547 research outputs found

    The Ds(2317) and Ds(2463) Mesons as Scalar and Axial-Vector Chiralons in the Covariant Level-Classification Scheme

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    The new narrow mesons observed recently in the final states Ds+ pi0 and Ds*+ pi0 are pointed out to be naturally assigned as the ground-state scalar and axial-vector chiralons in the c sbar system, which would newly appear in the covariant hadron-classification scheme proposed a few years ago.Comment: 8 pages, 1 figure, uses ptptex.st

    Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide

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    The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule

    Heme oxygenase-1 induction in the brain during lipopolysaccharide-induced acute inflammation

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    Delirium occurs in 23% of sepsis patients, in which pro-inflammatory cytokines and nitric oxide are suggested to be involved. However, in animal experiments, even a subseptic dose of lipopolysaccharide (LPS) injection induces both pro-inflammatory cytokines and inducible nitric oxide synthase in the brain, suggesting that the brain oxidative reaction can be induced in the subseptic condition. Then, we evaluated the changes of heme oxygenase-1 (HO-1), a sensitive oxidative marker, as well as interleukin (IL)-1β, IL-6, and inductible nitric oxide synthase (iNOS) mRNA in the hypothalamus and hippocampus of rats using real-time PCR after peripheral injection of LPS (2.0 mg/kg). As a result, these four kinds of mRNAs were induced significantly in both areas after LPS injection. These results suggest that peripheral inflammation induces an oxidative reaction in the brain, even if the inflammation is not lethal. It is also considered that several pathways are involved in brain HO-1 induction

    TAT-dextran-mediated mitochondrial transfer enhances recovery from models of reperfusion injury in cultured cardiomyocytes

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    Acute myocardial infarction is a leading cause of death among single organ diseases. Despite successful reperfusion therapy, ischaemia reperfusion injury (IRI) can induce oxidative stress (OS), cardiomyocyte apoptosis, autophagy and release of inflammatory cytokines, resulting in increased infarct size. In IRI, mitochondrial dysfunction is a key factor, which involves the production of reactive oxygen species, activation of inflammatory signalling cascades or innate immune responses, and apoptosis. Therefore, intercellular mitochondrial transfer could be considered as a promising treatment strategy for ischaemic heart disease. However, low transfer efficiency is a challenge in clinical settings. We previously reported uptake of isolated exogenous mitochondria into cultured cells through co-incubation, mediated by macropinocytosis. Here, we report the use of transactivator of transcription dextran complexes (TAT-dextran) to enhance cellular uptake of exogenous mitochondria and improve the protective effect of mitochondrial replenishment in neonatal rat cardiomyocytes (NRCMs) against OS. TAT-dextran-modified mitochondria (TAT-Mito) showed a significantly higher level of cellular uptake. Mitochondrial transfer into NRCMs resulted in anti-apoptotic capability and prevented the suppression of oxidative phosphorylation in mitochondria after OS. Furthermore, TAT-Mito significantly reduced the apoptotic rates of cardiomyocytes after OS, compared to simple mitochondrial transfer. These results indicate the potential of mitochondrial replenishment therapy in OS-induced myocardial IRI
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