An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding

The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators

Physiological Functions of Mitochondrial Reactive Oxygen Species

Mitochondria are the major energy producers within a cell in the form of adenosine triphosphate by oxidative phosphorylation. Normal mitochondrial metabolism inevitably generates reactive oxygen species (ROS), which have been considered to solely cause cellular damage. Increase of oxidative stress has been linked to various pathologies. Thus, mitochondrial ROS (mROS) were basically proposed as byproducts of oxidative metabolism, which undergo normalized by antioxidant enzymes. However, the mROS have extensively been esteemed to function as signalling molecules to regulate a wide variety of physiology. These phenomena are indeed dependent on mitochondrial redox status, which is dynamically altered under different physiological and pathological conditions. The oxidative stress is incurred by which the redox status is inclined to exceeded oxidation or reduction. Here, we attempt to integrate the recent advances in our understanding of the physiological functions of mROS

Ixeris dentata (Thunb) Nakai attenuates cognitive impairment in MPTP-treated mouse model of Parkinson's disease

Purpose: To evaluate the cognition-enhancing effect of Ixeris dentata (Thunb) Nakai in a mouse model of Parkinson's disease (PD). Methods: MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced mouse model of PD was used to evaluate the effect of Ixeris dentata (IDE) extract on the alteration of behavioral responses using rotarod and passive avoidance tests. The effect of IDE on oxidative stress levels were analyzed based on superoxide dismutase (SOD) and catalase (CAT) enzyme levels, and lipid peroxidation (LPO) in brain tissues. Results: MPTP (20 mg/kg, ip)-induced mice resulted in a significant (p < 0.01) behavioral deficiencies in locomotor behavior (from 53.15 ± 1.01 to 23.56 ± 1.04) and cognitive functions (from 297 ± 2.47 to 201.17 ± 3.23 s) compared with their respective control groups. Administration of IDE (20, 40 and 80 mg/kg, po) for three weeks significantly and dose-dependently improved (p < 0.001 at 80 mg/kg) locomotor and cognitive deficits in MPTP- treated mice. IDE treatment also significantly (p < 0.01 at 80 mg/kg) inhibited decrease in superoxide dismutase and catalase enzyme activities, and lipid peroxides in MPTP-treated mice in brain tissues. Conclusion: IDE exhibits good protection against MPTP-induced behavioral deficits via potential antioxidant defense mechanisms. Therefore, IDE could potentially be developed as a therapeutic approach for the treatment of neurodegenerative diseases. Keywords: Ixeris dentata, Neurodegenerative disease, MPTP, Parkinson's disease, Oxidative stres

Anti-oxidative and anti-neuroinflammatory effects of ethyl acetate extract fractions of Suaeda asparagoides MIq

Purpose: To evaluate the in vitro antioxidant and anti-neuroinflammatory effects of Suaeda asparagoides ethylacetate extract (SAE) in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells.Methods: The antioxidative activity of SAE was evaluated by measuring 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity  spectrometrometrically. Cell viability was evaluated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay, while LPS-stimulated BV-2 microglia were used to study the expression and production of inflammatory mediators, including nitric oxide (NO), inducible NO synthase (iNOS) and tumor necrosis alpha (TNF-α).Results: Pretreatment with SAE prior to LPS treatment significantly inhibited excessive production of NO (p < 0.001 at 20, 40, 80 and 100 μg/mL) in a dose-dependent manner, and was associated with down-regulation of expression of inducible nitric oxide synthase (iNOS). SAE also suppressed the LPSinduced increase in TNF-α level (p < 0.01at concentrations of 40 and 80 μg/mL) in BV-2 cells. Furthermore, DPPH-generated free radicals were inhibited by SAE in a concentration-dependent manner.Conclusion: These results indicate that SAE possesses strong anti-oxidant properties, and inhibits excessive production of pro-inflammatory mediators, including NO, iNOS and TNF-α, in LPS-stimulated BV-2 cellsKeywords: Suaeda asparagoides, DPPH, Anti-inflammatory activity, Microglial cells, iNOS, TNF-

The characteristic comparison of the accelerometer and the gyroscope in the measurement of human body sway

