Increasing CaCl2 Concentration Research Articles

Surface Tensions of Molten Binary CaCl2-NaCl, LaCl3-NaCl, and LaCl3-CaCl2 and Ternary LaCl3-CaCI2-NaCl Systems

The surface tensions of the molten binaries CaCl2-NaCl, LaCl3-NaCl, and LaCl3-CaCl2 and the three quasi-binaries LaCl3-nNaCl.mCaCl2 (mole ratios n : m = 2.7 : 1, 1 : 1, and 1 : 3.1) were measured by the maximum bubble pressure method. The surface tension of CaCl2-NaCl and LaCl3-CaCl2 increases curvilinearly with increasing CaCl2 concentration, while below 900 °C the isotherms of LaCl3-NaCl show a minimum at ca. 30 mol% LaCl3. A minimum was also observed for the quasi-binary with n : m = 2.7 : 1. The surface tensions for the ternary LaCl3-CaCl2-NaCl at 900 °C were constructed from the above results.

Monoclonal antibodies against human abnormal (des-gamma-carboxy)prothrombin specific for the calcium-free conformer of prothrombin.

A monoclonal antibody JO1 X 1 was prepared against human abnormal prothrombin using the hybridoma technique. The clone secreting this antibody was selected on the basis of the ability of this antibody to bind to abnormal prothrombin, but not to prothrombin, in the presence of calcium ions. The antibodies were purified by affinity chromatography in EDTA on columns of prothrombin-Sepharose. Bound antibodies were eluted with 15 mM CaCl2. The kinetics of dissociation of antibody from the antibody-prothrombin complex with the addition of calcium ions fit a first-order kinetic model. Increasing CaCl2 concentration increased the rate of antibody-prothrombin dissociation. Ca(II) and Mn(II) inhibited antibody-prothrombin interaction; half-maximal binding was observed at 0.9 and 4 mM, respectively. Mg(II) had little effect on antibody-antigen interaction. The JO1 X 1 antibody bound fragment 1, fragment (1-39), abnormal prothrombin, and prothrombin equivalently in the presence of EDTA, but did not bind to des(1-44)prothrombin in the presence of EDTA or prothrombin in the presence of CaCl2. These results indicate that the monoclonal antibody JO1 X 1 is conformation specific for the calcium-free conformer of prothrombin and directed against an antigenic determinant near the NH2 terminus of prothrombin expressed in the 1-39 region of the protein. This analysis provides confirmation of the presence of a metal-free conformer of prothrombin.

Effect of calcium chloride on the growth and ethanol production by free cells of Zymomonas mobilis

The effect of calcium chloride concentration on the growth rate and ethanol production using free cells of Zymomonas mobilis was studied. There was no appreciable change in rates of cell mass production and ethanol formation in the medium containing upto 2g/L CaCl2. On further increase in CaCl2 concentration, the rates started decreasing. However, the ethanol yield decreased and biomass yield increased with increase in CaCl2 concentration.

The actions of sodium nitroprusside and diltiazem on calcium-, potassium- and histamine-induced contractile responses in isolated rabbit basilar artery, aorta, taenia coli and tracheal smooth muscle.

The effects of sodium nitroprusside (NaNP) and diltiazem on CaCl2-,KCl- and histamine-induced contractile responses were studied in isolated rabbit basilar artery, aorta, taenia coli and trachea. NaNP reduced CaCl2-induced maximal contractions in basilar artery and aorta, but little affected those in taenia coli and trachea. NaNP reduced histamine-induced maximal contraction markedly in aorta but slightly in basilar artery and taenia coli. The reduction in aorta was reversed by increasing CaCl2 contraction in bathing medium. NaNP inhibited histamine-induced contractions of basilar artery, aorta and taenia coli in Ca-free medium. Diltiazem reduced CaCl2-induced maximal contractions in basilar artery and aorta, whilst it caused a parallel shift of concentration-response curves for CaCl2 to the right in taenia coli and trachea. diltiazem reduced histamine-induced maximal contractions in basilar artery and taenia coli. These reductions were reversed by increasing CaCl2 concentration in bathing medium. Diltiazem strongly inhibited histamine-induced contraction of taenia coli in Ca-free medium. The effects of NaNP and diltiazem on KCl-induced contractions both in normal (Ca; 2.5 mM) and in high Ca (Ca; 12.5 mM) media were also studied. From the results obtained in this study, the actions of NaNP and diltiazem were considered to vary with the type of smooth muscle or the condition eliciting contraction. Their possible mechanisms were discussed in this paper.

