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21 CFR 184.1193 - Calcium chloride.  

Code of Federal Regulations, 2010 CFR

... Calcium chloride. (a) Calcium chloride (CaCl2 ·2H2 O...10035-04-8) or anhydrous calcium chloride (CaCl2 , CAS...substitution reactions with other calcium and chloride salts...defined in § 170.3(n)(35) of this chapter;...



21 CFR 184.1193 - Calcium chloride.  

Code of Federal Regulations, 2010 CFR

... Calcium chloride. (a) Calcium chloride (CaCl2 ·2H2 O...10035-04-8) or anhydrous calcium chloride (CaCl2 , CAS...substitution reactions with other calcium and chloride salts...defined in § 170.3(n)(35) of this chapter;...



The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2-HCl solutions  

NASA Astrophysics Data System (ADS)

The crystal growth kinetics of calcium sulfate ?-hemihydrate (?-HH) in nearly constant supersaturated HCl-CaCl2 solutions were investigated. Two types of solutions were used, the first had a low HCl (1.4 mol/L) and high CaCl2 (2.8 mol/L) concentration and the second had a high HCl (5.6 mol/L) and low CaCl2 (0.7 mol/L) concentration. These conditions were chosen to represent the first and last stage of a newly developed stage-wise HCl regeneration process. The seeded growth experiments were carried out in a stirred, temperature controlled semi-batch reactor in which supersaturation was kept constant by simultaneous addition of CaCl2 and Na2SO4 solutions. The influence of the following parameters on ?-HH crystal growth was studied: temperature (70-95 C), specific power input of stirring (0.02-1.29 W/kg) and equimolar inflow rate of CaCl2 and Na2SO4 (0-0.6 mol/h). The crystal growth rate was derived from particle size distribution measurements made with the laser light diffraction technique. It was found that the surface area normalized crystal growth rate increased linearly with the molar inflow rate up to 0.3 mol/h, at higher inflow rates no further increase of the growth rate was observed. Temperature and specific power input, within the investigated ranges, did not show a marked effect on the growth rate, attributable to a diffusion/adsorption controlled growth process. An interesting finding of the present research is the establishment of a positive relationship between the narrowing of the width of the particle size distribution with increasing crystal growth rate. The results show that the resulting particle size distribution is positively related to the reagent inflow rate, a finding that can be applied to the industrial design and scale-up of the ?-HH crystallization/HCl regeneration process.

Feldmann, Thomas; Demopoulos, George P.



Calcium and pH homeostasis in the snail ( Helix pomatia ): Effects of CO 2 and CaCl 2 infusion  

Microsoft Academic Search

Rsum Dans l'hmolymphe des escargots (Helix pomatia) traits avec le CO2 le calcium ionique augmente et le pH diminue de telle faon que le produit [Ca++][CO3=] ainsi que l'association du calcium avec l'hmocyanine restent peu prs constant. Le temps requis pour attcindre une situation stable est regl par l'entre lente du CO2. Aprs injection de CaCl2, [Ca++] et [HCO3?

R. F. Burton; R. T. Mathie



Chorda tympani nerve modulates the rat's avoidance of calcium chloride  

PubMed Central

Calcium intake depends on orosensory factors, implying the presence of a mechanism for calcium detection in the mouth. To better understand how information about oral calcium is conveyed to the brain, we examined the effects of chorda tympani nerve transection on calcium chloride (CaCl2) taste preferences and thresholds in male Wistar rats. The rats were given bilateral transections of the chorda tympani nerve (CTX) or control surgery. After recovery, they received 48-h two-bottle tests with an ascending concentration series of CaCl2. Whereas control rats avoided CaCl2 at concentrations of 0.1 mM and higher, rats with CTX were indifferent to CaCl2 concentrations up to 10 mM. Rats with CTX had significantly higher preference scores for 0.316 and 3.16 mM CaCl2 than did control rats. The results imply that the chorda tympani nerve is required for the normal avoidance of CaCl2 solution.

Golden, Glen J.; Voznesenskaya, Anna; Tordoff, Michael G.




Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey



Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride  

USGS Publications Warehouse

Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

Tommasso J.R., Wright, M. I.; Simco, B. A.; Davis, K. B.



The Effects of HCl and CaCl2 Injections on Intracellular Calcium and pH in Voltage-clamped Snail (Helix aspersa) Neurons  

PubMed Central

To investigate the mechanisms by which low intracellular pH influences calcium signaling, I have injected HCl, and in some experiments CaCl2, into snail neurons while recording intracellular pH (pHi) and calcium concentration ([Ca2+]i) with ion-sensitive microelectrodes. Unlike fluorescent indicators, these do not increase buffering. Slow injections of HCl (changing pHi by 0.10.2 pH units min?1) first decreased [Ca2+]i while pHi was still close to normal, but then increased [Ca2+]i when pHi fell below 6.87. As pHi recovered after such an injection, [Ca2+]i started to fall but then increased transiently before returning to its preinjection level. Both the acid-induced decrease and the recovery-induced increase in [Ca2+]i were abolished by cyclopiazonic acid, which empties calcium stores. Caffeine with or without ryanodine lowered [Ca2+]i and converted the acid-induced fall in [Ca2+]i to an increase. Injection of ortho-vanadate increased steady-state [Ca2+]i and its response to acidification, which was again blocked by CPA. The normal initial response to 10 mM caffeine, a transient increase in [Ca2+]i, did not occur with pHi below 7.1. When HCl was injected during a series of short CaCl2 injections, the [Ca2+]i transients (recorded as changes in the potential (VCa) of the Ca2+-sensitive microelectrode), were reduced by only 20% for a 1 pH unit acidification, as was the rate of recovery after each injection. Calcium transients induced by brief depolarizations, however, were reduced by 60% by a similar acidification. These results suggest that low pHi has little effect on the plasma membrane calcium pump (PMCA) but important effects on the calcium stores, including blocking their response to caffeine. Acidosis inhibits spontaneous calcium release via the RYR, and leads to increased store content which is unloaded when pHi returns to normal. Spontaneous release is enhanced by the rise in [Ca2+]i caused by inhibiting the PMCA.

Thomas, Roger C.



Calcium chloride electron injection/extraction layers in organic electronic devices  

NASA Astrophysics Data System (ADS)

Nontoxic calcium chloride (CaCl2) was introduced into organic electronic devices as cathode buffer layer (CBL). The turn-on voltage and maximum luminance of organic light-emitting diode (OLED) with 1.5 nm CaCl2 was 3.5 V and 21 960 cd/m2, respectively. OLED with 1.5 nm CaCl2 possessed comparable electroluminescent characteristics to that of the commonly used LiF. Moreover, the performance of the organic photovoltaic device with 0.5 nm CaCl2 was comparable to that of the control device with LiF. Therefore, CaCl2 has the potential to be used as the CBL for organic electronic devices.

Qu, Bo; Gao, Zhi; Yang, Hongsheng; Xiao, Lixin; Chen, Zhijian; Gong, Qihuang



Electrochemical characteristics of uranium ions in calcium chloride hydrate melts  

NASA Astrophysics Data System (ADS)

Redox reactions of tetravalent uranium ion in calcium chloride hexahydrate CaCl26H2O melt ([CaCl2] = 6.9 M) were studied electrochemically and spectrophotometrically. Cyclic voltammograms in CaCl26H2O melt containing UCl4 were measured with a pyro-graphite carbon working electrode. A cathodic peak corresponding to the reduction of U4+ to U3+ was observed, and it was found to be controlled by the diffusion of U4+ in the melt. Although the concentration of H+ in the melt was negligible, the redox reaction of U4+ was observed without the disturbance of hydrolysis. The formal potential of the U4+|U3+ couple was determined to be -0.483 0.005 V vs. NHE. The diffusion coefficient of U4+ in CaCl26H2O melt was determined to be 1.5 10-7 cm2 s-1 at 300 K. The anodic peak in the voltammogram was attributable to the oxidation of U4+ to UO22+, which was identified by using a technique based on the combination of electrolysis and spectrophotometry. Influences of the water content on chemical status of uranium ions in CaCl2 hydrate melts were studied.

Uehara, A.; Fujii, T.; Nagai, T.; Shirai, O.; Sato, N.; Yamana, H.




Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey



Certification of an air?dry soil for pH and extractable nutrients using one hundredth molar calcium chloride  

Microsoft Academic Search

The preparation of an air?dry river?clay soil as reference soil material for pH and extractable nutrients with a 0.01 M calcium chloride (CaCl2) solution and the homogeneity testing are described. Recommended values for pH and the concentrations of ammonium?nitrogen (NH4?N), total soluble nitrogen (N), phosphorus (P), sodium (Na), potassium (K), and magnesium (Mg) using the unbuffered 0.01M CaCl2 are given.

V. J. G. Houba; I. Novozamsky; D. van Dijk



The role of temperature and CaCl2 in activated sludge dewatering under hydrothermal treatment.  


Dewatering is important for activated sludge disposal. The dewaterability of activated sludge was first deteriorated and then ameliorated when the temperature was raised from 100 to 200C with a threshold temperature of 130C under hydrothermal treatment. Calcium chloride assisted hydrothermal treatment to improve the dewaterability of activated sludge, and eliminated the threshold temperature at as less as 20mg/g dry solid (DS). An increase in temperature and dosage of CaCl2 till 60mg/g DS allowed a continuous improvement of dewaterability. It is found that the charge neutralization resulted from biopolymers solubilization dominated the dewaterability evolution below 160C, while the decomposition of water-binding components played a more important role at higher temperatures. The variation of molecular weight of soluble protein and polysaccharides implies that CaCl2 interacted with the component of sludge and altered the constituent during the hydrothermal treatment. The integration of soluble biopolymers into the floc matrix by CaCl2 contributed to the compacted floc structure and thus improved the dewaterability. This work presents an insight into the floc variation in both the composition and structure associated with the dewaterability and offers a new understanding to the role of temperature and CaCl2 in hydrothermal treatment on activated sludge dewatering. PMID:24355330

Yu, Jie; Guo, Minhui; Xu, Xinhua; Guan, Baohong



Raman spectroscopic studies of chemical speciation in calcium chloride melts  

SciTech Connect

Raman spectroscopy was applied to CaCl2 melts at 900 degrees C under both non-electrolyzed and electrolyzed conditions. The later used titania cathodes supplied by TIMET, Inc. and graphite anodes. Use of pulse-gating to collect the Raman spectra successfully eliminated any interference from black-body radiation and other stray light. The spectrum of molten CaCl2 exhibited no distinct, resolvable bands that could be correlated with a calcium chloride complex similar to MgCl42- in MgCl2 melts. Rather, the low frequency region of the spectrum was dominated by a broad tail arising from collective oscillations of both charge and mass in the molten salt network. Additions of both CaO and Ca at concentrations of a percent or two resulted in no new features in the spectra. Addition of CO2, both chemically and via electrolysis at concentrations dictated by stability and solubility at 900 degrees C and 1 bar pressure, also produced no new bands that could be correlated with either dissolved CO2 or the carbonate ion. These results indicated that Raman spectroscopy, at least under the conditions evaluated in the research, was not well suited for following the reactions and coordination chemistry of calcium ions, nor species such as dissolved metallic Ca and CO2 that are suspected to impact current efficiency in titanium electrolysis cells using molten CaCl2. Raman spectra of TIMET titania electrodes were successfully obtained as a function of temperature up to 900 degrees C, both in air and in-situ in CaCl2 melts. However, spectra of these electrodes could only be obtained when the material was in the unreduced state. When reduced, either with hydrogen or within an electrolysis cell, the resulting electrodes exhibited no measurable Raman bands under the conditions used in this work.

Windisch, Charles F.; Lavender, Curt A.



Aggrandizing power output from Shewanella oneidensis MR-1 microbial fuel cells using calcium chloride.  


There are several interconnected metabolic pathways in bacteria essential for the conversion of carbon electron sources directly into electrical currents using microbial fuel cells (MFCs). This study establishes a direct exogenous method to increase power output from a Shewanella oneidensis MR-1 containing MFC by adding calcium chloride to the culture medium. The current output from each CaCl(2) concentration tested revealed that the addition of CaCl(2) to 1400 ?M increased the current density by >80% (0.95-1.76 ?A/cm(2)) using sodium lactate as the sole carbon source. Furthermore, polarization curves showed that the maximum power output could be increased from 157 to 330 ?W with the addition of 2080 ?M CaCl(2). Since the conductivity of the culture medium did not change after the addition of CaCl(2) (confirmed by EIS and bulk conductivity measurements), this increase in power was primarily biological and not based on ionic effects. Thus, controlling the concentration of CaCl(2) is a pathway to increase the efficiency and performance of S. oneidensis MR-1 MFCs. PMID:22154401

Fitzgerald, Lisa A; Petersen, Emily R; Gross, Benjamin J; Soto, Carissa M; Ringeisen, Bradley R; El-Naggar, Mohamed Y; Biffinger, Justin C



The Effect of Calcium Chloride on Growth, Photosynthesis, and Antioxidant Responses of Zoysia japonica under Drought Conditions  

PubMed Central

Few attempts have been made to study the alleviating effects of signal molecules on zoysiagrass (Zoysiajaponica) under drought stress. Calcium chloride has been shown to ameliorate the adverse effects of drought stress on many plants. It is necessary to investigate how to enhance drought tolerance of zoysiagrass using calcium chloride. The study elucidated the effects of calcium chloride on zoysiagrass under drought conditions by investigating the following parameters: biomass, chlorophyll (Chl) content, net photosynthetic rate (Pn), chlorophyll fluorescence, antioxidant enzymes, proline content, and malondialdehyde (MDA) content. Experimental conditions consisted of an aqueous CaCl2 solution at 5, 10, and 20 mM sprayed on zoysiagrass leaves for 3 d, following by an inducement of drought conditions by withholding water for 16 d. Under drought conditions, all CaCl2 pretreatments were found to increase the above-ground fresh biomass, as well as below-ground fresh and dry biomass. The resulting Chl (a, b, a+b) contents of the 5 and 10 mM CaCl2 pretreatment groups were higher than those of the control. In the later stages of drought conditions, the chlorophyll fluorescence parameter Fv/Fm was higher in leaves treated with 10 mM CaCl2 than in the leaves of the other two treatment groups. Zoysiagrass pretreated with 10 mM CaCl2 possessed both the maximum observed Pn and antioxidant enzyme activities. Meanwhile, lower MDA and proline contents were recorded in the plants pretreated with 5 and 10 mM CaCl2 under drought conditions. As a whole, the drought tolerance of zoysiagrass was improved to some extent by the application of a moderate calcium concentration.

Xu, Chengbin; Li, Xuemei; Zhang, Lihong



Hydroxyapatite Mineralization on the Calcium Chloride Blended Polyurethane Nanofiber via Biomimetic Method  

NASA Astrophysics Data System (ADS)

Polyurethane nanofibers containing calcium chloride (CaCl2) were prepared via an electrospinning technique for the biomedical applications. Polyurethane nanofibers with different concentration of CaCl2 were electrospun, and their bioactivity evaluation was conducted by incubating in biomimetic simulated body fluid (SBF) solution. The morphology, structure and thermal properties of the polyurethane/CaCl2 composite nanofibers were characterized by means of scanning electron microscopy (SEM), field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetry. SEM images revealed that the CaCl2 salt incorporated homogeneously to form well-oriented nanofibers with smooth surface and uniform diameters along their lengths. The SBF incubation test confirmed the formation of apatite-like materials, exhibiting enhanced bioactive behavior of the polyurethane/CaCl2 composite nanofibers. This study demonstrated that the electrospun polyurethane containing CaCl2 composite nanofibers enhanced the in vitro bioactivity and supports the growth of apatite-like materials.

Nirmala, R.; Nam, Ki Taek; Navamathavan, R.; Park, Soo-Jin; Kim, Hak Yong



Hydroxyapatite Mineralization on the Calcium Chloride Blended Polyurethane Nanofiber via Biomimetic Method  

NASA Astrophysics Data System (ADS)

Polyurethane nanofibers containing calcium chloride (CaCl2) were prepared via an electrospinning technique for the biomedical applications. Polyurethane nanofibers with different concentration of CaCl2 were electrospun, and their bioactivity evaluation was conducted by incubating in biomimetic simulated body fluid (SBF) solution. The morphology, structure and thermal properties of the polyurethane/CaCl2 composite nanofibers were characterized by means of scanning electron microscopy (SEM), field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetry. SEM images revealed that the CaCl2 salt incorporated homogeneously to form well-oriented nanofibers with smooth surface and uniform diameters along their lengths. The SBF incubation test confirmed the formation of apatite-like materials, exhibiting enhanced bioactive behavior of the polyurethane/CaCl2 composite nanofibers. This study demonstrated that the electrospun polyurethane containing CaCl2 composite nanofibers enhanced the in vitro bioactivity and supports the growth of apatite-like materials.

Nirmala, R.; Nam, Ki Taek; Navamathavan, R.; Park, Soo-Jin; Kim, Hak Yong



21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2012 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...



21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2011 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...



21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2010 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...



Calcium/Thionyl Chloride Battery Technology.  

National Technical Information Service (NTIS)

This program is structured to develop both active and reserve configuration calcium-thionyl chloride electrochemical cells. The active configuration has required extensive work toward the storability on the calcium-anode in electrolyte solution. A variety...

R. I. Higgins I. Potts



Evaluation of single intratesticular injection of calcium chloride for nonsurgical sterilization of male Black Bengal goats ( Capra hircus): a dose-dependent study  

Microsoft Academic Search

This study describes the induction of chemosterilization in three groups each of six adult male Black Bengal goats at 30 days after a single bilateral intratesticular injection of a calcium chloride (CaCl2, 2H2O) solution at the doses of 10, 20 or 40mg\\/kg body weight\\/testis, always in a 2ml volume of normal saline. Another one group of animals received only 2ml

Kuladip Jana; P. K. Samanta; D. Ghosh



Calcium/Thionyl Chloride Battery Technology.  

National Technical Information Service (NTIS)

This final report documents the development efforts conducted by the Lithium Batteries Group of the Couples Department of Eagle-Picher Industries. The objective of the project was to develop calcium-thionyl chloride cell technology. The original project w...

T. Counts



Solubility of Calcium in CaO-CaCl2.  

National Technical Information Service (NTIS)

The solubility of calcium in CaCl2-CaO melts at 800C was studied. The direct oxide reduction process is used to produce plutonium metal from plutonium dioxide by reaction with calcium. Calcium chloride is added to dissolve the calcium oxide produced, allo...

G. S. Perry S. J. Shaw



EPR and optical absorption studies of copper ions in diglycine calcium chloride tetrahydrate  

NASA Astrophysics Data System (ADS)

EPR study of copper ions in diglycine calcium chloride tetrahydrate (DGCCT), [(NH 2CH 2COOH) 2CaCl 24H 2O] single crystals at room temperature is carried out. The spin Hamiltonian parameters of copper ions are determined as: gx = 2.0238 0.0002, gy = 2.1122 0.0002, gz = 2.2250 0.0002, Ax = (83 2) 10 -4 cm -1, Ay = (86 2) 10 -4 cm -1 and Az = (118 2) 10 -4 cm -1. The optical study of the single crystals at room temperature is also done and the bands are assigned to d-d and charge transfer transitions. Using above data, the nature of bonding in the complex is discussed.

Kripal, Ram; Bajpai, Manisha



Calcium chloride rhenate(VII) dihydrate.  


The crystal structure of calcium chloride rhenate(VII) dihydrate, CaCl(ReO4).2H2O, investigated at 85 K, consists of calcium cations, chloride anions, rhenate(VII) anions and water molecules. In the nearly tetrahedral rhenate(VII) anion, all constituent atoms lie on special positions of m2m (Re) and m (O) site symmetries. The Cl- anion and water O atom lie on special positions of m2m and 2 site symmetries, respectively. The Ca2+ ion, also on a special position (m2m), is eight-coordinated in a distorted square-antiprismatic coordination mode. The crystal has a layered structure stabilized by Ca-O coordination bonds and O-H...Cl hydrogen bonds. PMID:17762100

Jarek, Urszula; Ho?y?ska, Ma?gorzata; Rlepokura, Katarzyna; Lis, Tadeusz



Effect of aluminium on the silica compressibility and transition to the CaCl2-form at high- pressure and high-temperature up to 100 GPa  

NASA Astrophysics Data System (ADS)

The recycling of oceanic crust into the deep Earth offers a way of enriching the mantle in silica. In such a subduction context, the high-pressure phase of silica, stishovite, present in the basaltic and the sedimentary portions of the slab, has been shown to contain significant amounts of aluminium. The incorporation of this element and its possible coupling with oxygen vacancies (Si4+ = Al3+ + " O) can influence significantly the density, compressibility and phase transitions of mantle phases. We investigated the effect of Al on stishovite properties up to ~100 GPa in a YAG or CO2-laser heated diamond anvil cell using in-situ X-ray diffraction at the ID30-ID27 beamline of ESRF. Using an Al-bearing silica glass as starting material, we performed more than 10 different experimental runs at various P and T conditions. Our first observation is that the transition from rutile to calcium chloride (CaCl2) phase of silica occurs at lower pressure, down to 23 GPa at 300 Kelvin, compared to 50 GPa in the pure SiO2 system. [1]. Also, we confirm that the stishovite room pressure volume is increased with increasing Al-content. Still, the volume difference of ~1% at 1 bar rapidly vanishes at higher pressures and the PV equation of state of Al-bearing stishovite at room pressure appears similar to that of Al-free stishovite at all pressures investigated to 100 GPa, within the experimental error. The CaCl2 distortion increases with pressure and decreases with temperature allowing to measure the clapeyron slope of the transition in-situ at high-pressure and high-temperature: dP/dT of 0.02 GPa/K. According to the phase diagram determined by in-situ X-ray diffraction, silica should be in the CaCl2 form in most of the transition and lower mantle. Also, aluminous silica, whether in the rutile or calcium chloride structure, is softer than pure silica. Our results show that the incorporation of ~2.3 weight % of alumina in silica decreases its bulk modulus of around 7-10% in case of the rutile form and of 3.5% in case of the CaCl2 form. References: [1] Andrault et al. (1998) Science, 23, 720-724.

Bolfan-Casanova, N.; Andrault, D.; Guignot, N.; Amiguet, E.



Compatibility of Steel and Aluminium with Calcium Chloride/Ammonia, Magnesium Chloride/Methylamine and Magnesium Chloride/Methylamine/Decane.  

National Technical Information Service (NTIS)

The use of pairs of substances such as calcium chloride/ammonia or magnesium chloride/methylamine for distant heating or heat storage requires compatibility between these substances and the structural materials of the reactor vessels, transport-containers...

H. K. Kohl



A Solution NMR Investigation into the Early Events of Amelogenin Nanosphere Self-Assembly Initiated with Sodium Chloride or Calcium Chloride  

PubMed Central

Using solution-state NMR spectroscopy, new insights into the early events governing amelogenin supramolecular self-assembly have been identified using sodium chloride and calcium chloride to trigger the association. Two-dimensional 1H15N HSQC spectra were recorded for 15N- and 13C-labeled murine amelogenin as a function of increasing NaCl and CaCl2 concentration beginning with solution conditions of 2% acetic acid at pH 3.0, where amelogenin was monomeric. Residue specific changes in molecular dynamics, manifested by the reduction in intensity and disappearance of 1H15N HSQC cross-peaks, were observed with the addition of either salt to the protein. With increasing NaCl concentrations, residues between T21 and R31 near the N-terminus were affected first, suggesting that these residues may initiate amelogenin dimerization, the first step in nanosphere assembly. At higher NaCl concentrations, more residues near the N-terminus (Y12I51) were affected, and with further additions of NaCl, residues near the C-terminus (L141T171) began to show a similar change in molecular dynamics. With increasing CaCl2 concentrations, a similar stepwise change in molecular dynamics involving essentially the same set of amelogenin residues was observed. As the concentration of either salt was increased, a concomitant increase in the estimated overall rotational correlation time (?c) was observed, consistent with assembly. Self-assembly into a dimer or trimer was established with dynamic light scattering studies under similar conditions that showed an increase in diameter of the smallest species from 4.1 nm in the absence of salt to ~10 nm in the presence of salt. These results suggest a possible stepwise interaction mechanism, starting with the N-terminus and followed by the C-terminus, leading to amelogenin nanosphere assembly.

Buchko, Garry W.; Tarasevich, Barbara J.; Bekhazi, Jacky; Snead, Malcolm L.; Shaw, Wendy J.



40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2010 CFR

...false Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....



40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....



40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....



Effect of post-harvest calcium chloride dip treatment and gamma irradiation on storage quality and shelf-life extension of Red delicious apple.  


Freshly harvested Red delicious apples were dipped in calcium chloride solution of varying concentrations (0.5-2.0% w/v) for 1h prior to irradiation at dose level of 0.4kGy. Fruits after radiation treatment were stored at 2??1C, RH 90% and evaluated at intervals of 30days for various quality parameters. Results revealed significant (p???0.05) retention in firmness, juice yield and ascorbic acid content in samples treated with combination of calcium chloride at 2.0% w/v and gamma irradiation (0.4kGy) during storage. Water soluble pectin was inversely correlated with firmness (r?=?0.88) and was significantly (p???0.05) lower in samples subjected to combination treatment of 2.0% w/v CaCl2 and 0.4kGy irradiation throughout the storage. The combination treatment of 2.0% CaCl2 and 0.4kGy irradiation gave about 4.3 log reduction in yeast and mold count of apple samples. Results of the post refrigeration weight loss, firmness and overall acceptability revealed that combination treatment was helpful in extending the shelf-life of Red Delicious apples by around 20-25days at 17??2C, RH 75% following 90days of refrigeration. PMID:23904650

Hussain, P R; Meena, R S; Dar, M A; Wani, A M



Substitution of dietary calcium chloride for calcium carbonate reduces urinary ph and urinary phosphorus excretion in adult cats  

Microsoft Academic Search

In a 44?vvk cross?over study, eight adult cats were given four moist diets containing identical amounts of calcium (13.9 mmol\\/MJ) but with different ratios of calcium carbonate to calcium chloride, the calcium salts providing half of the total dietary calcium. Increasing amounts of calcium chloride were substituted for equimolar amounts of calcium carbonate. Higher intakes of calcium chloride caused significantly

F. J. H. Pastoor; R. Opitz; A. Th. Van t Klooster; A. C. Beynen



Pelleting or Priming Seed with Calcium Improves Groundnut Seedling Survival in Acid Soils  

Microsoft Academic Search

A growth chamber experiment and a field experiment were conducted to investigate the effects of pelleting or priming groundnut seed with calcium (Ca), either as calcium sulfate (CaSO4), calcium chloride (CaCl2), calcium nitrate [Ca(NO3)2], calcium carbonate (CaCO3) or Calcimax on growth of groundnut seedlings in acid soils. In the growth chamber experiment, Ca-treated and non-treated groundnut seeds were planted in

M. R. Murata; G. E. Zharare; P. S. Hammes



Preparation and Characterization of a Calcium Phosphate Ceramic for the Immobilization of Chloride-containing Intermediate Level Waste  

SciTech Connect

Attention has recently been given to the immobilization of special categories of radioactive wastes, some of which contain high concentrations of actinide chlorides. Although vitrification in phosphate glass has been proposed, this was rejected because of the high losses of chloride. On the basis of non-radioactive and, more recently, radioactive studies, we have shown that calcium phosphate is an effective host for immobilizing the chloride constituents [1]. In this instance, the chlorine is retained as chloride, rather than evolved as a chlorine-bearing gas. The immobilized product is in the form of a free-flowing, non-hygroscopic powder, in which the chlorides are chemically combined within the mineral phases chlorapatite [Ca5(PO4)3Cl] and spodiosite [Ca2(PO4)Cl]. Data from studies on non-radioactive simulated waste consisting of a mixture of CaCl2 and SmCl3, and radioactive simulated waste composed of CaCl2 with PuCl3 or PuCl3 and AmCl3, are presented and compared. The XRD data confirm the presence of chlorapatite and spodiosite in the non-radioactive and radioactive materials. The durability of all specimens was measured with a modified MCC-1 test. Releases of Cl after 28 days were 1.6 x 10-3 g m-2 for the non-radioactive specimens and 7 x 10-3 g m-2 for the Pu-bearing specimens. Releases of Ca after 28 days were 0.3 x 10-3 and 2.0 x 10-3 g m-2 for the non-radioactive composition and the Pu composition, respectively, whilst release of Pu from the radioactive specimens was lower for the mixed Pu/Am specimen at 1.2 x 10-5g m-2. The release of Am from the mixed Pu/Am composition was exceptionally low at 2.4 x 10-7 g m-2. Overall, the release rate data suggest that the ceramics dissolve congruently, followed by precipitation of Sm, Pu and Am as less soluble phases, possibly oxides or phosphates. The differences in behaviour noted between non-radioactive and radioactive specimens are interpreted in terms of the crystal chemistry of the individual systems.

Metcalfe, Brian; Donald, Ian W.; Scheele, Randall D.; Strachan, Denis M.



Cathodic behavior of molten CaCl2-CaO and CaCl2-NaCl-CaO  

NASA Astrophysics Data System (ADS)

The cathodic behavior of molten CaCl2, CaCl2-CaO and equimolar CaCl2-NaCl-CaO was studied by cyclic voltammograms and constant potential polarization at temperatures of 1123 to 1173 K on molybdenum and titanium electrodes. The diffusion coefficient of Ca2+ (CaO) in molten CaCl2-CaO was calculated from the linear relationship between the square root of scan rate and the peak current density. The deposition potentials and the potential temperature coefficient of CaO in molten CaCl2-0.5mol%CaO and CaCl2-NaCl-0.5mol%CaO were also obtained from their cyclic voltammograms. The result shows that CaO is more easily reduced than CaCl2. The addition of NaCl in molten CaCl2-CaO induces the underpotential electrodeposition of CaO.

Wang, Shu-Lan; Wang, Wei; Li, Shi-Chao; Cao, Shan-Hui



The influence of magnetic fields on calcium carbonate precipitation  

Microsoft Academic Search

Laboratory experiments were undertaken to assess the effects of magnetic treatment on calcium carbonate precipitate. Static test solutions of calcium chloride, calcium sulphate and sodium carbonate were placed in a magnetic field. After magnetic treatment the solutions CaCl2\\/Na2CO3 and CaSO4\\/Na2CO3 were mixed and changes in precipitation recorded and compared with non-magnetised solutions. The results of this study support earlier work

Rebecca A Barrett; Simon A Parsons



Development of an Inert Anode for Electrowinning in Calcium Chloride-Calcium Oxide Melts  

NASA Astrophysics Data System (ADS)

Studies were performed investigating the anodic testing of calcium ruthenate for electrowinning in calcium chloride-calcium oxide melts. The results showed that calcium ruthenate may be suitable as an inert anode in calcium chloride containing melts as it exhibited a low rate of corrosion in melts containing a small amount of calcium oxide, capable of producing oxygen on its surface, and did not contaminate the melt. To reduce the amount of ruthenium in the anode, solid solutions of calcium ruthenate in calcium titanate were investigated. At low concentrations, the solid solution is a semiconductor with a relatively low conductivity at room temperature, but at the temperature of operation, 1173 K, the material is an excellent electronic conductor. The other way of reducing the amount of ruthenium is to coat the solid solution onto a substrate. In this way, the substrate would give the mechanical strength while the coating would give the electrical conductivity and corrosion protection. Calcium ruthenate-based anodes can endure long-term use in the laboratory under an applied electrical field with oxygen being liberated on the anode indicating that these materials are candidates for the electrowining in calcium chloride-calcium oxide melts.

Jiao, Shuqiang; Fray, Derek J.



Preparation and Partial Characterization of Eggshell Calcium Chloride  

Microsoft Academic Search

To minimize eggshell waste, calcium in eggshells was extracted as calcium chloride using 4% (w\\/v) HCl solution for an extraction period of 3 hs with the ratio of eggshell to HCl being 1:15 (w\\/v). After hydrolysis, the residues were removed by centrifugation at 1774 g for 10 min, and the solution was heated to 110115C until dried, this gave

Wunwiboon Garnjanagoonchorn; Alongkot Changpuak



Effects of Calcium Magnesium Acetate on Small Lentic Environments in Interior Alaska.  

National Technical Information Service (NTIS)

The necessity for finding an alternative deicer to road salt (NaCl, CaCl2) has arisn because significant detrimental impacts are associated with salt usage. Calcium magnesium acetate (CMA) has been identified as a viable alternative to chloride salt. Ongo...

C. L. Rea J. D. LaPerriere



Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats  

PubMed Central

The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was decreased by 41.10%, T. cordifolia at 150, 300, and 450 mg/kg decreased the heart rate by 26.30%, 29.16%, and 38.29%, respectively, and verapamil reduced the heart rate by 9.70% compared to the normal group. The PQRST waves were normalized and atrial and ventricular fibrillation was controlled in rats treated with verapamil and T. cordifolia. CaCl2 increased calcium and sodium levels and decreased potassium levels in blood. T. cordifolia dose-dependently decreased calcium and sodium levels and increased potassium levels. Hence, T. cordifolia can be used in antiarrhythmic clinical settings and beneficial in atrial and ventricular fibrillation and flutter and may be indicated in ventricular tachyarrhythmia.

Sharma, Ashish Kumar; Kishore, Kunal; Sharma, Divya; Srinivasan, B.P; Agarwal, Shyam Sunder; Sharma, Ashok; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh



Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats.  


The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was decreased by 41.10%, T. cordifolia at 150, 300, and 450 mg/kg decreased the heart rate by 26.30%, 29.16%, and 38.29%, respectively, and verapamil reduced the heart rate by 9.70% compared to the normal group. The PQRST waves were normalized and atrial and ventricular fibrillation was controlled in rats treated with verapamil and T. cordifolia. CaCl2 increased calcium and sodium levels and decreased potassium levels in blood. T. cordifolia dose-dependently decreased calcium and sodium levels and increased potassium levels. Hence, T. cordifolia can be used in antiarrhythmic clinical settings and beneficial in atrial and ventricular fibrillation and flutter and may be indicated in ventricular tachyarrhythmia. PMID:23554702

Sharma, Ashish Kumar; Kishore, Kunal; Sharma, Divya; Srinivasan, B P; Agarwal, Shyam Sunder; Sharma, Ashok; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh



Characteristics of two calcium pectinates prepared from citrus pectin using either calcium chloride or calcium hydroxide.  


Calcium pectinate (CaP) was prepared from citrus pectin using either calcium chloride (C-CaP) or calcium hydroxide (HO-CaP) as the source of calcium for the reaction. The production yields and the rates of decalcification for the two calcium pectinates were compared and both found to be lower for C-CaP than for HO-CaP. In an attempt to explain these differences, certain chemical and structural characteristics of the two products, including functional groups (-CH3, C?O, COO-), rheological properties, morphology, and egg-box junction zones, were investigated by Fourier transformation infrared (FTIR) spectroscopy, rheology, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results from FTIR showed that, with an increase in calcium content, the wavenumber values and peak areas of FTIR for -CH3, C?O, and COO- groups all changed dramatically for C-CaP, while they were virtually unchanged for HO-CaP. Rheological analysis of the CaP gel showed that C-CaP had a stronger cross-linked network structure and a greater range of elastic behavior as compared to HO-CaP. SEM images of two CaP gels showed irregular membranes. C-CaP maintained a tight structure and a smooth surface, whereas HO-CaP was loose and rough. The results from XRD revealed a higher degree of crystallinity within C-CaP than within HO-CaP, which indicated that C-CaP possessed compact, ordered, and stable egg-box junction zones while the junction zones in HO-CaP were metastable and loose. PMID:24916205

Guo, Xiujun; Duan, Hanying; Wang, Chao; Huang, Xuesong



Salicylic acid, hydrogen peroxide and calcium-induced saline tolerance associated with endogenous hydrogen peroxide homeostasis in naked oat seedlings  

Microsoft Academic Search

This study investigates the role of salicylic acid (SA), hydrogen peroxide (H2O2) and calcium chloride (CaCl2) singly or in combination, in inducing naked oat plant tolerance to sodium chloride (NaCl). Two-week-old naked oat plants\\u000a were pretreated with both single and double of 0.5mM SA, 0.5mM H2O2 and 5mM CaCl2 by adding them to the culture solution for 24h. At the

Qiang Xu; Xin Xu; Yan Zhao; Kun Jiao; Stephen J. Herbert; Lin Hao



The effects of calcium hydroxide on hydrogen chloride emission characteristics during a simulated densified refuse-derived fuel combustion process.  


This study investigated the effects of different calcium hydroxide (Ca(OH)(2)) addition methods on the potential for hydrogen chloride (HCl) formation in a simulated densified refuse-derived fuel (RDF-5) with single metal combustion system. These experiments were conducted at 850 degrees C with the Ca(OH)(2) spiked in the RDF-5 production or injection in the flue gas treatment system. The results indicated that the potential for HCl formation was decreased significantly by Ca(OH)(2) spiked in the RDF-5 production or injection in the flue gas treatment system. However, the Ca(OH)(2) injection method in the flue gas for HCl emission reduction was better than other method. According to the relationship between the HCl emission and amount of Ca(OH)(2) injected or spiked, it is interesting to find that when the Ca(OH)(2) injected or spiked ranged from 0% to 5%, the potential for HCl formation in the single metal combustion system decreases significantly with increasing Ca(OH)(2) injected or spiked ratio. A corresponding increase in the amount of CaCl(2) partitioned to the fly ash was observed. However, with the ratio of Ca(OH)(2) higher than 5%, the amount of HCl formation showed that no further significant variation occurred with increasing Ca(OH)(2) spiked ratio. PMID:18272287

Chiang, Kung-Yuh; Jih, Jer-Chyuan; Lin, Kae-Long



Removal of arsenic from water by Friedel's salt (FS: 3CaOAl2O3CaCl210H2O).  


Low levels of arsenic can be effectively removed from water by adsorption onto various materials and searching for low-cost, high-efficiency new adsorbents has been a hot topic in recent years. In the present study, the performance of Friedel's salt (FS: 3CaOAl(2)O(3)CaCl(2)10H(2)O), a layered double hydroxide (LDHs), as an adsorbent for arsenic removal from aqueous solution was investigated. Friedel's salt was synthesized at lower temperature (50C) compared to traditional autoclave methods by reaction of calcium chloride with sodium aluminate. Kinetic study revealed that adsorption of arsenate by Friedel's salt was fast in the first 12h and equilibrium was achieved within 48 h. The adsorption kinetics are well described by second-order Lageren equation. The adsorption capacity of the synthesized sorbent for arsenate at pH 4 and 7 calculated from Langmuir adsorption isotherms was 11.85 and 7.80 mg/g, respectively. Phosphate and silicate markedly decreased the removal of arsenate, especially at higher pH, but sulfate was found to suppress arsenate adsorption at lower pH and the adverse effect was disappeared at pH ? 6. Common metal cations (Ca(2+), Mg(2+)) enhanced arsenate adsorption. The results suggest that Friedel's salt is a potential cost-effective adsorbent for arsenate removal in water treatment. PMID:21907487

Zhang, Danni; Jia, Yongfeng; Ma, Jiayu; Li, Zhibao



Effects of calcium hydroxide and calcium chloride addition to bentonite in iron ore pelletization.  


Pyrite ash is created as waste from the roasting of pyrite ores during the production of sulphuric acid. These processes generate great amounts of pyrite ash waste that is generally land filled. This creates serious environmental pollution due to the release of acids and toxic substances. Pyrite ash waste can be utilized in the iron production industry as a blast furnace feed to process this waste and prevent environmental pollution. The essential parameters affecting the pelletization process of pyrite ash were studied using bentonite as a binder. Experiments were then carried out using bentonite and a mixture of bentonite with calcium hydroxide and calcium chloride in order to make the bentonite more effective. The metallurgical properties of pyrite ash, bentonite, calcium hydroxide, calcium chloride, a mixture of these and sintered pellets were studied using X-ray analysis. The crushing strength tests were carried out to investigate the strength of pyrite ash waste pellets. The results of these analyses showed that pyrite ash can be agglomerated to pellets and used in the iron production industry as a blast furnace feed. The crushing strength of the pellets containing calcium hydroxide and calcium chloride in addition to bentonite was better than the strength of pellets prepared using only bentonite binder. PMID:17121116

Tugrul, Nurcan; Derun, Emek Moroydor; Pi?kin, Mehmet



Influence of lactose on the diffusion of calcium ions at physiological temperature.  


Mutual diffusion coefficients for calcium chloride (0.100moldm(-3)) in aqueous solutions containing lactose at various concentrations (from 0.005 to 0.200moldm(-3)) have been measured at 37C (physiological temperature), by using a conductimetric cell coupled to an automatic system to follow the diffusion. This cell uses an open-ended capillary method based on the measurement of the electrical resistance of a solution placed inside the capillaries at recorded times. The analysis of the CaCl2 diffusion coefficient values obtained suggests the presence of some CaCl2/lactose aggregates in the media, which are influenced by the temperature. PMID:24912727

Verissimo, Luis M P; Ribeiro, Vnia C M; Ribeiro, Ana C F; Melia Rodrigo, M; Esteso, Miguel A



Calciothermic reduction of titanium oxide and in-situ electrolysis in molten CaCl 2  

Microsoft Academic Search

A concept for calciothermic direct reduction of titanium dioxide in molten CaCl2 is proposed and experimentally tested. This production process consists of a single cell, where both the thermochemical reaction\\u000a of the calciothermic reduction and the electrochemical reaction for recovery of the reducing agent, Ca, coexist in the same\\u000a molten CaCl2 bath. A few molar percentages of Ca dissolve in

Ryosuke O. Suzuki; Katsutoshi Ono; Koh Teranuma



Effects of postmortem calcium chloride injection on meat palatability traits of strip loin steaks from cattle supplemented with or without zilpaterol hydrochloride.  


An experiment was conducted to determine the effects of zilpaterol hydrochloride mM supplementation (ZH; 8.3 mg/kg on a DM basis for 20 d) and calcium chloride injection [CaCl(2), 200 at 5% (wt/wt) at 72 h postmortem] on palatability traits of beef (Bos taurus) strip loin steaks. Select (USDA) strip loins were obtained from control (no ZH = 19) and ZH-supplemented carcasses (n = 20). Right and left sides were selected alternatively to serve as a control (no INJ) or CaCl(2)-injected (INJ) and stored at 4C. Before injecting the subprimals (72 h postmortem), 2 steaks were cut for proximate, sarcomere length, and myofibrillar fragmentation index (MFI) analyses. At 7 d postmortem each strip loin was portioned into steaks, vacuum packaged, and aged for the appropriate period for Warner-Bratzler shear force (WBSF; 7, 14, 21, and 28 d postmortem), trained sensory analysis (14 and 21 d postmortem), purge loss (7 d), and MFI (3, 7, 14, 21, and 28 d postmortem). Results indicated steaks from both ZH supplementation and INJ had reduced WBSF values as days of postmortem aging increased. The WBSF values of ZH steaks were greater (P < 0.05) than no ZH steaks at each postmortem aging period. The INJ steaks had lower WBSF values (P < 0.05) than non-injected steaks. A greater percentage (91 vs. 71%) of steaks had WBSF values < 4.6 kg from steers with no ZH supplementation at 7 d postmortem, but the percentage did not differ (P > 0.05) due to ZH at 14, 21, or 28 d or due to INJ at any aging period. Trained panelists rated tenderness less in ZH steaks than steaks with no ZH at 14 d and 21 d. However, INJ improved (P < 0.05) the tenderness ratings and flavor intensity of the trained panelists, compared with their non-injected cohorts at 21 d. Zilpaterol hydrochloride supplementation reduced (P < 0.05) MFI values, but INJ resulted in greater (P < 0.05) MFI values compared with no INJ. Subprimals from ZH and INJ showed greater purge loss (P < 0.05). Although no interactions were found with ZH and CaCl(2), injecting USDA Select strip loins from ZH-fed cattle can help reduce the normal WBSF variation as it does in steaks from non-ZH-fed cattle. PMID:22851240

Rodas-Gonzlez, A; Pflanzer, S B; Garmyn, A J; Martin, J N; Brooks, J C; Knobel, S M; Johnson, B J; Starkey, J D; Rathmann, R J; de Felicio, P E; Streeter, M N; Yates, D A; Hodgen, J M; Hutcheson, J P; Miller, M F



Mineral Trioxide Aggregate Mixed with Normal Saline, Calcium Chloride or KY Jelly as Apical Plug in Simulated Open Apices: An In vitro Microleakage Study.  


Introduction: Mineral trioxide aggregate (MTA) mixed with normal saline has short working time, delayed setting time, and poor consistency when used as an apical plug. A preliminary study suggested that substituting normal saline with KY Jelly or 5% calcium chloride (CaCl2) as a vehicle expedites the setting time of MTA. The present in vitro study compared the microleakage of ProRoot MTA mixed with normal saline (MS) to that of ProRoot MTA mixed with KY Jelly and/or 5% CaCl2 in simulated canals with open apices. Materials and methods: Thirty six single-rooted extracted human teeth were cleaned and shaped with ProTaper rotary system to make 36 standardized artificially created open apices. Teeth were randomly divided into three experimental groups (n=10) and two control groups (n=3). In group 1, MTA was mixed with normal saline (MS) and placed into the canals to form 4 to 5 mm apical plugs. In group 2, MTA was mixed with 5% CaCl2 (MC) and in group 3, MTA was mixed with KY Jelly (MK). The other two groups served as positive and negative controls. The remaining canal spaces in the experimental groups were backfilled with thermoplasticized gutta-percha without sealer. Dye penetration and clearing was used to evaluate the sealing ability of each group. The samples were then examined under stereomicroscope to measure the microleakage of different MTA mixtures in mm. Data were statistically analyzed using One-Sample Kolmogorov-Smirnov test for determination of normal distribution and then by one-way ANOVA and Tukey's tests to detect any significance. Results: Positive and negative controls responded as expected. The MS group showed the least mean dye penetration value. There was a significant difference between MS with other groups (P<0.05) but no difference was found between MC and MK groups. Conclusion: Within the limitations of this in vitro study, we can conclude that among these three vehicles, normal saline mixed with ProRoot MTA has the least amount of microleakage in canals with open apices. PMID:24396375

Mehrvarzfar, Payman; Akhavan, Hengameh; Ghasemi, Sara; Khodaei, Fatemeh; Tour Savadkouhi, Sohrab; Dianat, Omid



Mineral Trioxide Aggregate Mixed with Normal Saline, Calcium Chloride or KY Jelly as Apical Plug in Simulated Open Apices: An In vitro Microleakage Study  

PubMed Central

Introduction: Mineral trioxide aggregate (MTA) mixed with normal saline has short working time, delayed setting time, and poor consistency when used as an apical plug. A preliminary study suggested that substituting normal saline with KY Jelly or 5% calcium chloride (CaCl2) as a vehicle expedites the setting time of MTA. The present in vitro study compared the microleakage of ProRoot MTA mixed with normal saline (MS) to that of ProRoot MTA mixed with KY Jelly and/or 5% CaCl2 in simulated canals with open apices. Materials and methods: Thirty six single-rooted extracted human teeth were cleaned and shaped with ProTaper rotary system to make 36 standardized artificially created open apices. Teeth were randomly divided into three experimental groups (n=10) and two control groups (n=3). In group 1, MTA was mixed with normal saline (MS) and placed into the canals to form 4 to 5 mm apical plugs. In group 2, MTA was mixed with 5% CaCl2 (MC) and in group 3, MTA was mixed with KY Jelly (MK). The other two groups served as positive and negative controls. The remaining canal spaces in the experimental groups were backfilled with thermoplasticized gutta-percha without sealer. Dye penetration and clearing was used to evaluate the sealing ability of each group. The samples were then examined under stereomicroscope to measure the microleakage of different MTA mixtures in mm. Data were statistically analyzed using One-Sample Kolmogorov-Smirnov test for determination of normal distribution and then by one-way ANOVA and Tukeys tests to detect any significance. Results: Positive and negative controls responded as expected. The MS group showed the least mean dye penetration value. There was a significant difference between MS with other groups (P<0.05) but no difference was found between MC and MK groups. Conclusion: Within the limitations of this in vitro study, we can conclude that among these three vehicles, normal saline mixed with ProRoot MTA has the least amount of microleakage in canals with open apices.

Mehrvarzfar, Payman; Akhavan, Hengameh; Ghasemi, Sara; Khodaei, Fatemeh; Tour Savadkouhi, Sohrab; Dianat, Omid



Removal of chloride from MSWI fly ash.  


The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. PMID:22947185

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han



Iron availability in peat substrates as assessed by water, calcium chloride, ammonium acetate, DTPA and calcium chloride\\/DTPA  

Microsoft Academic Search

An experiment was conducted to find out which extractant for a peat substrate gave the best prediction of iron (Fe) uptake by the plant. Iron was added in four levels (including zero) to peat in the form of either EDTA or sulphate, at two pH levels. Iron from the peat was extracted by water, 0.01M CaCl2,0.5M NH4OAc, 0.002M DTPA and

C. de Kreij; C. W. van Elderen; H. Bajar



Repassivation Potential of Alloy 22 in Sodium and Calcium Chloride Brines  

SciTech Connect

A comprehensive matrix of 60 tests was designed to explore the effect of calcium chloride vs. sodium chloride and the ratio R of nitrate concentration over chloride concentration on the repassivation potential of Alloy 22. Tests were conducted using the cyclic potentiodynamic polarization (CPP) technique at 75 C and at 90 C. Results show that at a ratio R of 0.18 and higher nitrate was able to inhibit the crevice corrosion in Alloy 22 induced by chloride. Current results fail to show in a consistent way a different effect on the repassivation potential of Alloy 22 for calcium chloride solutions than for sodium chloride solutions.

Rebak, R B; Ilevbare, G O; Carranza, R M



Improvement of activated sludge dewaterability by mild thermal treatment in CaCl2 solution.  


Activated sludge dewatering is of great importance in sludge treatment and disposal. To enhance the dewaterability, a novel method was performed by treating the sludge under mild temperature (50-90 C) in CaCl(2) solution (3.7-1110.0 mg/g dry sludge). The capillary suction time, zeta potential, Fourier-transformed infrared spectra, concentration of soluble protein and carbohydrates were employed to characterize the dewaterability and influencing mechanism. The sludge dewaterability was deteriorated with single thermal treatment, but significantly promoted in CaCl(2) solution and advanced further together with thermal treatment. An increasing CaCl(2) dosage reduced the surface charge remarkably, and a higher temperature could strengthen this impact. The spectra indicate that Ca(2+) could interact with the protein, phenols and O-H functional group in the flocs. The thermal treatment could cause the solubilization of protein and carbohydrates, providing more binding sites for Ca(2+) to establish a strong bridging among the flocs. As CaCl(2) dosage elevated, the soluble carbohydrates showed a reduction trend, while the soluble protein lowered firstly and then bounced back except that remained unchanged at room temperature. A bridging equilibrium is presumed to exist between Ca(2+) and the soluble protein. And the bridging between Ca(2+) and the soluble carbohydrates plays a more important role in the dewatering. The sludge dewaterability was successfully and economically improved by thermal treatment in CaCl(2) solution. PMID:22119238

Guan, Baohong; Yu, Jie; Fu, Hailu; Guo, Minhui; Xu, Xinhua



Evaluation of single intratesticular injection of calcium chloride for nonsurgical sterilization of male Black Bengal goats (Capra hircus): a dose-dependent study.  


This study describes the induction of chemosterilization in three groups each of six adult male Black Bengal goats at 30 days after a single bilateral intratesticular injection of a calcium chloride (CaCl(2), 2H(2)O) solution at the doses of 10, 20 or 40 mg/kg body weight/testis, always in a 2 ml volume of normal saline. Another one group of animals received only 2 ml of normal saline per testis as a control. The induction of chemosterilization was measured using relative testicular weight as well as histomorphological parameters including seminiferous tubular architecture and germ cell association in seminiferous tubules along with morphology of the interstitial space. Biochemical markers included activities of testicular Delta(5), 3beta-hydroxysteroid dehydrogenase (Delta(5), 3beta-HSD), 17beta-hydroxysteroid dehydrogenase (17beta-HSD), catalase, glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) as well as monitoring the level of testicular thiobarbituric acid reactive substances (TBARS), conjugated dienes and reduced glutathione (GSH) content along with plasma concentrations of testosterone, LH and FSH. Histomorphological measures of testes showed total necrosis of testicular tissue at 30 days after an injection of either 20 or 40 mg CaCl(2) along with fibrosis in seminiferous tubules and interstitial spaces. Infiltration of leucocytes was observed with the 40 mg dose. Disintegration of germ cell arrangement in seminiferous tubules and washing out of germ cells from the tubules were noted with the 10mg dose. Relative organ weights, plasma concentrations of testosterone, testicular activities of Delta(5), 3beta-HSD, 17beta-HSD, catalase, GPx, GST, and SOD and testicular contents of GSH all were declined. Increases occurred in testicular TBARS, conjugated dienes and plasma concentrations of LH and FSH with each of the treatments by comparison with the control group. Plasma concentrations of cortisol and fasting blood sugar level as well as packed cell volume (PCV) and total plasma protein were recorded to monitor the changes of chronic stress in the experimental animals. Changes in these parameters were not significant. An intratesticular injection of calcium chloride at specified doses could be a suitable method of sterilization in preference to surgical castration of goats. PMID:15721661

Jana, Kuladip; Samanta, P K; Ghosh, D



Electrochemical Deoxidation of Solid Zirconium Dioxide in Molten Calcium Chloride  

NASA Astrophysics Data System (ADS)

The reduction of zirconium dioxide pellets by electro-deoxidation in molten calcium chloride-calcium oxide (900 C) has been studied. In this technique, the solid oxide is cathodically polarized against a graphite counter electrode under a constant applied potential. Unlike other metal oxides that have been reduced by this technique, only a small area around the cathodic current-collector wire was reduced to zirconium metal with zirconia pellets sintered at ~1100 C; the rest of the sample was largely calcium zirconate. Pellets sintered above 1200 C showed better reduction near the cathode wire and the reduction extended to the entire surface of the pellet with the passage of time. However, reduction of the inner core was found to be increasingly difficult, because the surface metal layer thickened on continuous electro-deoxidation. An analysis of the experimental results showed that the poor electrical conductivity of the intermediate compound, CaZrO3 and its blocky morphology inhibited the electro-deoxidation process. The increase in the sintering temperature of the pellet made it better conducting. However, the pores formed in the thick zirconium metal layer in such samples were too small for an ideal contact between the inner core and the molten electrolyte and hence the reduction of the inner core remained incomplete. Within the scope of this study, it is concluded that preforms with good grain growth and porosity are necessary for the electro-deoxidation of solid zirconium oxide.

