scholarly journals DYNAMICS OF NERVE CELLS

1920 ◽  
Vol 3 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Walter E. Garrey
Keyword(s):  
Carbon Dioxide ◽  
Chemical Reaction ◽  
Cardiac Rhythm ◽  
Colorimetric Method ◽  
Heart Beat ◽  
Nerve Cells ◽  
Co2 Production ◽  
Cardiac Ganglion ◽  
Different Temperatures

1. It is possible to determine by the colorimetric method the rate of production of carbon dioxide by the cardiac ganglion of Limulus. 2. Carbon dioxide formation in the cardiac ganglion was found to run parallel to the rate of heart beat for different temperatures. 3. The conclusion seems justified that the rate of cardiac rhythm of Limulus depends upon a chemical reaction in the nerve cells of the cardiac ganglion and that this reaction is associated with the production of carbon dioxide since the rate of beat and the rate of CO2 production are similarly affected by changes in temperature.

scholarly journals The Effect of the Temperature and Moisture to the Permeation Properties of PEO-Based Membranes for Carbon-Dioxide Separation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2053
Author(s):  
Dragutin Nedeljkovic
Keyword(s):  
Carbon Dioxide ◽  
Partial Pressure ◽  
Carbon Dioxide Emission ◽  
Combustion Products ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix Membrane ◽  
Mixed Matrix ◽  
Gas Treatment ◽  
Carbon Dioxide Separation ◽  
Different Temperatures

An increased demand for energy in recent decades has caused an increase in the emissions of combustion products, among which carbon-dioxide is the most harmful. As carbon-dioxide induces negative environmental effects, like global warming and the greenhouse effect, a decrease of the carbon-dioxide emission has emerged as one of the most urgent tasks in engineering. In this work, the possibility for the application of the polymer-based, dense, mixed matrix membranes for flue gas treatment was tested. The task was to test a potential decrease in the permeability and selectivity of a mixed-matrix membrane in the presence of moisture and at elevated temperature. Membranes are based on two different poly(ethylene oxide)-based polymers filled with two different zeolite powders (ITR and IWS). An additive of detergent type was added to improve the contact properties between the zeolite and polymer matrix. The measurements were performed at three different temperatures (30, 60, and 90 °C) under wet conditions, with partial pressure of the water equal to the vapor pressure of the water at the given temperature. The permeability of carbon-dioxide, hydrogen, nitrogen, and oxygen was measured, and the selectivity of the carbon-dioxide versus other gases was determined. Obtained results have shown that an increase of temperature and partial pressure of the vapor slightly increase both the selectivity and permeability of the synthesized membranes. It was also shown that the addition of the zeolite powder increases the permeability of carbon-dioxide while maintaining the selectivity, compared to hydrogen, oxygen, and nitrogen.

Carbon Dioxide as a Factor in Heart Beat

Science ◽  
1909 ◽  
Vol 30 (774) ◽  
pp. 603-604
Author(s):  
Hugh McGuigan ◽  
R. H. Nicholl
Keyword(s):  
Carbon Dioxide ◽  
Heart Beat

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

Neurotransmission in neonatal rat cardiac ganglion in situ

1990 ◽  
Vol 259 (4) ◽  
pp. H997-H1005 ◽  
Author(s):  
G. R. Seabrook ◽  
L. A. Fieber ◽  
D. J. Adams
Keyword(s):  
Neuronal Cell ◽  
Nerve Fibers ◽  
Heart Beat ◽  
Neonatal Rat ◽  
Neuronal Cell Body ◽  
High Frequency Stimulation ◽  
Excitatory Postsynaptic Potential ◽  
Cardiac Ganglion ◽  
Cardiac Ganglia

The intrinsic cardiac ganglia of the neonatal rat heart in situ were studied using electrophysiological and histochemical techniques. The vagal branches innervating the atrial myocardium and cardiac ganglia were identified and individual ganglion cells visualized using Hoffman modulation contrast optics. Histochemical studies revealed the presence of acetylcholinesterase activity associated with neuronal cell bodies and fibers, catecholamine-containing, small intensely fluorescent cells, and cell bodies and nerve fibers immunoreactive for vasoactive intestinal polypeptide. Intracellular recordings from the "principal" cells of the rat cardiac ganglion in situ revealed a fast excitatory postsynaptic potential (EPSP) evoked after electrical stimulation of the vagus nerve, which was inhibited by the nicotinic receptor antagonist, mecamylamine. No spontaneously firing neurons were found, although infrequent (less than 2 min-1) spontaneous miniature EPSPs were observed in most neurons. The quantal content of neurally evoked responses was between 10 and 30 quanta, and the presence of multiple EPSPs in some cells suggested polyneuronal innervation. The neurally evoked EPSP amplitude was dependent on the rate of nerve stimulation, decreasing with increasing frequency of stimulation. Neurons exhibited a sustained depolarization during high frequency stimulation (greater than 1 Hz), and in approximately 15% of the cells a slow depolarization lasting 1-3 min was observed after a train of stimuli. The presence of catecholamine- and neuropeptide-containing neuronal cell body fibers in neonatal rat cardiac ganglia in situ, along with neurally evoked postsynaptic responses resistant to cholinergic ganglionic blockers, suggests a role for noncholinergic transmission in the regulation of the mammalian heart beat.

scholarly journals Determination of Oleanolic and Ursolic Acids inHedyotis diffusaUsing Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-Chi Wei ◽  
Yu-Chiao Yang ◽  
Show-Jen Hong
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Performance ◽  
Extraction Yield ◽  
Extraction Time ◽  
Different Temperatures ◽  
Ultrasound Assisted ◽  
High Concentrations ◽  
Static Extraction ◽  
Supercritical Carbon

