The mechanism by which psychological stress elicits various physiological responses is unknown. We discovered a central master neural pathway in rats that drives autonomic and behavioral stress responses by connecting the corticolimbic stress circuits to the hypothalamus. Psychosocial stress signals from emotion-related forebrain regions activated a VGLUT1-positive glutamatergic pathway from the dorsal peduncular cortex and dorsal tenia tecta (DP/DTT), an unexplored prefrontal cortical area, to the dorsomedial hypothalamus (DMH), a hypothalamic autonomic center. Genetic ablation and optogenetics revealed that the DP/DTT→DMH pathway drives thermogenic, hyperthermic, and cardiovascular sympathetic responses to psychosocial stress without contributing to basal homeostasis. This pathway also mediates avoidance behavior from psychosocial stressors. Given the variety of stress responses driven by the DP/DTT→DMH pathway, the DP/DTT can be a potential target for treating psychosomatic disorders.

The laser-induced exciplex fluorescence (LIEF) technique, which is based on spectrally resolved two-colour fluorescent emissions, has been applied to an evaporating diesel spray for the simultaneous separation of liquid and vapour phases on the two-dimensional images. The exciplex system is based on the TMPD/naphthalene system proposed by Melton. The temporal and spatial distribution of liquid and vapour phases during the mixture formation process was detected by this technique. In the LIEF technique, the vapour phase is detected by the monomer fluorescence while the liquid phase is tracked by the exciplex fluorescence. It is able to provide quantitative information on the diffusion state for applying the statistical entropy concept. This concept was put into practice in the image sets obtained through LIEF measurement in order to investigate the diffusion process of vapour phase in the evaporating diesel spray. The laser shadowgraph was taken to deduce the effect of turbulent mixing on the ignition. The experiments were conducted in a direct injection diesel engine with optical access required for the two-dimensional laser imaging. From the results, it is found that ignition occurs in the region where turbulent mixing has advanced a nearly homogeneous mixture of fuel vapour and air. Multi-sectional images obtained by LIEF indicate that there is a spatial dependence of ignition on the vapour-phase fuel in the combustion chamber.

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We aimed at the development of the powerfu1 ignition system (active ignition) that achieves highly effective combustion.In order to achieve the stabilization of the initial combustion, we had been studying the generation of active species mass, yolumetric ignitien and a long pulse duration discharge. In this study, we developed the ignition system without a large-scale structural change from a conventional engine. The active ignition system consists ofa primary coil (ignition coil) ofstandard spark discharge, and a secondary coil ofhigh frequency supply. Plasrna is generable by emphasizing sparks with high frequency voltage. By applying a high frequency voltage, the spark discharge can increase the speed and the number ofcollisions, Plasma and free radicals are produced by this phenomenon, In order to compare the effect ofigriition, the constant volume combustion chamber that can give a flow was used and took a high-speed video using Schlieren photography. In this study, we report that the improyement ofcombustion in the engine by using a new ignition system applied HF electric field.