bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECT OF VALENCE OF IONS ON CELLULAR PERMEABILITY TO WATER
Authors: Lucké Balduin , McCutcheon Morton 
Published: May 2004

1. Permeability to water in unfertilized eggs of the sea urchin, Arbacia punctulata, was studied by measuring the rate of swelling in hypotonic dextrose solution.
2. Permeability is greatly affected by addition of electrolytes in low concentration.
3. A decrease in permeability to water was found with increasing valence of the cation, using a series of cobaltammine chlorides in which the valence of the cation ranged from 1 to 6.
4. Conversely, an increase in permeability to water was found with increasing valence of the anion, using two series of potassium salts in which the valence of the anion ranged from 1 to 4, and 1 to 3, respectively.
5. It is concluded that the effect of electrolytes on permeability to water depends chiefly on the sign and the number of charges on the ion, in the sense that positive ions decrease permeability to water, while negative ions increase permeability to water; and the effectiveness of the ion is greater the higher its valence.
6. Antagonism has been demonstrated between cations and anions in their effect on permeability, and the method employed permits quantitative study of such antagonism.
ON PYRIDINE HEMOCHROMOGEN
Authors: Mirsky A. E. , Anson M. L. 
Published: May 2004

1. Cyanide hemochromogen probably contains one cyanide group per heme group.
2. The equilibrium between pyridine hemochromogen and its components, pyridine and reduced heme, is complicated to an unknown extent by the precipitation of reduced heme and the aggregation of pyridine hemochromogen.
3. These complications were not taken into account in R. Hill's experiments on pyridine hemochromogen.
4. Even if Hill's experiments are sound they do not prove his conclusion that pyridine hemochromogen contains two pyridine groups per heme group.
PHOTOSYNTHESIS AS A FUNCTION OF LIGHT INTENSITY AND OF TEMPERATURE WITH DIFFERENT CONCENTRATIONS OF CHLOROPHYLL
Authors: Emerson Robert 
Published: May 2004

1. Photosynthesis reaches its maximum rate at about the same light intensity over the whole range of chlorophyll concentrations studied.
2. Over this range the process shows the same relationship to temperature. The value of the temperature characteristic decreases gradually as the temperature rises.
3. The rate of photosynthesis is more depressed by prussic acid the lower the chlorophyll concentration.
4. These results are interpreted as indicating that photosynthesis possibly involves an autocatalytic reaction, and that chlorophyll must play some part in the process in addition to its rôle in the absorption of light.
THE MECHANISM OF COMPLEMENT FIXATION
Authors: Eagle Harry 
Published: May 2004

1. Complement fixation is obtained in every antigen-antibody reaction involving the presence or formation of a heterogeneous phase (red cells, bacteria, precipitate).
2. The physical constants of fixation (temperature coefficient, velocity, quantitative relationships between the reactants) are those commonly associated with adsorption processes, and are the same in the three types of fixation studied.
3. All the in vitro immune reactions involve an aggregation of immune-serum globulins upon the surface of the antigen. It has been shown that the "fixation" of complement is an adsorption by the aggregates so formed; whether these aggregates are visible as a flocculent precipitate (e.g., sheep serum vs. anti-serum) or concentrated as a surface film on a cellular antigen (sensitized cells; agglutinated bacteria), the reaction is fundamentally the same.
4. As yet, it is unknown whether this adsorption is determined by the physical state of the precipitate, and thus, differs only quantitatively from that by Kaolin, charcoal, normal bacteria, heat-denatured proteins, etc.; or whether the comparatively enormous avidity of these aggregates for complement is due to a specific chemical affinity.
UNEQUAL DISTRIBUTION OF IONS IN A COLLODION CELL
Authors: Northrop John H. 
Published: May 2004

The properties of dry collodion membranes previously described allow the prediction that cells of these membranes will concentrate solutes under certain conditions. Three such cases have been studied experimentally.
1. A membrane containing thiosulphate and immersed in a solution of iodine concentrates iodide ion.
2. A membrane containing sodium chromate and immersed in mercury chloride concentrates chloride ion.
3. A membrane containing calcium carbonate and immersed in acetic acid concentrates acetate ions.
THE RESPIRATION OF LUMINOUS BACTERIA AND THE EFFECT OF OXYGEN TENSION UPON OXYGEN CONSUMPTION
Authors: Shoup Charles S. 
Published: May 2004

