High temperature distillation process with sea water feed decalcification pretreatment

Milk caseins stabilize calcium and phosphate ions and make them available to the neonate. Tryptic digestion of the caseins yields phosphopeptides from their polar N-terminal regions that contain clusters of phosphorylated seryl residues. These phosphoseryl clusters have been hypothesized to be responsible for the interaction between the caseins and calcium phosphate that lead to the formation of casein micelles. The casein phosphopeptides stabilize calcium and phosphate ions through the formation of complexes. The calcium phosphate in these complexes is biologically available for intestinal absorption and remineralization of subsurface lesions in tooth enamel. We have studied the structure of the complexes formed by the casein phosphopeptides with calcium phosphate using a range of physicochemical techniques including x-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and equilibrium binding analyses. The amorphous nature of the calcium phosphate phase was confirmed by two independent methods: x-ray powder diffraction and selected area diffraction. In solution, the ion activity product of a basic amorphous calcium phosphate phase was the only ion product that was a function of bound phosphate independent of pH, consistent with basic amorphous calcium phosphate being the phase stabilized by the casein phosphopeptides. Detailed investigations of calcium and calcium phosphate binding using a library of synthetic homologues and analogues of the casein phosphopeptides have revealed that although the fully phosphorylated seryl-cluster motif is pivotal for the interaction with calcium and phosphate, other factors are also important. In particular, calcium binding and calcium phosphate stabilization by the peptides was influenced by peptide net charge, length, and sequence.

Effect of calcium ions on oxygen equilibrium of hemocyanin of asiatic horseshoe crab Tachypleus tridentatus

In order to investigate the influence of calcium and strontium ion concentration on human bone marrow stromal cells and their differentiation to osteoblasts, different cell culture media have been used. Even though this study does not contain a bone substitute material, the reason for this study was the decrease of cation concentration by many biomaterials, due to induced apatite precipitation. As a consequence, the reduced calcium ion concentration is known to affect osteoblastic development. Therefore, the main focus was put on the question, whether an increased strontium concentration (in the range of mM) might be suitable to compensate the lack of calcium ions. The effect of solely strontium ions-with only calcium in the media resulting from fetal calf serum-was investigated. Commercially available calcium-free medium (modified α-MEM) was tested in comparison with media with varied calcium ion concentrations (0.9, 1.8, and 3.6mM), or strontium ion concentration (0.4, 0.9, 1.8, and 3.6mM). In case of calcium, higher concentrations cause increased proliferation, while differentiation was shifted to earlier points of time. Differentiation was increased by solely strontium ions only at 0.4-0.9mM, while proliferation was highest for 0.9-1.8mM. From these results, it can be concluded that strontium is able to compensate a lack of calcium to a certain degree. Thus, in contrast to calcium ion release, a strontium ion release from bone substitute materials might be applicable for stimulation of bone regeneration without influencing the media saturation.

Effect of different salt ions with different concentrations on the stability of carbon dioxide-in-water foam fracturing fluids

ObjectiveThe aim of this study was to evaluate the amount of saliva secreted and calcium, bicarbonate, and phosphate ion concentration in patients receiving antihypertensive for five years or over five years (patient group) and in healthy patients (control group).Material and methodsThe patient or experimental group included 31 subjects who were admitted to a cardiovascular clinic and had been receiving an antihypertensive drug therapy for more than five years. The control group included 31 healthy subjects. The measured amount of saliva was further used to determine the calcium, phosphate and bicarbonate ion concentration values. Calcium and phosphate ions were determined spectrophotometrically, while bicarbonate ions were determined by titration.ResultsA two-way-test (Student's test) was used to compare the values of variables. The amount of excreted saliva was statistically significantly lower in the patient group in non-stimulated (1.739 mL/5 min) and stimulated saliva (3.594 mL/5 min). Calcium ion concentration was statistically significantly lower in patient group in resting saliva (6.143 mg/dL). Bicarbonate and phosphate ion concentration in patient group was statistically significantly higher in non-stimulated (bicarbonate ion = 14.041 mmol/L, phosphate ion = 2.818 μmol/L) and stimulated saliva (bicarbonate ion = 10.872 mmol/L, phosphate ion = 1.454 μmol/L), respectively.ConclusionA reduced amount of saliva and calcium ion concentration indicates the possibility of a higher frequency of hard dental tissue demineralization process. On the contrary, the increase in the phosphate and bicarbonate ion concentration in the patient group affects the regulation of acid-base balance, thus having a preventive effect.

