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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14

The effect of chronic erythrocytic polycythemia and high altitude upon plasma and blood volumes.

Comparison of two kinds of physiological chronic erythrocytic polycythemias in order to differentiate the specific effect of erythrocytic polycythemia from the general effects of high altitude upon the plasma volume. The two kinds were produced hormonally in female chickens, at sea level, or by protracted high-altitude exposures. It appears that the vascular system of the body may account for an increase in red blood cell mass either by reduction in plasma volume, or by no change in plasma volume, resulting in differential changes in total blood volumes.

Burton, R. R.↗

Indirect Blood Pressure Measuring Device

Design and performance of a blood pressure recording device for pediatric use are reported. A strain gage transducer with a copper-beryllium strip as force sensing element is used to monitor skin movements and to convert them into electrical signals proportional to those displacements. Experimental tests with this device in recording of force developed above the left femoral artery of a dog accurately produced a blood pressure curve.

Hum, L.↗

An implantable blood pressure and flow transmitter.

A miniature totally implantable FM/FM telemetry system has been developed to simultaneously measure blood pressure and blood flow, thus providing an appreciation of the hemodynamics of the circulation to the entire body or to a particular organ. Developed for work with animal subjects, the telemetry system's transmission time is controlled by an RF signal that permits an operating life of several months. Pressure is detected by a miniature intravascular transducer and flow is detected by an extravascular interferometric ultrasonic technique. Both pressure and flow are calibrated prior to implanting. The pressure calibration can be checked after the implanting by cannulation; flow calibration can be verified only at the end of the experiment by determining the voltage output from the implanted sensing system as a function of several measured flow rates. The utility of this device has been established by its use in investigating canine renal circulation during exercise, emotional encounters, administration of drugs, and application of accelerative forces.

Rader, R. D.↗

Repeated action of a constant magnetic field on the blood coagulation system in artificially produced anemia

Changes are discussed in the coagulatory system of the blood in rabbits under the influence of a constant magnetic field of an intensity of 2500 oersteds against the background of artificially induced anemia. Reversibility of the changes produced and the presence of the adaptational effect are noted. Taking all this into consideration, the changes involving the coagulatory system of the blood which arise under the influence of a constant magnetic field may be considered to have a nerve-reflex nature.

Zabrodina, L. V.↗

Effect of magnetic bracelets on the coagulation and anticoagulation systems of the blood of patients with hypertension

The data which have been obtained on the influence of magnetic bracelets on the coagulation and anticoagulation systems of the blood indicate that the wearing of magnetic bracelets results in a decrease in the coagulation activity of the blood and an increase in the activity of the anticoagulation system. These changes must be viewed as favorable for patients with cardiovascular pathology.

Bublis, V. V.↗

Blood electrolytes and exercise in relation to temperature regulation in man

Current knowledge and theories about the relation of blood electrolytes and exercise to thermoregulation in man are reviewed. It is shown that the elevation of body temperature during physical exercise is a regulated process and is not due to a failure of the heat dissipating mechanisms. Core and skin temperatures do not provide sufficient information to account for the control of sweating during exercise. Evidence is presented that suggests an association between equilibrium levels of rectal temperature and the osmotic concentration of the blood with essentially no influence of variations in plasma volume.

Greenleaf, J. E.↗

The determination of ethanol in blood and urine by mass fragmentography

A mass fragmentographic technique for a rapid, specific and sensitive determination of ethanol in blood and urine is described. A Varian gas chromatograph coupled through an all-glass membrane separator to a Finnigan quadripole mass spectrometer and interfaced to a computer system is used for ethanol determination in blood and urine samples. A procedure for plotting calibration curves for ethanol quantitation is also described. Quantitation is achieved by plotting the peak area ratios of undeuterated-to-deuterated ethanol fragment ions against the amount of ethanol added. Representative results obtained by this technique are included.

Pereira, W. E.↗

Portable automatic blood analyzer

Analyzer employs chemical-sensing electrodes for determination of blood, gas, and ion concentrations. It is rugged, easily serviced, and comparatively simple to operate. System can analyze up to eight parameters and can be modified to measure other blood constituents including nonionic species, such as urea, glucose, and oxygen.

