Local and Remote Ischemic Preconditioning Improves Sprint Interval Exercise Performance in Team Sport Athletes.

The aim of this study was to investigate the effects of local (LIPC) and remote (RIPC) ischemic preconditioning on sprint interval exercise (SIE) performance. Fifteen male collegiate basketball players underwent a LIPC, RIPC, sham (SHAM), or control (CON) trial before conducting six sets of a 30-s Wingate-based SIE test. The oxygen uptake and heart rate were continuously measured during SIE test. The total work in the LIPC (+2.2%) and RIPC (+2.5%) conditions was significantly higher than that in the CON condition (p < 0.05). The mean power output (MPO) at the third and fourth sprint in the LIPC (+4.5%) and RIPC (+4.9%) conditions was significantly higher than that in the CON condition (p < 0.05). The percentage decrement score for MPO in the LIPC and RIPC condition was significantly lower than that in the CON condition (p < 0.05). No significant interaction effects were found in pH and blood lactate concentrations. There were no significant differences in the accumulated exercise time at ≥80%, 90%, and 100% of maximal oxygen uptake during SIE. Overall, both LIPC and RIPC could improve metabolic efficiency and performance during SIE in athletes.

Acute effect of inspiratory resistive loading on sprint interval exercise performance in team-sport athletes.

This study examined acute effects of inspiratory resistive loading (IRL) during rest intervals on sprint interval exercise (SIE) performance. In a randomized crossover design, nine collegiate basketball players performed IRL (15 cmH2O) or passive recovery (CON) at 5-min rest intervals during and immediately after 6 sets of a 30-s SIE test. Performance, muscular oxygenation of vastus lateralis, blood lactate and pH were measured at each condition. Blood lactate at 5-min (-20.5 %) and 20-min (-21.3 %) after SIE were significantly lower in IRL than in CON. The pH at 5-min after SIE was significantly higher in IRL than in CON (+0.8 %, p <  0.05). However, the total work in IRL was significantly lower than in CON (-2.7 %, p <  0.05). Average changes in total hemoglobin at rest intervals in IRL were significantly lower than in CON (-34.5 %, p <  0.05). The IRL could attenuate exercise-induced metabolic acidosis; however, the decreased blood flow at rest intervals might increase the physical challenge in SIE.

Engineering Antifouling and Antibacterial Stainless Steel for Orthodontic Appliances through Layer-by-Layer Deposition of Nanocomposite Coatings.

In this study, a nanocomposite coating composed of polydopamine, functionalized poly(3,4-ethylenedioxythiophene) (PEDOT), and silver nanoparticles (AgNPs) was synthesized through layer-by-layer deposition. Biomimitic polydopamine and hydroxyl-functionalized PEDOT were used to enhance the adhesion strength. The deposition of PEDOT functionalized with zwitterionic phosphorylcholine can contribute to the antifouling property. After immersion in the AgNO3 solution, Ag+ ions were adsorbed on PEDOT films and further reduced to form AgNPs spontaneously, which conferred antibacterial properties on these nanocomposite films. Escherichia coli and Streptococcus mutans were chosen to represent two common Gram-negative and Gram-positive oral pathogens. We further conducted inductively coupled plasma mass spectrometry to confirm that the Ag+ ions released from these nanocomposite films did not exert adverse effects on the human body. These results suggested that, when applied to stainless steel orthodontic appliances, these durable antifouling and antibacterial coatings may be useful for avoiding bacterial infection.

Validity and reliability of the 3-min all-out running test to measure critical velocity in hot environments.

This study's aim was to investigate the test-retest reliability of the 3-min all-out running test (3MRT) in hot environments. Twelve male sprinters (age 21.2 ± 1.8 years; height 1.78 ± 0.01 m; weight 71.0 ± 1.6 kg; [Formula: see text] 55.0 ± 1.0 mL kg-1 min-1) performed an incremental exercise test in a laboratory, during which the first and second ventilatory thresholds (VT1 and VT2) and [Formula: see text] were determined. In addition, they performed two 3MRTs on an outdoor track in a hot environment, during which the critical velocity (CV) and anaerobic capacity (D') were estimated. Significant reproducibility was found in CV and D' (ICC = 0.74 and 0.61, P < 0.05). The average CV in 3MRTs (3.09 ± 0.13 m s-1) correlated significantly with VT1 (3.13 ± 0.07 m s-1, P < 0.05). The 3MRT is a reliable tool for measuring CV and D', while CV from 3MRT in a hot environment was identical to VT1.

Physiological Adaptations to Sprint Interval Training with Matched Exercise Volume.

