bluuebunny/crossref_metadata_2025_split huggingface dataset:
COMPARATIVE STUDIES ON RESPIRATION
Authors: Smith Edith Philip 
Published: May 2004

Using these concentrations of ether (1 per cent, 3.65 per cent, 7.3 per cent), the following conclusions may be drawn.
1. The first effect of ether is to cause a depression in the rate of respiration. This is followed by a rapid rise above normal, which in turn is succeeded by a fall.
2. With all these concentrations the respiration is ultimately reduced to approximately the same level; the stronger the ether, the less time required to produce this result.
3. Even when the respiration has been reduced below normal, recovery is possible on removal from the ether, and appears to be complete, if sufficient time is allowed. If, however, the rate has been too far depressed, no recovery is possible.
4. These results extend those of Irwin on frog eggs and Fundulus embryos.
THE EFFECT OF HYDROGEN ION CONCENTRATION ON THE PRODUCTION OF CARBON DIOXIDE BY BACILLUS BUTYRICUS AND BACILLUS SUBTILIS
Authors: Brooks Matilda Moldenhauer 
Published: May 2004

1. The maximum rate of CO2 production of Bacillus butyricus was found to be at a pH value of 7; of Bacillus subtilis at pH 6.8. If the pH value be raised or lowered there is a progressive decrease in the rate of production of CO2.
2. Spontaneous recovery follows the addition of alkali to either organism, while addition of acid is followed by recovery only upon addition of an equivalent amount of alkali, and is not complete except when the amount of acid is very small.
THE INACTIVATION OF TRYPSIN
Authors: Northrop John H. 
Published: May 2004

1. A study has been made of the equilibrium existing between trypsin and the substances formed in the digestion of proteins which inhibit its action.
2. This substance could not be obtained by the hydrolysis of the proteins by acid or alkali. It is dialyzable.
3. The equilibrium between this substance (inhibitor) and trypsin is found to agree with the equation,
trypsin + inhibitor ⇌ trypsin-inhibitor
The equilibrium is reached instantaneously and is independent of the substrate concentration. If it be further assumed that the rate of hydrolysis is proportional to the concentration of the free trypsin and that the equilibrium conforms to the law of mass action, it is possible to calculate the experimental results by the application of the law of mass action.
4. The equilibrium has been studied by varying (a) the concentration of the inhibiting substance, (b) the concentration of trypsin, (c) the concentration of gelatin, and (d) the concentration of trypsin and inhibitor (the relative concentration of the two remaining the same). In all cases the results agree quantitatively with those predicted by the law of mass action.
5. It was found that the percentage retarding effect of the inhibiting substance on the rate of hydrolysis is independent of the hydrogen ion concentration between pH 6.3 and 10.0.
6. The fact that the experimental results agree with the mechanism outlined under 3, is contrary to the assumption that any appreciable amount of trypsin is combined with the gelatin at any one time; i.e., the velocity of the hydrolysis must depend on the time required for such a compound to form rather than for it to decompose.
7. The experiments may be considered as experimental proof of the validity of Arrhenius' explanation of Schütz's rule as applied to trypsin digestion.
8. Inactivated trypsin does not enter into the equilibrium.
THE INACTIVATION OF TRYPSIN
Authors: Northrop John H. 
Published: May 2004

1. The rate of inactivation of purified trypsin solutions approximates closely that demanded by the monomolecular formula. The more carefully the solution is purified the closer the agreement with the formula.
2. The products formed by the action of trypsin on proteins renders the trypsin more stable. Gelatin and glycine have no effect.
3. The rate of inactivation of trypsin solutions containing these products does not follow the course of a monomolecular reaction but becomes progressively slower than the predicted rate.
4. The protective action of these substances is much greater if they are added all at once at the beginning of the experiment than if they are added at intervals.
These observations may be quantitatively accounted for by the hypothesis that a compound is formed between trypsin and the inhibiting substance which is stable as well as inactive, and that the rate of decomposition depends on the amount of uncombined trypsin present.
5. Trypsin is most stable at a pH of 5 and is rapidly destroyed in strongly acid or alkaline solution.
6. The protective effect of the inhibiting substances is small on the acid side of pH 5, increases from pH 5 to 7, and then remains approximately constant.
THE PHYSIOLOGY OF THE RESPIRATION OF FISHES IN RELATION TO THE HYDROGEN ION CONCENTRATION OF THE MEDIUM
Authors: Powers Edwin B. 
Published: May 2004

