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 COMPARATIVE STUDIES ON RESPIRATION

1918 ◽  
Vol 1 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Carbon Dioxide ◽  
Aquatic Insects ◽  
Aquatic Insect ◽  
Co2 Production ◽  
Body Movements ◽  
Carbon Dioxide Output ◽  
Co2 Output ◽  
Frog Tadpoles ◽  
Temporary Decrease ◽  
Narcotic Action

1. The experiments on frog tadpoles show that with 0.15, 0.37, and 0.55 per cent ether solutions there is a decrease in CO2 output. The effect is reversible. With these concentrations the breathing movements and body movements remained normal during the experiment. In 3.65 and 7.3 per cent ether there is a decrease of respiration followed by an increase which in turn is followed by a decrease. The increase may reach about three times the normal rate. The increase in the CO2 output is accompanied by the peeling of the skin. The effect is irreversible. 2. Experiments on an aquatic insect, Dineutes assimilis Aube, show that in 7.3 per cent ether there is a decrease followed by an increase which in turn is followed by a decrease. There is no apparent disintegration of structures in the organism accompanying the increase. The effect is irreversible. 3. The experiments on frog eggs with 7.3 per cent ether show a result similar to that found in aquatic insects. 4. Experiments on Fundulus embryos show that with 0.73 per cent ether there is a reversible decrease in the rate of CO2 production. In 3.65 per cent ether there is a temporary decrease followed by an increase, after which the rate begins to fall off. In 7.3 per cent ether there is an immediate increase amounting to 307 per cent which is followed by a decrease. The increase in the 3.65 and 7.3 per cent ether is accompanied by irreversible changes leading to death. The decrease found in 0.73 per cent ether is not sufficient to cause narcosis, as is shown by experiments on which the same decrease is produced by lowering the temperature. 5. These experiments show that narcosis is not due to asphyxia. The action of anesthetics is due to some other cause than the effect on respiration. There is a difference between the animals studied and the plants described in this series of articles, since in animals the increase in the CO2 output is accompanied by irreversible changes leading to death, while this is not necessarily the case in plants. The reversible (narcotic) action of ether on the animals studied was accompanied by a decrease in the carbon dioxide output; in plants this is not ordinarily the case. These facts are of considerable interest, but their interpretation must be left to future investigation.

scholarly journals Effect of Anoxia on Respiration Rate (Fermentative Index) and Ethanol Production of Onion Bulbs (Allium cepa L.)

2003 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
N. Benkeblia ◽  
N. Shiomi
Keyword(s):  
Carbon Dioxide ◽  
Ethanol Production ◽  
Respiration Rate ◽  
Allium Cepa ◽  
Average Rate ◽  
Carbon Dioxide Production ◽  
Co2 Production ◽  
Temperature Dependent ◽  
Onion Bulbs ◽  
Allium Cepa L

The physiological behavior, including carbon dioxide production, fermentative index (FI) and ethanolic production of onion bulbs kept under total anoxia (l00% N2) was investigated. During the first 24 hours, carbon dioxide production increased from 0.01 to 1.56 kPa Co2, and the average rate of the increase in CO2; production between 0 and 24 hours was 0.09 kPa/h. The Q10, of the fermentative index was l.9. Ethanol produced by onion bulbs kept under anoxia during 6 hours was temperature dependent, and was 0.563 and 0.760 pmol kg-1h-1 at 10 and 20°C respectively, while at 4°C the quantity produced was not detected. It is concluded that onion seems to be less tolerant to anoxia than other vegetables such as artichoke, cauliflower, tomato, potato and asparagus.  

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

scholarly journals Thermodynamic Study of Energy Consumption and Carbon Dioxide Emission in Ironmaking Process of the Reduction of Iron Oxides by Carbon

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1999
Author(s):  
Guanyong Sun ◽  
Bin Li ◽  
Hanjie Guo ◽  
Wensheng Yang ◽  
Shaoying Li ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Iron Oxides ◽  
Volume Fraction ◽  
Minimum Energy ◽  
Carbon Dioxide Emission ◽  
Reduction Reactions ◽  
Co2 Output ◽  
Coupling Parameters ◽  
Ironmaking Process

