Development of Physical Activity Competence Test Battery and Evaluation Standards for Korean Children.

The purpose of this study is to develop a comprehensive and systematic method and standard for evaluating children's physical activity competency as a solution to the problem of increasing child obesity rates due to a decrease in physical activity among children. This study was used a cross-sectional study design. A literature review and Delphi survey were conducted to develop children's physical activity competency evaluation. The evaluation criteria were presented based on the measurement data of metropolitan area kindergarten students (228 subjects) on the 2016 winter vacation. Items in the evaluation of children's physical activity competency test battery include health physical strength, basic movement skills, physical activity habits, and physical activity attitudes. Physical fitness for health consisted of muscle strength and endurance (sit-up), flexibility (sit and reach, trunk lift) and body composition (BMI). Fundamental movement skills consisted of mobility (run, hop, jump), stability (static balance, dynamic balance), and control (throw kick). Physical activity habits consisted of the amount of daily steps (steps), exercise time, screen time, and sleep time. Physical activity attitudes consisted of preference, enjoyment, and confidence. The evaluation criteria for child physical activity competency test battery were presented in five stages, divided by age and gender. With the developed evaluation of children's physical activity competency, the overall level of physical fitness for health, fundamental movement skills, physical activity habits, and physical activity attitudes of kindergarteners in the metropolitan area could be confirmed, and standards were presented.

Setting Criterion for Adolescent Circuit Exercise Program.

The purpose of this study was to develop criteria for an adolescent circuit exercise program. The subjects of this study were 5268 middle- and high-school students. It consisted of three types of circuit exercise programs which were conducted in the physical education class. In the result of this study, we have found two significant finding. First, there were statistically significant differences by grade level and gender in three types of circuit exercise programs. Second, in order to improve the utilization rate and convenience of various adolescents' physical activity environments and the field of school physical education, the gender of each circuit exercise program was classified and the five-grade evaluation criteria were presented. The criteria for circuit exercise program developed in this study will be utilized for various youth physical activities to contribute to improving health and physical fitness. In addition, physical education teachers are expected to use this criteria as a standard for evaluating the physical fitness level of adolescents.

Comparison of Male Adolescents' Physical Fitness Using Physical Activity Promotion System and Circuit Exercise Program.

The purpose of this study is to compare the physical fitness level of adolescents through a physical fitness assessment and a circuit exercise program. A total of 142 middle school students participated. Physical education class consists of a physical fitness assessment, namely, physical activity promotion system (PAPS), and a circuit exercise program. The PAPS measurements include endurance, flexibility, strength, power, body mass index, and total score. The circuit exercise program consists of twist spine, hand walking, rolling squat, cross knee up, jumping and squat, and level-up pacer. First, there were significant differences in PAPS and circuit exercise program according to grade. Second, there was a significant difference in the results of the circuit exercise program according to the level of each physical fitness variable of PAPS. Third, significant correlations were found in the results of the PAPS and circuit exercise program. The use of a circuit exercise program to measure fitness for adolescents can offer convenience for school physical education and be of value as a measure of physical fitness for adolescents. In addition, the circulatory exercise programs used in this study are thought to be applicable to exercise prescriptions to improve endurance, strength, and BMI.

Augmented Hemodynamic Responses in Obese Young Men during Dynamic Exercise: Role of the Muscle Metaboreflex.

Studies found that cardiovascular responses to exercise are enhanced in individuals with obesity and are associated with a greater cardiac output (CO) response compared to normal weight controls. However, the mechanisms underlying these altered responses during dynamic exercise are not clear. We investigated whether the cardiovascular responses mediated by the muscle metaboreflex (MMR) activation are augmented in obese men during both static and dynamic exercise. Twenty males (10 obese (OG) and 10 non-obese (NOG)) were studied. Changes in CO, mean arterial pressure (MAP), and total vascular conductance (TVC) were compared between the two groups during dynamic handgrip exercise (DHE), post-exercise muscular ischemia (PEMI), and dynamic exercise corresponding to 40%, 60% and 80% workloads. Subjects completed 2 min of DHE at 30% of MVC, followed by 2 min of PEMI. MAP, CO, and TVC responses to DHE and dynamic exercise were significantly higher in OG, whereas there were no differences during PEMI. Increases in CO and MAP during mild to heavy dynamic exercise were seen in both groups, but the changes in these variables were greater in the OG. There were no significant differences in TVC between the two groups. Compared to NOG, the augmented blood pressure response to DHE and dynamic exercise in OG was associated with a greater increase in CO. Thus, the augmented CO and MAP responses were not associated with the activation of the MMR. Consequently, additional factors specific to obesity, such as the mechanoreflex, may have been involved.

