Effect Of Calcium Chloride Research Articles

Hydrodynamic properties and unperturbed dimensions of poly(gamma-hydroxy-L-proline) in aqueous solution.

Intrinsic viscosities and sedimentation coefficients have been measured as a function of molecular weight for poly(gamma-hydroxy-L-proline) in water. The molecular weight range covered is 9,000-35,000. High molecular weight poly(gamma-hydroxy-L-proline) in water has the hydrodynamic behavior of a random coil immersed in a good solvent, as judged by d ln [eta]/d ln M, d ln so/d ln M, dbeta/dM, and the size of beta[= nu rho (-1)]/1/3etaM-2/3(1 - nurho)-1]. The characteristic ratio, ((r2)o/nplp2) infinity, is found to be 15.9 +/- 1.6, which is not significantly different from the result of 13.7 +/- 0.9 obtained for poly(L-proline) by Mattice and Mandelkern under the same conditions. This observation casts doubt on the importance of intrachain hydrogen bonded bridges from the hydroxyl group to a carbonyl oxygen via a water molecule. The characteristic ratios and the effects of calcium chloride on the hydroynamic properties suggest that poly(L-proline) and poly(gamma-hydroxy-L-proline) possess a similar source of flexibility which is often overlooked. Two possibilities for this flexibility are a second energy minimum about the Calpha-C' bond and cis-trans isomerization about the peptide bond.

Calcium chloride effects on nuclear development in Tetrahymena.

SUMMARYConjugating pairs of syngen 1 exposed to 0·1 M-CaCl2during the time of macronuclear development often abort the new macronuclei and retain the old macronucleus and its associated phenotypes. The new micro-nucleus is retained, however, so that macro–micro heterocaryons can be constructed. Because the macronucleus is from a sexually mature strain, the heterocaryon is capable of mating immediately, without passing a period of sexual immaturity. Macronuclear abortion may prove a useful short-cut in genetic analysis.

Texture of cooked potatoes: Relationship between the compressive strength of cooked potato disks and release of pectic substances

AbstractIn experiments where the interaction of starch and cell size were kept to a minimum by taking identical material for each experiment (disks from the same tuber), the loss of compressive strength of potato tissue on cooking was found to be related to the release of pectic substances into the cooking liquor. This relationship was found to hold true whether large differences in compressive strength were produced by cooking the disks in water for varying lengths of time or by cooking disks in solutions of calcium or potassium chloride for fixed times. The release of starch into the cooking liquor was not related to loss of compressive strength when the results of a number of experiments from disks from the same tuber were compared.Increased cooking time, or the presence of potassium chloride in the cooking solution, reduced compressive strength and increased the amount of pectic substances released. The presence of calcium chloride had the reverse effect. It was not clear whether the effects of calcium chloride were due to calcium per se or the pH of the solutions after cooking, which were inversely related to calcium chloride concentration.

Nutritional Circulation in the Heart

The effect of a constant intracoronary infusion of potassium chloride and calcium chloride upon myocardial hemodynamics and clearance of 86Rubidium in the heart was studied in the isolated supported dog heart preparation (ISHP). In the ISHP with a constant coronary blood flow, potassium chloride in doses up to 4mg/min had no significant effect upon either the myocardial hemodynamics (MH), clearance of 86Rubidium (C86Rb) or the capillary transport coefficient, PS. Calcium chloride in small doses had no effect upon the MH, C86Rb or PS. A higher dose of calcium chloride (4mg/min) produced an increase in myocardial contractile force, left ventricular peak systolic pressure, myocardial oxygen consumption and a decrease in C86Rb and PS. Pretreatment of the ISHP with practolol (0.25mg/Kg), an agent which blocks adrenergic β-receptors, did not modify the effects of calcium chloride upon the MH, C86Rb or PS. It is concluded that the effects of calcium chloride are exerted directly, independent of a β-receptor mediation.

Effect of calcium chloride on the ternary liquid equilibria of the water-phosphoric acid-1-butanol system at 35.deg.C

Effect of calcium chloride on the ternary liquid equilibria of the water-phosphoric acid-1-butanol system at 35.deg.C

The effect of calcium chloride and formaldehyde on the release and composition of phospholipids from cryostat sections of rat hypothalamus.

