Slowed response to peripheral visual stimuli during strenuous exercise

Recently, we proposed that strenuous exercise impairs peripheral visual perception because visual responses to peripheral visual stimuli were slowed during strenuous exercise. However, this proposal was challenged because strenuous exercise is also likely to affect the brain network underlying motor responses. The purpose of the current study was to resolve this issue. Fourteen participants performed a visual reaction-time (RT) task at rest and while exercising at 50% (moderate) and 75% (strenuous) peak oxygen uptake. Visual stimuli were randomly presented at different distances from fixation in two task conditions: the Central condition (2° or 5° from fixation) and the Peripheral condition (30° or 50° from fixation). We defined premotor time as the time between stimulus onset and the motor response, as determined using electromyographic recordings. In the Central condition, premotor time did not change during moderate (167 ± 19 ms) and strenuous (168 ± 24 ms) exercise from that at rest (164 ± 17 ms). In the Peripheral condition, premotor time significantly increased during moderate (181 ± 18 ms, P < 0.05) and strenuous exercise (189 ± 23 ms, P < 0.001) from that at rest (173 ± 17 ms). These results suggest that increases in Premotor Time to the peripheral visual stimuli did not result from an impaired motor-response network, but rather from impaired peripheral visual perception. We conclude that slowed response to peripheral visual stimuli during strenuous exercise primarily results from impaired visual perception of the periphery

Regioselective chemisorption-induced separate deposition of two types of metal nanoparticles on TiO2

The discovery of the excellent thermal catalytic activity of Au nanoparticles (NPs) for CO oxidation (Haruta et al., 1987 [1]) triggered intensive research on thermal and visible photo-catalysis based on these NPs (Ref. [2]). Recently, catalysts containing two types of metal NPs loaded onto a TiO2 support, i.e., NPs consisting of a separate Au photocatalyst (average size: 13 nm) and another noble metal, were developed as highly efficient visible photocatalysts for several important chemical reactions (Tanaka et al., 2013 [3]). Although the visible photocatalytic activities of Au NPs increase as their particle size decreases (Teranishi et al., 2016 [4]), small Au NPs with a narrow size distribution could not be deposited previously because these NPs underwent dissolution and redeposition (Tanaka et al., 2013 [3]). Additionally, little is known about the mechanism of separate deposition. Herein we report a new method involving the chemisorption and subsequent NaBH4 reduction of Au(III) complex ions on TiO2–Pt. Our method enables the deposition of small Au NPs with a narrow size distribution (average size: 2.5 nm) on the TiO2 surface in TiO2–Pt (Au/TiO2–Pt). The separate deposition was rationalized in terms of the regioselective chemisorption of Au(III) complex ions on the surface of TiO2 by measuring the Au(III) complex ion adsorption. • The chemisorption and subsequent NaBH4 reduction of Au(III) complex ions on TiO2-Pt led to the deposition of small Au NPs with a narrow size distribution on the TiO2 surface of TiO2-Pt. These NPs differ from those obtained by using the existing CPH method, which produced Au NPs with a large particle size and a wide size distribution. • The separate deposition was rationalized in terms of the regioselective chemisorption of Au(III) complex ions on the TiO2 surface, although the mechanism of the CPH method was not disclosed. • Further application of the regioselective chemisorption-induced separate deposition may enable the development of new catalysts. Method name: Regioselective chemisorption-induced separate deposition, Keywords: Nanocomposite, Separate deposition, Metal complex, Regioselective chemisorptio

The effects of exercise under hypoxia on cognitive function.

Increasing evidence suggests that cognitive function improves during a single bout of moderate exercise. In contrast, exercise under hypoxia may compromise the availability of oxygen. Given that brain function and tissue integrity are dependent on a continuous and sufficient oxygen supply, exercise under hypoxia may impair cognitive function. However, it remains unclear how exercise under hypoxia affects cognitive function. The purpose of this study was to examine the effects of exercise under different levels of hypoxia on cognitive function. Twelve participants performed a cognitive task at rest and during exercise at various fractions of inspired oxygen (FIO2: 0.209, 0.18, and 0.15). Exercise intensity corresponded to 60% of peak oxygen uptake under normoxia. The participants performed a Go/No-Go task requiring executive control. Cognitive function was evaluated using the speed of response (reaction time) and response accuracy. We monitored pulse oximetric saturation (SpO2) and cerebral oxygenation to assess oxygen availability. SpO2 and cerebral oxygenation progressively decreased during exercise as the FIO2 level decreased. Nevertheless, the reaction time in the Go-trial significantly decreased during moderate exercise. Hypoxia did not affect reaction time. Neither exercise nor difference in FIO2 level affected response accuracy. An additional experiment indicated that cognitive function was not altered without exercise. These results suggest that the improvement in cognitive function is attributable to exercise, and that hypoxia has no effects on cognitive function at least under the present experimental condition. Exercise-cognition interaction should be further investigated under various environmental and exercise conditions

The joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) in middle-aged and older males

