Addition Of Calcium Research Articles

Calcium supplementation relieves high-fat diet-induced liver steatosis by reducing energy metabolism and promoting lipolysis

Nonalcoholic fatty liver disease (NAFLD) is a chronic disease affecting the health of many people worldwide. Previous studies have shown that dietary calcium supplementation may alleviate NAFLD, but the underlying mechanism is not clear. In this study investigating the effect of calcium on hepatic lipid metabolism, 8-week-old male C57BL/6J mice were divided into four groups (n = 6): (1) mice given a normal chow containing 0.5% calcium (CN0.5), (2) mice given a normal chow containing 1.2% calcium (CN1.2), (3) mice given a high-fat diet (HFD) containing 0.5% calcium (HFD0.5), and (4) mice fed a HFD containing 1.2% calcium (HFD1.2). To understand the underlying mechanism, cells were treated with oleic acid and palmitic acid to mimic the HFD conditions in vitro. The results showed that calcium alleviated the increase in triglyceride accumulation induced by oleic acid and/or palmitic acid in HepG2, AML12, and primary hepatocyte cells. Our data demonstrated that calcium supplementation alleviated HFD-induced hepatic steatosis through increased liver lipase activity, proving calcium is involved in the regulation of hepatic lipid metabolism. Moreover, calcium also increased the level of glycogen in the liver, and at the same time had the effect of reducing glycolysis and promoting glucose absorption. Calcium addition increased calcium levels in the mitochondria and cytoplasm. Taken together, we concluded that calcium supplementation could relieve HFD-induced hepatic steatosis by changing energy metabolism and lipase activity.

Serum calcium and long-term outcome after ischemic stroke: Results from the China National stroke registry III

Background and aimsSerum calcium abnormality is associated with adverse cardiovascular outcomes, but the effects of serum calcium level on stroke outcomes remain unknown. We aimed to assess the relationship between serum calcium level and 1-year outcomes in patients with acute ischemic stroke and transient ischemic attack. MethodsWe included 9375 stroke patients from the China National Stroke Registry III for analysis. Participants were divided into 4 groups according to albumin corrected-calcium quartiles. Composite end point comprised recurrent stroke, myocardial infarction, other ischemic vascular events, and all-cause mortality. Multivariable Cox or logistic regression was used to evaluate the independent association of albumin corrected-calcium with all-cause mortality, recurrent stroke, composite end point, and poor functional outcome (modified Rankin Scale score ≥3). ResultsCompared with the lowest calcium quartile (<2.16 mmol/L), the adjusted hazard ratio (95% CI) of the top quartile (≥2.31 mmol/L) was 1.56 (1.11–2.18) for all-cause mortality, 1.06 (0.87–1.28) for recurrent stroke and 1.08 (0.90–1.01) for composite end point, and the adjusted odds ratio for poor functional outcome was 1.18 (0.96–1.44). The addition of serum calcium to conventional risk factors improved risk prediction of all-cause mortality, leading to a small but significant increase in C-statistics and reclassification with non-significant integrated discrimination improvement (C-statistics, p = 0.02; net reclassification index 11.8%, p = 0.038; integrated discrimination improvement 0.08%, p = 0.42). ConclusionsHigh serum calcium levels at baseline were associated with all-cause mortality at 1-year after ischemic stroke, suggesting that serum calcium may be a potential prognostic biomarker and therapeutic target for ischemic stroke.

