Addition Of Calcium Research Articles

Calcium-rich dairy matrix protects better than mineral calcium against colonic luminal haem-induced alterations in male rats

The haemoglobin content in meat is consistently associated with an increased risk of colorectal cancer, whereas calcium may play a role as a chemopreventive agent. Using rodent models, calcium salts have been shown to prevent the promotion of haem-induced and red meat-induced colorectal carcinogenesis by limiting the bioavailability of the gut luminal haem iron. Therefore, this study aimed to compare impacts of dietary calcium provided as calcium salts or dairy matrix on gut homoeostasis perturbations by high haeminic or non-haeminic iron intakes. A 3-week intervention study was conducted using Fischer 344 rats. Compared to the ferric citrate-enriched diet, the haemoglobin-enriched diet led to increased faecal, mucosal, and urinary lipoperoxidation-related biomarkers, resulting from higher gut luminal haem iron bioavailability. This redox imbalance was associated to a dysbiosis of faecal microbiota. The addition of calcium to haemoglobin-enriched diets limited haem iron bioavailability and counteracted redox imbalance, with improved preventive efficacy when calcium was provided in dairy matrix. Data integration revealed correlations between haem-induced lipoperoxidation products and bacterial communities belonging to Peptococcaceae, Eubacterium coprostanoligenes group, and Bifidobacteriaceae. This integrated approach provides evidence of the benefits of dairy matrix as a dietary calcium vehicle to counteract the deleterious side-effects of meat consumption.

Impact of biochemical properties on the gelation of EPS extracted from aerobic granules

Extracellular Polymeric Substances (EPS) extracted from aerobic granular sludge are a promising source of gel-forming biopolymers. Gaining insights on the charge distribution of these polymers was performed through a fractionation using anionic chromatography. A gelling factor (GF) based on the apparent gel volume and the reactivity of polymers to calcium was attributed to each eluted fraction. The GF values of the eluted anionic EPS correlated with their negative charge. A GF of 0.04 ± 0.03 is measured for molecules eluted at NaCl 0.25 M and a GF of 0.32 ± 0.02 for the molecules eluted at NaCl 0.75 M. However, upon reaching a very high negative charge (elution at NaCl 1 M), the gelation capacity decreases. The size distribution of gelling molecules was analyzed by Size Exclusion Chromatography. High Molecular Weight (MW) molecules are predominantly involved in gelation (between 65 % and 100 % of the high molecular weight fraction from each sample) while low MW molecules participation is relatively limited (lower than 40 % of the low molecular weight fraction from each sample). Moreover, infra-red spectroscopy analysis of the molecules before and after calcium addition showed that mostly proteins and polysaccharides contribute to the hydrogel formation. Colorimetric methods showed that around 60 % of the uronic acids present in the samples could form hydrogels whereas proteins’ participation varied between 0 % and 100 % depending on the fraction.Thus, modulating EPS extraction and purification methods to ensure the preservation of their molecular weight and the selection of appropriate negative charge could be a strategy for EPS valorization.

Effect of Different Calcium and Magnesium Treatments on the Evolution of Nonmetallic Inclusions in AH36 Ship Plate Steel

Comprehensive thermodynamic calculations and high‐temperature experiments are performed to systematically evaluate the effect of calcium and magnesium additions on the modification and control of inclusions in AH36 ship plate steel. The results show that Al2O3 or MgAl2O4 inclusions are formed under the casting temperature conditions. Calcium treatment modifies the inclusions into calcium aluminate, of which components partially fall into the liquidus region, and the aspect ratio and number density of inclusions became smaller, avoiding nozzle clogging, but the inclusions are easy to gather and grow up, which would affect the steel properties. Magnesium treatment modifies the inclusions into dispersed magnesium‐aluminum spinel with small size. However, the number density and aspect ratio of inclusions increase, as well as the melting points of inclusions are high, which would easily cause nozzle clogging. When calcium–magnesium synergistic treatment, with the increase of magnesium proportion, the inclusions types increased, and the liquidus area of inclusions became narrower until it disappeared. Synergistic treatment with more calcium and less magnesium (Ca2Mg1) is optimal since the inclusions were fine and diffuse, and the corresponding liquidus area of inclusions is wider than the calcium treatment.

