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THE OPTIMUM HYDROGEN ION CONCENTRATION FOR THE GROWTH OF PNEUMOCOCCUS

Dernby, K. G.; Avery, O. T.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/09/1918 EN
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66.05%
1. The optimum hydrogen ion concentration for the growth of the various types of pneumococcus is a pH of about 7.8. 2. The limiting hydrogen ion concentrations for the growth of pneumococcus are a pH of 7.0 and a pH of 8.3. 3. Phosphates used in adjusting reactions of media retard growth if present in a concentration greater than 0.1 molecular. 4. Culture media for pneumococci should, therefore, have an initial reaction between a pH of 7.8 and 8.0 and a total salt concentration not exceeding 0.1 M.

THE USE OF THE FINAL HYDROGEN ION CONCENTRATION IN DIFFERENTIATION OF STREPTOCOCCUS HÆMOLYTICUS OF HUMAN AND BOVINE TYPES

Avery, Oswald T.; Cullen, Glenn E.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 31/01/1919 EN
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66.1%
1. Under the conditions of these experiments, there appears to be a distinct and constant difference in the final hydrogen ion concentration of Streptococcus hæmolyticus from human and bovine sources. 2. Of 124 strains of Streptococcus hæmolyticus from known human origin, 116 reached a final hydrogen ion concentration of from pH 5.0 to 5.3. Only 8 reached a pH more acid than 5.0 and none more acid than pH 4.8. 3. Of 45 strains of Streptococcus hæmolyticus from bovine sources, including 26 strains isolated from milk and the udder of cows, and 19 from cream cheese, 40 reached a final hydrogen ion concentration of pH 4.3 to 4.5. Of the remaining 5 which reached a pH of 5.0 to 5.2, two were of known human type and three of uncertain diagnosis. 4. A rapid and practical application of this method is proposed as a presumptive test in the differentiation of human and bovine types of Streptococcus hæmolyticus.

THE RELATION OF PROTEOLYTIC ENZYMES IN THE PNEUMONIC LUNG TO HYDROGEN ION CONCENTRATION. AN EXPLANATION OF RESOLUTION

Lord, Frederick T.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/10/1919 EN
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66.17%
Evidence is given of the presence in the cellular material obtained from the pneumonic lung of a proteolytic enzyme digesting coagulated blood serum at hydrogen ion concentrations of 7.3 to 6.7 and inactive at higher; i.e., more acid concentrations. In addition, evidence is brought forward of the presence in the cellular material from the pneumonic lung of a proteolytic enzyme splitting peptone to amino-acid nitrogen. This enzyme is operative at hydrogen ion concentrations from 8.0 to 4.8, but most active at 6.3 or 5.2. These findings may be regarded as having a bearing on resolution in pneumonia. During the course of the disease a gradual increase in the hydrogen ion concentration of the exudate probably takes place. With the breaking down of cellular material an enzyme digesting protein (fibrin) in weakly alkaline and weakly acid media may be liberated. With a gradual increase in the hydrogen ion concentration of the pneumonic lung the action of this enzyme probably ceases. An enzyme capable of splitting peptone to amino-acid nitrogen is probably active during the proteolysis of the fibrin and further activated when the hydrogen ion concentration of the pneumonic lung is increased to within its range of optimum activity at a pH of 6.3 and 5.2. By this means it may be conceived that the exudate is dissolved and resolution takes place.

THE RELATION OF THE PNEUMOCOCCUS TO HYDROGEN ION CONCENTRATION, ACID DEATH-POINT, AND DISSOLUTION OF THE ORGANISM

Lord, Frederick T.; Nye, Robert N.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/10/1919 EN
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66.17%
1. In the growth and death of the pneumococcus in fluid media containing 1 per cent glucose the production of acid is the most important bactericidal factor. 2. 1 per cent glucose bouillon cultures of the pneumococcus allowed to grow and die out usually reach a final acidity of a pH of about 5.1. 3. At a hydrogen ion concentration of about 5.1 or higher, the pneumococcus does not survive longer than a few hours. 4. In hydrogen ion concentrations of about 6.8 to 7.4 the pneumococcus may live for at least many days. 5. In the intervening hydrogen ion concentrations, between 6.8 and 5.1, the pneumococcus is usually killed with a rapidity which bears a direct relation to the hydrogen ion concentration; i.e., the greater the acidity the more rapid is the death. 6. Cloudy suspensions of washed pneumococci in hydrogen ion concentrations varying from 8.0 to 4.0 show, after incubation, dissolution of organisms in lower hydrogen ion concentrations than about 5.0. This dissolution is most marked at about 5.0 to 6.0. Some dissolution also takes place toward the more alkaline end of the scale. No dissolution occurs at the most acid end of the scale.