The actions of D 600, aspaminol and papaverine on calcium-, potassium- and histamine-induced contractions of isolated rabbit basilar artery, aorta, taenia coli and tracheal smooth muscle.

The effects of D 600, Aspaminol (1,1-diphenyl-3-piperidinobutanol hydrochloride) and papaverine on CaCl2-, KCl- and histamine-induced contractile responses of isolated rabbit basilar artery, aorta, taenia coli and tracheal smooth muscle were compared with each other. D 600 reduced CaCl2-induced maximal responses in basilar artery and aorta, and parallelly shifted the concentration-response curves for CaCl2 to the right in taenia coli and trachea. D 600 also reduced histamine-induced maximal contractions in basilar artery and taenia coli. These reductions were not reversed by increasing CaCl2 concentration in bathing fluids. High concentration of D 600 parallelly shifted the concentration-response curve for histamine to the right in aorta. Like D 600, Aspaminol, a nonspecific smooth muscle relaxant, parallelly shifted the concentration-response curve for histamine in aorta. Papaverine parallelly shifted the concentration-response curve for CaCl2 in taenia coli and reduced the maximal responses in other tissues. Papaverine also reduced histamine-induced maximal responses in basilar artery, aorta and taenia coli. Influences of these smooth muscle relaxants on histamine-induced contraction in Ca-free buffer solution and on KCl-induced contraction in normal and high Ca (Ca: 12.5 mM) buffer solution were also studied. From the results obtained in this study, the effects of smooth muscle relaxants are considered to vary with the type of smooth muscle or the condition eliciting contraction, and the possible mechanisms of the contractions were discussed.

THE ACTIONS OF D 600, ASPAMINOL AND PAPAVERINE ON CALCIUM-, POTASSIUM- AND HISTAMINE-INDUCED CONTRACTIONS OF ISOLATED RABBIT BASILAR ARTERY, AORTA, TAENIA COLI AND TRACHEAL SMOOTH MUSCLE

The effects of D 600, Aspaminol (1,1-diphenyl-3-piperidinobutanol hydrochloride) and papaverine on CaCl2-, KCl- and histamine-induced contractile responses of isolated rabbit basilar artery, aorta, taenia coli and tracheal smooth muscle were compared with each other. D 600 reduced CaCl2-induced maximal responses in basilar artery and aorta, and parallelly shifted the concentration-response curves for CaCl2 to the right in taenia coli and trachea. D 600 also reduced histamine-induced maximal contractions in basilar artery and taenia coli. These reductions were not reversed by increasing CaCl2 concentration in bathing fluids. High concentration of D 600 parallelly shifted the concentration-response curve for histamine to the right in aorta. Like D 600, Aspaminol, a nonspecific smooth muscle relaxant, parallelly shifted the concentration-response curve for histamine in aorta. Papaverine parallelly shifted the concentration-response curve for CaCl2 in taenia coli and reduced the maximal responses in other tissues. Papaverine also reduced histamine-induced maximal responses in basilar artery, aorta and taenia coli. Influences of these smooth muscle relaxants on histamine-induced contraction in Ca-free buffer solution and on KCI-induced contraction in normal and high Ca (Ca: 12.5 mM) buffer solution were also studied. From the results obtained in this study, the effects of smooth muscle relaxants are considered to vary with the type of smooth muscle or the condition eliciting contraction, and the possible mechanisms of the contractions were discussed.

