1,020 research outputs found

    Effects of muscular response for the intensity of vibratory stimulus applied on the ankle tendon

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    The present study was conducted to measure the individual threshold value for the somatosensory system of the human body, the thresholds value of vibratory stimulus were assessed through the ascent and descent methods. In the interests of the attainment of this study`s goal, comparing the thresholds value measured and change of state of the muscles when applied on the ankle tendon connected to muscles, changes in threshold measurement accuracy due to the differences in measuring methods were discussed. The experiment was conducted by constructing systems to stimulate somethetic sensibility by vibratory stimulus, ultrasound imaging system and EMG system. Five adult males were involved in this experiment. According to the results of experiments, the threshold value of somatosensory stimulation measured by the ascent method was greater than the threshold values measured by the descent method. And the muscular response to the somatosensory stimulation applied to the tibialis anterior tendon showed a larger rate of change with the ascending stimulus than with the descending stimulus. The results of this study could serve as a basis to discuss the reliability of the measurement method of the human body’s individual threshold value for the somatosensory system through the ascent and descent methods and can be used as reference data for the integration and performance threshold measurement methods

    A study on the changes in gait characteristics by applying sub-threshold vibration stimulus in the ankle

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    This study was conducted to suggest the potential use of a mechanical vibration stimulus in the ankle to correct gait abnormalities. As for the mechanical vibration stimulus, different locations and durations are suggested based on the detection results of real-time gait patterns. 5 young males participated in this study. They were asked to perform assigned gait tasks when either a threshold or sub-threshold stimulus was applied in the tibialis anterior and Achilles tendon. The analysis results of gait cycle and muscle activity showed the changes on gait cycle, the activity pattern of used muscle for gait and the movement pattern of the ankle were observed based on the applied locations of vibration stimulus. Also, the result of sub-threshold stimulus showed similar effects as that of threshold stimulus. As such, the mechanical vibration stimulus was considered to affect gait by being adjusted its characteristics and local stimulus also would affect human body systemically. The result of this study can be used as basic data for the correction of individual’s specific gait abnormality and rehabilitation using vibration stimulus

    La cuestión de la verdad histórica en Abril rojo, de Santiago Roncagliolo

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    Control of nacre biomineralization by Pif80 in pearl oyster

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    Molluscan nacre is a fascinating biomineral consisting of a highly organized calcium carbonate composite that provides unique fracture toughness and an iridescent color. Organisms elaborately control biomineralization using organic macromolecules. We propose the involvement of the matrix protein Pif80 from the pearl oyster Pinctada fucata in the development of the inorganic phase during nacre biomineralization, based on experiments using the recombinant form of Pif80. Through interactions with calcium ions, Pif80 participates in the formation of polymer-induced liquid precursor-like amorphous calcium carbonate granules and stabilizes these granules by forming calcium ion-induced coacervates. At the calcification site, the disruption of Pif80 coacervates destabilizes the amorphous mineral precursors, resulting in the growth of a crystalline structure. The redissolved Pif80 controls the growth of aragonite on the polysaccharide substrate, which contributes to the formation of polygonal tablet structure of nacre. Our findings provide insight into the use of organic macromolecules by living organisms in biomineralization.117Ysciescopu

    Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.

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    Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH

    Anti-amyloidogenic effect of menaquinone-7 on betaamyloid production and aggregation