Calcium chloride and formaldehyde inhibit the release of phospholipids from cryostat sections of rat hypothalamus into water. The effect of calcium chloride is thought to be due to the formation of complex coacervates between calcium and phospholipids. The inhibitory effect of formaldehyde may be caused by denaturation of proteins which are associated with phospholipids. Both calcium chloride and formaldehyde influence the composition of phospholipids remaining in the tissue and of those that are released into the medium. Calcium chloride and formaldehyde decrease the amount of phospholipids that can be extracted from the whole tissue by chloroform-methanol, 2:1.

The effects of calcium chloride and formaldehyde on the fatty acid composition of phosphatidyl choline from cryostat sections of rat hypothalamus.

Fixation of cryostat sections of rat hypothalamus in 4% formaldehyde + 1% calcium chloride for 11/2 hr influenced only slightly the fatty acid composition of phosphatidyl choline in the tissue and in the lipid fraction released into the medium. It was concluded that during this brief fixation period hardly any reaction occurs between formaldehyde and ethylenic double bonds in polar lipids.

In vitro degradation of oxalate and of cellulose by rumen ingesta from sheep fed Halogeton glomeratus.

The artificial rumen technique was used to study in vitro oxalate degradation and cellulose fermentation by rumen liquor obtained from a sheep before and after feeding IIalogeton glomeratus, an oxalate producing plant. Cellulose fermentation was inhibited when 240, 180, or 120 mg. of oxalate were added to 100 ml. of fermentation medium containing rumen liquor inoculum from a sheep that had not been fed halogeton. When 60 mg. of oxalate was added, the fermentation of cellulose was highly variable. When the inoculum for the in vitro fermentation was obtained from a sheep fed halogeton for three days, cellulose fermentation took place but at a slower rate and earlier in the fermentation period. Oxalate was degraded even when cellulose was not fermented. Degradation of oxalate did not take place until after four hours of fermentation when the rumen inoculum was taken from a sheep fed halogeton, but there was a delay of 8 hr. from rumen inoculum from the sheep not fed halogeton. Addition of calcium carbonate, calcium chloride, dicalcium phosphate, bonemeal or magnesium sulfate to the fermentation medium containing oxalate enhanced the fermentation of cellulose. The effect of calcium chloride was inverse to that of the other minerals. The in vitro data suggests that acute oxalate poisoning may involve impaired cellulose fermentation and rumen dysfunction.

Effect of calcium chloride on germination and pathogenicity of spores of Clostridium chauvoei

Effect of calcium chloride on germination and pathogenicity of spores of Clostridium chauvoei

Effect of calcium chloride and magnesium sulfate on the development of rigor mortis

In experiments on rats it was found that toxic doses of calcium chloride considerably accelerated, while magnesium sulfate inhibited, the development of rigor mortis. These effects are connected with the capacity of the calcium ion to disturb respiratory phosphorylation, and of the magnesium ions to promote it.

STREPTOMYCIN FORMATION BY INTACT MYCELIUM OF STREPTOMYCES GRISEUS.

Nomi, Ryosaku (Rutgers, The State University, New Brunswick, N.J.). Streptomycin formation by intact mycelium of Streptomyces griseus. J. Bacteriol. 86:1220-1230. 1963.-A study was made of streptomycin formation by intact mycelium of Streptomyces griseus 107 grown in glucose-yeast extract medium. When mycelium harvested after 24, 48, and 72 hr was compared, the earliest growth showed the highest activity in producing streptomycin from glucose. The concentration of streptomycin in the mycelium was higher in the older growth. Calcium chloride had a remarkable effect in increasing streptomycin production from the precursors in the mycelium, especially when the mycelium was grown for 48 hr or longer. The effect of calcium chloride cannot be attributed to the precipitation of an excess of inorganic phosphate in the medium. Glucose, fructose, glycerol, lactic acid, glucosamine, streptidine, and inositol stimulated streptomycin formation, whereas gluconic acid, glucuronic acid, streptamine, and strepturea did not. When 24-hr-old mycelium was suspended and shaken in 0.5% glucose solution, the antibiotic precursors necessary to produce streptomycin were found mainly in the supernatant of the culture rather than in the mycelium. The supernatant included some substance which had a weak antibiotic activity. This substance was less basic than streptomycin and was transformed to streptomycin with a remarkable increase in antibiotic activity.

