RESUMEN
One of the main challenges in ultrafast material science is to trigger phase transitions with short pulses of light. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a coherent macroscopic transformation pathway for the semiconducting-to-metal transition in bistable Ti3O5 nanocrystals. Employing femtosecond powder X-ray diffraction, we measure the lattice deformation in the phase transition as a function of time. We monitor the early intra-cell distortion around the light absorbing metal dimer and the long range deformations governed by acoustic waves propagating from the laser-exposed Ti3O5 surface. We developed a simplified elastic model demonstrating that picosecond switching in nanocrystals happens concomitantly with the propagating acoustic wavefront, several decades faster than thermal processes governed by heat diffusion.
RESUMEN
Low-molecular volatile metabolites were studies in breath of healthy human subjects exposed to prolonged hypodynamia and verified as potential biomarkers of hypoxia in skeletal muscles and myocardiur by comparison with energy metabolism biochemical indices. cs) was explored Profile of volatile organic compounds (VOCs) was explored in breath of human subjects whose motor activities were limited due to 520-d isolation and connnemnerK nVIC - Analysis of detected voCs and comparison with dynamics of energy metabilism resulted in suggesting acetol as a potential breath biomarker of tissue hypoxia in skeletal muscles and myocardium. origination of acetol, the lactate precursor in methylglyoxal glucose oxidation, was hypothesized. It was shown that acetol decreases in consequence of low motor activity correlates with changes in biochemical indices of enzymes involved in energy metabolism and glycolysis, and also creatinine indicative of underloading the skeletal muscles. Decline in the activities of muscular and myocardial constellation enzymes during hypodynamia matches with the reliable dicrease in breath acetol.