Iron chelates have little to no effect on the severity of Fusarium wilt of bananas in soils of the humid tropics

Previous research has shown that application of iron chelates to soil reduces Fusarium wilt in several crop species. The aim of this work was to test the effect for bananas grown in tropical soils. Disease severity and plant characteristics were measured in banana plants (cv. Ducasse, Musa ABB) grown in pots inoculated with Fusarium oxysporum f. sp. cubense, Race 1 in two experiments. Experiment 1 compared amendment with iron chelates (with ligands of differing iron binding stability) with water, plus an uninoculated unamended control, in two tropical Australian soils. Experiment 2 examined the effect of Fe-HBED application rate with high or low calcium addition. In Experiment 1, iron-saturated chelate application did not significantly affect disease severity or plant tissue iron concentration, irrespective of the iron binding stability of the chelate. In Experiment 2, disease severity was not affected by Fe-HBED or calcium application rate. The concentrations of iron and aluminium in plants were both somewhat affected by the addition of Fe-HBED, calcium and their interaction. Fusarium wilt of bananas was not affected by addition of iron chelates to these soils. The lack of effect was likely due to high iron availability in the soils overwhelming the capacity of the treatments to alter iron availability to the host plant and pathogen. Application of strong chelating ligands increased the concentration of aluminium and decreased the concentration of manganese in plant tissue, with possible detrimental effects.

Exchange of Proteins in Liposomes through Streptolysin O Pores.

Liposomes, which are vesicles surrounded by lipid membranes, can be used as biochemical reactors by encapsulating various reactions. Accordingly, they are useful for studying cellular functions under controlled conditions that mimic the environment within a cell. However, one of the shortcomings of liposomes as biochemical reactors is the difficulty of introducing or removing proteins due to the impermeability of the membrane. In this study, we established a method for exchanging proteins in liposomes by forming reversible pores in the membrane. We used the toxic protein streptolysin O (SLO); this forms pores in membranes made of phospholipids containing cholesterol that can be closed by the addition of calcium ions. After optimizing the experimental procedure and lipid composition, we observed the exchange of fluorescent proteins (transferrin Alexa Fluor 488 and 647) in 9.9 % of liposomes. We also introduced T7 RNA polymerase, a 98-kDa enzyme, and observed RNA synthesis in ∼8 % of liposomes. Our findings establish a new method for controlling the internal protein composition of liposomes, thereby increasing their utility as bioreactors.

Improved corrosion response of squeeze-cast AZ91 magnesium alloy with calcium and bismuth additions

The corrosion responses of the individual and combined Ca and Bi incorporated AZ91 alloy are investigated through the immersion, hydrogen evolution, and electrochemical tests. All the modified alloys exhibit better corrosion resistance than the base AZ91 alloy. The AZ91 + 1.0Ca (wt%) alloy unveils better corrosion resistance than the AZ91 + 0.5Bi (wt%) alloy owing to the Al2Ca phase formation. The combined Ca and Bi added AZ91 alloys acquire better corrosion resistance than the individual Ca or Bi added AZ91 alloys. The AZ91 + 2.0Ca + 0.5Bi (wt%) and AZ91 + 1.0Ca + 1.0Bi (wt%) alloys exhibit the lowest and the highest corrosion rates among the combined additions.

Dietary Calcium Alleviates Fluorine-Induced Liver Injury in Rats by Mitochondrial Apoptosis Pathway.

Excessive fluoride (F) exposure can lead to liver damage; moreover, recent studies found that the addition of appropriate calcium (Ca) can alleviate the symptom of skeletal fluorosis. However, whether Ca can relieve F-induced liver damage through the mitochondrial apoptosis pathway has not been reported yet. Therefore, we assessed the liver morphology, serum transaminase content, liver oxidative stress-related enzymes, and apoptosis-related gene and protein expression in Sprague Dawley (SD) rats treated with 150 mg/L sodium fluoride (NaF) and different concentrations of calcium carbonate (CaCO3) for 120 days. Our results showed that NaF brought out pathological changes in liver morphology, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels increased, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) content decreased, and malondialdehyde (MDA) content increased, suggesting that NaF caused hepatotoxicity and oxidative stress. In addition, the results of quantitative real-time PCR (qRT-PCR) and immunohistochemistry showed that NaF exposure upregulated the expression of Bcl-2-associated x protein (Bax), rho-related coiled-coil kinase 1 (ROCK1), cytochrome C (Cyto-C) mRNA and protein (P < 0.01), and downregulated B cell lymphoma 2 (Bcl-2) protein and mRNA (P < 0.01), indicating that excessive F exposure activated mitochondrial-mediated apoptosis in the liver. However, the addition of 1% CaCO3 to the diet significantly increased the expression of anti-apoptotic gene Bcl-2 (P < 0.01), inhibited the activation of the mitochondrial apoptosis pathway, and reduced mitochondrial damage. In summary, supplementing 1% CaCO3 in the diet can alleviate the NaF-induced liver cell damage through the mitochondrial apoptosis pathway.