1. The ability of marine fishes to absorb oxygen at low tension from the sea water is more or less dependent upon the hydrogen ion concentration of the water.
2. The ability of fishes to withstand wide variations in the range of hydrogen ion concentration of the sea water can be correlated with their habitats. The fishes that are most resistant to a wide variation in the hydrogen ion concentration are most cosmopolitan in their habitat. Those that are least resistant to a variation in the hydrogen ion concentration are the most restricted in their range of habitat.
3. There is a close correlation between the optimum condition of the sea water for the absorption of oxygen at low tension by the herring (Clupea pallasii), the condition of the sea water to which they react positive and that in which they are found most abundantly.
4. It is suggested that the variation in the ability to absorb oxygen at low tension at a given pH of individuals of a species is dependent upon the alkaline reserve of the blood of the individual fish.
THE INFLUENCE OF FEEDING THE ANTERIOR LOBE OF THE HYPOPHYSIS ON THE SIZE OF AMBYSTOMA TIGRINUM
Authors: Uhlenhuth Eduard 
Published: May 2004

1. Animals of the species Ambystoma tigrinum when fed anterior lobe can reach a size far in excess of that of animals fed earthworms and presumably also of that of liver-fed animals.
2. Liver produces a rate of growth as high as that resulting from anterior lobe-feeding, but maintains growth only, until the animals reach a definite size far below that of anterior lobe-fed animals.
THE TEMPERATURE COEFFICIENT OF PHAGOCYTOSIS
Authors: Fenn Wallace O. 
Published: May 2004

1. The experiments of Madsen and Watabiki on the effect of temperature on the phagocytosis of bacteria are discussed and a new analysis of their curves is given, showing that the rate of phagocytosis is very nearly a logarithmic function of the temperature from 0° to 35°C.; i.e., Q10 is constant over that range and is equal to 2.0.
2. New experiments are reported on the effect of temperature on the phagocytosis of quartz and carbon particles of uniform sizes, showing a marked increase in the temperature coefficient below 30°C.
THE THEORETICAL RESPONSE OF LIVING CELLS TO CONTACT WITH SOLID BODIES
Authors: Fenn Wallace O. 
Published: May 2004

The theoretical behavior of a hypothetical fluid cell in contact with flat and curved solid surfaces is discussed from the point of view of surface tension.
An equation is derived for calculating the equilibrium position of the cell on a flat surface in terms of the surface tensions between the cell and the plasma, the plasma and the solid surface, and the solid surface and the cell. It is shown that the same equilibrium is predicted from consideration of the contact angle between the cell and the solid body.
The relative surface energy has been calculated at various stages in the ingestion of a solid particle by a fluid cell four times as large in diameter, and it is thus shown that no particle will be ingested until the surface tensions are such that the cell would spread to infinity on a flat surface of the same substance. Here again the same equilibrium is predicted from considerations of the contact angle.
The adhesiveness of blood cells to solid substances is shown to be a pure surface tension phenomenon, but in most reactions between living cells and solid bodies the fluidity of the protoplasm is also a factor of prime importance.
The frequent occurrence of adhesiveness as a property of cells in contact with solid bodies is due in part to the fact that, by so adhering, the surface area of the cell not touching the solid is decreased.
THE MECHANISM OF GRANULAR GROWTH OF RABBIT SEPTICEMIA BACILLUS TYPE G
Authors: De Kruif Paul H. 
Published: May 2004

The acid agglutination optimum of Microbes D and G is not independent of the nature of the buffer mixture. Glycocoll-HCl buffer mixtures cause complete flocculation at high CH+ (2.7 to 2.4), at which points little or no flocculation occurs with the Na lactate-lactic acid buffer series.
Beef infusion has the property of broadening the acid agglutination optimum of both Microbes D and G, bacilli of rabbit septicemia. This extension is in the direction of a lower CH+.
There is no evidence that the beef infusion has the power, per se, of agglutinating these organisms. It would seem merely to increase their sensitiveness to sedimentation in the presence of H ions.
The data presented explain the mechanism of the granular growth character of Microbe G in liquid media as compared to the diffuse growth of Microbe D.
Peptone (Fairchild), contrary to beef infusion, shifts the acid agglutination optimum of Microbes D and G in the direction of a higher CH+. Strong concentrations of peptone exhibit an inhibitory effect on the agglutination of Microbe D in the optimum zone.
THE AGGLUTINATION OF RED BLOOD CELLS IN THE PRESENCE OF BLOOD SERA
Authors: Coulter Calvin B. 
Published: May 2004