Effect of calcium chloride on the durability of pre-tensioned wire in prestressed concrete

Summary This paper gives in the first place an account of investigations which were made to determine the extent to which calcium chloride may be present in the free state in concrete at various temperatures, since this will have a bearing on the extent of corrosion of embedded steel. It has been concluded that while there is a tendency for a large proportion of the added calcium chloride to react with the hydrating cement at normal temperatures, the residual small amount of free chloride always retained in solution will give an appreciable chloride concentration in solution and will cause a certain amount of corrosion of embedded steel. The amount of free chloride in solution is influenced by the composition of the cement, and will increase with an increase in the amount of calcium chloride added and with increasing temperature. These conclusions offer a reasonable interpretation of some of the findings of the second part of the paper which covers a direct study of corrosion of high-tensile steel embedded in different concretes containing calcium chloride. The present results indicate that with good concrete practice in mix design, depth of cover, and specification of materials, the additional corrosion induced by the use of flake calcium chloride up to about 2 % by weight of the cement in dense normally cured ordinary Portland cement concrete will have no structural significance. However, corrosion is greater under other conditions, and it appears that the degree of corrosion obtained in the presence of calcium chloride will depend on a number of factors, such as the quality of the concrete and adequacy of the casting procedures, the composition of the cement, the amount of calcium chloride added, the conditions of curing and storage of the concrete, and the diameter and initial surface condition of the steel wires.

STUDIES ON THE BIOLOGICAL CHARACTERISTICS OF MYCOBACTERIOPHAGES (I)

It has been reported previously by Groman et al. and Bobb et al. that the non ionic surface active agent, Tween 80, prevented the adsorption of Corynebacterium diphtheriae phage. Recently, Bowman and White et al. reported that Tween 80 prevented adsorption and multiplication in several mycobacteriophage-host systems but had no effect on free phage or adsorbed phage. These experiments were all originated from Tween 80 containing “Dubos medium”. The principal purpose in using Tween 80 for mycobacterial growth is to preparate the mycobacterial suspension without spontaneous clumps. By utilizing this characteristic of Tween 80, it is attempted to reveal the adsorption rate and the one step growth of mycobacteriophages But these attempts were not successful, because Tween 80 prevented the adsorption of mycobacteriophages to the host bacteria. In the author's previous paper (Kawahara), the results of an examination of physicochemical characteristics of mycobacteriophages A6, B1 and C3 were reported. In that paper, the effects of four kinds of surface active agents on adsorption and multiplication in Mycobacterium sp. Jucho-mycobacteriophage B1 system, the effects of them on free B1 phage and Jucho strain growth, and calcium chloride effects on adsorption in the same system which Adams and Kay et al. had already observed in the other systems, were reported. The object of this present study is to reveal host mycobacteria-mycobacteriophage relationships.

Effect of Calcium Chloride and Heat on Solutions of Mixtures of β-Lactoglobulin and Casein

Sumamry The effect of heat and calcium chloride concentration on the precipitation in the ultracentrifuge of casein and β -lactoglobulin has been studied. With β -lactoglobulin alone (1% solution) at pH 6.5 with 2m M calcium chloride per liter, the protein is totally precipitated after heating at 90° for 30min. and ultracentrifuging (127,000 X G for 45min.). With β -lactoglobulin (1%) and casein (2%) together under the same conditions, no precipitate is obtained until the calcium chloride concentration exceeds 4m M per liter. Electrophoretic examination of the supernatant solution, when 50% of the total protein is precipitated (8m M calcium chloride per liter), together with the insolubility of the precipitate in versene, suggested that the β -lactoglobulin is in the sediment. This conclusion was confirmed by the determination of the phosphorus to measure the casein distribution. Similar treatment of an unheated mixture showed that all of the β -lactoglobulin was in the supernatant solution. Also determined was the amount of calcium bound to the precipitated proteins, both alone and mixed. The total results support the assumption that the proteins in the mixture studied react independently and not as a complex.

The effect of calcium chloride on several α-chymotrypsin-catalyzed hydrolyses

The extent to which the reactivity of systems containing α-chymotrypsin and specific substrates of this enzyme may be enhanced by the presence of calcium chloride has been shown to be dependent not only upon the concentration of this salt but also upon the nature and/or concentration of several buffer components. An additional dependence upon the nature of the specific substrate has not been excluded.

