scholarly journals ELECTROENDOSMOSIS THROUGH MAMMALIAN SEROUS MEMBRANES

1925 ◽  
Vol 7 (3) ◽  
pp. 389-413 ◽  
Author(s):  
Stuart Mudd
Keyword(s):  
Ph Value ◽  
Ion Concentration ◽  
Time Interval ◽  
Fat Cells ◽  
Post Mortem ◽  
Small Shift ◽  
Hydrogen Ion Concentration ◽  
Mean Values ◽  
Reversal Point ◽  
The Mean

It is shown that when a mammalian serous membrane bathed in dilute buffer is traversed by an electric current, liquid is caused to stream through the membrane toward the cathode when the pH value of the buffer is on the alkaline side of a certain critical hydrogen ion concentration. Streaming is toward the anode on the acid side of the reversal point. Simple means for studying this electroendosmosis quantitatively are described. The mean values of the reversal points in all cases studied with the present buffers lie between pH = 4.3 and 5.3. The membranes studied have been the mesentery of the living and dead animal, and the parietal pericardium and pleura, post mortem. The membranes of dogs, cats, rabbits, and two human pericardia have been studied. All these membranes are essentially sheets of connective tissue, bearing blood vessels, lymphatics, and nerves, and in some instances fat cells, and lined on each surface by a single layer of pavement mesothelial cells. Intercellular fibers form the major bulk of the lean membranes. These are predominantly collagenous except in the pleural region used, in which elastin fibers are present in large proportion. By using buffers alternately more acid or more alkaline than the reversal point, the direction of liquid flow across any given membrane site could be reversed an indefinite number of times. The time interval required is only that taken by the requisite manipulation in changing buffers and making the runs. The mean values of the reversal points for the several membranes when bathed in hypotonic, unbalanced buffer and in isotonic, physiologically balanced buffers showed only small and inconstant differences. The fat and lean pericardia similarly showed small difference in the positions of the mean reversal points. The apparent reversal points for the mesenteries of living animals proved to be lower than those for the mesenteries post mortem. This low value in the animals with functioning circulation is interpreted as essentially due to admixture with the buffers of buffer salts from the blood. Clear differences between the reversal points of the membranes in the first compared with later hours or days post mortem were not detected, with the possible exception of a small shift toward the acid range of the fat pericardium reversal points estimated several days post mortem. The reversal points with cat membranes were somewhat lower (more acid) than those of the dog. The approximate mean reversal points found with the citrate-phosphate buffers used were as follows: For mesenteries of living animals pH = 4.4; for mesenteries, post mortem, pH = 4.8; for cat pleuræ, post mortem, pH = 4.3; for dog pleuræ, post mortem, pH = 5.0; for lean and fat pericardia, post mortem, pH = 5.1. The mean reversal point of the two human pericardia was about pH = 5.0. Reversal points determined with buffers containing only monovalent anions are somewhat higher (less acid), as will be shown later. The bearing of these data on the question of the chemical composition of the surfaces of the fat cells of the serous membranes is discussed. Briefly, it is believed that proteins are probably present in important amount in these cell surfaces.

The hydrogen-ion concentration of the semen of the bull

1942 ◽  
Vol 32 (3) ◽  
pp. 298-307 ◽  
Author(s):  
J. Anderson
Keyword(s):  
Adverse Effect ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Clinically Normal ◽  
The Mean

1. The mean pH of 221 ejaculates of clinically normal bulls was 6·73 ± 0·020. Significant differences were noted between different bulls.2. There were highly significant negative correlations between the pH. of the ejaculates and the concentration of spermatozoa, the volume of ejaculate and the motility of the spermatozoa.3. The more acid the semen was on collection, the better was the motility retained on storage. Semen which retained its motility well became increasingly acid during storage. A change in the pH in the alkaline direction during storage had an adverse effect on motility. The more acid the pH on collection the less likely was a decrease in acidity during storage.

scholarly journals Response and Deterioration Mechanism of Bitumen under Acid Rain Erosion