Effect of Calcium Addition on Oxide and Sulfide Inclusions in Heavy Steel Ingot Simulated by Lab Experiments

The effect of calcium addition on inclusions (oxides and sulfides) in heavy steel ingot is investigated via lab experiments and thermodynamic calculation. The characteristics (chemistry, size, morphology, and number) of inclusions in the steel samples are investigated by scanning electron microscope with an energy‐dispersive spectrometer. The three‐dimensional morphology of inclusions is investigated by the nonaqueous solution electrolysis method. Inclusions in the fast‐quenched steel are changed from Al2O3 to Al2O3–CaO, Al2O3–CaO–CaS, and CaS after Ca addition. After slow cooling, inclusions in the solid steels are changed from Al2O3, single MnS, and Al2O3–MnS complex inclusions to Al2O3–CaO–CaS–MnS and CaS–MnS. The evolution trajectory of inclusions is Al2O3→Al2O3–CaO→Al2O3–CaO–CaS→Al2O3–CaO–CaS–MnS. With increasing Ca content in the steel, the number density and proportion of single MnS inclusions decrease. The formation mechanism of inclusions after Ca addition is explained by thermodynamic calculation.

Formation mechanism and control of a kind of pit-shaped defect in Cf53 rolled products

Aiming at the frequent issue of pit-shaped surface defects in S-bearing and Al-killed steel products and the related poor castability due to submerged entry nozzle (SEN) clogging, the melting and casting process of a popular auto steel Cf53 has been studied based on in-situ investigation and experimental analysis. To clarify the generation of the pit-shaped defects, the local surface chemistry, evolution of steel inclusions throughout the melting process, SEN clogging substances, and the internal relationship among them were systematically analyzed. The results show that this type of defect in the Cf53 rolled products is caused by the large-sized composite inclusions rich in CaS, which originate from the molten steel during the refining process, gradually accumulate on the inner wall of the SEN during casting, and finally lead to SEN clogging. The loose structure of clogging inclusions makes them prone to fall off into the mold and get trapped by solidifying steel shell. The formation mechanism of the inclusions was studied through FactSage software calculation. The results show that the increase in total sulfur and total calcium content, and the decrease in total oxygen content and temperature in steel will lead to CaS inclusion formation, which agrees reasonably well with experimental results. An optimized refining process to reduce calcium addition into molten steel is proposed accordingly, which achieves a remarkably alleviation in casting SEN clogging and an elimination of the pit-shaped defects on the final rolled products as well.

Effects of black bean cell wall pectin by exogenous calcium ions: Insight into the metabolomics, physicochemical properties and anti-digestive capacity

In this work, the metabolomics, physicochemical and in vitro digestion properties of black beans influenced by different calcium ion solutions (0, 0.5 %, 1 %, and 2 %) were explored. The addition of calcium ions had a significant effect on the metabolic processing of black beans, including 16 differential metabolites and 4 metabolic pathways related to the cell wall. From the results of FT-IR and ICP-OES, it was confirmed that calcium ions can interact with COO− in non-methylated galacturonic acid in pectin to form calcium carboxylate strengthening the middle lamellae of the cell wall. Based on this mechanism, the soaked beans with an intact and dense cell structure were verified by the analyses of SEM and CLSM. Compared with other soaked beans, BB-2 exhibited lower cell permeability with electrical conductivity value decreased to 0.60 μs·cm−1. Additionally, BB-2 demonstrated slower digestion properties with digestion rate coefficient at 0.0020 min−1 and digestion extent only at 30.83 %, which is attributed to its increasingly compact cell wall and densely cellular matrix. This study illustrates the effect of calcium ions on the cellular structure of black beans, providing an effective process method for low glycemic index diets.