GROWTH OF FIBROBLASTS AND HYDROGEN ION CONCENTRATION OF THE MEDIUM

Fischer, Albert
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 31/10/1921 EN
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66.08%
1. The rate of growth of fibroblasts is markedly modified by slight changes in the hydrogen ion concentration of the medium. The curves expressing the rate of growth in function of the hydrogen ion concentration of the medium are nearly symmetrical on both sides of the maximum. 2. The optimum growth of fibroblasts occurs at pH 7.4 to 7.8. A slight change from this reaction has a remarkable influence on the rate of growth. 3. Fibroblasts show more resistance to higher alkalinity than to higher acidity. They grew for only four to six generations in a medium having a pH of 5.5, and for more than ten generations in one of 8.5. 4. The influence of different hydrogen ion concentrations on fibroblasts was only of a quantitative nature.

INFLUENCE OF TEMPERATURE AND HYDROGEN ION CONCENTRATION UPON THE SPORE CYCLE OF BACILLUS SUBTILIS

Itano, Arao; Neill, James
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/03/1919 EN
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66.02%
1. At 5°C. no germination took place. 2. At 25°C. and at 37°C. germination occurs if the hydrogen ion concentration of the broth is kept between pH 5 and pH 10, but not at higher or lower pH values. 3. The completion of the spore cycle likewise requires a hydrogen ion concentration between pH 5 and pH 10. 4. The spores can germinate when the pH value is 10, although after germination the vegetative cells multiply only to a very slight extent and soon pass into spores. 5. The slight growth and multiplication of vegetative cells in broth of pH 10 suggest that the formation of endospores in this medium must be caused largely by the unfavorable reaction of the medium rather than by the accumulation of metabolic products. 6. Automatic adjustment of the medium seems to play a rôle in the completion of the spore cycle. 7. The results are not only of theoretical importance but they have a practical application to the preservation of food by canning and by other methods.

THE INFLUENCE OF HYDROGEN ION CONCENTRATION ON THE INACTIVATION OF PEPSIN SOLUTIONS

Northrop, John H.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/05/1920 EN
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66.19%
1. Pepsin in solution at 38°C. is most stable at a hydrogen ion concentration of about 10–5 (pH 5.0). 2. Increasing the hydrogen ion concentration above pH 5.0 causes a slow increase in the rate of destruction of pepsin. 3. Decreasing the hydrogen ion concentration below pH 5.0 causes a very rapid increase in the rate of destruction of the enzyme. 4. Neither the purity of the enzyme solution nor the anion of the acid used has any marked effect on the rate of destruction or on the zone of hydrogen ion concentration in which the enzyme is most stable. 5. The existence of an optimum range of hydrogen ion concentration for the digestion of proteins by pepsin cannot be explained by the destruction of the enzyme by either too weak or too strong acid.

THE PHYSIOLOGY OF THE RESPIRATION OF FISHES IN RELATION TO THE HYDROGEN ION CONCENTRATION OF THE MEDIUM

Powers, Edwin B.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/01/1922 EN
Relevância na Pesquisa
66.16%
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.

REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH

Irving, Laurence
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/11/1926 EN
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66.02%
The normal reaction of the cœlomic fluid in Patiria miniata and Asterias ochraceus is pH 7.6, and of the cæca, 6.7, compared with sea water at 8.3, all without salt error correction. A medium at pH 6.7–7.0 is optimum for the cæca for ciliary survival and digestion of protein, and is maintained by carbon dioxide production. The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It does not represent an elimination gradient for carbon dioxide. Because the normal excised cæca maintain a definite hydrogen ion concentration and change their internal environment toward that as an optimum during life, there exists a regulatory process which is an important vital function.

THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS : I. INCREASED HYDROGEN ION CONCENTRATION AND THE INTENSITY OF MUTUAL INDUCTIONS BY NEIGHBORING EGGS OF FUCUS FURCATUS

Whitaker, D. M.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/01/1937 EN
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66.1%
1. The eggs of Fucus furcatus develop perfectly in sea water acidified to pH 6.0. They are retarded at pH 5.5. At pH 5.0 they do not develop, nor do they cytolize. 2. In normal sea water in the dark at 15°C., eggs develop rhizoids on the sides in the resultant direction of a mass of neighboring eggs. The polarity and the whole developmental pattern of the embryo is thereby induced. This inductive effect does not operate, however, unless the directing mass is an appreciable aggregation of cells (10 or more), or unless there are numerous other eggs in the dish. A group of five eggs alone in a dish do not carry out mutual inductions. Two eggs alone in a dish do not develop rhizoids toward each other. 3. When the sea water is acidified to pH 6.0 all sizes of aggregations carry out mutual inductions. Two eggs alone in a dish now develop rhizoids on the sides toward each other, provided they are not more than about 4 egg diameters apart. 4. Increased hydrogen ion concentration thus augments or intensifies the mutual inductive effect. 5. This may explain why only larger masses of eggs show inductions in normal sea water, since presumably the larger masses considerably increase the hydrogen ion concentration locally. 6. The nature of the inductive action is discussed. 7. In acidified sea water at pH 6.0...

THE EFFECT OF HYDROGEN ION CONCENTRATION UPON THE INDUCTION OF POLARITY IN FUCUS EGGS : III. GRADIENTS OF HYDROGEN ION CONCENTRATION

Whitaker, D. M.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/07/1938 EN
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66.19%
1. Gradients of hydrogen ion concentration across Fucus eggs growing in sea water determine the developmental polarity of the embryo. 2. Gradients may determine polarity even if removed before the morphological response begins. 3. The rhizoid forms on the acid side of the egg unless this is too acid, in which case it develops on the basic side of the egg. 4. Since gradients of hydrogen ion concentration in sea water produce gradients of CO2 tension, as a result of chemical action on the carbonate buffer system, it is not proven whether the physiological effects are due to the hydrogen ions, or to the CO2 which they produce in the medium. 5. The developmental response of the eggs to gradients of hydrogen ion (or CO2) concentration provides an adequate but not an exclusive explanation of the group effect in Fucus. 6. Hydrogen ions may exert their effect by activating growth substance. Hydrogen ions or CO2 probably also affect the underlying rhizoid forming processes in other ways as well.

THE EFFECTS OF HYDROGEN ION CONCENTRATION UPON THE METAMORPHIC PATTERN OF THYROXIN- AND IODINE-TREATED TADPOLES

Marzulli, Francis N.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/03/1942 EN
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66.34%
1. It has been shown quantitatively that the degree of response of the hind limbs of tadpoles to the action of thyroxin is dependent upon the lengths of the limbs at the beginning of treatment. 2. Both the potency of the inducing substance and the rate of penetration of the substance into the animal might be involved in the effects of hydrogen ion concentration on induced development. 3. Changes in hydrogen ion concentration affect the inducing power of thyroxin and iodine differently. With thyroxin, it is the rate of penetration of the molecule which determines the amount of growth, but with iodine it is the chemical form in which the substance has entered the animal which is of prime importance. 4. The hydrogen ion concentration of thyroxin solutions does not affect their potency when they are injected into tadpoles. 5. Change in hydrogen ion concentration of the environment does not affect the potency of thyroxin injected into tadpoles. 6. When thyroxin is administered in the environmental solution its effects, as measured by increase in hind limb length are greater at higher than at lower hydrogen ion concentrations in the range tested. 7. Since the potency of thyroxin is unaffected by change in hydrogen ion concentration when the thyroxin solution is injected...

PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XIV. THE HYDROGEN ION CONCENTRATION OF THE BLOOD OF CHICKEN EMBRYOS AS A FUNCTION OF TIME.

Cohn, A. E.; Mirsky, A. E.;
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/01/1929 EN
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66.02%
We have studied by means of glass electrodes the hydrogen ion concentration of the blood of chicken embryos from 8 to 20 days. When plotted as a curve, the average data show that a constant change takes place in the measurement, being acid at the beginning of this period and becoming alkaline toward its end. The acid reaction we think was characteristic not only of the embryos of fowl, but of the fetuses of cats and indeed as Warburg has shown of rapidly growing tissue in general. We have suggested the possibility, though we have no data to substantiate the suggestion, that the hydrogen ion concentration may under conditions like these, seeing that the curve of change resembles that of oxygen consumption, be expressive of changes in the rate of metabolism.