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4911
Author(s):  
Xuemei Zhang ◽  
Inge Hoff ◽  
Rabbira Garba Saba
Keyword(s):  
Acid Rain ◽  
Ph Value ◽  
Negative Impact ◽  
Ion Concentration ◽  
Asphalt Pavements ◽  
Acid Oxidation ◽  
Hydrogen Ion Concentration ◽  
Deterioration Mechanism ◽  
Physical Tests ◽  
Rain Erosion

Acid rain as an important environmental issue has a negative impact on bitumen performance, thereby shortening the service life of asphalt pavements. Thus, this research aims to investigate the response of bitumen to acid rain and its deterioration mechanism. For this purpose, the simulated acid rain was prepared to erode neat bitumen and short-term aged bitumen. The hydrogen ion concentration of the acid rain, and the morphological, physical, chemical, and rheological properties of the bitumen were evaluated by means of a pH meter, scanning electron microscopy, physical tests, Fourier transform infrared radiation with attenuated total reflectance, and dynamic shear rheometer. The results showed that bitumen properties were severely affected by acid rain, and the changes in bitumen properties were highly related to the erosion time, leading to a reduction in pH value by 0.2 of residual acid rain, rougher bitumen surface, and stiffer bitumen with more oxygen-containing functional groups and fewer carbonyl acid groups (around 10% decrement) after 90 days erosion. These changes contributed to two deterioration mechanisms: oxidation and dissolution of carbonyl acid. Oxidation and dissolution are, respectively, the dominant actions for neat bitumen and aged bitumen during the erosion process, which eventually leads to various responses to acid rain.

scholarly journals Changes in selected physicochemical parameters of breast muscles of geese from Polish conservation flocks depending on duration of the post slaughter period

2008 ◽  
Vol 51 (3) ◽  
pp. 255-265 ◽  
Author(s):  
A. Okruszek ◽  
J. Książkiewicz ◽  
J. Wołoszyn ◽  
G. Haraf ◽  
A. Orkusz ◽  
...  
Keyword(s):  
Genetic Resources ◽  
Physicochemical Parameters ◽  
Ph Value ◽  
The Other ◽  
Mean Values ◽  
Qualitative Traits ◽  
Ph Values ◽  
Colour Parameters ◽  
The Mean

Abstract. In four Polish conservative flocks of Suwałki (Su), Kartuzy (Ka), Kielce (Ki) and Subcarpathian (Sb) geese, registered by FAO as domestic genetic resources the mean values of qualitative traits of breast muscles (pH15', pH30', pH45', pH24h; colour parameters: L*15', L*30', L*45', L24h, a*15', a*30', a*45', a*24h, b*15', b*30', b*45', b*24h and conductivity: EC45', EC3h, EC24h) were determined. The experimental flocks showed significant variations in the investigated parameters. The Kartuzy goose breast muscles were characterized by higher values of pH15' (6.74), pH30' (6.62), pH45' (6.56) and b*15' parameter (0.80) in comparison with the remaining flocks. Moreover, these muscles had the lowest pH24h (5.65) and values of L* parameter (L*15', L*30', L*45' and L*24h) and EC45' (3.23 mS/cm). The pH value and L* and a* parameters (except L*24h and a*24h) of the analysed flocks were decreasing, and conductivity increasing together with the time post slaughter, and the rate of changes depended on the birds’ origin. Greater differences between pH values, measured 15 min and 24 h after slaughter were stated in breast muscles from Ka (1.09) and Su (0.90) geese than from the other two flocks investigated (Ki – 0.74; Sb – 0.58). The highest increase in conductivity (from EC45' to EC24h) was affirmed in Ka and Ki muscles (3.84 mS/cm) and the lowest in breast muscles of Sb geese (2.72 mS/cm).