1. The addition of blood serum displaces the optimum for agglutination of red blood cells in a salt-free medium to the reaction characteristic of flocculation of the serum euglobulin.
2. This effect is not due merely to a mechanical entanglement of the cells by the precipitating euglobulin, since at reactions at which the latter is soluble it protects the cells from the agglutination which occurs in its absence.
3. A combination of some sort appears therefore to take place between sheep cells and sheep, rabbit, and guinea pig serum euglobulin, and involves a condensation of the serum protein upon the surface of the red cell.
4. At the optimal point for agglutination of persensitized cells both mid- and end-piece of complement combine with the cells.
5. Agglutination is closely related to an optimal H ion concentration in the suspending fluid, and probably of the cell membrane, and not to a definite reaction in the interior of the cell.
THE INFLUENCE OF X-RAYS ON THE PROPERTIES OF BLOOD
Authors: Hussey Raymond G. 
Published: May 2004

When rabbits are exposed to x-radiation as described, there results a definite change in the
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ratio of their plasma. This change is evidently one which defines a state of uncompensated alkali excess.
The time required for a maximum change in the chemical reaction is the same as that required for a maximum change in the decrease of leucocytes.
Sodium bicarbonate injected into the peritoneal cavity is followed by results identical with those observed following exposure to x-rays. The maximum changes occur in a shorter time following bicarbonate injection, but the relation between chemical and morphological changes are the same.
We consider this analogy to be an important one in that it is suggestive of a relationship between the effect of salt and the effect of x-rays.
KINETICS OF THE BIOLUMINESCENT REACTION IN CYPRIDINA. II
Authors: Amberson William R. 
Published: May 2004

1. The decay curve of the light produced in the course of the luminescent reaction in Cypridina is, after the first second, in complete agreement with the theoretical expectation for a monomolecular reaction, if light intensity at any instant is assumed to be proportional to reaction velocity at that instant. It is shown that for such a reaction
log I = - kt + log Ak
and that the experimental values satisfy this equation.
2. The first second or two of the reaction is characterized by a brilliant initial flash, whose value is much too high to accord with the succeeding intensities and with the above formula. It is suggested that this initial high reaction velocity is an indication of a heterogeneous system.
3. Identical solutions run simultaneously give decay curves which check within the limits of the photographic error.
4. Stirring does not affect the reaction velocity or the form of the decay curve.
5. Reaction velocity is proportional to enzyme concentration, over the range of concentrations used in the study.
6. Changes in the concentration of the substrate do not affect the value of k, when all other factors are held constant. A diminution of luciferin concentration results only in a decrease in the value of the y-intercept, Log Ak, the two straight line plottings for two different concentrations being parallel.
7. The temperature coefficient is high, being about 4.5 for the 15–25° interval, and 3.0 for the 25–35° interval.
A NOTE ON THE ACTION OF CURARE, ATROPINE, AND NICOTINE ON THE INVERTEBRATE HEART
Authors: Carlson A. J. 
Published: May 2004

1. The alkaloids (curare, atropine, and nicotine) in molluscs and arthropods stimulate and paralyze the central nervous system and peripheral (visceral) ganglia, but do not paralyze the motor nerve endings to skeletal or visceral muscle.
2. They stimulate and paralyze the denervated heart.
3. They paralyze or block the cardioinhibitory nerves, but not the cardioaccelerator nerves.
4. In the Limulus heart these drugs act primarily on the heart ganglion, not on the heart muscle or the intrinsic motor nerve fibers.
ON THE EQUILIBRIUM CONDITION BETWEEN BLOOD SERUM AND SEROUS CAVITY FLUIDS
Authors: Loeb Robert F. , Atchley Dana W. , Palmer Walter W. ,   With the Assistance of Ethel M. Benedict.
Published: May 2004