Preparation and Characterization of Gas-Forming Polyacrylonitrile/Polymethylmethacrylate/Methylcyclohexane Nanocapsules for the Desorption of Optical Adhesive Films.

We herein report a simple approach to the preparation of gas-forming polyacrylonitrile/polymethyl-methacrylate/methylcyclohexane core-shell nanocapsules for the desorption of optical adhesive films. The proposed gas-forming core-shell nanocapsules are based on a shell structure composed of a polyacrylonitrile/polymethylmethacrylate copolymer, where the core contains vaporizable cyclic hydrocarbons (i.e., methylcyclohexane). These stable functional nanocapsules were spherical in shape, with an average particle size of ~110 nm. Interestingly, using the proposed synthetic method, it was also possible to prepare nanoparticles with varying particle sizes and copolymer ratios through a simple pre-emulsification stage and careful control of the monomer ratio employed. Upon mixing the resulting core-shell nanocapsules uniformly with the optical adhesive films, desorption was observed between layers following heat treatment. Furthermore, the high optical transmittance of the optical adhesive film was retained due to the small size of the core-shell nanoparticles. It was therefore apparent that the proposed method should be applicable for the preparation of future optical films where functional core-shell nanocapsules are required.

Microbubble-Triggered Spontaneous Separation of Transparent Thin Films from Substrates Using Evaporable Core-Shell Nanocapsules.

The spontaneous separation of a polymer thin film from a substrate is an innovative technology that will enable material recycling and reduce manufacturing cost in the film industry, and this can be applied in a wide range of applications, from optical films to wearable devices. Here, we present an unprecedented spontaneous strategy for separating transparent polymer films from substrates on the basis of microbubble generation using nanocapsules containing an evaporable material. The core-shell nanocapsules are prepared from poly(methyl methacrylate)-polyethyleneimine nanoparticles via the encapsulation of methylcyclohexane (MCH). A spherical nanostructure with a vaporizable core is obtained, with the heat-triggered gas release ability leading to the formation of microbubbles. Our separation method applied to transparent polymer films doped with a small amount of the nanocapsules encapsulating evaporable MCH enables spontaneous detachment of thin films from substrates via vacuum-assisted rapid vaporization of MCH over a short separation time, and clear detachment of the film is achieved with no deterioration of the inherent optical transparency and adhesive property compared to a pristine film.

Fabrication of Vertically Aligned Liquid Crystals Devices Using Nanoscale Self-Assembled Alignment Layers of Photoluminescent Pyrene Derivatives.

Nanoscale self-assembled molecular layers of 1-pyrene carboxylic acid, 1-pyrene butylic acid, and 1-amino pyrene were employed as photoluminescent alignment agents to form vertical arrays of liquid crystals (LCs). The LC device using alignment agent of 1-amino pyrene appeared to have a stable vertical alignment based on crossed polarization analysis. The electro-optical properties of the LCs fabricated using this self-assembled layer exhibited better performance than those of general LC cells containing a conventional polyimide layer. The proposed self-assembled alignment method is sufficient as a replacement for more commonly used polyimide layers, which require complex film forming processing and high production costs; conversely, the proposed technique allows for simple mixing using low concentrations of alignment agents (0.05 wt%). Moreover, as LCs were mixed with the pyrene derivatives, photoluminescence (PL) under ultraviolet (UV) light was exhibited. This proposed method has excellent LC alignment and PL property, both of which can be utilized in advanced display technologies for next-generation LC devices, such as polyimide-free alignment or color-filter-free color expression.

The inhibition of T-cells proliferation by mouse mesenchymal stem cells through the induction of p16INK4A-cyclin D1/cdk4 and p21waf1, p27kip1-cyclin E/cdk2 pathways.

Mesenchymal stem cells (MSCs) have been shown to down-regulate T-cell responses. However, the mechanisms underlying remain unknown. In this study, we report that BALB/c bone marrow-derived MSCs inhibit the proliferation of allogeneic T-cells in mixed lymphocyte reactions (MLR), This inhibition is dependent on cell-cell contact, and do not induce apoptosis. Furthermore, cell-cycle analyses reveal that T-cells, in the presence of MSCs, are arrested in the G0/G1 phase through. The blockage of phosphorylation of retinoblastoma protein (Rb), mediated by the p16(INK4A)-cyclin D1/cdk4 complex and p21(waf1), p27(kip1)-cyclin E/cdk2 complex pathway. Our results suggest that MSCs may perform a crucial function in the maintenance of immune homeostasis, via direct regulation of the clonal expansion of activated T-cells. The novel T-cell regulatory mechanism exhibited by MSCs may prove useful in a variety of therapeutic applications.