Mohandas, K. S.; Fray, D. J.



Crystallization of calcium oxalate in the presence of dodecylammonium chloride  

NASA Astrophysics Data System (ADS)

The influence of cationic surfactant, dodecylammonium chloride (DDACI), on spontaneous crystallization of calcium oxalate has been investigated. A combination of thermogravimetric analysis, X-ray diffraction and optical microscopy was used for crystal phase identification. Properties of the surfactant/electrolyte systems (critical micelle concentration (CMC) and apparent dissociation degree) were determined on the basis of conductivity, surface tension and EMF data. Presence of DDACl did not affect nucleation; calcium oxalate monohydrate (COM) was the only hydrate formed. At the concentration below the CMC, DDACl showed no influence on the volume of the precipitate formed, but at DDACl concentrations equal to or higher than the CMC the overall crystallization was strongly inhibited. The inhibitory effect of DDACl on the crystal growth could be explained by its adsorption on the growing crystal faces, thus reducing the available surface area for further crystal development. The prevention of crystal aggregation observed at all investigated DDACl concentrations could be explained by the formation of a surfactant layer with the ionic headgroups oriented toward liquid phase, what produces electrostatic repulsions between COM particles.

S?krti?, D.; Filipovi?-Vincekovi?, N.; Fredi-Milhofer, H.



Shock-induced irreversible transition from alpha-quartz to CaCl2-like silica  

Microsoft Academic Search

Previous analyses of quartz samples recovered after being submitted to laser shocks of very short duration (nanosecond order) have shown the presence of CaCl2-like silica [T. de Ressguier, P. Berterretche, M. Hallouin, and J. P. Petitet, J. Appl. Phys. 94, 2123 (2003)]. To date, this transition has never been observed under shocks of longer duration (microsecond order) generated by explosives

P. Berterretche; T. de Ressguier; M. Hallouin; J. P. Petitet



Prevention of calcium carbonate precipitation from calcium chloride kill fluid in CO/sub 2/-laden formations  

SciTech Connect

Water containing high concentrations of calcium chloride can now be efficiently used as a kill fluid in production wells having heavily laden carbon dioxide formations. This investigation has determined that the amount of calcium carbonate scale normally produced under these conditions can be reduced by increasing the carbon dioxide partial pressure and increasing the tubing pressure leading from the casing annulus.

Kapelke, M.S.; Caballero, E.P.



Improved control of anthracnose rot in loquat fruit by a combination treatment of Pichia membranifaciens with CaCl(2).  


The beneficial effect of 2% CaCl(2) (w/v) on the antagonistic yeast Pichia membranifaciens for control of anthracnose rot caused by Colletotrichum acutatum in postharvest loquat fruit (Eriobotrya japonica L.) and the possible mechanisms involved were investigated. The results showed that treatment with P. membranifaciens at 1x10(8) CFU ml(-1) or 2% CaCl(2) alone both resulted in significantly smaller lesion diameter and lower disease incidence of anthracnose rot on loquat fruit wounds compared with the controls. The biocontrol activity of P. membranifaciens on the disease was enhanced by the addition of 2% CaCl(2), the combined treatment of P. membranifaciens with CaCl(2) resulted in a remarkably improved control of the disease in comparison with the treatment of P. membranifaciens or CaCl(2) alone. P. membranifaciens in combination with CaCl(2) induced higher activities of two defense-related enzymes chitinase and beta-1,3-glucanase in loquat fruit than applying the yeast or CaCl(2) alone. The in vitro experiment showed that the addition of 2% CaCl(2) in the suspensions of P. membranifaciens significantly inhibited spore germination and germ tube elongation of C. acutatum than the yeast or CaCl(2) alone. However, adding CaCl(2) did not significantly influence the population of P. membranifaciens in NYDB medium or fruit wounds. These results suggest that CaCl(2) could improve the biocontrol activity of P. membranifaciens on anthracnose rot in loquat fruit. It is postulated that the improved control of the disease is directly because of the higher inhibitory effect on pathogen growth and indirectly because of the enhanced disease resistance in loquat fruit by the combination treatment. PMID:18590937

Cao, Shifeng; Zheng, Yonghua; Tang, Shuangshuang; Wang, Kaituo



Electrochemical Deoxidation of Titanium Foam in Molten Calcium Chloride  

NASA Astrophysics Data System (ADS)

Titanium foam, prepared by using a patented powder-metallurgy based process involving a powder blend that was molded, foamed, and sintered using a three-step thermal treatment, was deoxidized in a molten CaCl2 bath. The polarization experiments were carried out by cathodically polarizing the foam (working electrode) against a counter (graphite) electrode. Under constant potential (polarization) mode, the dominant mechanism of deoxidation was the ionization of oxygen, present in the foam, and its subsequent discharge, as CO2/CO, at the anode surface. More than 85 pct oxygen could be effectively removed by carrying out the electro-deoxidation experiments in fresh and pre-electrolyzed melt(s) at an electrolyte temperature of 950 C. Scanning electron microscopy energy dispersive X-ray (SEM-EDX) detection of the deoxidized foams did not show a presence of any inclusion(s) or secondary phase(s).

Tripathy, Prabhat K.; Gauthier, Maxime; Fray, Derek J.



Reference Raman Spectra of CaCl2.nH2O Solids (n= 0, 2, 4, 6).  

NASA Astrophysics Data System (ADS)

Reference Raman spectra of CaCl_2.nH_2O crystals (1003800 cm^1), identified by XRD, are given with a preliminary band assignment. This will help fluid inclusionists for the interpretation of phase changes in CaCl_2-rich aqueous fluid inclusions.

Martinez-Uriarte, L.; Dubessy, J.; Bihannic, I.; Boulet, P.; Robert, P.



Effects of Calcium and Salinity Stress on Quality of Lettuce in Soilless Culture  

Microsoft Academic Search

Lettuce (Lactuca sativa L.) var. Lollo rossa was grown in a floating hydroponic system. Six saline treatments were used, adding different concentrations of calcium chloride (CaCl2) to the nutrient solution (mol m): 0, 2.5, 5, 10, 15, 20, which, respectively, corresponds to an electrical conductivity of 2.5, 3, 3.5, 4.4, 5.4, 6.3 dS m. In plants subjected to moderate salinity

Eva Borghesi; Giulia Carmassi; Maria C. Uguccioni; Paolo Vernieri; Fernando Malorgio



Shock-induced irreversible transition from ?-quartz to CaCl2-like silica  

Microsoft Academic Search

Previous analyses of quartz samples recovered after being submitted to laser shocks of very short duration (nanosecond order) have shown the presence of CaCl2-like silica [T. de Resseguier, P. Berterretche, M. Hallouin, and J. P. Petitet, J. Appl. Phys. 94, 2123 (2003)]. To date, this transition has never been observed under shocks of longer duration (microsecond order) generated by explosives

P. Berterretche; T. de Resseguier; M. Hallouin; J. P. Petitet



Synthesis of needle-like aragonite from calcium chloride and sparingly soluble magnesium carbonate  

Microsoft Academic Search

Needle-like or branch-like aragonite was prepared from sparingly soluble magnesium carbonate and calcium chloride aqueous solution. The morphology, particle size, and aspect ratio (ratio of length to diameter of the particle) of the aragonite particles were characterized with SEM. The polymorphs and crystal size were characterized with XRD. Comparing with the reactants calcium sulfate and sodium carbonate, which were used

Zeshan Hu; Yulin Deng



Don Juan Pond, Antarctica: Near-surface CaCl2-brine feeding Earth's most saline lake and implications for Mars  

PubMed Central

The discovery on Mars of recurring slope lineae (RSL), thought to represent seasonal brines, has sparked interest in analogous environments on Earth. We report on new studies of Don Juan Pond (DJP), which exists at the upper limit of ephemeral water in the McMurdo Dry Valleys (MDV) of Antarctica, and is adjacent to several steep-sloped water tracks, the closest analog for RSL. The source of DJP has been interpreted to be deep groundwater. We present time-lapse data and meteorological measurements that confirm deliquescence within the DJP watershed and show that this, together with small amounts of meltwater, are capable of generating brines that control summertime water levels. Groundwater input was not observed. In addition to providing an analog for RSL formation, CaCl2 brines and chloride deposits in basins may provide clues to the origin of ancient chloride deposits on Mars dating from the transition period from warm/wet to cold/dry climates.

Dickson, James L.; Head, James W.; Levy, Joseph S.; Marchant, David R.



Voluntary Consumption of NaCl, KCl, CaCl2, and NH4Cl Solutions by 28 Mouse Strains  

PubMed Central

Male mice from 28 inbred strains (129P3/J, A/J, AKR/J, BALB/cByJ, BUB/BnJ, C3H/HeJ, C57BL/6J, C57L/J, CAST/Ei, CBA/J, CE/J, DBA/2J, FVB/NJ, I/LnJ, KK/H1J, LP/J, NOD/LtJ, NZB/B1NJ, P/J, PL/J, RBF/DnJ, RF/J, RIIIS/J, SEA/GnJ, SJL/J, SM/J, SPRET/Ei, and SWR/J) were tested with NaCl (75450 mM), KCl (30300 mM), CaCl2 (3100 mM), and NH4Cl (10300 mM) solutions using two-bottle preference tests with water as the second choice. For each mineral, there was a wide range of strain variation in solution intakes and preferences. This variation had a substantial genetic component as assessed using heritability estimates. In most cases, the strain means were continuously distributed; however, strains with deviating high or low intakes or preferences were also observed. The associations among the responses to different minerals were only modest, suggesting distinct genetic controls of sodium, potassium, calcium, and ammonium consumption. These results provide a valuable resource for investigators who wish to identify genes involved in the regulation of mineral consumption and balance.

Bachmanov, Alexander A.; Beauchamp, Gary K.; Tordoff, Michael G.



Acoustic attenuation due to transformation twins in CaCl2: Analogue behaviour for stishovite  

NASA Astrophysics Data System (ADS)

CaCl2 undergoes a tetragonal (P42/mnm) to orthorhombic (Pnnm) transition as a function of temperature which is essentially the same as occurs in stishovite at high pressures. It can therefore be used as a convenient analogue material for experimental studies. In order to investigate variations in elastic properties associated with the transition and possible anelastic loss behaviour related to the mobility of ferroelastic twin walls in the orthorhombic phase, the transition in polycrystalline CaCl2 has been examined using resonant ultrasound spectroscopy (RUS) at high frequencies (0.1-1.5 MHz) in the temperature interval 7-626 K, and dynamic mechanical analysis (DMA) at low frequencies (0.1-50 Hz) in the temperature interval 378-771 K. RUS data show steep softening of the shear modulus as the transition temperature is approached from above and substantial acoustic dissipation in the stability field of the orthorhombic structure. DMA data show softening of the storage modulus, which continues through to a minimum 20 K below the transition point and is followed by stiffening with further lowering of temperature. There is no obvious acoustic dissipation associated with the transition, as measured by tan ?, however. The elastic softening and stiffening matches the pattern expected for a pseudoproper ferroelastic transition as predicted elsewhere. Acoustic loss behaviour at high frequencies fits with the pattern of behaviour expected for a twin wall loss mechanism but with relaxation times in the vicinity of 10-6 s. With such short relaxation times, the shear modulus of CaCl2 at frequencies corresponding to seismic frequencies would include relaxations of the twin walls and is therefore likely to be significantly lower than the intrinsic shear modulus. If these characteristics apply also to twin wall mobility in stishovite, the seismic signature of the orthorhombic phase should be an unusually soft shear modulus but with no increase in attenuation.

Zhang, Zhiying; Schranz, Wilfried; Carpenter, Michael A.



Exogenously applied calcium alleviates cadmium toxicity in Matricaria chamomilla L. plants.  


Cadmium (Cd) toxicity in plants leads to serious disturbances of physiological processes, such as inhibition of chlorophyll synthesis, oxidative injury to the plant cells and water and nutrient uptake. Response of Matricaria chamomilla L. to calcium chloride (CaCl(2)) enrichment in growth medium for reducing Cd toxicity were studied in this study. Hydroponically cultured seedlings were treated with 0, 0.1, 1, and 5 mM CaCl(2), under 0, 120, and 180 ?M CdCl(2) conditions, respectively. The study included measurements pertaining to physiological attributes such as growth parameters, Cd concentration and translocation, oxidative stress, and accumulation of phenolics. Addition of CaCl(2) to growth media decreased the Cd concentration, activity of antioxidant enzymes, and reactive oxygen species accumulation in the plants treated with different CdCl(2), but increased the growth parameters. Malondialdehyde and total phenolics in shoots and roots were not much affected when plants were treated only with different CaCl(2) levels, but it showed a rapid increase when the plants were exposed to 120 and 180 CdCl(2) levels. CaCl(2) amendment also ameliorated the CdCl(2)-induced stress by reducing oxidative injury. The beneficial effects of CaCl(2) in ameliorating CdCl(2) toxicity can be attributed to the Ca-induced reduction of Cd concentration, by reducing the cell-surface negativity and competing for Cd(2+) ion influx, activity enhancement of antioxidant enzymes, and biomass accumulation. PMID:22968674

Farzadfar, Soudeh; Zarinkamar, Fatemeh; Modarres-Sanavy, Seyed Ali Mohammad; Hojati, Mostafa



Calcium-activated chloride channels in the apical region of mouse vomeronasal sensory neurons.  


The rodent vomeronasal organ plays a crucial role in several social behaviors. Detection of pheromones or other emitted signaling molecules occurs in the dendritic microvilli of vomeronasal sensory neurons, where the binding of molecules to vomeronasal receptors leads to the influx of sodium and calcium ions mainly through the transient receptor potential canonical 2 (TRPC2) channel. To investigate the physiological role played by the increase in intracellular calcium concentration in the apical region of these neurons, we produced localized, rapid, and reproducible increases in calcium concentration with flash photolysis of caged calcium and measured calcium-activated currents with the whole cell voltage-clamp technique. On average, a large inward calcium-activated current of -261 pA was measured at -50 mV, rising with a time constant of 13 ms. Ion substitution experiments showed that this current is anion selective. Moreover, the chloride channel blockers niflumic acid and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid partially inhibited the calcium-activated current. These results directly demonstrate that a large chloride current can be activated by calcium in the apical region of mouse vomeronasal sensory neurons. Furthermore, we showed by immunohistochemistry that the calcium-activated chloride channels TMEM16A/anoctamin1 and TMEM16B/anoctamin2 are present in the apical layer of the vomeronasal epithelium, where they largely colocalize with the TRPC2 transduction channel. Immunocytochemistry on isolated vomeronasal sensory neurons showed that TMEM16A and TMEM16B coexpress in the neuronal microvilli. Therefore, we conclude that microvilli of mouse vomeronasal sensory neurons have a high density of calcium-activated chloride channels that may play an important role in vomeronasal transduction. PMID:22732308

Dibattista, Michele; Amjad, Asma; Maurya, Devendra Kumar; Sagheddu, Claudia; Montani, Giorgia; Tirindelli, Roberto; Menini, Anna



Calcium-activated chloride channels in the apical region of mouse vomeronasal sensory neurons  

PubMed Central

The rodent vomeronasal organ plays a crucial role in several social behaviors. Detection of pheromones or other emitted signaling molecules occurs in the dendritic microvilli of vomeronasal sensory neurons, where the binding of molecules to vomeronasal receptors leads to the influx of sodium and calcium ions mainly through the transient receptor potential canonical 2 (TRPC2) channel. To investigate the physiological role played by the increase in intracellular calcium concentration in the apical region of these neurons, we produced localized, rapid, and reproducible increases in calcium concentration with flash photolysis of caged calcium and measured calcium-activated currents with the whole cell voltage-clamp technique. On average, a large inward calcium-activated current of ?261 pA was measured at ?50 mV, rising with a time constant of 13 ms. Ion substitution experiments showed that this current is anion selective. Moreover, the chloride channel blockers niflumic acid and 4,4?-diisothiocyanatostilbene-2,2?-disulfonic acid partially inhibited the calcium-activated current. These results directly demonstrate that a large chloride current can be activated by calcium in the apical region of mouse vomeronasal sensory neurons. Furthermore, we showed by immunohistochemistry that the calcium-activated chloride channels TMEM16A/anoctamin1 and TMEM16B/anoctamin2 are present in the apical layer of the vomeronasal epithelium, where they largely colocalize with the TRPC2 transduction channel. Immunocytochemistry on isolated vomeronasal sensory neurons showed that TMEM16A and TMEM16B coexpress in the neuronal microvilli. Therefore, we conclude that microvilli of mouse vomeronasal sensory neurons have a high density of calcium-activated chloride channels that may play an important role in vomeronasal transduction.

Dibattista, Michele; Amjad, Asma; Maurya, Devendra Kumar; Sagheddu, Claudia; Montani, Giorgia; Tirindelli, Roberto



Chloride salt mixtures affect Gordal cv. green Spanish-style table olive fermentation.  


This work studies the effects of different sodium (in the range of 4-10%), potassium (0-4%) and calcium (0-6%) chloride salt mixtures on the fermentation profile of Gordal olives processed according to the Spanish style. For this purpose, response surface methodology based on a simplex centroid mixture design with constrain (sum of salt percentages = 10%) was used. All treatments reached appropriate titratable acidity levels, but this parameter could not be related to the initial chloride salt concentration. The presence of CaCl(2) led to lower initial and after-fermentation pHs, delayed sugar diffusion into the brine, its maximum concentration and titratable acidity formation. CaCl(2) also delayed Enterobacteriaceae and yeast sprang, decreasing their overall growth. This chloride salt also showed a tendency to reduce overall lactic acid bacteria growth. KCl had a similar behaviour to NaCl but, in general, increased overall microbial growth. Thus, a partial substitution of NaCl in Spanish-style green olives with KCl and CaCl(2) does not substantially modify the fermentation profile but does produce some changes, which, when properly managed, could help to improve product processing. PMID:21839381

Bautista Gallego, J; Arroyo Lpez, F N; Romero Gil, V; Rodrguez Gmez, F; Garca Garca, P; Garrido Fernndez, A



Accelerated Aneurysmal Dilation Associated with Apoptosis and Inflammation in a Newly Developed Calcium Phosphate Rodent Abdominal Aortic Aneurysm Model  

PubMed Central

Objective The Calcium Chloride (CaCl2) model is a widely accepted rodent model for abdominal aortic aneurysm (AAA). Calcium deposition, mainly consisting of calcium phosphate (CaPO4) crystals, has been reported to exist in both human and experimental aneurysms. CaPO4 crystal has been utilized for in vitro DNA transfection by mixing CaCl2 and Phosphate Buffered Saline (PBS). Here, we describe accelerated aneurysm formation resulting from a modification of the CaCl2 model. Methods The modified CaCl2, the CaPO4 model, was created by applying PBS onto the mouse infrarenal aorta after CaCl2 treatment. Morphological, histological and immunohistochemical analyses were performed on arteries treated with both the CaPO4 model and the conventional CaCl2 model as control. In vitro methods were carried out using a mixture of CaCl2 and PBS to create CaPO4 crystals. CaPO4 induced apoptosis of primary cultured mouse vascular smooth muscle cells (VSMCs) was measured by DNA fragmentation ELISA. Results First, we showed that the CaPO4 model produces AAA, defined as an increase of 50% or greater in the diameter of the aorta; faster than in the CaCl2 model. CaPO4 model showed significantly larger aneurysmal dilation at 7, 28, and 42 days as reflected by a maximum diameter fold change (measured in mm) of 1.69 0.07, 1.99 0.14 and 2.13 0.09 as opposed to 1.22 0.04, 1.48 0.07 and 1.680.06 as seen in CaCl2 model, respectively (n=6; P<0.05). A semi-quantitative grading analysis of elastin fiber integrity at 7 days revealed a significant increase in elastin degradation in the CaPO4 model as compared to CaCl2 model (2.70.2 vs 1.50.2, p<0.05, n=6). Significantly higher level of apoptosis occurred in the CaPO4 model (apoptosis index at 1, 2, and 3 days post-surgery: 0.26 0.14, 0.37 0.14, and 0.33 0.08 for CaPO4 model and 0.012 0.10, 0.15 0.02, and 0.12 0.05 for conventional CaCl2 model) (n=3; p<0.05). An enhancement of macrophage infiltration and calcification was also observed at 3 and 7 days in CaPO4. CaPO4 induced approximately 3.7 times more apoptosis in VSMCs when compared to a mixture of CaCl2 (n=4; p<0.0001) in vitro. Conclusion Our data shows that the CaPO4 model accelerates aneurysm formation with the enhancement of apoptosis, macrophage infiltration and calcium deposition. This modified model, with its rapid and robust dilation, can be utilized as a new model for AAA.

Yamanouchi, Dai; Morgan, Stephanie; Stair, Colin; Seedial, Stephen; Lengfeld, Justin; Kent, K. Craig; Liu, Bo



Shock-induced irreversible transition from ?-quartz to CaCl2-like silica  

NASA Astrophysics Data System (ADS)

Previous analyses of quartz samples recovered after being submitted to laser shocks of very short duration (nanosecond order) have shown the presence of CaCl2-like silica [T. de Ressguier, P. Berterretche, M. Hallouin, and J. P. Petitet, J. Appl. Phys. 94, 2123 (2003)]. To date, this transition has never been observed under shocks of longer duration (microsecond order) generated by explosives or plate impacts. While this phase is produced from stishovite under static compression at very high pressure (above 50 GPa) and disappears on pressure release, it is observed after low pressure laser shocks (below 5 GPa) and it is quenched to ambient conditions. The origins of these differences are still unclear. This paper presents complementary laser shock experiments involving setups to provide additional information on the influence of various shock parameters. The results suggest a direct transition from ?-quartz to CaCl2-type silica following a diffusionless mechanism involving high shear strains. They also show the presence of vitreous silica characterized by an ``organized'' ringlike structure, and we propose that this amorphous phase is an intermediate structure between the quartz lattice and grains of the high-pressure phase.

Berterretche, P.; de Ressguier, T.; Hallouin, M.; Petitet, J. P.



Effect of 1-methylcyclopropene and calcium chloride treatments on quality maintenance of 'Lingwu Long' Jujube fruit.  


'Lingwu Long' jujube (Zizyphus jujuba cv. Mill) fruits were harvested at mature-green stages and then treated with 1.0?L L(-1) 1-methylcyclopropene (1-MCP), 1.0% CaCl2 or their combination. All treatments were stored at room temperature (22??1C) and 80-90% relative humidity (RH) up for 15days. Results indicated that 1.0?L L(-1) 1-MCP, 1.0% CaCl2 or their combination were effective in terms of senescence inhibition, and the storage life was extended by 6, 4 and 9days, respectively. 1-MCP and CaCl2 treatment had a synergic effect on the inhibition of ethylene production and microbial population of 'Lingwu Long' jujube fruit. The combination of 1-MCP and CaCl2 significantly reduced polygalacturonase (PG) and polyphenoloxidase (PPO) activities. It also maintained higher concentrations of titratable acid and ascorbic acid. PMID:24741163

Li, Li; Ban, Zhaojun; Li, Xihong; Xue, Ting



The calcium-activated chloride channel Anoctamin 1 contributes to the regulation of renal function.  


The role of calcium-activated chloride channels for renal function is unknown. By immunohistochemistry we demonstrate dominant expression of the recently identified calcium-activated chloride channels, Anoctamin 1 (Ano1, TMEM16A) in human and mouse proximal tubular epithelial (PTE) cells, with some expression in podocytes and other tubular segments. Ano1-null mice had proteinuria and numerous large reabsorption vesicles in PTE cells. Selective knockout of Ano1 in podocytes (Ano1-/-/Nphs2-Cre) did not impair renal function, whereas tubular knockout in Ano1-/-/Ksp-Cre mice increased urine protein excretion and decreased urine electrolyte concentrations. Purinergic stimulation activated calcium-dependent chloride currents in isolated proximal tubule epithelial cells from wild-type but not from Ano1-/-/Ksp-Cre mice. Ano1 currents were activated by acidic pH, suggesting parallel stimulation of Ano1 chloride secretion with activation of the proton-ATPase. Lack of calcium-dependent chloride secretion in cells from Ano1-/-/Ksp-Cre mice was paralleled by attenuated proton secretion and reduced endosomal acidification, which compromised proximal tubular albumin uptake. Tubular knockout of Ano1 enhanced serum renin and aldosterone concentrations, probably leading to enhanced compensatory distal tubular reabsorption, thus maintaining normal blood pressure levels. Thus, Ano1 has a role in proximal tubular proton secretion and protein reabsorption. The results correspond to regulation of the proton-ATPase by the Ano1-homolog Ist2 in yeast. PMID:24476694

Faria, Diana; Rock, Jason R; Romao, Ana M; Schweda, Frank; Bandulik, Sascha; Witzgall, Ralph; Schlatter, Eberhard; Heitzmann, Dirk; Pavenstdt, Hermann; Herrmann, Edwin; Kunzelmann, Karl; Schreiber, Rainer



The solubility of calcium sulphate in simulated nickel sulphatechloride processing solutions  

Microsoft Academic Search

Calcium sulphate solubilities in simulated nickel sulphatechloride processing solutions, as well as the densities of the corresponding saturated solutions, were determined on heating and cooling in a series of experiments carried out from 20 to 95C. The solubility of calcium sulphate decreases progressively with increasing NiSO4 concentrations up to 1.4 M NiSO4, in a base solution containing 0.15 M H2SO4,

J. E. Dutrizac; A. Kuiper



Effects of Dietary Sodium Bicarbonate and Calcium Chloride on Physiological Responses of Lactating Dairy Cows in Hot Weather  

Microsoft Academic Search

Twenty-four lactating cows were as- signed randomly to three treatments to evaluate responses to large differences of dietary sodium and chloride. Treatments were corn-cottonseed meal-corn silage based complete rations with either: 1) .23% sodium chloride (control), 2) control plus 2.28% calcium chloride, or 3) control plus 1.70% sodium bicarbonate.

A. Escobosa; C. E. Coppock; L. D. Rowe Jr; W. L. Jenkins; C. E. Gates



Neonatal Parenteral Nutrition Containing Calcium Chloride and Sodium Phosphate: Mineral Intake and Aluminum Content  

Microsoft Academic Search

Objective. The authors objectives were to determine mineral as well as Al intakes for ?1000 g birth weight (ELBW) infants supported with parenteral nutrition (PN) solutions containing calcium chloride (CaCl) and sodium phosphate (NaPhos). Study design. This study was a prospective cohort study of 32 ELBW infants. Nutrient and Al intakes were recorded based on actual fluid intakes and concentrations

Robert K. Huston; Elizabeth A. McCulley; Andrea M. Markell; Carl F. Heisel; Patrick K. Lewallen



Base Stabilization and Dust Control Using Calcium Chloride and Fly Ash  

Microsoft Academic Search

Field trials were conducted at the TETRA Technologies, Inc. plant site in Lake Charles, Louisiana. A filter cake generated as a by-product in the production of calcium chloride at this plant was investigated for its potential as a dust-controlling agent and for the stabilization of low- volume dirt roads. A laboratory study was initiated prior to the field trials to

D. Saylak; C. K. Estakhri; S. Mishra; D. Sinn


Relations for the determination of the polymorphic composition of calcium carbonate precipitated in saturated sodium chloride solutions  

Microsoft Academic Search

The purification of concentrated sodium chloride solutions from calcium and magnesium ions is realized by precipitating them in the form of calcium carbonate and magnesium hydroxide using a reagent solution composed of sodium carbonate and sodium hydroxide. The functioning of the industrial process depends on the polymorphic composition of the precipitated calcium carbonate. The classical experimental design method is used

C. Berger; A. Dandeu; C. Carteret; B. Humbert; H. Muhr; E. Plasari; J. M. Bossoutrot


Near-Infrared Spectroscopic Investigation of Water in Supercritical CO2 and the Effect of CaCl2  

SciTech Connect

Near-infrared (NIR) spectroscopy was applied to investigate the dissolution and chemical interaction of water dissolved into supercritical carbon dioxide (scCO2) and the influence of CaCl2 in the co-existing aqueous phase at fo empe e : 40 50 75 nd 100 C at 90 atm. Consistent with the trend of the vapor pressure of water, the solubility of pure water in scCO2 inc e ed f om 40 ?C (0.32 mole%) o 100 ?C (1.61 mole%). The presence of CaCl2 negatively affects the solubility of water in scCO2: at a given temperature and pressure the solubility of water decreased as the concentration of CaCl2 in the aqueous phase increased, following the trend of the activity of water. A 40 ?C, the water concentration in scCO2 in contact with saturated CaCl2 aqueous solution was only 0.16 mole%, a drop of more than 50% as compared to pure water while that a 100 ?C was 1.12 mole%, a drop of over 30% as compared to pure water, under otherwise the same conditions. Analysis of the spectral profiles suggested that water dissolved into scCO2 exists in the monomeric form under the evaluated temperature and pressure conditions, for both neat water and CaCl2 solutions. However, its rotational degrees of freedom decrease at lower temperatures due to higher fluid densities, leading to formation of weak H2O:CO2 Lewis acid-base complexes. Similarly, the nearly invariant spectral profiles of dissolved water in the presence and absence of saturated CaCl2 under the same experimental conditions was taken as evidence that CaCl2 dissolution in scCO2 was limited as the dissolved Ca2+/CaCl2 would likely be highly hydrated and would alter the overall spectra of waters in the scCO2 phase.

Wang, Zheming; Felmy, Andrew R.; Thompson, Christopher J.; Loring, John S.; Joly, Alan G.; Rosso, Kevin M.; Schaef, Herbert T.; Dixon, David A.



1H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions  

NASA Astrophysics Data System (ADS)

The 1H NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheometry have been applied to study the ionic gelation of 1% w/w aqueous low methoxyl pectin solution induced by divalent Ca2+ cations from a calcium chloride solution. The model-free approach to the analysis of 1H NMR relaxometry data has been used to separate the information on the static (?) and dynamic () behaviour of the systems tested. The 1H NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (?, and T2 vs. CaCl2 concentration) is consistent with the two-stage gelation process of low methoxyl pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl2) is followed by the appearance of weak inter-dimer aggregations (for CaCl2? 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl2 has been confirmed by rheological measurements. Apart from that, the T1 and T2 relaxation times have been found to be highly sensitive to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability.

Dobies, M.; Ku?mia, S.; Jurga, S.



Injection of Inositol 1,3,4,5-Tetrakisphosphate into Xenopus Oocytes Generates a Chloride Current Dependent upon Intracellular Calcium  

Microsoft Academic Search

Injection of inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P4) into voltage-clamped oocytes of Xenopus laevis elicited an oscillatory chloride membrane current. This response did not depend upon extracellular calcium, because it could be produced in calcium-free solution and after addition of cobalt to block calcium channels in the surface membrane. However, it was abolished after intracellular loading with the calcium chelating agent EGTA, indicating

I. Parker; R. Miledi



Electronic and Elastic Properties of CrO2 in the Orthorhombic CaCl2-TYPE Structure  

NASA Astrophysics Data System (ADS)

The structure, electronic and elastic properties of CrO2 in the high pressure orthorhombic CaCl2 (Pnnm) phase are investigated by first-principles calculations based on density functional theory (DFT). Our calculated crystal parameters are in good agreement with the available experimental data. The electronic band structure, density of state (DOS) and projected density of state (PDOS) at 14 GPa are studied within local spin density approximation (LSDA) and generalized gradient approximation (GGA) in details. The CaCl2 phase of CrO2 still has the half metal character, which is in accordance with previous theoretical predictions. The elastic constants, bulk modulus, shear modulus, Young's modulus and Poisson ratio under pressures are successfully obtained for the orthorhombic CaCl2 phase of CrO2. This structure is mechanically stable at our applied range of pressures. The calculated elastic anisotropic factors show that the CaCl2 phase of CrO2 is provided with high elastic anisotropy and the elastic anisotropy decreases with increasing pressures. The propagation speed of transverse, longitudinal elastic wave together with associated Debye temperatures are also estimated.

Wu, H. Y.; Chen, Y. H.; Deng, C. R.; Su, X. F.



Crystalline transition and morphology variation of polyamide 6/CaCl2 composite during the decomplexation process  

NASA Astrophysics Data System (ADS)

In this work, we developed a new method to prepare porous PA6 with different morphologic feature and crystalline forms via the decomplexation of PA6/CaCl2 composite. The structures and morphology of thus obtained materials were characterized by vibrational spectroscopy (FT-IR and Raman) and scanning electron microscope (SEM) method. When amorphous PA6/CaCl2 composite films were treated in water at room temperature, PA6 re-arranges into ? form. However, decomplexation of the PA6/CaCl2 composite in boiling water produces PA6 in ? crystalline form. If the PA6/CaCl2 composite is soaked in methanol, part of PA6 is dissolved or swollen in methanol/metal salt solutions. As a result, a dissolve/precipitation process occurred during the decomplexation process, which led to the formation of PA6 in ? crystalline form. Further investigation demonstrates that the morphologies of the porous PA6 could be adjusted by using different solvents and/or different decomplexation conditions.

Liu, Shaoxuan; Zhang, Chengfeng; Proniewicz, Edyta; Proniewicz, Leonard M.; Kim, Younkyoo; Liu, Jun; Zhao, Ying; Xu, Yizhuang; Wu, Jinguang



Crystalline transition and morphology variation of polyamide 6/CaCl2 composite during the decomplexation process.  


In this work, we developed a new method to prepare porous PA6 with different morphologic feature and crystalline forms via the decomplexation of PA6/CaCl2 composite. The structures and morphology of thus obtained materials were characterized by vibrational spectroscopy (FT-IR and Raman) and scanning electron microscope (SEM) method. When amorphous PA6/CaCl2 composite films were treated in water at room temperature, PA6 re-arranges into ? form. However, decomplexation of the PA6/CaCl2 composite in boiling water produces PA6 in ? crystalline form. If the PA6/CaCl2 composite is soaked in methanol, part of PA6 is dissolved or swollen in methanol/metal salt solutions. As a result, a dissolve/precipitation process occurred during the decomplexation process, which led to the formation of PA6 in ? crystalline form. Further investigation demonstrates that the morphologies of the porous PA6 could be adjusted by using different solvents and/or different decomplexation conditions. PMID:23892342

Liu, Shaoxuan; Zhang, Chengfeng; Proniewicz, Edyta; Proniewicz, Leonard M; Kim, Younkyoo; Liu, Jun; Zhao, Ying; Xu, Yizhuang; Wu, Jinguang



Anoctamin 1 induces calcium-activated chloride secretion and proliferation of renal cyst-forming epithelial cells.  


Polycystic kidney diseases are characterized by multiple bilateral renal cysts that gradually enlarge and lead to a decline in renal function. Cyst enlargement is driven by transepithelial chloride secretion, stimulated by enhanced levels of cyclic adenosine monophosphate, which activates apical cystic fibrosis transmembrane conductance regulator chloride channels. However, chloride secretion by calcium-dependent chloride channels, activated through stimulation of purinergic receptors, also has a major impact. To identify the molecular basis of calcium-dependent chloride secretion in cyst expansion, we determined the role of anoctamin 1 and 6, two recently discovered calcium-activated chloride channels both of which are expressed in epithelial cells. We found that anoctamin 1, which plays a role in epithelial fluid secretion and proliferation, is strongly expressed in principal-like MDCK cells (PLCs) forming cysts within a collagen matrix, in an embryonic kidney cyst model, and in human autosomal dominant polycystic kidney disease tissue. Knockdown of anoctamin 1 but not anoctamin 6 strongly diminished the calcium-dependent chloride secretion of PLCs. Moreover, two inhibitors of anoctamin ion channels, tannic acid and a more selective inhibitor of anoctamin 1, significantly inhibited PLC cyst growth and cyst enlargement in an embryonic kidney cyst model. Knockdown of ANO1 by morpholino analogs also attenuated embryonic cyst growth. Thus, calcium-activated chloride secretion by anoctamin 1 appears to be a crucial component of renal cyst growth. PMID:24152967

Buchholz, Bjoern; Faria, Diana; Schley, Gunnar; Schreiber, Rainer; Eckardt, Kai-Uwe; Kunzelmann, Karl



Origin of CaCl2 brines by basalt-seawater interaction: Insights provided by some simple mass balance calculations  

NASA Astrophysics Data System (ADS)

Modern rift zone hydrothermal brines are typically CaCl2-bearing brines, an unusual chemical signature they share with certain oil field brines, fluid inclusions in ore minerals and a few uncommon saline lakes. Many origins have been suggested for such CaCl2 brines but in the Reykjanes, Iceland, geothermal system a strong empirical case can be made for a basalt-seawater interaction origin. To examine this mechanism of CaCl2 brine evolution some simple mass balance calculations were carried out. Average Reykjanes olivine tholeiite was reacted with average North Atlantic seawater to make an albite-chlorite-epidotesphene rock using Al2O3 as the conservative rock component and Cl as the conservative fluid component. The excess components released by the basalt to the fluid were precipitated at 275 C as quartz, calcite, anhydrite, magnetite and pyrite to complete the conversion to greenstone. The resulting fluid was a CaCl2 brine of seawater chlorinity with a composition remarkably similar to the actual Reykjanes brine at 1750 m depth. Thus, the calculations strongly support the idea that the Reykjanes CaCl2 brines result from closed system oceanic basalt-seawater interaction (albitization chloritization mechanism) at greenschist facies temperatures. The calculation gives a seawater: basalt mass ratio of 3?1 to 4?1 (vol. ratio of 9?1 to 12?1), in keeping with experimental results, submarine vent data and with ocean crust cooling calculations. The brine becomes anoxic because there is insufficient dissolved or combined oxygen to balance all the Fe released from the basalt during alteration. Large excesses of Ca are released to the fluid and precipitate out in the form of anhydrite which essentially sweeps the brine free of sulfate leaving an elevated Ca concentration. The calculated rock-water interaction basically involves Na + Mg + SO4 ? Ca + K, simulating chemical differences observed between oceanic basalts and greenstones from many mid-ocean ridges.

Hardie, Lawrence A.



Pretreatment of microcrystalline cellulose flakes with CaCl2 increases the surface area, and thus improves enzymatic saccharification.  


Glucose production from cellulose flakes with cellulases was improved after pretreatment with saturated CaCl2 at room temperature. When pretreated microcrystalline cellulose flakes (Funacel II, Funakoshi Co., Ltd, Tokyo, Japan) were saccharified with the cellulases, 76.8% of the substrate was converted into glucose within 5 h, whereas the corresponding conversion rate of water-pretreated cellulose flakes was 33.8%. To clarify the mechanism of the promotion, cellobiohydrolase I purified from Trichoderma longibrachiatum was used as the model cellulase, which degraded CaCl2-pretreated cellulose more quickly than the water-pretreated cellulose under tested conditions. The maximum amount of the enzyme bound to CaCl2-pretreated cellulose at 37 degrees C was estimated as 1.14 nmol/mg of cellulose, whereas that to water-pretreated cellulose was 0.527 nmol/mg of cellulose. The specific activity of the bound enzyme greatly decreased with the increase of the surface density (rho) of the bound enzyme, and no significant positive effects of the CaCl2-pretreatment on the specific activity could be observed at the same rho value, suggesting that the promotion was attributed mainly to the increase of the surface area of cellulose. The effect was also observed with dewaxed cotton or filter paper, but not with nata de coco cellulose or bagasse cellulose as the substrates. This suggests that the CaCl2-pretreatment serves to increase the surface area of cellulose flakes via liberation of cellulose particles which were artificially aggregated during harsh drying processes of the flakes. PMID:18384760

Tokuyasu, Ken; Tabuse, Mine; Miyamoto, Maki; Matsuki, Junko; Yoza, Koichi



Preparation and characterization of poly(vinyl chloride) calcium carbonate nanocomposites via melt intercalation  

Microsoft Academic Search

Calcium carbonate was synthesized by insitu deposition technique and its nano size (3560nm) was confirmed by transmission\\u000a electron microscopy (TEM). Composites of the filler CaCO3 (micro and nano) and the matrix poly(vinyl chloride) (PVC) were prepared with different filler loadings (05wt%) by melt\\u000a intercalation. Brabender torque rheometer equipped with an internal mixer has been used for preparation of formulations for

C. B. Patil; U. R. Kapadi; D. G. Hundiwale; P. P. Mahulikar



Effect of Calcium Sulphate Nanoparticles on Fusion, Mechanical and Thermal Behaviour Polyvinyl Chloride (pvc)  

Microsoft Academic Search

Calcium Sulphate [CaSO4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO4 (micro and nano) and the matrix poly (vinyl chloride) (PVC) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer

C. B. Patil; P. S. Shisode; U. R. Kapadi; D. G. Hundiwale; P. P. Mahulikar



Effect of calcium chloride on the isobaric vapor-liquid equilibrium of 1-propanol + water  

Microsoft Academic Search

The effect of calcium chloride at salt mole fractions from 0.02 to saturation on the vapor-liquid equilibrium (VLE) of 1-propanol + water has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited a salting-out effect of the alcohol over the whole range of liquid composition, the azeotrope being eliminated at salt mole fractions greater than

Maria C. Iliuta; Fernand C. Thyrion; Ortansa M. Landauer



A combined treatment of landfill leachate using calcium oxide, ferric chloride and clinoptilolite.  


The aim of this research was development of appropriate procedure for treatment of landfill leachate taken from old sanitary landfill Piskornica (Koprivnica, Croatia). Due to complex nature of the effluent a combined treatment approach was applied. Samples were treated with calcium oxide followed by ferric chloride and finally with clinoptilolite. The optimum amount of treating agents and contact time were determined. Application of calcium oxide (25 g/L, 20 min. contact time) resulted in the reduction of color, turbidity, suspended solids and ammonia for 94.50%, 96.55%, 95.66% and 21.60%, respectively, while the removal efficiency of Cr (VI), Fe, Ni, Cu, Zn and Pb was 75.00%, 95.34%, 56.52%, 78.72%, 73.02% and 100.00%, respectively. After addition of ferric chloride (570 mg Fe(3+)/L, 20 min. contact time) removal efficiency of color, turbidity, suspended solids and ammonia increased to 96.04%, 99.27%, 98.61%, and 43.20%, respectively. Removal of ammonia (81.60%) increased significantly after final adsorption onto clinoptilolite (25 g/L, 4 h contact time). Removal of COD after successive treatment with calcium oxide, ferric chloride and clinoptilolite was 64.70%, 77.40% and 81.00%, respectively. PMID:21308604

Orescanin, Visnja; Ruk, Damir; Kollar, Robert; Mikelic, Ivanka Lovrencic; Nad, Karlo; Mikulic, Nenad



Calcium effect on the solubility of sodium dodecyl sulfate in sodium chloride solutions  

SciTech Connect

Interactions between calcium ions and anionic surfactants have recently attracted increased interest, particularly because of the development of enhanced oil recovery through the use of micellar solutions. The brine in crude oil reservoirs always contains a certain amount of polyvalent ions, especially calcium ions, which have pronounced effects on the properties of micellar solutions, varying with electrolyte concentration and surfactant type. To date, the surfactants most often used are anionic. Precipitation of anionic surfactants with calcium ions was investigated. It was found that surfactant precipitation is governed by a given mechanism when the supernatant liquid is a micellar solution, and by another when it is not. This work discusses the results of a series of experiments which indicate that this difference is a function of sodium chloride concentration. 10 references.

Baviere, M.; Bazin, B.; Aude, R.



The effect of additions of alkaline-earth metal chlorides on the setting behavior of a refractory calcium aluminate cement  

Microsoft Academic Search

The literature concerned with the effect of alkaline and alkaline-earth metal chlorides on the hydration of calcium aluminate cements is confused. For example, some authors have suggested that magnesium chloride acts as a retarder, while others stated that it acts as an accelerator. Accordingly a thorough investigation has been carried out into the setting behaviour and early hydration of Secar

Nilforoushan; JH Sharp



Hypoxia-inducible factor-1? causes renal cyst expansion through calcium-activated chloride secretion.  


Polycystic kidney diseases are characterized by numerous bilateral renal cysts that continuously enlarge and, through compression of intact nephrons, lead to a decline in kidney function over time. We previously showed that cyst enlargement is accompanied by regional hypoxia, which results in the stabilization of hypoxia-inducible transcription factor-1? (HIF-1?) in the cyst epithelium. Here we demonstrate a correlation between cyst size and the expression of the HIF-1?-target gene, glucose transporter 1, and report that HIF-1? promotes renal cyst growth in two in vitro cyst models-principal-like MDCK cells (plMDCKs) within a collagen matrix and cultured embryonic mouse kidneys stimulated with forskolin. In both models, augmenting HIF-1? levels with the prolyl hydroxylase inhibitor 2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetate enhanced cyst growth. In addition, inhibition of HIF-1? degradation through tubule-specific knockdown of the von Hippel-Lindau tumor suppressor increased cyst size in the embryonic kidney cyst model. In contrast, inhibition of HIF-1? by chetomin and knockdown of HIF-1? both decreased cyst growth in these models. Consistent with previous reports, plMDCK cyst enlargement was driven largely by transepithelial chloride secretion, which consists, in part, of a calcium-activated chloride conductance. plMDCKs deficient for HIF-1? almost completely lacked calcium-activated chloride secretion. We conclude that regional hypoxia in renal cysts contributes to cyst growth, primarily due to HIF-1?-dependent calcium-activated chloride secretion. These findings identify the HIF system as a novel target for inhibition of cyst growth. PMID:24203996

Buchholz, Bjoern; Schley, Gunnar; Faria, Diana; Kroening, Sven; Willam, Carsten; Schreiber, Rainer; Klanke, Bernd; Burzlaff, Nicolai; Jantsch, Jonathan; Kunzelmann, Karl; Eckardt, Kai-Uwe



Nitrogen-containing mesoporous carbons prepared from melamine formaldehyde resins with CaCl2 as a template.  


Melamine formaldehyde resins were synthesized with encapsulated CaCl(2) as a template. Carbonization at high temperatures led to the formation of carbon materials containing N atoms. Washing with de-ionized water removed encapsulated CaCl(2), resulting in the formation of mesopores (3-30 nm) with the high surface areas (770-1300 m(2)/g). The template can be recycled and the method is simple and cost effective as compared to the hard template techniques. The mesoporous carbons containing nitrogen (NMC) thus prepared exhibited the amphipathic surfaces (both hydrophilic and lipophilic) and adsorbed great amount of water and benzene. In addition, the incorporated N atoms exhibited quite strong basicity for the adsorption of great amount of SO(2). PMID:21840533

Huang, Yu'an; Yang, Feng; Xu, Zheng; Shen, Jianyi



Effect of CaCl2 concentration on the rate of foreign gene transfer and expression by in vivo electroporation in the mouse ovary.  


We tested the effect of electroporation (EP) medium composition on the rate of gene transfer and expression in the mouse ovary in vivo. FITC labeled oligonucleotides were dissolved in a medium with varying levels of CaCl2 concentration from 0 to 250 mM, and transferred by in vivo EP. Gene transfer efficiency was assessed by examining fluorescence signal intensity with a fluorescent microscope at 3 h after in vivo EP. The results indicated that CaCl2 concentration at 50 mM gave the highest transfer efficiency of the oligonucleotides only in the presence of phosphate buffered saline (PBS). Without PBS or CaCl2, the oligonucleotide transfer was negligible. A further increase in CaCl2 from 50 to 250 mM lowered the transfer efficiency. Little fluorescence signal was attained by substituting CaCl2 for MgCl2, NaCl or KCl. Addition of glycerol to the EP medium with 50 mM CaCl2 did not improve the transfer efficiency in the presence of PBS, although a marginal increase was observed in the absence of PBS. The stimulating effect of increased CaCl2 concentration from 0 to 50 mM was further evaluated by examining the intensity of reporter protein expression after transferring the bacterial lacZ gene. The results of X-gal staining demonstrated that CaCl2 with a range of 20 to 100 mM, showed enhanced gene expression in comparison with 0 mM. However, no remarkable difference was observed between the different CaCl2 concentrations, suggesting that the stimulating effect of CaCl2 on gene transfer and expression in the mouse ovary in vivo may not necessarily parallel in terms of the optimal concentration. PMID:12883653

Suzuki, Takayuki; Tsunekawa, Jun; Murai, Atsushi; Muramatsu, Tatsuo



Solubilities of Chloride Salts of Alkali and Alkaline-Earth Metals When Sparged with Hydrogen Chloride.  

National Technical Information Service (NTIS)

The effects of hydrogen chloride (HCl) concentration and temperature on the solubility and hydration state of the alkali chlorides LiCl, NaCl, and KCl and the alkaline-earth chlorides, MgCl2, and CaCl2 were investigated by the Bureau of Mines. Saturated a...

E. G. Noble D. E. Shanks D. J. Bauer



[Effect of suloctidil on the contractions of isolated rat aortic strips induced by norepinephrine and CaCl2].  


The mode for the antispasmodic action of suloctidil was examined using aorta strips of rats in vitro. Both 10 microM suloctidil and 0.1 microM verapamil non-competitively inhibited the norepinephrine (NE)-induced contraction, of which pD'2 values were 4.61 +/- 0.41 and 6.16 +/- 0.22, respectively. Prazosin at 1 nM competitively inhibited the NE-induced contraction, and its pA2 value was 9.84 +/- 0.15. In the depolarized aorta, suloctidil competitively inhibited the CaCl2-induced contraction at the concentrations of 0.1 and 1.0 microM, of which the pA2 value was 5.96 +/- 0.26. However, 10 microM suloctidil inhibited the CaCl2-induced contraction in a non-competitive manner, and its pD'2 value was 5.01 +/- 0.14. The pA2 values for papaverine, verapamil and cinnarizine were found to be 5.23 +/- 0.10, 7.53 +/- 0.09 and 7.11 +/- 0.11 in CaCl2 induced contraction, respectively. In a Ca2+ free medium, 1 microM NE caused a transient contraction, which was maximum (23.8 +/- 2.2% of that in a normal solution) at 0.4 min after the application of NE. Subsequent application of 2.5 and 10 mM CaCl2 evoked a gradual contractile response, of which the maximum was 103.1 +/- 4.2% and 133.8 +/- 10.3% of that in a normal solution, respectively. Initial phasic contraction induced by NE in a Ca2+ free medium was not affected by 10 microM suloctidil nor by 0.1 microM verapamil, while this contraction was significantly suppressed by 1 nM prazosin. The tonic contraction, however, induced by re-application of CaCl2 was significantly suppressed by 10 microM suloctidil, 0.1 microM verapamil and 1 nM prazosin. Furthermore, 1.0 microM suloctidil and 0.1 microM verapamil significantly suppressed the 45Ca uptake into the depolarized aorta 5 and 10 min after the addition of 45CaCl2. On the contrary, suloctidil had no influence on the phosphodiesterase activity prepared from the aorta of rats even at 10 microM, whereas 1.0 microM papaverine inhibited the enzyme activity. It is concluded that suloctidil and verapamil inhibit the contractions of the isolated rat aorta induced by NE and CaCl2 through the inhibition of the influx of Ca2+ without affecting the intracellular Ca2+ release. PMID:6323288

Ishibashi, A; Hanagata, R; Horii, D; Hisayama, T; Takayanagi, I



Automated determination of micro amounts of phosphate in dilute calcium chloride extracts of soils  

Microsoft Academic Search

An Auto Analyzer II method for the colorimetric determination of micro amounts of phosphorus (<100 ?g\\/L) in 0.01 M CaCl2 soil extracts is described. The automated procedure gave results not significantly different from manual determinations.Using data derived from four soils extracted in triplicate on three separate occasions, the relative confidence intervals for a single sample determination were found to be

L. A. Warrell; P. W. Moody



Reduction of gray mold development in table grapes by preharvest sprays with ethanol and calcium chloride  

Microsoft Academic Search

Preharvest applications of a 16% ethanol (EtOH) solution, containing 1% CaCl2, reduced gray mold development in Chasselas table grapes picked at a late harvest date. The losses due to rotten clusters dropped from 15% in controls to 5% in grapes treated with EtOH+CaCl2. Over 6 weeks cold storage, the losses due to gray mold rots were reduced by 50% in

Christian Chervin; Daniel Lavigne; Pascale Westercamp



Effects of Postmortem Injection Time, Injection Level, and Concentration of Calcium Chloride on Beef Quality Traits  

Microsoft Academic Search

Two experiments were conducted to determine the optimum protocol for maximizing meat quality with CaC12 injection. Experiment 1 compared the effects of 30 min or 24 h postmortem injection of 175 mM CaCl2 or water at 10% (wt\\/wt) to controls on various measures of meat quality. An injection of CaC12 reduced (P < .05) shear force values in all three

T. L. Wheeler; M. Koohmaraie; J. L. Lansdell; G. R. Siragusa; M. F. Miller


Phase transitions in the brominated ferroelectric tris-sarcosine calcium chloride.  


We demonstrate that the Curie temperature, Tc , of tris-sarcosine calcium chloride can be lowered from 130 K to near 0 K by chemical doping of the anion. In the low temperature limit, quantum fluctuations persist over a range of chemical doping concentrations. Below TC the temperature dependence of the fractional length change, ?LLo, scales as (?LLo)-1=a+a1t? (red line) where t is the reduced temperature, and ? = -1.5. The behavior of linear coefficient of thermal expansion near TC is shown in the inset. Three additional phase transitions near 43, 50, and 61 K are resolved. PMID:24789107

Lashley, J C; Munns, J H D; Echizen, M; Ali, M N; Rowley, S E; Scott, J F



The effect of postharvest calcium application in hydro-cooling water on tissue calcium content, biochemical changes, and quality attributes of sweet cherry fruit.  