1. Comparative studies of blood serum and edema fluid from the same individual indicate that, regardless of the pathological condition present, whether the fluid be "transudate" or "exudate," certain definite qualitative chemical relations obtain.
2. The chief feature of these relations is that the edema fluid contains more Cl and less K than the blood serum; while the Na, HCO3, Ca, urea, glucose, and non-protein nitrogen exist in approximately the same concentrations in the serum and in the edema fluid. The freezing point is also the same in both fluids, while the specific conductivity is constantly higher in the edema fluid.
3. The above mentioned variations between the edema fluid and the serum appear to be related to the difference in the concentration of protein in the two solutions.
4. The relationships between blood serum and edema fluid seem to result from a simple membrane equilibrium, influenced in part by the proteins present.
THE STABILITY OF BACTERIAL SUSPENSIONS
Authors: Northrop John H. , De Kruif Paul H. 
Published: May 2004

1. Measurements have been made of the potential and of the cohesive force at the surface of Bacillus typhosus and the bacillus of rabbit septicemia in solutions of various salts and acids.
2. Electrolytes in low concentration (0.01 N) affect primarily the potential, and in high concentration decrease the cohesive force.
3. As long as the cohesive force is not affected, agglutination occurs whenever the potential is reduced below about 15 millivolts.
4. When the cohesive force is decreased the critical potential is also decreased, and in concentrated salt solution no agglutination occurs even though there is no measurable potential.
THE FLOCCULATION OF BACTERIA BY PROTEINS
Authors: Eggerth Arnold H. , Bellows Margaret 
Published: May 2004

1. The effect of adding pure proteins to bacterial suspensions at different H ion concentrations has been studied.
2. The zone of flocculation of protein-treated bacteria bears a significant relationship to the isoelectric point of the protein used. With the higher concentration of protein, agglutination occurs at or near the isoelectric point of that protein; at reactions acid to this, the bacteria carry a positive charge and are not agglutinated. With diminishing concentration of protein, the zone of flocculation shifts toward and goes beyond that characteristic of the untreated bacteria. This occurs both in the presence and absence of salts.
3. A diversity of other suspensions, such as sols of gold, mastic, cellulose nitrate, cellulose acetate, Fe(OH)3, oil emulsions, and erythrocytes, have been found by ourselves and others to exhibit a similar altered stability when treated with proteins in the same way.
CELL PENETRATION BY ACIDS
Authors: Crozier W. J. 
Published: May 2004

Measurements of the penetration of tissue from Chromodoris zebra are believed to show that a determining factor in penetration involves the establishment of a critical pH (near 3.5) in relation to superficial cell proteins. The rapidity with which this state is produced depends upon acid strength, and upon some property of the acid influencing the speed of absorption; hence it is necessary to compare acids within groups of chemical relationship.
The actual speed of penetration observed with any acid is dependent upon two influences: preliminary chemical combination with the outer protoplasm, followed by diffusion. The variation of the temperature coefficient of penetration velocity with the concentration of acid, and the effect of size (age) of individual providing the tissue sample agree in demonstrating the significant part played by diffusion. In comparing different acids, however, their mode of chemical union with the protoplasm determines the general order of penetrating ability.
CATAPHORETIC CHARGES OF COLLODION PARTICLES AND ANOMALOUS OSMOSIS THROUGH COLLODION MEMBRANES FREE FROM PROTEIN
Authors: Loeb Jacques 
Published: May 2004

