Effects of volume-matched acute exercise on metacognition in late middle-aged adults: The roles of exercise intensity and duration.

Increasing studies have observed the benefit of acute exercise on core executive functions (EFs). However, the effects of high-order EFs (i.e., metacognition) are poorly investigated. Additionally, the beneficial effect varies depending on exercise-related variables (e.g., intensity, duration). Exercise volume, represented by exercise intensity and duration, is one approach to examine the relationship between acute exercise and metacognition. Therefore, this study aims to investigate the effects of acute exercise, involving three volume-matched evaluations, on metacognition in late middle-aged adults. It recruited 40 community-dwelling late middle-aged adults (22 females; Mage=61.05±4.17years). Its counterbalanced and repeated-measure experimental design included a control reading session and three exercise sessions: (1) acute moderate-intensity exercise for 30min, (2) higher-intensity exercise for 16min, and (3) lower-intensity exercise for 40min. After each session, all participants were asked to perform the Tower of London (TOL) task to assess their metacognition related to planning and problem-solving. This study showed that regardless of exercise intensity and duration variation, acute exercise led to higher move-related (i.e., total correct and move scores) and time-related (i.e., total executive and problem-solving times) scores but did not affect total initial time and violation-related scores compared to reading treatment. These findings suggest enhanced performance in metacognition after acute exercise regardless of its intensity and duration variation.

How to Defend COVID-19 in Taiwan? Talk about People's Disease Awareness, Attitudes, Behaviors and the Impact of Physical and Mental Health.

This study explored awareness, attitudes, and behavior in relation to Coronavirus Disease 2019 (COVID-19) prevention among Taiwanese citizens and their physical and mental health statuses. Through collection of 2132 questionnaire responses in field research, the present researchers analyzed the data using descriptive statistics and various approaches. In conclusion, the public's high level of willingness to share information, sufficient knowledge of and consensus on epidemic prevention between individuals and families, strict compliance with relevant regulations, effective preventive measures, and adequate public facilities have contributed to control of COVID-19. However, vigilance and awareness of the pandemic in some individuals, epidemic-prevention campaigns, and community-based preventive measures were insufficient. Some citizens subsequently suffered from headaches, anxiety, and mood instability. Furthermore, demographic variables (place of residence, sex, age, and occupation) and physical and mental health status produced various effects on citizens' awareness, attitude, and behavior regarding epidemic prevention as well as the perceived effect of COVID-19 on physical and mental health.

Effects of acute aerobic and resistance exercise on executive function: An ERP study.

OBJECTIVES: This study addressed the effects of acute, moderate-intensity aerobic and resistance exercise on the shifting aspect of cognition following a 30-min recovery period. It also explored the neuro-electrical activation that underlies the relationship between acute exercise and cognitive function through the examination of P3b and N1 components of event-related potentials. DESIGN: A counterbalanced, repeated-measures experimental design. METHODS: Thirty-five volunteer young adults completed two experimental sessions (i.e., acute aerobic exercise (AE) and resistance exercise (RE), matched in terms of intensity, and one reading session (control). The AE entailed cycling at 60-70% of maximal heart rate reserve for 30min. In the RE session, participants performed seven exercises with two sets of 8-12 repetitions at 70% of 10-repetition maximum. Each participant's neuro-electrical activation was recorded 30min after each session while s/he completed the task-switching test. RESULTS: After the 30-min recovery period, both AE and RE elicited shorter response times in global switching (ηp2=0.24) and local switching (ηp2=0.16) were observed when compared to control. Additionally, larger P3b amplitudes (but not N1 amplitudes) were evident in global switching (ηp2=0.15) and local switching (ηp2=0.16), regardless of exercise modality. CONCLUSIONS: The present findings suggest that acute exercise has positive effects on cognitive function. Exercise-induced alterations during the later stages of mental processing might result in superior performance. There were significant selective benefits in terms of brain function regardless of exercise modality.

Effects of Acute Aerobic and Resistance Exercise on Cognitive Function and Salivary Cortisol Responses.

