منابع مشابه
Significant improvement of optical traps by tuning standard water immersion objectives
Focused infrared lasers are widely used for micromanipulation and visualization of biological specimens. An inherent practical problem is that off-the-shelf commercial microscope objectives are designed for use with visible and not infrared wavelengths. Less aberration is introduced by water immersion objectives than by oil immersion ones, however, even water immersion objectives induce signifi...
متن کاملSympathoadrenal Response to Water Immersion.
M AN IN NORMAL gravity is primarily upright and an efficient system of reflex cardiovascular mechanisms have envolved which compensate for the hydrostatic pressure effects of body fluids due to gravity. When one stands erect most of the large arteries and veins are oriented parallel to the gravitational field and significant hydrostatic pressures are produced in these long columns of blood. 400...
متن کاملCardiovascular regulation during water immersion.
Head-out water immersion at thermoneutral temperature (34-35 degrees C) increases cardiac output for a given O2 consumption, leading to a relative hyperperfusion of peripheral tissues. To determine if subjects immersed in water at a colder temperature show similar responses and to explore the significance of the hyperperfusion, cardiovascular functions were investigated (impedance cardiography)...
متن کاملPsychobiologic effects of water-immersion-induced hypodynamics.
O F THE many biomedical problems that man will encounter in eventual space flight, prolonged weightlessness is the most difficult to evaluate. Having evolved in the normal gravitational field of the Earth, man will find that the muscular efforts, consciously or subconsciously needed in normal life, will be markedly reduced in a floating type of existence. That component of muscular tone previou...
متن کاملImmersion in water in labour and birth.
BACKGROUND Enthusiasts suggest that labouring in water and waterbirth increase maternal relaxation, reduce analgesia requirements and promote a midwifery model of care. Sceptics cite the possibility of neonatal water inhalation and maternal/neonatal infection. OBJECTIVES To assess the evidence from randomised controlled trials about immersion in water during labour and waterbirth on maternal,...
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ژورنال
عنوان ژورنال: Science
سال: 1922
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.55.1429.539-a