96 research outputs found

    Change in carbon nanofiber resistance from ambient to vacuum

    Get PDF
    The electrical properties of carbon nanofibers (CNFs) can be affected by adsorbed gas species. In this study, we compare the resistance values of CNF devices in a horizontal configuration in air and under vacuum. CNFs in air are observed to possess lower current capacities compared to those in vacuum. Further, Joule heating due to current stressing can result in desorption of gas molecules responsible for carrier trapping, leading to lower resistances and higher breakdown currents in vacuum, where most adsorbed gaseous species are evacuated before any significant re-adsorption can occur. A model is proposed to describe these observations, and is used to estimate the number of adsorbed molecules on a CNF device

    Sleep Quality is associated with Central Arterial Stiffness in Postmenopausal Women : A Cross-sectional Pilot Study

    Get PDF
    This study aimed to investigate the associations between sleep quality and arterial stiffness in healthy postmenopausal women. A total of 31 healthy postmenopausal women aged between 50 and 74 years participated in this study. Objectively and subjectively measured sleep quantity and quality were concomitantly obtained by a waist-worn actigraphy, Pittsburgh Sleep Quality Index (PSQI) questionnaire, and daily sleep diary. Carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), and femoral-ankle PWV (faPWV) were measured as indices of arterial stiffness. Based on the PSQI score, the participants were divided into good (PSQI 5.5; n = 10) sleepers. Self-reported sleep duration was significantly longer in poor sleepers than in good sleepers. However, there was no difference in total sleep time measured by actigraphy between the two groups. Additionally, sleep latency and wake after sleep onset significantly increased, and sleep efficiency significantly decreased in poor sleepers than in good sleepers. The cfPWV and baPWV were significantly higher in poor sleepers than in good sleepers, even after adjustment for risk factors (i.e., age, blood pressure, and physical activity), but no difference in faPWV. These results suggest that decreased sleep quality is associated with an increase in central arterial stiffness in postmenopausal women

    Attenuation of indirect markers of eccentric exercise-induced muscle damage by curcumin

    Get PDF
    Purpose: Polyphenolic curcumin is known to have potent anti-inflammatory effects; thus the present study investigated the hypothesis that curcumin ingestion would attenuate muscle damage after eccentric exercise. Methods: Fourteen untrained young men (24 ± 1 years) performed 50 maximal isokinetic (120°/s) eccentric contractions of the elbow flexors of one arm on an isokinetic dynamometer and the same exercise with the other arm 4 weeks later. They took 150 mg of curcumin (theracurmin) or placebo (starch) orally before and 12 h after each eccentric exercise bout in a randomised, crossover design. Maximal voluntary contraction (MVC) torque of the elbow flexors, range of motion of the elbow joint, upper-arm circumference, muscle soreness, serum creatine kinase (CK) activity, and plasma interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentration were measured before, immediately after, and 24, 48, 72 and 96 h after each eccentric exercise. Changes in these variables over time were compared between curcumin and placebo conditions by two-way repeated measures ANOVA. Results: MVC torque decreased smaller and recovered faster (e.g., 4 days post-exercise: −31 ± 13 % vs. −15 ± 15 %), and peak serum CK activity was smaller (peak: 7684 ± 8959 IU/L vs. 3398 ± 3562 IU/L) for curcumin than placebo condition (P \u3c 0.05). However, no significant differences between conditions were evident for other variables, and no significant changes in IL-6 and TNF-α were evident after exercise. Conclusion: It is concluded that theracurmin ingestion attenuates some aspects of muscle damage such as MVC loss and CK activity increase

    Aerobic exercise training enhances cerebrovascular pulsatility response to acute aerobic exercise in older adults

    Get PDF
    The brain\u27s low resistance ensures a robust blood flow throughout systole and diastole and is susceptible to flow pulsatility. Increased cerebral pulsatility contributes to the progression of cerebrovascular disease. Although aerobic exercise affects vascular function, little is known about the effect of exercise on the cerebral pulsatility index in older adults. The aim of this study was to investigate the effect of exercise training on the post‐exercise cerebral pulsatility response in older adults. Ten healthy older adults participated in a 12‐week exercise training intervention. Before and after the intervention, we measured the pulsatility index of the middle cerebral artery by means of transcranial Doppler method at baseline and following a cycling exercise bout performed at an intensity corresponding to the ventilatory threshold. Before exercise training, there was no significant change in the cerebral pulsatility response to an acute bout of cycling exercise. However, after the intervention, cerebral pulsatility decreased significantly following 30 min of an acute cycling exercise (P < 0.05). This study demonstrated that cerebral pulsatility index did not change following an acute bout of cycling exercise at an intensity corresponding to ventilatory threshold, but that, after 12 weeks of exercise training, cerebral pulsatility index was reduced at 30 min after a single bout of cycling exercise. These results suggest that long‐term aerobic exercise training may enhance the post‐exercise reduction in pulsatility index in older adults

    Habitual aerobic exercise increases plasma pentraxin 3 levels in middle-aged and elderly women