This study aimed to determine the comparative effectiveness of aerobic vs. resistance exercise on cognitive function. In addition, salivary cortisol responses, as an indicator of arousal-related neuroendocrine responses, were assessed as a potential mechanism underlying the effects of these 2 modes of acute exercise on cognition. Forty-two young adults were recruited and performed the Stroop task after 1 session of aerobic exercise, resistance exercise, and a sedentary condition performed on separate days. Saliva samples were collected at baseline and immediately and 30 min after treatment conditions. Acute exercise, regardless of exercise modality, improved multiple aspects of cognitive function as reflected by the Stroop task. Cortisol responses were higher after both modes of acute exercise compared with the sedentary condition and were higher at baseline and 30 min afterward compared with immediately after treatment conditions. These findings suggest that acute exercise of moderate intensity facilitates cognitive function, and, although salivary cortisol is influenced by acute exercise, levels were not related to improvements in cognition.

Relationship between mode of sport training and general cognitive performance.

PURPOSE: To investigate whether athletes who engage in different modes of sports training correspondingly exhibit different patterns of performance on general cognition tasks. METHODS: Sixty participants were recruited into an endurance, motorically complex, or control group, and were administered a series of physical tests and neuropsychological assessments. RESULTS: Athletes in the endurance group demonstrated the highest levels of cardiovascular fitness and those in the motorically complex group exhibited the highest levels of motor fitness. Nonetheless, no differences in cognitive performance were observed between the 3 groups. CONCLUSION: These findings indicate that the mode of sport training, which results in either high cardiovascular or high motor fitness, bears no relationship to measures of general cognition in elite athletes. The present findings suggest that coaches and athletic trainers should be encouraged to monitor athletes' stress levels during training in order to maximize the beneficial effects of such training on general cognitive performance.

Acute exercise has a general facilitative effect on cognitive function: A combined ERP temporal dynamics and BDNF study.

This study examined whether acute moderate intensity exercise results in a general or selective improvement in cognitive function. In addition, multiple stimulus-locked ERP components and serum BDNF levels were assessed to investigate potential neurobiological mechanisms underlying acute exercise effects on select aspects of cognitive performance. Thirty young adults were recruited and participated in exercise and reading control sessions in a counterbalanced order. Following treatments, the Stroop task was administrated, and N1, N2, P3, and N450 components of the ERP waveform were recorded and analyzed. Additionally, blood samples were withdrawn immediately following exercise or rest conditions prior to administration of the Stroop task. Acute exercise facilitated response times for both Stroop congruent and incongruent task conditions, with a similar magnitude of improvement. Larger P3 and reduced N450 amplitudes as well as decreased N450 latency were observed following exercise, but no effects on N1 and N2 components were found. This dose of exercise also did not influence serum BDNF levels. These findings suggest that moderate intensity acute exercise results in a generalized rather than selective improvement in cognition. The facilitation may be related to an increase in attentional or neural resource allocation and conflict detection processes reflected by longer latency endogenous components (P3, N450), but is not influenced by earlier sensory and monitoring processes revealed by earlier ERP components or by serum levels of BDNF.

Exercise and fitness modulate cognitive function in older adults.

This study investigated the effects of acute exercise on cognitive function and the modulatory role of fitness in the relationship between exercise and cognition. Forty-six healthy older adults, categorized into higher or lower fitness groups, completed the Stroop test after both 30 min of aerobic exercise and a reading control with a counterbalanced order. Our findings demonstrated that acute exercise leads to general improvements in 2 types of cognitive functions and to specific improvements in executive function. Additionally, older adults with initially higher fitness levels experienced greater beneficial effects from acute exercise.

Structural differences in basal ganglia of elite running versus martial arts athletes: a diffusion tensor imaging study.

The aim of this study was to use diffusion tensor imaging (DTI) to characterize and compare microscopic differences in white matter integrity in the basal ganglia between elite professional athletes specializing in running and martial arts. Thirty-three young adults with sport-related skills as elite professional runners (n = 11) or elite professional martial artists (n = 11) were recruited and compared with non-athletic and healthy controls (n = 11). All participants underwent health- and skill-related physical fitness assessments. Fractional anisotropy (FA) and mean diffusivity (MD), the primary indices derived from DTI, were computed for five regions of interest in the bilateral basal ganglia, including the caudate nucleus, putamen, globus pallidus internal segment (GPi), globus pallidus external segment (GPe), and subthalamic nucleus. Results revealed that both athletic groups demonstrated better physical fitness indices compared with their control counterparts, with the running group exhibiting the highest cardiovascular fitness and the martial arts group exhibiting the highest muscular endurance and flexibility. With respect to the basal ganglia, both athletic groups showed significantly lower FA and marginally higher MD values in the GPi compared with the healthy control group. These findings suggest that professional sport or motor skill training is associated with changes in white matter integrity in specific regions of the basal ganglia, although these positive changes did not appear to depend on the type of sport-related motor skill being practiced.