Feeding Of Calcium and Protein Macroparticle Or Microparticle With Bitter Mustard Root On Intestinal Bacteria Population And Nutrient Intake In Quail

This study aims to feeding of protein source feed ingredients in macroparticle or microparticles with the addition of bitter mustard root to the small intestinal bacteria population and nutrient intake in quails. The experimental livestock used by the layer phase quail were 200 birds with an average weight of 149 ± 10.88 g, protein feed ingredients in the form of soybean meal and fish meal, calcium comes from eggshells and mustard root powder as a prebiotic. The research design was a completely randomized design with 4 treatment and 5 replaice (each 10 bird). The treatment were P1= Feed with protein and calcium macroparticles; P2= Feed with protein and calcium microparticles; P3= Feed with protein and calcium macroparticles + bitter mustard root powder 1,2% dan P4= Feed with protein and calcium microparticles + bitter mustard root powder 1,2%. The parameters measured were population of lactic acid bacteria, coliform, pH, protein and calcium intake. Data were analyzed using analysis of variance (Anova) and different test (Duncan) on 5% level. The results showed that the use of rations with protein and calcium feed ingredients in macroparticles or microparticles with the addition of bitter mustard root powder had a significant effect (p&lt;0,05) on population of small intestine bacteria and nutrient intake. The use of protein and calcium microparticles with the addition of 1.2% bitter mustard root powder (P4) was able to increase the population of lactic acid bacteria and nutrient intake (protein and calcium) and decreased coliform population and small intestine pH compared to other treatments (P1-P3). The conclusion is feeding of protein and calcium microparticles and addition of 1.2% bitter mustard root powder could increase the population of lactic acid bacteria, protein and calcium intake and reduce the coliform population and the pH of the small intestine.

Label-Free SERS Analysis of Urine Using a 3D-Stacked AgNW-Glass Fiber Filter Sensor for the Diagnosis of Pancreatic Cancer and Prostate Cancer.

Metabolomics shows tremendous potential for the early diagnosis and screening of cancer. For clinical application as an effective diagnostic tool, however, improved analytical methods for complex biological fluids are required. Here, we developed a reliable rapid urine analysis system based on surface-enhanced Raman spectroscopy (SERS) using 3D-stacked silver nanowires (AgNWs) on a glass fiber filter (GFF) sensor and applied it to the diagnosis of pancreatic cancer and prostate cancer. Urine samples were pretreated with centrifugation to remove large debris and with calcium ion addition to improve the binding of metabolites to AgNWs. The label-free urine-SERS detection using the AgNW-GFF SERS sensor showed different spectral patterns and distinguishable specific peaks in three groups: normal control (n = 30), pancreatic cancer (n = 22), and prostate cancer (n = 22). Multivariate analyses of SERS spectra using unsupervised principal component analysis and supervised orthogonal partial least-squares discriminant analysis showed excellent discrimination between the pancreatic cancer group and the prostate cancer group as well as between the normal control group and the combined cancer groups. The results demonstrate the great potential of the urine-SERS analysis system using the AgNW-GFF SERS sensor for the noninvasive diagnosis and screening of cancers.