Chemical Constituents of Biological Importance in the English Channel. Part III. June-December, 1932. Phosphate, Silicate, Nitrate, Hydrogen Ion Concentration, with a Comparison with Wind Records

1933 ◽  
Vol 19 (1) ◽  
pp. 55-62 ◽  
Author(s):  
L. H. N. Cooper
Keyword(s):  
Chemical Constituents ◽  
Ion Concentration ◽  
English Channel ◽  
Hydrogen Ion Concentration ◽  
Unusual Distribution ◽  
Phosphate Silicate ◽  
Sunny Weather ◽  
Inshore Waters ◽  
The Mean ◽  
Practical Measure

In August, 1932, marked stratification of the water in the English Channel led to an unusual distribution of minor chemical constituents. Two thermoclines were present, between which high silicate values were found, indicating rapid re-solution of silica as found in former summers; pH was also very high at 15 metres.In or about December in four years, nitrite in inshore waters has been found much in excess of that present in the open Channel.The “mean cube Beaufort number” is suggested as a useful practical measure of sea disturbance. Three out of four midwinter plankton outbursts, inferred from a fall in the phosphate content of the water, have followed periods of sunny weather with little wind.

scholarly journals THE EFFECT OF THE H ION CONCENTRATION ON THE AVAILABILITY OF IRON FOR CHLORELLA SP

1925 ◽  
Vol 9 (2) ◽  
pp. 205-210 ◽  
Author(s):  
E. F. Hopkins ◽  
F. B. Wann
Keyword(s):  
Ph Value ◽  
Maximum Growth ◽  
Chemical Precipitation ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Alkaline Solutions ◽  
Culture Solution ◽  
Hydrogen Ion Concentration ◽  
Chlorella Sp ◽  
Nutrient Solutions

The data obtained in these experiments indicate clearly that unless the necessary precautions are taken to keep the iron of the culture medium in solution the results obtained by varying the H ion concentration will not represent the true effect of this factor on growth. The availability of iron in nutrient solutions has been the subject of numerous recent investigations and it is now known that iron is precipitated at the lower hydrogen ion concentrations, that the iron of certain iron salts is less likely to be precipitated than that of others, and that certain salts of organic acids tend to keep the iron in solution. In general, ferric citrate seems to be the most favorable source of iron. In addition to chemical precipitation, however, it is also possible for the iron to be removed by adsorption on an amorphous precipitate such as calcium phosphate. As this precipitate is frequently formed when nutrient solutions are made alkaline, this may account for the discordant results reported in the literature as to the availability of certain forms of iron. By omitting calcium from the culture solution iron can be maintained in a form available for growth in alkaline solutions by the addition of sodium citrate. In such solutions the maximum growth of Chlorella occurred at pH 7.5. The alkaline limit for growth has not been established as yet. In investigating the availability of iron at varying concentrations of the hydrogen ion, changes in the pH value of the solution during the course of an experiment should also be taken into account. This is especially important in unbuffered solutions. The differential absorption of the ions of ammonium salts may cause a marked increase in the hydrogen ion concentration, which in turn will cause an increase in the solubility of iron. In strongly buffered solutions as used in these experiments this effect is slight.

scholarly journals The heat of rigor of mammalian muscle

1930 ◽  
Vol 107 (750) ◽  
pp. 214-222 ◽  
Keyword(s):  
Lactic Acid ◽  
Heat Production ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Post Mortem ◽  
Rigor Mortis ◽  
Hydrogen Ion Concentration ◽  
Mammalian Muscle ◽  
Quantity Of Heat

The stiffening of muscle in rigor mortis is closely related to gelation of the muscle plasma (Smith, 1930). Neither the stiffening of the muscle (Hoet and Marks, 1926) nor the gelation of the plasma is immediately due to an increase in the hydrogen-ion concentration of the muscle, but, apart from the formation of lactic acid, no reaction is known to occur post-mortem which might be held responsible for the coagulation of the plasma. It was with a view to the detection of any such reaction that the following measurements of the heat production accompanying rigor mortis were made. The heat of rigor mortis has not previously been measured, although A. V. Hill (1912) measured the heat produced by frog’s muscles undergoing heat and chloroform rigor. The result suggested that the conversion of glycogen into lactic acid accounted for almost the whole of the heat produced. This has been found to be the case in the muscle of a normal well-fed rabbit when passing into rigor mortis , and also in the case of fatigued or exhausted muscle, but starved animals produce a larger quantity of heat than can be accounted for by the lactic acid produced.