Gallium-containing mesoporous nanoparticles influence in-vitro osteogenic and osteoclastic activity

Mesoporous silica nanoparticles were synthesized using a microemulsion-assisted sol-gel method, and calcium, gallium or a combination of both, were used as dopants. The influence of these metallic ions on the physicochemical properties of the nanoparticles was investigated by scanning and transmission electron microscopy, as well as N2 adsorption-desorption methods. The presence of calcium had a significant impact on the morphology and textural features of the nanoparticles. The addition of calcium increased the average diameter of the nanoparticles from 80 nm to 150 nm, while decreasing their specific surface area from 972 m2/g to 344 m2/g. The nanoparticles of all compositions were spheroidal, with a disordered mesoporous structure. An ion release study in cell culture medium demonstrated that gallium was released from the nanoparticles in a sustained manner. In direct contact with concentrations of up to 100 μg/mL of the nanoparticles, gallium-containing nanoparticles did not exhibit cytotoxicity towards pre-osteoblast MC3T3-E1 cells. Moreover, in vitro cell culture tests revealed that the addition of gallium to the nanoparticles enhanced osteogenic activity. Simultaneously, the nanoparticles disrupted the osteoclast differentiation of RAW 264.7 macrophage cells. These findings suggest that gallium-containing nanoparticles possess favorable physicochemical properties and biological characteristics, making them promising candidates for applications in bone tissue regeneration, particularly for unphysiological or pathological conditions such as osteoporosis.

Translatomics reveals the role of dietary calcium addition in regulating muscle fat deposition in pigs

Intramuscular fat (IMF) in pork holds significant importance for economic performance within the pig industry and dietary calcium supplementation enhances the accumulation of intramuscular fat. Additionally, calcium ions inhibit translation and reduce protein synthesis. However, the mechanism by which calcium regulates IMF deposition in muscle through translation remains largely unknown. In this study, we compared the ribosome profiles of the longissimus dorsi muscles of Duroc ×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document} Landrace ×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document} Large white pigs from the normal calcium (NC) group or calcium supplement (HC) group by Ribo-seq, and RNA-seq. By integrating multiple-omics analysis, we further discovered 437 genes that were transcriptionally unchanged but translationally altered and these genes were significantly enriched in the oxidative phosphorylation signaling pathway. Furthermore, experimental data showed that inhibiting the expression of COX10 and mtND4L increased triglyceride accumulation in C2C12 cells, providing new targets for intramuscular fat deposition. Finally, this work links dietary calcium, translation regulation and IMF deposition, providing a new strategy for both meat quality and economic performance within the pig industry.

Organization of hyaluronic acid molecules in solutions

The organization of hyaluronic acid (HA) solutions was investigated by small angle neutron scattering (SANS). It was demonstrated that HA formed clusters greater than several hundred nanometers. The SANS response revealed a weak correlation peak, corresponding to ordering over a distance scale of about 80 nm. At higher wave vectors, the SANS response indicated the presence of rod-like structures. Addition of calcium ions only weakly affects the structure of the HA solution, but significantly reduces its osmotic pressure. The osmotic component of the SANS response is in good agreement with the intensity obtained from direct osmotic pressure measurements. The results are consistent with the rigid structure of the HA molecule.Graphical abstract

Growth of Vannamei Shrimp (Litopeneaus vannamei) in Rearing Media with Different Salinities

The addition of calcium, phosphorus and magnesium minerals has been carried out separately in vannamei shrimp cultivation activities using fresh water media. Furthermore, the combination of the three types of potassium is expected to mutually fulfill the mineral needs of vannamei shrimp so that their growth becomes more optimal. This research aims to analyze the growth of vannamei shrimp reared in various media with different mineral levels. The treatments in this study were P1 (30 ppt), P2 (20 ppt), P3 (10 ppt), P4 (0 ppt without the addition of minerals), and P5 (0 ppt with the addition of various types of mineral sources). The research results show that the best SGR weight is found in P1 at 12.42%/day. The highest SR value was also obtained at P1, namely 65%. The SR and SGR values at P5 are higher than at P4, but still lower than at P1, P2, and P3. Based on these results, it is known that the growth of vannamei shrimp reared in fresh water media with added minerals has increased compared to vannamei shrimp reared in fresh water media without added minerals, but is still lower compared to the growth of vannamei shrimp reared in water media. sea. Furthermore, research is needed on adding other types of minerals to low salinity vannamei shrimp cultivation media.