Fluoride release from carbonate-rich fluorapatite during managed aquifer recharge: Model-based development of mitigation strategies

Fluoride-bearing apatite minerals such as fluorapatite (FAP: Ca10(PO4)6F2) and related carbonate-rich fluorapatites (CFA: Ca10(PO4)5(CO3,F)F2), which occur ubiquitously as trace components of rocks and sediments, may act as sources for geogenic groundwater fluoride contamination. CFA dissolution often occurs in conjunction with declining dissolved calcium concentrations. Therefore, managed aquifer recharge (MAR) operations using deionised or low calcium source water are at risk of disturbing the naturally persisting geochemical equilibrium between CFA and the ambient groundwater and induce fluoride mobilisation. In this study, we employ reactive transport modelling to investigate how an engineered manipulation of the MAR source water composition might mitigate such groundwater fluoride contamination. Based on a previously developed and calibrated model for Australia's largest groundwater replenishment operation, we investigate the efficiency of (i) raising aqueous calcium concentration through the addition of CaCl2 or Ca(OH)2 amendment, (ii) raising aqueous sodium concentrations through the addition of NaCl or sea salt amendment and (iii) raising the pH. The modelling results illustrate in detail how the geochemical zonation around injection boreholes evolves over time and how this affects fluoride release and attenuation for the different amendment types. Treatments involving the addition of calcium and sodium in the source water are both found to be effective at reducing maximum groundwater fluoride concentrations during MAR, with calcium generally producing the greatest reduction in maximum fluoride concentrations. In contrast, increasing the injectate pH was found to be inefficient in reducing fluoride concentrations significantly due to the strong pH buffering effect of the aquifer sediments.

Effect of Ca2+ and Mg2+ ions on the sintering and spectroscopic properties of cr‐doped yttrium aluminum garnet ceramics

AbstractIn this work, we investigated the effects of Ca2+ and Mg2+ ions and annealing temperature on the spectroscopic parameters of chromium‐doped yttrium aluminum garnet ceramics (Cr:YAG). Samples were obtained with either a separate or a simultaneous addition of calcium and magnesium oxides. To achieve this, aqueous suspensions were prepared using Y2O3, Al2O3, Cr2O3, MgO, and CaO high‐purity powders as raw materials. The obtained suspensions were freeze‐granulated, pressed into pellets, debinded, and subjected to reactive sintering in vacuum at 1715°C for 6 h. Each material was annealed in air with temperatures between 1300 and 1700°C. Samples were also compared to Cr:YAG ceramics with the addition of silica as a sintering aid. All the materials obtained were then exposed to 445 nm excitation, and emission spectra in the visible and infrared wavelengths were recorded. The results showed that the emission spectra of Cr:YAG ceramics varied according to the annealing conditions: as‐sintered samples exhibited strong emissions of around 680 nm and, after air annealing, of around 1400 nm. This phenomenon is attributed to the Cr3+→Cr4+ transition. Samples doped solely with MgO exhibited the highest emission intensity in the infrared region. Thus, Mg2+ ions provided the best conversion efficiency of chromium ions.

Effect of calcium on the electrochemical behaviors and discharge performance of Al–Sn alloy as anodes for Al–air batteries

The effect of calcium on the microstructure, electrochemical behaviors and discharge properties of Al–0.1Sn alloys as anodes for alkaline Al–air batteries are investigated. Addition of calcium to Al–0.1Sn alloys promotes the precipitation of CaSn phase and Al4Ca phase in the matrix. The Al–0.1Sn alloys with calcium (≤ 0.16 wt%) exhibit better discharge performance and higher anode efficiency, which is due to the oxidation of CaSn phases introducing one layer of Ca(OH)2-containing film that inhibits the hydrogen evolution reaction of the anode. The Al–0.1Sn–0.08Ca alloy shows a discharge capacity as high as 2495.75 Ah kg−1 (83.75% anode efficiency) and a peak energy density of 3793.54 Wh kg−1 at 20 mA cm−2, which are 24.8% and 18.9% higher than for the Al–0.1Sn alloy. By contrast, the Al4Ca phase formed by excessive calcium strongly aggravates the hydrogen evolution reaction of the Al–0.1Sn alloy, which is not conducive to its discharge performance. Furthermore, at high current densities, the discharge behaviors of calcium-containing alloys are significantly suppressed by the Ca(OH)2-containing film. Therefore, the Al–0.1Sn–0.08Ca alloy is suitable to serve as anode materials for Al-air batteries at low current densities.