Effect of calcium ion (cross-linker) concentration on porosity, surface morphology and thermal behavior of calcium alginates prepared from algae (Undaria pinnatifida)

BackgroundEven subtle changes in environmental factors can exert behavioral effects on creatures, which may alter interspecific interactions and eventually affect the ecosystem. However, how changes in environmental factors impact complex behaviors regulated by neural processes is largely unknown. The freshwater planarian Dugesia japonica, a free-living flatworm, displays distinct behavioral traits mediated by sensitive perception of environmental cues. Planarians are thus useful organisms for examining interactions between environmental changes and specific behaviors of animals.ResultsHere we found that feeding behavior was suppressed when the concentration of ions in the breeding water was low, while other behaviors were unaffected, resulting in differences in population size. Notably, the decline in feeding behavior was reversed in an ion-concentration-dependent manner soon after the planarians were moved to ion-containing water, which suggests that ions in environmental water rapidly promote feeding behavior in planarians. Moreover, the concentration of ions in the environmental water affected the feeding behavior by modulating the sensitivity of the response to foods. Finally, we found that calcium ions in the aquatic environment were required for the feeding behavior, and exposure to higher levels of calcium ions enhanced the feeding behavior, showing that there was a good correlation between the concentration of calcium ions and the responsiveness of planarians to foods.ConclusionsEnvironmental calcium ions are indispensable for and potentiate the activity level of the feeding behavior of planarians. Our findings suggest that the ions in the aquatic environment profoundly impact the growth and survival of aquatic animals via modulating their neural activities and behaviors.

The fact that the addition of sodium citrate to calcium containing solutions reduces the concentration of ionic calcium is well known. The nature of the combination between calcium and citrate has not been definitely established. It has been sometimes thought that a neutral compound Ca3(citrate)2, exists, but this is not consistent with the evidence that the combination between calcium and citrate is negatively charged. For this reason the frog heart preparation which had been shown to be sensitive to calcium ion changes under controlled conditions was used to assay the calcium ion concentration in solutions of varying total calcium and citrate content. The results of such experiments are shown in the accompanying figure. The experimental points show the concentrations of calcium and citrate present in solutions which are iso-active with corresponding solutions containing no citrate, but containing a certain concentration of calcium ions. Each series of symbols represents physiologically isoactive points. The relationship for a given concentration of calcium ions appears to be linear for the limits within which this technique is accurate, i. e., calcium ion concentrations from 0.3 to 1.2 millimols per liter. This has been found to be true when the total calcium concentration is as high as 30 millimols per liter. These results are consistent with the interpretation that (1) calcium combined with citrate does not affect the amplitude of contraction of the frog heart and (2) that one mol of calcium combines with one mol of citrate to form a calcium citrate compound carrying one negative charge. The straight lines in the figure fit the equation, The same problem has also been studied chemically by equilibrating salt solutions containing citrate with calcium carbonate and calculating the calcium ions from the solubility product constant of the solid phase.

Economical evaluation of Alkhobar Phase two 50 MIGPD at three different mode of operations

To explore the effects of tetramethylpyrazine on the nitric oxide synthase activity and calcium ion concentration in skeletal muscle fiber and decipher the possible mechanisms of anti-muscle atrophy function of tetramethylpyrazine in hindlimb unloading rats. Hindlimb unloading (HLU) rats were used as a muscle atrophy model to study the activity of nitric oxide synthase by colorimetry. The concentration of intracellular calcium ion was measured by laser scanning confocal microscope. A total of 18 female rats were randomly divided into 3 groups: control (CON), hindlimb unloading with water (HLU + W) and hindlimb unloading with tetramethylpyrazine (HLU + Tmp) (n = 6 each). (1) Compared with CON, the activity of nitric oxide synthase decreased by 28% in HLU + W (P < 0.05) and decreased by 46% in HLU + Tmp (P < 0.01). The activity of nitric oxide synthase less decreased in HLU + Tmp than that in HLU + W, but it was not statistically significant (P > 0.05). (2) Compared with CON, the concentrations of intracellular calcium ion in HLU + W and HLU + Tmp increased by 330% and 86% respectively (P < 0.01). Compared with HLU + W, the concentration of intracellular calcium ion decreased by 130% in HLU + Tmp (P < 0.01). The activity of nitric oxide synthase decreases and the concentration of calcium ion increases in hindlimb unloading rats. And tetramethylpyrazine may suppress the calcium ion overloading but not the activity of NOS associated with disuse muscular atrophy.

The presence of calcium sulfate in the process water during the coal flotation greatly influences the recovery and selectivity of the separation. The concentrations of calcium and sulfate ions modify mineral hydrophobicity by altering surface properties resulting in depression or activation of the mineral species. An investigation to evaluate the statistical significance of the effect of the pH and concentration of calcium and sulfate ions on coal flotation was carried out; for this purpose, a 23 factorial design was implemented. A p-value &lt; 0.05 was determined for the effect of calcium and sulfate ion concentrations, indicating that it is statistically significant. The interactions between factors (pH × calcium, pH × sulfate, calcium × sulfate and pH × calcium × sulfate) are also statistically significant, but the interaction between the concentration of calcium and sulfate ions has a notable influence according to the F statistic value. Employing 800 and 1920 mg/L of calcium and sulfate ions as experimental conditions yields a recovery of 90.4% with a concentrate containing 13% ash.