To improve storage/shipping quality of sweet cherry (Prunus avium L.), the effect of calcium chloride (CaCl2) added to hydro-cooling water on physiological and biochemical processes related to fruit and pedicel quality was investigated on two major cultivars. The fruit tissue Ca content increased up to 29-85% logarithmically for 'Sweetheart' and 39-188% linearly for 'Lapins' as CaCl2 rate increased from 0.2% to 2.0% at 0 C for 5 min. The increase of fruit tissue Ca content was accompanied by reductions in respiration rate, ascorbic acid degradation, and membrane lipid peroxidation, which enhanced total phenolics content and total antioxidant capacity, and resulted in increases in fruit firmness and pitting resistance and decreases in titratable acidity loss and decay of both cultivars. Pedicel browning was inhibited by CaCl2 at 0.2% and 0.5%, but increased by higher rates at 1.0% and 2.0%, possibly via modifying membrane lipid peroxidation. PMID:24799204

Wang, Yan; Xie, Xingbin; Long, Lynn E



Effect of Calcium Chloride on the Permeation of the Cryoprotectant Dimethyl Sulfoxide to Japanese Whiting Sillago japonica Embryos  

NASA Astrophysics Data System (ADS)

Cryopreservation of fish eggs and embryos is a highly desired tool to promote aquaculture production and fisheries resource management, but it is still not technically feasible. The failure to develop successful cryopreservation protocols for fish embryos is largely attributed to poor cryoprotectant permeability. The purpose of this study was to test the effectiveness of CaCl2 to enhance cryoprotectant uptake by fish embryos. In this study, embryos (somites and tail elongation stages) of Japanese whiting Sillago japonica were exposed to 10 and 15% dimethyl sulfoxide (DMSO) in artificial sea water (ASW) or a solution of 0.125M CaCl2 in distilled water for 20 min at 24C. The toxicity of all solutions was estimated from the hatching rates of the embryos and High Performance Liquid Chromatography was used to determine the amount of DMSO taken up during impregnation. The results showed that DMSO incorporation into the embryos was greatly (50%) enhanced in the presence of CaCl2 compared to ASW. CaCl2 itself was not toxic to the embryos but, probably as a result of the enhanced DMSO uptake, caused decreases in survival of about 14-44% relative to ASW. Somites stage embryos were more tolerant than tail elongation ones to DMSO both as ASW and CaCl2 solutions. The use of CaCl2 as a vehicle for DMSO impregnation could be a promising aid for the successful cryopreservation of fish embryos.

Rahman, Sk. Mustafizur; Majhi, Sullip Kumar; Suzuki, Toru; Strussmann, Carlos Augusto; Watanabe, Manabu


Part I. Interaction of Calcium and Copper-Calcium Alloy with Electrolyte  

NASA Astrophysics Data System (ADS)

This paper describes the interaction between calcium and molten CaCl2 and the solubility of calcium in this melt, depending on the calcium content in the copper-calcium alloy that comes in contact with the molten CaCl2. The negative influence of the dissolved calcium on the current efficiency was verified. The negative effects of moisture and CaO impurities on the calcium current efficiency were demonstrated. The dependence of the current efficiency and the purity of the metal obtained by the electrolysis conditions were studied in a laboratory electrolyzer (20 to 80 A).

Zaikov, Yurii P.; Batukhtin, Victor P.; Shurov, Nikolay I.; Ivanovskii, Leonid E.; Suzdaltsev, Andrey V.



Calcium-activated chloride current expression in axotomized sensory neurons: what for?  


Calcium-activated chloride currents (CaCCs) are activated by an increase in intracellular calcium concentration. Peripheral nerve injury induces the expression of CaCCs in a subset of adult sensory neurons in primary culture including mechano- and proprioceptors, though not nociceptors. Functional screenings of potential candidate genes established that Best1 is a molecular determinant for CaCC expression among axotomized sensory neurons, while Tmem16a is acutely activated by inflammatory mediators in nociceptors. In nociceptors, such CaCCs are preferentially activated under receptor-induced calcium mobilization contributing to cell excitability and pain. In axotomized mechano- and proprioceptors, CaCC activation does not promote electrical activity and prevents firing, a finding consistent with electrical silencing for growth competence of adult sensory neurons. In favor of a role in the process of neurite growth, CaCC expression is temporally correlated to neurons displaying a regenerative mode of growth. This perspective focuses on the molecular identity and role of CaCC in axotomized sensory neurons and the future directions to decipher the cellular mechanisms regulating CaCC during neurite (re)growth. PMID:22461766

Boudes, Mathieu; Scamps, Frdrique



Removal of uranium and gross radioactivity from coal bottom ash by CaCl2 roasting followed by HNO3 leaching.  


A roast-leach method using CaCl2 and HNO3 to remove uranium and gross radioactivity in coal bottom ash was investigated. Heat treatment of the ash with 100% CaCl2 (900C, 2h) significantly enhanced uranium leachability (>95%) compared with direct acid-leaching (22.6-25.5%). The removal efficiency of uranium and gross radioactivity increased steeply with increasing CaCl2 content, from 10% to 50%, and a HNO3 leaching time from 5min to 1h, but remained nearly constant or decreased slightly with increasing CaCl2 dosage >50% or acid-leaching time >1h. The majority of the uranium (87.3%), gross ? (92.9%) and gross ? (84.9%) were removed under the optimized roast-leach conditions (50% CaCl2, 1M HNO3 leaching for 1h). The mineralogical characteristics of roasted clinker indicated that molten CaCl2 promoted the incorporation of Ca into silica and silicates and resulted in its progressive susceptibility to acid attack. Uranium and other radionuclides, most likely present in the form of silicates or in association with miscellaneous silicates in the highest density fraction (>2.5gmL(-1)), were probably leached out as the result of the acid decomposition of newly formed "gelatinizing silicates". PMID:24922094

Lei, Xuefei; Qi, Guangxia; Sun, Yinglong; Xu, Hui; Wang, Yi



Long-Term Corrosion Behavior of Alloy 22 in 5M CaCl2 at 120 C  

SciTech Connect

In conditions where tight crevices exist in hot chloride containing solutions Alloy 22 may suffer crevice corrosion. The occurrence (or not) of crevice corrosion in a given environment (e.g, salt concentration and temperature), is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}). This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of creviced Alloy 22 specimens in 5 M calcium chloride (CaCl{sub 2}) at 120 C. Tested specimens included non-creviced rods and multiple creviced assemblies (MCA) both non-welded (wrought) and welded. Results show that Alloy 22 suffers crevice corrosion under the open circuit conditions in the aerated hot CaCl{sub 2} brine. However, after more than a year of immersion the propagation of crevice corrosion was not significant. The general corrosion rate decreased or remained unchanged as the immersion time increased. For rods and MCA specimens, the corrosion rate was lower than 100 nm/year after more than a year immersion time.

J.C. Estill; G.A. Hust; K.J. Evans; M.L. Stuart; R.B. Rebak



Long-Term Corrosion Behavior of Alloy 22 in 5 M CaCl2 at 120?C  

SciTech Connect

In conditions where tight crevices exist in hot chloride containing solutions Alloy 22 may suffer crevice corrosion. The occurrence (or not) of crevice corrosion in a given environment (e.g. salt concentration and temperature), is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}). This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of creviced Alloy 22 specimens in 5 M calcium chloride (CaCl{sub 2}) at 120 C. Tested specimens included non-creviced rods and multiple creviced assemblies (MCA) both non-welded (wrought) and welded. Results show that Alloy 22 suffers crevice corrosion under the open circuit conditions in the aerated hot CaCl{sub 2} brine. However, after more than a year immersion the propagation of crevice corrosion was not significant. The general corrosion rate decreased or remained unchanged as the immersion time increased. For rods and MCA specimens, the corrosion rate was lower than 100 nm/year after more than a year immersion time.

Estill, J C; Hust, G A; Evans, K J; Stuart, M L; Rebak, R B



Irradiation D values of Salmonella spp. in diced tomatoes dipped in 1% calcium chloride.  


Outbreaks of salmonellosis have been associated with eating raw domestic tomatoes. In this study, we examined the efficiency of combined irradiation and a 1% calcium chloride dip to reduce the population of Salmonella enterica strains on diced tomatoes. Tomatoes were contaminated with nalidixic acid-resistant strains of S. Hartford, S. Montevideo, or a mixture of 5 strains (S. Hartford, S. Montevideo, S. Poona, S. Michigan, S. Gaminara). We irradiated tomatoes at various doses up to 0.9 kGy from an electron beam source to conduct a D-value study (decimal reduction time required to eliminate 90% of the organism). Surviving Salmonella populations were detected by standard and recovery plating methods. D-value results ranged from 0.26 to 0.39 kGy, indicating that a 5 log(10) CFU/g reduction in Salmonella spp. in diced tomatoes would require a dose of 1.3-1.95 kGy. PMID:17378712

Prakash, Anuradha; Johnson, Nicole; Foley, Denise



Effect of calcium chloride on the isobaric vapor-liquid equilibrium of 1-propanol + water  

SciTech Connect

The effect of calcium chloride at salt mole fractions from 0.02 to saturation on the vapor-liquid equilibrium (VLE) of 1-propanol + water has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited a salting-out effect of the alcohol over the whole range of liquid composition, the azeotrope being eliminated at salt mole fractions greater than 0.080. A liquid phase splitting into two immiscible liquid phases on the whole range of salt concentration and over a liquid range of about 0.01--0.54 1-propanol mole fraction (salt-free basis) was observed. The results were compared with the values predicted from the extended UNIQUAC models of Sander et al. and Macedo et al. and the modified UNIFAC group-contribution model of Kikic et al.

Iliuta, M.C.; Thyrion, F.C. [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.] [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.; Landauer, O.M. [Univ. Politehnica Bucharest (Romania)] [Univ. Politehnica Bucharest (Romania)



Effects of chloride, calcium, and dissolved organic carbon on silver toxicity: Comparison between rainbow tout and fathead minnows  

Microsoft Academic Search

The effects of independently altering chloride, calcium, and dissolved organic carbon (DOC) on the toxicity of silver were compared between rainbow trout (Oncorhynchus mykiss) and fathead minnows (Pimephales promelas). The 96-h median lethal concentration toxicity tests for both species were performed under the same conditions, within the same containers. In addition, the effect of altering [Cl⁻] on silver-induced perturbations to

Nicolas R. Bury; Fernando Galvez; Chris M. Wood



Boat pressure washing wastewater treatment with calcium oxide and/or ferric chloride.  


The aim of this study was to investigate the efficiency of (1) chemical precipitation by calcium oxide, (2) coagulation/flocculation by ferric chloride (FC), and (3) the combination these two methods in reducing the toxicity of wastewater generated by boat pressure washing. All three methods gave satisfactory results in the removal of colour, turbidity, Cr, Fe, Cu, Zn, and Pb. The concentrations of heavy metals were lowered below national limits with 1 g of CaO, 2.54 mg of Fe3+ in the form of FeCl3x6H2O, and the combination of 0.25 g of CaO and 5.08 mg of Fe3+ per 50 mL of wastewater. Both CaO (1.50 g per 50 mL of wastewater) and FC proved efficient, but their combination yielded a significantly better performance: 99.41 %, 100.00 %, 97.87 %, 99.09 %, 99.90 %, 99.46 % and 98.33 % for colour, turbidity, Cr, Fe, Cu, Zn, and Pb respectively. For colour, Cr, Cu, Zn, and Pb removal efficiencies increased in the following order: FCcalcium oxide followed by ferric chloride is efficient, cost-effective, and user-friendly. PMID:22450202

Ore?anin, Vinja; Kollar, Robert; Na?, Karlo; Mikeli?, Ivanka Lovren?i?; Mikuli?, Nenad



[Calcium-dependent chloride channels in plasma membrane of oocytes from toad, Bufo bufo gargarizans].  


In this paper, membrane current properties of the fully-grown oocytes from toad, Bufo bufo gargarizans, were studied by using two-microelectrode voltage clamp technique. Axion of adult female toad was destroyed, and then ovarian lobes containing oocytes in stage I to VI were removed and incubated in Ca(2+)-free ND96 solution with collagenase (1.5 mg/ml) for 1 h. Subsequently, the oocytes were washed in Ca(2+)-free ND96 solution for 10 min to completely remove the follicular layer. For the experiments only the oocytes in stage V and VI were selected and used during 1 to 5 d. The membrane was depolarized from a holding potential of -80 mV to +60 mV in 10 mV step. It was found that a sustained outward current was elicited by depolarization. Potassium channel blockers (tetraethylammonium chloride, TEA, 10 mmol/L and 4-aminopyridine, 4-AP, 10 mmol/L) reduced the outward current to (23.4+/-0.72)% of the maximum. However, further addition of chloride channel blocker (5-nitro-2, 3-phenypropylamino benzoate, NPPB, 30 micromol/L) could almost completely block the outward current to (2.1+/-0.08)% of the maximum. In the presence of TEA and 4-AP, removal of extracellular Ca(2+) or adding verapamil (40 micromol/L), could also reduce the outward current to (2.2+/-0.04) % and (3.1+/-0.15) % of the maximum, respectively. It is concluded that calcium-dependent chloride channels exist in plasma membrane of Bufo bufo gargarizans oocytes, besides potassium channels. PMID:17041732

Pi, Yan-Li; Ma, Ji-Hua; Zhang, Pei-Hua; Duan, Jing-Jing



A Cyclic GMP-dependent Calcium-activated Chloride Current in Smooth-muscle Cells from Rat Mesenteric Resistance Arteries  

PubMed Central

We have previously demonstrated the presence of a cyclic GMP (cGMP)-dependent calcium-activated inward current in vascular smooth-muscle cells, and suggested this to be of importance in synchronizing smooth-muscle contraction. Here we demonstrate the characteristics of this current. Using conventional patch-clamp technique, whole-cell currents were evoked in freshly isolated smooth-muscle cells from rat mesenteric resistance arteries by elevation of intracellular calcium with either 10 mM caffeine, 1 ?M BAY K8644, 0.4 ?M ionomycin, or by high calcium concentration (900 nM) in the pipette solution. The current was found to be a calcium-activated chloride current with an absolute requirement for cyclic GMP (EC50 6.4 ?M). The current could be activated by the constitutively active subunit of PKG. Current activation was blocked by the protein kinase G antagonist Rp-8-Br-PET-cGMP or with a peptide inhibitor of PKG, or with the nonhydrolysable ATP analogue AMP-PNP. Under biionic conditions, the anion permeability sequence of the channel was SCN? > Br? > I? > Cl? > acetate > F? >> aspartate, but the conductance sequence was I? > Br? > Cl? > acetate > F? > aspartate = SCN?. The current had no voltage or time dependence. It was inhibited by nickel and zinc ions in the micromolar range, but was unaffected by cobalt and had a low sensitivity to inhibition by the chloride channel blockers niflumic acid, DIDS, and IAA-94. The properties of this current in mesenteric artery smooth-muscle cells differed from those of the calcium-activated chloride current in pulmonary myocytes, which was cGMP-independent, exhibited a high sensitivity to inhibition by niflumic acid, was unaffected by zinc ions, and showed outward current rectification as has previously been reported for this current. Under conditions of high calcium in the patch-pipette solution, a current similar to the latter could be identified also in the mesenteric artery smooth-muscle cells. We conclude that smooth-muscle cells from rat mesenteric resistance arteries have a novel cGMP-dependent calcium-activated chloride current, which is activated by intracellular calcium release and which has characteristics distinct from other calcium-activated chloride currents.

Matchkov, Vladimir V.; Aalkjaer, Christian; Nilsson, Holger



The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500??C  

USGS Publications Warehouse

We determined vapor-liquid relations (P-T-x) and derived critical parameters for the system CaCl2-H2O from 380-500??C. Results show that the two-phase region of this system is extremely large and occupies a significant portion of the P-T space to which circulation of fluids in the Earth's crust is constrained. Results also show the system generates significant amounts of HCl (as much as 0.1 mol/kg) in the vapor phase buffered by the liquid at surprisingly high pressures (???230 bars at 380??C, <580 bars at 500??C), presumably by hydrolysis of CaCl2: CaCl2 + 2H2O = Ca(OH)2 + 2HCl. We interpret the abundance of HCl in the vapor as due to its preference for the vapor phase, and by the preference of Ca(OH)2 for either the liquid phase or solid. The recent recognition of the abundance of CaCl2 in deep brines of the Earth's crust and their hydrothermal mobilization makes the hydrolysis of CaCl2 geologically important. The boiling of Ca-rich brines produces abundant HCl buffered by the presence of the liquid at moderate pressures. The resultant Ca(OH)2 generated by this process reacts with silicates to form a variety of alteration products, such as epidote, whereas the vapor produces acid-alteration of rocks through which it ascends.

Bischoff, J. L.; Rosenbauer, R. J.; Fournier, R. O.



Attenuated responses to endothelin-1, KCl and CaCl2, but not noradrenaline, of aortae from rats with streptozotocin-induced diabetes mellitus.  

PubMed Central

1. This study investigated the responsiveness to vasoconstrictor agents (including endothelin-1, ET-1) of aortic rings from rats with two-week streptozotocin (STZ, 60 mg kg-1, i.v.)-induced diabetes and vehicle-treated control rats. The basal tension was 10 g, which was estimated to be more physiological than the tension of 1-2 g that has been previously used for most studies of aortic rings from diabetic rats. 2. Maximum responses to ET-1 (0.13-18 nM), KCl (2-20 mM) or CaCl2 (10 microM-10 mM) were reduced in aortae from STZ-treated rats compared to those from control rats. Such reductions were still evident after removal of the endothelium. 3. Responses to noradrenaline (NA, 0.1 nM-26 microM) of aortae from STZ-treated rats were not significantly different from responses of aortae of control rats. 4. Removal of endothelium resulted in a significant reduction in the EC50 values for NA of rings from both STZ-treated rats (6.90 +/- 0.13 and 8.17 +/- 0.35 (-log M) with and without endothelium, respectively, n = 5) and control rats (6.90 +/- 0.15 and 8.37 +/- 0.44 (-log M) with and without endothelium, respectively, n = 5). 5. In calcium-free medium (with 1 mM EGTA), responses to NA and ET-1 were reduced compared with those in normal Krebs solution and maximum responses were less in rings from STZ-treated compared with control rats. 6. Indomethacin (5 microM) did not prevent the reduced maximum responsiveness to ET-1 in rings from STZ-treated rats compared with those from controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Fulton, D. J.; Hodgson, W. C.; Sikorski, B. W.; King, R. G.



Interfacial tension between CO 2 and brine (NaCl + CaCl 2) at elevated pressures and temperatures: The additive effect of different salts  

NASA Astrophysics Data System (ADS)

An extensive laboratory study was conducted to measure the interfacial tension (IFT) between CO 2 and brine consisting in equal molal concentrations of NaCl and CaCl 2. The experiments were repeated at various pressures, temperatures and salinities that are representative of conditions prevailing during CO 2 storage in deep saline aquifers. The dependence of CO 2/brine IFT on pressure and temperature is similar to that previously reported for the systems: CO 2/NaCl solution and CO 2/CaCl 2 solution. CO 2/brine IFT increases linearly with water salinity and the magnitude of this increase was found equal to the sum of the individual CO 2/NaCl solution and CO 2/CaCl 2 solution IFT increments, indicating a strong additive effect on IFT when the brine is composed of various salts.

Aggelopoulos, C. A.; Robin, M.; Vizika, O.



Improving NaCl resistance of red-osier dogwood: role of CaCl 2 and CaSO 4  

Microsoft Academic Search

The influence of Ca2+ salts on the resistance of red-osier dogwood (Cornus sericea) seedlings to salinity was investigated. Red-osier dogwood seedlings were exposed to 5 and 10mM of CaCl2 or CaSO4 in the presence or absence of 50mM NaCl for 40days in a controlled environment. Seedlings exposed to CaCl2 and CaSO4 recovered from NaCl-induced transpiration reduction after 20days at a

Sylvie Renault; Maha Affifi



Cloning and characterization of a calcium-activated chloride channel in rat uterus.  


In a search for genes involved in regulation of uterine contractility, we cloned a novel calcium-activated chloride channel gene, named rat Clca4, from pregnant rat uterus. The gene shares approximately 83% and 70% nucleotide homology with mouse Clca6 and human CLCA4, respectively, and was expressed primarily in rat uterus. The transcripts were upregulated at Gestational Day 22 (prior to parturition), implying a functional involvement in parturition. Western blot analysis showed that rat CLCA4 protein was present in uterus, lung, and heart, but not in any other tissues examined. Confocal microscopy revealed that rat CLCA4 is localized in cell membrane and could not be removed by alkaline or PBS washing. Transient transfection of rat CLCA4-enhanced green fluorescent protein in Chinese hamster ovary cells resulted in production of characteristic Cl(-) currents that could be activated by Ca(2+) and ionomycin but inhibited by niflumic acid, a CLCA-channel blocker. The identification and characterization of rat Clca4 help decipher the contribution of Ca(2+)-activated Cl(-) conductance in myometrial contractility. PMID:19144963

Song, Junfang; Zhang, Xiaojuan; Qi, Zhi; Sun, Gang; Chi, Shaopeng; Zhu, Zhaohui; Ren, Jiangong; Qiu, Zhaojun; Liu, Ka; Myatt, Leslie; Ma, Runlin Z



Effect of Calcium Sulphate Nanoparticles on Fusion, Mechanical and Thermal Behaviour Polyvinyl Chloride (pvc)  

NASA Astrophysics Data System (ADS)

Calcium Sulphate [CaSO4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO4 (micro and nano) and the matrix poly (vinyl chloride) (PVC) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer was used for preparation and evaluation of fusion behaviour of composites of different formulations. The effect of nano and micro-CaSO4 content on the structure and properties of composites was studied. The nanostructures and dispersion were studied by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The mechanical and thermal properties of PVC/ micro and nano-CaSO4 composites were characterized using Universal Testing Machine (UTM) and Thermo Gravimetric Analyzer (TGA). From the results of WAXD and SEM the flocculation of CaSO4 nanoparticles were observed on the surfaces of PVC matrix. The thermal analysis results showed that the first thermal degradation onset (T onset) of PVC/nano-CaSO4 composites for 1 wt. % of filler were higher as compared with corresponding microcomposites and pristine PVC. However, the tensile strength was decreasing with increasing filler content while, it shows increment in magnitude at 1 and 2 wt. % of nano-CaSO4 as compared with corresponding micro-CaSO4 as well as pristine PVC.

Patil, C. B.; Shisode, P. S.; Kapadi, U. R.; Hundiwale, D. G.; Mahulikar, P. P.


Expression cloning of TMEM16A as a calcium-activated chloride channel subunit  

PubMed Central

SUMMARY Calcium-activated chloride channels (CaCCs) are major regulators of sensory transduction, epithelial secretion and smooth muscle contraction. Other crucial roles of CaCCs include action potential generation in Characean algae and prevention of polyspermia in frog oocyte membrane. None of the known molecular candidates share properties characteristic of most CaCCs in native cells. Using Axolotl oocytes as expression system, we have identified TMEM16A as the Xenopus oocyte CaCC. The TMEM16 family of transmembrane proteins with unknown function is conserved among eukaryotes, with family members linked to tracheomalacia (mouse TMEM16A), gnathodiaphyseal dysplasia (human TMEM16E), aberrant X segregation (a Drosophila TMEM16 family member) and increased sodium tolerance (yeast TMEM16). Moreover, mouse TMEM16A and TMEM16B yield CaCCs in Axolotl oocytes and mammalian HEK293 cells, and recapitulate the broad CaCC expression. The identification of this new family of ion channels may help the development of CaCC modulators for treating diseases including hypertension and cystic fibrosis.

Schroeder, Bjorn Christian; Cheng, Tong; Jan, Yuh Nung; Jan, Lily Yeh



Scopolamine and hyoscyamine production by hairy root cultures of Brugmansia candida: influence of calcium chloride, hemicellulase and theophylline  

Microsoft Academic Search

CaCl2 (50 mM) and hemicellulase (0.5Umg-1) increased the intracellular accumulation (60250%), release (60200%) and production (45200%) of hyoscyamine and scopolamine in hairy roots of Brugmansia candida. Theophylline (0.25mM), alone or in combination with hemicellulase, was ineffective in increasing hyoscyamine and scopolamine production.

S. I. Pitta-Alvarez; T. C. Spollansky; A. M. Giulietti



Mechanism of the synergic effects of calcium chloride and electroporation on the in vitro enhanced skin permeation of drugs  

Microsoft Academic Search

We have already reported the substantial synergic effects of CaCl2 and electroporation (EP) on in vitro skin permeation of calcein and FITC dextrans. In the present paper, we investigated the mechanisms for these effects by considering changes in lamellar structure and barrier recovery time of the biggest skin barrier, the stratum corneum, by this combined treatment. The change in skin

Yoshihiro Tokudome; Kenji Sugibayashi



Small-molecule activators of TMEM16A, a calcium-activated chloride channel, stimulate epithelial chloride secretion and intestinal contraction  

PubMed Central

TMEM16A (ANO1) is a calcium-activated chloride channel (CaCC) expressed in secretory epithelia, smooth muscle, and other tissues. Cell-based functional screening of ?110,000 compounds revealed compounds that activated TMEM16A CaCC conductance without increasing cytoplasmic Ca2+. By patch-clamp, N-aroylaminothiazole activators (Eact) strongly increased Cl? current at 0 Ca2+, whereas tetrazolylbenzamide potentiators (Fact) were not active at 0 Ca2+ but reduced the EC50 for Ca2+-dependent TMEM16A activation. Of 682 analogs tested, the most potent activator (Eact) and potentiator (Fact) produced large and more sustained CaCC Cl? currents than general agonists of Ca2+ signaling, with EC50 36 ?M and Cl? conductance comparable to that induced transiently by Ca2+-elevating purinergic agonists. Analogs of activators were identified that fully inhibited TMEM16A Cl? conductance, providing further evidence for direct TMEM16A binding. The TMEM16A activators increased CaCC conductance in human salivary and airway submucosal gland epithelial cells, and IL-4 treated bronchial cells, and stimulated submucosal gland secretion in human bronchi and smooth muscle contraction in mouse intestine. Small-molecule, TMEM16A-targeted activators may be useful for drug therapy of cystic fibrosis, dry mouth, and gastrointestinal hypomotility disorders, and for pharmacological dissection of TMEM16A function.Namkung, W., Yao, Z., Finkbeiner, W. E., Verkman, A. S. Small-molecule activators of TMEM16A, a calcium-activated chloride channel, stimulate epithelial chloride secretion and intestinal contraction.

Namkung, Wan; Yao, Zhen; Finkbeiner, Walter E.; Verkman, A. S.



Corrosion Effects of Calcium Chloride Injection for Mercury Control on the Pollution Control Equipment  

SciTech Connect

In response to the Clean Air Mercury Rule (CAMR) of 2005, Black Hills Power (BHP) initiated testing of a calcium chloride (CaCl{sub 2}) injection method in their Wygen 1 (Gillette, WY) coal-fired power plant to help lower mercury emissions. In 2006, Babcock & Wilcox (B&W) was contracted to test their CaCl{sub 2} technology in-situ by adding a CaCl{sub 2} solution onto the raw, pre-pulverized coal during normal operation of Wygen 1. Follow-up tests were conducted by BHP in 2007. Data were collected from these two time periods and analyzed by a collaborative investigation team from Western Research Institute (WRI) and the University of Wyoming (UW) to see if there were any effects on the current air pollution control systems. During a CaCl{sub 2} injection period in 2007, corrosion was monitored in the flue and recycle ash system by placing corrosion coupons in strategic locations to test if corrosion was enhanced by the CaCl{sub 2} injection. While the CaCl{sub 2} produced a reduction in stack mercury levels, there was some evidence of beneficial impacts on the removal of SO{sub 2} from the flue gas during CaCl{sub 2} injection. Data on NOx remained inconclusive. It was also discovered that corrosion was enhanced significantly in the Spray Drier Absorber (SDA) vessel and corresponding outlet ductwork during CaCl{sub 2} injections. Further studies are being carried out in the field and lab to better understand the corrosive effects of CaCl{sub 2} to help formulate operation controls to manage the increased corrosion rates.

Vijay Sethi; M.P. Sharma



Mechanism of the synergic effects of calcium chloride and electroporation on the in vitro enhanced skin permeation of drugs.  


We have already reported the substantial synergic effects of CaCl(2) and electroporation (EP) on in vitro skin permeation of calcein and FITC dextrans. In the present paper, we investigated the mechanisms for these effects by considering changes in lamellar structure and barrier recovery time of the biggest skin barrier, the stratum corneum, by this combined treatment. The change in skin lamellar structure was evaluated by lipid mobility in the stratum corneum using ATR-FTIR, calcein release from stratum corneum-lipid liposomes (SCLL), in vitro skin permeation of calcein and transepidermal water loss (TEWL). The ATR-FTIR measurement, in vitro skin permeation and changes in TEWL were also used for examining the barrier recovery time. The C-H stretching band of skin lipids produced with EP was blue-shifted when compared to that without EP. Asymmetric C-H stretching was highest with EP in CaCl(2) solution. Little release of calcein was observed from SCLL without EP, whereas higher releases were observed after EP with or without NaCl or CaCl(2). Particularly high calcein release (>20%) was observed over 60 min with EP in CaCl(2) solution. The in vitro permeation study of calcein was conducted through excised hairless rat skin that was pretreated with EP before skin excision. Permeation rate was highest in skin excised immediately after in vivo EP, and this rate decreased with time after EP treatment. TEWL recovered to control levels within 2 h after EP in distilled water or NaCl solution, whereas high TEWL was maintained after EP in CaCl(2) solution. These results suggest that at least lamellar destruction of stratum corneum must be related to the enhanced skin permeation of drugs by the combination of CaCl(2) and EPF. On the other hand, a prolonged enhancing effect on the skin permeation of calcein by this combination may be due to a high lamellar destruction and/or delayed barrier repair of stratum corneum. PMID:14980775

Tokudome, Yoshihiro; Sugibayashi, Kenji



Calcium-activated chloride channel ANO1 promotes breast cancer progression by activating EGFR and CAMK signaling.  


The calcium-activated chloride channel anoctamin 1 (ANO1) is located within the 11q13 amplicon, one of the most frequently amplified chromosomal regions in human cancer, but its functional role in tumorigenesis has remained unclear. The 11q13 region is amplified in ?15% of breast cancers. Whether ANO1 is amplified in breast tumors, the extent to which gene amplification contributes to ANO1 overexpression, and whether overexpression of ANO1 is important for tumor maintenance have remained unknown. We have found that ANO1 is amplified and highly expressed in breast cancer cell lines and primary tumors. Amplification of ANO1 correlated with disease grade and poor prognosis. Knockdown of ANO1 in ANO1-amplified breast cancer cell lines and other cancers bearing 11q13 amplification inhibited proliferation, induced apoptosis, and reduced tumor growth in established cancer xenografts. Moreover, ANO1 chloride channel activity was important for cell viability. Mechanistically, ANO1 knockdown or pharmacological inhibition of its chloride-channel activity reduced EGF receptor (EGFR) and calmodulin-dependent protein kinase II (CAMKII) signaling, which subsequently attenuated AKT, v-src sarcoma viral oncogene homolog (SRC), and extracellular signal-regulated kinase (ERK) activation in vitro and in vivo. Our results highlight the involvement of the ANO1 chloride channel in tumor progression and provide insights into oncogenic signaling in human cancers with 11q13 amplification, thereby establishing ANO1 as a promising target for therapy in these highly prevalent tumor types. PMID:23431153

Britschgi, Adrian; Bill, Anke; Brinkhaus, Heike; Rothwell, Christopher; Clay, Ieuan; Duss, Stephan; Rebhan, Michael; Raman, Pichai; Guy, Chantale T; Wetzel, Kristie; George, Elizabeth; Popa, M Oana; Lilley, Sarah; Choudhury, Hedaythul; Gosling, Martin; Wang, Louis; Fitzgerald, Stephanie; Borawski, Jason; Baffoe, Jonathan; Labow, Mark; Gaither, L Alex; Bentires-Alj, Mohamed



Poly(?-glutamic acid)/Silica Hybrids with Calcium Incorporated in the Silica Network by Use of a Calcium Alkoxide Precursor.  


Current materials used for bone regeneration are usually bioactive ceramics or glasses. Although they bond to bone, they are brittle. There is a need for new materials that can combine bioactivity with toughness and controlled biodegradation. Sol-gel hybrids have the potential to do this through their nanoscale interpenetrating networks (IPN) of inorganic and organic components. Poly(?-glutamic acid) (?-PGA) was introduced into the sol-gel process to produce a hybrid of ?-PGA and bioactive silica. Calcium is an important element for bone regeneration but calcium sources that are used traditionally in the sol-gel process, such as Ca salts, do not allow Ca incorporation into the silicate network during low-temperature processing. The hypothesis for this study was that using calcium methoxyethoxide (CME) as the Ca source would allow Ca incorporation into the silicate component of the hybrid at room temperature. The produced hybrids would have improved mechanical properties and controlled degradation compared with hybrids of calcium chloride (CaCl2 ), in which the Ca is not incorporated into the silicate network. Class II hybrids, with covalent bonds between the inorganic and organic species, were synthesised by using organosilane. Calcium incorporation in both the organic and inorganic IPNs of the hybrid was improved when CME was used. This was clearly observed by using FTIR and solid-state NMR spectroscopy, which showed ionic cross-linking of ?-PGA by Ca and a lower degree of condensation of the Si species compared with the hybrids made with CaCl2 as the Ca source. The ionic cross-linking of ?-PGA by Ca resulted in excellent compressive strength and reduced elastic modulus as measured by compressive testing and nanoindentation, respectively. All hybrids showed bioactivity as hydroxyapatite (HA) was formed after immersion in simulated body fluid (SBF). PMID:24838668

Poologasundarampillai, Gowsihan; Yu, Bobo; Tsigkou, Olga; Wang, Daming; Romer, Frederik; Bhakhri, Vineet; Giuliani, Finn; Stevens, Molly M; McPhail, David S; Smith, Mark E; Hanna, John V; Jones, Julian R



The structure, dynamics and solvation mechanisms of ions in water from long time molecular dynamics simulations: a case study of CaCl2(aq) aqueous solutions  

Microsoft Academic Search

Systematic long time (520 ns) molecular dynamics (MD) simulations have been carried out to study the structural and dynamical properties of CaCl2 aqueous solutions over a wide range of concentrations (?9.26 m) in this study. Our simulations reveal totally different structural characteristics of those yielded from short time (?1 ns) MD simulations [A.A. Chialvo and J.M. Simonson, J. Chem. Phys.

Mingyan Li; Zhenhao Duan; Zhigang Zhang; Chi Zhang; John Weare



Comparison of a hot water and cold 0.01 M Cacl2 extraction procedures for the determination of boron in soil  

Microsoft Academic Search

In 100 different soils, hot (100C) water extractable boron was determined and the results were compared with boron data after extraction of the same soil samples with cold (20C) 0.01 M CaCl2. Since the boron concentrations in cold soil extracts are too low for direct determination, the extracted boron was converted into BF4? and subsequently extracted with a liquid anion

I. Novozamsky; L. L. Barrera; V. J. G. Houba; J. J. van der Lee; R. van Eck



Calcium taste preferences: Genetic analysis and genome screen of C57BL/6J x PWK/PhJ hybrid mice  

PubMed Central

To characterize the genetic basis of voluntary calcium consumption, we tested C57BL/6J mice (B6; with low avidity for calcium), PWK/PhJ mice (PWK; with high avidity for calcium) and their F1 and F2 hybrids. All mice received a series of 96-h two-bottle preference tests with a choice between water and the following: 50 mM CaCl2, 50 mM calcium lactate, 50 mM MgCl2, 100 mM KCl, 100 mM NH4Cl, 100 mM NaCl, 5 mM citric acid, 30 ?M quinine hydrochloride, and 2 mM saccharin. Most frequency distributions of the parental and F1 but not F2 groups were normally distributed, and there were few sex differences. Reciprocal cross analysis revealed that B6 PWK F1 mice had a nonspecific elevation of fluid intake relative to PWK B6 F1 mice. In the F2 mice, trait correlations were clustered among the divalent salts and the monovalent chlorides. A genome screen involving 116 short tandem repeat markers revealed 30 QTLs, of which six involved consumption of calcium chloride or lactate. The results demonstrate pleiotropic controls of calcium and magnesium consumption that are distinct from those controlling consumption of monovalent chlorides or exemplars of the primary taste qualities.

Tordoff, Michael G.; Reed, Danielle R.; Shao, Hongguang



CO 2/CaCl 2 solution interfacial tensions under CO 2 geological storage conditions: Influence of cation valence on interfacial tension  

NASA Astrophysics Data System (ADS)

The effectiveness of CO 2 storage in deep saline aquifers and hydrocarbon reservoirs is governed, among other factors, by the interfacial tension between the injected CO 2 and formation water (brine). Experimental data on CO 2/water and CO 2/NaCl solution have revealed that the interfacial tension depends on the pressure, temperature and water salinity. However, there is still a lack of data for other salts (such as MgCl 2 and CaCl 2) which are also present in aquifers and carbonate reservoirs. In the present work, the interfacial tension (IFT) of the system CO 2/CaCl 2 solution is measured under pressures, temperatures and salinities which are relevant to storage conditions. The evolution of CO 2/CaCl 2 solution IFT with pressure and temperature is similar to that reported for CO 2/water and CO 2/NaCl solution systems and increases linearly with salinity. When correlating the measured IFT with the salt concentration, it looks that the IFT increase, due to salt concentration, is proportional to the cation valence.

Aggelopoulos, C. A.; Robin, M.; Perfetti, E.; Vizika, O.



Evaluation of the effect of CaCl2 and alginate concentrations and hardening time on the characteristics of Lactobacillus acidophilus loaded alginate beads using response surface analysis  

PubMed Central

Purpose: This article describes preparation and characterization of beads of alginate containing probiotic bacteria of Lactobacillus acidophilus DMSZ20079. Methods: Fourteen formulations using different alginate (ALG) and CaCl2 concentrations as well as hardening times were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology, encapsulation efficiency and bacterial viabilities in acid (pH 1.8, 2 hours) condition. Results: The results showed that spherical beads with narrow size distribution ranging from 1.320.04 to 1.700.07 mm were achieved with encapsulation efficiency higher than 98%. Surface response analysis revealed that alginate concentration was the important factor for the size, shape and encapsulation efficiency of prepared beads. Furthermore, survived bacteria after acid exposure in all prepared beads (63-83%) were significantly higher than those of untreated cells (39%) and enhanced by increasing alginate concentration. Surface response analysis revealed that the effect of all three factors of alginate and CaCl2 concentrations as well as hardening times were significant in acid viability, however alginate concentration played the most important role according to its regression coefficient. Conclusion: Among alginate and CaCl2 concentrations as well as hardening times, alginate concentration was the most variable in the characteristics of Alginate beads.

Lotfipour, Farzaneh; Mirzaeei, Shahla; Maghsoodi, Maryam



The role of calcium in growth induced by indole-3-acetic acid and gravity in the leaf-sheath pulvinus of oat (Avena sativa)  

NASA Technical Reports Server (NTRS)

Leaf-sheath pulvini of excised segments from oat (Avena sativa L.) were induced to grow by treatment with 10 micromoles indole-3-acetic acid (IAA), gravistimulation, or both, and the effects of calcium, EGTA, and calcium channel blockers on growth were evaluated. Unilaterally applied calcium (10 mM CaCl2) significantly inhibited IAA-induced growth in upright pulvini but had no effect on growth induced by either gravity or gravity plus IAA. Calcium alone had no effect on upright pulvini. The calcium chelator EGTA alone (10 mM) stimulated growth in upright pulvini. However, EGTA had no effect on either IAA- or gravity-induced growth but slightly diminished growth in IAA-treated gravistimulated pulvini. The calcium channel blockers lanthanum chloride (25 mM), verapamil (2.5 mM), and nifedipine (2.5 mM) greatly inhibited growth as induced by IAA (> or = 50% inhibition) or IAA plus gravity (20% inhibition) but had no effect on gravistimulated pulvini. Combinations of channel blockers were similar in effect on IAA action as individual blockers. Since neither calcium ions nor EGTA significantly affected the graviresponse of pulvini, we conclude that apoplastic calcium is unimportant in leaf-sheath pulvinus gravitropism. The observation that calcium ions and calcium channel blockers inhibit IAA-induced growth, but have no effect on gravistimulated pulvini, further supports previous observations that gravistimulation alters the responsiveness of pulvini to IAA.

Brock, T. G.; Burg, J.; Ghosheh, N. S.; Kaufman, P. B.



Effect of calcium source on structure and properties of sol-gel derived bioactive glasses.  


The aim was to determine the most effective calcium precursor for synthesis of sol-gel hybrids and for improving homogeneity of sol-gel bioactive glasses. Sol-gel derived bioactive calcium silicate glasses are one of the most promising materials for bone regeneration. Inorganic/organic hybrid materials, which are synthesized by incorporating a polymer into the sol-gel process, have also recently been produced to improve toughness. Calcium nitrate is conventionally used as the calcium source, but it has several disadvantages. Calcium nitrate causes inhomogeneity by forming calcium-rich regions, and it requires high temperature treatment (>400 C) for calcium to be incorporated into the silicate network. Nitrates are also toxic and need to be burnt off. Calcium nitrate therefore cannot be used in the synthesis of hybrids as the highest temperature used in the process is typically 40-60 C. Therefore, a different precursor is needed that can incorporate calcium into the silica network and enhance the homogeneity of the glasses at low (room) temperature. In this work, calcium methoxyethoxide (CME) was used to synthesize sol-gel bioactive glasses with a range of final processing temperatures from 60 to 800 C. Comparison is made between the use of CME and calcium chloride and calcium nitrate. Using advanced probe techniques, the temperature at which Ca is incorporated into the network was identified for 70S30C (70 mol % SiO(2), 30 mol % CaO) for each of the calcium precursors. When CaCl(2) was used, the Ca did not seem to enter the network at any of the temperatures used. In contrast, Ca from CME entered the silica network at room temperature, as confirmed by X-ray diffraction, (29)Si magic angle spinning nuclear magnetic resonance spectroscopy, and dissolution studies. CME should be used in preference to calcium salts for hybrid synthesis and may improve homogeneity of sol-gel glasses. PMID:23171477

Yu, Bobo; Turdean-Ionescu, Claudia A; Martin, Richard A; Newport, Robert J; Hanna, John V; Smith, Mark E; Jones, Julian R



Application of 1-methylcyclopropene, calcium chloride and calcium amino acid chelate on fresh-cut cantaloupe muskmelon  

Microsoft Academic Search

The objective of this work was to determine the effects of postharvest application of 1-methylcyclopropene (1-MCP) and two calcium salts, applied individually or combined, on firmness and visual quality of fresh-cut muskmelon stored in air, for 18 days. Two sets of fruits, one of them exposed to 1-MCP at 300 nL L -1 , were cut into cubes, dipped in

Francisca Ligia





... calcium. Veggies. You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and ... of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified products, including orange juice, ...


Long-Term Corrosion Behavior of Alloy 22 in 5 M CaCl2 at 120 C.  

National Technical Information Service (NTIS)

In conditions where tight crevices exist in hot chloride containing solutions Alloy 22 may suffer crevice corrosion. The occurrence (or not) of crevice corrosion in a given environment (e.g. salt concentration and temperature), is governed by the values o...

G. A. Hust J. C. Estill K. J. Evans M. L. Stuart R. B. Rebak



Chlorotoxin does not inhibit volume-regulated, calcium-activated and cyclic AMP-activated chloride channels  

PubMed Central

It was the aim of this study to look for a high-affinity and selective polypeptide toxin, which could serve as a probe for the volume-regulated anion channel (VRAC) or the calcium-activated chloride channel (CaCC). We have partially purified chlorotoxin, including new and homologous short chain insectotoxins, from the crude venom of Leiurus quinquestriatus quinquestriatus (Lqq) by means of gel filtration chromatography. Material eluting between 280 and 420?min, corresponding to fractions 1521, was lyophilized and tested on VRAC and CaCC, using the whole-cell patch-clamp technique. We have also tested the commercially available chlorotoxin on VRAC, CaCC, the cystic fibrosis transmembrane conductance regulator (CFTR) and on the glioma specific chloride channel (GCC). VRAC and the correspondent current, ICl,swell, was activated in Cultured Pulmonary Artery Endothelial (CPAE) cells by a 25% hypotonic solution. Neither of the fractions 1621 significantly inhibited ICl,swell (n=45). Ca2+-activated Cl? currents, ICl,Ca, activated by loading T84 cells via the patch pipette with 1??M free Ca2+, were not inhibited by any of the tested fractions (1521), (n=25). Chlorotoxin (625?nM) did neither effect ICl,swell nor ICl,Ca (n=45). The CFTR channel, transiently transfected in COS cells and activated by a cocktail containing IBMX and forskolin, was not affected by 1.2??M chlorotoxin (n=5). In addition, it did not affect currents through GCC. We conclude that submicromolar concentrations of chlorotoxin do not block volume-regulated, Ca2+-activated and CFTR chloride channels and that it can not be classified as a general chloride channel toxin.

Maertens, Chantal; Wei, Lin; Tytgat, Jan; Droogmans, Guy; Nilius, Bernd



The Transition from Proliferation to Differentiation in Colorectal Cancer Is Regulated by the Calcium Activated Chloride Channel A1  

PubMed Central

Breaking the balance between proliferation and differentiation in animal cells can lead to cancer, but the mechanisms maintaining this balance remain largely undefined. The calcium activated chloride channel A1 (CLCA1) is a member of the calcium sensitive chloride conductance family of proteins and is expressed mainly in the colon, small intestine and appendix. We show that CLCA1 plays a functional role in differentiation and proliferation of Caco-2 cells and of intestinal tissue. Caco-2 cells spontaneously differentiate either in confluent culture or when treated with butyrate, a molecule present naturally in the diet. Here, we compared CLCA1 expressional levels between patients with and without colorectal cancer (CRC) and determined the functional role of CLCA1 in differentiation and proliferation of Caco-2 cells. We showed that: 1) CLCA1 and CLCA4 expression were down-regulated significantly in CRC patients; 2) CLCA1 expression was up-regulated in Caco-2 cells induced to differentiate by confluent culture or by treatment with sodium butyrate (NaBT); 3) Knockdown of CLCA1 with siRNA significantly inhibited cell differentiation and promoted cell proliferation in Caco-2 confluent cultures, and 4) In Caco-2 3D culture, suppression of CLCA1 significantly increased cell proliferation and compromised NaBT-induced inhibition of proliferation. In conclusion, CLCA1 may contribute to promoting spontaneous differentiation and reducing proliferation of Caco-2 cells and may be a target of NaBT-induced inhibition of proliferation and therefore a potential diagnostic marker for CRC prognosis.

Liu, Bin; McCaig, Colin D.; Pu, Jin



Remediation of cadmium-contaminated paddy soils by washing with calcium chloride: verification of on-site washing.  


We developed a new, three-step soil-wash method to remediate Cd-contaminated paddy fields. The method comprises (1) chemically washing the field soil with a CaCl2 solution; (2) washing the treated soil with water to eliminate residual Cd and CaCl2; and (3) on-site treatment of wastewater using a portable wastewater treatment system. Cd concentrations in the treated water were below Japan's environmental quality standard (0.01 mg Cd L-1), and the removal of Cd from the exchangeable fraction was 55% and from the acid-soluble fraction 15%. While soil fertility properties were affected by the soil washing, adverse effects were not crucial and could be corrected. The washing had no affect on rice growth, and reduced the average Cd concentration in rice grains by about two-thirds compared to a control plot. These results confirmed the effectiveness of the soil-wash method in remediating Cd-contaminated paddy fields. PMID:17141928

Makino, Tomoyuki; Kamiya, Takashi; Takano, Hiroyuki; Itou, Tadashi; Sekiya, Naoki; Sasaki, Kouta; Maejima, Yuji; Sugahara, Kazuo



Sex- and dose-dependent effects of post-trial calcium channel blockade by magnesium chloride on memory for inhibitory avoidance conditioning.  


Calcium influx through voltage-dependent Ca(2+) channels is critical for many neuronal processes required for learning and memory. Persistent increases in cytosolic intracellular Ca(2+) concentrations in aging neurons are associated with learning impairments, while small transient subcellular changes in intracellular calcium concentrations play critical roles in neural plasticity in young neurons. In the present study, young male and female Fisher 344 Brown Norway (FBN) hybrid rats were administered different doses of magnesium chloride (0.0, 100.0, or 200.0mg/kg, i.p.) following a single inhibitory avoidance training trial. Extracellular magnesium ions can non-specifically block voltage-gated calcium channels, and/or reduce the calcium conductance gated via glutamate and serine's activation of neuronal NMDA receptors. In our study, magnesium chloride dose-dependently enhanced memory compared to controls (significantly increased latency to enter a dark compartment previously paired with an aversive stimulus) when tested 48 h later as compared to controls. A leftward shift in the dose response curve for memory enhancement by magnesium chloride was observed for male compared to female rats. These findings provide further insights into calcium-dependent modulation of aversive memory, and should be considered when assessing the design of effective treatment options for both male and female patients with dementia or other memory problems. PMID:24095881

Wilmott, Lynda A; Thompson, Lucien T



Sequential application of NaHCO3, CaCl2 and Candida oleophila (isolate 13L) affects significantly Penicillum expansum growth and the infection degree in apples.  


The employment of biocontrol agents to restrain postharvest pathogens is an encouraging approach, although, efficacy and consistency are still below those of synthetic pesticides. Up to date, the 'integrated control strategy' seems to be the most promising way to overcome this gap. Here, we report the feasibility to control postharvest decay caused by Penicillium expansum in apples by a 2 min, single or sequential, immersion in water with an antagonistic yeast (Candida oleophila, isolate '13L'), 2% NaHCO3 (SBC) or 1% CaCl2. The treatments were carried out, on appels cv 'Miali' either un-wounded, wounded or wound-pathogen inoculated and then stored at 2 degrees C for 30 d followed by a 6 d simulated marketing period at 20 degrees C or alternatively stored only for 7 d at 20 degrees C. As a general role, the best results were attained when CaCl2 was applied with the yeast or when preceded by the SBC treatment. When the wounding and inoculation took place 24 h before the treatment, the latter application sequence of the two salts was three times more effective compared to the treatment with the sole antagonist, and one time when performed 24 h after the treatment. Interestingly, apples immersed in the sole 2% SBC solution had the highest percentage of decay during storage and when inoculated before moving to the simulated marketing period at 20 degrees C. PMID:22702195

Molinu, M G; Pani, G; Venditti, T; Dore, A; Ladu, G; D'Hallewin, G



Effect of high pressure processing on the gel properties of salt-soluble meat protein containing CaCl2 and ?-carrageenan.  


The effects of high pressure processing (HPP) on the water-binding capacity and texture profile (TPA) of salt-soluble meat protein (SSMP) containing 0.2% CaCl2 and 0.6% ?-carrageenan (SSMP-CK) gels were investigated. The results showed that 300-400 MPa improved water-binding capacity and decreased TPA parameters of SSMP-CK gels (P<0.05), while 100 MPa could increase hardness and chewiness of the gels. The thermal transition temperature peak for the myosin head (Tpeak1) of SSMP disappeared on addition of CaCl2 and ?-carrageenan. 300 MPa produced a new peak, and caused a shift of the NH-stretching left peak and amide I and the disappearance of NH-stretching right peak. The destruction of network structure and the weakening of molecular interaction within the pressurized gels could result in the decrease of TPA parameters. Thus gelling properties could be modified by HPP, ?-carrageenan and Ca(2+). It is of interest to develop low-fat and sodium-reduced meat products. PMID:23644049

Ma, Fei; Chen, Conggui; Zheng, Lei; Zhou, Cunliu; Cai, Kezhou; Han, Zhuo



Influence of the NaCl or CaCl2 concentration on the structure of heat-set bovine serum albumin gels at pH 7.  


The structure of heat-set systems of the globular protein bovine serum albumin (BSA) was investigated at pH 7 in different salt conditions (NaCl or CaCl(2)) using light scattering. Cross-correlation dynamic light scattering was used to correct for multiple scattering from turbid samples. After heat treatment, aggregates are formed whose size increases as the protein concentration increases. Beyond a critical concentration that decreases with increasing salt concentration, gels are formed. The heterogeneity and the reduced turbidity of the gels were found to increase with increasing salt concentration and to decrease with increasing protein concentration. The structure of the gels is determined by the strength of the repulsive electrostatic interactions between the aggregated proteins. The results obtained in NaCl are similar to those reported in previous studies for other globular proteins. CaCl(2) was found to be much more efficient in reducing electrostatic interactions than NaCl at the same ionic strength. PMID:16004458

Donato, Laurence; Garnier, Catherine; Doublier, Jean-Louis; Nicolai, Taco



Activation of P2Y1 and P2Y2 receptors induces chloride secretion via calcium-activated chloride channels in kidney inner medullary collecting duct cells.  