Coleman, R. L.↗

Study of a number of biochemical indices of the blood and tissue of dogs after prolonged gamma-radiation

The glucose content in blood and the lipid content in serum and tissues of dogs exposed to chronic radiation for 3 and 5 years were studied. In tissues of these animals, the concentration of soluble DNA and DNA contained in DNP was studied in the spleen, lymph node (deep cervical node) and bone marrow of thigh bones. Results indicate that chronic gamma irradiation significantly changes concentrations of glucose in the blood, and that of several lipids in serum and tissues. A reduction in the concentration of DNP in tested organs reflects changes in the relative number of cells with various nuclear cytoplasmic ratios; most pronounced changes in biochemical indices occur in dogs exposed to chronic gamma radiation in doses of 125 rad per year.

Alers, I.↗

Blood circulation under weightless conditions

Biomedical data obtained on men and animals during weightlessness conditions establish instabilities in pulse rate and blood circulation that smooth out in proportion to adaptation to the weightless condition. The unusual slowness of recovery of pulse rate to initial values after space flight stress is attributed to biological simulation of hormonal shifts and discharge of humoral substances into the blood that prevent a rapid recovery of some biological indicators to initial values.

Kasyan, I. I.↗

Automatic blood pressure measuring system (M092)

The Blood Pressure Measuring System is described. It measures blood pressure by the noninvasive Korotkoff sound technique on a continual basis as physical stress is imposed during experiment M092, Lower Body Negative Pressure, and experiment M171, Metabolic Activity.

Nolte, R. W.↗

Variation of forearm, hand, and finger blood flow indices with ambient temperature

Forearm, hand, and finger blood flow (impedance) changes are measured by impedance rheography on seven healthy male subjects aged 20-35 yr during exposure to ambient temperatures ranging from 10 to 46 C. All observations are made in an environmental chamber at a dew point temperature of 13 + or - 0.25 C. It is shown that impedance rheography is suitable for quantifying peripheral circulatory responses to thermal stress. The measured blood flow indices are found to be consistent with previously reported values for the forearm, hand, and fingers obtained using air or water displacement plethysmography. In particular, the more distal body segments exhibit relatively larger vasomotor responses to changes in ambient temperature than do the more proximal body segments.

Montgomery, L. D.↗

A probe for blood-vessel and spinal interiors

Probe design allows insertion into lumen of blood vessels to perform oximetry and investigate plaque on interior vessel walls. Probe is more accurate than standard oximetry procedures of determining oxygenation of circulating blood.

Frazer, R. E.↗

In vivo blood-flow mapping

Application of laser doppler techniques to commercially available, low loss fiber optics allows direct reading of blood velocity within tiny blood vessels.

Frazer, R. E.↗

Spatial distribution of pulmonary blood flow in dogs in increased force environments

Spatial distribution of pulmonary blood flow during 2- to 3-min exposures to 6-8 Gy acceleration was studied, using radioactive microspheres in dogs, and compared to previously reported 1 Gy control distributions. Isotope distributions were measured by scintiscanning individual 1-cm-thick cross sections of excised, fixed lungs. Results indicate: (1) the fraction of cardiac output traversing left and right lungs did not change systematically with the duration and magnitude of acceleration; but (2) the fraction is strongly affected by the occurrence or absence of fast deep breaths, which cause an increase or decrease, respectively, in blood flow through the dependent lung; and (3) Gy acceleration caused a significant increase in relative pulmonary vascular resistance (PVR) in nondependent and dependent regions of the lung concurrent with a decrease in PVR in the midsagittal region of the thorax.

Greenleaf, J. F.↗

Effect of prolonged hypokinesia on tissue blood flow

The influence of hypokinesia on the blood flow in the tissues of rabbits was studied. Motor activity of animals was restricted during 90 days and blood flow recorded through resorption rate of NaI-131. Perfusion of tissues under the influence of hypokinesia was found to be reduced.

Levites, Z. P.↗