Contribution of AT1R mechanoactivation to the arterial myogenic response and its regulation by RGS5 protein in skeletal muscle arterioles

Although intracellular mechanisms underlying the arteriolar myogenic response have been well-defined, the mechanotransduction events transducing the mechanical stimulus remain unclear. Recently, ligand-independent activation of G protein-coupled receptors (in particular, the angiotensin II type 1 receptor; AT1R) has been suggested to play a major role in vascular smooth muscle mechanotransduction, thereby contributing to myogenic constriction. However, the downstream pathways following ligand-independent activation of the AT1R have not been clearly elucidated. Our studies provide pharmacological evidence that the mechanically activated AT1R generates diacylglycerol which in turn activates PKC that subsequently induces actin cytoskeleton reorganization for myogenic constriction. In terms of physiological roles, the arterial myogenic response acts to generate vascular tone, prevent capillaries from being damaged, and reduce edema due to high capillary hydrostatic pressure. Thus, an exaggerated AT1R-mediated myogenic constriction could conceivably contribute to vascular disorders. As a result, small arteries likely exhibit negative feedback regulatory mechanisms to prevent such an exaggerated myogenic response. In regard to this, we discovered that ligand-dependent or-independent activation of the AT1R causes trafficking of an important regulatory molecule, RGS5 (Regulators of G protein Signaling) protein, which may modulate Ang II or myogenic-mediated constriction by terminating Gq/11 protein-dependent signaling

High Percentage of Fat Calorie Intake may Result in Overweight Cyclists, Not Total Amount of Calorie Intake

Obesity has become a worldwide epidemic, representing a major health care challenge in the 21st century. There were numerous studies conducted to find a most effective intervention for reducing percentage of body fat. Among those interventions, exercise training has been proven to be a very effective strategy by enhancing the capacity to burn more body fat (fat oxidation capacity). However, there are the number of trained people with high % body fat even though they maintain high level of physical activity. PURPOSE: To compare various physiological variables including fat oxidation and diet patterns between normal and overweight trained cyclists. METHODS: Twelve well-trained amateur male cyclists aged 41.25 ± 1.65 yrs were assigned to either normal group (NO) and overweight group (OW) based on % body fat by hydrostatic measurement (19.56±1.08 vs. 25.23±1.34 % body fat) (each N=6). Respiratory exchange ratio (RER), blood pressure, blood lactate concentration, and heart rate were measured during the maximal test using a cycle ergometer. Dietry patterns were analyzed by three days diet log using computer software (DietPower). Independent t-test and two-way ANOVA with repeated measures were used to analyze data. RESULTS: There were no differences between NO and OW for age, height, weight, and body mass index. In addition, there were no differences between NO and OW for all cardiopulmonary fitness variables at rest and during maximal effort ergometer test. However, this study found that percentages of fat intake of OW was significantly higher compared to one of NO (OW: 41.67 ± 2.95 %; NO: 27.00 ± 2.25 %, p\u3c0.05). CONCLUSION: The findings of our study indicate that a greater body fat in some endurance-trained athletes would not be explained by cardiovascular, metabolic parameters and/or total caloric intake, but may be explained by high percentage of caloric intake from the fat

Test-retest reliability of power, pinch, and tripod grip strengths in male baseball players: a preliminary study

Since baseball players must grip and pinch the ball, grip strength is paramount. However, current assessments on various grip types need to be more comprehensive. This study aimed to determine the test-retest reliability of different handgrip strengths measured by a dynamometer connected to a player’s smartphone. Sixty male baseball players sponsored by secondary schools (middle- and high-schools) or colleges varying in age (12–22 years) were selected as participants. For male baseball players, three types of grip strengths were evaluated using a dynamometer and smartphone application: power, pinch, and tripod grip. The test was conducted thrice for each grip. Overall grip strength measurements showed slight decreases across tests and tended to increase with academic grade level. Tests 1 and 2 indicated good-to-excellent retest reliability for three grip strength positions by determining their intraclass correlation coefficients (ICCs) (middle-school power grip: 0.917 (0.644–0.973); collegiate pinch grip: 0.920 (0.770–0.970); high-school tripod grip: 0.929 (0.728–0.976)). In addition, these results determined moderate reliability compared to other grip strengths in the three groups (middle-school tripod grip from Tests 1 and 2: 0.779 (0.428–0.914); collegiate power grip from Tests 2 and 3: 0.738 (0.360–0.895)). This study concluded that the studied grip strength tests are reliable measurements, with an acceptable margin of error, for male baseball players from childhood to adulthood. Therefore, these handgrip strengths may be used as preliminary values to help discipline and rehabilitate baseball players and other athletes

Postnatal development of extracellular matrix and vascular function in small arteries of the rat