Dysregulation of urinary sodium chloride (NaCl) excretion can result in extracellular fluid (ECF) volume expansion and hypertension. Recent studies demonstrated that urinary nucleotide excretion increases in mice ingesting a high-salt diet and that these increases in extracellular nucleotides can signal through P2Y(2) receptors in the kidney collecting duct to inhibit epithelial Na(+) channels (ENaC). However, under conditions of ECF volume expansion brought about by high-dietary salt intake, ENaC activity should already be suppressed. We hypothesized that alternative pathways exist by which extracellular nucleotides control renal NaCl excretion. We used an inner medullary collecting duct (mIMCD-K2) cell line in an Ussing chamber system as a model to study additional ion transport pathways that are regulated by extracellular nucleotides. When ENaC was inhibited, the addition of adenosine triphosphate (ATP) to the basal side of cell sheets activated both P2Y(1) and P2Y(2) receptors, inducing a transient increase in short-circuit current (I(sc)); addition of ATP to the apical side activated only P2Y(2) receptors, inducing first a transient and then a sustained increase in I(sc). The ATP-induced increases in I(sc) were blocked by pretreatment with a phospholipase C (PLC) inhibitor, a calcium (Ca(2+)) chelator, or Ca(2+)-activated Cl(-) channel (CACC) inhibitors, suggesting that ATP signals through both PLC and intracellular Ca(2+) to activate CACC. We propose that P2Y(1) and P2Y(2) receptors operate in tandem in IMCD cells to provide an adaptive mechanism for enhancing urinary NaCl excretion in the setting of high-dietary NaCl intake. PMID:21653634

Rajagopal, Madhumitha; Kathpalia, Paru P; Thomas, Sheela V; Pao, Alan C



Activation of P2Y1 and P2Y2 receptors induces chloride secretion via calcium-activated chloride channels in kidney inner medullary collecting duct cells  

PubMed Central

Dysregulation of urinary sodium chloride (NaCl) excretion can result in extracellular fluid (ECF) volume expansion and hypertension. Recent studies demonstrated that urinary nucleotide excretion increases in mice ingesting a high-salt diet and that these increases in extracellular nucleotides can signal through P2Y2 receptors in the kidney collecting duct to inhibit epithelial Na+ channels (ENaC). However, under conditions of ECF volume expansion brought about by high-dietary salt intake, ENaC activity should already be suppressed. We hypothesized that alternative pathways exist by which extracellular nucleotides control renal NaCl excretion. We used an inner medullary collecting duct (mIMCD-K2) cell line in an Ussing chamber system as a model to study additional ion transport pathways that are regulated by extracellular nucleotides. When ENaC was inhibited, the addition of adenosine triphosphate (ATP) to the basal side of cell sheets activated both P2Y1 and P2Y2 receptors, inducing a transient increase in short-circuit current (Isc); addition of ATP to the apical side activated only P2Y2 receptors, inducing first a transient and then a sustained increase in Isc. The ATP-induced increases in Isc were blocked by pretreatment with a phospholipase C (PLC) inhibitor, a calcium (Ca2+) chelator, or Ca2+-activated Cl? channel (CACC) inhibitors, suggesting that ATP signals through both PLC and intracellular Ca2+ to activate CACC. We propose that P2Y1 and P2Y2 receptors operate in tandem in IMCD cells to provide an adaptive mechanism for enhancing urinary NaCl excretion in the setting of high-dietary NaCl intake.

Rajagopal, Madhumitha; Kathpalia, Paru P.; Thomas, Sheela V.



Calcium- and cyclic AMP-dependent chloride secretion in human colonic epithelia.  


Three stable epithelial cell lines (HCA-7, HCA-7-Col 1 and HCA-7-Col 3) all derived from the same human adenocarcinoma have been cultured on collagen-coated Millipore filters. These epithelial monolayers have been used to record short circuit current (SCC) in response to of secretagogues. Similar monolayers, but grown on plastic dishes, were used for measurements of tissue cyclic AMP. Lysylbradykinin, applied to either side of the monolayers, increased SCC in HCA-7 cells but had little effect on the other two lines. The responses showed rapid desensitization, which could be prevented by cooling to 4 degrees C. Responses to kinin were not significantly attenuated by piroxicam, an inhibitor of cyclo-oxygenase. Other secretagogues, vasoactive intestinal polypeptide (VIP) and carbachol also increased SCC in monolayers. The responses to VIP were greatest in HCA-7-Col 1 monolayers while responses were virtually absent in HCA-7-Col 3. A similar profile was seen with carbachol except that responses of HCA-7 and HCA-7-Col 1 monolayers were more equal. With one exception the responses to VIP and carbachol showed sidedness, acting only from the basolateral side. The effects of the secretagogues were inhibited by piretanide, a loop diuretic, applied basolaterally. It is presumed that SCC responses represent electrogenic chloride secretion. Treatment with forskolin increased SCC in HCA-7 and HCA-7-Col 1 monolayers with little effect in HCA-7-Col 3. Nevertheless cyclic AMP levels were elevated most in HCA-7-Col 3 and least in HCA-7-Col 1 monolayers, in reciprocal relationship to the functional response. A23187 increased SCC when applied to HCA-7 and HCA-7-Col 3 monolayers with little effect on HCA-7-Col 1. The differential responses of the three human cell lines provide unique opportunities to discover the functional responsibilities of entities involved in the chloride secretory process. HCA-7-Col 3 cells which generate high levels of cyclic AMP in response to forskolin but which fail to show a substantial chloride secretory response may be a useful model of some disease conditions. PMID:3038239

Cuthbert, A W; Eglme, C; Greenwood, H; Hickman, M E; Kirkland, S C; MacVinish, L J



CaCl(2) as a bifunctional reusable catalyst: diversity-oriented synthesis of 4H-pyran library under ultrasonic irradiation.  


CaCl(2) is applied as an efficient reusable and eco-friendly bifunctional catalyst for the one-pot three-component synthesis of 4H-pyrans under ultrasonic irradiation. A broad range of substrates including the aromatic and heteroaromatic aldehydes, indoline-2,3-dione (isatin) derivatives, acenaphthylene-1,2-dione (acenaphthenequinone) and 2, 2-dihydroxy-2H-indene-1,3-dione (ninhydrin) were condensed with carbonyl compounds possessing a reactive ?-methylene group and alkylmalonates. All reactions are completed in short times, and the products are obtained in good to excellent yields. The catalyst could be recycled and reused several times without any loss of efficiency. PMID:22968516

Safaei, Hamid Reza; Shekouhy, Mohsen; Shirinfeshan, Athar; Rahmanpur, Sudabeh



Influence of partial replacement of NaCl with KCl and CaCl(2) on texture and color of dry fermented sausages.  


A Spanish type of dry fermented sausage, Chorizo de Pamplona, was manufactured with a mixture of (2.29%) different salts (NaCl, KCl, and CaCl(2)) with an equivalent ionic strength to that of the control manufactured with 2.6% NaCl. The use of this salt mixture affected the texture profile analysis (TPA), giving rise to a significant reduction in hardness, cohesiveness, gumminess and chewiness. Instrumental color values showed higher b (yellowness) and L (lightness) values. Sensory texture and color intensity yielded lower scores, but they were classified as acceptable. Principal component analysis was carried out with the instrumental measures. The two principal components explained 76.9% of the variance. Modified and control samples were separated by the first component, which explained 57.1% of the variance and was defined basically by texture parameters. PMID:10552384

Gimeno, O; Astiasarn, I; Bello, J



Effects of magnesium chloride and organic additives on the synthesis of aragonite precipitated calcium carbonate  

NASA Astrophysics Data System (ADS)

The synthesis of aragonite precipitated calcium carbonate by treating a suspension of Ca(OH) 2 with CO 2 gas was investigated with regard to the effects of Mg 2+ ions and organic additives on polymorphism and alternative orientations. In the presence of a small amount of Mg 2+, Mg-calcite formed, but as the Mg 2+ ion concentration increased, the amount of Mg-calcite decreased and the amount of aragonite increased. Thus, the formation of Mg-calcite is suppressed and only aragonite is formed in the presence of 60 mol% MgCl 2. As the Mg 2+ ion concentration increased, the aragonite that formed was found to have decreased in terms of its longitude and aspect ratio. Furthermore, the effect of Mg 2+ ions in conjunction with organic additives was also investigated with regard to polymorphs and morphology and the structure-forming properties of the organic additives.

Park, Woon Kyoung; Ko, Sang-Jin; Lee, Seung Woo; Cho, Kye-Hong; Ahn, Ji-Whan; Han, Choon



Exposure to Cigarette Smoke Condensate Reduces Calcium Activated Chloride Channel Transport in Primary Sinonasal Epithelial Cultures  

PubMed Central

Background The cystic fibrosis transmembrane conductance regulator (CFTR) serves as a predominant Cl? transport conduit in airway epithelium and is inhibited by cigarette smoke in vitro and in vivo. Activation of secondary Cl? transport pathways through calcium-activated Cl? channels (CaCC) has been postulated as a mechanism to bypass defects in CFTR-mediated transport. Because it is not known whether CaCCs are also inhibited by tobacco exposure, the current study was designed to investigate the effect of cigarette smoke condensate (CSC) on CaCC transport. Study Design In vitro study Methods Well-characterized primary murine nasal septal epithelial (MNSE) and human sinonasal epithelial (HSNE) cultures were exposed to CSC in Ussing chambers. We monitored CaCC short-circuit current through stimulation of P2Y purinergic receptors with UTP or ATP and selective inhibition of the CFTR dependent secretory pathway. Characterization of CaCC current was also accomplished in primary airway cells derived from transgenic CFTR?/? (knockout) murine models. Results Change in CaCC-mediated current (?ISC - representing transepithelial Ca-mediated Cl? secretion in A/cm2) was significantly decreased in CSC-exposed wild type MNSE when compared to controls{(32.8 +/? 4.6 vs. 47.5 +/? 2.3; respectively) p < 0.02}. A similar effect was demonstrated in CFTR?/? MNSE cultures(33.4 +/? 2.8 vs. 38.6 +/? 2.0; p<0.05}. HSNE cultures also had a significant reduction in ISC (16.1 +/? 0.6 vs. 22.7 +/? 0; p=0.008). Conclusions CSC affects multiple pathways fundamental to airway ion transport, including both cAMP and calcium activated Cl? transport. Inhibition of Cl? transport may contribute to common diseases of the airways, such as chronic rhinosinusitis and chronic obstructive pulmonary disease.

Virgin, Frank W.; Azbell, Christopher; Schuster, Daniel; Sunde, Jumin; Zhang, Shaoyan; Sorscher, Eric J.; Woodworth, Bradford A.



The simultaneous removal of calcium, magnesium and chloride ions from industrial wastewater using magnesium-aluminum oxide.  


In this article, a method for simultaneous removal of calcium, magnesium and chloride by using Mg0.80Al0.20O1.10 as a Magnesium-Aluminum oxide (Mg?Al oxide) was investigated. Mg?Al oxide obtained by thermal decomposition of the Mg-Al layered double hydroxide (Mg-Al LDH). The synthesized Mg?Al oxide were characterized with respect to nitrogen physicosorption, X-ray diffraction (XRD) and field emission scan electron microscopy (FESEM) morphology. Due to high anion-exchange capacity of Mg?Al oxide, it was employed in simultaneously removal of Cl(-), Mg(+2) and Ca(+2) from distiller waste of a sodium carbonate production factory. For this purpose, experiments were designed to evaluate the effects of quantity of Mg?Al oxide, temperature and time on the removal process. The removal of Cl(-), Mg(+2) and Ca(+2) from wastewater was found 93.9%, 93.74% and 93.25% at 60C after 0.5h, respectively. Results showed that the removal of Cl(-), Mg(+2) and Ca(+2) by Mg?Al oxide increased with increasing temperature, time and Mg?Al oxide quantity. PMID:23647113

Hamidi, Roya; Kahforoushan, Davood; Fatehifar, Esmaeil



Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure  

SciTech Connect

The extent of reaction of alloy-22 with limited amounts of aqueous calcium chloride (CaCl{sub 2}) was investigated. Alloy-22 is a highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloy. Specimens were polished to a mirror finish prior to aerosol salt deposition. An aqueous film was formed by deliquescence of deposited CaCl{sub 2} at 150 C and 22.5% relative humidity (RH). The reactant gas was a continuous flow of purified humidified laboratory air. The reaction progress as a function of time was continuously measured in-situ by a micro-balance. An initial weight gain due to deliquescence of the CaCl{sub 2} was observed. A steady weight loss was observed over the next 72 hours, after which no further weight change was observed. During this weight loss, white precipitates formed and the specimen's surface became visibly dry. The precipitate crystals were identified as Ca(OH){sub 2} by post-test Raman spectroscopy; however, energy dispersive X-ray spectroscopy indicated that there was a significant amount of chlorine contained in them.

Hailey, P; Gdoowski, G



Relationship between Calcium-Activated Chloride Channel 1 and MUC5AC in Goblet Cell Hyperplasia Induced by Interleukin13 in Human Bronchial Epithelial Cells  

Microsoft Academic Search

Background:Interleukin (IL)-13 has recently been reported as the major T-helper 2 cytokine involved in mucus overproduction and oversecretion in allergic airways. However, the relationship between human calcium-activated chloride channel-1 (hCLCA1) and MUC5AC induced by IL-13 in vitro has not been fully investigated. Objectives: The present study examines whether IL-13 induces the expression of hCLCA1 in normal human bronchial epithelial (NHBE)

Masanori Yasuo; Keisaku Fujimoto; Tsuyoshi Tanabe; Hironobu Yaegashi; Kenji Tsushima; Keiichirou Takasuna; Takeshi Koike; Mutsuo Yamaya; Toshio Nikaido



Calcium Chloride Concentration, Injection Time, and Aging Period Effects on Tenderness, Sensory, and Retail Color Attributes of Loin Steaks from Mature Cows1  

Microsoft Academic Search

Calcium chloride (CaC12) injection effects on retail color changes and sensory traits of loin steaks from mature cows were studied. Left side strip loins (SL) of 10 carcasses were divided into three portions within .5 h postmortem. One was a control, and the other portions were injected with either 150 mM or 200 mM CaC12. At 24 h postmortem, the

J. J. B. Diles; M. F. Milles; B. L. Owen



Synergetic effect of poly(vinyl butyral) and calcium carbonate on thermal stability of poly(vinyl chloride) nanocomposites investigated by TGFTIRMS  

Microsoft Academic Search

In order to improve poly(vinyl chloride) (PVC) thermal stability, poly(vinyl butyral) (PVB) matrix and calcium carbonate nanoparticles\\u000a were incorporated in plasticized PVC. Thermal properties of these composites were investigated by thermogravimetry analysis\\u000a coupled with mass spectrometry and Fourier transform infrared spectroscopy (FTIR). This approach highlighted the efficiency\\u000a of both PVB and CaCO3 as HCl scavengers by postponing both the onset

Stphanie Etienne; Claude Becker; David Ruch; Albert Germain; Cdric Calberg



Calcium dependent action potentials produced in leech Retzius cells by tetraethylammonium chloride.  

PubMed Central

1. Retzius cells of leech segmental ganglia were exposed to tetraethylammonium chloride (TEA) presented both extracellularly, dissolved in the perfusing fluid, and intracellulary, by iontophoresis from a microelectrode. 2. Extracellular TEA, 10 and 25 mM, greatly prolonged the cells' action potentials, and the higher concentration increased their amplitude as well. At 10 mM the characteristic changes developed gradually over a period of about half an hour, while at 25 mM they appeared much more rapidly. However, at both concentrations the changes were reversible within minutes, even after long soaks in drug-containing solution. It is therefore probable that the drug acted at the outer surface of the membrane. 3. Intracellular TEA also prolonged the action potentials but there were several differences from the response produced by extracellular application. The changes developed gradually, and for a time, each firing of the cell was a complex event consisting of several early, brief depolarizations followed by a single much larger and more prolonged one. The large, late depolarization eventually obliterated the early ones; its gradual development suggested that it was produced only after TEA diffused to some extrasomatic portion of the cell. Intracellular TEA always caused progressive depolarization; this and the changes in the action potential were both irreversible, suggesting that the site of action was on the inner surface of the membrane. 4. Manipulations of external Na and Ca provided evidence that (a) in the absence of TEA, Retzius cell action potentials were exclusively Na-dependent, (b) that the early depolarizations in the complex action potentials produced by intracellular TEA were Na-dependent, while the later, large depolarization was Ca-dependent and (c) that the prolonged action potentials produced by extracellular TEA contained a large Ca-dependent component. 5. We conclude that TEA, acting from either side of the membrane, caused a voltage-sensitive, slowly activated Ca current to become a major contributor to the inward current of the action potential, probably by blocking the outward K current which ordinarily counteracts it. However, we cannot rule out the possibility that TEA enabled a Ca current by some means independent of its presumed action on K conductance. 6. Data resembling ours in some respects have been obtained from studies of the action of TEA on frog dorsal root ganglion cells, frog neuromuscular junction, and squid stellate ganglion. No clear counterpart of our findings has been reported form experiments on squid and amphibian axons, molluscan neurones, or frog skeletal muscle fibres.

Kleinhaus, A L; Prichard, J W



Dissecting a regulatory calcium-binding site of CLC-K kidney chloride channels  

PubMed Central

The kidney and inner ear CLC-K chloride channels, which are involved in salt absorption and endolymph production, are regulated by extracellular Ca2+ in the millimolar concentration range. Recently, Gradogna et al. (2010. J. Gen. Physiol. identified a pair of acidic residues (E261 and D278) located in the loop between helices I and J as forming a putative intersubunit Ca2+-binding site in hClC-Ka. In this study, we sought to explore the properties of the binding site in more detail. First, we verified that the site is conserved in hClC-Kb and rClC-K1. In addition, we could confer Ca2+ sensitivity to the Torpedo marmorata ClC-0 channel by exchanging its IJ loop with that from ClC-Ka, demonstrating a direct role of the loop in Ca2+ binding. Based on a structure of a bacterial CLC and a new sequence alignment, we built homology models of ClC-Ka. The models suggested additional amino acids involved in Ca2+ binding. Testing mutants of these residues, we could restrict the range of plausible models and positively identify two more residues (E259 and E281) involved in Ca2+ coordination. To investigate cation specificity, we applied extracellular Zn2+, Mg2+, Ba2+, Sr2+, and Mn2+. Zn2+ blocks ClC-Ka as well as its Ca2+-insensitive mutant, suggesting that Zn2+ binds to a different site. Mg2+ does not activate CLC-Ks, but the channels are activated by Ba2+, Sr2+, and Mn2+ with a rank order of potency of Ca2+ > Ba2+ > Sr2+ = Mn2+ for the human CLC-Ks. Doseresponse analysis indicates that the less potent Ba2+ has a lower affinity rather than a lower efficacy. Interestingly, rClC-K1 shows an altered rank order (Ca2+ > Sr2+ >> Ba2+), but homology models suggest that residues outside the IJ loop are responsible for this difference. Our detailed characterization of the regulatory Ca2+-binding site provides a solid basis for the understanding of the physiological modulation of CLC-K channel function in the kidney and inner ear.

Gradogna, Antonella; Fenollar-Ferrer, Cristina



Calcium-activated chloride channels in bovine pulmonary artery endothelial cells.  

PubMed Central

1. We characterized Ca(2+)-activated Cl- currents in calf pulmonary artery endothelial (CPAE) cells by using a combined patch clamp and fura-2 microfluorescence technique to simultaneously measure ionic currents and the intracellular Ca2+ concentration, [Ca2+]i. 2. Various procedures that increased [Ca2+]i, such as stimulation with ATP or ionomycin, or loading the cells with Ca2+ via the patch pipette, activated a strongly outwardly rectifying current with a reversal potential close to the Cl- equilibrium potential. Changing the extracellular Cl- concentration shifted this reversal potential as predicted for a Cl- current. Buffering Ca2+ rises with BAPTA prevented ATP from activating the current. 3. Ca(2+)-activated Cl- currents could be distinguished from volume-activated Cl- currents, which were sometimes coactivated in the same cell. The latter showed much less outward rectification, their activation was voltage independent, and they could be inhibited by exposing the cells to hypertonic solutions. 4. The permeability ratio for the Ca(2+)-activated conductance of the anions iodide:chloride: gluconate was 1.71 +/- 0.06:1:0.39 +/- 0.03 (n = 12). 5. This Ca(2+)-activated Cl- current, ICl, Ca, inactivated rapidly at negative potentials and activated slowly at positive potentials. Outward tail currents were slowly decaying, while inward tail currents decayed much faster. 6. 4,4'-Diisothiocyanatostilbene-2,2'-disulphonic-acid (DIDS) and niflumic acid inhibited Icl,Ca in a voltage-dependent manner, i.e. they exerted a more potent block at positive potentials. The block by N-phenylanthracilic acid (NPA), 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) and tamoxifen was voltage independent. Niflumic acid and tamoxifen were the most potent blockers. 7. The single-channel conductance was 7.9 +/- 0.7 pS (n = 15) at 300 mM extracellular Cl-. The channel open probability was high at positive potentials, but very small at negative potentials. 8. It is concluded that [Ca2+]i activates small-conductance Cl- channels in endothelial cells, which coexist with the volume-activated Cl- channels described previously. Images Figure 5 Figure 7

Nilius, B; Prenen, J; Szucs, G; Wei, L; Tanzi, F; Voets, T; Droogmans, G



Experimental determination of REE fractionation between liquid and vapour in the systems NaCl-H 2 O and CaCl 2 -H 2 O up to 450 C  

Microsoft Academic Search

Fractionation of selected REE between brine and vapour was experimentally determined using a large-volume rocking Ti-autoclave that allowed quasi-isobaric sampling of liquid-vapour pairs. Samples were extracted along the 350, 400 and 450 C-isotherms of the H2O-NaCl system, and along the 400 C isotherm of the CaCl2 system. Total salt concentrations were either 6.6 and 10 wt% NaCl or CaCl2, respectively,

Kirill Shmulovich; Wilhelm Heinrich; Peter Mller; Peter Dulski



Energetics of calcium efflux from cells of Escherichia coli.  

PubMed Central

Intact cells of a H+-translocating ATPase-deficient strain of Escherichia coli were starved of endogenous energy reserves and passively loaded with 45CaCl2. Energy-dependent efflux of calcium was observed upon addition of glucose or respiratory substrates. Addition of cyanide or uncouplers prevented efflux. It is concluded that calcium efflux in intact cells is coupled to the proton motive force via secondary calcium-proton exchange.

Tsujibo, H; Rosen, B P



Effects of lanthanum chloride on glutamate level, intracellular calcium concentration and caspases expression in the rat hippocampus.  


Lanthanum chloride (LaCl(3)) can affect neurobehavioral development and impair cognitive abilities. The mechanism underlying LaCl(3)-induced neurotoxic effects is still unknown. The purpose of this research was to investigate the neuronal impairment induced by LaCl(3) and discuss the possible mechanism from the aspects of the alteration of glutamate level, intracellular calcium concentration ([Ca(2+)](i)), Bax, Bcl-2 and caspases expression in the hippocampus. Lactational rats were exposed to 0, 0.25, 0.50 and 1.0% LaCl(3) in drinking water, respectively. Their offspring were exposed to LaCl(3) by parental lactation and then administrated with 0, 0.25, 0.50 and 1.0% LaCl(3) in drinking water for 1month. The results showed that 0.25, 0.50 and 1.0% LaCl(3) exposure induced neuronal impairment in the hippocampus of young rat. Hippocampal glutamate level, [Ca(2+)](i) and ratio of Bax and Bcl-2 expression increased significantly after LaCl(3) exposure. Besides, LaCl(3) exposure increased GRP78, GRP94, GADD153 and p-JNK expression, promoted the activation of caspase-3, caspase-9 and caspase-12, induced PARP cleavage and caused excessive apoptosis. These results indicate that LaCl(3) increases glutamate level, [Ca(2+)](i) and ratio of Bax and Bcl-2 expression, which cause excessive apoptosis by the mitochondrial and endoplasmic reticulum stress-induced pathway, and thus neuronal damages in the hippocampus. PMID:23097080

Yang, Jinghua; Liu, Qiufang; Wu, Shengwen; Xi, Qi; Cai, Yuan



Direct electrochemical reduction of solid vanadium oxide to metal vanadium at low temperature in molten CaCl2-NaCl  

NASA Astrophysics Data System (ADS)

V2O5 sintered pellets and graphite rods were employed as the cathode and the anode, respectively; a molten CaCl2-NaCl salt was used as the electrolyte. Then, V2O5 was directly reduced to metal vanadium by the Fray-Farthing-Chen (FFC) method at 873 K to realize low-temperature electrolysis. Two typical experimental conditions, electrolysis time and voltage, were taken into account to investigate the current efficiency and remaining oxygen content in electrolyzed products. The composition and microstructure of the products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM observations show that a higher voltage (1.8-3.4 V) and a longer electrolysis time (2-5 h) can improve the product quality separately, that is, a lower remaining oxygen content and a more uniform microstructure. The products with an oxygen content of 0.205wt% are successfully obtained below 3.4 V for 10 h. However, the current efficiency is low, and further work is required.

Cai, Zhuo-fei; Zhang, Zhi-mei; Guo, Zhan-cheng; Tang, Hui-qing



Adsorption of iron oxide nanoclusters stabilized with sulfonated copolymers on silica in concentrated NaCl and CaCl2 brine.  


Transport of metal oxide nanoparticles in porous rock is of interest for imaging and oil recovery in subsurface reservoirs, which often contain concentrated brine. Various copolymers composed of acrylic acid and either 2-acrylamido-2-methylpropanesulfonate or styrenesulfonate were synthesized and adsorbed on iron oxide nanoclusters to provide colloidal stability and to achieve low adsorption on silica in high salinity brine composed of 8%wt. NaCl+2%wt. CaCl2. Furthermore, the degree of adsorption of the nanoparticles on silica was controlled by modifying the acrylic acid groups in the copolymers with a series of diamines and triamines to add hydrophobicity. The adsorption on colloidal silica microparticles ranged from <1 mg/m(2) for highly charged hydrophilic surfaces on the iron oxide nanoparticles to 22 mg/m(2) for the most hydrophobic amine-modified surfaces, corresponding to monolayer coverages that ranged from 0.2% to 11.5%, respectively. The specific adsorption (mg-IO/m(2)-silica), monolayer coverage, and parameters for Langmuir isotherms were evaluated for various IO nanoclusters as a function of the properties of the copolymers on their surfaces. PMID:23473572

Bagaria, Hitesh G; Neilson, Bethany M; Worthen, Andrew J; Xue, Zheng; Yoon, Ki Youl; Cheng, Victoria; Lee, Jae Ho; Velagala, Sindhuja; Huh, Chun; Bryant, Steven L; Bielawski, Christopher W; Johnston, Keith P



Direct interactions between Z-DNA and alkaline earth cations, discovered in the presence of high concentrations of MgCl2 and CaCl2.  


In this study, crystals of Z-DNA hexamer d(CGCGCG) complexed with MgCl2 and CaCl2 were obtained in the presence of high concentrations of alkaline earth salts (500mM) using a temperature control technique, and their crystal structures were determined at 1.3 resolution. Mg(2+) and Ca(2+) cations in these structures tend to interact directly with phosphate groups of Z-DNA duplexes; however, they tend to form water-mediated interactions with Z-DNA in the presence of lower concentrations of alkaline earth salts. In these crystals, a DNA duplex was laid along its c-axis and interacted with its 6 neighboring DNA duplexes through coordination bonds of PO(Mg(2+) or Ca(2+))OP. A symmetrical hexagonal Z-DNA duplex assembly model may explain DNA condensation caused by alkaline earth salts. These structures offer insights into the functions of alkaline earth cations essential to the structures and assembly of Z-DNA duplexes. PMID:23578858

Chatake, Toshiyuki; Sunami, Tomoko



Combined effects of 1-methylcyclopropene, calcium chloride dip, and\\/or atmospheric modification on quality changes in fresh-cut strawberries  

Microsoft Academic Search

The aim of this study was to determine the effects of 1-methylcyclopropene, 1-MCP (1?LL?1 for 24h at 5C) on quality attributes and shelf life of fresh-cut strawberries. The 1-MCP was applied before (whole product) and\\/or after cutting (wedges), followed by storage in a continuous flow of air or air +1?LL?1 C2H4. The combined effects of 1-MCP and CaCl2 dips (1%

E. Aguayo; R. Jansasithorn; A. A. Kader



CFTR and calcium-activated chloride channels in primary cultures of human airway gland cells of serous or mucous phenotype.  


Using cell culture models, we have investigated the relative importance of cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride channels (CaCC) in Cl secretion by mucous and serous cells of human airway glands. In transepithelial recordings in Ussing chambers, the CFTR inhibitor CFTR(inh)-172 abolished 60% of baseline Cl secretion in serous cells and 70% in mucous. Flufenamic acid (FFA), an inhibitor of CaCC, reduced baseline Cl secretion by ?20% in both cell types. Methacholine and ATP stimulated Cl secretion in both cell types, which was largely blocked by treatment with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) and partially by mucosal FFA or CFTR(inh)-172 with the exception of methacholine responses in mucous cells, which were not blocked by FFA and partially (?60%) by CFTR(inh)-172. The effects of ionomycin on short-circuit current (I(sc)) were less than those of ATP or methacholine. Forskolin stimulated Cl secretion only if Cl in the mucosal medium was replaced by gluconate. In whole cell patch-clamp studies of single isolated cells, cAMP-induced Cl currents were ?3-fold greater in serous than mucous cells. Ionomycin-induced Cl currents were 13 times (serous) or 26 times (mucous) greater than those generated by cAMP and were blocked by FFA. In serous cells, mRNA for transmembrane protein 16A (TMEM16A) was ?10 times more abundant than mRNA for CFTR. In mucous cells it was ?100 times more abundant. We conclude: 1) serous and mucous cells both make significant contributions to gland fluid secretion; 2) baseline Cl secretion in both cell types is mediated predominantly by CFTR, but CaCC becomes increasingly important after mediator-induced elevations of intracellular Ca; and 3) the high CaCC currents seen in patch-clamp studies and the high TMEM16A expression in intact polarized cells sheets are not reflected in transepithelial current recordings. PMID:20675434

Fischer, Horst; Illek, Beate; Sachs, Lorne; Finkbeiner, Walter E; Widdicombe, Jonathan H



Effects of chloride, calcium, and dissolved organic carbon on silver toxicity: Comparison between rainbow tout and fathead minnows  

SciTech Connect

The effects of independently altering chloride, calcium, and dissolved organic carbon (DOC) on the toxicity of silver were compared between rainbow trout (Oncorhynchus mykiss) and fathead minnows (Pimephales promelas). The 96-h median lethal concentration toxicity tests for both species were performed under the same conditions, within the same containers. In addition, the effect of altering [Cl{sup {minus}}] on silver-induced perturbations to body Na{sup +} influx and gill silver load was studied. Toxicity tests were conducted in synthetic soft water (50 {micro}M Na{sup +}, 50 {micro}M Cl{sup {minus}}, 50 {micro}M Ca{sup 2+}, 0.3 mg DOC/L). The [Cl{sup {minus}}], [Ca{sup 2+}], and [DOC] were adjusted by the addition of NaCl, CaNO{sub 3}, or humic acid, respectively. On the basis of total silver, increasing [Cl{sup {minus}}] over a range of 50 {micro}M to 1,500 {micro}M resulted in a 4.3-fold increase in the 96-h LC50 values (decrease in toxicity) for rainbow trout, but did not significantly affect the 96-h LC50 values for fathead minnows. Increasing water [Ca{sup 2+}] (from 50 to 2,000 {micro}M) had only a small influence on the 96-h LC50 values in both species. If the 96-h LC50 values are calculated on the basis of ionic silver, Ag{sup +}, then, in the case of rainbow trout, toxicity correlates to Ag{sup +}. However, this correlation does not exist for fathead minnows. Increasing [Cl{sup {minus}}] did not affect the degree of perturbation of Na{sup +} influx during acute exposure (first 4 h) to 8 {micro}g Ag/L in either species, nor did it affect the whole-body silver uptake rates, but it did reduce the gill silver load. These results demonstrate that differences exist in the way in which water chemistry ameliorates silver toxicity between rainbow trout and fathead minnows.

Bury, N.R. [INRA, Rennes (France). Lab. de Physiologie des Poissons; Galvez, F.; Wood, C.M. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Biology



On the preparation of TiAl alloy by direct reduction of the oxide mixtures in calcium chloride melt  

SciTech Connect

In recent years, TiAl-based intermetallic alloys are being increasingly considered for application in areas such as (i) automobile/transport sector (passenger cars, trucks and ships) (ii) aerospace industry (jet engines and High Speed Civil Transport propulsion system) and (iii) industrial gas turbines. These materials offer excellent (i) high temperature properties (at higher than 6000C) (ii) mechanical strength and (iii) resistance to corrosion and as a result have raised renewed interest. The combination of these properties make them possible replacement materials for traditional nickel-based super-alloys, which are nearly as twice as dense (than TiAl based alloys). Since the microstructures of these intermetallic alloys affect, to a significant extent, their ultimate performance, further improvements (by way of alteration/modification of these microstructures), have been the subject matter of intense research investigations. It has now been established that the presence of alloy additives, such as niobium, tantalum, manganese, boron, chromium, silicon, nickel and yttrium etc, in specific quantities, impart marked improvement to the properties, viz. fatigue strength, fracture toughness, oxidation resistance and room temperature ductility, of these alloys. From a number of possible alloy compositions, {gamma}-TiAl and Ti-Al-Nb-Cr have, of late, emerged as two promising engineering alloys/materials. . The conventional fabrication process of these alloys include steps such as melting, forging and heat treatment/annealing of the alloy compositions. However, an electrochemical process offers an attractive proposition to prepare these alloys, directly from the mixture of the respective oxides, in just one step. The experimental approach, in this new process, was, therefore, to try to electrochemically reduce the (mixed) oxide pellet to an alloy phase. The removal of oxygen, from the (mixed) oxide pellet, was effected by polarizing the oxide pellet against a graphite electrode in a pool of molten calcium chloride at a temperature of 9000C. The dominant mechanism of the oxygen removal was the ionization of oxygen followed by its subsequent discharge, as CO2/CO, at the anode surface. The removal of oxygen from the oxide mixture helped form the alloy in situ. The presentation shall cover the detailed experimental results pertaining to the preparation, evaluation and characterization of Ti-47Al-2Nb-2Cr (atom%) alloy.

Prabhat K. Tripathy; Derek J. Fray



Effects of Calcium Chloride on Growth, Membrane Permeability and Root Hydraulic Conductivity in Two Atriplex Species Grown at High (Sodium Chloride) Salinity  

Microsoft Academic Search

Calcium (Ca) has an important role in plant physiology, including involvement in the responses to salt stress, and controls numerous processes. To overcome the negative impact of high salinity, the addition of supplemental Ca to the growth medium as an ameliorative agent could be necessary. Atriplex halimus subsp. schweinfurthii and Atriplex canescens subsp. linearis were grown in hydroponic conditions to

Bouzid Nedjimi; Youcef Daoud



Calcium-mediated responses and glutamine synthetase expression in greater duckweed (Spirodela polyrhiza L.) under diethyl phthalate-induced stress.  


This study was carried out to assess the influence of diethyl phthalate (DEP) alone or associated with calcium chloride (CaCl2) on greater duckweed plants, emphasizing the implications of calcium in amelioration of DEP-induced stress on plant growth. Greater duckweed were treated with DEP in variable concentrations, as 0, 0.25, 0.5, 1.0 and 2.0mM for 7 days, or treated with the same concentration either 2mM DEP or 2mM DEP plus 10mM CaCl22H2O in different duration 0-7 days. Treatment with 2mM DEP resulted in increasing proline content, protease activity, and ammonia accumulation in duckweed tissues. NADH-glutamate dehydrogenase (NADH-GDH; EC and ?(1)-pyrroline-5-carboxylate reductase (P5CR; EC, two key enzymes in the glutamate pathway of proline synthesis, showed increase in activity with DEP treatment and positively correlated with proline accumulation. No further increase in proline accumulation was observed with addition of calcium chloride to the DEP-treated cultures. However, supplementation of Ca(2+) can mitigate the adverse effect of DEP, at least in part to decrease the DEP-induced superoxide accumulation and increase in GDH activity for ammonia assimilation in duckweed fronds. In addition, effects of calcium on mitigation of DEP injury were also observed in glutamine synthetase (GS; EC expression. Both GS1 and GS2 polypeptide accumulation and the level of total GS activity were nearly equivalent to the control. Exogenous proline protects GS2 from DEP-modulated redox damage in the chloroplast lysates but there is no remarkable protection effects on D1 (the 32kDa protein in photosystem II reaction center) degradation. In conclusion, the glutamate pathway of proline synthesis might be involved in mitigation of DEP-induced injury, and calcium plays an important role in increasing GDH, P5CR, and GS expression. PMID:24177215

Cheng, Lee-Ju; Hung, Meng-Ju; Cheng, Yen-I; Cheng, Tai-Sheng



Three-day-old human unfertilized oocytes after in vitro fertilization/intracytoplasmic sperm injection can be activated by calcium ionophore a23187 or strontium chloride and develop to blastocysts.  


Abstract Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3-5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p<0.05); there was significant difference between two groups (p<0.05). Among the 44 cleaved oocytes in the calcium ionophore A23187 group, eight developed to the two- to four-cell stage, 17 developed to the five- to eight-cell stage, 15 developed to greater than the eight-cell stage, and four blastocysts were obtained. Among the 21 cleaved oocytes in the strontium chloride group, six developed to the two- to four- cell stage, 10 developed to the five- to eight-cell stage, four developed to greater than the eight-cell stage, and one blastocyst was obtained. Three-day-old unfertilized human oocytes after IVF or ICSI could be activated by the calcium ionophore A23187 or strontium chloride, and a small part of parthenogenetic embryos developed into blastocysts. The treatment with the calcium ionophore A23187 was better than that of strontium chloride in respect to the activation rate of 3-day-old unfertilized human oocytes after IVF or ICSI. PMID:24960285

Liu, Ying; Han, Xiao-Jie; Liu, Ming-Hui; Wang, Shu-Yu; Jia, Chan-Wei; Yu, Lan; Ren, Guoqing; Wang, Li; Li, Wei



Developmental expression of the calcium-activated chloride channels TMEM16A and TMEM16B in the mouse olfactory epithelium.  


Calcium-activated chloride channels are involved in several physiological processes including olfactory perception. TMEM16A and TMEM16B, members of the transmembrane protein 16 family (TMEM16), are responsible for calcium-activated chloride currents in several cells. Both are present in the olfactory epithelium of adult mice, but little is known about their expression during embryonic development. Using immunohistochemistry we studied their expression in the mouse olfactory epithelium at various stages of prenatal development from embryonic day (E) 12.5 to E18.5 as well as in postnatal mice. At E12.5, TMEM16A immunoreactivity was present at the apical surface of the entire olfactory epithelium, but from E16.5 became restricted to a region near the transition zone with the respiratory epithelium, where localized at the apical part of supporting cells and in their microvilli. In contrast, TMEM16B immunoreactivity was present at E14.5 at the apical surface of the entire olfactory epithelium, increased in subsequent days, and localized to the cilia of mature olfactory sensory neurons. These data suggest different functional roles for TMEM16A and TMEM16B in the developing as well as in the postnatal olfactory epithelium. The presence of TMEM16A at the apical part and in microvilli of supporting cells is consistent with a role in the regulation of the chloride ionic composition of the mucus covering the apical surface of the olfactory epithelium, whereas the localization of TMEM16B to the cilia of mature olfactory sensory neurons is consistent with a role in olfactory signal transduction. 2013 Wiley Periodicals, Inc. Develop Neurobiol 74: 657-675, 2014. PMID:24318978

Maurya, Devendra Kumar; Menini, Anna



Solubilization of rare earth oxides in the eutectic LiClKCl mixture at 450 C and in the equimolar CaCl 2NaCl melt at 550 C  

Microsoft Academic Search

Solubilization studies of rare earth oxides and oxohalides have been carried out in the eutectic LiClKCl melt at 450C and the equimolar CaCl2NaCl mixture at 550C. First, chlorinating conditions were predicted by comparing the EpO2? diagram of the different rare earth-O compounds to that of several chlorinating gaseous mixtures. Then, experimental solubilization tests were performed by using pure HCl and

Y. Castrillejo; M. R. Bermejo; E. Barrado; A. M. Mart??nez; P. D??az Arocas



Influence of storage time and temperature of air-dried soils on pH and extractable nutrients using 0.01 mol\\/L CaCl2  

Microsoft Academic Search

The stability of pH and certified amounts of nitrate, ammonia, total soluble nitrogen, total soluble organic carbon, magnesium,\\u000a sodium, potassium and phosphorus obtained by extraction from air-dried (40 C) soil samples by 0.01 mol\\/L CaCl2 solution during storage at 18 C, 4 C, ambient temperature, 40 C and 70 C was investigated in one calcareous soil and\\u000a one acid sandy

V. J. G. Houba; I. Novozamsky



Calcium alginate microcapsule generation on a microfluidic system fabricated using the optical disk process  

NASA Astrophysics Data System (ADS)

This paper describes the generation of monodisperse calcium alginate (Ca-alginate) microcapsules on a microfluidic platform using the commercial optical disk process. Our strategy is based on combining the rapid injection molding process for a cross-junction microchannel with the sheath focusing effect to form uniform water-in-oil (w/o) emulsions. These emulsions, consisting of 1.5% (w/v) sodium alginate (Na-alginate), are then dripped into a solution containing 20% (w/v) calcium chloride (CaCl2) creating Ca-alginate microparticles in an efficient manner. This paper demonstrates that the size of Ca-alginate microparticles can be controlled from 20 m to 50 m in diameter with a variation of less than 10%, simply by altering the relative sheath/sample flow rate ratio. Experimental data show that for a given fixed dispersed phase flow (sample flow), the emulsion size decreases as the average flow rate of the continuous phase flow (sheath flow) increases. The proposed microfluidic platform is capable of generating relatively uniform emulsions and has the advantages of active control of the emulsion diameter, a simple and low cost process and a high throughput.

Huang, Keng-Shiang; Liu, Ming-Kai; Wu, Chun-Han; Yen, Yu-Tang; Lin, Yu-Cheng



Effect of ammonium chloride and dietary phosphorus in the azotaemic rat. Part II-kidney hypertrophy and calcium deposition  

Microsoft Academic Search

Background. Kidney hypertrophy is stimulated by both partial nephrectomy and NH4Cl administration. Also, parathyroidectomy (PTX) has been reported to prevent kidney hypertrophy induced by a high protein diet. Our goal was to determine in the azotaemic rat: (i) the combined effects of NH4Cl administration and dietary phosphorus on the development of kidney hypertrophy and calcium deposition in the kidney and

Aquiles Jara; Cecilia Chacon; Magdalena Ibaceta; Andres Valdivieso; Arnold J. Felsenfeld


Effect of curing temperature on corrosion of steel bars embedded in calcium aluminate mortars exposed to chloride solutions  

Microsoft Academic Search

Important corrosion problems have been detected in reinforced concretes made of calcium aluminate cement (CAC). However, very little research has been performed to evaluate the incidence of the use of such cement on the corrosion process. Reinforced mortar specimens, pre-mixed with or without 4% NaCl of weight of cement, cured at 20 C, 40 C and 60 C for two

M. a Sanjun



Preparation of Titanium Powders from TiO2 by Calcium Vapor Reduction  

NASA Astrophysics Data System (ADS)

Preparation of Ti powders from TiO2 by calcium vapor reduction was investigated by x-ray diffraction (XRD), scanning electron microscope (SEM), element analysis instrument, inert gas fusion-infrared absorption spectroscopy, and ethylene diamine tetraacetic acid (EDTA) complex formation titration. The experimental results indicate that the reduction reaction occurs very rapidly when the mass ratio of CaCl2 to TiO2 is 1:2 from 0 min to 30 min, and the titanium suboxides were further reduced from 30 min to 480 min at 1000C. The content of CaCl2 influences the reduction products and the reduction rate obviously, and the suitable mass ratio of CaCl2 to TiO2 is 1:2 under these experimental conditions. Ti powders with oxygen content of 1000 ppm, nitrogen content of 120 ppm, and chlorine content of 80 ppm were obtained at 1000C for 360 min.

Jia, Jingang; Xu, Baoqiang; Yang, Bin; Wang, Dongsheng; Liu, Dachun



A robust pH-sensitive drug carrier: Aqueous micelles mineralized by calcium phosphate based on chitosan.  


This study developed an exciting alternative to the polymeric delivery system in cancer therapy. In this study, novel organic-inorganic hybrid polymeric micelles based on chitosan were synthesized and found to be robust nanocarriers for intracellular controlled release drug delivery. The polymeric micelles of carboxymethyl chitosan-grafted-p(ethylene glycol)-dodecylamine (CMC-g-PEG-DDA) were readily mineralized in the presence of calcium chloride (CaCl2) and disodium hydrogen phosphate (Na2HPO4). Mineralization reduced polymeric micelles' size from 239nm to 138nm and formed a multi-core structure. The mineralized polymeric micelles (MPM) exhibited enhanced serum stability. The DOX release from the DOX-loaded mineralized polymeric micelles (MPM@DOX) at physiological pH was efficiently inhibited, At an endosomal pH (pH 5.0), DOX release was facilitated due to rapid dissolution of the calcium phosphate (CaP). These results indicate that mineralized polymeric micelles are potentially as robust carriers that can release DOX at specific sites under mild acidic conditions, such as in an extracellular matrix of tumor tissue and intracellular cell compartments. PMID:25037334

Lv, Yan; Huang, Hailong; Yang, Bohan; Liu, Huan; Li, Yapeng; Wang, Jingyuan



Long Term Electrochemical Behavior of Creviced and Non-Creviced Alloy 22 in CaCl2 + Ca(NO3)2 Brines at 155?C  

SciTech Connect

Alloy 22 is a nickel base alloy highly resistant to all forms of corrosion. In very aggressive conditions (e.g. hot concentrated chloride containing brines) Alloy 22 could suffer localized attack, namely pitting and crevice corrosion. Chloride ion is known to be the most detrimental aggressive agent for Alloy 22 and is able to promote crevice corrosion when tight crevices exist in hot chloride containing solutions of different concentrations. Nitrate ion is an effective inhibitor of chloride induced crevice corrosion when present in a high enough [NO{sub 3}{sup -}]/[Cl{sup -}] ratio. The occurrence of localized corrosion in a given environment is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}) that the alloy may establish in the studied environment. If E{sub corr} is equal or higher than E{sub crit}, localized corrosion may be expected. This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of Alloy 22 specimens in 18 m CaCl{sub 2} + 9 m Ca(NO{sub 3}){sub 2} and 18 m CaCl{sub 2} + 0.9 m Ca(NO{sub 3}){sub 2} brines at 155 C. Two types of specimens were used, polished as-welded (ASW) creviced and non-creviced specimens and as-welded plus solution heat-treated (ASW+SHT) creviced specimens. The latter contained the black annealing oxide film on the surface. Results show that, in a few immersion days E{sub corr} reached a stable value higher than the open circuit potential of a platinum electrode in 18 m CaCl{sub 2} + 9 m Ca(NO{sub 3}){sub 2} for all specimens tested. Specimens tested in this solution did not suffer any type of localized attack. On the other hand, E{sub corr} showed oscillations of up to 600 mV in 18 m CaCl{sub 2} + 0.9 m Ca(NO{sub 3}){sub 2} during the entire immersion period. These oscillations were due to pitting corrosion development. Crevice corrosion was not observed in any testing case. Corrosion rates for specimens in the latter solution ([NO{sub 3}{sup -}]/[Cl{sup -}] = 0.05) were one order of magnitude higher than for specimens in the second one ([NO{sub 3}{sup -}]/[Cl{sup -}] = 0.5). Nitrate showed to be able to inhibit localized attack even in hot concentrated chloride brines when present in a ratio of [NO{sub 3}{sup -}]/[Cl{sup -}] = 0.5. Localized corrosion occurred only in condition where E{sub corr} > E{sub crit}.

Rodr?guez, M A; Stuart, M L; Rebak, R B



Regulation of the sodium/potassium/chloride cotransporter by calcium and cyclic AMP in cultured vascular smooth muscle cells  

SciTech Connect

The activity of the Na/K/Cl cotransporter in smooth muscle cells cultured from rat aorta was assayed by measuring the initial rate of furosemide-inhibitable /sup 86/Rb influx or efflux. Five uM furosemide or 0.2 uM bumetanide inhibited influx by 50%. Furosemide-inhibitable /sup 86/Rb influx depended on the presence of all 3 ions in the external medium. The dependence on Na and K was hyperbolic with apparent Km values of 45 and 5 mM, respectively. The dependence on Cl was sigmoidal. Assuming a stoichiometry of 1:1:2 for Na:K:Cl, a Km for Cl of 60 mM was obtained from a Hofstee plot of the data. Rapidly growing cells had 3 fold higher cotransport activity than quiescent cells. Angiotensin II (ANG) stimulated furosemide-inhibitable /sup 86/Rb efflux by 2 fold. An ANG receptor antagonist prevented ANG from increasing cotransport activity. Two calcium ionophores, A23187 and ionomycin, increased cotransport activity by 2 fold. Phorbol myristate acetate had no effect on cotransport activity. Isoproterenol, dibutyryl cyclic AMP, cholera toxin, or methylisobutylxanthine inhibited furosemide-sensitive /sup 86/Rb influx by 35 to 50%. From these findings they conclude that increasing cytoplasmic free calcium stimulates cotransport activity, whereas increasing cellular cyclic AMP inhibits the cotransporter.

Higgins, B.L.; Smith, L.; Smith, J.B.



Internal pressures and molecular dimensions in aqueous solutions of some chlorides  

NASA Technical Reports Server (NTRS)

On the basis of measurements of the velocity of ultrasounds in aqueous solutions of some alkaline-earth chlorides (MgCl2, CaCl2, BaCl2) the concentration and temperature dependences of the internal pressure were determined. Using these results, as well as surface tension measurements, the mean diameters of the molecular species as a function of concentration and temperature, were determined.

Auslaender, D.; Lenart, I.; Rus, E.; Ciupe, A.



Inkjet fabrication and characterization of calcium alginate microcapsules  

Microsoft Academic Search

The present work describes a method for producing calcium alginate hydrogel microcapsules in the size range of 5070?m by means of a piezoelectric drop-on-demand inkjet device. Particles were prepared by emitting droplets of 0.5% and 1% (w\\/w) sodium alginate solutions into a magnetically stirred pool of CaCl2 solution of variable viscosity ranging from 1 to 100mPas. The effect of viscosity

Ji? Dohnal; Frantiek t?pnek



Microencapsulation of yeast cells in the calcium alginate membrane  

Microsoft Academic Search

Cells of Saccharomyces cerevisiae (ATCC 24858) were encapsulated in the calcium alginate membrane and cultured. Swelling of the capsule was prevented by adding 0.2 g CaCl2 to 1 L growth medium. The dry cell concentration based on the inner volume of the capsule reached 309 g\\/L, which was much higher than could be obtained by cell entrapment. All the cells

Soo Hwan Cheong; Joong Kon Park; Beom Soo Kim; Ho Nam Chang



Effect of cadmium on cytogenetic toxicity in hairy roots of Wedelia trilobata L. and their alleviation by exogenous CaCl2.  


Effects of cadmium (Cd) alone and in combination with calcium on mitosis and chromosomal aberration in the hairy root tips of Wedelia trilobata were investigated. The results showed that Cd concentrations below 50?mol/L had a lesser or even a promoting effect on the mitotic index (MI) and the rate of chromosomal aberration in hairy root tips, while those higher than 100?mol/L significantly decreased the MI and gradually stimulated the rate of chromosomal aberrations with prolonged time and increasing concentrations of Cd. Concentrations of 50?mol/L Cd mainly induced C-mitosis, while more than 100?mol/L Cd mainly caused chromosome breakage and chromosome adhesion in hairy root tip cells. When cultured with 300?mol/L Cd, micronuclei were only observed in the interphase, middle, and late phase of hairy root tip cells. Compared with untreated controls, exogenous calcium had an alleviating effect on Cd-induced cytotoxicity by effectively enhancing the MI and reducing the rate of chromosomal aberration in root tip cells. The results presented here provide evidence that W. trilobata hairy roots with rapid autonomous growth could be used as a sensitive tool for monitoring and evaluation of Cd pollution in the environment. PMID:23917739

Shi, He Ping; Zhu, Yuan Feng; Wang, Yun Ling; Tsang, Po Keung Eric



Protective Effect of Retinal Ischemia by Blockers of Voltage-dependent Calcium Channels and Intracellular Calcium Stores  

Microsoft Academic Search

In the present study, the neuroprotective effect of blockers of voltage-dependent calcium channels (VDCC) and intracellular\\u000a calcium stores on retinal ischemic damage induced by oxygen deprivation-low glucose insult (ODLG) was investigated. Retinal\\u000a damage induced by ODLG was dependent on the calcium concentration in the perfusion medium. When incubated in medium containing\\u000a 2.4mM CaCl2, cell death in ischemic retinal slices treated

Pindaro Dias Massote; Ana Cristina Nascimento Pinheiro; Cristina Guatimosim Fonseca; Marco Antonio Mximo Prado; Andr L. S. Guimares; Andr R. Massensini; Marcus Vinicius Gomez



The Porcine Chloride Channel Calcium-Activated Family Member pCLCA4a Mirrors Lung Expression of the Human hCLCA4  

PubMed Central

Pig models of cystic fibrosis (CF) have recently been established that are expected to mimic the human disease closer than mouse models do. The human CLCA (originally named chloride channels, calcium-activated) member hCLCA4 is considered a potential modifier of disease severity in CF, but its murine ortholog, mCLCA6, is not expressed in the mouse lung. Here, we have characterized the genomic structure, protein processing, and tissue expression patterns of the porcine ortholog to hCLCA4, pCLCA4a. The genomic structure and cellular protein processing of pCLCA4a were found to closely mirror those of hCLCA4 and mCLCA6. Similar to human lung, pCLCA4a mRNA was strongly expressed in porcine lungs, and the pCLCA4a protein was immunohistochemically detected on the apical membranes of tracheal and bronchial epithelial cells. This stands in sharp contrast to mouse mCLCA6, which has been detected exclusively in intestinal epithelia but not the murine lung. The results may add to the understanding of species-specific differences in the CF phenotype and support the notion that the CF pig model may be more suitable than murine models to study the role of hCLCA4.