Carbon included in coke and coal was used as a reduction agent and fuel in blast furnace (BF) ironmaking processes, which released large quantities of carbon dioxide (CO2). Minimizing the carbon consumption and CO2 output has always the goal of ironmaking research. In this paper, the reduction reactions of iron oxides by carbon, the gasification reaction of carbon by CO2, and the coupling reactions were studied by thermodynamic functions, which were derived from isobaric specific heat capacity. The reaction enthalpy at 298 K could not represent the heat value at the other reaction temperature, so the certain temperature should be confirmed by Gibbs frees energy and gas partial pressure. Based on Hess’ law, the energy consumption of the ironmaking process by carbon was calculated in detail. The decrease in the reduction temperature of solid metal iron has been beneficial in reducing the sensible heat required. When the volume ratio of CO to CO2 in the top gas of the furnace was given as 1.1–1.5, the coupling parameters of carbon gasification were 1.06–1.28 for Fe2O3, 0.71–0.85 for Fe3O4, 0.35–0.43 for FeO, respectively. With the increase in the coupling parameters, the volume fraction of CO2 decreased, and energy consumption and CO2 output increased. The minimum energy consumption and CO2 output of liquid iron production were in the reduction reactions with only CO2 generated, which were 9.952 GJ/t and 1265.854 kg/t from Fe2O3, 9.761 GJ/t and 1226.799 kg/t from Fe3O4, 9.007 GJ/t and 1107.368 kg/t from FeO, respectively. Compared with the current energy consumption of 11.65 GJ/t hot metal (HM) and CO2 output of 1650 kg/tHM of BF, the energy consumption and CO2 of ironmaking by carbon could reach lower levels by decreasing the coupled gasification reactions, lowering the temperature needed to generate solid Fe and adjusting the iron oxides to improve the iron content in the raw material. This article provides a simplified calculation method to understand the limit of energy consumption and CO2 output of ironmaking by carbon reduction iron oxides.

Prevention of painful neuromas by oblique transection of peripheral nerves

2006 ◽  
Vol 104 (2) ◽  
pp. 285-289 ◽  
Author(s):  
Wieslaw Marcol ◽  
Katarzyna Kotulska ◽  
Magdalena Larysz-Brysz ◽  
Grazyna Bierzyñska-Macyszyn ◽  
Pawel Wlaszczuk ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Sciatic Nerve ◽  
Peripheral Nerves ◽  
Traditional Method ◽  
Healing Process ◽  
Nerve Transection ◽  
Proximal Stump ◽  
Sciatic Nerves ◽  
Neuroma Formation

Object Neuroma formation often occurs at the proximal stump of the transected nerve, complicating the healing process after gap injuries or nerve biopsies. Most such neuromas cause therapy-resistant neuropathic pain. The purpose of this study was to determine whether oblique transection of the proximal stump of the sciatic nerve can prevent neuroma formation. Methods The sciatic nerves of 10 rats were transected unilaterally at an angle of 30°, and the peripheral segments of the nerves were removed. In 10 control animals the sciatic nerves were transected at a perpendicular angle. Twenty weeks after surgery the nerves were reexposed and collected. The presence of neuromas was determined by two board-certified pathologists on the basis of histopathological evaluations. Conclusions The oblique transection of peripheral nerves, contrary to perpendicularly transected nerves, is rarely followed by classic neuroma development. Moreover, neuropathic pain is significantly reduced compared with that following the traditional method of nerve transection.

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.

scholarly journals The dynamic changes of main cell types in the microenvironment of sciatic nerves following sciatic nerve injury and the influence of let-7 on their distribution

RSC Advances ◽  
2018 ◽  
Vol 8 (72) ◽  
pp. 41181-41191 ◽  
Author(s):  
Tianmei Qian ◽  
Pan Wang ◽  
Qianqian Chen ◽  
Sheng Yi ◽  
Qianyan Liu ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Cell Types ◽  
Sciatic Nerve Injury ◽  
Dynamic Changes ◽  
Main Cell ◽  
Sciatic Nerves

Schwann cells (SCs), fibroblasts and macrophages are the main cells in the peripheral nerve stumps.

scholarly journals CARBON DIOXIDE FROM THE NERVE CORD OF THE LOBSTER

1925 ◽  
Vol 7 (6) ◽  
pp. 671-677 ◽  
Author(s):  
G. H. Parker
Keyword(s):  
Carbon Dioxide ◽  
Lateral Line ◽  
Nerve Cord ◽  
Homarus Americanus ◽  
Lateral Line Nerve ◽  
Steady Decrease ◽  
Co2 Output ◽  
Living Preparation

1. The nerve cord of the lobster (Homarus americanus Milne-Edwards) is very delicate and can be used as a living preparation for only a few hours after its removal from the animal. 2. During the first hour or so after removal it discharges CO2 at a steadily decreasing rate beginning at about 0.20 mg. CO2 per gram of cord per minute and ending at about 0.07 mg. 3. This discharge exhibits a steady decrease in rate and is not divisible into a period of gush and a period of uniform outflow as with the lateral-line nerve of the dogfish. It terminates in a very few hours with the complete death of the cord. 4. Both handling and cutting the cord temporarily increase the rate of CO2 output. 5. The stimulated cord discharges CO2 at a rate about 26 per cent higher than that of the quiescent cord, an increase of about 1.6 times that of the increase observed in the lateral-line nerve of the dogfish under similar circumstances.

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