    Get PDF
    Chronic inflammation that occurs with aging is one of the risk factors for cardiovascular disease. Regular exercise may prevent cardiovascular morbidity by decreasing chronic systematic inflammation. Additionally, excess inflammation can be reduced by the anti-inflammatory protein pentraxin 3 (PTX3). Thus, both habitual exercise and PTX3 have an anti-inflammatory effect. However, it is unclear whether regular exercise leads to increased plasma PTX3 concentration. In the present study, we investigated the effects of regular aerobic exercise on plasma PTX3 concentration in middle-aged and elderly women. Twenty-two postmenopausal women (60 ± 6 years) were randomly divided evenly into 2 groups (i.e., exercise intervention and control). Subjects in the exercise group completed 2 months of regular aerobic exercise training (walking and cycling, 30-45 min, 3-5 days·week(-1)). Before and after the intervention, we evaluated plasma PTX3 concentration, peak oxygen uptake, blood chemistry, and arterial distensibility (carotid arterial compliance and β-stiffness) in all participants. There were no significant differences in baseline parameters between the 2 groups. Plasma PTX3 concentration was significantly increased in the exercise group after the intervention (p < 0.05). High-density lipoprotein cholesterol, peak oxygen uptake, and arterial compliance were also significantly increased (p < 0.05), while β-stiffness was markedly decreased (p < 0.01) after the intervention. On the other hand, there was no change in the parameters tested in the control group. This study demonstrates that regular aerobic exercise increases plasma PTX3 concentration with improvement of high-density lipoprotein cholesterol, peak oxygen uptake, and arterial distensibility in postmenopausal women

    Comparative proteomic analysis of Salmonella enterica serovar Typhimurium ppGpp-deficient mutant to identify a novel virulence protein required for intracellular survival in macrophages

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The global ppGpp-mediated stringent response in pathogenic bacteria plays an important role in the pathogenesis of bacterial infections. In <it>Salmonella enterica </it>serovar Typhimurium (<it>S</it>. Typhimurium), several genes, including virulence genes, are regulated by ppGpp when bacteria are under the stringent response. To understand the control of virulence genes by ppGpp in <it>S</it>. Typhimurium, agarose 2-dimensional electrophoresis (2-DE) combined with mass spectrometry was used and a comprehensive 2-DE reference map of amino acid-starved <it>S</it>. Typhimurium strain SH100, a derivative of ATCC 14028, was established.</p> <p>Results</p> <p>Of the 366 examined spots, 269 proteins were successfully identified. The comparative analysis of the wild-type and ppGpp<sup>0 </sup>mutant strains revealed 55 proteins, the expression patterns of which were affected by ppGpp. Using a mouse infection model, we further identified a novel virulence-associated factor, STM3169, from the ppGpp-regulated and <it>Salmonella</it>-specific proteins. In addition, <it>Salmonella </it>strains carrying mutations in the gene encoding STM3169 showed growth defects and impaired growth within macrophage-like RAW264.7 cells. Furthermore, we found that expression of <it>stm3169 </it>was controlled by ppGpp and SsrB, a response regulator of the two-component system located on <it>Salmonella </it>pathogenicity island 2.</p> <p>Conclusions</p> <p>A proteomic approach using a 2-DE reference map can prove a powerful tool for analyzing virulence factors and the regulatory network involved in <it>Salmonella </it>pathogenesis. Our results also provide evidence of a global response mediated by ppGpp in <it>S. enterica</it>.</p

    Sexual Function Is an Indicator of Central Arterial Stiffness and Arterial Stiffness Gradient in Japanese Adult Men

    Get PDF
    BackgroundAs arterial stiffness increases in the absence of subjective symptoms, a personal indicator that reflects increased risk of cardiovascular disease is necessary. Penile erection is regulated by vascular function, and atherosclerosis affects the penile artery earlier than it affects the coronary and carotid arteries. Therefore, we hypothesized that deterioration of erectile function could be a marker of increased risk for cardiovascular disease. To test our hypothesis, we assessed erectile function and arterial stiffness in a cross‐sectional study.Methods and ResultsCarotid‐femoral pulse wave velocity (PWV), brachial‐ankle PWV, femoral‐ankle PWV, and arterial stiffness gradient (PWV ratio: carotid‐femoral PWV/femoral‐ankle PWV) were measured as indexes of central, systemic, and peripheral arterial stiffness and peripheral organ damage, respectively, in 317 adult men. In addition, erectile function was assessed by using the questionnaire International Index of Erectile Function 5 (a descending score indicates worsening of erectile function). The scores of male sexual function were inversely correlated with carotid‐femoral PWV (rs=−0.41), brachial‐ankle PWV (rs=−0.35), femoral‐ankle PWV (rs=−0.19), and PWV ratio (rs=−0.33). Furthermore, multivariate linear regression analyses revealed that International Index of Erectile Function 5 scores were significantly associated with carotid‐femoral PWV (β=−0.22) and PWV ratio (β=−0.25), but not with brachial‐ankle PWV and femoral‐ankle PWV.ConclusionsOur results indicated that erectile function is independently associated with central arterial stiffness and peripheral organ damage. These findings suggest that male sexual function could be an easily identifiable and independent marker of increased central arterial stiffness and peripheral organ damage

    Hyperadiponectinemia enhances bone formation in mice

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>There is growing evidence that adiponectin, a physiologically active polypeptide secreted by adipocytes, controls not only adipose tissue but also bone metabolism. However, a role for adiponectin in bone development remains controversial.</p> <p>Methods</p> <p>We therefore investigated the endocrine effects of adiponectin on bone metabolism using 12-week-old male transgenic (Ad-Tg) mice with significant hyperadiponectinemia overexpressing human full-length adiponectin in the liver.</p> <p>Results</p> <p>In Ad-Tg mice, the serum level of osteocalcin was significantly increased, but the levels of RANKL, osteoprotegerin, and TRAP5b were not. Bone mass was significantly greater in Ad-Tg mice with increased bone formation. In contrast, bone resorption parameters including the number of osteoclasts and eroded surface area did not differ between Ad-Tg and their littermates.</p> <p>Conclusions</p> <p>These findings demonstrate that hyperadiponectinemia enhances bone formation in mice.</p
    corecore