Plog, Stephanie; Grotzsch, Tanja; Klymiuk, Nikolai; Kobalz, Ursula; Gruber, Achim D.



Effect of copper chloride exposure on the membrane potential and cytosolic free calcium in primary cultured chicken hepatocytes.  


This study was conducted to examine the effects of copper on membrane potential and cytosolic free calcium in isolated primary chicken hepatocytes which were exposed to different concentration of Cu(2+) (0, 10, 50, 100 ?M) or a mixture of Cu(2+) and vitamin C (50 and 50 ?M, respectively). Viability, membrane potential, and cytosolic free Ca(2+) of monolayer cultured hepatocytes were investigated at the indicated time point. Results showed that, among the different concentrations of Cu(2+) exposure, the viability of hepatocytes treated with 100 ?M Cu(2+) was the worst at the 12th and 24th hours. The effects of Cu(2+) on viability and proliferation were time and dose dependent. Further investigation indicated that Cu(2+) exposure significantly enhanced cytosolic free Ca(2+) in hepatocytes, compared to that in control group, at the 24th hour. Meanwhile, membrane potential was noticeably reduced in hepatocytes increasing concentration of Cu(2+). Taking these results together, we have shown that Cu(2+) can cause toxicity to primary chicken hepatocytes in excessive dose and the effect of Cu(2+) exposure on membrane potential is not site specific, which is probably mediated by the changes of cytosolic free Ca(2+). PMID:22447273

Jia, Xuexia; Chen, Long; Li, Jingtao; Su, Rongsheng; Shi, Dayou; Tang, Zhaoxin



Long-Term Corrosion Potential Behavior of Alloy 22 in Hot 5 m CaCl2 + 5 m Ca(NO3)2 Brines  

SciTech Connect

Alloy 22 is a nickel base alloy highly resistant to all forms of corrosion. In very aggressive conditions (e.g. hot concentrated chloride containing brines) Alloy 22 could suffer localized attack, namely pitting and crevice corrosion. The occurrence of localized corrosion in a given environment is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}) that the alloy may establish in the studied environment. If E{sub corr} is equal or higher than E{sub crit}, localized corrosion may be expected. This paper discusses the evolution of E{sub corr} of Alloy 22 specimens in 5 m CaCl{sub 2} + 5 m Ca(NO{sub 3}){sub 2} brines at 100 C and 120 C. Two types of specimens were used, polished as-welded (ASW) creviced and noncreviced specimens and as-welded plus solution heat-treated (ASW+SHT) creviced specimens. The latter contained the black annealing oxide film on the surface. Results show that, for all types of Alloy 22 specimens the E{sub corr} was higher at 120 C than at 100 C, probably because a more protective film formed at the higher temperature. Specimens with the black oxide film on the surface showed more oscillations in the potential. None of the tested specimens suffered crevice corrosion probably because of the relatively high concentration of nitrate in the electrolyte, R = [NO3]/[Cl] = 1.

Rodriguez, M A; Carranza, R M; Stuart, M L; Rebak, R B



Dechlorination reaction of hexachlorobenzene with calcium oxide at 300-400 degrees C.  


Hexachlorobenzene (HCB) was thermally treated with calcium oxide (CaO) at 300-400 degrees C. Analyses of chloride ions and residual HCB confirmed that a dechlorination reaction had occurred. The dechlorination mechanism was investigated with a series of analytical methods including X-ray fluorescence (XRF), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The final products detected were CaCO(3) by XRD and Raman spectroscopy, amorphous carbon by Raman spectroscopy, and CaCl(2) by XPS. The newly produced species of CaCO(3) and amorphous carbon were thought to be the ultimate fate of the C element of HCB. After identification of the final dechlorination products, we can conclude that the reaction of HCB with CaO at 300-400 degrees C is through a dechlorination/polymerization pathway, which is induced by electron transfer. An overall reaction formula for HCB reaction with CaO was proposed and was energetically quite favorable. The results are helpful for the further comprehension of the reaction mechanism for thermal dechlorination of PCDD/Fs in CaO rich matrices. PMID:19380198

Gao, Xingbao; Wang, Wei; Liu, Xiao



Using a CD-like microfluidic platform for uniform calcium alginate drug carrier generation  

NASA Astrophysics Data System (ADS)

In this paper the manipulation of monodisperse Ca-alginate microparticles using a polymer-based CD-like microfluidic platform and a reaction of external gelation is presented. Our strategy was based on associating the rapid injection molding process for cross-junction microchannel with the sheath focusing effect to form uniform water-in-oil (w/o) emulsions. These fine emulsions, consisting of 1.5% w/v Na-alginate, were then dripped into an oil solution containing 20% w/v calcium chloride (CaCl2) to accomplish Ca-alginate microspheres in an efficient manner. We have demonstrated that one can control the size of Ca-alginate microparticles from 20 m to 50 m in diameter (with a variation less than 10%) by altering the relative sheath/sample flow rate ratio. Experimental data showed that for a given fixed dispersed phase flow (sample flow), the emulsion size decreased as the average velocity of the continuous phase (oil flow) increased. The proposed CD-like microfluidic platform is capable of generating relatively uniform microdroplets and has the advantages of active control of droplet diameter, simple and low cost process, and high throughput.

Liu, Ming-Kai; Huang, Keng-Shiang; Chang, Jia-Yaw; Wu, Chun-Han; Lin, Yu-Cheng



Effects of altering calcium in haemodiluted pump primes on sodium and potassium in children undergoing open-heart operations  

Microsoft Academic Search

SummaryThe effects of low or normal calcium ion concentrations in the haemodiluted prime on plasma levels and urinary excretion of\\u000a monovalent cations were contrasted in 32 children undergoing open-heart operations with cardiopulmonary bypass (CPB).\\u000a \\u000a In patients in whom ionic calcium had been maintained near normal during bypass (Groups B and D, CaCl2 in prime), the intra-operative incidence of hyperkalaemia and

A. E. Johnston; I. C. Radde; H. I. A. Nisbet; J. Taylor



[Alleviated affect of exogenous CaCl2 on the growth, antioxidative enzyme activities and cadmium absorption efficiency of Wedelia trilobata hairy roots under cadmium stress].  


In order to study the physiological mechanism of exogenous calcium on the toxicity of heavy metal cadmium (Cd) to Wedelia trilobata hairy roots, the effects of Cd alone, and in combination with different concentrations of Ca on growth, contents of soluble protein and malondialdehyde (MDA), activities of superoxide dismutase (SOD) and peroxidase (POD), Cd2+ absorption in W. trilobata hairy roots were investigated. Cd concentrations lower than 50 micromol/L enhanced the growth of hairy roots, while concentrations higher than 100 micromol/L inhibited growth, making the branched roots short and small, and also turning the root tips brown, even black. In comparison with the control (0 micromol/L Cd), the soluble protein content in hairy roots was found to increase when cultured with 10-50 micromol/L Cd, and decrease when exposed to a cadmium concentration higher than 100 micromol/L Cd. In addition, the activities of POD and SOD activity and MDA content were significantly higher than the control. Compared to the control (hairy roots cultured without 10-30 mmol/L Ca), 100 micromol/L Cd or 300 micromol/L Cd in combination with 10-30 mmol/L Ca resulted in increased growth, causing the main root and secondary roots thicker and also an increase in soluble protein content. On the contrary, MDA content and POD and SOD activities decreased. Quantitative analysis by Atomic Absorption Spectrophotometry showed that W. trilobata hairy roots can absorb and adsorb heavy metal Cd in the ionic form of Cd2+. The maximum content of Cd2+ absorbed by the hairy roots was obtained with a concentration 100 micromol/L Cd2+ while that of Cd2+ adsorbed by hairy roots was achieved with a concentration of 300 micromol/L Cd2+. The exogenous addition of 10-30 mmol/L Ca2+ was found to reduce the absorption, adsorption of Cd2+ and the toxicity of Cd significantly. This reduction in toxicity was caused by the reduction in the absorption of Cd and decreasing the lipid peroxidation through regulating the activities of antioxidant enzymes SOD and POD in the hairy roots. PMID:23016311

Shi, Heping; Wang, Yunling; Tsang, PoKeung Eric; Chan, LeeWah Andrew



Influence of pH and Chloride-Based Metal Salts on Coagulation\\/Dispersion Behavior of Talc Suspension  

Microsoft Academic Search

In this study, the coagulation behavior of talc suspensions in the presence and absence of chloride-based metal salts (NaCl, CaCl2 and AlCl3) at a constant (pH 4) and different pHs was assessed by sedimentation tests and zeta potential (ZP) measurements. In addition, the pH-dependent dissolution experiments were performed on the talc powder in water. To evaluate the results of the

Bahri Ersoy



P108Two sides of the same coin: integrative role of the calcium-activated chloride channels in the ventricular myocardium.  


As a part of the transient outward current, the calcium-activated chloride current (ICl(Ca)) is involved in the action potential (AP) repolarization, however, its possible contribution to formation of delayed afterdepolarizations and thus life threatening arrhythmias was also suggested, especially in cardiac pathologies e.g. cardiac failure and myocardial hypertrophy, where intracellular Ca2+ concentration increases. The aim of this work was to study the profile of ICl(Ca) during AP in various regions of ventricular muscle. Experiments were performed using conventional microelectrode, whole-cell patch-clamp and AP-clamp techniques at 37 C degrees on isolated canine ventricular myocytes. ICl(Ca) was studied by an inhibitor, anthracene-9-carboxylic acid (9-AC, 0.5 mM). Under voltage-clamp conditions ICl(Ca) started to activate at -20 mV and peaked at +60 mV (2.110.35 pA/pF, n=8), while in the presence of BAPTA (10 mM), a calcium chelating agent, the current was abolished indicating its calcium-activated feature. ICl(Ca) amplitude increased progressively with higher stimulatory frequencies. AP measurements with sharp microelectrodes confirmed this property as 9-AC reduced the size of the AP notch and elevated the mid-plateau potential in a direct rate-dependent manner. However, these changes resulted in a reverse rate-dependent AP lengthening in midmyocardial and subendocardial cells (+24.343.26 ms and +15.852.14 ms at 1 Hz, n=15 and n=7, respectively). On the contrary, under 2 Hz stimulatory frequencies a progressive AP shortening was observed in subepicardial myocytes (-13.187.50 ms at 1 Hz, n=7). AP-clamp experiments revealed an early narrow outward and a late inward current peak after the application of 9-AC (+1.150.11 pA/pF and -0.180.04 pA/pF, respectively, n=13). Similar peak current amplitudes were measured in every transmural heart regions. Beta-adrenergic activation (by isoproterenol, 10 nM) nearly doubled the amplitudes of both part of ICl(Ca) (2.430.11 pA/pF and -0.310.10 pA/pF, n=4). Furthermore, early afterdepolarizations appeared following ICl(Ca) blockade at low heart rates, especially during beta-adrenergic stimulation. These findings suggest that the different contribution of ICl(Ca) to the AP generation in different cardiac regions is a consequence of the characteristic shape of the given AP. A selective ICl(Ca) blocking agent could be beneficial in Ca2+-overloaded cells by decreasing the development of delayed afterdepolarizations, but it could be harmful by increasing the transmural dispersion of repolarization and provoking early afterdepolarizations. PMID:25020527

Hegyi, B; Vaczi, K; Ruzsnavszky, F; Kistamas, K; Gonczi, M; Horvath, B; Banyasz, T; Magyar, J; Nanasi, P; Szentandrassy, N



Mechanism of Friedel's salt formation in cements rich in tri-calcium aluminate  

Microsoft Academic Search

In the present investigation, based on pore solution analyses, the mechanisms of Friedel's salt formation and the related chemical processes taking place in mortar due to chloride binding are dealt with. Pore solutions from mortars containing NaCl and CaCl2 added during mixing were analyzed. Based on the results it is proposed that in the presence of NaCl the Friedel's salt

A. K. Suryavanshi; J. D. Scantlebury; S. B. Lyon



Effect of Azadirachta indica (neem), sodium thiosulphate and calcium chloride on changes in nitrogen transformations and inhibition of nitrification in soil incubated under laboratory conditions.  


A laboratory experiment was conducted to examine the effects of nitrification inhibitors (NIs) neem seed-cake (Azadirachta indica) (NSC), sodium thiosulphate (Na?S?O?) and calcium chloride (CaCl?) on changes in NH?(+)?N, inhibition of nitrification and recovery of applied nitrogen (N) in soil. Surface soil samples of 0-15 cm were collected from an arable field, amended with urea N (UN) at the rate 200 mg N kg?, UN+NSC, UN+Na?S?O? and UN+CaCl? and incubated at 22C periodically over 50 d. Soil without any amendment was used as check (control). Results indicated that more than 58% of N applied as NH?? disappeared over a period of 50 d from the soil mineral-N pool. Some of this N (21%) was accumulated as NO??-N while the remaining N was unaccounted for. Addition of nitrification inhibitors NSC, Na?S?O?, and CaCl? resulted in a decrease in the extent of NH?(+) disappearance by 35%, 44% and 30%, respectively. In the treatment receiving UN alone, 56 mg NO??-N kg? was accumulated over 50 d (maximum 93 mg kg?) indicated an active nitrification. Application of nitrification inhibitors NSC, Na?S?O?, and CaCl? with UN inhibited nitrification by 54%, 64%, and 59%, respectively. Apparent N recovery (ANR) in the treatment receiving UN alone was 63% that substantially increased to 83%, 89% and 76% in the treatments receiving UN+NSC, UN+Na?S?O?, and UN+CaCl?, respectively indicating 32%, 41% and 20% increase in N recovery. Among three NIs tested, Na?S?O? proved superior in inhibiting nitrification and increasing ANR. The study demonstrated that application of NSC, Na?S?O?, and CaCl? which are cheap and easily available NIs inhibited nitrification and improved N recovery efficiency of applied N in an arable soil very effectively. It is suggested that these inhibitors should be tested under field conditions for increasing NUE and improving crop productivity. PMID:21146192

Abbasi, M Kaleem; Hina, Munazza; Tahir, Majid Mahmood



Characteristics of the interaction of calcium with casein submicelles as determined by analytical affinity chromatography  

SciTech Connect

Interaction of calcium with casein submicelles was investigated in CaCl2 and calcium phosphate buffers and with synthetic milk salt solutions using the technique of analytical affinity chromatography. Micelles that had been prepared by size exclusion chromatography with glycerolpropyl controlled-pore glass from fresh raw skim milk that had never been cooled, were dialyzed at room temperature against calcium-free imidazole buffer, pH 6.7. Resulting submicelles were covalently immobilized on succinamidopropyl controlled-pore glass (300-nm pore size). Using 45Ca to monitor the elution retardation, the affinity of free Ca2+ and calcium salt species was determined at temperatures of 20 to 40 degrees C and pH 6.0 to 7.5. Increasing the pH in this range or increasing the temperature strengthened the binding of calcium to submicelles, similar to previous observations with individual caseins. However, the enthalpy change obtained from the temperature dependence was considerably greater than that reported for alpha s1- and beta-caseins. Furthermore, the elution profiles for 45Ca in milk salt solutions were decidedly different from those in CaCl2 or calcium phosphate buffers and the affinities were also greater. For example, at pH 6.7 and 30 degrees C the average dissociation constant for the submicelle-calcium complex is 0.074 mM for CaCl2 and calcium phosphate buffers, vs 0.016 mM for the milk salt solution. The asymmetric frontal boundaries and higher average affinities observed with milk salts may be due to binding of calcium salts with greater affinity in addition to the binding of free Ca2+ in these solutions.

Jang, H.D.; Swaisgood, H.E. (North Carolina State Univ. (USA))



Crystallization and Transformation Mechanism of Calcium Carbonate Polymorphs and the Effect of Magnesium Ion  

Microsoft Academic Search

The crystallization of calcium carbonate was carried out by mixing CaCl2 and Na2CO3 solutions. The morphology of precursor formed prior to the nucleation of the polymorphous crystals (calcite and vaterite) varies depending on the feed concentration. The faster nucleation rate of polymorphous crystals in 0.2 mol\\/L than in 0.05 mol\\/L solution results in the prompt disappearance of the precursor at

Mitsutaka Kitamura



Use of electrochemical techniques for the study of solubilization processes of ceriumoxide compounds and recovery of the metal from molten chlorides  

Microsoft Academic Search

This work presents a study on the chemical and electrochemical properties of CeCl3 in two molten chloride mixtures with different oxoacidity properties, the eutectic LiClKCl at 723 K and the equimolar CaCl2NaCl melt at 823 K. The EpO2? (potentialacidity) diagram for CeO compounds stable in both melts has been constructed by combining both theoretical and experimental data. The stable oxidation

Y. Castrillejo; M. R. Bermejo; R. Pardo; A. M. Mart??nez



Preparation, Mass Diffusion, and Biocompatibility Analysis of Porous-Channel Controlled Calcium-Alginate-Gelatin Hybrid Microbeads for In Vitro Culture of NSCs.  


The Ca-alginate/gelatin (CAG) microbeads were prepared and evaluated through assays for their mechanical strength, permeability, and the feasibility as a cell carrier for in vitro culture of neural stem cells. The effects of different concentrations of sodium alginate, gelatin, and calcium chloride on the mechanical strength of CAG microbeads were determined using a self-made puncture force tester. Following this, the microbeads were immersed in DMEM media for a specified period to test its decay resistance. A diffusion model including a calculation formula of diffusion coefficient was built to investigate the diffusion of glucose and bovine serum albumin (BSA) through the wall of the microbeads. Furthermore, the feasibility of the microbeads for in vitro culture was identified using neural stem cells from Kunming mouse. Through a systematic approach and comprehensive analysis, the optimal gelatin conditions for microbead preparation were determined; the final combination of parameters of 1.5% (wt%) sodium alginate (SA), 0.5% (wt%) gelatin, and 4% (wt%) CaCl2 were the best conditions for NSC cultures. This experiment demonstrated that CAG microbeads had good cytocompatibility that made it suitable for the culture and successfully maintained stemness of neural stem cells. PMID:24728762

Song, Kedong; Li, Liying; Li, Ruipeng; Lim, Mayasari; Liu, Peng; Liu, Tianqing



Calcium fluoride window mounting  

SciTech Connect

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

Berger, D.D.



Use of a D-optimal mixture design to estimate the effects of diverse chloride salts on the growth parameters of Lactobacillus pentosus.  


The effects of NaCl, KCl, CaCl(2), and MgCl(2) and their mixtures on the ionic strength (IS) of the medium and the growth parameters of Lactobacillus pentosus were studied by means of a D-optimal mixture experimental design with constrains (total salt concentrationCaCl(2)>NaCl>KCl. Within the experimental region, the lag phase duration (lambda) was mainly affected by NaCl and CaCl(2) and the interaction KCl with MgCl(2). The maximum specific growth rate (mu(max)) decreased as NaCl (the highest effect), CaCl(2), and MgCl(2) increased (regardless of the presence or not of previous NaCl); low KCl concentrations had a stimulating effect on mu(max), but its overall effect showed a similar trend to the other salts. The maximum population reached (N(max)) was the least affected parameter and decreased as NaCl and CaCl(2) concentrations increased regardless of the presence of the other salts. The equations that expressed the growth parameters as a function of the diverse chloride salts, within the limits assayed, were developed and the corresponding z- and harmonic Z-values were estimated. PMID:19376461

Arroyo-Lpez, F N; Bautista-Gallego, J; Chiesa, A; Durn-Quintana, M C; Garrido-Fernndez, A



Experimental evaluation of water mist with metal chloride additives for suppressing CH4/air cup-burner flames  

NASA Astrophysics Data System (ADS)

In order to investigate the fire suppression effectiveness of water mist with metal chloride additives, ultrafine water mists of these salts with diameters about 10?m were introduced into CH4/air non-premixed flame in the cup burner. Results showed that these droplets hard to make itself to the flame front under the cup burner flow conditions functioned as a carrier of the vaporized solid particles or its decomposed materials. The metal chloride improved fire suppression efficacy of water mist which were affected by the type and concentration of metal chloride. On a mass basis, there is a fire suppression effectiveness relationship of MgCl2chlorides improves as the concentration of metal chlorides increase. However, upper additive limits exist due to the associated limiting vapour pressure of the additive.

Liu, Jianghong; Cong, Beihua



Biomimetic calcium phosphate crystal mineralization on electrospun cellulose-based scaffolds.  


Novel cellulose based-scaffolds were studied for their ability to nucleate bioactive calcium phosphate crystals for future bone healing applications. Cellulose-based scaffolds were produced by electrospinning cellulose acetate (CA) dissolved in a mixture of acetone/dimethylacetamide (DMAc). The resulting nonwoven CA mats containing fibrils with diameters in the range of 200 nm to 1.5 ?m were saponified by NaOH/ethanol for varying times to produce regenerated cellulose scaffolds. Biomimetic crystal growth nucleated from the fiber surface was studied as a function of surface chemistry. Regenerated cellulose scaffolds of varying treatments were soaked in simulated body fluid (SBF) solution. Scaffolds that were treated with CaCl(2), a mixture of carboxymethyl cellulose (CMC) and CaCl(2), and NaOH and CaCl(2), were analyzed using X-ray photoelectron spectroscopy, X-ray powder diffraction, and scanning electron microscopy to understand the growth of bioactive calcium phosphate (Ca-P) crystals as a function of surface treatment. The crystal structure of the nucleated Ca-P crystals had a diffraction pattern similar to that of hydroxyapatite, the mineralized component of bone. The study shows that the scaffold surface chemistry can be manipulated, providing numerous routes to engineer cellulosic substrates for the requirements of scaffolding. PMID:21355545

Rodrguez, Katia; Renneckar, Scott; Gatenholm, Paul



The Effect of Sodium Chloride on the Corrosion of Concrete Reinforcing Steel and on the pH of Calcium Hydroxide Solution.  

National Technical Information Service (NTIS)

The electrical half-cell potential measurement is a valid technique for detecting the existence of corrosion in the steel reinforcement of chloride-containing concrete. The voltage which it measures is not directly affected by the presence of sodium chlor...

H. A. Berman



Hydrothermal Formation Of Hemi-hydrate Calcium Sulfate Whiskers In The Presence Of Additives  

NASA Astrophysics Data System (ADS)

The influence of addictives on the hydrothermal formation of hemi-hydrate calcium sulfate (CaSO4.0.5H2O) whiskers were discussed in this paper, using CaCl2 and Na2SO4 as the reactants. The presence of NaCl, CaCl2 or Na2SO4 increased the concentrations of Ca2+ and SO42-, leading to the formation of CaSO4.0.5H2O whiskers with aspect ratio lower than 50. The one dimensional growth of CaSO4.0.5H2O whiskers was enhanced in water with no additives owing to the low super-saturation, leading to the formation of uniform whiskers with a length of 200-2000 ?m and an aspect ratio higher than 100.

Luo, K. B.; Li, C. M.; Xiang, L.; Li, H. P.; Ning, P.



Synthesis and thermal properties of strontium and calcium peroxides  

NASA Technical Reports Server (NTRS)

A practical synthesis and a discussion of some chemical properties of pure strontium peroxide and calcium peroxide are presented. The general synthesis of these peroxides involves precipitation of their octahydrates by addition of H2O2 to aqueous ammoniacal Sr(NO3)2 or CaCl2. The octahydrates are converted to the anhydrous peroxides by various dehydration techniques. A new x-ray diffraction powder pattern for CaO2 x 8H2O is given from which lattice parameters a=6.212830 and c=11.0090 were calculated on the basis of the tetragonal crystal system.

Philipp, Warren H.; Kraft, Patricia A.



depth measurement temperature measurement pressure measurement conductivity measurement (Salinity measurement TDS measurement) Oxygen Concentration measurement (Oxygen saturation measurement) pH-value measurement Red-ox-potential ORP measurement turbidity measurement (TSS measurement) measurement ion selective electrode (nitrate chloride ammonium potassium calcium sodium fluoride gas ammonia) fluorescence measurements (chlorophyll a cyanobacteria rhodamine ) optical oxygen measurements.  

EPA Pesticide Factsheets

Did you mean: depth measurement temperature measurement pressure measurement conductivity measurement (Salinity measurement TDS measurement) Oxygen Concentration measurement (Oxygen saturation measurement) pH-value measurement Red-ox-potential ORP measurement turbidity measurement (TSS measurement) measurement ion selective electrode (nitrate chloride ammonium potassium calcium sodium fluoride gas ammonia) fluorescence measurements (chlorophyll a cyanobacteria rhodamine ) optical oxygen measurements. ?


Cobalt-sensitive biphasic uptake of calcium ions in potassium-depolarized smooth muscle.  


Isolated longitudinal muscle from guinea-pig ileum was immersed in a calcium-depleted, high-potassium medium for 10 min and then induced to contract by adding 1.8 mM CaCl2. It exhibited a biphasic response that consisted of an initial, rapid, transitory contraction--the phasic response--followed by a slower more sustained contraction--the tonic response. 45Ca uptake was also measured. Only that fraction of the accumulated calcium that could be inhibited by cobalt ion was considered to be intracellular calcium. The data showed that the phasic contraction was accompanied by a brief, rapid uptake of calcium ions and the tonic response was accompanied by a slower, more prolonged uptake of calcium ions. When the muscle, after undergoing an initial biphasic contraction, was reincubated in the calcium-depleted, high-potassium medium for 70 to 80 min, the phasic contraction that it exhibited upon the readdition of 1.8 mM CaCl2 remained unaltered, but the tonic contraction was delayed and substantially diminished. Under these conditions, the rate of the initial brief, rapid uptake of calcium was reduced by 20%, whereas the subsequent slow, prolonged uptake of calcium was measurably delayed and its rate was reduced by an average of 31.4%. Calcium pulse experiments showed that variations in the rate of calcium uptake were due primarily to variations in the rate of the inward movement of calcium ions. The results suggest that the biphasic mechanical response is a reflection of a biphasic influx of calcium ions in the potassium-depolarized longitudinal muscle. PMID:2579232

Little, S A; Teaf, E; Hurwitz, L



Calcium transport abnormality in uremic rat brain synaptosomes.  


Brain calcium is elevated in patients and laboratory animals with uremia. The significance of this finding is unclear. We evaluated calcium transport in brain of both normal and acutely uremic rats (blood urea nitrogen = 250 mg/dl) by performing studies in synaptosomes from rat brain cerebral cortex. Synaptosomes are vesicular presynaptic nerve endings from brain that contain mitochondria and are metabolically active. Two mechanisms of calcium transport were evaluated using radioactive 45Ca++ as a tracer. Both mechanisms were evaluated in the absence of exogenously administered parathyroid hormone (PTH). We first evaluated Na+-Ca++ exchange in vesicles that were loaded with NaCl in an external media containing 10 microM CaCl2. Both initial rates of calcium transport and equilibrium levels of calcium accumulation in synaptosomes prepared from uremic rats were significantly greater (P less than 0.005) than in normal. To assess calcium efflux, ATP-dependent calcium uptake (1 mM ATP) was studied in inverted plasma membrane vesicles loaded with KCl. In the uremic synaptosomes, a significant increase (P less than 0.005) in ATP-dependent calcium uptake was observed as compared with the normal. These studies show that (a) Calcium accumulation via the Na+-Ca++ exchanger is increased in synaptosomes prepared from uremic rat brain. (b) Calcium influx into inverted plasma membrane vesicles from uremic rats via the ATP-dependent calcium transport mechanism is increased when compared with normal. (c) The increased calcium accumulation in uremia by both Na+-Ca++ exchange and ATP-dependent calcium transport mechanism appears to be a result of increased synaptosomal membrane permeability to calcium. Both these abnormalities of calcium transport in uremia would tend to increase brain extracellular calcium in vivo. The defects observed in uremia do not appear to be readily reversible, and the relationship to PTH is presently unclear. These abnormalities may affect neurotransmission in the uremic state. PMID:4056053

Fraser, C L; Sarnacki, P; Arieff, A I



A glass-encapsulated calcium phosphate wasteform for the immobilization of actinide-, fluoride-, and chloride-containing radioactive wastes from the pyrochemical reprocessing of plutonium metal  

SciTech Connect

The presence of halide anions in four types of wastes arising from the pyrochemical reprocessing of plutonium required an immobilization process to be developed in which not only the actinide cations but also the halide anions were immobilized in a durable waste form. At AWE, we have developed such a process using Ca3(PO4)2 as the host material. Successful trials of the process with actinide- and Cl-bearing Type I waste were carried out at PNNL where the immobilization of the waste in a form resistant to aqueous leaching was confirmed. Normalized mass losses determined at 40C and 28 days were 12 x 10-6 g?m-2 and 2.7 x 10-3 g?m-2 for Pu and Cl, respectively. Accelerated radiation-induced damage effects are being determined with specimens containing 238Pu. No changes in the crystalline lattice have been detected with XRD after the 239Pu equivalent of 400 years ageing. Confirmation of the process for Type II waste (a oxyhydroxide-based waste) is currently underway at PNNL. Differences in the ionic state of Pu in the four types of waste have required different surrogates to be used. Samarium chloride was used successfully as a surrogate for both Pu(III) and Am(III) chlorides. Initial investigations into the use of HfO2 as the surrogate for Pu(IV) oxide in Type II waste indicated no significant differences.

Donald, Ian W.; Metcalfe, Brian; Fong, Shirley K.; Gerrard, Lee A.; Strachan, Denis M.; Scheele, Randall D.



EDTA-insoluble, calcium-binding proteoglycan in bovine bone  

NASA Technical Reports Server (NTRS)

A calcium ion precipitable, trypsin-generated proteoglycan fragment has been isolated from the demineralized, EDTA-insoluble matrices of bone. The demineralized matrix was completely digested with trypsin, increasing concentrations of CaCl2 were added to the supernatant, and the resulting precipitates were analyzed. The amount of precipitate gradually increased with higher concentrations of calcium and was reversibly solubilized by EDTA. After molecular sieve and anion exchange chromatography, a proteoglycan-containing peak was obtained. Immunochemical analysis showed that this peak contained chondroitin 4-sulfate and possibly keratan sulfate. Amino acid analysis showed that this proteoglycan contained high amounts of aspartic acid/asparagine (Asx), serine (Ser), glutamic acid/glutamine (Glx), proline (Pro), and glycine (Gly); however, it contained little leucine (Leu) which suggests that it is not a member of the leucine-rich small proteoglycan family. In addition, significant amounts of phosphoserine (P-Ser) and hydroxyproline (Hyp) were identified in hydrolysates of this fraction. A single band (M(r) 59 kDa) was obtained on SDS-PAGE that stained with Stains-all but not with Coomassie Brilliant Blue R-250. If bone powder was trypsinized prior to demineralization, this proteoglycan-containing fraction was not liberated. Collectively, these results indicate that a proteoglycan occurs in the demineralized matrix that is precipitated with CaCl2 and is closely associated with both mineral and collagen matrices. Such a molecule might facilitate the structural network for the induction of mineralization in bone.

Hashimoto, Y.; Lester, G. E.; Caterson, B.; Yamauchi, M.



Caffeine, urinary Calcium, Calcium Metabolism and Bone1'2  

Microsoft Academic Search

Oral doses of caffeine increase the urinary excretion of calcium, magnesium, sodium and chloride for at least 3 h after consumption. The hypercalciuric effect can be blocked by adenosine receptor agonists. The effect is proportional to dose per lean body mass and no adaptation to the urinary losses occurs with continuing consumption of caffeine. Uncompensated losses of calcium would be



Electrodialysis of calcium and carbonate high concentration solutions and impact on composition in cations of membrane fouling.  


Fouling, which is the accumulation of undesired solid materials at the phase interfaces of permselective membranes, is one of the major problems in electrodialysis. The objectives of the present work were to investigate the effect of the composition in calcium and carbonate of a model solution to be treated by conventional electrodialysis on their migration kinetics and the composition in cations of the membrane fouling. In the absence of sodium carbonate in the solution, no fouling was visually observed on anion-exchange membranes (AEM) and fouling was observed only at 1600 mg/L CaCl2 on cation-exchange membrane (CEM), while at only 800 mg/L CaCl2 with sodium carbonate, a deposit was observed on both membranes. This difference could be explained by the fact that carbonate has a high buffer capacity, and the time to reach pH 4.0 was then longer than the one without carbonate. Consequently, the migration of the ionic species was carried out over a longer period of time during ED treatment with sodium carbonate addition and in extent the demineralization rates were higher: 43 vs 86%. For treatment with sodium carbonate and 1600 mg/L CaCl2, the higher migration during ED treatment, increased the concentration of calcium, from 14.24 to 93.38 mg/g dry membrane and from 0.74 to 10.27 mg/g dry membrane for CEM and AEM, respectively. Due to the basic pH on the side of the membrane in contact with the NaCl solution, the calcium would precipitate to form calcium hydroxide on CEM while the calcium migrated through the CEM was blocked by the AEM where it formed another fouling. PMID:15897083

Bazinet, Laurent; Araya-Farias, Monica



Calcium channel antagonism by pizotifen.  

PubMed Central

Pizotifen is a clinically effective anti-migraine agent with potent anti-serotonin and anti-histamine properties. Pizotifen is equipotent in blocking contractions of the canine basilar artery induced by serotonin, norepinephrine or calcium chloride. As a result, the primary action of pizotifen in the canine basilar artery system appears to be calcium channel blockade and not selective antagonism of serotonin or norepinephrine. Calcium channel blocking ability may be related to the clinical efficacy of pizotifen in the treatment of migraine.

Peroutka, S J; Banghart, S B; Allen, G S



21 CFR 184.1229 - Calcium stearate.  

Code of Federal Regulations, 2013 CFR

...stearate. (a) Calcium stearate (Ca(C17 H35 COO)2 , CAS Reg. No. 1529-23-0) is the calcium salt of stearic acid derived from edible sources. It is prepared as a white precipitate by mixing calcium chloride and sodium stearate...



Chloride Test  


... Formal name: Chloride Related tests: Sodium , Potassium , Bicarbonate , Electrolytes , Comprehensive Metabolic Panel , Basic Metabolic Panel , Blood Gases ... if there is a problem with your body's electrolyte balance or acid-base balance and to monitor ...


Cesium Chloride  


... with heart rhythm, seizures, loss of consciousness, and electrolyte (blood chemistry) imbalances after taking cesium chloride. How ... with heart rhythm, seizures, loss of consciousness, and electrolyte imbalances. Cesium appears to take the place of ...


Prostaglandin E2 induces chloride secretion through crosstalk between cAMP and calcium signaling in mouse inner medullary collecting duct cells.  


Under conditions of high dietary salt intake, prostaglandin E2 (PGE2) production is increased in the collecting duct and promotes urinary sodium chloride (NaCl) excretion; however, the molecular mechanisms by which PGE2 increases NaCl excretion in this context have not been clearly defined. We used the mouse inner medullary collecting duct (mIMCD)-K2 cell line to characterize mechanisms underlying PGE2-regulated NaCl transport. When epithelial Na(+) channels were inhibited, PGE2 exclusively stimulated basolateral EP4 receptors to increase short-circuit current (Isc(PGE2)). We found that Isc(PGE2) was sensitive to inhibition by H-89 and CFTR-172, indicating that EP4 receptors signal through protein kinase A to induce Cl(-) secretion via cystic fibrosis transmembrane conductance regulator (CFTR). Unexpectedly, we also found that Isc(PGE2) was sensitive to inhibition by BAPTA-AM (Ca(2+) chelator), 2-aminoethoxydiphenyl borate (2-APB) (inositol triphosphate receptor blocker), and flufenamic acid (FFA) [Ca(2+)-activated Cl(-) channel (CACC) inhibitor], suggesting that EP4 receptors also signal through Ca(2+) to induce Cl(-) secretion via CACC. Additionally, we observed that PGE2 stimulated an increase in Isc through crosstalk between cAMP and Ca(2+) signaling; BAPTA-AM or 2-APB inhibited a component of Isc(PGE2) that was sensitive to CFTR-172 inhibition; H-89 inhibited a component of Isc(PGE2) that was sensitive to FFA inhibition. Together, our findings indicate that PGE2 activates basolateral EP4 receptors and signals through both cAMP and Ca(2+) to stimulate Cl(-) secretion in IMCD-K2 cells. We propose that these signaling pathways, and the crosstalk between them, may provide a concerted mechanism for enhancing urinary NaCl excretion under conditions of high dietary NaCl intake. PMID:24284792

Rajagopal, Madhumitha; Thomas, Sheela V; Kathpalia, Paru P; Chen, Yu; Pao, Alan C



The efflux of potassium, sodium, chloride, calcium and sulphate ions and of sorbitol and glycerol during the cardiac cycle in frog's ventricle  

PubMed Central

1. The exchanges of potassium and various other substances have been measured in beating frog's ventricles, using both superfused and distended preparations. In both preparations the high fluid flow rates used (1 ml./sec) cleared the ventricular cavity with a half-time (T) of about 130 msec. 2. Histological sections show that the modal strand radius in the relaxed or contracted distended ventricle is 175 ?, and in the relaxed and contracted superfused ventricle is 175 and 275 ? respectively. 3. In quiescent ventricles the resting potassium influx and efflux are approximately equal at about 16 p-mole/cm2.sec. This figure is computed from Niedergerke's (1963b) estimate of a cell size of 35 ? taken from electron-micrographs. If the older figure of 92 ? from single isolated cells is used (Skramlik, 1921) then the fluxes are about 44 p-mole/cm2.sec. To allow for some cell damage in these preparations a further increase in flux of about 30% may be necessary. 4. Contraction leads to a diminution of both potassium influx and efflux. Measurements made at 100 msec intervals throughout the cardiac cycle have demonstrated (a) that this decreased K efflux occurs at the same time as the mechanical twitch, and (b) that the size of the decrease is dependent on the external calcium concentration. Other experiments show that a similar decrease can be obtained by inducing a contracture at a constant membrane potential. It is concluded that the decreased K efflux during contraction is due to mechanical distortion of the tissue. This leads to a further slowing of the K diffusion and allows considerable reabsorption of K to occur into the cells. 5. Efflux analysis suggests that normal K diffusion in the extracellular space may be about 1/10 of that in free solution. If this is correct the true membrane fluxes may be 5 those measured. 6. Phasic efflux measurements of Na, Ca, K, Cl, SO4, sorbitol and erythritol show that a peak of efflux occurs just after the point of maximum rate of contraction of the ventricle. The peak efflux of K is least but all the other substances show similar patterns. In calcium-free solutions these phasic changes are absent. It is concluded that these effects are mechanical. 7. Net K and Na changes were measured in ventricles poisoned by ouabain. The computed net changes for quiescent ventricles were a gain of 28 p-mole/cm2.sec of Na and a loss of 53 p-mole/cm2.sec of K. On stimulation a further increase in Na uptake of 8 p-mole/cm2 occurred with no further loss of potassium. These results are computed for a cell diameter of 35 ?, for the larger diameter of 92 ? appropriate values of Na and K are 74 and 134 p-mole/cm2.sec respectively for quiescent ventricles and an extra Na uptake of 21 p-mole/cm2 per action potential. These results: (a) show that no large degree of single-file interaction occurs on the K movements, (b) are in agreement with the hypothesis that the membrane K fluxes are underestimated and (c) show that sufficient Na enters the cells per action potential to discharge a capacity of about 4 ?F/cm2. 8. A general conclusion reached in these experiments is that ion movements during the long cardiac action potential cannot easily be measured because of mechanical artifacts.

Lamb, J. F.; McGuigan, J. A. S.



Lipoxin A4 Stimulates Calcium-Activated Chloride Currents and Increases Airway Surface Liquid Height in Normal and Cystic Fibrosis Airway Epithelia  

PubMed Central

Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl? secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA4 is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA4 are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA4 produced a rapid and transient increase in intracellular Ca2+. We have investigated, the effect of LXA4 on Cl? secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA4 stimulated a rapid intracellular Ca2+ increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA4 stimulated whole-cell Cl? currents which were inhibited by NPPB (calcium-activated Cl? channel inhibitor), BAPTA-AM (chelator of intracellular Ca2+) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA4 increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA4 effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl? secretion. The LXA4 stimulation of intracellular Ca2+, whole-cell Cl? currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA4 in the stimulation of intracellular Ca2+ signalling leading to Ca2+-activated Cl? secretion and enhanced ASL height in non-CF and CF bronchial epithelia.

Al-Alawi, Mazen; Costello, Richard W.; McNally, Paul; Chiron, Raphael; Harvey, Brian J.; Urbach, Valerie



Surface charge density on silica in alkali and alkaline earth chloride electrolyte solutions  

NASA Astrophysics Data System (ADS)

The surface charge density of colloidal SiO 2 (Aerosil 380) was measured in alkali chloride (0.067 and 0.20 M LiCl, NaCl, and KCl) and alkaline earth chloride (0.067 M MgCl 2, CaCl 2, SrCl 2, BaCl 2) solutions. Measurements were conducted at 25C by potentiometric titrations using the constant ionic medium method in a CO 2-free system. The experimental design measured surface charge for solutions with constant ionic strength as well as constant cation concentration. Alkali chloride solutions promote negative surface charge density in the order LiCl < NaCl < KCl to give the "regular" lyotropic behavior previously reported. In contrast, the alkaline earth chloride solutions exhibit a reversed lyotropic trend with increasing crystallographic radius where increasing negative charge is promoted in the order BaCl 2 < SrCl 2 < CaCl 2 < MgCl 2. The origin of the opposing affinity trends is probed by testing the hypothesis that this reversal is rooted in the differing solvent structuring characteristics of the IA and IIA cations at the silica-water interface. This idea arises from earlier postulations that solvent structuring effects increase entropy through solvent disordering and these gains must be much greater than the small, positive enthalpy associated with electrostatic interactions. By correlating measured charge density with a proxy for the solvent-structuring ability of cations, this study shows that silica surface charge density is maximized by those electrolytes that have the strongest effects on solvent structuring. We suggest that for a given solid material, solvation entropy has a role in determining the ionic specificity of electrostatic interactions and reiterate the idea that the concept of lyotropy is rooted in the solvent-structuring ability of cations at the interface.

Dove, Patricia M.; Craven, Colin M.



Corrosion Resistances of Iron-Based Amorphous Metals with Yttrium and Tungsten Additions in Hot Calcium Chloride Brine & Natural Seawater: Fe48Mo14CR15Y2C15B6 and Variants  

SciTech Connect

The passive film stability of several Fe-based amorphous metal formulations have been found to be comparable to that of stainless steels and Ni-based Alloy C-22 (UNS No. N06022), based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. Electrochemical studies of the passive film stability of SAM1651 are reported here. Chromium (Cr), molybdenum (Mo) and tungsten (W) provide corrosion resistance; boron (B) enables glass formation; and rare earths such as yttrium (Y) lower critical cooling rate (CCR). Yttrium-containing SAM1651, also known as SAM7 (Fe{sub 48.0}Cr{sub 15.0}Mo{sub 14.0}B{sub 6.0}C{sub 15.0}Y{sub 2.0}), has a critical cooling rate (CCR) of approximately 80 Kelvin per second, while yttrium-free SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) has a higher critical cooling rate of approximately 600 Kelvin per second. SAM1651's low CCR enables it to be rendered as a completely amorphous material in practical materials processes. While the yttrium enables a low CCR to be achieved, it makes the material relatively difficult to atomize, due to increases in melt viscosity. Consequently, the powders have irregular shape, which makes pneumatic conveyance during thermal spray deposition difficult. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer or inhibitor. SAM1651 may also experience crevice corrosion under sufficiently harsh conditions. Both Alloy C-22 and Type 316L stainless lose their resistance to corrosion during thermal spraying, due to the formation of deleterious intermetallic phases which depletes the matrix of key alloy elements, whereas SAM1651 can be applied as coatings with the same corrosion resistance as a fully-dense completely amorphous melt-spun ribbon, provided that its amorphous nature is preserved during thermal spraying. Materials synthesis and characterization is discussed. Data showing the corrosion resistance of SAM1651 in hot concentrated calcium chloride, as well as natural seawater are presented, and compared to a number of reference materials.

Farmer, J; Haslam, J; Day, S; Lian, T; Saw, C; Hailey, P; Choi, J; Yang, N; Blue, C; Peter, W; Payer, J; Perepezko, J; Hildal, K; Branagan, D J; Beardsley, M B; Aprigliano, L



The influence of magnetism on precipitation of calcium phosphate  

NASA Astrophysics Data System (ADS)

The precipitation of calcium phosphate upon rapid mixing of solutions of CaCl 2 and KH 2PO 4-K 2HPO 4 was followed by pH and other quantitative measurements and the examination of the precipitate in the polarizing microscope. The experiments were carried out at 25C in the presence and absence of a static magnetic field of 0.27 T. It was found that the magnetic field increased dissolution of metastable precursor phases and increased nucleation of more stable phases. This was a general tendency for the transformation sequence: ACP? brushite ?OCP?HAP at initial pH?6.5 and total concentrations CCa= CP=25, 50 or 100 mM. Crystallization upon slow diffusion of ions from a solution of CaCl 2 into silica hydrogel containing dissolved KH 2PO 4-K 2HPO 4 was followed by recording the number and positions of appearing brushite crystals and Liesegang rings. The experiment was performed in the presence and absence of magnetic fields in the range 0.08-0.3 T and the following conditions: room temperature, initial pH of the gel between 5.5 and 6.8, and CCa= CP=50 mM. Magnetism increased nucleation of brushite in the experiments at low initial pH. The dependence on field strength was not significant, and no effect was found in experiments with high initial pH.

Skytte Srensen, Jens; Lundager Madsen, Hans E.



Arctigenin exhibits relaxation effect on bronchus by affecting transmembrane flow of calcium.  


Arctigenin, a lignan extract from Arctium lappa (L.), exhibits anti-inflammation, antioxidation, vasodilator effects, etc. However, the effects of arctigenin on bronchus relaxation are not well investigated. This study aimed to investigate how arctigenin regulates bronchus tone and calcium ion (Ca(2+)) flow. Trachea strips of guinea pigs were prepared for testing the relaxation effect of arctigenin to acetylcholine, histamine, KCl, and CaCl2, respectively. Furthermore, L-type calcium channel currents were detected by patch-clamp, and intracellular Ca(2+) concentration was detected by confocal microscopy. The results showed that arctigenin exhibited relaxation effect on tracheae to different constrictors, and this was related to decreasing cytoplasmic Ca(2+) concentration by inhibiting Ca(2+) influx partly through L-type calcium channel as well as promoting Ca(2+) efflux. In summary, this study provides new insight into the mechanisms by which arctigenin exhibits relaxation effect on bronchus and suggests its potential use for airway disease therapy. PMID:24114345

Zhao, Zhenying; Yin, Yongqiang; Wang, Zengyong; Fang, Runping; Wu, Hong; Jiang, Min; Bai, Gang; Luo, Guo'an



Influence of calcium sources on microbially induced calcium carbonate precipitation by Bacillus sp. CR2.  


Stimulation of microbially induced calcium carbonate precipitation (MICCP) is likely to be influenced by calcium sources. In order to study such influences, we performed MICCP using Bacillus sp. CR2 in nutrient broth containing urea, supplemented with different calcium sources (calcium chloride, calcium oxide, calcium acetate and calcium nitrate). The experiment lasted 7days, during which bacterial growth, urease activity, calcite production and pH were measured. Our results showed that calcium chloride is the better calcium source for MICCP process, since it provides higher urease activity and more calcite production. The influences of calcium sources on MICCP were further studied using Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. These analyses confirmed that the precipitate formed was CaCO3 and composed of predominantly calcite crystals with a little amount of aragonite and vaterite crystals. The maximum yield of calcite precipitation was achievable with calcium chloride followed by calcium nitrate as a calcium source. The results of present study may be applicable to media preparation during efficient MICCP process. PMID:24643454

Achal, Varenyam; Pan, Xiangliang



Preparation and Sustained-Release Property of Triblock Copolymer/Calcium Phosphate Nanocomposite as Nanocarrier for Hydrophobic Drug  

NASA Astrophysics Data System (ADS)

The P123/ACP nanocomposite with sizes less than 100 nm consisting of triblock copolymer P123 and amorphous calcium phosphate (ACP) has been prepared by using an aqueous solution containing CaCl2, (NH4)3PO4, and P123 at room temperature. The P123/ACP nanocomposite is used as the nanocarrier for hydrophobic drug ibuprofen, based on the combined advantages of both amphiphilic block copolymer and calcium phosphate delivery system. The P123/ACP nanocomposite has a much higher ibuprofen loading capacity (148 mg/g) than the single-phase calcium phosphate nanostructures. The drug release percentage of the P123/ACP nanocomposite in simulated body fluid reaches about 100% in a period of 156 h, which is much slower than that of single-phase calcium phosphate nanostructures. It is expected that the P123/ACP nanocomposite is promising for the application in the controlled delivery of hydrophobic drugs.

Cao, Shao-Wen; Zhu, Ying-Jie; Wu, Jin; Wang, Ke-Wei; Tang, Qi-Li



Antibacterial and bioactive calcium titanate layers formed on Ti metal and its alloys.  


An antibacterial and bioactive titanium (Ti)-based material was developed for use as a bone substitute under load-bearing conditions. As previously reported, Ti metal was successively subjected to NaOH, CaCl2, heat, and water treatments to form a calcium-deficient calcium titanate layer on its surface. When placed in a simulated body fluid (SBF), this bioactive Ti formed an apatite layer on its surface and tightly bonded to bones in the body. To address concerns regarding deep infection during orthopedic surgery, Ag(+) ions were incorporated on the surface of this bioactive Ti metal to impart antibacterial properties. Ti metal was first soaked in a 5M NaOH solution to form a 1?m-thick sodium hydrogen titanate layer on the surface and then in a 100mM CaCl2 solution to form a calcium hydrogen titanate layer via replacement of the Na(+) ions with Ca(2+) ions. The Ti material was subsequently heated at 600C for 1h to transform the calcium hydrogen titanate into calcium titanate. This heat-treated titanium metal was then soaked in 0.01-10mM AgNO3 solutions at 80C for 24h. As a result, 0.1-0.82at.% Ag(+) ions and a small amount of H3O(+) ions were incorporated into the surface calcium titanate layers. The resultant products formed apatite on their surface in an SBF, released 0.35-3.24ppm Ag(+) ion into the fetal bovine serum within 24h, and exhibited a strong antibacterial effect against Staphylococcus aureus. These results suggest that the present Ti metals should exhibit strong antibacterial properties in the living body in addition to tightly bonding to the surrounding bone through the apatite layer that forms on their surfaces in the body. PMID:24682896

Kizuki, Takashi; Matsushita, Tomiharu; Kokubo, Tadashi



Modulation of calcification of vascular smooth muscle cells in culture by calcium antagonists, statins, and their combination  

Microsoft Academic Search

Background Vascular calcification is an organized process in which vascular smooth muscle cells (VSMCs) are implicated primarily. The\\u000a purpose of the present study was to assess the effects of calcium antagonists and statins on VSMC calcification invitro.\\u000a Methods VSMC calcification was stimulated by incubation in growth medium supplemented with 10mmol\\/l ?-glycerophosphate, 8mmol\\/l\\u000a CaCl2, 10mmol\\/l sodium pyruvate, 1?mol\\/l insulin, 50?g\\/ml ascorbic

Astrid Trion; Cindy Schutte-Bart; Wilhelmina H. Bax; J. Wouter Jukema; Arnoud van der Laarse



21 CFR 184.1193 - Calcium chloride.  

Code of Federal Regulations, 2013 CFR

...jellies as defined in § 170.3(n)(28) of this chapter; 0.25 percent for meat products as defined in § 170.3(n)(29) of this chapter; 2.0 percent for plant protein products as defined in § 170.3(n)(33) of this chapter;...



Advanced calcium thionyl chloride high power battery  

Microsoft Academic Search

In this phase we have demonstrated that an improved c-size Ca\\/TC A type cell can deliver at RT up to 5.5 Ah at low rates and 4.4 Ah at 0.9A rate. It has 10 to 80 percent more capacity than have commercial Li-TC and Li-SO2 wound C-size cells. The improved Ca-TC cell lost almost no capacity after 4 to 5

Emanuel Peled



Effects of minerals on sporulation and heat resistance of Clostridium sporogenes  

Microsoft Academic Search

In this study, various mineral supplements, such as chloride salts (CaCl2, MgCl2, MnCl2, FeCl2 and KCl) supplying cations and calcium salts (CaCl2, CaCO3, CaSO4, Ca(OH)2 and CaHPO4) supplying anions, were tested if they could stimulate the sporulation of Clostridium sporogenes, a surrogate microorganism for C. botulinum. Of the cations tested, the addition of CaCl2 showed a slightly, but not significantly,

Jae-Hyung Mah; Dong-Hyun Kang; Juming Tang



Effects of mineral salts on the growth, sporulation and virulence of Esteya vermicola, an endoparasitic fungus of the pinewood nematode, Bursaphelenchus xylophilus  

Microsoft Academic Search

Esteya vermicola, an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against nematodes. In this study, various mineral supplements, such as chloride salts (KCl, CaCl2, MgCl2, FeCl2 and FeCl3) and calcium salts (CaCl2, CaCO3 and CaSO4) were evaluated for their ability to enhance the growth, sporulation and virulence of E. vermicola. Of the cations tested, CaCl2

Zhen Wang; Chunyan Wang; Min Liu; Yongan Zhang; Jianjie Xue; Yunbo Wang; Zheng Li; Jingang Hou; Jingjie Li; Changkeun Sung



Reversible loss of gravitropic sensitivity in maize roots after tip application of calcium chelators  

NASA Technical Reports Server (NTRS)

The application of calcium chelating agents (EDTA or EGTA) to the tips of maize roots caused a loss of gravitropic sensitivity. When the chelator was replaced with calcium chloride, gravitropic sensitivity was restored. Asymmetric application of calcium chloride near the tip of a vertical root caused curvature toward the calcium source. When the calcium was applied to the upper surface of the tip of a root oriented horizontally, the root curved upward even though control roots exhibited strong downward curvature. Application of calcium chloride to the tips of decapped roots, which are known to be gravitropically insensitive, did not restore gravitropic sensitivity. However, asymmetric application of calcium chloride near the tips of decapped roots caused curvature toward the calcium source. Calcium may play a key role in linking gravity detection to gravitropic curvature in roots.