Ole e 3, a Candidate for in vivo Diagnosis of Polcalcin Sensitization

Introduction: Polcalcins belong to the family of calcium-binding proteins. They are ubiquitous in the plant kingdom and highly conserved, which leads to these panallergens showing a high degree of inter-cross-reactivity. They are responsible for allergic polysensitization, and therefore, their diagnosis is necessary for correct selection of immunotherapy. The objectives were to develop a method to purify native polcalcin with intact allergenic properties and to validate its use for diagnosis of polcalcin sensitization. Methods: Ole e 3 was purified by immunoaffinity chromatography using anti-rChe a 3 polyclonal antibodies and identified by mass spectrometry. Calcium-binding assays were performed in immunoblot and ELISA assays. Diagnostic capacity of Ole e 3 was analyzed by ELISA and compared to ImmunoCAP with sera from a pollen-sensitized population. Cross-reactivity with other polcalcins was investigated by ImmunoCAP inhibition. Results: Immunogenicity of purified Ole e 3 was not affected by the addition of calcium. However, the presence of a calcium chelator agent completely inhibited IgG binding by immunoblot and produced a 32.3% reduction in IgE binding by ELISA. Ole e 3 enabled diagnosis of polcalcin-sensitized patients, and a good correlation was revealed with ImmunoCAP. A 50% inhibition in IgE binding was obtained with 2.8 ng of Ole e 3 for rBet v 4 and 3.9 ng for rPhl p 7. Discussion/Conclusion: Native Ole e 3 was purified by maintaining its allergenic properties. This innovative method enables obtaining this active native allergen to be used for in vivo diagnosis of polcalcin sensitization.

Interdependence of Contributing Factors Governing Dead-End Fouling of Nanofiltration Membranes.

Cake-enhanced concentration polarization (CECP) has been ascribed as the main cause of flux decline in dead-end filtration. An unfamiliar approach was used to investigate the role of CECP effects in the fouling of a nanofiltration membrane (NF-270) that poorly reject salts. Membrane–foulant affinity interaction energies were calculated from measured contact angles of foulants and membrane coupons based on the van der Waals/acid–base approach, and linked to resistance due to adsorption (Ra). In addition, other fouling mechanisms and resistance parameters were investigated using model organic and colloidal foulants. After selection, the foulants and membranes were characterized for various properties, and fouling experiments were conducted under controlled conditions. The fouled membranes were further characterized to gain more understanding of the fouling layer properties and flux decline mechanisms. Sodium alginate and latex greatly reduced membrane permeate flux as the flux declined by 86% and 59%, respectively, while there was minor flux decline when aluminum oxide was used as model foulant (<15% flux decline). More flux decline was noted when fouling was conducted with a combination of organic and colloidal foulants. Contrary to other studies, the addition of calcium did not seem to influence individual and combined fouling trends. Foulants adsorbed more on the membrane surface as the membrane–foulant affinity interactions became more attractive and pore blocking by the foulants was not important for these experiments. Hydraulic resistance due to cake formation (Rc) had a higher contributing effect on flux decline, while CECP effects were not substantial.