Oleanolic acid (OA) and ursolic acid (UA) were extracted fromHedyotis diffusausing a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC–CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC–CO2flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant) and UA (3.540 mg/g of dry plant) were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v) cosolvent (ethanol/water = 82/18, v/v) and SC–CO2flowing at 2.3 mL/min (STP). The extracted yields were then analyzed by high performance liquid chromatography (HPLC) to quantify the OA and UA. The present findings revealed thatH. diffusais a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA fromH. diffusaat high concentrations.

scholarly journals THE EXCRETION OF CARBON DIOXIDE BY FROG NERVE

1925 ◽  
Vol 8 (2) ◽  
pp. 21-31 ◽  
Author(s):  
G. H. Parker
Keyword(s):  
Carbon Dioxide ◽  
Sciatic Nerve ◽  
Connective Tissue ◽  
Nervous Tissue ◽  
Average Rate ◽  
Boiling Water ◽  
Co2 Production ◽  
Co2 Output ◽  
Sciatic Nerves ◽  
Low Rate

1. Quiescent sciatic nerve of the frog discharges CO2 at the average rate of 0.00876 mg. CO2 per gram of nerve per minute. 2. Sciatic nerve steeped one minute in boiling water discharges CO2 at first at a low rate and after an hour and a half not at all. 3. Degenerated sciatic nerve discharges CO2 at a slightly higher rate than normal living nerve does. 4. Connective tissue from the frog discharges CO2 at an average rate of 0.0097 mg. per gram of tissue per minute. 5. Assuming that a nerve is composed of from one-half to one-quarter connective tissue the CO2 output from its strictly nervous components is estimated to be at a rate of 0.008 mg. CO2 per gram of nerve per minute. 6. Stimulated sciatic nerve increases the rate of its CO2 output over quiescent nerve by about 14 per cent. When this number is corrected for strictly nervous tissue the rate is about 16 per cent. 7. The increased rate of CO2 production noted on stimulation in normal sciatic nerves was not observed when they were boiled, blocked, or degenerated. It was also not observed with stimulated strands of connective tissue.

scholarly journals Quality and shelf life of packaged fresh sliced mushrooms stored at two different temperatures

2008 ◽  
Vol 15 (4) ◽  
pp. 414 ◽  
Author(s):  
E. GONZÁLEZ-FANDOS ◽  
A. SIMON JIMENES ◽  
V. TOBAR PARDO
Keyword(s):  
Carbon Dioxide ◽  
Shelf Life ◽  
Agaricus Bisporus ◽  
Microbiological Quality ◽  
Air Atmosphere ◽  
Pvc Film ◽  
Different Temperatures ◽  
Aerobic And Anaerobic ◽  
Quality And Shelf Life

The sensory and microbiological quality of sliced mushrooms (Agaricus bisporus L.) packaged in films of perforated and non-perforated PVC and stored at 3 and 9ºC, was studied. The carbon dioxide and oxygen content inside the packages, colour, weight loss, sensory attributes, mesophiles, Pseudomonas, Enterobacteriaceae, aerobic and anaerobic spore formers were determined. The atmosphere generated with the perforated PVC film was similar to that of air atmosphere at 3 or 9ºC. T.he non-perforated PVC film generated inside the packages CO2 : O2 concentrations of 3.4% : 8.1% at 3ºC and CO2 : O2 concentrations of 4.5% : 0.15% at 9ºC. Browning of mushrooms was lower at 3 than at 9ºC. The quality of sliced mushrooms packaged in perforated PVC and stored at 3ºC was adequate after 9 days. However, at 9ºC, the slice deformation and brown blotches incidence were severe after 9 days. The atmosphere generated with non-perforated PVC inhibited aerobic microorganism growth compared to mushrooms packaged in perforated PVC. At 3ºC, the shelf life of mushrooms packaged in non perforated PVC was around 13 days. However, the extremely low O2 atmospheres generated at 9ºC was accompanied by off-odours and growth of anaerobic spore formers, although the appearance of sliced mushrooms was acceptable.;

Chloral Hydrate and the Carbon Dioxide Chemoreceptor Response: A Study of Puppies and Infants

PEDIATRICS ◽  
1982 ◽  
Vol 70 (3) ◽  
pp. 447-450
Author(s):  
Martin H. Lees ◽  
George D. Olsen ◽  
Kip L. McGilliard ◽  
James D. Newcomb ◽  
Cecille O. Sunderland
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Eye Movement ◽  
Chloral Hydrate ◽  
Nrem Sleep ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rapid Eye Movement ◽  
Natural Sleep ◽  
Co2 Elimination

CO2 chemoreceptor function was assessed during natural sleep and following the administration of 100 mg/kg of chloral hydrate to 26 puppies. With chloral hydrate-induced sleep, there were no significant changes in ventilation or in CO2 chemoreceptor response. The ventilation and CO2 chemoreceptor response of a group of infants in natural sleep were compared with those of a group receiving 50 mg/kg of chloral hydrate. Tidal volume, O2 consumption, and CO2 elimination were slightly higher in the group given chloral hydrate. There was no difference in the CO2 chemoreceptor response. The proportion of time spent in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep in chloral hydrate-induced sleep was similar to that occurring in natural sleep. Use of chloral hydrate stabilizes O2 consumption and CO2 production, and it greatly facilitates the assessment of chemoreceptor function in infants. The CO2 chemoreceptor response appears not to be altered in puppies or infants.

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