THE BACTERICIDAL ACTION OF HUMAN SERUM ON HEMOLYTIC STREPTOCOCCI : III. STUDIES CONCERNING: (1) THE SIGNIFICANCE OF HYDROGEN ION CONCENTRATION IN RELATION TO THE STREPTOCOCCIDAL ACTION OF SERUM; (2) THE EFFECT OF REDUCING AGENTS ON THE PHENOMENON

Tillett, William S.; Stock, C. Chester
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 31/10/1937 EN
Relevância na Pesquisa
66.02%
Aerobic Tests. Changes in pH Which Occurred during Incubation.—(a) The pH of sterile specimens of both normal and patients' sera increased, during 24 hours incubation, from 8.0–8.8 up to 9.2–9.6. (b) The pH of patients' sera, inoculated with hemolytic streptococci, progressed in the alkaline direction as did the sterile specimens. (c) The pH of normal sera, inoculated with hemolytic streptococci, pursued a variable course at lower levels than the sterile specimens. The differences in the changes in pH which occurred in streptococcidal sera and in normal controls were dependent upon and secondary to the presence or absence of killing action in the specimens. Aerobic Tests. Effect of Different Levels of Hydrogen Ion Concentration, Adjusted at Beginning of Experiment, but Uncontrolled during Period of Incubation.—(a) The streptococcidal activity of patients' sera was inactivated when the hydrogen ion concentration of the specimens was adjusted to levels ranging from 6.4 to 7.4. The inactivation of highly potent samples of sera required a greater reduction in pH than did specimens of moderate killing activity. (b) Normal sera, adjusted to pH 9.2 or higher, exhibited a relatively slowly acting bactericidal process, which seemed to represent the toxic effect of alkalinity. Aerobic Tests. Effect of Glutathione and Sodium Ascorbate.—The streptococcidal action of patients' sera was markedly impaired by the addition of reducing agents. The inactivation was...

AMPHOTERIC COLLOIDS : I. CHEMICAL INFLUENCE OF THE HYDROGEN ION CONCENTRATION.

Loeb, Jacques
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/09/1918 EN
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66.05%
1. It has been shown in this paper that while non-ionized gelatin may exist in gelatin solutions on both sides of the isoelectric point (which lies for gelatin at a hydrogen ion concentration of CH = 2.10–5 or pH = 4.7), gelatin, when it ionizes, can only exist as an anion on the less acid side of its isoelectric point (pH > 4.7), as a cation only on the more acid side of its isoelectric point (pH < 4.7). At the isoelectric point gelatin can dissociate practically neither as anion nor as cation. 2. When gelatin has been transformed into sodium gelatinate by treating it for some time with M/32 NaOH, and when it is subsequently treated with HCl, the gelatin shows on the more acid side of the isoelectric point effects of the acid treatment only; while the effects of the alkali treatment disappear completely, showing that the negative gelatin ions formed by the previous treatment with alkali can no longer exist in a solution with a pH < 4.7. When gelatin is first treated with acid and afterwards with alkali on the alkaline side of the isoelectric point only the effects of the alkali treatment are noticeable. 3. On the acid side of the isoelectric point amphoteric electrolytes can only combine with the anions of neutral salts, on the less acid side of their isoelectric point only with cations; and at the isoelectric point neither with the anion nor cation of a neutral salt. This harmonizes with the statement made in the first paragraph...

HYDROGEN ION CONCENTRATION OF CULTURES OF PNEUMOCOCCI OF THE DIFFERENT TYPES IN CARBOHYDRATE MEDIA

Avery, O. T.; Cullen, Glenn E.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/10/1919 EN
Relevância na Pesquisa
66.16%
1. The optimum hydrogen ion concentration for growth of pneumococcus is pH 7.8. 2. In broth cultures growth of pneumococcus continues until a final hydrogen ion concentration of about pH 5.0 is reached, if sufficient fermentable carbohydrate' (above 0.4 per cent) is present. Apparently this acidity is sufficient in itself to stop growth. 3. If less carbohydrate is present in the medium growth ceases at a lower hydrogen ion concentration, apparently because of exhaustion of carbohydrate. If no carbohydrate is present save that extracted from the meat of which the broth is made (plain broth medium), growth initiated at pH 7.8 (optimum reaction) ceases at about pH 7.0. 4. If bacteria-free filtrates of plain broth cultures in which growth has ceased are readjusted to pH 7.8 and reinoculated with pneumococcus, no growth occurs unless carbohydrate is added. However, if bacteria-free filtrates of dextrose broth cultures in which growth has ceased (pH 5) are readjusted to pH 7.8 and reinoculated with pneumococcus growth occurs. 5. Cultures of pneumococcus with all the carbohydrates which were fermentable under the conditions used, namely maltose, saccharose, lactose, galactose, raffinose, dextrose, and inulin, gave identical results in the rate of reaction change...