Production of Bacterial Amylase and Evaluation for Starch Hydrolysis

In starch degrading industry, the first step to be performed is gelatinization of starch granules at elevated temperature. This process tends to form a viscose suspension, thus making mixing and pumping a huge challenge. Therefore, to lower the viscosity of starch paste thermostable enzymes are added for breaking down the polysaccharides into oligosaccharides by a process known as liquefaction. Therefore, the availability of these enzymes can be considered a prerequisite to start successful starch liquefaction and saccharification industry. The main objective of this study was, therefore, to produce efficient microbial amylolytic enzymes for starch hydrolysis. One bacterial isolate designated as BACC 2107 was isolated from locally collected samples. The enzyme has optimum activity at pH of 5.0 and 70°C. The addition of calcium in the reaction mixture was shown to stabilize the enzyme. The isolate BACC 2107 was able to grow under solid-state fermentation (SSF) using wheat bran as a solid substrate. Optimum enzyme production was recorded at 32°C, and at 120 h of incubation and at a moisture content of 75%. Addition of peptone to the SSF medium as an organic nitrogen supplement enhanced enzyme production. The enzyme was used to hydrolyze a 25% (w/v) of starch at 70°C and pH 5.0, and the resulting hydrolysate was analyzed on TLC plates. After 4 h hydrolysis, the TLC chromatogram showed the release of glucose, maltose, maltotriose, and other oligosaccharides, indicating that the enzyme is endo-acting alpha-amylase. The results of this study show that amylase from BACC 2107 has a good potential to be used in starch liquefaction and saccharification processes. The ability of the isolate to grow and produce the enzyme under SSF using cheap agro-industrial wastes could help to greatly reduce the production cost of the enzyme.

Sulfur dioxide removal by mesoporous silica KCC-1 modified with low-coverage metal nitrates

The removal of sulfur dioxide (SO2) from flue gas using fibrous mesoporous silica KCC-1 synthesized via microwave-assisted hydrothermal method was observed. The sorbent was modified by introducing nitrate salts of sodium (Na) and calcium (Ca) at 5 wt. % metal loading via incipient wet impregnation method. The SO2 breakthrough experiment was conducted in a vertical quartz-column reactor at atmospheric pressure and temperature of 323 K in the presence of 0.3 % SO2/N2. The SEM micrograph of KCC-1 exhibited a well-defined fibrous morphology consisting of colloidal spheres of 240–1160 nm in diameter. Addition of metal nitrates resulted in the reduction of surface area, total pore volume and minor breakage of the silica framework. The adsorption capacities of all samples were measured at C/C0 = 0.5, where the addition of sodium (Na5/KCC-1) and calcium (Ca5/KCC-1) enhanced the removal capacity by 1.88 and 2 times higher than the parent KCC-1 respectively. Even though sodium is expected to achieve better removal capacity due to its higher basicity and dispersion related to the lower crystallite size, its performance ultimately suffered from significant agglomeration of sodium oxide which created pore blockage, subsequently resulting in poor accessibility to the active sites.

Enhancement of Yield and Quality of Guava cv. Lucknow-49 by Foliar Application of Nutrients under High-Density Planting System

In view of the importance of foliar application of macro and micro nutrients to increase the yield and quality of guava under high density planting system, an experiment was laid out in a randomized complete block design consisting of nine treatment combinations with three replications. [(Control - Fertigation alone), (NPK (19:19:19)), (NPK + Zn), (NPK + Ca), (NPK + B), (NPK + Zn + Ca), (NPK + Zn + B), (NPK + Ca + B), (NPK + Zn + Ca + B). Among the treatments, fruit weight (225.22 g), fruit volume (215.35 ml),number of fruits per plant (80.35), fruit yield per plant(17.67 kg plant-1), TSS(10.60 0Brix), titratable acidity (0.196 %) and pectin content (1.31 %) was found to be significantly higher with the foliar application of NPK @ 1% + Zn @ 0.5 % + B @ 0.4%. The foliar spray of NPK @ 1% + Ca@ 0.2% + B@ 0.4% significantly increased the fruit diameter (7.85 cm), and ascorbic acid content (159.84 mg 100g-1). Thus, foliar spray of NPK, zinc and boron maintained more number of fruits per plant and improved the fruit set leading to an 18% increase in yield. Whereas, the addition of calcium to the plants increased the ascorbic acid content of the fruit and pectin that enhanced the shelf life of the fruit

Influence of Calcium Lactate and Tripotassium Citrate on the Production of Stable and Acceptable Calcium-Enriched Soymilk