This study investigated the human body sway measuring instruments. An accelerometer and a gyroscope were used to examine patients with postural control related diseases in many studies. Some studies used either an accelerometer or a gyroscope attached to the head, chest, or waist to obtain the balance assessment parameters of body sway such as area, direction, etc. The purpose of this study is to identify the reliability between both sensors in human body sway analysis by assuming the human body sway as a simple pendulum model, and suggest an optimal measurement method using the acceleration and the gyroscope. The characteristic differences between the accelerometer and the gyroscope were illustrated, focusing mainly on the differences with respect to the position of the sensors. We confirmed that the magnitude, instead of three axis vector information, may be more useful in the body sway analysis

Treadmill Exercise Alleviates Aging-induced Apoptosis in Rat Cardiac Myocytes

SummaryBackgroundThe incidence and prevalence of heart failure increases with age. Cardiomyocyte apoptosis contributes to the pathogenesis of heart failure. In the end-stage of human heart failure, increased cardiomyocyte apoptosis is observed. Exercise training is one of the nonpharmacological treatments for chronic heart failure.MethodsIn the present study, we investigated the effect of treadmill exercise on the aging-induced apoptosis within cardiac myocytes in relation to the expression of heat shock protein 70 (HSP70) using rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and Western blotting for the expression of Bcl-2, Bax, HSP70, and phosphorylated p38 (p-p38) in the cardiac myocardium were conducted.ResultsAging induced apoptosis in the myocardium, which was confirmed by increased TUNEL-positive cells and the enhancement of Bax. Expression of HSP70 was suppressed and p-p38 expression was enhanced by aging. Treadmill exercise alleviated aging-induced apoptosis with enhancing HSP70 expression and suppressing p-p38 expression in the cardiac myocytes.ConclusionBased on the present results, it can be inferred that treadmill exercise can provide a cardioprotective effect on aging-induced apoptosis through the enhancement of HSP70 expression in the heart. Thus, regular exercise may be a useful strategy for preventing heart problems in the elderly

Effect of Si and SiO 2

Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition system. Si substrate, SiO2 thin film deposited Si substrate (SiO2 substrate), and quartz substrate were employed to elucidate the effect of substrate on the formation of carbon coils. The characteristics (formation densities, morphologies, and geometries) of the deposited carbon coils on the substrate were investigated. In case of Si substrate, the microsized carbon coils were dominant on the substrate surface. While, in case of SiO2 substrate, the nanosized carbon coils were prevailing on the substrate surface. The surface morphologies of samples were investigated step by step during the reaction process. The cause for the different geometry formation of carbon coils according to the different substrates was discussed in association with the different thermal expansion coefficient values of Si and SiO2 substrates and the different etched characteristics of Si and SiO2 substrates by SF6 + H2 flow

Characteristics and Trends of Strawberry Cultivars throughout the Cultivation Season in a Greenhouse

Each strawberry (Fragaria × ananassa) cultivar has its own growth and yield characteristics. However, the characteristics of many cultivars have not been determined at a consistent time and place, making direct comparative analysis difficult. The objective of this study was to identify characteristics and trends of five Korean strawberry cultivars in the same environment during an entire season. Therefore, environmental factors such as daily average air temperature, daily average relative humidity, daily average solar radiation, daily soil temperature, daily soil water content, daily soil electrical conductivity (EC), plant growth characteristics such as the number of leaves, plant height, leaf length, leaf width, and crown diameter, and productivity characteristics such as flowering and fruiting were measured to investigate the possible correlations of the data over one season. The vegetative growth of “Seolhyang” and “Keumsil” was greater than that of “Jukhyang” and “Maehyang”. The yield of “Arihyang” was greater than that of all other cultivars. “Arihyang” also presented the greatest weight per number of fruits. Among environmental factors, higher variability in air temperature and soil water content was correlated to lower total fresh weight in the following week at different degrees for each cultivar. Among the cultivars, the time to the first flowering was delayed by about seven days when the number of leaves increased by one and was reduced by one day per 1 cm increase in plant height. The total fresh weight was enhanced up to 271 g per experimental unit, while the average number of leaves increased by one. The results indicate that the data can be used by those who need information regarding the characteristics of the strawberry cultivars through direct comparative analysis