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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 1,459 records · Page 81
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Hypoxia, gas narcosis, and metabolic response to argon and nitrous oxide

Studies of the mechanism of inert gas influence on metabolism are reported. The studies reported include: metabolic response of hamsters to argon and nitrous oxide, membrane fatty acids and susceptability to narcotic gas influence, narcosis-induced histotoxic hypoxia, biochemical study of inert gas narcosis, hypoxia-induced protection against cardiovascular deterioration in the weightless state, and acute metabolic and physiologic response of goats to narcosis.

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NASA NTRS1973

Automated Microbial Metabolism Laboratory

Development of the automated microbial metabolism laboratory (AMML) concept is reported. The focus of effort of AMML was on the advanced labeled release experiment. Labeled substrates, inhibitors, and temperatures were investigated to establish a comparative biochemical profile. Profiles at three time intervals on soil and pure cultures of bacteria isolated from soil were prepared to establish a complete library. The development of a strategy for the return of a soil sample from Mars is also reported.

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NASA NTRS1973

Mechanisms of inert gas narcosis

Experiments describing the mechanism of inert gas narcosis are reported. A strain of mice, genetically altered to increase susceptibility to botulin poisoning (synaptic response) appears to increase metabolic rates while breathing argon; this infers a genetically altered synaptic response to both botulin toxin and narcotic gases. Studies of metabolic depression in human subjects breathing either air or a 30% mixture of nitrous oxide indicate that nitrous oxide narcosis does not produce pronounced metabolic depression. Tests on mice for relative susceptibilities to narcosis and oxygen poisoning as a function of fatty membrane composition show that alteration of the fatty acid composition of phospholipids increases resistance to metabolically depressant effects of argon but bas no effect on nitrous oxide narcosis. Another study suggests that acclimatization to low tension prior to high pressure oxygen treatment enhances susceptibility of mice to convulsions and death; developing biochemical lesions cause CNS metabolite reductions and pulmonary damage.

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NASA NTRS1972

Sleep deprivation and the organization of the behavioral states.

Questions concerning the significance of sleep in the developing organism are investigated, together with the mechanisms that underlie the unique distribution of behavioral states at any particular age and during any particular experimental manipulation. It is attempted to define the states of sleep and wakefulness in terms of a temporal confluence of a number of more or less independent processes, taking also into account the functional consequences of these attributes. The results of a selective deprivation of rapid eye movement sleep are explored, giving attention to effects on sleep, behavioral changes, brain excitability, pharmacological changes, and biochemical changes.

Dement, W. C.↗
NASA NTRS1972

Informational biopolymer structure in early living forms.

Some studies devoted to the search in various organisms for 'relics' of the biochemical nature of ancient organisms, preserved by the conservative nature of the evolutionary process in all living species, are reviewed. Investigations of five families of informational molecules constituting such 'relics' in very diverse organisms are reported. They include: cytochrome c, ferredoxin, trypsin, transfer ribonucleic acid (RNA), and 5S ribosomal RNA. It is shown that, even from these few informational molecules, some interesting inferences about early living organisms can be drawn.

Dayhoff, M. O.↗
NASA NTRS1971

Variable photosynthetic units, energy transfer and light-induced evolution of hydrogen in algae and bacteria.

The present state of knowledge regarding the truly photochemical reactions in photosynthesis is considered. Nine-tenths of the available knowledge is of a biochemical nature. Questions regarding the activities of the chlorophyll system are examined. The simplest photochemical response observed in living hydrogen-adapted algal cells is the release of molecular hydrogen, which continues even after all other known natural reactions have been eliminated either by heating or the action of poisons.

Gaffron, H.↗
NASA NTRS1973

Effect of lunar materials on plant tissue culture.

Lunar material collected during the Apollo 11, 12, 14, and 15 missions has been used to treat 12 species of higher plant tissue cultures. Biochemical and morphological studies have been conducted on several of these species. Tobacco tissue cultures treated with 0.22 g of lunar material exhibited increased greening more complex chloroplasts, less cytoplasmic vacuolation and greater vesiculation. Pine tissue cultures reacted to treatment by an increased deposition of tannin-like materials. The percentage of dry weight and soluble protein was increased in cultures treated with either lunar or terrestrial rock materials.

Walkinshaw, C. H.↗
NASA NTRS1972

Thin-film temperature sensor.

A new device has been developed for sensing small and rapid temperature changes accompanying biochemical reactions. The active element consists of an evaporated thin-film capacitor having a relatively strong temperature dependence. This dependence is derived from electron trapping effects in the thin amorphous dielectric film. A voltage output of at least 50 mV/deg can be obtained prior to amplification by using a resonant ac bridge circuit operating at 100 kHz. The corresponding noise output for a 10 kHz bandwidth can with an optimum circuit be as low as 4 microvolts. Therefore, the minimum detectable temperature change would be 80 microdegrees at 10 kHz. Rapid thermal response is assured by supporting the thin-film capacitor on a thin anodic tantalum oxide film suspended across an electrolytically etched window in a tantalum foil.