An Accelerated Squeeze-Cementing Technique

Published in Petroleum Transactions, Volume 207, 1956, pages 25–29. Abstract A new cementing technique has been developed which is particularly applicable to permanent-type well completion operations. The technique makes use of the accelerating effect of calcium chloride on setting time and strength development of cement cake deposited in squeeze cementing. An unique feature is that the accelerator is applied after the unaccelerated cement slurry has been squeezed and the excess has been reversed from the well. Laboratory data on the accelerating effect of calcium chloride applied to the filter cakes of three low-water-loss cementing compositions demonstrate that the procedure results in relatively rapid development of strength and impermeability of the cement cake. Simulated squeeze-cementing tests made in the laboratory likewise corroborated the practicality of the procedure. The laboratory tests showed that a newly developed oil-emulsion cementing composition is more susceptible to acceleration of set than are modified cements containing high percentages of bentonite. The acceleration procedure has been used successfully in field operations. Introduction Nature of Problem In squeeze-cementing operations, a substantial amount of time is consumed in waiting on the cement to develop strength after it has been squeezed into the well. Frequently, an interval of 18 to 24 hours or longer is required for the development of strength sufficient to prevent failure of the cement during subsequent operations in the well. Reduction of this waiting-on-cement time offers appreciable savings both in time and in money. A particular type of squeeze-cementing operation to which an increasing amount of attention has been given is encountered in permanent-type well completion operations wherein perforations are to be squeezed off. In this procedure, it is customary to pump the cement slurry down the tubing and out into the perforated section through a retractable extension pipe. Squeeze pressure is then applied, which forces the cement slurry into the perforations and causes the build-up of a compact filter cake of cement within the perforations. The excess slurry remaining in the hole is then removed by reverse circulation. The extension pipe is then retracted, and, if a new interval is to be perforated, a perforating gun is run through the tubing. The newly perforated interval may then be tested by swabbing.

Effect of Calcium Chloride on the Preparation of Extracts of H. pertussis

Effect of Calcium Chloride on the Preparation of Extracts of <i>H. pertussis</i>

Effect of calcium chloride on concrete

Effect of calcium chloride on concrete

Effect of calcium chloride on portland cements and concretes

THE ADDITION OF CALCIUM CHLORIDE TO PORTLAND CEMENTS AND CONCRETES APPEARS TO INCREASE THE HEAT CONTRIBUTED AT THE END OF 24 HOURS BY DICALCIUM SILICATE AND TETRACALCIUM ALUMINO-FERRITE AND TO DECREASE THE HEAT CONTRIBUTED TO TRICALCIUM ALUMINATE. CALCIUM CHLORIDE HAS LITTLE EFFECT ON THE HEAT CONTRIBUTED BY TRICALCIUM SILICATE. CALCIUM CHLORIDE INCREASES THE RATE AT WHICH THE HEAT IS EVOLVED FROM ALL CEMENTS. THE STRENGTH CONTRIBUTED BY THE TWO SILICATE COMPOUNDS IN CEMENT WERE INCREASED AND THE STRENGTH CONTRIBUTED BY TRICALCIUM ALUMINATE WAS DECREASED BY THE ADDITION OF CALCIUM CHLORIDE. CALCIUM CHLORIDE DECREASED THE TIME OF SET OF ELEVEN COMMERCIAL CEMENTS AND INCREASED THE FLOW AND THE STRENGTH OF THE RESULTING CONCRETE. THE PHYSICAL PROPERTIES OF THE EXPERIMENTAL CEMENTS WERE SIMILARLY AFFECTED BY THE ADDITION OF CALCIUM CHLORIDE. THE OPTIMUM AMOUNTS TO BE ADDED FOR DIFFERENT TYPES OF CEMENT AND AT VARIOUS CURING TEMPERATURES ARE INDICATED. /AUTHOR/

Some metabolic aspects of calcium therapy.

Excretion of the various mineral elements was followed for a period of ten days after a diet of known inorganic composition. During the last four days of the experiment a measured amount of calcium acetate was taken by mouth. Balance sheets, for the four day period of calcium acetate and the four day period preceding, show that calcium has no effect on the metabolism of any element except phosphorus. There was no increase in the excretion of sodium as after the administration of potassium salts. The amount of phosphorus excreted in the urine was decreased and the amount excreted in the feces was increased during the calcium acetate period. With this decrease in the phosphoric acid load on the kidney the amount of ammonia excreted in the urine was also decreased. In another experiment similarly conducted, it was found that the administration of potassium or magnesium acetates had no influence on the partititon of phosphorus in the urine and feces, whereas the effect of calcium chloride was similar to that of calcium acetate.