Effect of acute exercise and cardiovascular fitness on cognitive function: an event-related cortical desynchronization study.

This study aimed to clarify the effects of acute exercise and cardiovascular fitness on cognitive function using the Stroop test and event-related desynchronization (ERD) in an aged population. Old adults (63.10 ± 2.89 years) were first assigned to either a high-fitness or a low-fitness group, and they were then subjected to an acute exercise treatment and a reading control treatment in a counterbalanced order. Alpha ERD was recorded during the Stroop test, which was administered after both treatments. Acute exercise improved cognitive performance regardless of the level of cognition, and old adults with higher fitness levels received greater benefits from acute exercise. Additionally, acute exercise, rather than overall fitness, elicited greater lower and upper alpha ERDs relative to the control condition. These findings indirectly suggest that the beneficial effects of acute exercise on cognitive performance may result from exercise-induced attentional control observed during frontal neural excitation.

Dose-response relation between exercise duration and cognition.

PURPOSE: The study aimed to provide evidence-based recommendations for the prescription of a single session of exercise to improve cognitive performance. In particular, the purpose was to determine the dose-response relation between exercise duration and cognitive performance for a moderate-intensity session of aerobic exercise. METHODS: Twenty-six healthy young men participated in a reading control treatment and three exercise treatments presented in a random order. The exercise treatments were designed on the basis of the American College of Sports Medicine guidelines and consisted of a 5-min warm-up, a 5-min cooldown, and cycling at moderate intensity (approximately 65% HR reserve) for 10, 20, or 45 min. The Stroop test was administrated after completion of each assigned treatment. RESULTS: Exercise at moderate intensity for 20 min resulted in significantly better cognitive performance, as assessed by shorter response time and higher accuracy. This result was found regardless of the type of cognitive function assessed. In addition, a curvilinear dose-response relation between exercise duration and cognitive performance was observed. CONCLUSIONS: An exercise session consisting of a 5-min warm-up, 20 min of moderate-intensity exercise, and a 5-min cooldown improves cognition, whereas shorter or longer durations of moderate exercise have negligible benefits. This study provides the foundation for the prescription of a single session of moderate exercise to facilitate cognitive function in healthy younger adults.

Effects of acute resistance exercise on cognition in late middle-aged adults: general or specific cognitive improvement?

OBJECTIVES: To evaluate the effect of acute resistance exercise on multiple cognitive measures in late middle-aged adults and to address the question of whether general or selective cognitive improvements occur. DESIGN: A counterbalanced repeated-measures experimental design. METHODS: Thirty adults (mean age=58.1 ± 3.0 years) were administered five different Stroop test conditions before and after a single bout of resistance exercise and after a no-treatment control. The resistance exercise protocol involved two sets of seven exercises performed at 70% of a 10-repetition maximum, with 30 and 60 s between each set and each exercise, respectively. RESULTS: The exercise treatment resulted in significantly enhanced performance across all Stroop conditions when compared with the control (p<.001). Furthermore, the effect of the exercise treatment on Stroop incongruent performance corresponded to the largest positive influence compared to the performance observed under the other four Stroop test conditions. CONCLUSIONS: These findings extend the current knowledge base by demonstrating that acute resistance exercise facilitates general cognition but has a more beneficial effect on cognition that involves executive control.

Executive function during acute exercise: the role of exercise intensity.

This study was designed to examine the modulation of executive functions during acute exercise and to determine whether exercise intensity moderates this relationship. Eighty college-aged adults were recruited and randomly assigned into one of the four following groups: control, 30%, 50%, and 80% heart rate reserve. The Wisconsin Card Sorting Test (WCST) was administered during each intervention. The results indicated that the majority of the WCST performances were impaired in the high exercise intensity group relative to those of the other three groups, whereas similar performance rates were maintained in the low- and moderate-intensity groups. These findings suggest that transient hypofrontality occurs during high-intensity exercise, but not during low- and moderate-intensity exercises. Future research aimed at employing the dual-mode theory, and applying the reticular-activating hypofrontality model is recommended to further the current knowledge.

Adjustable trapping position for single cells using voltage phase-controlled method.

