Relation between excessive CO2 expiration and performance in high-intensity exercise

This study examined the relation between excessive CO2 expiration and exercise performance in exercise exhausted for 1-2 min. First, the Wingate test was conducted to determine the exercise intensity of the performance test. The exercise intensity was set at 80% of the power exerted during the last 5 s of the Wingate test so that subjects could continue for 1-2 min. Total work, which was the value of the work rate times the performed duration was used as an index of the performance level. The excessive CO2 expiration rate (‡CO2excess) was defined as the difference between CO2 output and O2 uptake. Integration of ‡CO2excess from the start of exercise to the zero level of ‡CO2excess observed at around 10 min in recovery was defined as the amount of excessive CO2 expiration (CO2excess). The performance was associated with the peak value of blood lactate (peak La) obtained after exercise (r=0.744). The performance was also associated with CO2excess (r=0.848). It is likely that CO2excess is a better physiological index for assessing the performance in exercise exhausted for 1-2 min than peak La

Rectangular model of a ballistic spin interferometer in (001) InGaAs/InAlAs quantum wells

We report an unambiguous detection of the crytalline anisotropy of the spin-orbit interaction in (001) InAlAs/InGaAs/InAlAs quantum wells using nanofabricated rectangular loop arrays, where the sides of the constituent loops are aligned along either the [110] or [110￣] crystallographic axis. The fabrication and measurements were performed on the epi-wafer samples whose spin properties were characterized previously [Koga et al., Phys. Rev. Lett 89, 046801 (2002)]. We find that the experimentally observed spin interference patterns ― the amplitude modulation of the Al'tshuler-Aronov-Spivak oscillations as a function of the gate voltage ― are in good agreement with the results of the spin interferometer model extended for rectangular loops and including both the Rashba and Dresselhaus spin-orbit interactions

Recurrence of Left Ventricular Outflow Tract Obstruction Requiring Alcohol Septal Ablation after Transcatheter Aortic Valve Implantation

Left ventricular outflow tract (LVOT) obstruction is sometimes observed in patients with severe aortic stenosis (AS). It is still controversial how to manage the remaining severe AS, when LVOT obstruction is well-controlled by medical therapy. We report a case with acute recurrence of LVOT obstruction requiring emergent alcohol septal ablation (ASA) after transcatheter aortic valve implantation (TAVI), even in a stable state on beta-blockers. For the ASA procedure, transesophageal echocardiography was useful to clearly observe the perfusion area of the target septal branch by injecting microbubble contrast. Since it took some time to cause the recurrence of LVOT obstruction in this case, careful evaluation should be done after TAVI in high-risk patients for LVOT obstruction before terminating the TAVI procedure

Phase-Field Simulations and Analysis of Effect of Dispersed Particles on Migration of Delta to Gamma Transformation Interface

Retardation effect of dispersed inert particles on delta-gamma interface migration in carbon steels during isothermal delta to gamma transformation is analyzed by two-dimensional phase-field simulations. The effect is systematically investigated for different values of particle radius, r, particle spacing, l, and initial carbon concentration of delta phase. The retardation effect becomes stronger when the pinning parameter described by r/l (2) is larger and the carbon concentration of delta phase is higher, indicating that delta to gamma transformation kinetics can be retarded in a similar way to the pinning effect on grain growth kinetics