HYDROGEN ION CONCENTRATION IN EXUDATES OF PNEUMOCOCCUS INFECTION

Kelley, William H.; Scadron, E. N.; Shinners, B. M.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 30/04/1938 EN
Relevância na Pesquisa
66.17%
The hydrogen ion concentration in the lesions of experimental pneumococcus infection has been estimated directly by pH determinations on exudates from living animals. For indirect evidence of an increase in hydrogen ion concentration within the lesions, the difference in sugar content between exudate and blood from animals with pneumococcus infection has been measured. With sanguinous exudate from the consolidated lungs of dogs with experimental pneumococcus pneumonia, the findings were not always consistent, but usually there was either direct or indirect evidence of increased hydrogen ion concentration. The physicochemical changes in exudate from animals treated with artificial pneumothorax showed no important differences from those in other specimens. In concurrence with Lord's (1, 2) observation of increased acidity in pneumonia exudate obtained at autopsy, sugar concentrations, which are low in the blood, were markedly reduced in exudates from animals which had died of the infection. Serous exudates from dermal pneumococcus infection in rabbits uniformly showed definite acidity by both direct and indirect methods of estimation. The hydrogen ion concentrations in exudate from dermal pneumococcus infection in rabbits varied between pH 6.87 and 6.66 but were not always proportional to the difference in sugar concentrations between the exudate and blood. While these hydrogen ion concentrations are similar to those attained in the pneumonic exudate from dogs...

THE SIGNIFICANCE OF THE HYDROGEN ION CONCENTRATION FOR THE DIGESTION OF PROTEINS BY PEPSIN

Northrop, John H.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 20/11/1920 EN
Relevância na Pesquisa
66.3%
The experiments described above show that the rate of digestion and the conductivity of protein solutions are very closely parallel. If the isoelectric point of a protein is at a lower hydrogen ion concentration than that of another, the conductivity and also the rate of digestion of the first protein extends further to the alkaline side. The optimum hydrogen ion concentration for the rate of digestion and the degree of ionization (conductivity) of gelatin solutions is the same, and the curves for the ionization and rate of digestion as plotted against the pH are nearly parallel throughout. The addition of a salt with the same anion as the acid to a solution of protein already containing the optimum amount of the acid has the same depressing effect on the digestion as has the addition of the equivalent amount of acid. These facts are in quantitative agreement with the hypothesis that the determining factor in the digestion of proteins by pepsin is the amount of ionized protein present in the solution. It was shown in a previous paper that this would also account for the peculiar relation between the rate of digestion and the concentration of protein. The amount of ionized protein in the solution depends on the amount of salt formed between the protein (a weak base) and the acid. This quantity...

The enzymatic synthesis of protein. III. The effect of the hydrogen ion concentration on peptic synthesis

Wasteneys, Hardolph; Borsook, Henry
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em /01/1925
Relevância na Pesquisa
66.1%
In two previous communications the authors have described a synthesis of protein by pepsin in a concentrated peptic hydrolysate of albumin (1); and the effect of temperature on this synthesis (2). The justification for describing the synthetic product as protein is discussed in our previous paper (2). In these communications the optimum hydrogen ion concentration was stated to be pH 4.0; but the influence of the hydrogen ion concentration was otherwise not discussed. The importance of the degree of acidity was realized early by Sawjalow (3), who did not, however, define it precisely, and by Henriques and Gjaldbäk (4), who gave the optimum pH as 1.5. This hydrogen ion concentration in our experience, despite the existence of all other optimum conditions, allows only very small amounts of synthesis. Either Henriques and Gjaldbäk were in error, or the occurrence of the optimum pH at 1.5 was due to some as yet unrecognized factor.

DLTS of low-energy hydrogen ion implanted in n-Si

Deenapanray, Prakash
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66%
We have used deep level transient spectroscopy and capacitance-voltage measurements to study the influence of low-energy hydrogen ion implantation on the creation of defects in n-Si. In particular, we have studied the ion fluence dependence of the free carrier compensation at room temperature, and we have measured the generation of VO-H complex and VP-pair in ion implanted samples. The 7.5 keV H ions created defects in the top 0.3 μm of samples, which resulted in carrier compensation to depths exceeding 1 μm. This effect is not due to defects created by ion channeling but is rather due to the migration of defects as demonstrated using binary collision code MARLOWE.