We present an advanced technique improving upon the micron-sized particle trap integrated in biochip systems using a planar structure to generate an adjustable trapping position by utilizing voltage phase-controlled (VPC) method and negative dielectrophoresis (nDEP) theory in high conductivity physiological media. The designed planar and split structure is composed of independent components of measuring and trapping micro-electrodes. Through different voltage configurations on the device, the trapped position of single particles/cells was selected and adjusted in vertical and horizontal directions. The numerical simulations verify our theoretical predictions of the effects at the various voltages. It shows that the trapped position can be adjusted in the vertical (0 to 26 µm) and horizontal (0 to 74 µm) directions. In experiments, the single particles/cells is captured, measured, and then released, with the same process being repeated twice to demonstrate the precision of the positioning. The measurement results determined that particles at various heights result in different magnitude values, while the impedance error is less than 5% for the proposed electrode layout. Finally, the experiments are performed to verify that a particle/cell can be precisely trapped on the selected site in both the vertical and horizontal directions.

α-Glycosylation by D-glucosamine-derived donors: synthesis of heparosan and heparin analogues that interact with mycobacterial heparin-binding hemagglutinin.

Numerous biomolecules possess α-D-glucosamine as structural component. However, chemical glycosylations aimed at this backbone are usually not easily attained without generating the unwanted ß-isomer. We report herein a versatile approach in affording full α-stereoselectivity built upon a carefully selected set of orthogonal protecting groups on a D-glucosaminyl donor. The excellent stereoselectivity provided by the protecting group combination was found independent of leaving groups and activators. With the trichloroacetimidate as the optimum donor leaving group, core skeletons of glycosylphosphatidyl inositol anchors, heparosan, heparan sulfate, and heparin were efficiently assembled. The orthogonal protecting groups were successfully manipulated to further carry out the total syntheses of heparosan tri- and pentasaccharides and heparin di-, tetra-, hexa-, and octasaccharide analogues. Using the heparin analogues, heparin-binding hemagglutinin, a virulence factor of Mycobacterium tuberculosis, was found to bind at least six sugar units with the interaction notably being entropically driven.

Dose-response effect of acute resistance exercise on Tower of London in middle-aged adults.

The present research attempts to evaluate the dose-response relationship between acute resistance exercise and planning. Seventeen participants performed the Tower of London (TOL) in control condition and three different exercise intensity conditions (40%, 70%, and 100% 10-repetition maximal) in a counterbalanced order. The results revealed positive effects of an acute bout of resistance exercise on the TOL. Specifically, a curvilinear trend was observed between exercise intensity and TOL scores that measured performances of "correct" and "move," where moderate intensity demonstrated the most optimal performance compared with the other conditions. None of these differences were found in TOL scores that measure performances of "violation" and "planning speed." These results suggest that acute moderate intensity resistance exercise could facilitate planning-related executive functions in middle-aged adults.

Synthesis and regiochemistry of [60]fullerenyl 2-methylmalonate bisadducts and their facile electron-accepting properties.

A simple one-pot reaction using in situ chemically generated Na-naphthalenide as an electron reductant in the preferential generation of C(60)(2-) is described. Trapping of C(60)(2-) intermediate with 2 molar equiv of sterically hindered 2-bromo-2-methylmalonate ester afforded two singly bonded fullerenyl bisadducts C(60)[-CMe(CO(2)Et)(2)](2) in 35% and 7% yield, respectively. The regiochemistry of these two products was determined to be 1,4- and 1,16-bisadducts, respectively, by NMR, UV-vis-NIR, LCMS, and X-ray single crystal structural analysis. The minor 1,16-bisadduct 2 exhibits long wavelength absorption bands in the near-IR region and prominent electron-accepting characteristics as compared with those of the major 1,4-bisadduct and pristine C(60). As revealed by DFT calculation, we propose that the origin of these unusual characters of 2 arises from the moiety of [18pi]-trannulene, in close resemblance to that of the highly symmetrical emerald green 1,16,29,38,43,60-hexaadduct of C(60), EF-6MC(n). Accordingly, we anticipate a fast progressive formation of plausible 1,16-bisadduct-like intermediate moieties on a C(60) cage as the precursor structure leading to the formation of EF-6MC(n), by taking the corresponding regiochemistry and electronic properties into account.

Tunable two-dimensional photonic crystal couplers made of dielectric elastomer inclusions.