1. It had been shown in previous papers that when a salt solution is separated from pure water by a collodion membrane, water diffuses through the membrane as if it were positively charged and as if it were attracted by the anion of the salt in solution and repelled by the cation with a force increasing with the valency. In this paper, measurements of the P.D. across the membrane (E) are given, showing that when an electrical effect is added to the purely osmotic effect of the salt solution in the transport of water from the side of pure water to the solution, the latter possesses a considerable negative charge which increases with increasing valency of the anion of the salt and diminishes with increasing valency of the cation. It is also shown that a similar valency effect exists in the diffusion potentials between salt solutions and pure water without the interposition of a membrane.
2. This makes it probable that the driving force for the electrical transport of water from the side of pure water into solution is primarily a diffusion potential.
3. It is shown that the hydrogen ion concentration of the solution affects the transport curves and the diffusion potentials in a similar way.
4. It is shown, however, that the diffusion potential without interposition of the membrane differs in a definite sense from the P.D. across the membrane and that therefore the P.D. across the membrane (E) is a modified diffusion potential.
5. Measurements of the P.D. between collodion particles and aqueous solutions (ϵ) were made by the method of cataphoresis, which prove that water in contact with collodion particles free from protein practically always assumes a positive charge (except in the presence of salts with trivalent and probably tetravalent cations of a sufficiently high concentration).
6. It is shown that an electrical transport of water from the side of water into the solution is always superposed upon the osmotic transport when the sign of charge of the solution in the potential across the membrane (E) is opposite to that of the water in the P.D. between collodion particle and water (ϵ); supporting the theoretical deductions made by Bartell.
7. It is shown that the product of the P.D. across the membrane (E) into the cataphoretic P.D. between collodion particles and aqueous solution (ϵ) accounts in general semiquantitatively for that part of the transport of water into the solution which is due to the electrical forces responsible for anomalous osmosis.
THE STABILITY OF BACTERIAL SUSPENSIONS
Authors: De Kruif Paul H. , Northrop John H. 
Published: May 2004

1. The removal of antibody from Bacillus typhosus is no more complete at pH 3 than at pH 7.
2. Approximately twelve agglutinating doses are firmly combined with the organisms. Immune body in excess of this amount is easily removable by distilled water.
3. A method of testing for the presence of immune body on the organism is described which depends on the difference in the acid agglutination of sensitized and unsensitized organisms.
4. Repeated washing in distilled water will serve to remove all the immune body from sensitized bacteria.
THE EQUIVALENCE OF AGE IN ANIMALS
Authors: Brody Samuel , Ragsdale Arthur C. 
Published: May 2004

1. A method of plotting growth curves is presented which is considered more useful than the usual method in bringing out a number of important phenomena such as the equivalence of age in different animals, difference in the shape and duration of corresponding growth cycles in different animals, and also in determinating the age of maxima without resorting to complicated mathematical computations.
2. It is suggested that after the third cycle is past the conceptional age of the maximum of the third cycle may be taken as the age of reference for estimating the equivalent physiological ages in different animals. Before the age of the third cycle, the maxima of the second and first cycles are most conveniently used as points of reference.
3. It is shown that the product of the conceptional age of the maximum of the third cycle by 13, gives a value which is, with the possible exception of man, very near to the normal duration of life of animals under the most favorable conditions of life. In other words, the equivalent physiological ages in different animals bear an approximately constant linear relation to the duration of their growth periods.
4. Attention is called to certain differences in the shape and duration of the corresponding growth cycles in different animals and of the effect of sex on these cycles.
THE PERMEABILITY OF CELLS FOR OXYGEN AND ITS SIGNIFICANCE FOR THE THEORY OF STIMULATION
Authors: Harvey E. Newton 
Published: May 2004

It can be demonstrated by an indicator method that living cells are as freely permeable to oxygen as dead cells, and that sudden admission of oxygen to the cell cannot account for increased oxidation as a result of stimulation. Oxygen penetrates as readily as carbon dioxide among the acids and ammonia among the alkalies.
Exposure of living plant cells to high oxygen pressures does not initiate certain oxidations (except after some hours), which proceed readily in dead plant cells in the air. In the light of the preceding statement, about the permeability of cells for oxygen, this is interpreted to mean that more oxygen enters the cell at high pressure, but that the reacting substances (chromogen and oxidase) are kept apart by some phase boundary as long as the cell is alive. Increased oxygen concentration eventually produces injury to the cell.
SOME ASPECTS OF SELECTIVE ABSORPTION
Authors: Osterhout W. J. V. 
Published: May 2004

1. A mechanism exists in Valonia which prevents certain substances (Na, Mg, Ca, SO4) from reaching as high a concentration inside the cell as in the sea water which surrounds it.
2. A trapping mechanism also exists which causes K to accumulate in the cell in a concentration far in excess of that found in sea water. Practically all the K in the cell exists in the form of KCl.
3. The concentration of Cl does not differ greatly within and without.
4. These facts are not in harmony with present theories regarding the accumulation of K in living cells.