfunction, and understanding of its mechanism is still incomplete. One reason could be limitations in modeling disease conditions by current in vitro cardiomyocyte culture. Emerging evidence suggests that the mechanical properties of the microenvironment affect cardiomyocyte function. Nevertheless, the impact of high glucose on cardiomyocytes cultured on substrates whose stiffness matches that of the heart (approximately 15 kPa) is untested. Objective To test the hypothesis that cardiomyocytes cultured in microenvironments that mimic the mechanical properties of those for cardiomyocytes in vivo may reproduce the pathophysiology characteristics of diabetic cardiomyocytes ex vivo, such as the morphological appearance, ROS accumulation, mitochondrial dysfunction, apoptosis and insulin-stimulated glucose uptake. Methods and results Isolated neonatal rat cardiomyocytes were seeded on 15 kPa polyacrylamide (PAA) gels, whose stiffness mimics that of heart tissues, or on glass coverslips, which represent conventional culture devices but are unphysiologically stiff. Cells were then cultured at 5 mM glucose, corresponding to the normal blood glucose level, or at high glucose levels (10 to 25 mM). Cytoskeletal disorganization, ROS accumulation, attenuated mitochondrial membrane potential and attenuated ATP level caused by high glucose and their reversal by a ROS scavenger were prominent in cells on gels, but not in cells on coverslips. The lack of response to ROS scavenging could be attributable to enhanced apoptosis in cells on glass, shown by enhanced DNA fragmentation and higher caspase 3/7 activity in cells on glass coverslips. High-glucose treatment also downregulated GLUT4 expression and attenuated insulin-stimulated glucose uptake only in cells on 15 kPa gels. Conclusion Our data suggest that a mechanically compliant microenvironment increases the susceptibility of primary cardiomyocytes to elevated glucose levels, which enables these cells to serve as an innovative model for diabetic heart research

    Fatty-acid metabolism is involved in stress-resistance mechanisms of Caenorhabditis elegans

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    Fatty acids are the major components of the phospholipid bilayer and are involved in several functions of cell membrane. We previously reported that fatty-acid metabolism is involved in the regulation of DAF-2/insulin signal in Caenorhabditis elegans. In this study, we investigate the role of fatty-acid metabolism in stress resistance with respect to daf-16 in nematode. We found that fatty-acid metabolism regulates heat, osmotic, and oxidative-stress resistance in C. elegans. RNA interference (RNAi) of fat-6, fat-7, and elo-2 enhanced heat resistance but decreased oxidative-stress tolerance. RNAi of fat-2 strongly increased osmotic-stress resistance, whereas nhr-49-RNAi remarkably reduced osmotic and oxidative-stress tolerance. In daf-16 mutants (mgDf50), RNAi of fat-2 and fat-7 increased viability under osmotic stress, while RNAi of fat-6, fat-7, and elo-2 enhanced heat resistance. Exposure of saturated fatty acids to RNAi worms of fat-1-, fat-7-, and nhr-49 increased osmotic resistance. On the other hand, polyunsaturated fatty acids (PUFAs) reduced osmotic-stress tolerance in fat-2-RNAi worms, whereas PUFAs enhanced it in nhr-49-RNAi worms. Heat-stress resistance in fat-6- and fat-7-RNAi worms was suppressed by oleic acid.These results suggest that stress-resistance mechanisms are regulated by fatty-acid metabolism with or without DAF-16 activity

    Advancements in the Epsilon Launch Vehicle\u27s Rideshare Capability and Future Missions

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    Fifth Epsilon launch vehicle (Epsilon-5) with Innovative Satellite Technology Demonstration-2 was successfully launched from JAXA Uchinoura Space Center in Kagoshima, Japan on November 9, 2021. Successful injection of nine satellites with high accuracy demonstrated the capability of Epsilon launch vehicle for rideshare missions of various satellite sizes. The new Epsilon Satellite Mount Structure-II (ESMS-II) and an adapter was developed to launch more satellites. In the paper, we first introduce Epsilon launch vehicle and its multi-launch capability. Then, we describe the mission design of Epsilon-5 and rideshare specific configuration. Finally, we mention the rideshare opportunity provided by Epsilon launch vehicle in the future