Lee, J. S.; Mulkey, T. J.; Evans, M. L.



Calcium in Ciliary and Muscular Movement  

Microsoft Academic Search

IT is interesting to note that the unbalance obtained by reducing the calcium content of physiological solutions can to some extent be offset by the addition of small quantities of lipoids to the solution. Thus frog heart rendered hypodynamic, or even arrested, by Ringer solution less varying amounts of calcium chloride, can be made to beat normally again by adding

G. S. Carter; O. Gatty; J. H. Schulman; H. Walston



Poly Iron Chloride and Poly Aluminum Chloride.  

National Technical Information Service (NTIS)

The structures, basic chemistry, preparation procedures, and applications of poly iron chloride (PIC) and poly aluminum chloride (PAC) are presented. PIC and PAC are unconventional inorganic polymers known to be extremely effective for treatment of water ...

L. K. Wang



The relationship between calcium and increased sensitivity of rabbit aortae four hours after reserpine.  

PubMed Central

1 Four hours after reserpine, rabbit aortic strips were supersensitive to acetylcholine, isoprenaline and noradrenaline. The threshold concentration of the drugs necessary to induce a response was less and the maximum tension developed by the tissues was greater than in control strips. 2 Reserpine-treatment potentiated the contractile responses to CaCl2. 3 Reserpine-treatment resulted in an increase in calcium uptake and an increase in the slow component of 45Ca2+ efflux. 4 After resperine-treatment, the rate of relaxation from a potassium-induced contraction was decreased. 5 It is concluded that reserpine-induced supersensitivity is related to an enhanced ability of the tissue to retain and utilize calcium.

Carrier, O; Hester, R K



Influence of metallic chlorides on the formation of PCDD/Fs during low-temperature oxidation of carbon.  


Experimental study was conducted to clarify the formation behavior of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from carbonaceous materials through a de novo synthesis route. Samples were prepared by changing mixing method and composite state of metallic chloride in graphite powder in order to simulate the texture of "unburned carbonaceous particles", i.e., soot, formed in thermal processes. Reagents of KCl, CaCl2. 2H2O, FeCl3 x 6H2O, and CuCl2 x 2H2O were used as chlorine sources and were added to graphite powder with different methods. The composite state of metallic chloride was varied by preliminary treatments: hand-mixing, mixed-grinding using a high-intensity ball mill, and preheating at different temperatures between 500 and 1100 degrees C. In the de novo experiment, reaction temperature and oxygen concentration of flowed gas were set at 300 degrees C and 2.5 mol %, respectively. During the experiment, formation rates of CO and CO2 and the formed amounts of organic chlorine and PCDD/Fs were measured. The results show a reasonable relation between the amount of formed organic chlorine and oxidation rate of carbon, and the order of the activity of metallic chlorines was obtained as KCl < CaCl2 < FeCl3 < CuCl2. Furthermore, it was found that the effect of the composite state of metallic chloride on the formation of PCDD/Fs significantly depends on the kind of metal. The results will give useful information to examine the formation mechanism of PCDD/Fs from unburned carbon particles in thermal processes. PMID:12831028

Kuzuhara, S; Sato, H; Kasai, E; Nakamura, T



Mechanistic characterization of chloride interferences in electrothermal atomization systems  

USGS Publications Warehouse

A computer-controlled spectrometer with a photodiode array detector has been used for wavelength and temperature resolved characterization of the vapor produced by an electrothermal atomizer. The system has been used to study the chloride matrix interference on the atomic absorption spectrometric determination of manganese and copper. The suppression of manganese and copper atom populations by matrix chlorides such as those of calcium and magnesium is due to the gas-phase formation of an analyte chloride species followed by the diffusion of significant fractions of these species from the atom cell prior to completion of the atomization process. The analyte chloride species cannot be formed when matrix chlorides with metal-chloride bond dissociation energies above those of the analyte chlorides are the principal entitles present. The results indicate that multiple wavelength spectrometry used to obtain temperature-resolved spectra is a viable tool in the mechanistic characterization of interference effects observed with electrothermal atomization systems. ?? 1988 American Chemical Society.

Shekiro, Jr. , J. M.; Skogerboe, R. K.; Taylor, H. E.



Inhibition of calcium oxalate crystallization by glutamic acid: Different effects at low and high concentrations  

NASA Astrophysics Data System (ADS)

The effects of L-aspartic acid, alanine and L-glutamic acid on the crystallization of calcium oxalate were followed by two methods: measurements of the changes in calcium ion concentrations and determination of crystal size distribution in the calcium oxalate precipitate. The changes in calcium ion concentration were detected by a specific calcium electrode and are expressed as Discriminating Index (DI) values. Median size and number of crystals per milliliter were determined by Particle Data Counter. Glutamic acid in the range of 0-200 ppm was added to solutions of CaCl 2 which were subsequently mixed with solutions of Na 2C 2O 4 to yield CaC 2O 4 precipitation. At relatively high concentrations of glutamic acid, namely 20-200 ppm, the precipitation of calcium oxalate is retarded. However, at low concentrations, 2.5-20 ppm oxalate precipitation is enhanced. The two independent methods yield well-correlated results. Both L-aspartic acid and alanine did not affect the precipitation of calcium oxalate at similar experimental conditions.

Azoury, Reuven; Randolph, Alan D.; Drach, George W.; Perlberg, Saul; Garti, Nissim; Sarig, Sara



Hypotonicity activates a native chloride current in Xenopus oocytes.  


Xenopus oocytes are frequently utilized for in vivo expression of cellular proteins, especially ion channel proteins. A thorough understanding of the endogenous conductances and their regulation is paramount for proper characterization of expressed channel proteins. Here we detail a novel chloride current (ICl.swell) responsive to hypotonicity in Xenopus oocytes using the two-electrode voltage clamp technique. Reducing the extracellular osmolarity by 50% elicited a calcium-independent chloride current having an anion conductivity sequence identical with swelling-induced chloride currents observed in epithelial cells. The hypotonicity-activated current was blocked by chloride channel blockers, trivalent lanthanides, and nucleotides. G-protein, cAMP-PKA, and arachidonic acid signaling cascades were not involved in ICl.swell activation. ICl.swell is distinct from both stretch-activated nonselective cation channels and the calcium-activated chloride current in oocytes and may play a critical role in volume regulation in Xenopus oocytes. PMID:8189203

Ackerman, M J; Wickman, K D; Clapham, D E



Purification of aqueous plutonium chloride solutions via precipitation and washing.  

SciTech Connect

Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

Stroud, M. A. (Mary Ann); Salazar, R. R. (Richard R.); Abney, Kent David; Bluhm, E. A. (Elizabeth A.); Danis, J. A. (Janet A.)



Calcium tartrate gel.  


A method for preparation of a gel for chromatography has been developed. The adsorbent is calcium tartrate treated with potassium phosphate. By changing the temperature of synthesis (10-65 degrees C) and concentration of the salts (calcium chloride and sodium potassium tartrate) from 0.3 to 3.0 M, we have been able to prepare adsorbent crystals of definite sizes in the range 35-200 microns. In all cases, for synthesis of adsorbent, the Ca2+/K+Na+ ratio was greater than 1. After treatment of calcium tartrate crystals with 0.075-1.5 M potassium phosphate at 80-100 degrees C and pH 8.5-9.0, an appropriate chromatographic adsorbent was prepared. The chromatographic properties of calcium tartrate gel have been studied. The adsorbent permits flow rates of 25-150 ml/h, depending on the particle size. The capacity of calcium tartrate gel for binding BSA, RNA, and DNA was similar to that of Tiselius' hydroxyapatite (A. Tiselius, S. Hjerten, O. Levin (1956) Arch. Biochem. Biophys. 65, 132-155). The spheric shape of gel particles permits uniform and compact packing of adsorbent under the conditions of column chromatography. PMID:2757203

Akhrem, A A; Drozhdenyuk, A P



Recurring Slope Lineae (RSL) and Chloride Hydrates within Mars Subsurface  

NASA Astrophysics Data System (ADS)

RSL is an important phenomenon revealed by HiRISE-MRO observations on Mars (McEwen et al., 2011). The RSL form and grow on some equator-facing slopes during warm seasons on Mars when temperature (T in afternoon) is in the range of ~250-300K. We hypothesize that chloride hydrates may exist in some areas within the subsurface of southern hemisphere on Mars, and the deliquescence of these chloride hydrates at elevated temperature may have produced large quantity of brine that caused the RSL observed by HiRISE team. This hypothesis is based on three lines of reasoning: (1) chlorine (Cl) is found to be broadly distributed on Mars (GRS-ODY) and has been detected in the chemistry of every surface samples during all Mars surface exploration missions (Vikings, Pathfinder, Spirit, Opportunity, and Phoenix). In addition, the existence of chlorides in martian southern hemisphere was suggested by a set of THEMIS-ODY data analyses (Osterloo et al., 2008, 2010). In terrestrial saline playas, large amounts of chlorides invariably appears in the precipitates from salty brines (Zheng et al., 2009, Wang et al., 2009), although the precipitation sequence of chlorides on Mars might be different from that on Earth (Tosca et al., 2008, McLennan et al., 2012). (2) A subsurface layer when enriched with ice, or hydrous sulfates or chloride hydrates (all have high thermal inertia) and covered by a dry layer of surface soils (very low thermal inertia) will be able to maintain a lower Tmax and a much smaller delta-T that are not affected by the large temperature variations at Mars surface during diurnal and seasonal cycles (Mellon, 2004). (3) Chloride hydrates (such as MgCl2.12H2O, FeCl2.6H2O, CaCL2.6H2O, etc) would form from Cl-bearing brine at low T; they would be stable in a large T range (beyond room T in lab) and their deliquescence would occur abruptly at elevated temperatures (Baumgartner & Bakker 2009, and many others). We have started a systematic laboratory investigation on the thermodynamics and kinetics properties of chloride hydrates. The goals are to determine (1) the stability fields of Mg-, Fe2+-, Fe3+-, Ca-, Al-, Na-chloride hydrates in RH-T space, especially the phase boundaries of hydrates-deliquescence; (2) the rate of their dehydration, and especially the rate of their deliquescence as function of T, P, and PH2O; (3) the RH level that each chloride hydrate can maintain in an enclosure at T relevant to those within Mars subsurface. We will report the experimental results from (3), and will compare them with a similar set of data from hydrous sulfates (Mg, Fe, Ca, Al). The criticality of learning the property (3) is that the deliquescence of a hydrous salt at a T only occurs when RH is higher than a threshold. For example, deliquescence of ferricopiapite would happen when RH > 75% at 0C. If the environmental RH is lower, the dehydration of hydrous salt will go through solid-solid phase transition, instead of deliquescence, such that water would be released to the atmosphere and brine would not form. It is possible that deliquescence of both hydrous sulfates and chlorides (as well as the melting of Cl-enriched brines) contributed the RSL. Our working hypothesis favors chloride hydrates because dry chloride (after releasing water) in RSL would not be visible by Vis-NIR spectroscopy, which is consistent with the mission observations.

Lu, Y.; Wang, A.



On the growth of calcium tartrate tetrahydrate single crystals  

Microsoft Academic Search

Calcium tartrate single crystals were grown using silica gel as the growth medium. Calcium formate mixed with formic acid\\u000a was taken as the supernatant solution. It was observed that the nucleation density was reduced and the size of the crystals\\u000a was improved to a large extent compared to the conventional way of growing calcium tartrate crystals with calcium chloride.\\u000a The

X. Sahaya Shajan; C. Mahadevan



Copper, aluminum, iron and calcium inhibit human acetylcholinesterase in vitro.  


Acetylcholinesterase (AChE) is an important part of cholinergic nerves where it participates in termination of neurotransmission. AChE can be inhibited by e.g. some Alzheimer disease drugs, nerve agents, and secondary metabolites. In this work, metal salts aluminum chloride, calcium chloride, cupric chloride, ferric chloride, potassium chloride, magnesium chloride and sodium chloride were tested for their ability to inhibit AChE. Standard Ellman assay based on human recombinant AChE was done and inhibition was measured using Dixon plot. No inhibition was proved for sodium, potassium and magnesium ions. However, aluminum, cupric, ferric and calcium ions were able to inhibit AChE via noncompetitive mechanism of inhibition. Though the inhibition is much weaker when compared to e.g. drugs with noncompetitive mechanism of action, biological relevance of the findings can be anticipated. PMID:24473150

Pohanka, Miroslav



Growth Performance, Carcass Characteristics and Plasma Mineral Chemistry as Affected by Dietary Chloride and Chloride Salts Fed to Broiler Chickens Reared under Phase Feeding System  

PubMed Central

Requirements of dietary chloride (dCl) and chloride salts were determined by using 42 factorial arrangement under four phase feeding program. Four levels (0.31, 0.45, 0.59 and 0.73%) and two sources (NH4Cl and CaCl2) of the dCl were allocated to 1,472 chicks in eight dietary treatments in which each treatment was replicated four times with 46 birds per replicate. The four phase feeding program was comprised of four dietary phases: Prestarter (d 1 to 10), Starter (d 11 to 20), Grower (d 21 to 33) and Finisher (d 34 to 42); and diets were separately prepared for each phase. The cations, anions, pH, dissolved oxygen (DO), temperature, electrical conductivity (EC), total dissolved solids (TDS) and salinity were analyzed in drinking water and were not affected by dietary treatments. BW gain (BWG; p?0.009) and feed:gain (FG; p?0.03) were improved in CaCl2 supplemented diets during d 1 to 10. The maximum response of BWG and FG was observed at 0.38% and 0.42% dCl, respectively, for d 34 to 42. However, the level of dCl for BWG during d 21 to 33 (p?0.04) and d 34 to 42 (p?0.009) was optimized at 0.60% and 0.42%, respectively. The level of dCl for optimized feed intake (FI; p?0.006), FG (p?0.007) and litter moisture (LM; p?0.001) was observed at 0.60%, 0.38% and 0.73%, respectively, for d 1 to 42. Water intake (DWI) was not affected by increasing dCl supplementation (p>0.05); however, the ratio between DWI and FI (DWI:FI) was found highest at 0.73% dCl during d 1 to 10 (p?0.05) and d 21 to 33 (p?0.009). Except for d 34 to 42 (p?0.006), the increasing level of dCl did not result in a significant difference in mortality during any phase. Blood pH and glucose, and breast and thigh weights (percentage of dressed weight) were improved while dressing percentage (DP) and gastrointestinal health were exacerbated with NH4Cl as compared to CaCl2 supplemented diets (p?0.001). Higher plasma Na+ and HCO3? and lower Cl? and Ca++ were observed in NH4Cl supplemented diets (p?0.001). Increasing supplementation of dCl increased plasma Cl? (p?0.04; quadratically) and linearly reduced plasma K+ (p?0.001), Ca++ (p?0.003), HCO3? (p?0.001), and Na+ (p?0.001; quadratically). Consequently, higher requirements of dietary chloride are suggested for feed intake; nevertheless, lower levels of dietary chloride are sufficient to support optimal BWG and FG with increasing age. The NH4Cl supplemented diets ameliorate breast and thigh meat yield along with overall energy balance (glucose).

Mushtaq, M. M. H.; Pasha, T. N.; Akram, M.; Mushtaq, T.; Parvin, R.; Choi, H. C.; Hwangbo, J.; Kim, J. H.



Effect of acetate and propionate on calcium absorption from the rectum and distal colon of humans.  


To determine the effects of acetate and propionate on calcium absorption from the human distal colon and rectum, six healthy human subjects were given rectal infusions containing 50 mmol CaCl2/L on four separate occasions. Addition of 56.3 mmol acetate/L, 18.7 mmol propionate/L, or acetate and propionate together increased calcium disappearance (expressed as the change in the ratio of calcium to polyethylene glycol) from -5.5 +/- 1.4 to -22.6 +/- 2.8, -23.2 +/- 3.2, and -19.7 +/- 4.6, respectively; P < 0.05. To determine the effects of different acetate and propionate concentrations, six different subjects were studied further. The effects of 18.7 or 56.3 mmol acetate/L on calcium absorption were the same as those of 18.7 mmol propionate/L (-15.7 +/- 1.4), and less than those of 56.3 mmol propionate/L (-20.3 +/- 2.4, P < 0.05). We conclude that both acetate and propionate enhance calcium absorption from the human distal colon, but that propionate has a greater effect at higher concentrations. Further studies are needed to determine the mechanism of calcium absorption from the colon. PMID:8599322

Trinidad, T P; Wolever, T M; Thompson, L U



Delay of Membrane Lipid Degradation by Calcium Treatment during Cabbage Leaf Senescence 1  

PubMed Central

Cabbage leaf discs (Brassica oleracea L., Capitata group) were floated adaxial side up in 0, 0.05, or 0.25 m CaCl2 solutions at 15C for 14 d in the dark. To assess whether the delay of senescence by calcium treatment involved protection of membrane lipids, chlorophyll and protein content and the lipid composition of the membranes were determined during incubation. Chlorophyll and protein content decreased with time, in correlation with a reduction in the amount of phospholipids. The degree of unsaturation of phospholipids and free fatty acids decreased, whereas the ratio of sterol to phospholipid increased. The proportions of phospholipid classes did not change during senescence. The catabolism of phospholipids was delayed by 0.05 m calcium, but accelerated by 0.25 m, as compared to the untreated control. Based on the levels of the lipid intermediates, phospholipase D, phosphatidic acid phosphatase, lipolytic acyl hydrolase, and lipoxygenase appeared to be involved in the breakdown of phospholipids during senescence. Phospholipase D and phosphatidic acid phosphatase may be directly influenced by calcium. The calcium treatment apparently did not affect the activity of acyl hydrolase. Lipoxygenase, responsible for the peroxidation of the polyunsaturated fatty acids, was probably indirectly influenced by calcium. We conclude that the delay of senescence of cabbage leaf discs by calcium treatment involved protection of membrane lipids from degradation.

Cheour, Foued; Arul, Joseph; Makhlouf, Joseph; Willemot, Claude



Lactococcus lactis release from calcium alginate beads.  


Cell release during milk fermentation by Lactococcus lactis immobilized in calcium alginate beads was examined. Numbers of free cells in the milk gradually increased from 1 x 10(6) to 3 x 10(7) CFU/ml upon successive reutilization of the beads. Rinsing the beads between fermentations did not influence the numbers of free cells in the milk. Cell release was not affected by initial cell density within the beads or by alginate concentration, although higher acidification rates were achieved with increased cell loading. Coating alginate beads with poly-L-lysine (PLL) did not significantly reduce the release of cells during five consecutive fermentations. A double coating of PLL and alginate reduced cell release by a factor of approximately 50. However, acidification of milk with beads having the PLL-alginate coating was slower than that with uncoated beads. Immersing the beads in ethanol to kill cells on the periphery reduced cell release, but acidification activity was maintained. Dipping the beads in aluminum nitrate or a hot CaCl2 solution was not as effective as dipping them in ethanol. Ethanol treatment or heating of the beads appears to be a promising method for maintaining acidification activity while minimizing viable cell release due to loosely entrapped cells near the surface of the alginate beads. PMID:1622208

Champagne, C P; Gaudy, C; Poncelet, D; Neufeld, R J



Lactococcus lactis release from calcium alginate beads.  

PubMed Central

Cell release during milk fermentation by Lactococcus lactis immobilized in calcium alginate beads was examined. Numbers of free cells in the milk gradually increased from 1 x 10(6) to 3 x 10(7) CFU/ml upon successive reutilization of the beads. Rinsing the beads between fermentations did not influence the numbers of free cells in the milk. Cell release was not affected by initial cell density within the beads or by alginate concentration, although higher acidification rates were achieved with increased cell loading. Coating alginate beads with poly-L-lysine (PLL) did not significantly reduce the release of cells during five consecutive fermentations. A double coating of PLL and alginate reduced cell release by a factor of approximately 50. However, acidification of milk with beads having the PLL-alginate coating was slower than that with uncoated beads. Immersing the beads in ethanol to kill cells on the periphery reduced cell release, but acidification activity was maintained. Dipping the beads in aluminum nitrate or a hot CaCl2 solution was not as effective as dipping them in ethanol. Ethanol treatment or heating of the beads appears to be a promising method for maintaining acidification activity while minimizing viable cell release due to loosely entrapped cells near the surface of the alginate beads.

Champagne, C P; Gaudy, C; Poncelet, D; Neufeld, R J



Calcium - urine  


... from the kidneys, which causes calcium kidney stones Sarcoidosis Takiong too much calcium Too much production of ... metabolism. In: Goldman L, Ausiello D, eds. Cecil Medicine . 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap ...


Mutations in the putative calcium-binding domain of polyomavirus VP1 affect capsid assembly  

NASA Technical Reports Server (NTRS)

Calcium ions appear to play a major role in maintaining the structural integrity of the polyomavirus and are likely involved in the processes of viral uncoating and assembly. Previous studies demonstrated that a VP1 fragment extending from Pro-232 to Asp-364 has calcium-binding capabilities. This fragment contains an amino acid stretch from Asp-266 to Glu-277 which is quite similar in sequence to the amino acids that make up the calcium-binding EF hand structures found in many proteins. To assess the contribution of this domain to polyomavirus structural integrity, the effects of mutations in this region were examined by transfecting mutated viral DNA into susceptible cells. Immunofluorescence studies indicated that although viral protein synthesis occurred normally, infective viral progeny were not produced in cells transfected with polyomavirus genomes encoding either a VP1 molecule lacking amino acids Thr-262 through Gly-276 or a VP1 molecule containing a mutation of Asp-266 to Ala. VP1 molecules containing the deletion mutation were unable to bind 45Ca in an in vitro assay. Upon expression in Escherichia coli and purification by immunoaffinity chromatography, wild-type VP1 was isolated as pentameric, capsomere-like structures which could be induced to form capsid-like structures upon addition of CaCl2, consistent with previous studies. However, although VP1 containing the point mutation was isolated as pentamers which were indistinguishable from wild-type VP1 pentamers, addition of CaCl2 did not result in their assembly into capsid-like structures. Immunogold labeling and electron microscopy studies of transfected mammalian cells provided in vivo evidence that a mutation in this region affects the process of viral assembly.

Haynes, J. I. 2nd; Chang, D.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)



Investigation of factors influencing chloride extraction efficiency during electrochemical chloride extraction from reinforcing concrete  

NASA Astrophysics Data System (ADS)

Electrochemical chloride extraction (ECE) is an accelerated bridge restoration method similar to cathodic protection, but operates at higher current densities and utilizes a temporary installation. Both techniques prolong the life of a bridge by reducing the corrosion rate of the reinforcing bar when properly applied. ECE achieves this by moving chlorides away from the reinforcement and out of the concrete while simultaneously increasing the alkalinity of the electrolyte near the reinforcing steel. Despite the proven success, significant use of ECE has not resulted in part due to an incomplete understanding in the following areas: (1) An estimation of the additional service life that can be expected following treatment when the treated member is again subjected to chlorides; (2) The cause of the decrease in current flow and, therefore, chloride removal rate during treatment; (3) Influence of water-to-cement (w/c) ratio and cover depth on the time required for treatment. This dissertation covers the research that is connected to the last two areas listed above. To begin examining these issues, plain carbon steel reinforcing bars (rebar) were embedded in portland cement concrete slabs of varying water-to-cement (w/c) ratios and cover depths, and then exposed to chlorides. A fraction of these slabs had sodium chloride added as an admixture, with all of the slabs subjected to cyclical ponding with a saturated solution of sodium chloride. ECE was then used to remove the chlorides from these slabs while making electrical measurements in the different layers between the rebar (cathode) and the titanium mat (anode) to follow the progress of the ECE process. During this study, it was revealed that the resistance of the outer concrete surface layer increases during ECE, inevitably restricting current flow, while the resistance of the underlying concrete decreases or remains constant. During ECE treatment, a white residue formed on the surface of the concrete. Analyses of the residue revealed that it contains calcium carbonate, calcium chloride, and other yet unidentified minor components when calcium hydroxide was used as the electrolyte. The surface film can be completely removed mechanically or to some extent inhibited chemically, with both of these processes resulting in an increase in the efficiency of the electrochemical chloride extraction process. In addition, an obvious relationship between the cover depth, water-to-cement ratio, and chloride extraction efficiency does not exist, however, cover depth does influence the current density. The final phase of this study will be presented in a VTRC/FHWA final report. This report will include the results that are presented in this dissertation, in addition to the results from the ongoing research. It will also include an estimation of the additional service life that can be expected following treatment.

Sharp, Stephen R.


Calcium alginate microcapsules with spherical liquid cores templated by gelatin microparticles for mass production of multicellular spheroids.  


Multicellular spheroids are important in biomedical applications, such as drug research and regenerative medicine. We developed microcapsules from sodium alginate and gelatin for mass production of size-controlled spheroids with diameters <200 microm. The microcapsules were composed of calcium alginate gels with spherical liquid cores (diameter approximately 150 microm) for formation of spheroids. The spherical liquid cores were prepared by incubating calcium alginate microcapsules containing thermally gelled, cell-enclosing gelatin microparticles about 150 microm in diameter, at 37 degrees C. The gelatin microparticles were encapsulated within the microcapsules by dropping a sodium alginate solution containing suspended gelatin microparticles into 100 mM CaCl(2). The enclosed feline renal fibroblast cell line, CRFK, cells showed 93.8% viability immediately after encapsulation, then grew and completely filled the spherical cores. Multicellular spheroids were collected within 1 min by soaking microcapsules in a medium containing alginate lyase. PMID:20144915

Sakai, Shinji; Ito, Sho; Kawakami, Koei



Dehydration of Magnesium Chloride.  

National Technical Information Service (NTIS)

The patent application discloses a method for dehydrating magnesium chloride hydrates or brines by complexing with amine hydrochlorides. Magnesium chloride hydrate or brine is reacted to an amine hydrochloride to form a complex which is then heated to fir...

H. Dolezal



Chloride - urine test  


The urine chloride test measures the amount of chloride in urine. ... After you provide a urine sample, it is tested in the lab. If needed, the health care provider may ask you to collect your urine ...


Mercuric chloride poisoning  


Mercuric chloride is a very poisonous form of mercury. It is a type of mercury salt. There are different ... poisonings . This article discusses poisoning from swallowing mercuric chloride. This is for information only and not for ...


Interactions between chloride and sulfate or silica removals from wastewater using an advanced lime-aluminum softening process: equilibrium modeling.  


Interactions among chloride, sulfate, and silica removals from recycled industrial wastewater using an ultra-high lime with aluminum process (UHLA) were studied. An equilibrium model that is able to accurately predict the chemical behavior and interactions between chloride and sulfate or silica with UHLA at various initial conditions and chemical reagents was developed. X-ray diffraction (XRD) analysis was conducted to identify the precipitated solids formed in the UHLA process. Model predictions indicated that simultaneous removal of sulfate and chloride can be best described by the formation of a solid solution containing calcium chloroaluminate, calcium sulfoaluminate (ettringite), calcium monosulfate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate. However, simultaneous removal of silica and chloride can be best described by precipitation of calcium silicate and calcium aluminosilicate in addition to a solid solution containing calcium chloroaluminate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate. The XRD results indicated the presence of the same solids assumed by the equilibrium model. PMID:17571843

Abdel-Wahab, Ahmed; Batchelor, Bill



Determination of metallic iron in a mixture of lime, calcium sulphide and pyrrhotite.  


A method is described for the determination of metallic iron in a complex matrix consisting of calcium oxide, calcium sulphide, carbon and pyrrhotite. The procedure consists of leaching the sample with 5% ammonium chloride solution (10% sucrose solution in some cases) followed by treatment with mercury(II) chloride solution and titration with dichromate solution. PMID:18962353

Sastri, V S


Studies on the in vivo sensitivity of spindle microtubules to calcium ions and evidence for a vesicular calcium-sequestering system  

PubMed Central

I microinjected calcium ions into echinoderm eggs during mitosis to determine the calcium sensitivity of microtubules (Mts) in vivo. Spindle birefringence (BR), a measure of the number of aligned Mts in the spindle, is locally, rapidly, and reversibly abolished by small volumes of microinjected CaCl2 (1 mM). Rapid return of BR is followed by anaphase, and subsequent divisions are normal. Similar doses of MgCl2, BaCl2, KCl, NaCl, pH buffers, distilled water, or vegetable oil have no effect on spindle BR, whereas large doses of such agents sometimes cause slow, uniform loss in BR over the course of a minute or more. Of the ions tested, only Sr++ causes effects comparable to Ca++. Ca-EGTA buffers, containing greater than micromolar free Ca++, abolishes BR in a manner similar to millimolar concentrations of injected CaCl2. Caffeine, a potent uncoupler of the Ca++-pump/ATPase of sarcoplasmic reticulum, causes a local, transient depression in spindle BR in the injected region. Finally, injection of potassium oxalate results in the formation of small, highly BR crystals, presumably CA- oxalate, in Triton-sensitive compartments in the cytoplasm. Taken together, these findings demonstrate that spindle Mts are sensitive to levels of free Ca++ in the physiological range, provide evidence for the existence of a strong cytoplasmic Ca++-sequestering system, and support the notion that Mt assembly and disassembly in local regions of the spindle may be orchestrated by local changes in the cytoplasmic free Ca++ concentration during mitosis. An appendix offers the design of a new chamber for immobilizing echinoderm eggs for injection, a new method for determining the volume of the injected solution, and a description of the microinjection technique, which was designed, but never fully described, by Hiramoto (Y. Hiramoto, Exp. Cell. Res., 1962, 27:416-426.).



Crystallization of calcium sulfate dihydrate and calcium sulfite hemihydrate from synthetic flue gas desulfurization solutions: Final report  

SciTech Connect

The precipitation of calcium sulfate dihydrate (CaSO/sub 4/.2H/sub 2/O) and calcium sulfite hemihydrate (CaSO/sub 3/.1/2H/sub 2/O) from high, up to 240,000 mg/L, total dissolved solids (TDS) solutions was studied at 50/sup 0/C. The solutions were selected to cover a range of solution compositions of magnesium, calcium, sodium, chloride, and sulfate. Precipitation rates along with crystal habit and size changes were measured to determine the effects of these dissolved species as compared to dilute solution conditions. Calcium sulfate dihydrate (gypsum) precipitation rate was accelerated in the high TDS solutions, especially those containing chloride ion. Alternatively, calcium sulfite hemihydrate precipitation rate was found to be faster in high sulfate ion containing solutions. Sodium ion appears to produce gypsum crystals more columnar in habit while solutions containing high amounts of calcium produced very lamellar gypsum crystals. Solutions containing magnesium produced acicular gypsum crystals. Calcium sulfite hemihydrate solids precipitated from solutions containing high sulfate concentrations were rod shaped and globular as compared to the lamellar calcium sulfite hemihydrate crystals precipitated from high chloride and dilute solution liquors. Calcium sulfate-calcium sulfite solid solutions were characterized using infrared spectroscopy. Ion scavenging of Na, Mg, and Cl by gypsum and calcium sulfite solids precipitated from these high TDS solutions was also investigated. 10 refs., 21 figs., 13 tabs.

Trofe, T.W.; Fishman, V.A.; Meserole, F.B.



The kinetics of the reaction of hydrogen chloride with fresh and spent Ca-based desulfurization sorbents  

Microsoft Academic Search

The absorption of hydrogen chloride by spent desulfurization sorbents containing calcium carbonate, calcium oxide and calcium hydroxide was investigated. The experiments were carried out in a fixed-bed reactor in two temperature ranges: 423523 K for slaked lime and 673873 K for limestone and quicklime. The spent Ca-based sorbents can still react with hydrogen chloride, and after calcining and slaking they

Wuyin Wang; Zhicheng Ye; Ingemar Bjerle



Influence of calcium ions on the crystallization of sodium bicarbonate  

NASA Astrophysics Data System (ADS)

In industrial crystallization of sodium bicarbonate (sodium hydrogenocarbonate), the presence of calcium ions in solutions is unavoidable due to the production process. The understanding of the Ca 2+ role in NaHCO 3 crystallization would be helpful for improving the quality of the final products. The influence of calcium ions on NaHCO 3 crystallization was investigated in a 5-l mixed suspension mixed product removal crystallizer under controlled conditions. A density meter was used for continuous supersaturation monitoring. After a steady state had been reached, different CaCl 2 amounts were added at a constant flow rate. It was found that limited calcium ion levels in the system reduce drastically the nucleation frequency of NaHCO 3 and has a limited influence on crystal growth rate. The supersaturation measurements and other methods confirmed this phenomenon. The relationship between the Ca 2+ influence on NaHCO 3 crystallization, the calcium carbonate solubility and its metastable zone in concentrated NaHCO 3 solution was established. In fact, Ca 2+ has a maximum effect on NaHCO 3 crystallization kinetics when the saturation of calcium carbonate in NaHCO 3 solution has been reached, and the effect is constant in the metastable zone. The excess of Ca 2+ precipitates in NaHCO 3 solution as CaCO 3, as observed by energy dispersive X-ray and X-ray diffraction. This explained why an increasing Ca 2+ concentration in the solution has a limited influence on NaHCO 3 crystal size distribution and habit, but decreases the crystal purity. It is also confirmed that an impurity as Ca 2+ has no influence on the equilibrium NaHCO 3-Na 2CO 3.

Zhu, Yi; Demilie, Paul; Davoine, Perrine; Cartage, Thierry; Delplancke-Ogletree, Marie-Paule



Histochemical technique for the detection of chloride cells in fish.  


Chloride cells are responsible for ionic exchanges in the fish gill. These cells have been widely studied, considering its importance in vital functions of the gill, and because they proliferate when exposed to unfavorable environments. One of the main characteristic of these cells is an acidic cytoplasm, which has been used for identification through histochemical techniques with dyes such as Toluidine Blue and Hematoxylin and Eosin. However, these techniques can be problematic, since epithelial cells can, in certain situations, acquire acidic characteristics similar to those of chloride cells, thus staining in a similar way. Among other functions, chloride cells play a role in calcium uptake from the environment, and therefore have a high concentration of this element. Based on this information, this study aims at developing a specific protocol for the identification of chloride cells. With this purpose, the Von Kossa method specific for calcium was used combined with Hematoxylin counterstaining. Chloride cells had cytoplasm slightly stained with Hematoxylin and the presence of dark stained granules dispersed in the cytoplasm resulted from the Von Kossa reaction due to the calcium present in these cells. This was not found in any other gill cell. Thus, the technique used in this study was specific and efficient to identify chloride cells in fish gills. PMID:19674911

Pereira, Bruno Fiorelini; Caetano, Flvio Henrique



Effects of calcium concentration, acetate, and propionate on calcium absorption in the human distal colon.  


Previous studies have shown that the short-chain fatty acids acetate (Ac) and propionate (Pr) enhance the absorption of calcium (Ca) in the rectum and distal colon of humans, with Pr being more effective than Ac. To investigate the effect of Ac and Pr on the kinetics of Ca absorption from the human rectum and distal colon, six healthy subjects were studied. Solutions containing various concentrations of CaCl2.H2O with 56.3 mmol/L Ac, Pr, or NaCl were rectally infused to each subject. Rectal fluid was sampled at the end of the infusion (0 min), and 30 min later colonic contents were collected. Ca absorption for all treatments increased linearly with Ca concentration. For Ca + NaCl, the slope of regression line was 62 mumol.mmol-1.L Ca. With Ac + Ca, the slope of Ca absorption increased significantly to 113 mumol.mmol-1.L Ca, and with Pr + Ca, the slope increased to 159 mumol.mmol-1.L (P = 0.043 versus Ac + Ca) Ac and Pr absorption were increased by Ca. The data suggest that, over a physiologic range of Ca concentration, in the absence or presence of Ac and Pr, Ca is absorbed in the human rectum and distal colon by a non-saturable diffusion process, and that Ca absorption is enhanced by Ac and Pr. The data also suggest that both Ac and Pr absorption is stimulated by Ca. PMID:10422081

Trinidad, T P; Wolever, T M; Thompson, L U



Study on Immobilization Activated Sludge by Polyvinyl Alcohol-sodium Alginate - Calcium Nitrate in Domestic Sewage Treatment  

Microsoft Academic Search

Preparation conditions of immobilization activated sludge were studied with polyvinyl alcohol-sodium alginate as carrier and calcium nitrate as cross linking agent. Physical properties and removal effect of immobilization activated sludge were also investigated, where cross linking agent was boric acid, calcium chloride, calcium nitrate, respectively. The effect of sewage treatment was compared with activated sludge cross optimum linker calcium nitrate

Nie Qian; Jian Peichao; Liu Zhibin; Gu Fang



ClC chloride channels  

PubMed Central

Chloride-conducting ion channels of the ClC family are emerging as critical contributors to a host of biological processes. These polytopic membrane proteins form aqueous pathways through which anions are selectively allowed to pass down their concentration gradients. The ClCs are found in nearly all organisms, with members in every mammalian tissue, yet relatively little is known about their mechanism or regulation. It is clear, however, that they are fundamentally different in molecular construction and mechanism from the well-known potassium-, sodium-, and calcium-selective channels. The medical importance of ClC channels - four inherited diseases have been blamed on familial ClC dysfunction to date - highlights their diverse physiological functions and provides strong motivation for further study.

Mindell, Joe; Maduke, Merritt



Prediction of Incompatibility of Ceftriaxone Sodium with Calcium Ions Using the Ionic Product  

Microsoft Academic Search

The purpose of this study was to evaluate the incompatibility of ceftriaxone sodium with calcium-containing products using the ionic product of precipitation, and the measurement of insoluble microparticles using a light obscura- tion particle counter. Appropriate volumes of 2% (w\\/v) calcium chloride solution were added to 0.4? 2m g\\/ml ceftriaxone isotonic sodium chloride solution, to make solutions with anal calcium




Determination of Zinc Phytoavailability in Soil by Diffusive Gradients in Thin Films  

Microsoft Academic Search

Assessment of zinc (Zn) phytoavailability by the newly developed technique of diffusive gradients in thin films (DGT) has started gaining more importance because of some advantages over routine soil extractants. A greenhouse study was conducted to determine Zn phytotoxicity thresholds and the phytoavailability of Zn to sorghum sudan (Sorghum vulgare var. sudanese) grass by DGT, compared with calcium chloride (CaCl2)

Osman Sonmez; Cengiz Kaya; Salih Aydemir



The effect of dietary supplementation with calcium salts on skeletal calcium in suckling rats.  


This study aimed at identifying a calcium compound which could serve as an effective and safe dietary supplement in suckling rats over the period of intense growth and development. The main objective was to assess the effect of additional calcium intake on skeletal calcium in suckling pups. Suckling Wistar rats were fed using a pipettor with one of the following calcium salts from day 6 to 14 after the birth: gluconate, hydrogenphosphate, carbonate (each suspended in cow's milk), or chloride (in demineralized water). Control rats received only cow's milk. Calcium in the carcass (body without organs and skin) was analysed by atomic absorption spectrometry. The only effective dietary supplement that produced no risk for the suckling pups' growth was calcium hydrogenphosphate in cow's milk in the total amount of 340 mg. That dose increased the daily calcium intake 3 to 4 times compared to non-supplemented controls, increasing carcass calcium content by about 16 per cent. Other calcium compounds were either inefficient (carbonate) or had adverse effects on pups' growth (chloride and gluconate). PMID:14679662

Varnai, Veda Marija; Sari?, Marija; Mokrovi?, Gordana; Piasek, Martina; Blanusa, Maja; Buljan Culej, Jasminka; Matek Sari?, Marijana; Kostial, Krista



A Proposed Mechanism for the Thermal Denaturation of a Recombinant Bacillus Halmapalus Alpha-amylase - the Effect of Calcium Ions  

NASA Technical Reports Server (NTRS)

The thermal stability of a recombinant alpha-amylase from Bacillus halmapalus alpha-amylase (BHA) has been investigated using circular dichroism spectroscopy (CD) and differential scanning calorimetry (DSC). This alpha-amylase is homologous to other Bacillus alpha-amylases where previous crystallographic studies have identified the existence of 3 calcium binding sites in the structure. Denaturation of BHA is irreversible with a Tm of approximately 89 C, and DSC thermograms can be described using a one-step irreversible model. A 5 C increase in T(sub m) in the presence of 10 fold excess CaCl2 was observed. However, a concomitant increase in the tendency to aggregate was also observed. The presence of 30-40 fold excess calcium chelator (EDTA or EGTA) results in a large destabilization of BHA corresponding to about 40 C lower T(sub m), as determined by both CD and DSC. Ten fold excess EGTA reveals complex DSC thermograms corresponding to both reversible and irreversible transitions, which possibly originate from different populations of BHA:calcium complexes. The observations in the present study have, in combination with structural information of homologous alpha-amylases, provided the basis for the proposal of a simple denaturation mechanism of BHA. The proposed mechanism describes the irreversible thermal denaturation of different BHA:calcium complexes and the calcium binding equilibrium involved. Furthermore, the model accounts for a temperature induced reversible structural change associated with calcium binding.

Nielsen, Anders D.; Pusey, Marc L.; Fuglsang, Claus C.; Westh, Peter



Arsenic removal by ferric chloride  

SciTech Connect

Bench-scale studies were conducted in model freshwater systems to investigate how various parameters affected arsenic removal during coagulation with ferric chloride and arsenic adsorption onto preformed hydrous ferric oxide. Parameters included arsenic oxidation state and initial concentration, coagulant dosage or adsorbent concentration, pH, and the presence of co-occurring inorganic solutes. Comparison of coagulation and adsorption experiments and of experimental results with predictions based on surface complexation modeling demonstrated that adsorption is an important (though not the sole) mechanism governing arsenic removal during coagulation. Under comparable conditions, better removal was observed with arsenic(V) [As(V)] than with arsenic(III) [As(III)] in both coagulation and adsorption experiments. Below neutral pH values, As(III) removal-adsorption was significantly decreased in the presence of sulfate, whereas only a slight decrease in As(V) removal-adsorption was observed. At high pH, removal-adsorption of As(V) was increased in the presence of calcium. Removal of As(V) during coagulation with ferric chloride is both more efficient and less sensitive than that of As(III) to variations in source water composition.

Hering, J.G.; Chen, P.Y.; Wilkie, J.A.; Elimelech, M. [Univ. of California, Los Angeles, CA (United States). Dept. of Civil and Environmental Engineering; Liang, S. [Metropolitan Water District of Southern California, La Verne, CA (United States)



Investigation on MSW fly ash treatment by reactive calcium aluminates and phases formed  

Microsoft Academic Search

In this study hydration reactions of MSW fly ash with an experimental C12A7 \\/ C3A -cement are investigated. The fly ash has high contents of soluble calcium sulphates, alkali chlorides and heavy metals. During the first hours the calcium aluminates react with the calcium sulphate to form ettringite. On condition that the amount of added cement is sufficient, after complete

S. Auer; H.-J. Kuzel; H. Pllmann; F. Sorrentino



Calcium dependence of rapid auxin action in maize roots  

NASA Technical Reports Server (NTRS)

We investigated the interaction of Ca2+ and auxin on root elongation in seedlings of Zea mays L. The seedlings were raised either in the presence of Ca2+ (high calcium; HC = imbibed and raised in 10 millimolar CaCl2), in the absence of additional Ca2+ (intermediate calcium; IC = imbibed and raised in distilled H2O, calcium supply from seed only), or without additional Ca2+ and subsequently depleting them of Ca2+ (low calcium; LC = imbibed and raised in distilled H2O and subsequently treated with 1 millimolar ethyleneglycol-bis-[beta-aminoethylether]-N,N,N',N'-tetraacetic acid [EGTA]). Exposure of roots of either HC or IC seedlings to auxin concentrations from 0.1 to 10 micromolar resulted in strong inhibition of elongation. In roots of LC seedlings, on the other hand, auxin concentrations as high as 10 micromolar caused only slight inhibition of elongation. Adding 0.5 millimolar Ca2+ to LC roots in the presence of IAA allowed normal expression of the inhibitory action of the hormone. Inhibition of elongation in IC roots by indoleacetic acid was reversible upon treatment of the roots with 1 millimolar EGTA. The inhibitory action of auxin could then be re-established by supplying 0.5 millimolar Ca2+. The data indicate that Ca2+ may be necessary to the growth-regulating action of auxin. The significance of this finding is discussed with respect to the potential role of Ca2+ as a second messenger of auxin action and the relevance of this model to recent evidence for gravi-induced redistribution of Ca2+ and its role in establishing gravitropic curvature.

Hasenstein, K. H.; Evans, M. L.



5-Hydroxytryptamine-induced calcium-channel gating in rainbow trout (Oncorhynchus mykiss) peripheral blood lymphocytes.  

PubMed Central

The present study was conducted on peripheral blood lympho-cytes of rainbow trout (Oncorhynchus mykiss) to assess the role of 5-hydroxytryptamine (5-HT; 'serotonin') in calcium signalling. 5-HT-induced increases in intracellular free calcium concentrations, [Ca2+]i, and its action was mediated by 5-HT receptor subtype 3 (5-HT3), but not by 5-HT receptor subtype 1A (5-HT1A) or subtype 2 (5-HT2) in these cells. In Ca2+-containing medium (1 mM CaCl2), 5-HT and 2-methyl-5-HT (5-HT3 receptor agonist) induced increases in [Ca2+]i, whereas in Ca2+-free medium (0 Ca2+, 1 mM EGTA), these two agents failed to evoke increases in [Ca2+]i in these cells, demonstrating that 5-HT mobilizes Ca2+ from the extracellular environment. Furthermore, 5-HT-induced increases in [Ca2+]i are not contributed to by the intracellular endoplasmic reticulum (ER) pool, as thapsigargin, an agent that recruits Ca2+ from ER stores, had additive effects on 5-HT-induced [Ca2+]i responses in fish peripheral lymphocytes. 5-HT-induced increases in [Ca2+]i were mediated by 5-HT3 receptors via gating the calcium through L-type, but not N-type, calcium channels in trout lymphocytes.

Ferriere, F; Khan, N A; Meyniel, J P; Deschaux, P



Calcium antagonistic activity of Bacopa monniera in guinea-pig trachea  

PubMed Central

Objective: To demonstrate the calcium antagonistic property of ethanol extract of Bacopa monniera in guinea-pig trachea. Materials and Methods: The dose response curves of CaCl2 (1 10-5 to 1 10-1 M) were constructed in the absence and presence of ethanol extract of Bacopa monniera (100, 500 and 700 ?g/ml) or nifedipine (1 10-6 M) in guinea-pig trachea in calcium free high K+-MOPS-PSS (3-(N-morpholino)-propanesulphonic acid physiological salt solution). The data was analyzed by ANOVA followed by least significant difference test or by Student's t test for unequal variance when appropriate. A probability of at least P < 0.05 was considered statistically significant. Results: The plant extract (500 and 700 ?g/ml) significantly (P < 0.05) depressed and shifted the calcium concentration-response curves (1 10-3- 1 10-1 M) to rightward similar to that of nifedipine. Conclusions: Bacopa monniera extract exhibited calcium channel blocking activity in guinea-pig tracheal smooth muscles that may rationalize its relaxant action on guinea-pig trachea and its traditional use in respiratory disorders.

Channa, Shabana; Dar, Ahsana



Effect of Postmortem Injection Time and Postinjection Aging Time on the Calcium-Activated Tenderization Process in Beef  

Microsoft Academic Search

The objectives of this study were to determine 1 ) the effectiveness of calcium chloride when injected later than 2 d postmortem, 2 ) the effect of extended postinjection aging time, and 3 ) the tenderness response curve in calcium chloride-treated beef. In Exp. 1, the longissimus thoracis et lumborum was injected on either d 2 or 14 postmortem with

T. L. Wheeler; M. Koohmaraie; S. D. Shackelford



Electrothermal vaporization on a tungsten filament for the determination of arsenic in chloride solutions by low-pressure helium ICP-MS.  


A combined method of electrothermal vaporization and low-pressure helium ICP-MS was developed for the determination of traces of arsenic in chloride solutions, because serious spectral interference occurred in conventional argon ICP-MS. On a tungsten filament was placed 5 microl of a sample and heated electrothermally to remove the solvent. The resulting residue on the filament was covered with a vaporization chamber, and after reducing the pressure to ca. 5 Torr, it was rapidly heated by discharging a high-capacity condenser (0.22 F). The vapor of arsenic was transferred to a helium plasma with a stream of carrier gas for the determination. The background was not observed at m/z of 75, which allowed the determination of arsenic at ng/ml levels in chloride solutions. Sodium chloride significantly enhanced the intensity of the arsenic signal, whereas other chlorides, including KCl, MgCl2, CaCl2 and NH4Cl, suppressed the analytical signals. This enhancement due to sodium ions seems to be a peculiar phenomenon to the helium ICP. The proposed method can be applied to direct determinations of as low as 0.9 ng/ml of arsenic in seawater. PMID:11993658

Hayashi, H; Tanaka, T; Hiraide, M



Phosphonium chloride for thermal storage  

NASA Technical Reports Server (NTRS)

Development of systems for storage of thermal energy is discussed. Application of phosphonium chloride for heat storage through reversible dissociation is described. Chemical, physical, and thermodynamic properties of phosphonium chloride are analyzed and dangers in using phosphonium chloride are explained.

Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.



Carcinogenicity of vinyl chloride and vinylidene chloride  

Microsoft Academic Search

Exposure of mice to 50, 250, or 1000 ppm of vinyl chloride (VC) in the air for 6 h\\/d, 5 d\\/wk, caused a high incidence of bronchioloalveolar adenoma, mammary gland tumors, and hemangiosarcoma. Mammary gland tumors occurred in the females and included ductular odenocarcinoma and squamous and anaplastic cell carcinomas with metastasis to the lung. Hemangiosarcoma occurred in the liver

C. C. Lee; J. C. Bhandari; J. M. Winston; W. B. House; R. L. Dixon; J. S. Woods



Minerals Yearbook 1991: Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

Calcium, is chemically very active and is found in a host of minerals that occur in nearly every geologic environment. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or anhydrite; calcium oxide and hydroxide as lime; calcium phosphate as...

M. M. Miller



Apatite-forming ability of Ti-15Zr-4Nb-4Ta alloy induced by calcium solution treatment.  


Ti-15Zr-4Nb-4Ta alloy free from cytotoxic elements shows high mechanical strength and high corrosion resistance. However, simple NaOH and heat treatments cannot induce its ability to form apatite in the body environment. In the present study, this alloy was found to exhibit high apatite-forming ability when it was treated with NaOH and CaCl(2) solutions, and then subjected to heat and hot water treatments to form calcium titanate, rutile, and anatase on its surface. Its high apatite-forming ability was maintained even in 95% relative humidity at 80 degrees C after 1 week. The surface layer of the treated alloy had scratch resistance high enough for handling hard surgical devices. Thus, the treated alloy is believed to be useful for orthopedic and dental implants. PMID:19842018

Yamaguchi, Seiji; Takadama, Hiroaki; Matsushita, Tomiharu; Nakamura, Takashi; Kokubo, Tadashi



Regulation of Chloride Channels by Protein Kinase C in Normal and Cystic Fibrosis Airway Epithelia  

NASA Astrophysics Data System (ADS)

Apical membrane chloride channels control chloride secretion by airway epithelial cells. Defective regulation of these channels is a prominent characteristic of cystic fibrosis. In normal intact cells, activation of protein kinase C (PKC) by phorbol ester either stimulated or inhibited chloride secretion, depending on the physiological status of the cell. In cell-free membrane patches, PKC also had a dual effect: at a high calcium concentration, PKC inactivated chloride channels; at a low calcium concentration, PKC activated chloride channels. In cystic fibrosis cells, PKC-dependent channel inactivation was normal, but activation was defective. Thus it appears that PKC phosphorylates and regulates two different sites on the channel or on an associated membrane protein, one of which is defective in cystic fibrosis.

Li, Ming; McCann, John D.; Anderson, Matthew P.; Clancy, John P.; Liedtke, Carole M.; Nairn, Angus C.; Greengard, Paul; Welsh, Michael J.



Conversion of sodium chloride to hydrogen chloride in the atmosphere  

Microsoft Academic Search

A reaction route is suggested, based on experimental results, for the conversion of sodium chloride particles to gaseous hydrogen chloride in the atmosphere. The first step is the hydrolysis of nitrogen dioxide (NO) to form nitric acid (HNO) vapor. The second step is either adsorption on the relatively dry sodium chloride and the fourth is desorption of the hydrogen chloride,

R. C. Robbins; R. D. Cadle; D. L. Eckhardt



[Congenital chloride diarrhea].  


Congenital chloride diarrhea (CCD) is a rare hereditary disease, with a prenatal onset, secondary to a deficit in the intestinal chloride transport. In the present study, we describe the clinical characteristics of three patients with congenital watery diarrhea, two of them females, aged between 9 and 14 months at the first visit. All patients presented perinatal antecedents of polyhydramnios and prematurity, watery stools since birth and growth failure. Metabolic alkalosis, hypokalemia and hypochloremia were found. Stool ionogram with elevated doses of chloride, exceeding both sodium and potassium, confirmed the diagnosis of CCD. Substitute treatment with sodium and potassium chloride was started with good results. CCD should be considered as a differential diagnosis to congenital watery diarrhea, since early diagnosis and appropriate treatment are mandatory for the normal development of the child, avoiding severe complications such as neurological sequelae and even death. PMID:16127986

Contreras, Mnica; Rocca, Ana; Benedetti, Laura; Kakisu, Hisae; Delgado, Sabrina; Ruiz, Jos Antonio



Hydrogen chloride test set  

NASA Technical Reports Server (NTRS)

Detector uses tertiary amine, which makes reaction fairly specific for relatively small highly polarized hydrogen chloride molecule. Reaction is monitored by any microbalance capable of measuring extremely small mass differences in real time.