scholarly journals Experimental pleural empyema model in rabbits: Why, how and what are the next steps

2014 ◽  
Vol 71 (5) ◽  
pp. 491-498 ◽  
Author(s):  
Vlado Cvijanovic ◽  
Danilo Vojvodic ◽  
Dragan Djurdjevic ◽  
Milena Jovic ◽  
Vojkan Stanic ◽  
...  
Keyword(s):  
Pleural Fluid ◽  
Ph Value ◽  
Lethal Dose ◽  
Pleural Empyema ◽  
Control Group ◽  
Mean Values ◽  
Experimental Animals ◽  
Fluid Analysis ◽  
The Mean ◽  
Experimental Group

Bacgraund/Aim. The use of new therapeutic methods to prevent development of fibrothorax as the final complication of the human pleural infections requires research with experimental animals. The aim of this study was to standardize the procedures for the establishment of our own experimental model of empyema in rabbits, since it should be able to offer similar conditions found in human pleural infections. Methods. This experiment included 15 chinchilla rabbits, weighing from 2.3 to 2.8 kg. There were 12 rabbits in the experimental group, while 3 rabbits formed the control group. On the first day, we administered 0.4-0.5 mL of turpentine in the right pleural space of the rabbits from the experimental group in order to provoke sterile exudative pleurisy. After 24 h we injected 1 mL of Staphylococcus aureus and 1 mL of Escherichia coli bacteria in the same concentration of 4.5 x 108 bacteria/mL. Thoracocentesis for the pleural fluid analysis was performed 24, 48, 72, and 96 h after bacteria instillation. In these pleural samples we estimated the number of leucocytes and the values of lactate dehydrogenase (LDH), glucose and pH in pleural fluid, as well as the presence of bacteria. We did not protect the animals with antibiotics, and on the day 7 of the experiment they were sacrificed with the lethal dose of barbiturate (iv). The lung from the empyemic side of all experimental animals and the lung of one control animal were histopathologically examined. Results. A total of 4 animals had a small amount of clear pleural fluids or there was no fluid obtained with thoracocentesis 24 and 48 h after the bacteria instillation. after the bacteria instillation. In the remaining 8 rabbits 24 h after bacteria administration the mean values (? SD) of the parameters monitored were as follows: Le 34.75 ? 6.13 x 109/L, LDH 17,000 ? 4,69 U/L, glucose 1.23 ? 0.45 mmol/L, and pH 6.975 ? 0.15. The obtained values met the criteria for the evaluation of effusion as pleural empyema or complex and complicated pleural effusion (LDH > 1000 U/L, glucose < 2.31 mmol/L and pH < 7.20). Bacterial cultures were positive in 5 out of 8 first pleural samples and in only 2 samples after 48 h of bacteria administration. There was a positive correlation between the number of leukocytes and the LDH value (r = 0.071, p < 0.001), and a negative correlation between the number of leukocytes and the glucose level (r = 0.864, p < 0.001), and the leukocytes number and pH of the pleural fluid (r = 0.894, p < 0.001). The mean glucose value increased after 48 h (3.23 ? 0.44 mmol/L), and the pH value rose after 72 h (7.22 ? 0.03) which was beyond the empyema level. Conclusion. The creation of the experimental empyema model is a very delicate work with uncertain success. Its value and importance are crucial for pleural pathology research. With the intention to obtain a more empyemic pleural reaction we created a model with two different human pathogen bacteria. We generated the satisfactory results, but not as good as those contained in some of the reference literature data.