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    Purpose: To investigate the beneficial effects of menaquinone-7 (MK-7), an isoform of vitamin K2, against beta-amyloid (Aβ) production and aggregation in Alzheimer's disease using in vitro assays. Methods: The cytotoxicity of MK-7 was determined by MTT assay. The amount of Aβ produced and secreted into the supernatant by APP-CHO cells treated with MK-7 was evaluated by ELISA. The expression of β-secretases and ADAM10, a representative α-secretase, was determined using western blot analysis. The production of sAPPβ and sAPPα fragments generated by β-secretases and αsecretase, respectively, were also determined by western blot analysis. The effect on Aβ aggregation was assessed using Thioflavin T (Th T) assay. Results: MK-7 (up to 75 nM) significantly decreased Aβ production in APP-CHO cells. This was accompanied by decreased expression of β-secretase and lower production of sAPPβ (p < 0.05). However, expression of ADAM10 and production of sAPPα were not significantly affected. In contrast, MK-7 significantly decreased Aβ aggregation in a dose-dependent manner (p < 0.05). Conclusion: MK-7 exerts anti-amyloidogenic effects via decreased production and lower aggregation of Aβ into oligomers and fibrils. Therefore, dietary supplementation with MK-7 may be beneficial for the prevention of Alzheimer’s disease

    Stable release of enhanced organic solvent tolerant amylase from Bacillus amyloliquefaciens AMY02 under sub-merged fermentation

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    552-559This study has been performed to isolate a potential strain able to release the prolific amylase under non-aqueous conditions to meet the current demand in industries to substitute the amylase produced in aqueous media. A bacterial strain that produces organic solvent-stable amylase in the media containing 15% benzene was isolated from the soil. The recovered strain was identified to be Bacillus amyloliquefaciens AMY02by 16S rRNA sequencing. Under sub-merged fermentation, the optimized amylase release by this strain was found with the condition having starch (carbon source), pH 7.0, the temperature at 30°C for 48 h (incubation time). This optimized condition promoted the amylase production to be 2.04-fold higher than the culture was kept under standard condition with the basic media composition. Further, the stability of the enzyme in the presence of 20% organic solvents was assessed by incubating for 2 weeks. The enzyme was found to be active and stable in the presence of benzene, chloroform, o-xylene, and toluene. The higher organic solvent stability of this amylase production by B. amyloliquefaciens under sub-merged fermentation can be an alternative catalyst in non-aqueous media for industrial applications

    Stable release of enhanced organic solvent tolerant amylase from Bacillus amyloliquefaciens AMY02 under sub-merged fermentation

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    This study has been performed to isolate a potential strain able to release the prolific amylase under non-aqueous conditions to meet the current demand in industries to substitute the amylase produced in aqueous media. A bacterial strain that produces organic solvent-stable amylase in the media containing 15% benzene was isolated from the soil. The recovered strain was identified to be Bacillus amyloliquefaciens AMY02by 16S rRNA sequencing. Under sub-merged fermentation, the optimized amylase release by this strain was found with the condition having starch (carbon source), pH 7.0, the temperature at 30°C for 48 h (incubation time). This optimized condition promoted the amylase production to be 2.04-fold higher than the culture was kept under standard condition with the basic media composition. Further, the stability of the enzyme in the presence of 20% organic solvents was assessed by incubating for 2 weeks. The enzyme was found to be active and stable in the presence of benzene, chloroform, o-xylene, and toluene. The higher organic solvent stability of this amylase production by B. amyloliquefaciens under sub-merged fermentation can be an alternative catalyst in non-aqueous media for industrial applications

    Two aspects of decadal ENSO variability modulating the long-term global carbon cycle

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    The El Niño–Southern Oscillation (ENSO) drives variations in terrestrial carbon fluxes by affecting the terrestrial ecosystem via atmospheric teleconnections and thus plays an important role in interannual variability of the global carbon cycle. However, we lack such knowledge on decadal time scales, that is, how the carbon cycle can be affected by decadal variations of ENSO characteristics. Here we examine how, and by how much, decadal ENSO variability affects decadal variability of the global carbon cycle by analyzing a 1,801‐year preindustrial control simulation. We identify two different aspects, together explaining ~36% of the decadal variations in the global carbon cycle. First, climate variations induced by decadal ENSO‐like variability regulate terrestrial carbon flux and hence atmospheric CO2 on decadal time scales. Second, decadal changes in the asymmetrical response of the terrestrial ecosystem, resulting from decadal modulation of ENSO amplitude and asymmetry, rectify the background mean state, thereby generating decadal variability of land carbon fluxes
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