PURPOSE: This study aimed to determine how high-intensity interval training (HIIT) protocols featuring matched times but distinct sprint durations affect cardiorespiratory and metabolic responses and performance. METHODS: Thirty-eight recreationally active men (age 21 ± 2 yr) were assigned to one of three interval training groups: long-duration high-intensity (HIIT60s; 8 × 60 s at 85%-90% V˙O2max; 120-s recovery at 30% V˙O2max), short-duration high-intensity (HIIT10s; 48 × 10 s at 85%-90% V˙O2max; 20-s recovery at 30% V˙O2max), and control (regular physical activity without HIIT). Before and after a 4-wk training period (three sessions per week), participants performed graded exercise tests and repeated sprint tests, based on which their aerobic and anaerobic capacities were assessed. Skinfold thickness, blood, and metabolic responses were also measured before and after intervention. RESULTS: After the 4-wk training period, V˙O2max was significantly increased (P < 0.01) in HIIT60s (52 ± 9 vs 61 ± 12 mL·kg·min) and HIIT10s (53 ± 10 vs 61 ± 10 mL·kg·min), but there were no changes in the control group (50 ± 7 vs 52 ± 7 mL·kg·min). Skinfold thickness in the abdomen and thigh did not differ significantly among the groups, but a significantly greater decrease in 14%-25% in HIIT60s and a decrease in 20% in HIIT10s after training (P < 0.05) were found. Blood lactate, total cholesterol, triglyceride, cortisol, and insulin concentrations were not significantly different among the three groups (P > 0.05), but testosterone concentration in the HIIT10s was higher after training than before (P < 0.05). CONCLUSION: The higher incremental aerobic performance and lower skinfold thickness in HIIT60s versus HIIT10s reflected similar adaptations, but the higher repeated sprint performance was observed only in responses to HIIT60s, which may elicit greater anaerobic adaptations.

Rapid fabrication method of a microneedle mold with controllable needle height and width.

The main issue of transdermal drug delivery is that macromolecular drugs cannot diffuse through the stratum corneum of skin. Many studies have pursued micro-sized needles encapsulated with drugs to overcome this problem, as these needles can pierce the stratum corneum and allow drugs to enter the circulatory system of the human body. However, most microneedle fabrication processes are time-consuming and require expensive equipment. In this study, we demonstrate a rapid method for fabricating a microneedle mold using drawing lithography and a UV-cured resin. The mold was filled with a water-soluble material, polyvinylpyrrolidone (PVP), which was then demolded to produce a water-soluble microneedle array. The results of an in vitro skin insertion test using PVP microneedles and pig ear skin demonstrated the feasibility of the microneedle mold. In addition, by controlling the viscosity of the UV-cured resin through various heat treatments, microneedles with different heights and aspect ratios were produced. Compared with other methods, this technology significantly simplifies and accelerates the mold fabrication process. In addition, the required equipment is relatively simple and inexpensive. Through this technology, we can rapidly fabricate microneedle molds with controllable dimensions for various applications.

Caffeine ingestion improves power output decrement during 3-min all-out exercise.

PURPOSE: To investigate the effect of caffeine ingestion on the 3-min all-out test (3MT) performance and plasma electrolytes in athletes. METHODS: Fifteen collegiate male basketball players were recruited and completed two trials separated by at least 1 week in caffeine (CAF, 6 mg kg(-1)) and placebo conditions. During the first visit, participants performed an incremental cycling test to determine their 3MT resistance. After a familiarization trial, participants performed a CAF or PL trial according to a randomized crossover design. One hour after ingesting capsules, the participants performed the 3MT to estimate the end-test power (EP) and work done above EP (WEP). Blood samples for sodium (Na(+)), potassium (K(+)), pH, and lactate concentrations were drawn pretest, 1 h after ingestion, and posttest. RESULTS: Significant differences in WEP (CAF vs. PL, 13.4 ± 3.0 vs. 12.1 ± 2.7 kJ, P < 0.05) but not in EP (CAF vs. PL, 242 ± 37 vs. 244 ± 42 W, P > 0.05) were determined between the conditions. Compared with the PL condition, the CAF condition yielded significantly higher power outputs (60-150 s), a lower fatigue rate during the 3MT (CAF vs. PL, 0.024 ± 0.007 vs. 0.029 ± 0.006 s(-1), P < 0.05), a significantly higher lactate concentration after the 3MT, and significantly lower K(+) concentrations at 1 h after caffeine ingestion. There were no significant interaction effects for pH and Na(+) concentrations. CONCLUSIONS: Caffeine ingestion did not change EP but improved WEP and the rate of decline in power output during short-term, severe exercise.

A feasibility study of a predictive emissions monitoring system applied to taipower's nanpu and hsinta power plants.

The Hsinta and Nanpu Power Stations are located in southern Taiwan. The Hsinta Power Station consists of five combined-cycle gas turbines (CCGT), whereas the Nanpu Power Station consists of four. A project was undertaken to develop and deploy a predictive emissions monitoring system (PEMS) on CCGT unit 3 of Hsinta Power Station (HT-3) and CCGT unit 1 of Nanpu Power Station (NP-1) with the long-term goal of developing a universal model for this kind of power plant. After the first-year PEMS project at the Hsinta power plant, one goal of the second-year PEMS project was to set up a second PEMS at the Nanpu power plant and compare the PEM models applied the to two gas-fired combined cycle power generation units. Consequently, the second and third PEMS of Taiwan at CCGT HT-3 and NP-1 were finished. After comparing the differences among HT-1, HT-3, and NP-1 PEMS models, the pattern of model functionality indicated that this model could be applied to the other units of the same type and size. However, the PEMS function constant or parameter coefficients must be modified on a case-by-case basis. With regard to the PEMS model developed for HT-3, the relative accuracy (RA) of the 15-variable model with start-up mode is only 7.43% and met the criteria of draft PS-16. With regard to the PEMS model developed for NP-1, the RA of the 10-variable model with start-up mode was only 7.76% and also met the criteria of draft PS-16.