1. The respiration of luminous bacteria has been studied by colorimetric and manometric methods.
2. Limulus oxyhaemocyanin has been used as a colorimetric indicator of oxygen consumption and indicator dyes were used for colorimetric determination of carbon dioxide production.
3. The Thunberg-Winterstein microrespirometer has been used for the measurement of the rate of oxygen consumption by luminous bacteria at different partial pressures of oxygen.
4. The effect of oxygen concentration upon oxygen consumption has been followed from equilibrium with air to low pressures of oxygen.
5. Luminous bacteria consume oxygen and produce carbon dioxide independent of oxygen pressures from equilibrium with air (152 mm.) to approximately 22.80 mm. oxygen or 0.03 atmosphere.
6. Dimming of a suspension of luminous bacteria occurs when oxygen tension is lowered to approximately 2 mm. Hg (0.0026 atmosphere) and when the rate of respiration becomes diminished one-half.
7. Pure nitrogen stops respiratory activity and pure oxygen irreversibly inhibits oxygen consumption.
8. The curve for rate of oxygen consumption with oxygen concentration is similar to curves for adsorption of gasses at catalytic surfaces, and agrees with the Langmuir equation for the expression of the amount of gas adsorbed in unimolecular layer at catalytic surfaces with gas pressure.
9. A constant and maximum rate of oxygen consumption occurs in small cells when oxygen concentration becomes sufficient to entirely saturate the surface of the oxidative catalyst of the cell.
THE SIZE OF BACTERIA AS THE CAUSE OF THE LOGARITHMIC ORDER OF DEATH
Authors: Rahn Otto 
Published: May 2004

Death of unicellular organisms is brought about by the inactivation of a certain number of essential molecules in the cell.
If the number of these essential molecules is only one per cell, the order of death is the same as if the cell were identical with this molecule; the order of death is logarithmic following the mass law.
If more than one molecule must be inactivated before the cell dies, the order of death is not logarithmic. With 2 or 3 molecules, it still resembles the logarithmic order, but with an increasing number of reacting molecules, it approaches more and more the order of death known with higher organisms, namely a period of no death, followed by a comparatively short period of rapid death.
The decision whether or not the logarithmic order exists, should be based upon the constancy of the death rate
See PDF for Equation.
The existence of a straight line when logarithms of survivors are plotted against time, is not sufficient proof unless the initial number of cells is included.
These deductions are made with the assumption that all organisms are exactly alike, and show no individual variations or graded resistance.
With most bacteria, the order of death is so nearly logarithmic that death must be brought about by the inactivation of only one molecule, though there may be several molecules of this same type in each cell.
DISSIMILARITY OF INNER AND OUTER PROTOPLASMIC SURFACES IN VALONIA. II
Authors: Damon E. B. 
Published: May 2004

In measurements of P.D. across the protoplasm in single cells, the presence of parallel circuits along the cell wall may cause serious difficulty. This is particularly the case with marine algae, such as Valonia, where the cell wall is imbibed with a highly conducting solution (sea water), and hence has low electrical resistance. In potential measurements on such material, it is undesirable to use methods in which the surface of the cell is brought in contact with more than one solution at a time. The effect of a second solution wetting a part of the cell surface is discussed, and demonstrated by experiment.
From further measurements with improved technique, we find that the value previously reported for the P.D. of the chain
Valonia sap | Valonia protoplasm | Valonia sap
is too low, and also that the P.D. undergoes characteristic changes during experiments lasting several hours. The maximum P.D. observed is usually between 25 and 35 mv., but occasionally higher values (up to 82 mv.) are found.
The appearance of the cells several days after the experiment, and the P.D.'s which they give with sea water, indicate that no permanent injury has been received as a result of exposure to artificial sap. If such cells are used in a second measurement with artificial sap, however, the form of the P.D.-time curve indicates that the cells have undergone an alteration which persists for a long time.
On the basis of the theory of protoplasmic layers, an attempt has been made to explain the observed changes in P.D. with time, assuming that these changes are due to penetration of KCl into the main body of the protoplasm.
OXIDATION-REDUCTION POTENTIALS AND THE POSSIBLE RESPIRATORY SIGNIFICANCE OF THE PIGMENT OF THE NUDIBRANCH CHROMODORIS ZEBRA
Authors: Preisler Paul W. 
Published: May 2004