Interaction of 11S Fraction of Soybean Protein with Calcium Ion

In order to clarify the interaction of the 11S fraction of soybean proteins with calcium ion, the volume change associated with the interaction was measured with a dilatometer. When CaCl2 was added to 11S protein solution, there appeared a volume increase to a constant saturated value with increasing CaCl2 concentration. Then, the volume decreased at the concentration above 0.04 m CaCl2. On the other hand, the binding of calcium ion to 11S protein was determined by gel filtration at pH 6.0, 7.0 and 8.0. The number of Ca2+ ion bound to 11S protein was evaluated to be 4 to 11 depending on CaCl2 concentration in 0.02 m Tris-HCl and 0.18 m KCl solution at pH 8.0. However, the binding was not observed at pH 6.0 and 7.0 By CD measurements it was shown that the addition of 0.05 m CaCl2 to the protein solution did not cause any change in the secondary structure of the protein molecules.

Nature of interaction of dextran sulfate with lecithin dispersions and lysolecithin micelles.

Lecithin and lecithin/cholesterol dispersions as well as lysolecithin micelles were used to provide basic information on the mechanism of the interaction of zwitterionic phospholipids with dextran sulfate. The addition of dextran sulfate to lecithin dispersions or lysolecithin micelles in the presence of Ca2+ produced insoluble complexes. At each Ca2+ concentration, the amount of insoluble complex formed was maximal at the equivalence dextran sulfate/phospholipid weight ratio. An increase in CaCl2 concentration up to 10 mM progressively increased the equivalence ratios for the phospholipids. Further increase in Ca2+ concentration did not influence the equivalence ratio for maximal complex formation. The conversion of lecithin dispersions into insoluble complexes was very effective even at low Ca2+ concentrations. Approximately 70% of the lecithin was converted to the insoluble complex at CaCl2 concentrations as low as 0.5 mM and the complete conversion was observed at CaCl2 concentrations above 2.5 mM. In the presence of cholesterol, the precipitation curve for insoluble complex formation became broader than that of lecithin alone, indicating the enhancing effect of cholesterol on the insoluble complex formation both below and above the equivalence ratio. The stoichiometry of the interaction of the zwitterionic phospholipids with dextran sulfate inthe presence of calcium was determined using lysolecithin micelles. At the CaCl2 concentrations above 20 mM, the insoluble complex possessed a ratio of lysolecithin/calcium/sulfate group of approximately 2/1/3 (mol/mol/mol). It appears that the formation of the insoluble complex of lecithin or lysolecithin with dextran sulfate represents the mutually enhancing interactions involving both positive and negative charges of the zwitterionic phospholipids. These are the direct electro static interaction between the phospholipid choline nitrogen and the sulfate groups of dextran sulfate and the calcium cross-linking of the phosphate groups to the sulfate groups or to the phosphate groups of neighboring phospholipids.

Interaction of 11S fraction of soybean protein with calcium ion.

In order to clarify the interaction of the 11S fraction of soybean proteins with calcium ion, the volume change associated with the interaction was measured with a dilatometer. When CaCl2 was added to 11S protein solution, there appeared a volume increase to a constant saturated value with increasing CaCl2 concentration. Then, the volume decreased at the concentration above 0.04 m CaCl2. On the other hand, the binding of calcium ion to 11S protein was determined by gel filtration at pH 6.0, 7.0 and 8.0. The number of Ca2+ ion bound to 11S protein was evaluated to be 4 to 11 depending on CaCl2 concentration in 0.02 m Tris-HCl and 0.18 m KCl solution at pH 8.0. However, the binding was not observed at pH 6.0 and 7.0 By CD measurements it was shown that the addition of 0.05 m CaCl2 to the protein solution did not cause any change in the secondary structure of the protein molecules.

Interaction of calcium ion with bovine caseins.

