106 research outputs found

    Progress of silicon carbide fibers and their application to ceramic matrix composites

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    Silicon carbide fibers have high strength and high modulus and they are provided with flexible, multi-filament yarn. Durability test was demonstrated to provide superior property among kinds of ceramic fibers under heat and stress in oxidative environment (Figure 1). It was in 1975 that SiC fiber was invented by converting organosilicon polymer into ceramics by pyrolysis. Thereafter Nippon Carbon industrialized SiC fiber, NicalonTM, in 1983. Developing the next-generation SiC fibers has been continued. At first, the improved heat-resistant SiC fiber by reduced oxygen content has been developed. Next, the fiber with higher modulus and improved creep resistance has been developed by means of near-stoichiometric SiC composition and higher crystallinity, named Hi-Nicalon Type S. Please click Additional Files below to see the full abstract

    International reliability assessment project through standard PateranoSiC(SiC/SiC)

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    Oxidants induce transcriptional activation of manganese superoxide dismutase in glomerular cells

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    Oxidants induce transcriptional activation of manganese superoxide dismutase in glomerular cells. Cultured rat glomerular mesangial and epithelial cells and bovine glomerular endothelial cells were exposed to various concentrations of hydrogen peroxide (H2O2). Mesangial cells treated with 10 to 100 µM H2O2 for 24 hours showed a two- to ninefold increase in Mn-SOD mRNA expression associated with significantly (P < 0.005) increased Mn-SOD activity (22.2 ± 1.2 and 12.2 ± 0.7 µ/mg protein for H2O2 100 µM treated and untreated cells, respectively). In contrast, expression of Cu-Zn SOD and β-actin mRNA was not affected by H2O2. Induction of Mn-SOD mRNA by H2O2 was inhibited by actinomycin-D (4 µM) treatment. Glomerular endothelial cells also showed an increase in Mn-SOD mRNA expression following 100 µM H2O2 treatment, as did glomerular epithelial cells following treatment with 500 and 1000 µM H2O2 but not with 100 µM. Transcriptional activity of the Mn-SOD gene was assessed with a fusion reporter gene consisting of a luciferase gene (pGL2P) and a 1.2 kb fragment from the rat Mn-SOD genomic DNA (-806 to +408 bp of the transcription initiation site, -806:+408). The construct was transfected into rat glomerular mesangial and epithelial cells. Mesangial and epithelial cells transfected with pGL2P (-806:+408) and treated with H2O2 (100 µM and 1 mM for mesangial and epithelial cells, respectively) demonstrated some threefold increase in luciferase activity, whereas cells transfected with pGL2P lacking the Mn-SOD fragment did not show changes in luciferase activity following H2O2 treatment. Other oxidants, namely α- and β-naphthoflavone (50 µM to mesangial cells) and puromycin aminonucleoside (25 to 50 µg/ml to epithelial cells), also induced transcriptional activation (2- to 5-fold increase) in these cells. Thus, Mn-SOD levels in glomerular cells are enhanced when they are exposed to oxidant stress, and this up-regulation involves transcriptional activation. Further, the Mn-SOD gene contains enhancer element(s) which respond to diverse oxidant stress. The inducibility by oxidants of local Mn-SOD demonstrates that glomerular SOD may play a decisive role in the pathogenesis of glomerular injuries in which the balance between oxidants and antioxidants is critical

    Interleukin-10 in the Pathophysiology of Inflammatory Bowel Disease: Increased Serum Concentrations During the Recovery Phase

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    Using a specific enzyme-linked immunosorbent assay, IL-10 concentrations were measured in serum from 62 patients with ulcerative colitis (UC), 43 with Crohn's disease (CD), 25 with other colitides, and 44 normal control subjects. Serum IL-10 concentrations were increased in patients with active UC but not in those with active CD when compared with normal control subjects. A time course study showed that in patients with UC and CD, serum concentrations of IL-6 and C-reactive protein increased during the acute phase and returned to normal as patients go into remission. Notably, serum IL-10 concentrations increased during the phase of disease resolution and declined thereafter regardless of the treatment modality. Gel filtration analysis indicated that IL-10 circulated predominantly as a dimer. In conclusion, this study shows that serum IL-10 is increased during disease recovery in patients with inflammatory bowel disease, and may be a helpful marker in monitoring disease status

    Decreased ADP-Ribosyl Cyclase Activity in Peripheral Blood Mononuclear Cells from Diabetic Patients with Nephropathy