1. Oxidation-reduction potential methods have been applied to a study of the blue-purple pigment present in solution in the blood and in the tissue cells of the nudibranch Chromodoris zebra.
2. The blue-purple pigment and its yellow reduction product form a reversible system whose Eo' = x0.102 volts at pH 7.0 and whose valence change from oxidant to reductant appears to be one.
3. The system is unlike oxyhemoglobin-hemoglobin in the mode of oxygen transfer. Its rôle as a possible respiratory material is discussed.
A METHOD FOR THE QUANTITATIVE DETERMINATION OF BACTERIOPHAGE
Authors: Krueger Albert P. 
Published: May 2004

1. In the case of the staphylococcus and antistaphylococcus phage studied, with the total volume of the mixture being kept constant, there exists a definite quantitative relationship between CPhage and the time required to reduce a particular concentration of growing phage-susceptible bacteria to an arbitrary turbidity end-point.
2. This relationship furnishes a basis for the quantitative estimation of bacteriophage. A method is described having an accuracy within ±5 per cent.
THE KINETICS OF PENETRATION
Authors: Jacques A. G. , Osterhout W. J. V. 
Published: May 2004

The rate of penetration of CO2 into living cells of Valonia has been studied at high and low pH values.
The time curve of penetration appears to be of the first order but with a "velocity constant" which falls off from the start.
The evidence indicates little penetration of ions. This is shown by (a) the similarity of velocity "constants" at high and low pH values, (b) the rate of penetration, which remains constant as long as the external concentration of undissociated CO2 remains constant no matter how much the concentration of ions varies.
CALCULATIONS OF BIOELECTRIC POTENTIALS
Authors: Osterhout W. J. V. 
Published: May 2004

The P.D. of 0.01 M vs. 0.001 M KCl (concentration effect) in Nitella is 54.7 mv. and that of NaCl is 20.9 mv. The P.D. of 0.01 M NaCl vs. 0.01 M KCl is 82.9 mv.
If we assume that diffusion potentials predominate we may calculate the relative mobilities of the ions in the outer layer of the protoplasm. If we put vCl = 1 we obtain uK = 85.45 and uNa = 2.18. (These values depend upon the fact that the mean ionic activities in this layer must be equal at equilibrium to the mean ionic activities in the external solution.)
Using these values the calculated P.D. of 0.01 M NaCl vs. 0.005 M NaCl + 0.005 M KCl is 66 mv. (the observed value is 68.8 mv.) and the conductance of KCl in the outer layer of the protoplasm is 27 times as great as that of NaCl (the observed conductance for the whole protoplasm is 25 to 50 times greater for KCl than for NaCl).
Calculations on the basis of phase boundary potentials are less satisfactory.
THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL
Authors: Blinks L. R. 
Published: May 2004

Many of the freshly gathered cells of Valonia ventricosa have a resistance to direct current which is variable and depends on the potential applied. It is low when low potentials are applied and rises sharply at higher values. The rise may be more than 100 per cent in the cell as a whole, which is equivalent to several hundred per cent in the protoplasm alone. The rise becomes less as the cells stand in the laboratory, until a maximum is reached at all applied potentials, low and high, below the breakdown value (about 100 mv.): the cells are then said to be in a constant state.
During the variable state, the resistance rises when the positive current enters the protoplasm from outside, and falls when it passes out from the vacuole (this is determined by killing one end with chloroform).
The rise of resistance becomes faster with closely succeeding applications of potential. This is ascribed to the removal from the protoplasm of ions to which it is reversible. There is some evidence that these may be potassium ions.
Much of the apparent resistance rise may be accounted for by a back E.M.F. caused by the flow of current.
THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL
Authors: Blinks L. R. 
Published: May 2004