In order to clarify the interaction of calcium ion with casein, the volume change associated with the interaction was measured by dilatometric procedures. When CaCl2 was added to the casein solutions at neutral pH, a volume increase occurred and reached a constant saturated value of about 700 ml per 106 g protein with increasing CaCl2 concentrations for whole-, αs- and β-casein solutions, but there was no volume change for κ-casein solution. On the other hand, the binding of calcium ion to the casein fractions was determined by a gel filtration procedure at pH 6.0 to 9.0. The number of Ca2+ ions bound to the caseins increased with the CaCl2 concentration and pH value, and the relative order of binding capacities for the caseins was: αs-casein > whole-casein > β-casein > κ-casein.It was found that the volume changes obtained by the dilatometry were smaller than the calculated volume increases based on the assumption that these are caused by the binding of Ca2+ ion to the caseins. Therefore it is necessary ...

Effect of pH and Complex Formation on Mercury (II) Adsorption by Bentonite

AbstractReactions of Hg with bentonite clay were studied to determine behavior of the metal in aquatic ecosystems. Mercury (II) adsorption by bentonite as a function of pH and complex formation was investigated using a radioisotopic technique. Maximum Hg(II) adsorption in 0.01M Ca(NO3)2 systems occurred in the pH range 4.5–5.5. Varying the Ca(NO3)2 concentration only slightly influenced adsorption or the pH of maximum adsorption.Chloride ions sharply reduced Hg(II) adsorption, especially at low pH's. At pH 6 or lower, increasing CaCl2 concentration from 10−5 to 10−4M depressed adsorption; higher CaCl2 levels were required to decrease adsorption at pH 7. At a given Cl− concentration, maximum observed Hg(II) adsorption occurred near the calculated pH where HgClOH occurred as a transition complex between HgCl2 and Hg(OH)2.Chloride salts (0.01M CaCl2, NaCl, and KCl) were more effective desorbers of Hg(II) than was 0.01M Ca(NO3)2 or various 0.01N acids. HCl (0.01N) removed the most adsorbed Hg(II).

Effect of Calcium Chloride on Prometryne and Fluometuron Adsorption in Soil

The movement and adsorption of soil-applied14C-labeled 2,4-bis(isopropylamino)-6-(methylthio-s-triazine (prometryne) and 1,1-dimethyl-3-(a,a,a-trifluoro-m-tolyl)urea (fluometuron) in the presence of 0.01 and 0.5NCaCl2were studied. The soils were Ca++-saturated Eufaula loamy fine sand and Norge loam. In equilibrium adsorption studies, fluometuron adsorption was decreased and prometryne adsorption was increased by increasing the CaCl2concentration from 0.01 to 0.5N. The mobility of prometryne in the two water-saturated soils was decreased by an increase in CaCl2concentration. Fluometuron mobility was unchanged by the two CaCl2concentrations in Eufaula, but was greater in Norge at the higher CaCl2concentration. The adsorption of each herbicide in the flowing system was less than that predicted by the distribution coefficient. Differences in CaCl2concentration do not appear to influence the mobility of the two herbicides sufficiently at the soil-water flow rate used in this study to require changes in current field application practices.

Interaction between calcium ions and Novocain on the skeletal muscle fiber membrane

Two glass microelectrodes were used to study the action of calcium ions on the rest potential (RP), action potential (AP), and critical potential (CP) of the fibers of the frog's sartorius muscle kept in a novocain solution. An increase of CaCl2 concentration from 1.8 mM to 27 mM restored the amplitude of AP suppressed by the Novocain solution of 5·10−4 g/ml. A combined administration of Novocain solution (0.3·10−4 g/ml) and CaCl2 (0.18 mM) in concentrations which by themselves did not inhibit the electric activity of the fibers led to a complete suppression of AP generation. It has been concluded that calcium and Novocain ions act as antagonists with regard to their influence on the AP amplitude and as synergists with regard to their action on CP.