In the current study, calcium lactate (ca-lactate) was used as a calcium source and tripotassium citrate (TPC) as chelating agents to produce calcium-enriched soymilk with calcium content equivalent to cow’s milk (120 mg/100mL). Physicochemical properties of calcium-enriched soymilk, including nutritional composition, pH, titratable acidity, particle diameter, sedimentation, viscosity, ion conductivity, and sensory evaluation were investigated. Our results showed significant differences (P&lt;.05) in moisture, ash content, titratable acidity, and ion conductivity after calcium and TPC were added. Moreover, the addition of calcium decreased the pH of soymilk from 6.69 to 6.21-6.51. The higher concentration of calcium also increased the calcium content, particle diameter, sedimentation, and viscosity, while the reverse results were shown when TPC was added. The intensities perceived of mouthfeel, visual appearance, and overall acceptability were greatly varied among calcium-enriched soymilks. The exact proportion of ca-lactate and TPC were able to produce calcium-enriched soymilk regarding higher stability during storage and great acceptability of the final product.

Structural, gelation properties and microstructure of rice glutelin/sugar beet pectin composite gels: Effects of ionic strengths

In this study, the rice glutelin (RG)/sugar beet pectin (SBP) composite gels were prepared by laccase induced cross-linking and subsequent heat treatment, and the effects of different calcium ion concentrations (0–400 mM) on the gelation, structural properties and microstructure of the RG/SBP composite gels were investigated. The results showed that the addition of 200 mM calcium ion could improve the rheological, textural properties and water holding capacity of the RG/SBP composite gels. The addition of SBP and calcium ions enhanced the hydrophobic interaction between RG molecules, thereby increased the gel properties of RG. The changes in Raman spectroscopy reflected the positive effect of the addition of SBP and calcium ions on the formation of a denser and more homogeneous protein gel, as evidenced by the results of scanning electron microscopy. Overall, SBP and calcium ions could be applied to the plant protein gel systems as gel-strengthening agents.

Effect of calcium addition to aerobic granular sludge systems under high (conventional SBR) and low (simultaneous fill/draw SBR) selection pressure

This paper investigated the effect of calcium addition on the formation and properties of aerobic granules under high (conventional SBR) and low (simultaneous fill/draw SBR) selection pressure. Additionally, the simultaneous removal of carbon, nitrogen, and phosphorus, and the operational stability were assessed. The conventional SBRs showed earlier granule development (20 days) than the simultaneous fill/draw SBRs. The effect of calcium on granulation was more accentuated in conventional SBRs, forming larger granules in a shorter interval of time due to the higher EPS production. Additionally, higher amounts of calcium were found in the EPS matrix, mainly during the formation of granules. The operation regime and the addition of calcium did not affect the removal of carbon, nitrogen, and phosphorus. However, they both influenced the granulation time, settleability characteristics, size, and granule composition.

Characterization and Ca2+-induced expression of calmodulin (CaM) in marine dinoflagellates

Calmodulin (CaM) is one of the major Ca2+-binding proteins in the cells, and it plays multiple roles in several Ca2+ signaling pathways and regulating the activities of other proteins. In the present study, we characterized CaM genes from the marine dinoflagellates Amphidinium carterae, Cochlodinium polykrikoides, Prorocentrum micans, and P. minimum, and examined their expression patterns upon the addition and chelation of calcium. Their cDNAs had same ORF length (450 bp) and encoded the same protein, but with few nucleotide differences in the ORF and different 3′- and 5′ untranslated regions (UTRs). The four CaM proteins consist of four EF-hand Ca2+-binding motifs, two N-terminal domains and two C-terminal domains, and they were highly conserved within eukaryotes. The CaM gene expressions in the tested species increased by calcium treatments; however, they were significantly down-regulated by the calcium-chelator EGTA. The CaM genes of the test species were inducible and regulated by different calcium doses, suggesting their major role in calcium regulation in dinoflagellates.