Electrical resistance and polarization were measured during the passage of direct current across a single layer of protoplasm in the cells of Valonia ventricosa impaled upon capillaries. These were correlated with five stages of the P.D. existing naturally across the protoplasm, as follows:
1. A stage of shock after impalement, when the P.D. drops from 5 mv. to zero and then slowly recovers. There is very little effective resistance in the protoplasm, and polarization is slight.
2. The stage of recovery and normal P.D., with values from 8 to 25 mv. (inside positive). The average is 15 mv. At first there is little or no polarization when small potentials are applied in either direction across the protoplasm, nor when very large currents pass outward (from sap to sea water). But when the positive current passes inward there is a sudden response at a critical applied potential ranging from 0.5 to 2.0 volts. The resistance then apparently rises as much as 10,000 ohms in some cases, and the rise occurs more quickly in succeeding applications after the first. When the potential is removed there is a back E.M.F. displayed. Later there is also an effect of such inward currents which persists into the first succeeding outward flow, causing a brief polarization at the first application of the reverse potential. Still later this polarization occurs at every exposure, and at increasingly lower values of applied potentials. Finally there is a "constant" state reached in which the polarization occurs with currents of either direction, and the apparent resistance is nearly uniform over a considerable range of applied potential.
3. A state of increased P.D.; to 100 mv. (inside positive) in artificial sap; and to 35 or 40 mv. in dilute sea water or 0.6 M MgSO4. The polarization response and apparent resistance are at first about as in sea water, but later decrease.
4. A reversed P.D., to 50 mv. (outside positive) produced by a variety of causes, especially by dilute sea water, and also by large flows of current in either direction. This stage is temporary and the cells promptly recover from it. While it persists the polarization appears to be much greater to outward currents than to inward. This can largely be ascribed to the reduction of the reversed P.D.
5. Disappearance of P.D. caused by death, and various toxic agents. The resistance and polarization of the protoplasm are negligible.
The back E.M.F. of polarization is shown to account largely for the apparent resistance of the protoplasm. Its calculation from the observed resistance rises gives values up to 150 mv. in the early stages of recovery, and later values of 50 to 75 mv. in the "constant" state. These are compared with the back E.M.F. similarly calculated from the apparent resistance of intact cells.
The electrical capacitance of the protoplasm is shown by the time curves to be of the order of 1 microfarad per cm.2 of surface.
THE EFFECT OF LOW PRESSURES ON CELL OXIDATION
Authors: Cook S. F. 
Published: May 2004

1. A method is described for measuring tissue oxidation under reduced barometric pressure.
2. The oxygen uptake of yeast is diminished by low barometric pressures to a greater extent than by a reduction of the partial pressure of oxygen, to a corresponding degree, at atmospheric pressure.
3. This effect of low pressure is not observed with certain in vitro oxidation systems.
4. The anaerobic respiration (carbon dioxide production) of yeast is not at all affected by low pressures.
5. The inhibition of tissue oxidation caused by carbon monoxide is removed by lowering the pressure.
CHEMICAL STIMULATION BY ALCOHOLS IN THE BARNACLE, THE FROG AND PLANARIA
Authors: Cole William H. , Allison J. B. 
Published: May 2004

1. The stimulating efficiencies of some normal primary aliphatic alcohols have been determined for the barnacle, the frog, and Planaria, under conditions which do not involve narcosis or simultaneous stimulation by other agents.
2. Concentrations of the successive alcohols necessary to produce a given stimulatory effect vary according to the following geometrical series: 1: a–1: a–2: a–3: a–4: . . . ., where a represents some real number.
3. Within certain limits the relationship between the logarithm of the concentration necessary to produce a given effect and the reciprocal of the reaction time is linear in the frog and in Planaria.
4. The concentration effect may be expressed by an equation which contains one constant characteristic of the alcohol series, and another one characteristic of each member. The ratio of the latter constants for successive alcohols represents a in the above series.
5. The stimulation by alcohols in these animals is considered to be due to energy changes at the receptive surfaces, brought about by a definite orientation of the respective alcohol molecules. Increase in stimulating efficiency as the number of CH2 groups increase must be due to the rôle of the non-polar portion of the alcohol molecule, since the polar group remains practically constant throughout the series.
6. In homologous series of organic compounds it is conceived that stimulating effects will be produced either by the polar group or the non-polar group, according to which one becomes dominant in effect, or to a combination of the two.
FACTORS INFLUENCING THE RESPIRATION OF ERYTHROCYTES
Authors: Wright G. Payling 
Published: May 2004