    絵本における「比喩的表現」 : 「大きさ」の比喩的表現を子どもはどうとらえているか

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    絵本には,比喩的な語彙の使用が多い。それは文学的な表現であるだけでなく,対象者である幼児の内容理解を促進するために用いる場合もある。その際,対象者であるこどもの認識,知識,語彙にあわせた表現の配慮がなされる。絵本を作る側にいる者として,その比喩をどのような理解しているのかを,「ちいさなもの」「おおきなもの」を表現した絵本テキストを読み聞かせ,その大きさを幼児に行動で示させることで,比喩的表現の理解程度を検証した。Figurative speech is often used in children\u27s picture books. This is not merely a literary device but can also serve to facilitate understanding of the content for the intended audience of children readers. In suchcases, the child readers\u27 knowledge, experience and vocabulary must be carefully considered when selectingappropriate language. From the perspective of a creator of children\u27s picture books, a study was conducted to determine the ways in which children understand such figurative speech by reading them a text containingthe expressions "small things" and "large things", then having them act out their perceptions of size withtheir bodie

    The royal food of termites shows king and queen specificity

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    シロアリの王と女王の特別食を世界初解明 --王と女王の繁殖と長寿を支えるロイヤルフード--. 京都大学プレスリリース. 2023-07-13.Society in eusocial insects is based on the reproductive division of labor, with a small number of reproductive individuals supported by a large number of non-reproductive individuals. Because inclusive fitness of all colony members depends on the survival and fertility of reproductive members, sterile members provide royals with special treatment. Here we show that termite kings and queens each receive special food of a different composition from workers. Sequential analysis of feeding processes demonstrated that workers exhibit discriminative trophallaxis, indicating their decision-making capacity in allocating food to the kings and queens. LC-MS/MS analyses of the stomodeal food and midgut contents revealed king- and queen-specific compounds including diacylglycerols and short-chain peptides. DESI-MSI analyses of ¹³C-labelled termites identified phosphatidylinositol and acetyl-L-carnitine in the royal food. Comparison of the digestive tract structure showed remarkable differences in the volume ratio of the midgut-to-hindgut among castes, indicating that digestive division of labor underlies reproductive division of labor. Our demonstration of king- and queen-specific food in termites provides insight into the nutritional system that underpins the extraordinary reproduction and longevity of royals in eusocial insects

    Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

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    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16×12∘ and a spatial resolution of 0.05∘ per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission

    Molecular Evolutionary Analysis of the Influenza A(H1N1)pdm, May–September, 2009: Temporal and Spatial Spreading Profile of the Viruses in Japan

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    BACKGROUND: In March 2009, pandemic influenza A(H1N1) (A(H1N1)pdm) emerged in Mexico and the United States. In Japan, since the first outbreak of A(H1N1)pdm in Osaka and Hyogo Prefectures occurred in the middle of May 2009, the virus had spread over 16 of 47 prefectures as of June 4, 2009. METHODS/PRINCIPAL FINDINGS: We analyzed all-segment concatenated genome sequences of 75 isolates of A(H1N1)pdm viruses in Japan, and compared them with 163 full-genome sequences in the world. Two analyzing methods, distance-based and Bayesian coalescent MCMC inferences were adopted to elucidate an evolutionary relationship of the viruses in the world and Japan. Regardless of the method, the viruses in the world were classified into four distinct clusters with a few exceptions. Cluster 1 was originated earlier than cluster 2, while cluster 2 was more widely spread around the world. The other two clusters (clusters 1.2 and 1.3) were suggested to be distinct reassortants with different types of segment assortments. The viruses in Japan seemed to be a multiple origin, which were derived from approximately 28 transported cases. Twelve cases were associated with monophyletic groups consisting of Japanese viruses, which were referred to as micro-clade. While most of the micro-clades belonged to the cluster 2, the clade of the first cases of infection in Japan originated from cluster 1.2. Micro-clades of Osaka/Kobe and the Fukuoka cases, both of which were school-wide outbreaks, were eradicated. Time of most recent common ancestor (tMRCA) for each micro-clade demonstrated that some distinct viruses were transmitted in Japan between late May and early June, 2009, and appeared to spread nation-wide throughout summer. CONCLUSIONS: Our results suggest that many viruses were transmitted from abroad in late May 2009 irrespective of preventive actions against the pandemic influenza, and that the influenza A(H1N1)pdm had become a pandemic stage in June 2009 in Japan
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