We propose a tunable directional coupler based on a two-dimensional photonic crystal made of dielectric elastomer rods embedded in air background. In the interaction region, the inclusions are a dielectric elastomer cylindrical actuator made of a hollow cylinder sandwiched between two compliant electrodes. By applying a voltage between the compliant electrodes, the radial strain of the silicon-made actuator and the coupling characteristics of the photonic crystal coupler are investigated. The coupling length of the photonic crystal coupler depends on the voltage applied between the electrodes, which is analyzed by the plane wave expansion method. Due to the radial strain of the dielectric elastomer under external voltage, the tunable photonic crystal coupler is realized. Numerical simulations obtained by the finite-difference time-domain method confirmed the feasibility of the tunable photonic crystal coupler.

Synthesis and characterization of ethylene glycol substituted poly(phenylene vinylene) derivatives.

We report the synthesis of a series of water-soluble, fluorescent, conjugated polymers via the Gilch reaction with an overall yield greater than 40%. The yield for the Gilch reaction decreases with the increase in the length of the side chain (ethylene glycol repeat units), presumably due to the steric effects inhibiting the linking of monomeric units. The hydrophilic side chain enhances the solubility of the polymer in water and concomitantly leads to a side-chain-dependent conformation and solvent-dependent quantum efficiency. An increase in the ethylene glycol repeat units on the polymer side chain structure results in changes in chain packing; hence, the crystallinity evolves from semicrystalline to liquid crystalline to completely amorphous. An increase in the length of the side chain leads to changes in the polymer-solvent interaction as manifested in the photophysical properties of these polymers. These novel polymers exhibit two glass transition temperatures, which can be readily rationalized by differences in microstructure when casted from hydrophobic and hydrophilic solvents. Cyclic voltammograms of polymer 1d-3d suggest two-electron transfer, as compared to P1 which has one complete redox pair. The potential of having a nanoscaled domain structure and stabilizing two electrons on a polymer chain signifies the potential of these polymers in fabricating electronic and photovoltaic devices.

Thermochromism of a poly(phenylene vinylene): untangling the roles of polymer aggregate and chain conformation.

We report reversible thermochromism of a conjugated polymer, poly{2,5-bis[3-(N,N-diethylamino)-1-oxapropyl]-1,4-phenylenevinylene} (DAO-PPV), in diluted solutions of toluene and 1,2-dichlorobenzene. By means of temperature- and solvent-dependent steady-state spectroscopy, picosecond time-resolved photoluminescence spectroscopy, and dynamic light scattering, we provide new insights into the role of polymer aggregates in defining the thermochromic behavior of PPVs. We find DAO-PPV to exhibit a low temperature state with vibronically structured red visible absorption and emission spectra. Structurally, this low temperature state is a densely packed and disordered polymer aggregate, which contains a fraction of well-ordered, packed polymer chains. These ordered regions serve as low energy trap sites for the more disordered regions in the aggregate, thus regulating the final emission of the aggregate and imposing a vibronically resolved emission spectrum, which is usually associated with emission from one or a few chromophores. The high temperature state of DAO-PPV is a loose aggregate, with structureless absorption and emission spectra in the green visible range. Structurally, the loose aggregate is a well-solvated aggregate retaining the physical dimension of the dense aggregate but for which interchain interactions are diminished with the increase of temperature. As a result, the spectroscopic behavior of the loose aggregate is very similar if not identical to that of the single polymer chain. Increased solubility untangles polymer aggregates into single, dispersed, polymer chains, as we demonstrate here for DAO-PPV in 1,2-dichlorobenzene and at high temperature.

Controlling layer thickness and photostability of water-soluble cationic poly(p-phenylenevinylene) in multilayer thin films by surfactant complexation.

In this work we build on prior studies of the novel water-soluble cationic conjugated polymer known as "P2" (poly{2,5-bis[3-( N, N, N-triethylammonium bromide)-1-oxapropyl]-1,4-phenylenevinylene}) with a focus on its incorporation into thin films for such applications as photovoltaics or electroluminescent devices. Multilayer assemblies were constructed using P2, the anionic surfactant sodium dodecyl sulfate (SDS), and the polyanion poly(sodium 4-styrene-sulfonate) (PSS) using the technique of layer-by-layer electrostatic self-assembly (LBL-ESA). SDS was observed to affect the layer thicknesses and absorbance characteristics of the films. We show that the optical properties and photo-oxidative resistance can be improved by varying the SDS content in the assemblies. Specifically, the surfactant-complexed poly( p-phenylenevinylene) (PPV) shows an enhanced absorption at longer wavelengths as well as improved photostability. Therefore, our work may have broad implications on the development of stable PPV-based materials in general and their efficient integration into thin films technologies.