1. The oxygen consumption of normal and "primitive red cells" of fowls' blood has been determined at intervals in the course of an anemia produced by the injection of phenylhydrazine. The "primitive red cells" have an oxygen consumption at least twenty to twenty-five times greater than the normal red cells.
2. Suspension of the cells derived from the blood in anemia in sodium chloride solutions of various concentrations has comparatively little effect upon the oxygen consumption of the cells.
3. The red cells from anemic blood are sensitive to variations in the reaction of the medium in which they are suspended. The maximum oxygen consumption, after addition of a saline solution containing variable amounts of acid to the blood, took place at pH 7.75. They appeared somewhat more sensitive to variations on the acid side of this reaction than on the alkaline.
4. Addition of glucose to the medium increased the oxygen consumption of the cells. Their metabolism in a physiological saline solution containing 0.6 per cent of glucose was 15 per cent higher than in one in which no glucose was present.
5. Certain amino acids in low concentrations had little effect on oxygen consumption, though at higher concentrations some of them definitely diminished it.
FACTORS INFLUENCING THE RESPIRATION OF ERYTHROCYTES
Authors: Wright G. Payling 
Published: May 2004

1. The respiration of the reticulocytes of the rabbit has been measured during the period of an anemia produced by phenylhydrazine. Though the respiration increased greatly during the phase of regeneration, the oxygen consumption per billion reticulocytes throughout the period remained approximately the same.
2. The respiration of the reticulocytes was affected by changes in the reaction of the medium in which they were suspended, and was at its maximum about a pH of 8, with a probable intracorpuscular pH of about 7.75.
3. Variations in the tonicity of the suspending medium did not produce any great change in the respiration of the reticulocytes.
4. The presence of glycine, alanine, and glucose in the suspending medium resulted in no acceleration in the respiration of the cells. At higher concentrations glucose tended to depress the respiration. The material oxidized appears to be mainly or entirely contained in the corpuscles at the time they are liberated from the marrow.
5. A comparison is made of the respiration of the reticulated nucleated red cells present in the blood of anemic fowls and the non-nucleated reticulated red cells of rabbits. On the basis of equal volumes of cells, the respiration of the former is about twice that of the latter, while this in turn is about six times as great as the nucleated but non-reticulated normal red cells of the fowl.
THE EFFECT OF SALTS ON THE IONISATION OF GELATIN
Authors: Thimann Kenneth V. 
Published: May 2004

The effect of the addition of sodium chloride to gelatin solutions is shown from the Donnan relationship to increase the ionisation of the gelatin, the increase produced in acid solutions reaching a maximum at about 1/1000 molar salt concentration. This effect is attributed to the formation of complex ions.
From the similar action of calcium and copper chlorides the effective combining power of gelatin for complex positive ion formation is deduced. The bearing of complex ion formation on the zwitter-ionic structure and solubility phenomena of proteins is pointed out.
ELECTROMETRIC DETERMINATIONS OF THE DISSOCIATION OF GLYCOCOLL AND SIMPLE PEPTIDES1
Authors: Mitchell Philip H. , Greenstein Jesse P. 
Published: May 2004

1. The apparent acid and basic dissociation constants were determined potentiometrically by the methods of hydrolysis and of titration for the following ampholytes: Glycocoll, glycylglycocoll, alanylglycocoll, valylglycocoll, leucylglycocoll, methylleucylglycocoll, phenylalanylglycocoll and glycylglycylglycocoll. The constants were also determined in the presence of KCl and of K2SO4 at equal ionic strength.
2. In general, the relative order of magnitude of the constants decreased as the number of carbon atoms between amino and carboxyl groups increased. An explanation of this is offered on the basis of theories of electronic structure.
3. The application of the modern concepts of solutions to the case of the ampholytic ions is discussed. The inadequacy of the present theories is pointed out.
4. The constants were found, in general, to be functions of the hydrogen ion activity and the ionic strength of the solutions. Apparent contradictions to the Debye-Hückel theory are pointed out and partially explained on the basis of specific ion effects.