Workman, G. L.



40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.  

Code of Federal Regulations, 2010 CFR

...dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section...dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator...vinyl chloride, and/or polyvinyl chloride plant shall comply with...



Composite phospholipid-calcium carbonate microparticles: influence of anionic phospholipids on the crystallization of calcium carbonate.  


The synthesis and characterization of calcium carbonate microparticles by reaction of calcium chloride and ammonium bicarbonate in the presence of negatively charged phospholipid mixtures of negative and zwitterionic phospholipids has been reported. Negatively charged phospholipids influence the crystal morphology of calcium carbonate and induce the formation of thermodynamically less stable veterite polymorph as opposed to calcite polymorph. The phospholipids are entrapped in the calcium carbonate microparticles during the crystallization process, with a uniform distribution of phospholipids in the interior of the microparticles. This phenomenon was exploited to encapsulate a model hydrophobic fluorophore, the tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) dichloride complex, to simulate encapsulation of hydrophobic drug molecules. Thermogravimetric analysis reveals that, in these microparticles, the calcium carbonate and the phospholipid exhibit strong interactions. PMID:16471842

Gopal, Krishna; Lu, Zonghuan; de Villiers, Melgardt M; Lvov, Yuri



Determination of cytoplasmic calcium concentration in Dryopteris spores: a developmentally non-disruptive technique for loading of the calcium indicator fura-2  

NASA Technical Reports Server (NTRS)

Germination of Dryopteris spores is mediated by the physiologically active, far-red-absorbing form of phytochrome, Pfr, and external Ca2+ is necessary for the transduction of the light signal. Because knowledge about the cytoplasmic calcium ion concentration, [Ca2+]i, is of great importance for understanding the role of calcium during signal transduction, this value was measured using fura-2 in fern spores undergoing the normal developmental progression into germination. Fura-2 was loaded into the spores by electroporation, which does not disrupt the normal process of germination. The intensity of the fluorescence emission of the loaded fura-2 was analysed by a microspectrophotometric assay of single spores, and successful loading could be obtained by the application of ten electrical pulses (field strength 7.5 kV cm-1, half-life (time constant) 230 microseconds). Fura-2 was alternately excited by light of wavelengths 355 and 385 nm through an inverted fluorescence microscope, and the emitted fura-2 fluorescence was collected by a silicon-intensified video camera. The cytoplasmic calcium ion concentration was calculated from the ratio of the camera output obtained for both wavelengths and displayed by a pseudo-color technique. Spores responded to changes of the extracellular Ca2+ concentration, and this observation is considered as evidence that fura-2 is loaded into the cytoplasm. The substitution of a low external [Ca2+] (1 mM ethyleneglycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA)) by 1 mM CaCl2 caused a fast increase of [Ca2+]i from approx. 50 nM to above 500 nM. In contrast, the subsequent substitution of CaCl2 by EGTA decreased [Ca2+]i again below 100 nM within 0.5 h. Furthermore, the application of ionomycin could initiate a change in [Ca2+]i according to the Ca2+ gradient established between the extracellular medium and cytoplasm. In spores sown on a Ca(2+) -free medium, [Ca2+]i, analysed in a buffer containing EGTA, was found to be around 50 nM during the first days of cultivation, independent of the irradiation protocol. However, if spores were grown in darkness on a Ca(2+) -containing medium and analysed in EGTA, [Ca2+]i was significantly higher (> or = 500 nM). In red-light-irradiated spores, [Ca2+]i was found to decrease with increasing time after irradiation, and was determined to be less than 100 nM when analysis was done 44 h after germination was initiated by the light treatment.

Scheuerlein, R.; Schmidt, K.; Poenie, M.; Roux, S. J.



An Apical-Membrane Chloride Channel in Human Tracheal Epithelium  

NASA Astrophysics Data System (ADS)

The mechanism of chloride transport by airway epithelia has been of substantial interest because airway and sweat gland-duct epithelia are chloride-impermeable in cystic fibrosis. The decreased chloride permeability prevents normal secretion by the airway epithelium, thereby interfering with mucociliary clearance and contributing to the morbidity and mortality of the disease. Because chloride secretion depends on and is regulated by chloride conductance in the apical cell membrane, the patch-clamp technique was used to directly examine single-channel currents in primary cultures of human tracheal epithelium. The cells contained an anion-selective channel that was not strongly voltage-gated or regulated by calcium in cell-free patches. The channel was also blocked by analogs of carboxylic acid that decrease apical chloride conductance in intact epithelia. When attached to the cell, the channel was activated by isoproterenol, although the channel was also observed to open spontaneously. However, in some cases, the channel was only observed after the patch was excised from the cell. These results suggest that this channel is responsible for the apical chloride conductance in airway epithelia.

Welsh, Michael J.



Project Calcium  

SciTech Connect

Fouling problems in utility boilers have been classified into two principal types: high-temperature and low-temperature fouling. A multiclient-sponsored program was initiated at the Energy and Environmental Research Center (EERC) to better understand the causes of low-temperature fouling when burning high-calcium western US coals. The goals of Project Calcium were to define the low-temperature deposition problem, identify the calcium-based components that are responsible for the formation of the deposits, develop ways to predict their formation, and identify possible methods to mitigate the formation of these deposits. To achieve the goals of Project Calcium, detailed sampling of utility boilers and laboratory-scale studies coupled with state-of-the-art methods to determine the inorganic components in coals and coal ash-derived materials were conducted. Boiler Sampling was also performed. The work involved sampling coal, entrained ash, deposits and slags from five full-scale utility boilers combined with detailed advanced characterization of the materials. The results of this work aided in identifying the key phenomena to focus the laboratory studies and in model verification. Field testing was conducted at three utilities.

Hurley, J.P.; Benson, S.A.; Erickson, T.A.; Allan, S.E.; Bieber, J.



Calcium Causes a Conformational Change in Lamin A Tail Domain that Promotes Farnesyl-Mediated Membrane Association  

PubMed Central

Lamin proteins contribute to nuclear structure and function, primarily at the inner nuclear membrane. The posttranslational processing pathway of lamin A includes farnesylation of the C-terminus, likely to increase membrane association, and subsequent proteolytic cleavage of the C-terminus. Hutchinson Gilford progeria syndrome is a premature aging disorder wherein a mutant version of lamin A, ?50 lamin A, retains its farnesylation. We report here that membrane association of farnesylated ?50 lamin A tail domains requires calcium. Experimental evidence and molecular dynamics simulations collectively suggest that the farnesyl group is sequestered within a hydrophobic region in the tail domain in the absence of calcium. Calcium binds to the tail domain with an affinity KD ? 250 ?M where it alters the structure of the Ig-fold and increases the solvent accessibility of the C-terminus. In 2mM CaCl2, the affinity of the farnesylated protein to a synthetic membrane is KD ? 2 ?M, as measured with surface plasmon resonance, but showed a combination of aggregation and binding. Membrane binding in the absence of calcium could not be detected. We suggest that a conformational change induced in ?50 lamin A with divalent cations plays a regulatory role in the posttranslational processing of lamin A, which may be important in disease pathogenesis.

Kalinowski, Agnieszka; Qin, Zhao; Coffey, Kelli; Kodali, Ravi; Buehler, Markus J.; Losche, Mathias; Dahl, Kris Noel



Zinc Sorption in Sandy Soils from Central Vietnam as a Function of Soil Characteristics  

Microsoft Academic Search

Zinc (Zn) sorption curves were established for 11 cultivated sandy soils from central Vietnam. Soil samples (10 g) were equilibrated with 5 mM calcium chloride (CaCl2) solutions (50 mL) at five zinc chloride (ZnCl2) concentrations (0 to 80 mg Zn L). The experimental sorption data were fitted with the Freundlich equation. The amounts of Zn sorbed by soil (QZn) at

Gaetan Verriest; Elonore Couder; Hoa Hoang Thi Thai; Stephen Bythell; Anne Iserentant; Claudine Givron; Joseph E. Dufey



Comparative evaluation of hydro-, chemo- , and hormonal-priming methods for imparting salt and PEG stress tolerance in Indian mustard ( Brassica juncea L.)  

Microsoft Academic Search

The present study was aimed to evaluate the effect of different seed priming methods to enhance the sodium chloride (NaCl)\\u000a and polyethylene glycol-8000 (PEG-8000) stress tolerance in Indian mustard (Brassica juncea L.). Seeds subjected to different priming treatments such as water (hydro-priming), calcium chloride (CaCl2) (chemo-priming), and abscisic acid (ABA) (hormonal-priming) showed increased rate of germination as compared to non-primed

Ashish Kumar Srivastava; Vinayak H. Lokhande; Vikas Y. Patade; Penna Suprasanna; Rinaldi Sjahril; Stanislaus Francis DSouza



Preparation of coagulant from red mud and semi-product of polyaluminum chloride for removal of phosphate from water  

Microsoft Academic Search

Traditionally, calcium aluminate, caustic soda, lime or aluminum slag was employed as alkali for basicity adjustment in the production of polyaluminum chloride (PACl). In this work, red mud (RM), a highly alkaline waste from alumina industry, was utilized instead of the traditional alkali. A composite coagulant (RMPACl) was prepared from RM and the semi-product of polyaluminum chloride (ACl). Important factors

Fan Ni; Xianjia Peng; Ying Zhao; Jinsong He; Yiran Li; Zhaokun Luan



Chloride removal from vitrification offgas  

SciTech Connect

This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations.

Slaathaug, E.J. [Westinghouse Hanford Co., Richland, WA (United States)



Molecular Structure of Barium Chloride  

NSDL National Science Digital Library

Barium Chloride was the byproduct of the discovery of radium by Madame Curie. When refining radium, the final separation resulted in barium chloride and radium chloride. Electrophoresis of barium chloride produces small-scale amounts of barium atom. This can be used for obtaining barium for commercial uses. Applications of barium chloride include stimulating the heart and other muscles for medicinal purposes, and also for softening water. Other uses of barium chloride include the manufacturing of barium salts, as pesticide, pigments, boiler detergent, in purifying sugar, as mordant in dyeing and printing textiles, and in the manufacture of caustic soda, polymers, and stabilizers.



Impairment of ?1-adrenoceptor-mediated calcium influx in contralateral carotids following balloon injury: beneficial effect of superoxide anions.  


There are many evidences indicating a compensatory mechanism in contralateral carotids following balloon injury. Previously it was observed ?1-adrenoceptor-mediated hyper-reactivity and impairment of calcium influx in contralateral carotids 4 days after injury. At a later stage, ?1-adrenoceptor-mediated contraction is similar to the control and we hypothesized that downstream signaling was normal. In the present study, we aimed to evaluate ?1-adrenoceptor-mediated calcium influx in contralateral carotids 15 days after balloon injury. Concentration-response curves for CaCl2 in presence of the ?1-adrenoceptor agonist (phenylephrine), measurement of the intracellular calcium transient and the levels of reactive oxygen species using fluorescent dyes were performed in control and contralateral carotids. Phenylephrine-induced intracellular calcium mobilization in contralateral carotids was not altered, while phenylephrine-induced calcium influx was reduced in the contralateral artery. Nitric oxide synthase inhibitors, L-NAME or L-NNA, restored this response, but nitrite and nitrate levels were decreased in contralateral carotids. Additionally, a rise in oxygen free radicals was observed in contralateral carotids. Furthermore, Tiron, a superoxide anion scavenger, restored ?1-adrenoceptor-mediated calcium influx in contralateral carotids to the control level. Similar results were observed with the selective potassium channels blockers 4-aminopyridine and charybdotoxin. In conclusion, data showed that balloon catheter injury resulted in increased superoxide anions levels, activation of potassium channels (Kv and BKCa), inhibition of calcium channels (Cav) and preservation of ?1-adrenoceptor-mediated contraction at a later stage after injury. PMID:24216248

Pereira, Aline C; Olivon, Vania C; Pernomian, Larissa; de Oliveira, Ana M



Chloride chemical form in various types of fly ash  

SciTech Connect

Chloride content is a critical problem for the reuse of fly ash as a raw material in cement, and the method used by recyclers to reduce the fly ash chloride content depends on the chemical form of the chlorides. However, limited information is available on the quantitative distribution of chlorides and the identity of some chlorides such as Friedel's salt. We examined chloride forms and percentages using X-ray absorption near edge structure and X-ray diffraction analyses, as well as corresponding washing experiments. Approximately 15% of the chlorine in raw fly ash was estimated to be in the form of NaCl, 10% in KCl, 50% in CaCl{sub 2}, and the remainder in the form of Friedel's salt. Fly ash collected in a bag filter with the injection of calcium hydroxide for acid gas removal (CaFA) contained 35% chlorine as NaCl, 11% as KCl, 37% as CaCl{sub 2}, 13% as Friedel's salt, and the remaining 4% as CaClOH. In fly ash collected in a bag filter with the injection of sodium bicarbonate for acid gas removal (NaFA), approximately 79% of chlorine was in NaCl, 12% was in KCl, and 9% was in Friedel's salt. 25 refs., 4 figs., 4 tabs.

Fenfen Zhu; Masaki Takaoka; Kenji Shiota; Kazuyuki Oshita; Yoshinori Kitajima [Kyoto University, Kyoto (Japan). Department of Urban and Environmental Engineering




PubMed Central

Giant axons from the squid, Loligo pealei, were fixed in glutaraldehyde and postfixed in osmium tetroxide. Calcium chloride (5 mM/liter) was added to all aqueous solutions used for tissue processing. Electron-opaque deposits were found along the axonal plasma membranes, within mitochondria, and along the basal plasma membranes of Schwann cells. X-ray microprobe analysis (EMMA-4) yielded signals for calcium and phosphorus when deposits were probed, whereas these elements were not detected in the axoplasm.

Oschman, J. L.; Hall, T. A.; Peters, P. D.; Wall, B. J.



Characterization of condensed phase species produced during the thermal treatment of metal chlorides on a graphite platform using surface analysis techniques  

NASA Astrophysics Data System (ADS)

The identification and distribution of condensed phase species produced on a graphite platform at temperatures between 200 and 2000 C was studied using data obtained by scanning electron microscopy (SEM), energy dispersive (ED) X-ray spectrometry and Raman microanalysis. The first general conclusion is that there is no unique path in the thermal transformation of the metal chlorides tested, even for a particular metal chloride. Sodium, potassium and calcium chlorides showed similar vaporization characteristics, evolving mainly as monochlorides, while magnesium, beryllium and aluminium mainly vaporized as free atoms, following transformation caused by hydrolysis. The replacement of chlorine atoms by oxygen occurred at lower temperatures for beryllium and aluminium chlorides than for magnesium chloride. There were some particular areas on the platform surface where other mechanisms, such as hydrolysis of calcium chloride and dissociation of sodium chloride in the condensed phase, seemed occasionally to occur to a minor extent.

Castro, M. A.; Faulds, K.; Smith, W. E.; Aller, A. J.; Littlejohn, D.



Calcium and osteoporosis  

Microsoft Academic Search

Calcium is an essential nutrient that is involved in most metabolic processes and the phosphate salts of which provide mechanical rigidity to the bones and teeth, where 99% of the body's calcium resides. The calcium in the skeleton has the additional role of acting as a reserve supply of calcium to meet the body's metabolic needs in states of calcium

B. E. Christopher Nordin



Lithium thionyl chloride battery  

SciTech Connect

The discharge rate and internal conductivity of electrochemical cell including a lithium anode, and a cathode and an electrolyte including LiAlCl4 and SOC2 is improved by the addition of an amount of a mixture containing AlCl3 and butyl pyridinium chloride.

Saathoff, D.J.; Venkatasetty, H.V.



Ferrimagnetic copper chloride hydroxide  

Microsoft Academic Search

Magnetic properties of copper chloride hydroxide were studied by using a superconducting quantum interference device. The coercivity of this material was more than 10 000 Oe at 2 K, which is the highest observed in the copper compounds. The magnetic susceptibility as a function of temperature revealed ferrimagnetism in the sample.

S G Yang; T Li; B L Xu; Y W Du



(Perfluoroalkylimino)selenyl Chlorides.  

National Technical Information Service (NTIS)

Very few examples of compounds containing discrete nitrogen-selenium double bonds exist. The first of these was reported in 1967 and involved the preparation of ((arylsulfonyl)imino)-selenyl chlorides. Other examples such as TeF5N--SeCl2 and SF5N--SeCl2 d...

J. S. Thrasher C. S. Bauknight D. D. DesMarteau




EPA Science Inventory

The photooxidation of allyl chloride was studied by irradiation either in 100-L Teflon bags or in a 22.7-cu m Teflon smog chamber in the presence of added NOx. In the absence of added hydrocarbons, the reaction involves a Cl atom chain, which leads to a highly reactive system. A ...


Photooxidation of Allyl Chloride.  

National Technical Information Service (NTIS)

The photooxidation of allyl chloride was studied by irradiation either in 100-L Teflon bags or in a 22.7-cu m Teflon smog chamber in the presence of added NOx. In the absence of added hydrocarbons, the reaction involves a Cl atom chain, which leads to a h...

E. O. Edney P. B. Shepson T. E. Kleindienst E. W. Corse



Plutonium metal and alloy preparation by molten chloride reduction  

SciTech Connect

Satisfactory reduction of molten plutonium trichloride (pure and in combination with 20 wt % sodium chloride) by calcium, lanthanum, and cerium has been demonstrated on the 10-g scale. The yields were satisfactory for this scale of operation, and it is indicated that these reductions may be useful for large-scale operations. Significant separations of plutonium from rare earth impurities was demonstrated for lanthanum and cerium reductions. Preparation of plutonium-cerium and plutonium-cerium-cobalt alloys during reduction was also demonstrated.

Reavis, J.G.



Relationship of plasma calcium and phosphorus to the shell quality of laying hens receiving saline drinking water.  


1. From 36 to 43 weeks of age 210 White Leghorn laying hens were used to study the relationship of plasma calcium and phosphorus concentrations to egg-shell quality when saline drinking water was given. 2. Seven experimental treatments in which different amounts of sodium chloride were supplied by the food and/or the drinking water were compared. 3. Increasing salt intake through the drinking water or the food reduced shell thickness and shell calcium, and increased the numbers of damaged eggs. Sodium chloride given in the drinking water was more effective in reducing shell quality and increasing plasma calcium and phosphorus than sodium chloride given in the food. PMID:7719739

Pourreza, J; Nili, N; Edriss, M A



Chloride ATPase Pumps in Epithelia  

Microsoft Academic Search

\\u000a Five widely documented mechanisms for chloride transport across biological membranes are known: anion-coupled antiport, Na+ and H(+)-coupled symport, Cl? channels and an electrochemical coupling process. These transport processes for chloride are either secondarily active or\\u000a are driven by the electrochemical gradient for chloride. Until recently, the evidence in favour of a primary active transport\\u000a mechanism for chloride has been inconclusive

George A. Gerencser


Calcium Collage  

NSDL National Science Digital Library

In this activity (on pages 11-14 of PDF), learners cut out pictures from magazines of foods that help make bones strong and glue the pictures to a paper bone. The lesson plan includes information about various activities - including physical exercise as well as diet - that lead to healthy bones. It also includes a list of foods that provide calcium to strengthen bones, including dairy products, spinach, and tofu. The paper bones can be cut out of construction paper prior to the activity.




High-efficiency electroporation by freezing intact yeast cells with addition of calcium.  


We developed a novel freezing method to generate competent cells of Schizosaccharomyces pombe and Saccharomyces cerevisiae prior to electroporation. Freezing the intact cells in sorbitol with the addition of calcium at -80 degrees C allowed us to improve the transformation efficiency after freezing and thawing. The optimum concentration of CaCl(2) was found to be 5-10 mM. The addition of other cations had no effect on the efficiency, while the addition of calcium meant that a broad concentration of sorbitol (0.6-2.5 M) could be used, independent of strain. Moreover, increasing the cell concentration to 2 x 10(9) cells/ml during an applied electric pulse further increased the efficiency after freezing and resulted in a wide range of electric field strength (9.0-11.5 kV/cm). Therefore, there was no need to optimize both the concentration of cryoprotectant and the electric field strength of the applied pulse. This procedure for electroporation allows the frozen competent cells to be stored long-term without any significant loss of efficiency. PMID:12684838

Suga, Minoru; Hatakeyama, Toyomasa



Coexistence of Cu, Fe, Pb, and Zn oxides and chlorides as a determinant of chlorinated aromatics generation in municipal solid waste incinerator fly ash.  


We investigated chemical determinants of the generation of chlorinated aromatic compounds (aromatic-Cls), such as polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs), in fly ash from municipal solid waste incineration. The influences of the following on aromatic-Cls formation in model fly ash (MFA) were systematically examined quantitatively and statistically: (i) inorganic chlorides (KCl, NaCl, CaCl2), (ii) base materials (SiO2, Al2O3, CaCO3), (iii) metal oxides (CuO, Fe2O3, PbO, ZnO), (iv) metal chlorides (CuCl2, FeCl3, PbCl2, ZnCl2), and (v) "coexisting multi-models." On the basis of aromatic-Cls concentrations, the ?CBzs/?PCBs ratio, and the similarity between distribution patterns, MFAs were categorized into six groups. The results and analysis indicated that the formation of aromatic-Cls depended strongly on the "coexistence condition", namely multimodels composed of not only metal chlorides, but also of metal oxides. The precise replication of metal chloride to oxide ratios, such as the precise ratios of Cu-, Fe-, Pb-, and Zn-chlorides and oxides, may be an essential factor in changing the thermochemical formation patterns of aromatic-Cls. Although CuCl2 acted as a promoter of aromatic-Cls generation, statistical analyses implied that FeCl3 also largely influenced the generation of aromatic-Cls under mixture conditions. Various additional components of fly ash were also comprehensively analyzed. PMID:24308371

Fujimori, Takashi; Tanino, Yuta; Takaoka, Masaki



Molecular Structure of Thionyl chloride  

NSDL National Science Digital Library

Thionyl chloride is a slightly yellowish liquid with an intense odor and low viscosity. It reacts with lithium to produce lithium chloride and is a good solvent for most organic compounds. Other uses of thionyl chloride include as an intermediate for the production of pharmaceutically active ingredients, as an electrolyte in lithium batteries, and in crop protection.



The effect of the electrochemical chloride extraction treatment on steel-reinforced mortar. Part II: Microstructural characterization  

SciTech Connect

A study has been made of the changes in cement composition and microstructures resulting from electrochemical chloride extraction applied to mortar samples in which the chlorides were added with the mixing water, ingressed by ponding with an NaCl solution, or both. After exposure for 1 year, specimens with and without chlorides were subjected to an electrochemical chloride extraction treatment. Microstructural analyses of fracture surfaces through the steel/mortar interface revealed a significant alteration of the cementitious phases. In untreated samples, calcium-silicon-rich phases consistent with Types I and II calcium silicate hydrate were observed. After the extraction treatment, these phases were not detectable and instead, sodium-rich, iron-rich, and calcium-aluminum-rich phases were observed.

Marcotte, T.D.; Hansson, C.M.; Hope, B.B.



Calcium source (image)  


Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...


Coronary Calcium Scan  


... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...


Calcium and bones (image)  


Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...


Acute and chronic effects of lithium chloride on physiological and psychological measures in normals  

Microsoft Academic Search

In the acute experiment six healthy volunteers were given orally two doses of lithium chloride, 16 and 32 mmol, and placebo sodium chloride 32 mmol in a double-blind standardized procedure, with a 1-week interval between treatments. Compared to sodium, lithium produced a decrease in subjective well-being, decrease of skin conductance fluctuations, and increase in plasma calcium concentrations. Dose-related effects were

I. G. Karniol; J. Dalton; M. H. Lader



Worker Exposure to Vinyl Chloride in Vinyl Chloride and Polyvinyl Chloride Production and Fabrication.  

National Technical Information Service (NTIS)

In assessment of worker exposure to vinyl-chloride (75014) (VC) and polyvinyl-chloride (9002862) (PVC) was reported. Toxicological data were presented, including acute and chronic animal and human studies, as well as reported worker exposures. Common meth...

J. H. Jones



Electrochemical studies of calcium chloride-based molten salt systems  

SciTech Connect

Conductance and EMF studies of CaCl{sub 2}-based melts were performed in the temperature range 790--990 C. Conductivity data collected using magnesia tubes and capillaries showed deviations from the data recommended by the National Bureau of Standards. These deviations are attributed to the slow dissolution of magnesia by the CaCl{sub 2}-CaO melt. Conductivity data for molten CaCl{sub 2} using a pyrolytic boron nitride capillary were in reasonable agreement with the recommended data; however, undissolved CaO in CaCl{sub 2} may have caused blockage of the pyrolytic boron nitride capillary, resulting in fluctuations in the measured resistance. The utility of the AgCl/Ag reference electrode in CaCl{sub 2}-AgCl and CaCl{sub 2}-CaO-AgCl melts, using asbestos diaphragms and Vycor glass as reference half-cell membranes, was also investigated. Nernstian behavior was observed using both types of reference half-cell membranes in CaCl{sub 2}-AgCl melts. The AgCl/Ag reference electrode also exhibited Nernstian behavior in CaCl{sub 2}-CaO-AgCl melts using a Vycor reference half-cell membrane and a magnesia crucible. The use of CaCl{sub 2} as a solvent is of interest since it is used in plutonium metal purification, as well as various other commercial applications. 97 refs., 33 figs., 13 tabs.

Blanchard, T.P. Jr.



Permeant Anions Control Gating of Calcium-dependent Chloride Channels  

Microsoft Academic Search

The effects of external anions (SCN?, NO3?, I?, Br?, F?, glutamate, and aspartate) on gating of Ca2+-dependent Cl? channels from rat parotid acinar cells were studied using the whole-cell configuration of the patch-clamp technique. Shifts in the reversal potential of the current induced by replacement of external Cl? with foreign anions, gave the following selectivity sequence based on permeability ratios

P. Perez-Cornejo; J. A. De Santiago; J. Arreola



Advanced calcium-thionyl chloride high-power battery  

Microsoft Academic Search

In this phase it is demonstrated that Ca\\/SrX2 + 7 or 20 percent SO2-TC cells (A7 and A20 types) can deliver at RT up to 5.5 Ah at low rates and 4.4 Ah at 0.9 A. These cells have 10 to 80 percent more capacity than have commercial Li-TC and Li-SO2 wound c-size cells. The improved A7 and A20 types

Emanuel Peled



Chloride and Salinity  

NSDL National Science Digital Library

This learning activity from the Advanced Technology Environmental and Energy Center (ATEEC) will provide a good introduction for students studying chloride and salinity. A list of required materials is included as well as the step by step procedure for conducting the experiment. Student worksheets are also included. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.



Urinary inhibitor of the formation of calcium oxalate.  


Normal urine was examined for substances which inhibited the formation of calcium oxalate, using a separation scheme which involved ultrafiltration, alcohol precipitation, electrophoresis and paper chromatography. The major anionic inhibitors were found to be citric acid, isocitric acid and pyrophosphate. The inhibitory activity of urine and that of an artificial urine having the same concentration of urea, creatinine, sodium, potassiu, magnesium, calcium, ammonia, sulphate, chloride, inorganic phosphate, oxalate, citrate, isocitrate and pyrophosphate, and the same pH were identical. This confirmed that urine does not contain an unidentified potent substance which inhibits the formation of calcium oxalate. PMID:223711

Sutor, D J; Percival, J M; Doonan, S



Chloride channels as drug targets  

PubMed Central

Chloride channels represent a relatively under-explored target class for drug discovery as elucidation of their identity and physiological roles has lagged behind that of many other drug targets. Chloride channels are involved in a wide range of biological functions, including epithelial fluid secretion, cell-volume regulation, neuroexcitation, smooth-muscle contraction and acidification of intracellular organelles. Mutations in several chloride channels cause human diseases, including cystic fibrosis, macular degeneration, myotonia, kidney stones, renal salt wasting and hyperekplexia. Chloride-channel modulators have potential applications in the treatment of some of these disorders, as well as in secretory diarrhoeas, polycystic kidney disease, osteoporosis and hypertension. Modulators of GABAA (?-aminobutyric acid A) receptor chloride channels are in clinical use and several small-molecule chloride-channel modulators are in preclinical development and clinical trials. Here, we discuss the broad opportunities that remain in chloride-channel-based drug discovery.

Verkman, Alan S.; Galietta, Luis J. V.



Minerals Yearbook, 1990. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. The 'Calcium and Calcium Compounds Annual Report' includes calciu...

M. M. Miller



Minerals Yearbook, 1989. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or an...

M. M. Miller



The effect of preharvest calcium sprays on quality attributes, physicochemical aspects of cell wall components and susceptibility to brown rot of peach fruits ( Prunus persica L. cv. Andross)  

Microsoft Academic Search

This study was planned to evaluate the effect of preharvest calcium sprays on physicochemical aspects of cell wall components, activity patterns of pectin-modifying enzymes and susceptibility to brown rot (Monilinia fructicola) of peach fruits (Prunus persica L. cv. Andross). Six or 10 preharvest calcium sprays were applied with two different formulas (calcium chloride and an ethylenediamine tetraacetic acid (EDTA) chelated

G. A. Manganaris; M. Vasilakakis; I. Mignani; G. Diamantidis; K. Tzavella-Klonari



Air bubble contact with endothelial cells in vitro induces calcium influx and IP3-dependent release of calcium stores.  


Gas embolism is a serious complication of decompression events and clinical procedures, but the mechanism of resulting injury remains unclear. Previous work has demonstrated that contact between air microbubbles and endothelial cells causes a rapid intracellular calcium transient and can lead to cell death. Here we examined the mechanism responsible for the calcium rise. Single air microbubbles (50-150 ?m), trapped at the tip of a micropipette, were micromanipulated into contact with individual human umbilical vein endothelial cells (HUVECs) loaded with Fluo-4 (a fluorescent calcium indicator). Changes in intracellular calcium were then recorded via epifluorescence microscopy. First, we confirmed that HUVECs rapidly respond to air bubble contact with a calcium transient. Next, we examined the involvement of extracellular calcium influx by conducting experiments in low calcium buffer, which markedly attenuated the response, or by pretreating cells with stretch-activated channel blockers (gadolinium chloride or ruthenium red), which abolished the response. Finally, we tested the role of intracellular calcium release by pretreating cells with an inositol 1,4,5-trisphosphate (IP3) receptor blocker (xestospongin C) or phospholipase C inhibitor (neomycin sulfate), which eliminated the response in 64% and 67% of cases, respectively. Collectively, our results lead us to conclude that air bubble contact with endothelial cells causes an influx of calcium through a stretch-activated channel, such as a transient receptor potential vanilloid family member, triggering the release of calcium from intracellular stores via the IP3 pathway. PMID:21633077

Sobolewski, Peter; Kandel, Judith; Klinger, Alexandra L; Eckmann, David M



Calcium-labile mitotic spindles isolated from sea urchin eggs (Lytechinus variegatus).  


We isolated calcium-labile mitotic spindles from eggs of the sea urchin Lytechinus variegatus, using a low ionic strength, EGTA lysis buffer that contined 5.0 mM EGTA, 0.5 mM MgCl2, 10-50 mM PIPES, pH 6.8, with 1% Nonidet P-40 (detergent) and 20-25% glycerol. Isolated spindles were stored in EGTA buffer with 50% glycerol for 5-6 wk without deterioration. The isolated spindles were composed primarily of microtubules with the chromosomes attached. No membranes were seen. Isolated spindles, perfused with EGTA buffer to remove the detergent and glycerol, had essentially the same birefringent retardation (BR) as spindles in vivo at the same mitotic stage. Even in the absence of glycerol and exogenous tubulin, the isolated spindles were relatively stable in the EGTA buffer: BR decayed slowly to about half the initial value within 30-45 min. However, both the rate and extent of BR decay increased with concentrations of Ca2+ above 0.2-0.5 muM as assayed using Ca-EGTA buffers (0.2 mM EGTA, 0.5 mM MgCl2, 50 mM PIPES, pH 6.8, plus various amounts of CaCl2). Microtubules depolymerized almost completely in < 6 min at Ca2+ concentrations of 2 muM and within several seconds at 10 muM Ca2+. Of several divalent cations tested, only Sr2+ caused comparable changes in BR. The absence of membranes in the isolated spindles appeared to be associated with a lack of calcium-sequestering ability. Our results suggest that calcium ions play an important role in the depolymerization of spindle microtubules and that membrane components may function within the mitotic apparatus of living cells to sequester and release calcium ions during mitosis. PMID:7190569

Salmon, E D; Segall, R R



A comparative study of two clerodane diterpenes from Baccharis trimera (Less.) DC. on the influx and mobilization of intracellular calcium in rat cardiomyocytes.  


Baccharis trimera (Less.) D.C. (Asteraceae) is a medicinal species native to South America and used in Brazilian folk medicine to treat gastrointestinal and liver diseases, kidney disorders and diabetes. The aqueous extract (AE) of the aerial parts of this species presented two mainly constituents: the ent-clerodane diterpene (Fig. 1) and the neo-clerodane diterpene (Fig. 2). The objective of this work was to study their activities on the blockade of Ca(2+)-induced contractions in KCL-depolarized rat portal vein preparations, and on the influx and mobilization of cytosolic calcium in rat cardiomyocytes by fluorescence measurements. The results showed that both the neo- and the ent-clerodane diterpenes reduced the maximal contractions induced by CaCl2, in KCl depolarized rat portal vein preparations, without modifying the EC50. The data on the concentration of cytosolic calcium ([Ca(2+)]c) showed that, while the neo-clerodane diterpene stimulates the mobilization of [Ca(2+)]c in rat cardiomyocytes, this effect was not observed with the ent-clerodane diterpene. On the other hand, the influx of calcium was not altered by the neo-clerodane diterpene, but was reduced in the presence of the ent-clerodane diterpene, indicating that this compound induces a blockade of the voltage-dependent calcium channels. PMID:24837474

Garcia, Francisca Adilfa de Oliveira; Tanae, Mirtes Midori; Torres, Luce Maria Brando; Lapa, Antnio Jos; de Lima-Landman, Maria Teresa Riggio; Souccar, Caden



Fractional Absorption of Active Absorbable Algal Calcium (AAACa) and Calcium Carbonate Measured by a Dual Stable-Isotope Method  

PubMed Central

With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa), obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI), with that of calcium carbonate. In 10 postmenopausal women volunteers aged 59 to 77 years (mean S.D., 67 5.3), the fractional calcium absorption of AAACa and CaCO3 was measured by a dual stable isotope method. 44Ca-enriched CaCO3 and AAACa were administered in all subjects one month apart. After a fixed-menu breakfast and pre-test urine collection (Urine 0), 42Ca-enriched CaCl2 was intravenously injected, followed by oral administration of 44Ca-enriched CaCO3 without carrier 15 minutes later, and complete urine collection for the next 24 hours (Urine 24). The fractional calcium absorption was calculated as the ratio of Augmentation of 44Ca from Urine 0 to Urine 24/ augmentation of 42Ca from Urine 0 to Urine 24. Differences and changes of 44Ca and 42Ca were corrected by comparing each with 43Ca. Fractional absorption of AAACa (mean S.D., 23.1 6.4), was distinctly and significantly higher than that of CaCO3 (14.7 6.4; p = 0.0060 by paired t-test). The mean fractional absorption was approximately 1.57-times higher for AAACa than for CaCO3. The serum 25(OH) vitamin D level was low (mean S.D., 14.2 4.95 ng/ml), as is common in this age group in Japan. Among the parameters of the bone and mineral metabolism measured, none displayed a significant correlation with the fractional absorption of CaCO3 and AAACa. Higher fractional absorption of AAACa compared with CaCO3 supports previous reports on the more beneficial effect of AAACa than CaCO3 for osteoporosis.

Uenishi, Kazuhiro; Fujita, Takuo; Ishida, Hiromi; Fujii, Yoshio; Ohue, Mutsumi; Kaji, Hiroshi; Hirai, Midori; Kakumoto, Mikio; Abrams, Steven A.



The binding of calcium ions by erythrocytes and `ghost'-cell membranes  

PubMed Central

1. Washed human erythrocytes, suspended in iso-osmotic sucrose containing 2.5mm-calcium chloride, bind about 400?g-atoms of calcium/litre of packed cells. Sucrose may be replaced by other sugars. 2. Partial replacement of sucrose by iso-osmotic potassium chloride diminishes the uptake of calcium, 50% inhibition occurring at about 50mm-potassium chloride. 3. Other univalent cations behave like potassium, whereas bivalent cations are much more inhibitory. The tervalent cations, yttrium and lanthanum, however, are the most effective inhibitors of calcium uptake. 4. An approximate correlation exists between the calcium uptake and the sialic acid content of erythrocytes of various species and of human erythrocytes that have been partially depleted of sialic acid by treatment with neuraminidase. However, even after complete removal of sialic acid, human erythrocytes still bind about 140?g-atoms of calcium/litre of packed cells. 5. A Scatchard (1949) plot of calcium uptake at various Ca2+ concentrations in the suspending media shows the presence of three different binding sites on the external surface of the human erythrocyte membrane. 6. Erythrocyte `ghost' cells, the membranes of which appear to be permeable to Ca2+ ions, can bind about 1000?g-atoms of calcium per `ghost'-cell equivalent of 1 litre of packed erythrocytes. This indicates that there are also binding sites for calcium on the internal surface of the erythrocyte membrane.

Long, C.; Mouat, Barbara



A rapid method for the estimation of calcium and magnesium carbonates in limestones, dolomite and other calcareous materials  

Microsoft Academic Search

Summary Calcium and magnesium carbonates are determined in minerals by dissolving the sample in ammonium chloride solution and subsequent chelatometric titration. Iron and aluminium are dissolved, it any, in traces only.

Suresh Singh; Kali Prasad Gupta



Strength, porosity, and chloride resistance of mortar using the combination of two kinds of pozzolanic materials  

NASA Astrophysics Data System (ADS)

This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ordinary Portland cement (CT) was blended with a single pozzolan and two pozzolans. Strength, porosity, rapid chloride penetration, immersion, and corrosion tests were performed to characterize the mortar. Test results showed that the use of ternary blends of CT, FA, and RB or BA decreased the porosity of the mortar, as compared with binary blended mortar containing CT and RB or BA. The resistance to chloride penetration of the mortar improved substantially with partial replacement of CT with FA, RB, and BA. The use of ternary blends of CT, FA and RB or BA produced the mortar with good strength and resistance to chloride penetration. The resistance to chloride penetration was higher with an increase in the replacement level due to the reduced calcium hydroxide.

Rukzon, Sumrerng; Chindaprasirt, Prinya



Laboratory study on the high-temperature capture of HCl gas by dry-injection of calcium-based sorbents.  


This is a laboratory study on the reduction of combustion-generated hydrochloric acid (HCl) emissions by in-furnace dry-injection of calcium-based sorbents. HCl is a hazardous gaseous pollutant emitted in significant quantities by municipal and hazardous waste incinerators, coal-fired power plants, and other industrial furnaces. Experiments were conducted in a laboratory furnace at gas temperatures of 600-1000 degrees C. HCl gas diluted with N2, and sorbent powders fluidized in a stream of air were introduced into the furnace concurrently. Chlorination of the sorbents occurred in the hot zone of the furnace at gas residence times approximately 1 s. The sorbents chosen for these experiments were calcium formate (CF), calcium magnesium acetate (CMA), calcium propionate (CP), calcium oxide (CX), and calcium carbonate (CC). Upon release of organic volatiles, sorbents calcine to CaO at approximately 700 degrees C, and react with the HCl according to the reaction CaO + 2HCl <=> CaCl2 + H2O. At the lowest temperature case examined herein, 600 degrees C, direct reaction of HCl with CaCO3 may also be expected. The effectiveness of the sorbents to capture HCl was interpreted using the "pore tree" mathematical model for heterogeneous diffusion reactions. Results show that the thin-walled, highly porous cenospheres formed from the pyrolysis and calcination of CF, CMA, and CP exhibited high relative calcium utilization at the upper temperatures of this study. Relative utilizations under these conditions reached 80%. The less costly low-porosity sorbents, calcium carbonate and calcium oxide also performed well. Calcium carbonate reached a relative utilization of 54% in the mid-temperature range, while the calcium oxide reached an 80% relative utilization at the lowest temperature examined. The data matched theoretical predictions of sorbent utilization using the mathematical model, with activation energy and pre-exponential factors for the calcination reaction of 17,000 K and 300,000 (g gas/cm2/s/atm gas), respectively. Thus, the kinetics of the calcination reaction were found to be much faster (approximately 500 times) than those of the sulfation reaction examined previously in this laboratory. PMID:11219704

Shemwell, B; Levendis, Y A; Simons, G A



Removal of hydrogen chloride from high temperature coal gases  

SciTech Connect

The chlorine content of U.S. coals ranges from 0.01 to 0.5%, and some coals in U.K. contain as high as 1.0% chlorine. This element is present in the coal mainly as alkali chlorides, but it also occurs as oxychlorides of calcium and magnesium. The presence of HCl in the coal gas can lead to corrosion of metallic and ceramic components of the gasifier, attack gas turbine components and to poisoning of molten carbonate fuel cell electrodes. Morgantown Energy Technology Center, as the U.S. Department of Energy's lead center for coal gasification and gas stream cleanup technology, has been concerned for some years with the purification of coal-derived gases for a range of applications including gas turbine, fuel-cell, and combined-cycle power generation. This paper presents the results of a laboratory-scale evaluation conducted at SRI International to determine the effectiveness of naturally occurring minerals and commercially available sorbents to remove HCl vapor from simulated coal gas streams at temperatures from 550/sup 0/ to 650/sup 0/C. The thermodynamic stability and the volatility of the solid chloride products were the major criteria in selecting the nature of the sorbent. Alkaline earth chlorides, generally, are less volatile than alkali metal chlorides and transition metal. Bench-scale experiments were also conducted with these sorbents at the Institute of Gas Technology, Chicago, IL. The rate of chloride uptake was calculated from the analysis of the chloride content of the spent sorbent as a function of the bed depth. The results of bench-scale experiments were in general agreement with the laboratory-scale experiments although the HCl removal rate and the chloride capacities were somewhat lower than found in the laboratory-scale experiments.

Krishnan, G.N.; Wood, B.J.; Tong, G.T. (SRI International, 333 Ravenswood Avenue, Menlo Park, CA (US)); Kothari, V.P. (U.S. Dept. of Energy, Morgantown Energy Technology Center, 3600 Collins Ferry Road, Morgantown, WV (US))



Calcium ?-Hydroxy-?-Methylbutyrate  

Microsoft Academic Search

The binding capacity of calcium ?-hydroxy-?-methylbutyrate (calcium HMB), compared to other binders, was investigated in an in vitro study. Fifty milli-equivalents of either calcium HMB, calcium acetate, calcium carbonate, aluminum hydroxide gel or non-gel aluminum hydroxide was added to a phosphate solution, titrated (HC1 or NaOH), shaken and centrifuged to four different pH levels at 37 C (simulating the gastrointestinal

Mauri F. Sousa; Naji N. Abumrad; Cristina Martins; Steven Nissen; Miguel C. Riella



Exogenous calcium alleviates low night temperature stress on the photosynthetic apparatus of tomato leaves.  


The effect of exogenous CaCl2 on photosystem I and II (PSI and PSII) activities, cyclic electron flow (CEF), and proton motive force of tomato leaves under low night temperature (LNT) was investigated. LNT stress decreased the net photosynthetic rate (Pn), effective quantum yield of PSII [Y(II)], and photochemical quenching (qP), whereas CaCl2 pretreatment improved Pn, Y(II), and qP under LNT stress. LNT stress significantly increased the non-regulatory quantum yield of energy dissipation [Y(NO)], whereas CaCl2 alleviated this increase. Exogenous Ca2+ enhanced stimulation of CEF by LNT stress. Inhibition of oxidized PQ pools caused by LNT stress was alleviated by CaCl2 pretreatment. LNT stress reduced zeaxanthin formation and ATPase activity, but CaCl2 pretreatment reversed both of these effects. LNT stress caused excess formation of a proton gradient across the thylakoid membrane, whereas CaCl2 pretreatment decreased the said factor under LNT. Thus, our results showed that photoinhibition of LNT-stressed plants could be alleviated by CaCl2 pretreatment. Our findings further revealed that this alleviation was mediated in part by improvements in carbon fixation capacity, PQ pools, linear and cyclic electron transports, xanthophyll cycles, and ATPase activity. PMID:24828275

Zhang, Guoxian; Liu, Yufeng; Ni, Yang; Meng, Zhaojuan; Lu, Tao; Li, Tianlai



Exogenous Calcium Alleviates Low Night Temperature Stress on the Photosynthetic Apparatus of Tomato Leaves  

PubMed Central

The effect of exogenous CaCl2 on photosystem I and II (PSI and PSII) activities, cyclic electron flow (CEF), and proton motive force of tomato leaves under low night temperature (LNT) was investigated. LNT stress decreased the net photosynthetic rate (Pn), effective quantum yield of PSII [Y(II)], and photochemical quenching (qP), whereas CaCl2 pretreatment improved Pn, Y(II), and qP under LNT stress. LNT stress significantly increased the non-regulatory quantum yield of energy dissipation [Y(NO)], whereas CaCl2 alleviated this increase. Exogenous Ca2+ enhanced stimulation of CEF by LNT stress. Inhibition of oxidized PQ pools caused by LNT stress was alleviated by CaCl2 pretreatment. LNT stress reduced zeaxanthin formation and ATPase activity, but CaCl2 pretreatment reversed both of these effects. LNT stress caused excess formation of a proton gradient across the thylakoid membrane, whereas CaCl2 pretreatment decreased the said factor under LNT. Thus, our results showed that photoinhibition of LNT-stressed plants could be alleviated by CaCl2 pretreatment. Our findings further revealed that this alleviation was mediated in part by improvements in carbon fixation capacity, PQ pools, linear and cyclic electron transports, xanthophyll cycles, and ATPase activity.

Ni, Yang; Meng, Zhaojuan; Lu, Tao; Li, Tianlai



Magnesium-lead chloride batteries  

Microsoft Academic Search

The preparation of lead chloride cathodes, and their discharge in magnesium-lead chloride batteries, is described. The lead chloride blended with graphite is pasted on grids of expanded copper, using urea formaldehyde solutions as the binder. One-, five-, and fifteen-cell batteries were discharged at temperatures between -40C and +45C, at low current drains. For five-cell batteries energy densities in the range

J. R. Coleman



Calcium metabolism and bone calcium content in normal and oophorectomized rats consuming various levels of saline for 12 months.  


The effect of different intakes of salt for 12 mo on bone calcium content and urinary excretion of calcium and hydroxyproline were examined in sham operated and oophorectomized (OX) rats to determine the long term effects of high sodium intake and its interaction with estrogen deficiency. Sham operated (n = 24) and OX (n = 24) rats were divided into groups of six rats in a 2 x 4 design. One group of sham and one of OX rats were given 0, 2, 6 or 18 g/L sodium chloride to drink. Urine samples were collected at 0, 2, 4, 6, 10 and 12 mo for the measurement of sodium, calcium, creatinine and hydroxyproline. At the end of 12 mo, blood was taken for measurement of calcium, albumin, alkaline phosphatase and creatinine and the left femur was removed and analyzed for calcium and phosphate. Body weights of the OX rats were higher than the sham operated controls. At the start of the experiment (10 d after OX) urinary excretions of calcium and hydroxyproline were significantly higher in OX rats. However, after 4-6 mo, they were significantly lower in OX rats. Calcium excretion and hydroxyproline excretion were increased by high salt intake, and there was a significant correlation between sodium and calcium excretion (r = 0.962). Bone calcium content of OX rats was lower than their corresponding sham-operated controls. Sodium intake also had a significant effect on bone calcium content. Multiple regression analysis showed that OX and sodium intake explained 7.6% and 1.5% of the variation in bone calcium content. We conclude that high sodium intake causes increased loss of calcium and reduces bone calcium content in sham-operated as well as OX rats. PMID:9482774

Chan, E L; Swaminathan, R



Calcium antagonist and antiperoxidant properties of some hindered phenols.  

PubMed Central

1. The calcium antagonist and antioxidant activities of certain synthetic and natural phenols, related to BHA (2-t-butyl-4-methoxyphenol), were evaluated in rat ileal longitudinal muscle and in lipid peroxidation models respectively. 2. Compounds with a phenol or a phenol derivative moiety, with the exception of 2,2'-dihydroxy-3,-3'-di-t-butyl-5,5'-dimethoxydiphenyl (di-BHA), inhibited in a concentration-dependent manner the BaCl2-induced contraction of muscle incubated in a Ca(2+)-free medium. Calculated pIC50 (M) values ranged between 3.32 (probucol) and 4.96 [3,5-di-t-butyl-4-hydroxyanisole (di-t-BHA)], with intermediate activity shown by khellin < gossypol < quercetin < 3-t-butylanisole < BHA < nordihydroguaiaretic acid (NDGA) < 2,6-di-t-butyl-4-methylphenol (BHT) and papaverine. 3. The Ca2+ channel activator Bay K 8644 overcame the inhibition sustained by nifedipine, BHA and BHT, while only partially reversing that of papaverine. 4. BHA, BHT, nifedipine and papaverine also inhibited in a concentration-dependent fashion CaCl2 contractions of muscle depolarized by a K(+)-rich medium. This inhibition appeared to be inversely affected by the Ca(2+)-concentration used. 5. The inhibitory effects of nifedipine, papaverine, BHA and BHT were no longer present when muscle contraction was elicited in skinned fibres by 5 microM Ca2+ or 500 microM Ba2+, suggesting a plasmalemmal involvement of target sites in spasmolysis. 6. Comparative antioxidant capability was assessed in two peroxyl radical scavenging assay systems. These were based either on the oxidation of linoleic acid initiated by a heat labile azo compound or on lipid peroxidation of rat liver microsomes promoted by Fe2+ ions.(ABSTRACT TRUNCATED AT 250 WORDS)

Sgaragli, G. P.; Valoti, M.; Gorelli, B.; Fusi, F.; Palmi, M.; Mantovani, P.



Study on industrial synthesis of poly aluminum chloride and coagulation effect with different basicities  

Microsoft Academic Search

In this experimental study, the industrial technique of the one-step method of dissolving the calcium aluminate with the hydrochloric acid to synthesize Poly Aluminum Chloride (PAC) was simulated. And effects of technical conditions were also researched. On these bases, the effects of different basicities on PAC coagulation were studied for the water treatment of Mopanshan reservoir.

Zhen Zhang; Di Guan; Hui Liu; Xing Li



Insolubilization of potassium chloride crystals in Tradescantia pallida.  


Calcium oxalate crystals are by far the most prevalent and widely distributed mineral deposits in higher plants. In Tradescantia pallida, an evergreen perennial plant widely used as an ornamental plant, calcium oxalate crystals occur in the parenchymal tissues of stem, leaf, and root, as well as in flower organs, in the form of either raphides or tetragonal prismatic crystals or both. Energy-dispersive X-ray analysis revealed that C, O, and Ca were the main elements; and K, Cl, and Si, the minor elements. Infrared and X-ray analyses of crystals collected from these tissues detected the coexistence of two calcium oxalate chemical forms, i.e., whewellite and weddellite, as well as calcite, opal, and sylvite. Here, we show for the first time the occurrence of epitaxy in mineral crystals of plants. Epitaxy, which involves the oriented overgrowth of one crystal onto a second crystalline substrate, might explain how potassium chloride (sylvite)--one of the most water-soluble salts--stays insoluble in crystal form when coated with a calcium oxalate epilayer. The results indicate the potential role of crystals in regulating the ionic equilibrium of both calcium and potassium ions. PMID:17762907

Brizuela, M; Montenegro, T; Carjuzaa, P; Maldonado, S



Chloride removal from recycled cooling water using ultra-high lime with aluminum process.  


Chloride is a deleterious ionic species in cooling water systems because it promotes corrosion, and most of the scale and corrosion inhibitors are sensitive to chloride concentration in the water. Chloride can be removed from cooling water by precipitation as calcium chloroaluminate [Ca4Al2Cl2(OH)12]. A set of equilibrium experiments and one kinetic experiment were conducted to evaluate chloride removal using the ultra-high lime with aluminum (UHLA) process and to characterize the equilibrium conditions of calcium chloroaluminate precipitation. A total of 48 batch-equilibrium experiments were conducted on a 30 mM NaCl solution over a range of values for lime dose (0 to 200 mM) and sodium aluminate dose (0 to 100 mM). Experimental results showed that the UHLA process can remove chloride and that the formation of a calcium chloroaluminate solid phase is a reasonable mechanism that is able to adequately describe experimental results. An average value of the ion activity product of 10(-94.75) was obtained and can be used as an estimate of the solubility product for Ca4Al2Cl2(OH)12. PMID:12150248

Abdel-Wahab, Ahmed; Batchelor, Bill



Preparation and Characterization of Calcium Carbonate Nanoparticles  

NASA Astrophysics Data System (ADS)

Taking calcium supplements can reduce the risk of developing osteoporosis, but they are not readily absorbed in the gastrointestinal tract. Nanotechnology is expected to resolve this problem. In this study, we prepared and characterized calcium carbonate nanoparticle to improve the solubility by using bottom-up method. The experiment was done by titrating calcium chloride with sodium carbonate with the addition of polyvinylpyrrolidone (PVP) as stabilizer, using ultra-turrax. Various concentrations of calcium chloride and sodium carbonate as well as various speed of stirring were used to prepare the calcium carbonate nanoparticles. Evaluations studied were including particle size, polydispersity index (PI) and zeta potential with particle analyzer, surface morphology with scanning electron microscope, and saturated solubility. In addition, to test the ability of PVP to prevent particles growth, short stability study was performed by storing nano CaCO3 suspension at room temperature for 2 weeks. Results show that using 8000 rpm speed of stirring, the particle size tends to be bigger with the range of 500-600 nm (PI between 0.2-0.4) whereas with stirring speed of 4000 rpm, the particle size tends to be smaller with 300-400 nm (PI between 0.2-0.4). Stirring speed of 6000 rpm produced particle size within the range of 400-500 nm (PI between 0.2-0.4). SEM photograph shows that particles are monodisperse confirming that particles were physically stable without any agglomeration within 2 weeks storage. Taken together, nano CaCO3 is successfully prepared by bottom-up method and PVP is a good stabilizer to prevent the particle growth.