Red Cell Oxygen Affinity, Hemoglobin Type, 2,3-Diphosphoglycerate, and pH as a Function of Fetal Development

PEDIATRICS ◽  
1979 ◽  
Vol 64 (4) ◽  
pp. 483-487 ◽  
Author(s):  
Harry Bard ◽  
Francois Teasdale
Keyword(s):  
Gestational Age ◽  
Significant Positive Correlation ◽  
Oxygen Affinity ◽  
Significant Negative Correlation ◽  
Ion Concentration ◽  
Red Cell ◽  
Adult Type ◽  
Hydrogen Ion Concentration ◽  
Positive Correlation ◽  
The Mean

Studies were carried out on fresh cord blood obtained at delivery from nonstressed normal fetuses ranging from 24 to 42 weeks of gestation, to determine the relationship of 2,3-diphosphoglycerate (DPG), the intracellular red cell and extracellular pH, and the proportions of adult and fetal hemoglobin in regulating the position of fetal red cell oxygen affinity in utero. There was a significant positive correlation between P50 and gestational age (r = .62, P &lt; .001), the linear regression increased from 17.8 to 22.5 mm Hg. There was also a significant positive correlation between P50 and the percentage of adult type hemoglobin (HbA) (r = .67, P &lt; .001). In contrast gestational age had no effect of 2,3-DPG levels, the mean and SD was 14.86 ± 2.04 mol/gm of Hb or ΔpH between plasma and red cell, the mean was 0.187 ± SD 0.032. However, there was a significant negative correlation between the intraerythrocyte hydrogen ion concentration and DPG level (r = .5, P &lt; .025). It is concluded therefore that the decrease in fetal oxygen affinity as gestation progresses is related mainly to the increase in the amount of HbA and the levels of DPG or ΔpH between plasma and red cells are not a function of gestational age.

Relationship of radius to pressure along the aorta in living dogs

1963 ◽  
Vol 18 (6) ◽  
pp. 1111-1117 ◽  
Author(s):  
Dali J. Patel ◽  
Flavio M. De Freitas ◽  
Joseph C. Greenfield ◽  
Donald L. Fry
Keyword(s):  
Cardiac Cycle ◽  
Branching Ratios ◽  
Ascending Aorta ◽  
Post Mortem ◽  
Arterial Tree ◽  
Mean Values ◽  
Living State ◽  
Instantaneous Pressure ◽  
The Mean ◽  
Relationship Of

The instantaneous pressure-radius relationship and mean dimensions were studied at various sites along the aorta in 30 dogs. The pressure-radius relationship was studied in the living state using an electrical caliper to measure the radius continuously through the cardiac cycle. The relative dimensions of the aortic tree at branching sites were calculated from Jeltrate casts made immediately post mortem. The results indicate: 1) The value of ΔR/ΔP and the mean radius decreased with distance along the aorta. 2) The calculated value for Ep, the “pressure-strain elastic modulus” increased monotonically from the ascending aorta to the bifurcation. 3) An “average” arterial tree was constructed from the mean values of the radius obtained from the caliper data and the branching ratios obtained from the casts. elastic properties, aorta; dimensions, dog aorta Submitted on March 5, 1963

scholarly journals Acidity of Snow and its Reduction by Alkaline Aerosols

1985 ◽  
Vol 6 ◽  
pp. 92-94 ◽  
Author(s):  
Motoi Kumai
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Electric Power Plants ◽  
Ph Values ◽  
Calcium Silicon ◽  
The Mean ◽  
Snow Crystals ◽  
Snow Samples

Snow crystals scavenge aerosols in the atmosphere during the processes of growth and precipitation. Several kinds of flyash are found in acid snow by scanning electron microscope examination. Flyash particles from coal fired electric power plants in Fairbanks, Alaska, were found to be spherical or irregular in shape with a 0.2 to 50μm diameter, and were rich in calcium, silicon, aluminum and iron. The pH of 35 snow samples in Fairbanks ranged from 5.60 to 7.48. The acid snow was changed to alkaline snow by dry fallout of calcium-rich flyash from the electric power plants, which were using calcium-rich Alaskan coal.Flyash particles from three oil fired heating plants in Hanover, New Hampshire, were spherical and 10 to 80 μm in diameter, with gas escape holes, and were always sulfur rich. The pH values of fresh snow from 44 snowfalls were measured to range from pH 3.96 to 5.45 in Hanover. The mean hydrogen ion concentration was calculated to be 10-448 mol/L for 22 snowfalls in 1980-84, and 10-4 mol/L for 22 snowfalls in 1972-73.

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