2,136 research outputs found

    Link Selection Algorithm of UWB Communications Considering Fading Statistics

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    This paper presents the link selection algorithm of Ultra Wide Band (UWB) communications considering fading statistics. In this algorithm, UWB devices decide the wireless link considering not only received signal strength but also fading statistics. Fading statistics follows the proposed channel model to the existence of line-of-sight (LOS)

    Correlation between thigh skinfold thickness and physical fitness factors in Korean adults and older individuals

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    Background: This cross-sectional epidemiological study aimed to compare the differences in physical fitness variables according to the skinfold thickness in the thigh area in adults and Korean older individuals. Methods: We analyzed data from the 2015 National Fitness Survey. A total of 4034 healthy adults (2442 men, 1592 women) with an average age of 38.19 ± 12.41 years and 880 healthy older subjects (369 men, 511 women) with an average age of 72.32 ± 5.49 years participated in this study. The skinfold thickness of the thigh was measured using a skinfold caliper (Dynatron, Dynatronics, USA). The participants underwent physical fitness tests, including the hand squeeze strength test, abdominal curl ups, standing double-leg long jump, 50 m shuttle run, sit and reach, and 20 m shuttle run for adult men and women. Older men and women performed the following tests: hand squeeze strength, abdominal curl ups, sit to stand test, single leg balance (open eyes), sit and reach, Apley scratch test for shoulder mobility, and 6-minute walk test. Independent t-tests and Pearson correlation analyses were used for the analysis. Results: Among the older men, significant differences were found in thigh skinfold thickness (t = –21.122, p < 0.001), abdominal curl ups (t = 2.165, p = 0.031), and sit and reach in men (t = 2.609, p = 0.009), and thigh skinfold (t = –29.611, p < 0.001), and Apley scratch test for shoulder mobility in women (t = –2.120, p = 0.034). There was a significant correlation between thigh skinfold thickness and physical activity (thigh skinfold thickness) in adult men (t = –54.202, p < 0.001), nondominant hand squeeze strength (t = 2.632, p = 0.009), abdominal curl ups (t = 4.292, p < 0.001), sit and reach (t = 3.063, p = 0.002), twenty meters shuttle run (t = 4.657, p < 0.001). However, no significant differences were found in dominant hand squeeze strength, standing double leg long jump, or 50 m shuttle run in men (p < 0.05). In adult women, there was a significant correlation between thigh skinfold thickness and physical activity (thigh skinfold thickness (t = –49.405, p < 0.001), dominant hand squeeze strength (t = 7.789, p < 0.001), nondominant hand squeeze strength (t = 6.944, p < 0.001), abdominal curl ups (t = 5.347, p < 0.001), standing double leg long jump (t = 5.890, p < 0.001), sit and reach (t = 5.384, p < 0.001), twenty meter shuttle run (t = 5.223, p < 0.001). However, no significant differences were found in fifty meter shuttle run in women (p < 0.05). Among older men, only single leg balance and sit and reach were correlated with thigh skinfold (single leg balance r = 0.169, p = 0.01; sit and reach r = –0.201, p = 0.001). In women, only abdominal curl ups, sit and reach, and Apley scratch test correlated with thigh skinfold (abdominal curl ups r = –0.088, p = 0.002; sit and reach r = –0.137, p = 0.002; Apley scratch test r = 0.090, p = 0.041). Conclusions: The effect of thigh skinfold thickness on the level of physical activity was more pronounced in adults than in older subjects. Our findings show that muscle strength and body fat in the lower extremities can affect overall muscle strength, endurance, and balance

    Effect of the glyceryl monooleate-based lyotropic phases on skin permeation using in vitro diffusion and skin imaging

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    AbstractGlyceryl monooleate (GMO) is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water. It is regarded as a permeation enhancer due to its amphiphilic property. Various phases of GMO/solvent system containing sodium fluorescein were prepared to compare permeability using confocal laser scanning microscopy (CLSM). GMO was melted in a vial in a water bath heated to 45 °C. Propylene glycol and hexanediol were homogeneously dissolved in the melted GMO. Sodium fluorescein in aqueous solution was diluted to various ratios and thoroughly mixed by an ultrasonic homogenizer. Each GMO/Solvent system with fluorescein was applied onto the epidermal side of excised pig skin and incubated overnight. CLSM was performed to observe how the GMO/solvent system in its different phases affect skin permeability. Cubic and lamellar phase formulations enhanced the fluorescein permeation through the stratum corneum. A solution system had the weakest permeability compared to the other two phases. Due to the amphiphilic nature of GMO, cubic and lamellar phases might reduce the barrier function of stratum corneum which was observed by CLSM as fluorescein accumulated in the dermis. Based on the results, the glyceryl monooleate lyotropic mixtures could be applied to enhance skin permeation in various topical and transdermal formulations

    YAF2 promotes TP53-mediated genotoxic stress response via stabilization of PDCD5

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    AbstractProgrammed cell death 5 (PDCD5) plays a crucial role in TP53-mediated apoptosis, but the regulatory mechanism of PDCD5 itself during apoptosis remains obscure. We identified YY1-associated factor 2 (YAF2) as a novel PDCD5-interacting protein in a yeast two-hybrid screen for PDCD5-interacting proteins. We found that YY1-associated factor 2 (YAF2) binds to and increases PDCD5 stability by inhibiting the ubiquitin-dependent proteosomal degradation pathway. However, knocking-down of YAF2 diminishes the levels of PDCD5 protein but not the levels of PDCD5 mRNA. Upon genotoxic stress response, YAF2 promotes TP53 activation via association with PDCD5. Strikingly, YAF2 failed to promote TP53 activation in the deletion of PDCD5, whereas restoration of wild-type PDCD5WT efficiently reversed the ineffectiveness of YAF2 on TP53 activation. Conversely, PDCD5 efficiently overcame the knockdown effect of YAF2 on ET-induced TP53 activation. Finally, impaired apoptosis upon PDCD5 ablation was substantially rescued by restoration of PDCD5WT but not YAF2-interacting defective PDCD5E4D nor TP53-interacting defective PDCD5E16D mutant. Our findings uncovered an apoptotic signaling cascade linking YAF2, PDCD5, and TP53 during genotoxic stress responses

    Titanium dioxide nanoparticles oral exposure to pregnant rats and its distribution

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    Background: Titanium dioxide (TiO2) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO2 nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial, and their internal distribution has not been investigated. Therefore, in this study, we investigated the potential effects of oral exposure to TiO2 nanoparticles and their distribution during pregnancy. TiO2 nanoparticles were orally administered to pregnant Sprague-Dawley rats (12 females per group) from gestation days (GDs) 6 to 19 at dosage levels of 0, 100, 300 and 1000 mg/kg/day, and then cesarean sections were conducted on GD 20. Results: In the maternal and embryo-fetal examinations, there were no marked toxicities in terms of general clinical signs, body weight, food consumption, organ weights, macroscopic findings, cesarean section parameters and fetal morphological examinations. In the distribution analysis, titanium contents were increased in the maternal liver, maternal brain and placenta after exposure to high doses of TiO2 nanoparticles. Conclusion: Oral exposure to TiO2 during pregnancy increased the titanium concentrations in the maternal liver, maternal brain and placenta, but these levels did not induce marked toxicities in maternal animals or affect embryo-fetal development. These results could be used to evaluate the human risk assessment of TiO2 nanoparticle oral exposure during pregnancy, and additional comprehensive toxicity studies are deemed necessary considering the possibility of complex exposure scenarios and the various sizes of TiO2 nanoparticles
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