Objective To evaluate the effect of dexmedetomidine on the expression of NR1 subunit-containing NMDA receptors and GluR2 subunit-containing AMPA receptors during hypoxic injury to rat hippocampal neurons. Methods The hippocampal neurons were isolated from Wistar rats within 24 h after birth and divided into 3 groups (n=24 each) using a random number table: control group (group C), hypoxia group (group H) and dexmedetomidine group (group D). The cells were subjected to hypoxia for 6 h to establish the model of neuronal hypoxic injury in H and D groups.In group D, 0.1 μmol/L dexmedetomidine was added at 6 h of hypoxia and neurons were incubated for 3 h, and then the culture medium was replaced with a normal medium and neurons were incubated for 24 h. The neuronal viability was measured by CCK-8 assay, the leakage of LDH was detected, and the leakage rate was calculated.The expression of NR1 subunits-containing NMDA receptors and GluR2 subunits-containing AMPA receptors was detected by Western blot.The concentration of calcium ion in cytoplasm was measured using Fluo-3AM. Results Compared with group C, the neuronal viability was significantly decreased, the LDH leakage rate was increased, the expression of NR1 subunits-containing NMDA receptors in the membrane was up-regulated, the expression of GluR2 subunits-containing AMPA receptors was down-regulated, and the concentration of calcium ion in cytoplasm was increased in H and D groups (P<0.05). Compared with group H, the neuronal viability was significantly increased, the LDH leakage rate was decreased, the expression of NR1 subunits-containing NMDA receptors in the membrane was down-regulated, the expression of GluR2 subunits-containing AMPA receptors was up-regulated, and the concentration of calcium ion in cytoplasm was decreased in group D (P<0.05). Conclusion The mechanism by which dexmedetomidine reduces hypoxic injury to rat hippocampal neurons may be related to inhibiting up-regulation of the expression of NR1 subunits-containing NMDA receptors in the membrane and down-regulation of the expression of GluR2 subunits-containing AMPA receptors. Key words: Dexmedetomidine; Anoxia; Neurons; Receptors, N-methyl-D-aspartate; Receptors, AMPA

The effect of increasing the calcium, magnesium and sodium concentration in gall bladder bile samples from 21 patients with gall stones and nine controls on the in vitro rate of formation of cholesterol microcrystals and numbers of cholesterol microcrystals formed was examined. Addition of these cations to raise the mean maximum concentration of calcium ions to 19.8 mmol/l, of magnesium ions to 20 mmol/l and sodium ions to 998 mmol/l did not trigger nucleation in control bile samples or samples from patients with gall stones. Increasing the mean concentration of calcium ions to 8.6 mmol/l and of sodium to 320 mmol/l increased the numbers of cholesterol monohydrate crystals/0.1 mm3 counted by light polarisation phase contrast microscopy at the time of nucleation in samples from patients with gall stones from a median of 2 (range 1-10) in control portions to 18 (range 2-128) for calcium ions and 10 (range 2-141) for sodium ions (p less than 0.001). Calcium and magnesium ions were more effective than sodium ions, and calcium ions could increase crystal numbers at concentrations found in samples from patients with gall stones, median 4.6 mmol/l (range 2.7-16.9 mmol/l). The concentrations of calcium and magnesium present in bile may therefore influence the rate of development of gall stones.

Integration of native bone into orthopedic devices is a key factor in long-term implant success. The material-tissue interface is generally accepted to consist of a hydroxyapatite layer so bioactive materials that can spontaneously generate this hydroxyapatite layer after implantation may improve patient outcomes. Per the ISO 22317:2014 standard, "Implants for surgery - In vitro evaluation for apatite-forming ability of implant materials," bioactivity performance statements can be assessed by soaking the material in simulated body fluid (SBF) and evaluating the surface for the formation of a hydroxyapatite layer; however, variations in test methods may alter hydroxyapatite formation and result in false-positive assessments. The goal of this study was to identify the effect of SBF formulation on bioactivity assessment. Bioglass® (45S5 and S53P4) and non-bioactive Ti-6Al-4V were exposed to SBF formulations varying in calcium ion and phosphate concentrations as well as supporting ion concentrations. Scanning electron microscopy and X-ray powder diffraction evaluation of the resulting hydroxyapatite layers revealed that SBF enriched with double or quadruple the calcium and phosphate ion concentrations increased hydroxyapatite crystal size and quantity compared to the standard formulation and can induce hydroxyapatite crystallization on surfaces traditionally considered non-bioactive. Altering concentrations of other ions, for example, bicarbonate, changed hydroxyapatite induction time, quantity, and morphology. For studies evaluating the apatite-forming ability of a material to support bioactivity performance statements, test method parameters must be adequately described and controlled. It is unclear if apatite formation after exposure to any of the SBF formulations is representative of an in vivo biological response. The ISO 23317 standard test method should be further developed to provide additional guidance on apatite characterization and interpretation of the results.

WARNING : The light-emitting molecular structures responsible for the chemiluminescence and fluorescence phenomena are not necessarily the same!