Hassim, Aqilah; Rachmawati, Heni



Ketamine-inhibition of calcium-induced contractions in depolarized rat uterus: a comparison with other calcium antagonists.  

PubMed Central

The inhibitory effect of the intravenous anaesthetic ketamine on CaCl2-induced contractions in the isolated K+-depolarized uterus of the rat in Ca2+-free medium was compared with that produced by papaverine, theophylline and the calcium entry blocker verapamil. Pre-incubation for 20 min with either ketamine (0.3 to 3 mM), papaverine (3 to 30 microM), theophylline (0.1 to 1 mM) or verapamil (3 to 30 nM) induced parallel, concentration-dependent rightward displacements of the dose-response curves to Ca2+ (0.04 to 22 mM). The antagonism was competitive, except that due to verapamil, the Schild plot for which yielded a slope which differed significantly from unity. The calculated pA2 values (+/- s.e.mean) were: ketamine 3.90 +/- 0.07; papaverine 5.55 +/- 0.05; theophylline 3.99 +/- 0.1 and verapamil 9.54 +/- 0.24. These drugs differed in their ability to relax the sustained contraction induced by Ca2+ (1 mM) in K+-depolarizing solution. Ketamine and verapamil relaxed the preparation in a concentration-dependent manner whereas theophylline and especially papaverine were less potent and induced only partial maximal relaxation. The t1/2 of the relaxant effect was significantly less for ketamine than for verapamil (5 and 22 min, respectively). Only ketamine produced a relaxation comparable to that obtained by washing the preparation with Ca2+-free solution (t1/2 = approx. 5 min). Prior exposure of the depolarized uterine strip to a low concentration of Ca2+ (0.22 mM) increased the potency of ketamine, but decreased that of papaverine and theophylline, in antagonizing Ca2+ induced contractions. In contrast, this procedure did not affect the potency of verapamil.(ABSTRACT TRUNCATED AT 250 WORDS)

Calixto, J. B.; Loch, S.



High calcium diet augments vascular potassium relaxation in hypertensive rats.  


The effects of increased dietary calcium on the development of hypertension and vascular smooth muscle responses were studied in spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. Both hypertensive and normotensive animals were divided into two groups; the calcium content of the normal diet was 1.1% and that of the high calcium diet 3.1%. During the 12-week study, calcium supplementation significantly attenuated the increase in systolic blood pressure in the hypertensive rats but did not affect blood pressure in the normotensive rats. The contractile responses of endothelium-denuded mesenteric arterial rings to potassium chloride were similar in all study groups. The contractions to norepinephrine were not altered by the high calcium diet either, but smooth muscle sensitivity to this agonist was lower in the normotensive than in the hypertensive rats. Potassium relaxation was used to evaluate the activity of vascular smooth muscle Na+,K(+)-ATPase. The maximal rate of potassium relaxation was fastest in the normotensive groups but was also clearly faster in calcium-treated hypertensive rats when compared with hypertensive rats on a normal diet. Platelets were used as a cell model for the analysis of intracellular free calcium concentration, which was measured by the fluorescent indicator quin-2. Intracellular free calcium was significantly reduced in the hypertensive rats by calcium supplementation and was not affected in the normotensive rats. In conclusion, a reduction of intracellular free calcium concentration indicating improved calcium regulation and a concomitant alteration in vascular relaxation probably reflecting increased activity of smooth muscle Na+,K(+)-ATPase may contribute to the blood pressure-lowering effect of a high calcium diet. PMID:1730443

Prsti, I; Arvola, P; Wuorela, H; Vapaatalo, H



Novel technique for phosphorus recovery from aqueous solutions using amorphous calcium silicate hydrates (A-CSHs).  


A novel technique for phosphorus (P) recovery from aqueous solutions was developed using amorphous calcium silicate hydrates (A-CSHs). A-CSHs, which have a high Ca/Si molar ratio of 2.0 or greater, could be synthesized using unlimitedly available, inexpensive materials such as siliceous shale and calcium hydroxide. A-CSHs showed high performance for P recovery from an anaerobic sludge digestion liquor (ASDL) and the synthetic model liquor (s-ASDL) containing 89mg PO4-P/L. After 20min mixing, 1.5g/L A-CSHs could remove approximately 69 and 73% PO4-P from ASDL and s-ASDL, respectively. By contrast, autoclaved lightweight concrete particles, which contained crystalline calcium silicate hydrates as a principal component, removed only 10 and 6% PO4-P from ASDL and s-ASDL, respectively, under the same experimental conditions. When A-CSHs were washed with deionized water to remove free Ca(OH)2, P removability was significantly improved (up to 82%) despite the reduction in the amount of Ca(2+) released. Unlike in the case of Ca(OH)2, nosignificant carbonate inhibition was observed with P removal by A-CSHs. Moreover, Premoved by A-CSHs showed better settleability, filterability, and dewaterability than Pprecipitated with conventional CaCl2 and Ca(OH)2. The present study demonstrated that A-CSHs have great potential as a novel, beneficial material for P recovery and recycling. PMID:23497975

Okano, Kenji; Uemoto, Masahide; Kagami, Jumpei; Miura, Keiichi; Aketo, Tsuyoshi; Toda, Masaya; Honda, Kohsuke; Ohtake, Hisao



Molecular Structure of Picryl chloride  

NSDL National Science Digital Library

Picryl chloride is ranked as one of the 100 most commonly found explosive and shock sensitive materials. It is made by reacting 2,4,6 trinitrophenol with thionyl chloride. This highly reactive compound is known to be hazardous and toxic, and to cause liver injury in mice. It is often used as a sensitization agent in mice when their cells undergo hypersensitivity studies.



Benzalkonium chloride and glaucoma.  


Glaucoma patients routinely take multiple medications, with multiple daily doses, for years or even decades. Benzalkonium chloride (BAK) is the most common preservative in glaucoma medications. BAK has been detected in the trabecular meshwork (TM), corneal endothelium, lens, and retina after topical drop installation and may accumulate in those tissues. There is evidence that BAK causes corneal and conjunctival toxicity, including cell loss, disruption of tight junctions, apoptosis and preapoptosis, cytoskeleton changes, and immunoinflammatory reactions. These same effects have been reported in cultured human TM cells exposed to concentrations of BAK found in common glaucoma drugs and in the TM of primary open-angle glaucoma donor eyes. It is possible that a relationship exists between chronic exposure to BAK and glaucoma. The hypothesis that BAK causes/worsens glaucoma is being tested experimentally in an animal model that closely reflects human physiology. PMID:24205938

Rasmussen, Carol A; Kaufman, Paul L; Kiland, Julie A



Thermochemistry of Charge-Unsymmetrical Binary Fused Halide Systems. Ii. Mixtures of Magnesium Chloride with the Alkali Chlorides and with Silver Chloride.  

National Technical Information Service (NTIS)

The integral enthalpies of mixing of the liquid mixtures of magnesium chloride with the alkali chlorides and with silver chloride were determined calorimetrically. The magnesium chloride-silver chloride system is slightly endothermic, while the alkali chl...

O. J. Kleppa F. G. McCarty



Effect of postharvest treatments and storage temperatures on the quality and shelf life of sweet pepper ( Capsicum annum L.)  

Microsoft Academic Search

The effect of salicylic acid (SA) and calcium chloride (CaCl2) treatments on the physicochemical characteristics, softening and antioxidative enzyme activities of sweet pepper fruits packaged in plastic (polythene) bags and stored at 25C and 10C were evaluated at 0, 9 and 18 days of storage period. The activities of cell wall modifying enzymes such as polygalacturonase (PG), pectin methyl esterase

T. V. Ramana Rao; Neeta B. Gol; Khilana K. Shah


Banana Fruit Ripening as Influenced by Edible Coatings  

Microsoft Academic Search

The effects of chitosan 1% and 1.5%, calcium chloride (CaCl2) 1% and 1.5%, chitosan 1% + gibberellic acid 100 ppm, chitosan 1.5% + gibberellic acid 100 ppm, jojoba wax, and glycerol (98%) coatings were evaluated on the shelf life and postharvest quality characteristics of banana fruits stored at 34 1C and 7075% relative humidity, while uncoated fruits served as

Neeta B. Gol; T. V. Ramana Rao



A study towards release dynamics of thiram fungicide from starchalginate beads to control environmental and health hazards  

Microsoft Academic Search

In order to make the judicious use of thiram fungicide we have developed starch- and alginate-based controlled and sustained agrochemical delivery system in the form of beads using calcium chloride (CaCl2) as crosslinker. The beads were characterized by FTIR and swelling studies. To study the effect of composition of the beads on the release dynamics of fungicide (thiram), beads were

Baljit Singh; D. K. Sharma; Atul Gupta



A Novel Approach to the Oral Delivery of Micro or Nanoparticles  

Microsoft Academic Search

A novel oral multiple-unit dosage form which overcame many of the problems commonly observed during the compression of microparticles into tablets was developed in this study. Micro- or nano-particles were entrapped in beads formed by ionotropic gelation of the charged polysaccharide, chitosan or sodium alginate, in solutions of the counterion, tripolyphosphate (TPP) or calcium chloride (CaCl2), respectively. The described technique

Roland Bodmeier; Huagang Chen; Ornlaksana Paeratakul



Action potentials and net membrane currents of isolated smooth muscle cells (urinary bladder of the guinea-pig)  

Microsoft Academic Search

1.Cells were isolated by incubating chunks of tissue from the urinary bladder of the guinea-pig in a high potassium, low chloride medium containing 0.2 mM calcium plus the enzymes collagenase and pronase. After isolation, the cells were superfused with a physiological salt solution (PSS) containing 150 mM NaCl, 3.6 mM CaCl2 and 5.4 mM KCl (35C). Patch electrodes filled with

U. Kliickner; G. Isenberg



75 FR 33824 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...No. 731-TA-149 (Third Review)] Barium Chloride From China Determination On the...revocation of the antidumping duty order on barium chloride from China would be likely to...Publication 4157 (June 2010), entitled Barium Chloride from China: Investigation...



75 FR 19657 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013

...No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States...concerning the antidumping duty order on barium chloride from China...revocation of the antidumping duty order on barium chloride from China would be likely...



49 CFR 173.322 - Ethyl chloride.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation...Preparation and Packaging § 173.322 Ethyl chloride. Ethyl chloride must be packaged in any of the following...



21 CFR 582.5446 - Manganese chloride.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food...Dietary Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...



Effect of Calcium Sprays on Mechanical Strength and Cell Wall Fractions of Herbaceous Peony (Paeonia Lactiflora Pall.) Inflorescence Stems  

PubMed Central

Calcium is an essential element and imparts significant structural rigidity to the plant cell walls, which provide the main mechanical support to the entire plant. In order to increase the mechanical strength of the inflorescence stems of herbaceous peony, the stems are treated with calcium chloride. The results shows that preharvest sprays with 4% (w/v) calcium chloride three times after bud emergence are the best at strengthening Da Fugui peonies stems. Calcium sprays increased the concentrations of endogenous calcium, total pectin content as well as cell wall fractions in herbaceous peonies stems, and significantly increased the contents of them in the top segment. Correlation analysis showed that the breaking force of the top segment of peonies stems was positively correlated with the ratio of water insoluble pectin to water soluble pectin (R = 0.673) as well as lignin contents (R = 0.926) after calcium applications.

Li, Chengzhong; Tao, Jun; Zhao, Daqiu; You, Chao; Ge, Jintao



Effect of calcium sprays on mechanical strength and cell wall fractions of herbaceous peony (paeonia lactiflora pall.) inflorescence stems.  


Calcium is an essential element and imparts significant structural rigidity to the plant cell walls, which provide the main mechanical support to the entire plant. In order to increase the mechanical strength of the inflorescence stems of herbaceous peony, the stems are treated with calcium chloride. The results shows that preharvest sprays with 4% (w/v) calcium chloride three times after bud emergence are the best at strengthening "Da Fugui" peonies' stems. Calcium sprays increased the concentrations of endogenous calcium, total pectin content as well as cell wall fractions in herbaceous peonies stems, and significantly increased the contents of them in the top segment. Correlation analysis showed that the breaking force of the top segment of peonies' stems was positively correlated with the ratio of water insoluble pectin to water soluble pectin (R = 0.673) as well as lignin contents (R = 0.926) after calcium applications. PMID:22606005

Li, Chengzhong; Tao, Jun; Zhao, Daqiu; You, Chao; Ge, Jintao



Intracellular Ionized Calcium.  

National Technical Information Service (NTIS)

Measurement of intracellular ionized calcium concentration (Ca2+) in living cells is of considerable interest to investigators over a broad range of cell biology. Calcium has an important role in a number of cellular functions and, perhaps most interestin...

C. H. June P. S. Rabinovitch



Calcium absorption and achlorhydria  

Microsoft Academic Search

Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium

Robert R. Recker



Calcium and bones  


... body gets the calcium it needs through the food you eat. If you do not get enough calcium in your diet or if your body does not absorb enough, your bones can get weak or not grow properly. Bone density refers to how much calcium and other types ...


Pharmacology of Calcium Antagonists  

Microsoft Academic Search

Although the calcium antagonists verapamil, ni\\\\~{} fedipine, diltiazem and bepridil are structurally diverse, they share, to a variable extent, several pharmacologic properties. These effects are preQ sumably the result of dose-related inhibition of transmembrane calcium ion flux through the slow channel. In diseased tissue, other routes of calcium entry may also be inhibited, and intracellular sites of action also are

Arnold Schwartz; M. Abdul Matus; Joseph Balwierczak; David A. Lathrop



Hyperuricosuric calcium oxalate nephrolithiasis  

Microsoft Academic Search

Many investigators have observed that renal calcium stones may be associated with uric acid disorders. Prien and Prien [1] noted that patients with gout who had stone disease frequently passed stones which contained or were composed of calcium oxalate. Gutman [2] also observed a high frequency of calcium oxalate stones in patients who had gout; and he called attention to

Fredric L Coe



Castable Calcium Aluminate Refractory.  

National Technical Information Service (NTIS)

A castable calcium aluminate refractory having a lower Al2O3 content, which is highly resistant to hot reducing atmospheres, is disclosed. It consists of 15-30% of approximately 85%-325 Tyler mesh calcium aluminate admixed with 85-70% of coarser calcium a...

L. Y. Sadler



[Testicular toxicity of allyl chloride].  


In this study, 124 mg/kg of allyl chloride (one-fifth of LD50) was administered to mice by a single subcutaneous injection and its effects on the male reproductive system were evaluated at 4 days, 9 days, 14 days, 22 days and 39 days after treatment. Allyl chloride decreased the weight of the testes, reduced the numbers of spermatid and sperm, and increased the frequency of the morphologically abnormal sperm without any sign of general influence. From these results, allyl chloride was confirmed to be a definite testicular toxicant in mice. Spermatid reduction was already apparent at 4 days after treatment. Therefore, it was found that allyl chloride affected the testis immediately after the injection. Sperm with an abnormal tail (most of them were sperm with a folded tail) increased at the cauda epididymis before the epididymal sperm reduction became apparent. Consequently, it seemed likely that, with its toxic effects on the testis, allyl chloride also affected sperm passing through the epididymis and disturbed their maturation. Spermatid/sperm reduction caused by allyl chloride did not recover and seemed to get worse until 39 days after treatment. The testicular damage caused by allyl chloride was irreversible during this observation period. PMID:9103701

Zhao, M



Fast calcium wave propagation mediated by electrically conducted excitation and boosted by CICR.  


We have investigated synchronization and propagation of calcium oscillations, mediated by gap junctional excitation transmission. For that purpose we used an experimentally based model of normal rat kidney (NRK) cells, electrically coupled in a one-dimensional configuration (linear strand). Fibroblasts such as NRK cells can form an excitable syncytium and generate spontaneous inositol 1,4,5-trisphosphate (IP(3))-mediated intracellular calcium waves, which may spread over a monolayer culture in a coordinated fashion. An intracellular calcium oscillation in a pacemaker cell causes a membrane depolarization from within that cell via calcium-activated chloride channels, leading to an L-type calcium channel-based action potential (AP) in that cell. This AP is then transmitted to the electrically connected neighbor cell, and the calcium inflow during that transmitted AP triggers a calcium wave in that neighbor cell by opening of IP(3) receptor channels, causing calcium-induced calcium release (CICR). In this way the calcium wave of the pacemaker cell is rapidly propagated by the electrically transmitted AP. Propagation of APs in a strand of cells depends on the number of terminal pacemaker cells, the L-type calcium conductance of the cells, and the electrical coupling between the cells. Our results show that the coupling between IP(3)-mediated calcium oscillations and AP firing provides a robust mechanism for fast propagation of activity across a network of cells, which is representative for many other cell types such as gastrointestinal cells, urethral cells, and pacemaker cells in the heart. PMID:18199705

Kusters, J M A M; van Meerwijk, W P M; Ypey, D L; Theuvenet, A P R; Gielen, C C A M



Mechanism of urinary calcium regulation by urinary magnesium and pH.  


Urinary magnesium and pH are known to modulate urinary calcium excretion, but the mechanisms underlying these relationships are unknown. In this study, the data from 17 clinical trials in which urinary magnesium and pH were pharmacologically manipulated were analyzed, and it was found that the change in urinary calcium excretion is directly proportional to the change in magnesium excretion and inversely proportional to the change in urine pH; a regression equation was generated to relate these variables (R(2) = 0.58). For further exploration of these relationships, intravenous calcium chloride, magnesium chloride, or vehicle was administered to rats. Magnesium infusion significantly increased urinary calcium excretion (normalized to urinary creatinine), but calcium infusion did not affect magnesium excretion. Parathyroidectomy did not prevent this magnesium-induced hypercalciuria. The effect of magnesium loading on calciuria was still observed after treatment with furosemide, which disrupts calcium and magnesium absorption in the thick ascending limb, suggesting that the effect may be mediated by the distal nephron. The calcium channel TRPV5, normally present in the distal tubule, was expressed in Xenopus oocytes. Calcium uptake by TRPV5 was directly inhibited by magnesium and low pH. In summary, these data are compatible with the hypothesis that urinary magnesium directly inhibits renal calcium absorption, which can be negated by high luminal pH, and that this regulation likely takes place in the distal tubule. PMID:18448585

Bonny, Olivier; Rubin, Adam; Huang, Chou-Long; Frawley, William H; Pak, Charles Y C; Moe, Orson W



Selective Measurement of Calcium and Sodium Ion Conductance Using Sub-Micropipette Probes with Ion Filters  

NASA Astrophysics Data System (ADS)

Selective ion currents in aqueous calcium chloride and sodium chloride solutions with concentrations of up to 1.0 M were observed with sub-micropipettes in which poly(vinyl chloride) (PVC) films containing ionophores selectively filtered cations. Calcium bis[4-(1,1,3,3-tetramethyl butyl)phenyl] phosphate (HDOPP-Ca) and bis[(12-crown-4)methyl]-2-dodecyl-2-methylmalonate [bis(12-crown-4)] were used as the ionophores to filter calcium and sodium ions, respectively. The selective ion current was observed using a low-current detection system developed from scanning tunneling microscopy. The approximate linear relationship between the ion concentration and ion current suggests that the sub-micropipette probe can be used to detect the intracellular local concentration of a specific ion up to 1.0 M.

Deng, Xiao Long; Takami, Tomohide; Son, Jong Wan; Kawai, Tomoji; Park, Bae Ho



Studies Update Vinyl Chloride Hazards.  

ERIC Educational Resources Information Center

Extensive study affirms that vinyl chloride is a potent animal carcinogen. Epidemiological studies show elevated rates of human cancers in association with extended contact with the compound. (Author/RE)

Rawls, Rebecca



Actin assembly in electropermeabilized neutrophils: role of intracellular calcium  

PubMed Central

Assembly of microfilaments involves the conversion of actin from the monomeric (G) to the filamentous (F) form. The exact sequence of events responsible for this conversion is yet to be defined and, in particular, the role of calcium remains unclear. Intact and electropermeabilized human neutrophils were used to assess more directly the role of cytosolic calcium [( Ca2+]i) in actin assembly. Staining with 7-nitrobenz-2-oxa-1,3-diazole-phallacidin and right angle light scattering were used to monitor the formation of F-actin. Though addition of Ca2+ ionophores can be known to induce actin assembly, the following observations suggest that an increased [Ca2+]i is not directly responsible for receptor-induced actin polymerization: (a) intact cells in Ca2(+)-free medium, depleted of internal Ca2+ by addition of ionophore, responded to the formyl peptide fMLP with actin assembly despite the absence of changes in [Ca2+]i, assessed with Indo- 1; (b) fMLP induced a significant increase in F-actin content in permeabilized cells equilibrated with medium containing 0.1 microM free Ca2+, buffered with up to 10 mM EGTA; (c) increasing [Ca2+]i beyond the resting level by direct addition of CaCl2 to permeabilized cells resulted in actin disassembly. Conversely, lowering [Ca2+]i resulted in spontaneous actin assembly. To reconcile these findings with the actin- polymerizing effects of Ca2+ ionophores, we investigated whether A23187 and ionomycin induced actin assembly by a mechanism independent of, or secondary to the increase in [Ca2+]i. We found that the ionophore- induced actin assembly was completely inhibited by the leukotriene B4 (LTB4) antagonist LY-223982, implying that the ionophore effect was secondary to LTB4 formation, possibly by stimulation of phospholipase A2. We conclude that actin assembly is not mediated by an increase in [Ca2+]i, but rather that elevated [Ca2+]i facilitates actin disassembly, an effect possibly mediated by Ca2(+)-sensitive actin filament-severing proteins such as gelsolin. Sequential actin assembly and disassembly may be necessary for functions such as chemotaxis.



Effect of Tamm-Horsfall protein on calcium oxalate precipitation.  


The effect of Tamm-Horsfall protein isolated from urine of healthy subjects on calcium oxalate precipitation was studied in model systems of precipitation. The study was performed using following conditions: concentrations of calcium chloride 10 mmol/l, sodium chloride 150 mmol/l, oxalic acid 300 mumol/l; pH 6.0, and temperature 310 K. The concentration of Tamm-Horsfall protein varied between 1-10 mg/l. The kinetics of calcium oxalate precipitation was observed by measuring the number and volume of particles in the suspension, and the precipitate composition by an optic microscope. In all the studied systems, the precipitate morphology corresponded to pure calcium oxalate monohydrate. Tamm-Horsfall protein was found to inhibit the growth of calcium oxalate monohydrate crystals and stimulate their aggregation in the given experimental conditions. Both effects were enhanced by increase in the concentrations of Tamm-Horsfall protein and were most pronounced at the concentration of Tamm-Horsfall protein of 10 mg/l. PMID:8608191

Benkovi?, J; Furedi-Milhofer, H; Hlady, V; Cvoris?ec, D; Stavljeni?-Rukavina, A



Increased Chloride Conductance As the Proximate Cause of Hydrogen Ion Concentration Effects in Aplysia Neurons  

PubMed Central

A fall in extracellular pH increased membrane conductance of the giant cell in the abdominal ganglion of Aplysia californica. Chloride conductance was trebled whereas potassium conductance was increased by 50%. Half the giant cells were hyperpolarized (28 mv) and half were depolarized (310 mv) by lowering the pH. The hyperpolarizing response always became a depolarizing response in half-chloride solutions. When internal chloride was increased electrophoretically, the hyperpolarization was either decreased or changed to depolarization. The depolarizing response was reduced or became a hyperpolarizing response after soaking the cell in 10.0 mM chloride, artificial seawater solution for 1 hr. Depolarization was unaffected when either external sodium, calcium, or magnesium was omitted. A glass micropipette having an organic liquid chloride ion exchanger in its tip was used to measure intracellular chloride activity in 14 giant cells; 7 had values of 27.7 1.8 mM (SEM) and 7 others 40.7 1.5 mM. Three of the first group were hyperpolarized when pH was lowered and three of the second group were depolarized. In all six cells, these changes of membrane potential were in the direction of the chloride equilibrium potential. Intracellular potassium activity was measured by means of a potassium ion exchanger microelectrode.

Brown, A. M.; Walker, J. L.; Sutton, R. B.



Performance of Anionic Polymers as Precipitation Inhibitors for Calcium Phosphonates: The Influence of Cationic Polyelectrolytes  

Microsoft Academic Search

This paper addresses the precipitation of calcium salts of phosphonates (i.e., hydroxyethylidine 1,1 -diphosphonic acid, HEDP;\\u000a aminotri(methylene phosphonic acid), AMP; 2-phosphono-butane 1,2,4-tricarboxylic acid, PBTC) at pH 8.50 and 50C. The aim\\u000a of the study was to investigate the role of cationic polyelectrolytes (i.e., poly(diallyldimethyl ammonium chloride), Poly-E\\u000a and poly(acrylamide:2-(acrolyloxy)ethyltrimethyl ammonium chloride), Poly-F) on the performance of several anionic calcium\\u000a phosphonate

Zahid Amjad; Robert Zuhl; Jennifer Thomas-Wohlever


Stretch-activated calcium channels relay fast calcium waves propagated by calcium-induced calcium influx.  


For nearly 30 years, fast calcium waves have been attributed to a regenerative process propagated by CICR (calcium-induced calcium release) from the endoplasmic reticulum. Here, I propose a model containing a new subclass of fast calcium waves which is propagated by CICI (calcium-induced calcium influx) through the plasma membrane. They are called fast CICI waves. These move at the order of 100 to 1000 microm/s (at 20 degrees C), rather than the order of 3 to 30 microm/s found for CICR. Moreover, in this proposed subclass, the calcium influx which drives calcium waves is relayed by stretch-activated calcium channels. This model is based upon reports from approx. 60 various systems. In seven of these reports, calcium waves were imaged, and, in five of these, evidence was presented that these waves were regenerated by CICI. Much of this model involves waves that move along functioning flagella and cilia. In these systems, waves of local calcium influx are thought to cause waves of local contraction by inducing the sliding of dynein or of kinesin past tubulin microtubules. Other cells which are reported to exhibit waves, which move at speeds in the fast CICI range, include ones from a dozen protozoa, three polychaete worms, three molluscs, a bryozoan, two sea urchins, one arthropod, four insects, Amphioxus, frogs, two fish and a vascular plant (Equisetum), together with numerous healthy, as well as cancerous, mammalian cells, including ones from human. In two of these systems, very gentle local mechanical stimulation is reported to initiate waves. In these non-flagellar systems, the calcium influxes are thought to speed the sliding of actinomyosin filaments past each other. Finally, I propose that this mechanochemical model could be tested by seeing if gentle mechanical stimulation induces waves in more of these systems and, more importantly, by imaging the predicted calcium waves in more of them. PMID:17302561

Jaffe, Lionel F



Heat and mass transfer in porous spherical pellets of CaCl 2 for solar refrigeration  

Microsoft Academic Search

An analysis of heat and mass transfer in porous spherical pellets with vapour absorption\\/desorption is presented. The size, shape and thermophysical properties of the pellet is assumed invariant with time, and the volume reaction model is utilised. The temperature of the solid and vapour phases are assumed to be the same at any location. The resulting partial differential equations for

S. O Enibe; O. C Iloeje



Effects of Inclusions in HSLA Carbon Steel on Pitting Corrosion in CaCl2  

SciTech Connect

Susceptibility of high strength low alloy steel to localized corrosion was studied in 6.7 M CaCl{sub 2} for oil and natural gas drilling applications. Results of the immersion and electrochemical experiments showed that the steel is susceptible to pitting corrosion. Optical microscopy investigations of the polished samples revealed that 10% of the surface area was occupied by defects in the form of pits. The energy dispersive X-ray (EDX) and wavelength dispersive X-ray (WDX) chemical analyses revealed higher concentrations of Mn and S compared to the metal matrix in defected areas. These areas served as the sites for development of corrosion pits during both immersion and electrochemical experiments. The fatigue results of the corroded samples indicate that if the pit was the most significant defect, the fatigue crack initiated and propagated at this site.

M. Ziomek-Moroz; S. Bullard; K. Rozman; J.J. Kruzic



Contribution of calcium oxalate to soil-exchangeable calcium  

USGS Publications Warehouse

Acid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypothesized that the highly insoluble biomineral Ca oxalate might represent an additional soil Ca pool that is not detected in standard measures of soil-exchangeable Ca. We asked whether several standard method extractants for soil-exchangeable Ca could also access Ca held in Ca oxalate crystals using spike recovery tests in both pure solutions and soil extractions. In solutions of the extractants ammonium chloride, ammonium acetate, and barium chloride, we observed 2% to 104% dissolution of Ca oxalate crystals, with dissolution increasing with both solution molarity and ionic potential of cation extractant. In spike recovery tests using a low-Ca soil, we estimate that 1 M ammonium acetate extraction dissolved sufficient Ca oxalate to contribute an additional 52% to standard measurements of soil-exchangeable Ca. However, in a high-Ca soil, the amount of Ca oxalate spike that would dissolve in 1 M ammonium acetate extraction was difficult to detect against the large pool of exchangeable Ca. We conclude that Ca oxalate can contribute substantially to standard estimates of soil-exchangeable Ca in acid forest soils with low soil-exchangeable Ca. Consequently, measures of exchangeable Ca are unlikely to fully resolve discrepancies in ecosystem Ca mass balance unless the contribution of Ca oxalate to exchangeable Ca is also assessed.

Dauer, Jenny M.; Perakis, Steven S.



Impact of sodium polyacrylate on the amorphous calcium carbonate formation from supersaturated solution.  


A detailed in situ scattering study has been carried out on the formation of amorphous calcium carbonate (ACC) particles modulated by the presence of small amounts of sodium polyacrylate chains. The work is aiming at an insight into the modulation of ACC formation by means of two polyacrylate samples differing in their molecular weight by a factor of 50. The ACC formation process was initiated by an in situ generation of CO(3)(2-) ions via hydrolysis of 10 mM dimethylcarbonate in the presence of 10 mM CaCl(2). Analysis of the formation process by means of time-resolved small-angle X-ray and light scattering in the absence of any additives provided evidence for a monomer addition mechanism for the growth of ACC particles. ACC formation under these conditions sets in after a lag-period of some 350 s. In the presence of sodium polyacrylate chains, calcium polyacrylate aggregates are formed during the lag-period, succeeded by a modulated ACC growth in a second step. The presence of anionic polyacrylate chains changed the shape of the growing particles toward loose and less homogeneous entities. In the case of low amounts (1.5-7.5 mg/L) of the long chain additive with 97 kDa, the size of the aggregates is comparable to the size of the successively formed hybrid particles. No variation of the lag-period has been observed in this case. Use of the short chain additive with 2 kDa enabled increase of the additive concentration up to 100 mg/L and resulted in a significant increase of the lag-period. This fact, together with the finding that the resulting hybrid particles remained stable in the latter case, identified short chain sodium polyacrylates as more efficient modulators than long chain polyacrylates. PMID:22256962

Liu, J; Pancera, S; Boyko, V; Gummel, J; Nayuk, R; Huber, K




SciTech Connect

Testing was performed to determine the chloride (Cl-) removal capabilities of the Savannah River National Laboratory (SRNL) designed and built Cl- washing equipment intended for HB-Line installation. The equipment to be deployed was tested using a cerium oxide (CeO2) based simulant in place of the 3013 plutonium oxide (PuO2) material. Two different simulant mixtures were included in this testing -- one having higher Cl- content than the other. The higher Cl- simulant was based on K-Area Interim Surveillance Inspection Program (KIS) material with Cl- content approximately equal to 70,000 ppm. The lower Cl- level simulant was comparable to KIS material containing approximately 8,000-ppm Cl- content. The performance testing results indicate that the washer is capable of reducing the Cl- content of both surrogates to below 200 ppm with three 1/2-liter washes of 0.1M sodium hydroxide (NaOH) solution. Larger wash volumes were used with similar results - all of the prescribed test parameters consistently reduced the Cl- content of the surrogate to a value below 200 ppm Cl- in the final washed surrogate material. The washer uses a 20-micron filter to retain the surrogate solids. Tests showed that 0.16-0.41% of the insoluble fraction of the starting mass passed through the 20-micron filter. The solids retention performance indicates that the fissile masses passing through the 20-micron filter should not exceed the waste acceptance criteria for discard in grout to TRU waste. It is recommended that additional testing be pursued for further verification and optimization purposes. It is likely that wash volumes smaller than those tested could still reduce the Cl- values to acceptable levels. Along with reduced wash volumes, reuse of the third wash volume (in the next run processed) should be tested as a wash solution minimization plan. A 67% reduction in the number of grouted paint pails could be realized if wash solution minimization testing returned acceptable results.

Coughlin, J; David Best, D; Robert Pierce, R



Biomimetic synthesis of calcium-deficient hydroxyapatite in a natural hydrogel  

Microsoft Academic Search

A novel composite material consisting of calcium-deficient hydroxyapatite (CdHAP) biomimetically deposited in a bacterial cellulose hydrogel was synthesized and characterized. Cellulose produced by Gluconacetobacter hansenii was purified and sequentially incubated in solutions of calcium chloride followed by sodium phosphate dibasic. A substantial amount of apatite (5090% of total dry weight) was homogeneously incorporated throughout the hydrogel after this treatment. X-ray

Stacy A. Hutchens; Roberto S. Benson; Barbara R. Evans; Hugh M. ONeill; Claudia J. Rawn




Microsoft Academic Search

A method of impregnating whole corn grain to meet the nitrogen and mineral reqt;irements of growing-finishing lambs was developed. Several compounds were compared as calcium (Ca), potas- sium (K) and sulfur (S) sources based on solubility in a urea solution. A laboratory study was used to evaluate two urea-mineral solutions containing urea, calcium chloride, potassium acetate and sodium thiosulfate. The

L. K. Koeln; K. E. Webb; J. P. Fontenot



Electro-osmotic techniques for removal of chloride from concrete and for emplacement of concrete sealants  

NASA Astrophysics Data System (ADS)

Chloride ion from bridge deck concrete can be removed by application of a direct current potential between bridge reinforcing steel (-) and a copper screen (+) conductor on the bridge surface. Soaring prices of all types of energy would make removal of all chloride prohibitatively expensive. The importance of verification of all electrical connections prior to the treatment is emphasized by the demonstration of concrete cracking when the steel was made a positive instead of a negative electrode. Data on effectiveness of calcium nitrite corrosion inhibitor added to the concrete overlay placed on electrotreated concrete is not extensive due to accidental damage to the test slabs.

Jayaprakash, G. P.; Bukovatz, J. E.; Ramamurti, K.; Gilliland, W. J.



Calcium-43 chemical shift and electric field gradient tensor interplay: a sensitive probe of structure, polymorphism, and hydration.  


Calcium is the 5th most abundant element on earth, and is found in numerous biological tissues, proteins, materials, and increasingly in catalysts. However, due to a number of unfavourable nuclear properties, such as a low magnetogyric ratio, very low natural abundance, and its nuclear electric quadrupole moment, development of solid-state (43)Ca NMR has been constrained relative to similar nuclides. In this study, 12 commonly-available calcium compounds are analyzed via(43)Ca solid-state NMR and the information which may be obtained by the measurement of both the (43)Ca electric field gradient (EFG) and chemical shift tensors (the latter of which are extremely rare with only a handful of literature examples) is discussed. Combined with density functional theory (DFT) computations, this 'tensor interplay' is, for the first time for (43)Ca, illustrated to be diagnostic in distinguishing polymorphs (e.g., calcium formate), and the degree of hydration (e.g., CaCl22H2O and calcium tartrate tetrahydrate). For Ca(OH)2, we outline the first example of (1)H to (43)Ca cross-polarization on a sample at natural abundance in (43)Ca. Using prior knowledge of the relationship between the isotropic calcium chemical shift and the calcium quadrupolar coupling constant (CQ) with coordination number, we postulate the coordination number in a sample of calcium levulinate dihydrate, which does not have a known crystal structure. Natural samples of CaCO3 (aragonite polymorph) are used to show that the synthetic structure is present in nature. Gauge-including projector augmented-wave (GIPAW) DFT computations using accepted crystal structures for many of these systems generally result in calculated NMR tensor parameters which are in very good agreement with the experimental observations. This combination of (43)Ca NMR measurements with GIPAW DFT ultimately allows us to establish clear correlations between various solid-state (43)Ca NMR observables and selected structural parameters, such as unit cell dimensions and average Ca-O bond distances. PMID:24874995

Widdifield, Cory M; Moudrakovski, Igor; Bryce, David L



Effects of calcium ions on solubility and aggregation behavior of an anionic sulfonate gemini surfactant in aqueous solutions.  


Effects of calcium ions on the solubility and aggregation behavior of an anionic sulfonate gemini surfactant 1,3-bis(N-dodecyl-N-propylsulfonate sodium)-propane (12-3-12(SO(3))(2)) have been studied in aqueous solution. Compared with single-chain surfactant sodium dodecylsulfate, 12-3-12(SO(3))(2) shows much better performance to the hardness tolerance with calcium ions. Moreover aggregates of the Ca(2+)/12-3-12(SO(3))(2) complexes in clear solutions influence the morphologies of the precipitates. At 12-3-12(SO(3))(2) concentrations lower than 1.5 mM, the small spherical micelles of Ca(2+)/12-3-12(SO(3))(2) in clear solutions generate precipitates of solid particles owing to complexation of surfactant monomers with Ca(2+). At 12-3-12(SO(3))(2) concentrations higher than 1.5mM, the Ca(2+)/12-3-12(SO(3))(2) complexes transform into large compact spherical aggregates and then into long wormlike micelles. These large aggregates are well dispersed in aqueous solutions and efficiently complex calcium ions. In particular, long wormlike micelles are entangled with each other at 100.0 mM CaCl(2) and 100.0 mM 12-3-12(SO(3))(2) exhibiting viscoelastic properties. In addition, the stacking of long wormlike micelles produces precipitates with ordered fibrillar structures. This work reveals that such anionic sulfonate gemini surfactants are better candidates than single-chain surfactants in applications with high hardness levels, and the ordered aggregate structures may have potential applications in materials science. PMID:22682325

Yu, Defeng; Wang, Yingxiong; Zhang, Jian; Tian, Maozhang; Han, Yuchun; Wang, Yilin



The Obesity-Related Peptide Leptin Sensitizes Cardiac Mitochondria to Calcium-Induced Permeability Transition Pore Opening and Apoptosis  

PubMed Central

The obesity-related 16 kDa peptide leptin is synthesized primarily in white adipocytes although its production has been reported in other tissues including the heart. There is emerging evidence that leptin may contribute to cardiac pathology especially that related to myocardial remodelling and heart failure. In view of the importance of mitochondria to these processes, the goal of the present study is to determine the effect of leptin on mitochondria permeability transition pore opening and the potential consequence in terms of development of apoptosis. Experiments were performed using neonatal rat ventricular myocytes exposed to 3.1 nM (50 ng/ml) leptin for 24 hours. Mitochondrial transition pore opening was analyzed as the capacity of mitochondria to retain the dye calcein-AM in presence of 200 M CaCl2. Leptin significantly increased pore opening although the effect was markedly more pronounced in digitonin-permeabilized myocytes in the presence of calcium with both effects prevented by the transition pore inhibitor sanglifehrin A. These effects were associated with increased apoptosis as evidenced by increased TUNEL staining and caspase 3 activity, both of which were prevented by the transition pore inhibitor sanglifehrin A. Leptin enhanced Stat3 activation whereas a Stat 3 inhibitor peptide prevented leptin-induced mitochondrial transition pore opening as well as the hypertrophic and pro-apoptotic effects of the peptide. Inhibition of the RhoA/ROCK pathway prevented the hypertrophic response to leptin but had no effect on increased pore opening following leptin administration. We conclude that leptin can enhance calcium-mediated, Stat3-dependent pro-apoptotic effects as a result of increased mitochondrial transition pore opening and independently of its hypertrophic actions. Leptin may therefore contribute to mitochondrial dysfunction and the development of apoptosis in the diseased myocardium particularly under conditions of excessive intracellular calcium accumulation.

Martinez-Abundis, Eduardo; Rajapurohitam, Venkatesh; Haist, James V.; Gan, Xiaohong T.; Karmazyn, Morris



Influence of water hardness and sulfate on the acute toxicity of chloride to sensitive freshwater invertebrates.  


Total dissolved solids (TDS) represent the sum of all common ions (e.g., Na, K, Ca, Mg, chloride, sulfate, and bicarbonate) in freshwater. Currently, no federal water quality criteria exist for the protection of aquatic life for TDS, but because the constituents that constitute TDS are variable, the development of aquatic life criteria for specific ions is more practical than development of aquatic life criteria for TDS. Chloride is one such ion for which aquatic life criteria exist; however, the current aquatic life criteria dataset for chloride is more than 20 years old. Therefore, additional toxicity tests were conducted in the current study to confirm the acute toxicity of chloride to several potentially sensitive invertebrates: water flea (Ceriodaphnia dubia), fingernail clams (Sphaerium simile and Musculium transversum), snail (Gyraulus parvus), and worm (Tubifex tubifex), and determine the extent to which hardness and sulfate modify chloride toxicity. The results indicated a significant ameliorating effect of water hardness (calcium and magnesium) on chloride toxicity for all species tested except the snail; for example, the 48-h chloride median lethal concentration (LC50) for C. dubia at 50?mg/L hardness (977?mg Cl(-) /L) was half that at 800?mg/L hardness (1,836?mg Cl(-) /L). Conversely, sulfate over the range of 25 to 600?mg/L exerted a negligible effect on chloride toxicity to C. dubia. Rank order of LC50 values for chloride at a given water hardness was in the order (lowest to highest): S. simile?

Soucek, David J; Linton, Tyler K; Tarr, Christopher D; Dickinson, Amy; Wickramanayake, Nilesh; Delos, Charles G; Cruz, Luis A



Calcium magnesium acetate production and cost reduction  

SciTech Connect

The New York State Energy Research and Development Authority (Energy Authority), Consolidated Edison Company of New York, Inc. (ConEd), the New York State Department of Transportation (NYSDOT), the New York State Thruway Authority (NYSTA), Chevron Chemical Company, the National Corn Growers Association (NCGA), and the Massachusetts Department of Public Works (MDPW) sponsored a research program to develop technology capable of producing Calcium Magnesium Acetate (CMA), an alternative road deicer, at a quality and cost which will allow its increased use. The objectives of this program were to determine the feasibility of: (1) producing CMA from regionally available waste and low grade organic feedstocks via biochemical engineering technologies; (2) operating the fermentation at concentrated product levels to reduce energy requirements and minimize drying process costs; (3) using this production approach to produce an environmentally acceptable CMA product; and (4) using and adapting an existing facility for a CMA commercial demonstration plant. The experimental program included:(1) selection of microorganisms for their ability to grow in the absence of sodium chloride and to tolerate high concentrations of calcium, magnesium, and acetate ions; (2) analysis of waste feedstocks for their potential conversion to acetate; (3) analysis of waste organic material for impurities in CMA that could carry over into the environment; (4) batch experiments to determine pH tolerance, growth in the absence of sodium chloride (NaCl), tolerance to magnesium, calcium and acetate ions, effect of substrate concentration, acid distribution, and acid production; and (5) semi-continuous laboratory scale anaerobic digestion experiments to determine loading rates, conversion efficiencies, and other design data. 67 refs., 33 figs., 66 tabs.

Leuschner, A.P.



Studies on the yield and gel strength of agar from Gracilaria domingensis Sonder ex Kuetzing (Gracilariales, Rhodophyta) following the addition of calcium  

Microsoft Academic Search

Studies were carried out on the seasonal variation in yield and gel strength of agar from Gacilaria domingensis with and without the addition of calcium chloride. Extraction was done with and without treatment with 1% hydrochloric acid. The results showed an increase in yield and gel strength when an alkaline solution of calcium was used, but the gel strength was

Muttutamby Durairatnam; Tahise Maria Brito Medeiros; Albanisa Maria de Sena



Calcium Nutrition in Adolescence  

Microsoft Academic Search

Adolescence is an important period of nutritional vulnerability due to increased dietary requirements for growth and development and special dietary habits. Calcium needs are elevated as a result of the intensive bone and muscular development and thus adequate calcium intake during growth is extremely important to reach the optimum peak bone mass and to protect against osteoporosis in the adult

Marta Mesas; Isabel Seiquer; M. Pilar Navarro



Calcium signaling in neurodegeneration  

PubMed Central

Calcium is a key signaling ion involved in many different intracellular and extracellular processes ranging from synaptic activity to cell-cell communication and adhesion. The exact definition at the molecular level of the versatility of this ion has made overwhelming progress in the past several years and has been extensively reviewed. In the brain, calcium is fundamental in the control of synaptic activity and memory formation, a process that leads to the activation of specific calcium-dependent signal transduction pathways and implicates key protein effectors, such as CaMKs, MAPK/ERKs, and CREB. Properly controlled homeostasis of calcium signaling not only supports normal brain physiology but also maintains neuronal integrity and long-term cell survival. Emerging knowledge indicates that calcium homeostasis is not only critical for cell physiology and health, but also, when deregulated, can lead to neurodegeneration via complex and diverse mechanisms involved in selective neuronal impairments and death. The identification of several modulators of calcium homeostasis, such as presenilins and CALHM1, as potential factors involved in the pathogenesis of Alzheimer's disease, provides strong support for a role of calcium in neurodegeneration. These observations represent an important step towards understanding the molecular mechanisms of calcium signaling disturbances observed in different brain diseases such as Alzheimer's, Parkinson's, and Huntington's diseases.

Marambaud, Philippe; Dreses-Werringloer, Ute; Vingtdeux, Valerie



Calcium hydroxyapatite fillers.  


Calcium hydroxyapatite fillers have unique advantages over other fillers in regards to duration of action and volume of product required for augmentation, especially in the midface and lower face. In this article, we describe our experience with calcium hydroxyapatite fillers and compare them with other available filler products. PMID:22205523

Tansavatdi, Kristina; Mangat, Devinder S



High Blood Calcium (Hypercalcemia)  


... glands in your neck) secrete a hormone called parathyroid hormone (Pth). Pth helps your bones release calcium into ... together, Pth and vitamin D, along with other hormones and minerals, help move calcium in or ... or more of the parathyroid glands produces too much Pth. this, in turn, ...


Calcium stone disease: a multiform reality  

Microsoft Academic Search

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate.

Alberto Trinchieri; Chiara Castelnuovo; Renata Lizzano; Giampaolo Zanetti



The effects of calcium on potassium transport in ferret red cells.  

PubMed Central

1. The effects of changes in the concentration of intracellular calcium on potassium transport were investigated in ferret red cells. Bumetanide was used to divide potassium transport into three components: total, bumetanide sensitive and bumetanide resistant. The bumetanide-sensitive component is equivalent to sodium-potassium-chloride co-transport. 2. Internal calcium concentration was controlled with the ionophore A23187 which was present throughout the experiments. 3. Changes in internal ionized calcium over the range 5 X 10(-10) M to 7 X 10(-7) M did not affect any component of potassium uptake. 4. Increasing the internal ionized calcium concentration above 10(-6) M stimulated bumetanide-resistant potassium transport. Half-maximal stimulation of this system was achieved with 3 X 10(-6) M-internal calcium. The system spontaneously inactivated after the initial activation by calcium and ionophore. Transport was inhibited by 1 mM-quinine. 5. Increasing the internal ionized calcium concentration to 10(-5) M had no effect on bumetanide-sensitive transport. 6. Concentrations of intracellular ionized calcium above 10(-5) M inhibited all three components of transport. Inhibition of the bumetanide-sensitive component was only slightly reversed when internal calcium concentration was reduced to normal. 7. Physiological changes in internal ionized calcium concentration do not affect sodium-potassium-chloride co-transport in ferret red cells. Very high concentrations of calcium inhibit transport, probably by an indirect mechanism. 8. In the course of the experiments the concentration of ionized intracellular magnesium in oxygenated ferret red cells was found to be about 0.65 mM.

Flatman, P W



Calcium ion binding to a soil fulvic acid using a donnan potential model  

USGS Publications Warehouse

Calcium ion binding to a soil fulvic acid (Armadale Bh Horizon) was evaluated over a range of calcium ion concentrations, from pH 3.8 to 7.3, using potentiometric titrations and calcium ion electrode measurements. Fulvic acid concentration was constant (100 milligrams per liter) and calcium ion concentration varied up to 8 X 10-4 moles per liter. Experiments discussed here included: (1) titrations of fulvic acid-calcium ion containing solutions with sodium hydroxide; and (2) titrations of fully neutralized fulvic acid with calcium chloride solutions. Apparent binding constants (expressed as the logarithm of the value, log ??app) vary with solution pH, calcium ion concentration, degree of acid dissociation, and ionic strength (from log ??app = 2.5 to 3.9) and are similar to those reported by others. Fulvic acid charge, and the associated Donnan Potential, influences calcium ion-fulvic acid ion pair formation. A Donnan Potential corrrection term allowed calculation of intrinsic calcium ion-fulvic acid binding constants. Intrinsic binding constants vary from 1.2 to 2.5 (the average value is about log??= 1.6) and are similar to, but somewhat higher than, stability constants for calcium ion-carboxylic acid monodentate complexes. ?? by Oldenbourg Wissenschaftsverlag, Mu??nchen.

Marinsky, J. A.; Mathuthu, A.; Ephraim, J. H.; Reddy, M. M.



Alternative technique for calcium phosphate coating on titanium alloy implants.  


As an alternative technique for calcium phosphate coating on titanium alloys, we propose to functionalize the metal surface with anionic bath containing chlorides of palladium or silver as activators. This new deposition route has several advantages such as controlled conditions, applicability to complex shapes, no adverse effect of heating, and cost effectiveness. A mixture of hydroxyapatite and calcium phosphate hydrate is deposited on the surface of Ti-6Al-4V. Calcium phosphate coating is built faster compared with the one by Simulated Body Fluid. Cell morphology and density are comparable to the control one; and the results prove no toxic compound is released into the medium during the previous seven days of immersion. Moreover, the cell viability is comparable with cells cultivated with the virgin medium. These experimental treatments allowed producing cytocompatible materials potentially applicable to manufacture implantable devices for orthopedic and oral surgeries. PMID:24646569

Le, Van Quang; Pourroy, Genevive; Cochis, Andrea; Rimondini, Lia; Abdel-Fattah, Wafa I; Mohammed, Hadeer I; Carrad, Adele



Sodium Chloride Toxicity in Dogs.  

National Technical Information Service (NTIS)

The objective of the research was to determine whether consistent, significant differences in response to life span dietary sodium chloride levels occur in dogs, and, if so, the influence of sex and genetics and exploration of the significance in the occu...

J. B. Youmans



Chloride thresholds in marine concrete  

Microsoft Academic Search

This paper reports results from an ongoing study of the performance of fly ash concrete in marine exposure. Reinforced concrete specimens exposed to tidal conditions were retrieved at ages ranging from 1 to 4 years. Steel reinforcement mass losses are compared with chloride contents at the location of the bar for concrete specimens of various strength grades and with a

Michael Thomas



The Mechanochemical Self-Propagating Reaction between Hexachlorobenzene and Calcium Hydride  

NASA Astrophysics Data System (ADS)

We report on studies of the solid state reaction between hexachlorobenzene and calcium hydride carried out by high-energy ball milling. The transformation behavior depends on the intensity of the mechanical energy transferred to the reactants at the impact. At lower energy regimes, chemical conversions increase gradually as a function of the milling time and a large excess of calcium hydride was found to favor the reaction rate. Calcium hydride-chloride and benzene are formed as end products. Beyond an impact energy threshold, self-sustaining transformations were observed leading to an instantaneous transformation to hydrogen, graphite, and depending upon the reactant molar ratio, to calcium hydride-chloride or calcium chloride. The sudden increase of the reactor-vial temperature was proportional to the hexachlorobenzene content in the reacting mixture and the total heat evolved was found to be in good agreement with the forecasted reaction enthalpies. The ignition time, i.e., the milling time at which the combustion-like event occurs, was followed as a function of the reactant composition. The incubation period rapidly decreases by increasing the calcium hydride to hexachlorobenzene molar ratio, that is, moving away from the stoichiometric composition at which calcium chloride forms predominantly. Some suggestions concerning the activation energy of the two competing end products were inferred from the mechanochemical yield which has been calculated as the ratio between the moles of reacted hexachlorobenzene divided by the total injected energy dose. Keeping the molar composition constant and modulating the shock power intensity, the self-sustaining reaction takes place only when the same dose of mechanical energy has been supplied to the reacting system, irrespective of the single impact energy.

Mulas, G.; Loiselle, S.; Schiffini, L.; Cocco, G.



Solubility of some alkali and alkaline earth chlorides in water at moderate temperatures  

USGS Publications Warehouse

Solubilities for the binary systems, salt-H2O, of the chlorides of lithium, rubidium, cesium, magnesium, calcium, strontium, and barium from near 0??C to the saturated boiling point are reported. The experimental data and coefficients of an equation for a smoothed curve describing each system are listed in the tables. The data are improvements on those previously reported in the literature, having a precision on the average of ??0.09%.

Clynne, M. A.; Potter, II, R. W.




SciTech Connect

The preparation and properties of a calcium phosphate ceramic wasteform based on the mineral phases apatite and spodiosite are described. This particular ceramic has been found to be an effective host for immobilizing the chloride constituents obtained from the pyrochemical reprocessing of Pu metal. We discuss the crystal phases present in the solids as determined by XRD and the chemical durability of the product in aqueous solution.

Donald, Ian W.; Metcalfe, Brian; Scheele, Randall D.; Strachan, Denis M.