Abstract Background This retrospective study evaluated the influence of the joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) during a 6-year follow-up period in middle-aged and older males. Methods The study population included 303 males without a history of cardiovascular disease, stroke, renal dysfunction, or dialysis treatment. Their lifestyle behaviors regarding exercise and physical activity were evaluated using a standardized self-administered questionnaire. The participants were divided into four categories according to the performance or non-performance of habitual exercise and the presence or absence of hyperglycemia. Results After 6 years, 32 subjects (10.6%) developed CKD (estimated glomerular filtration rate < 60 ml/min/1.73 m2 and/or proteinuria). The cumulative incidence of CKD was significantly higher among subjects who did not perform habitual exercise and hyperglycemic subjects (log-rank test: p < 0.05, respectively). According to a Cox proportional hazards model, the hazard ratio (HR) for the incidence of CKD in subjects with a normal glucose tolerance (NGT) who did not perform habitual exercise (HR = 2.82, 95% confidence of interval (CI) = 1.07–7.36, p = 0.034) and that in hyperglycemic subjects who did not perform habitual exercise (HR = 5.89, 95% CI = 1.87–16.63, p = 0.003) were significantly higher in comparison to the subjects with a NGT who performed habitual exercise. Conclusions These results suggest that the habitual exercise and good glycemic control and their combination were associated with the incidence of CKD

Hypertension and hyperglycemia and the combination thereof enhances the incidence of chronic kidney disease (CKD) in middle-aged and older males

Aim: Chronic kidney disease (CKD) may be an etiologic cause of aging, hypertension, diabetes mellitus (DM), and metabolic syndrome. However, the influence of these cardiovascular risk factors and their combination on the development of CKD remains controversial. This retrospective study evaluated the influence of cardiovascular risk factors and their combination on the incidence of CKD during a 6-year follow-up period in middle-aged and older males. Methods: The subjects were 303 males without a history of cardiovascular disease, stroke, renal dysfunction, or dialysis treatment. A biochemical analysis, blood pressure (BP) analysis, and anthropometry measurements were performed every year, and the classification of CKD was also assessed based on the estimated glomerular filtration rate (<60 ml/min/1.73 m2) and/or presence of proteinuria. Results: After 6 years, the incidence of CKD was noted in 32 subjects. According to a multivariable analysis, hypertension (hazard ratio [HR]: 3.95, 95% confidence of interval [CI]: 1.64–9.49, p = 0.002) and hyperglycemia (HR: 3.27, 95% CI: 1.42–7.56, p = 0.006) were significantly associated with the incidence of CKD. According to a Cox proportional hazards model, the HR for the incidence of CKD was significantly higher in the combination of high-normal BP/hypertension and impaired fasting glucose/DM group than in the combination of normotensive and normal glucose tolerance group (HR: 7.16, 95% CI: 2.43–17.25, p = 0.001). Conclusions: These results suggest that the hypertension and hyperglycemia and their combination may be associated with the incidence of CKD

Lifestyle Intervention Involving Calorie Restriction with or without Aerobic Exercise Training Improves Liver Fat in Adults with Visceral Adiposity

Objective. To evaluate the effect of calorie restriction-induced weight loss with or without aerobic exercise on liver fat. Methods. Thirty-three adults with visceral adiposity were divided into calorie restriction (CR; n = 18) or CR and aerobic exercise (CR + Ex; n = 15) groups. Target energy intake was 25 kcal/kg of ideal body weight. The CR + Ex group had a targeted exercise time of 300 min/wk or more at lactate threshold intensity for 12 weeks. Results. Reductions in body weight (CR, -5.3 ± 0.8 kg; CR + Ex, -5.1 ± 0.7 kg), fat mass (CR, -4.9± 0.9 kg; CR + Ex, -4.4 ± 0.6 kg), and visceral fat (CR, -24 ± 5 cm2; CR + Ex, -37 ± 5 cm2) were not statistically different between groups. Liver fat decreased significantly in both groups, with no difference between groups. Change in maximal oxygen uptake was significantly greater in the CR + Ex group than in the CR group (CR, -0.7 ± 0.7 mL/kg/min; CR + Ex, 2.9 ± 1.0 mL/kg/min). Conclusion. Both CR and CR + Ex resulted in an improved reduction in liver fat; however, there was no additive effect of exercise training

The Relationship between Running Velocity and the Energy Cost of Turning during Running

<div><p>Ball game players frequently perform changes of direction (CODs) while running; however, there has been little research on the physiological impact of CODs. In particular, the effect of running velocity on the physiological and energy demands of CODs while running has not been clearly determined. The purpose of this study was to examine the relationship between running velocity and the energy cost of a 180°COD and to quantify the energy cost of a 180°COD. Nine male university students (aged 18–22 years) participated in the study. Five shuttle trials were performed in which the subjects were required to run at different velocities (3, 4, 5, 6, 7, and 8 km/h). Each trial consisted of four stages with different turn frequencies (13, 18, 24 and 30 per minute), and each stage lasted 3 minutes. Oxygen consumption was measured during the trial. The energy cost of a COD significantly increased with running velocity (except between 7 and 8 km/h, p = 0.110). The relationship between running velocity and the energy cost of a 180°COD is best represented by a quadratic function (y = −0.012+0.066x +0.008x², [r = 0.994, p = 0.001]), but is also well represented by a linear (y = −0.228+0.152x, [r = 0.991, p<0.001]). These data suggest that even low running velocities have relatively high physiological demands if the COD frequency increases, and that running velocities affect the physiological demands of CODs. These results also showed that the energy expenditure of COD can be evaluated using only two data points. These results may be useful for estimating the energy expenditure of players during a match and designing shuttle exercise training programs.</p></div