Stress : Medical aspects

Hans selye (1907-1981) introduced the concept of ""stress"" into medical science (1936) and scince then it has been used in the physical sciences. There are many types stress; biological, physiological, physic-chemical aspects. Recently, there has been warning in an increase of mental stress. In case of a high score of type A , there is a high ratio of coronary heart disease. In addition, gastric ulcer and immunue dysfunction may be caused by mental stress. In the body, stress protein such as HSP 70 play an important role in repairing and assembling protein structures and in the catalyze and inhibition for degeneration of proteins. Prediction and preparation for stress may contribute to prevention of PTSD

Movement skill and its disorder

The control of motor skill consist of three systems : reflexive, autonomic and voluntary. Walking movement has an automatic motor function performed by three main control systems in brain stem. Voluntary movement is baused by the pathway from the cerebral cortex (motor area) to the spinal cord (anterior gray horn) inputting the motor neuron cell body which is the final common path to the muscle. The motor area is governed by the cerebelum and basal ganglia. Its output is controlled by feed back systems from the sensory area. Acetylcholine (neuro-muscular junction), Ca^(endoplasmic retriculum) and ATP (hydrolysis by ATPase) play an important role as chemical mediaters for muscle contraction. The dysfunction of each in any level of the motor control system causes motor disorder such as motor neuron disease, myasthenia gravis (acethylcholine receptor), progressive muscular dystrophy and Parkinson\u27s disease (dopamine neuron in basal ganglia)

Regulation of dendritic spine morphology by an NMDA receptor-associated Rho GTPase-activating protein, p250GAP

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66364/1/j.1471-4159.2008.05335.x.pd

Acclimation for environment

In heat environments, when adaptation to ""heat-stress"" is not yet formed, it leads to an increase in ratio of death owing to heart failier (5O% rising for average). The body adapts to heat stress by heart beating. An information of ""heat-stress"" is recieved by antero-hypothalamus (warmth neuron) via changes of brain blood flow and/or sense nerve from peripheral thermoreceptors. Then, vasodialation, enhanced heart rate and sweat secretion are caused by negative feedback regulation via autonomic nerve system. Continuously, check and integration of temperature through the hypothalamus are conducted by information from cutaneous, deep and visceral sensation. The exercise under the heat environment causes increase in heart-stroke, by rising muscle and brain temperature. After heat adaptation, Ald, ADH, plasma volume, stroke volume, venous return and sweat secretion increase. On the other hand, heart-rate and core temperature decrease. Cold stimulation, expresses shivering, pilomotor response and vasoconstraction at the first stage. After adapting cold environment, there is a chronical increase level of noradrenaline : regulatory nonshivering thermogenesis. Biological clock exists in the SCN which depend on light stimulation. SCN function play an important role for the control of functional biological rhythms

Production of an Amorphous Fe_<75>Si_<10>B_<15> Sheet by a Metallic Mold Casting Method and its Properties

The application of a metallic mold casting method to an Fe_Si_B_ alloy with the largest glass-forming ability in (Fe, Co, Ni)-Si-B system was found to cause the formation of a mostly single amorphous phase in a sheet form with a thickness of 0.1 mm. No distinct difference in thermal stability (crystallization temperature and heat of crystallization), hardness, Curie temperature and magnetization is detected between the as-cast sheet and the melt-spun amorphous ribbon with a thickness of 0.02 mm. On the other hand, bending ductility, heat of relaxation (ΔH_r) and coercivity (H_c) which can be regarded as structure sensitive properties are significantly different from those for the amorphous ribbon. That is, the sheet sample fractures during bending deformation and has a smaller ΔH_r and a larger H_c. The difference is induced presumably because the sheet sample has a more relaxed atomic configuration on a short-range scale as compared with that for the amorphous ribbon sample