Maserjian, J.↗
NASA NTRS1974

Investigations in space-related molecular biology

Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

Fernandez-Moran, H.↗
NASA NTRS1974

Automated microbial metabolism laboratory

The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

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NASA NTRS1974

Feasibility study for the manufacture of zero gravity pharmaceuticles, immunological, and viral agents

The feasibility of extracting, isolating, purifying, separating, or preparing medical and biological products of high socio-economic value in space was studied. In particular, the study was designed to concentrate on the isolation or purification of virals, pharmaceutical and immunological agents by means of electrophoresis, as the Apollo 16 flight demonstrated that a mixed population of latex spheres (.2 and .8 microns) could be successfully separated by electrophoresis in space and without sedimentation with minimal convection. This prompted NASA scientists to look into the possibility of carrying out types of biochemical experiments that would utilize space for medical purposes.

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NASA NTRS1973

Laboratory techniques and rhythmometry

Some of the procedures used for the analysis of rhythms are illustrated, notably as these apply to current medical and biological practice. For a quantitative approach to medical and broader socio-ecologic goals, the chronobiologist gathers numerical objective reference standards for rhythmic biophysical, biochemical, and behavioral variables. These biological reference standards can be derived by specialized computer analyses of largely self-measured (until eventually automatically recorded) time series (autorhythmometry). Objective numerical values for individual and population parameters of reproductive cycles can be obtained concomitantly with characteristics of about-yearly (circannual), about-daily (circadian) and other rhythms.

Halberg, F.↗
NASA NTRS1973

Application of selected methods of remote sensing for detecting carbonaceous water pollution

A reach of the Houston Ship Channel was investigated during three separate overflights correlated with ground truth sampling on the Channel. Samples were analyzed for such conventional parameters as biochemical oxygen demand, chemical oxygen demand, total organic carbon, total inorganic carbon, turbidity, chlorophyll, pH, temperature, dissolved oxygen, and light penetration. Infrared analyses conducted on each sample included reflectance ATR analysis, carbon tetrachloride extraction of organics and subsequent scanning, and KBr evaporate analysis of CCl4 extract concentrate. Imagery which was correlated with field and laboratory data developed from ground truth sampling included that obtained from aerial KA62 hardware, RC-8 metric camera systems, and the RS-14 infrared scanner. The images were subjected to analysis by three film density gradient interpretation units. Data were then analyzed for correlations between imagery interpretation as derived from the three instruments and laboratory infrared signatures and other pertinent field and laboratory analyses.

Davis, E. M.↗
NASA NTRS1974

Cardiac mechanics: Physiological, clinical, and mathematical considerations

Recent studies concerning the basic physiological and biochemical principles underlying cardiac muscle contraction, methods for the assessment of cardiac function in the clinical situation, and mathematical approaches to cardiac mechanics are presented. Some of the topics covered include: cardiac ultrastructure and function in the normal and failing heart, myocardial energetics, clinical applications of angiocardiography, use of echocardiography for evaluating cardiac performance, systolic time intervals in the noninvasive assessment of left ventricular performance in man, evaluation of passive elastic stiffness for the left ventricle and isolated heart muscle, a conceptual model of myocardial infarction and cardiogenic shock, application of Huxley's sliding-filament theory to the mechanics of normal and hypertrophied cardiac muscle, and a rheological modeling of the intact left ventricle. Individual items are announced in this issue.

Mirsky, I.↗
NASA NTRS1972

Ocean color, a three component system?

This study measures the concentrations of phytoplankton chlorophyll and yellow substance in the coastal waters of the Gulf of Maine. Sea surface observations attempt to delineate the principal biochemical parameters responsible for sea surface color. It is shown that the reddish-brown water changed to a blue-green in the open gulf.

Yentsch, C. S.↗
NASA NTRS1974

Differential electrophoretic separation of cells and its effect on cell viability

An electrophoretic separation method was applied to the separation of cells. To determine the efficiency of the separation, it was necessary to apply existing methodology and develop new methods to assess the characteristics and functions of the separated subpopulations. Through appropriate application of the widely used isoelectric focusing procedure, a reproducible separation method was developed. Cells accumulated at defined pH and 70-80% remained viable. The cells were suitable for further biologic, biochemical and immunologic studies.

Leise, E. M.↗
NASA NTRS1975

Studies on possible propagation of microbial contamination in planetary atmospheres

Maintained aerosols were studied to demonstrate the metabolism and propagation of microbes in clouds which could occur in the course of a probe of a planetary atmosphere. Bacteriophage was used as a tool to test whether the mechanisms for DNA production remain intact and functional within the airborne bacterial cell. In one test method, bacteria were mixed with coliphage in an atomizer to allow attachment before aerosolization; in another, two suspensions were atomized saperately into a common air stream prior to aerosolization. Results show that biochemical and physiological mechanisms to allow aerobic microbes to propagate in the airborne state do exist.

Dimmick, R. L.↗