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    Aims/hypothesis. ADP-ribosyl-cyclase activity (ADPRCA) of CD38 and other ectoenzymes mainly generate cyclic adenosine 5’diphosphate-(ADP-) ribose (cADPR) as a second messenger in various mammalian cells, including pancreatic beta cells and peripheral blood mononuclear cells (PBMCs). Since PBMCs contribute to the pathogenesis of diabetic nephropathy, ADPRCA of PBMCs could serve as a clinical prognostic marker for diabetic nephropathy. This study aimed to investigate the connection between ADPRCA in PBMCs and diabetic complications. Methods. PBMCs from 60 diabetic patients (10 for type 1 and 50 for type 2) and 15 nondiabetic controls were fluorometrically measured for ADPRCA based on the conversion of nicotinamide guanine dinucleotide (NGD+) into cyclic GDP-ribose. Results. ADPRCA negatively correlated with the level of HbA1c (P = .040, R2 = .073), although ADPRCA showed no significant correlation with gender, age, BMI, blood pressure, level of fasting plasma glucose and lipid levels, as well as type, duration, or medication of diabetes. Interestingly, patients with nephropathy, but not other complications, presented significantly lower ADPRCA than those without nephropathy (P = .0198) and diabetes (P = .0332). ANCOVA analysis adjusted for HbA1c showed no significant correlation between ADPRCA and nephropathy. However, logistic regression analyses revealed that determinants for nephropathy were systolic blood pressure and ADPRCA, not HbA1c. Conclusion/interpretation. Decreased ADPRCA significantly correlated with diabetic nephropathy. ADPRCA in PBMCs would be an important marker associated with diabetic nephropathy

    Effect of Radiological Countermeasures on Subjective Well-Being and Radiation Anxiety after the 2011 Disaster: The Fukushima Health Management Survey

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    After the Fukushima Daiichi Nuclear Power Station accident in 2011, concerns about radiation exposure and decline in subjective well-being have been reported. To tackle these problems, various countermeasures in relation to radiation have been implemented. In this study, we comprehensively evaluated the effects of radiological countermeasures on subjective well-being (e.g., satisfaction with life (SWL) and emotional well-being) and radiation anxiety, through a questionnaire survey targeting Fukushima residents (N = 1023). Propensity scores matching was applied to evaluate significant effects of radiological countermeasures on subjective well-being and radiation anxiety. Among the radiological countermeasures, thyroid examination, whole body counter, and air dose monitoring showed the highest proportions of participation, utilization, and useful evaluation, suggesting a high degree of public attention focused on these countermeasures. The basic survey was associated with significant increases in SWL and self-rated health (SH). Thyroid examination was significantly associated with not only a reduction in radiation anxiety but also an increase of emotional stress, suggesting the importance of careful design of system and detailed communication. Food inspection was associated with deterioration in SH. Those who utilized explanatory meetings showed increases in sadness, worry, and radiation anxiety, indicating that additional attention is required of the experts and authorities involved in explanatory meetings

    Diabetes mellitus itself increases cardio- cerebrovascular risk and renal complications in primary aldosteronism

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    This is a pre-copyedited, author-produced version of an article accepted for publication in The Journal of Clinical Endocrinology & Metabolism following peer review. The version of record Aya Saiki, Michio Otsuki, Daisuke Tamada, Tetsuhiro Kitamura, Iichiro Shimomura, Isao Kurihara, Takamasa Ichijo, Yoshiyu Takeda, Takuyuki Katabami, Mika Tsuiki, Norio Wada, Toshihiko Yanase, Yoshihiro Ogawa, Junji Kawashima, Masakatsu Sone, Nobuya Inagaki, Takanobu Yoshimoto, Ryuji Okamoto, Katsutoshi Takahashi, Hiroki Kobayashi, Kouichi Tamura, Kohei Kamemura, Koichi Yamamoto, Shoichiro Izawa, Miki Kakutani, Masanobu Yamada, Akiyo Tanabe, Mitsuhide Naruse, Diabetes Mellitus Itself Increases Cardio-Cerebrovascular Risk and Renal Complications in Primary Aldosteronism, The Journal of Clinical Endocrinology & Metabolism, Volume 105, Issue 7, July 2020, Pages e2531–e2537 is available online at: https://doi.org/10.1210/clinem/dgaa177
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