Introduction: Vascular extracellular matrix (ECM) is dominated by elastic fibers (elastin with fibrillin-rich microfibrils) and collagens. Current understanding of ECM protein development largely comes from studies of conduit vessels (e.g., aorta) while resistance vessel data are sparse. With an emphasis on elastin, we examined whether changes in postnatal expression of arteriolar wall ECM would correlate with development of local vasoregulatory mechanisms such as the myogenic response and endothelium-dependent dilation.Methods: Rat cerebral and mesenteric arteries were isolated at ages 3, 7, 11, 14, 19 days, 2 months, and 2 years. Using qPCR mRNA expression patterns were examined for elastin, collagen types I, II, III, IV, fibrillin-1, and -2, lysyl oxidase (LOX), and transglutaminase 2.Results: Elastin, LOX and fibrillar collagens I and III mRNA peaked at day 11–14 in both vasculatures before declining at later time-points. 3D confocal imaging for elastin showed continuous remodeling in the adventitia and the internal elastic lamina for both cerebral and mesenteric vessels. Myogenic responsiveness in cannulated cerebral arteries was detectable at day 3 with constriction shifted to higher intraluminal pressures by day 19. Myogenic responsiveness of mesenteric vessels appeared fully developed by day 3. Functional studies were performed to investigate developmental changes in endothelial-dependent dilation. Endothelial-dependent dilation to acetylcholine was less at day 3 compared to day 19 and at day 3 lacked an endothelial-derived hyperpolarizing factor component that was evident at day 19.Conclusion: Collectively, in the rat small artery structural remodeling and aspects of functional control continue to develop in the immediate postnatal period

Robust Pulse Rate Measurements from Facial Videos in Diverse Environments

Pulse wave and pulse rate are important indicators of cardiovascular health. Technologies that can check the pulse by contacting the skin with optical sensors built into smart devices have been developed. However, this may cause inconvenience, such as foreign body sensation. Accordingly, studies have been conducted on non-contact pulse rate measurements using facial videos focused on the indoors. Moreover, since the majority of studies are conducted indoors, the error in the pulse rate measurement in outdoor environments, such as an outdoor bench, car and drone, is high. In this paper, to deal with this issue, we focus on developing a robust pulse measurement method based on facial videos taken in diverse environments. The proposed method stably detects faces by removing high-frequency components of face coordinate signals derived from fine body tremors and illumination conditions. It optimizes for extracting skin color changes by reducing illumination-caused noise using the Cg color difference component. The robust pulse wave is extracted from the Cg signal using FFT–iFFT with zero-padding. It can eliminate signal-filtering distortion effectively. We demonstrate that the proposed method relieves pulse rate measurement problems, producing 3.36, 5.81, and 6.09 bpm RMSE for an outdoor bench, driving car, and flying drone, respectively

Screen media and non-screen media habits among preschool children in Singapore, South Korea, Japan, and Finland: Insights from an unsupervised clustering approach

The main purpose of the research was to describe the daily screen media habits and non-screen media habits like indoor and outdoor play, and sleep of preschool children aged 2 to 6 years from Singapore, South Korea, Japan, and Finland using a content-validated online questionnaire (SMALLQ®) and unsupervised cluster analysis. Unsupervised cluster analysis on 5809 parent-reported weekday and weekend screen and non-screen media habits of preschool children from the four countries resulted in seven emergent clusters. Cluster 2 ( n  = 1288) or the Early-screen media, screen media-lite and moderate-to-vigorous physical activity-lite family made up 22.2% and Cluster 1 ( n  = 261) or the High-all-round activity and screen media-late family made up 4.5%, respectively represented the largest and smallest clusters among the seven clusters that were emergent from the pooled dataset. Finland was best represented by Cluster 2 and Japan was best represented by Cluster 3 ( High-screen media-for-entertainment and low-engagement family ). Parents from Finland and Japan displayed greater homogeneity in terms of the screen media and non-screen media habits of preschool children than the parents from South Korea and Singapore. South Korea was best represented by Clusters 6 ( Screen media-physical activity-engagement hands-off family ) and 7 ( Screen media-lite, screen media-late and high-physical activity family ). Singapore was best represented by Clusters 4, 5, 6 and 7, and these clusters ranged from Low all-round activity-high nap time family to Screen media-lite, screen media-late and high-physical activity family . Future research should explore in-depth reasons for the across-country and within-country cluster characteristics of screen media and non-screen media habits among preschool children to allow for more targeted interventions

Secondary Phase Formation Mechanism in the Mo-Back Contact Region during Sulfo-Selenization Using a Metal Precursor: Effect of Wettability between a Liquid Metal and Substrate on Secondary Phase Formation

Recently, highly efficient CZTS solar cells using pure metal precursors have been reported, and our group created a cell with 12.6% efficiency, which is equivalent to the long-lasting world record of IBM. In this study, we report a new secondary phase formation mechanism in the back contact interface. Previously, CZTSSe decomposition with Mo has been proposed to explain the secondary phase and void formation in the Mo-back contact region. In our sulfo-selenization system, the formation of voids and secondary phases is well explained by the unique wetting properties of Mo and the liquid metal above the peritectic reaction (?-Cu6Sn5 → ϵ-Cu3Sn + liquid Sn) temperature. Good wetting between the liquid Sn and the Mo substrate was observed because of strong metallic bonding between the liquid metal and Mo layer. Thus, some ϵ-Cu3Sn and liquid Sn likely remained on the Mo layer during the sulfo-selenization process, and Cu-SSe and Cu-Sn-SSe phases formed on the Mo side. When bare soda lime glass (SLG) was used as a substrate, nonwetting adhesion was observed because of weak van der Walls interactions between the liquid metal and substrate. The Cu-Sn alloy did not remain on the SLG surface, and Cu-SSe and Cu-Sn-SSe phases were not observed after the final sulfo-selenization process. Additionally, Mo/SLG substrates coated with a thin Al2O3 layer (1-5 nm) were used to control secondary phase formation by changing the wetting properties between Mo and the liquid metal. A 1 nm Al2O3 layer was enough to control secondary phase formation at the CZTSSe/Mo and void/Mo interfaces, and a 2 nm Al2O3 layer was enough to perfectly control secondary phase formation at the Mo interface and Mo-SSe formation. © 2019 American Chemical Society.FALS