The Effect of Bacteria-to-Calcium Ratio on Microbial-Induced Carbonate Precipitation (MICP) under Different Sequences of Calcium-Source Introduction.

To explore the effects of the introduction order of calcium sources and the bacteria-to-calcium ratio on the microbially induced calcium carbonate precipitation (MICP) product CaCO3 and to achieve the regulation of CaCO3 crystal morphology, the mineralisation products of MICP were compared after combining bacteria and calcium at ratios of 1/9, 2/9, 3/9, 4/9, 5/9, and 6/9. A bacterial solution was combined with a urea solution in two calcium addition modes: calcium-first and calcium-later modes. Finally, under the calcium-first addition method, the output of high-purity vaterite-type CaCO3 was achieved at bacteria-to-calcium ratios of 2/9 and 3/9; under the calcium-later addition method, the output of calcite-type CaCO3 could be stabilised, and the change in the bacteria-to-calcium ratio did not have much effect on its crystalline shape.

The Significance of Providing the Optimal Micronutrients to the Preterm Low Birth Weight Infants to Prevent Long-Term Health Consequences

Premature infants have less nutritional storage capacity and an underdeveloped body, which makes them particularly susceptible to malnutrition. Nutrient surplus and deficiency are possibilities when supplemental feeding is unbalanced. However, little is known about what kids should eat once they are discharged from the hospital. Since many bodily processes depend on micronutrients, it's critical to plan supplemental nutrition with an optimum consumption in mind. This written summary describes the requirements for long-chain polyunsaturated fatty acids (LCPUFA), iron, zinc, vitamin D, calcium, and phosphate for premature newborns receiving supplemental feeding. The scientific community is beginning to acknowledge the advantages of giving premature babies iron and vitamin D supplements. But as of right now, there isn't enough information available to make firm recommendations about the addition of calcium, phosphorus, zinc, and LCPUFAs. Nonetheless, the health of premature infants depends on the following micronutrients: Large chain polyunsaturated fats (LCPUFAs) support the development of the retina and brain, while calcium and phosphorus dosages are necessary to prevent metabolic bone disease (MBD) in preterm infants. It is obvious how understanding the variability of the premature population may help adapt nutritional planning in connection to the development rate, comorbidities, and thorough clinical history of the preterm newborn, even while we wait for consensus on these micronutrients.

Effect of Calcium Content on Characteristics of Inclusions in an Al‐Killed Steel

Laboratory experiments are performed to study the effect of T.Ca content in the molten steel on the composition, size, and quantity of inclusions. Different amounts of SiCa alloys are added into the molten steel to obtain samples with varied T.Ca contents. Samples are taken at 1, 5, 10, 15, and 20 min after the calcium addition to study the transformation of inclusions with time. After the addition of calcium into the molten steel, the size of pure liquid inclusions is small which are more difficult to be removed from the molten steel than solid ones, while partially liquid inclusions are easily removed from the molten steel so that the total oxygen content of the molten steel is lower. The size of solid inclusions is large due to their large coagulation coefficient value. The number density and area fraction of liquid inclusions are larger than solid inclusions due to the higher adhesion work required for the removal of liquid inclusions. The corrosion of MgO crucible easily occurs by the dissolved calcium in the molten steel. Then, the reaction between the reduced magnesium and inclusions in the molten can occur, leading to the generation of MgO–Al2O3 and CaO–MgO–Al2O3 inclusions.

In-Bath 3D Printing of Anisotropic Shape-Memory Cryogels Functionalized with Bone-Bioactive Nanoparticles.

Cryogels exhibit unique shape memory with full recovery and structural stability features after multiple injections. These constructs also possess enhanced cell permeability and nutrient diffusion when compared to typical bulk hydrogels. Volumetric processing of cryogels functionalized with nanosized units has potential to widen their biomedical applications, however this has remained challenging and relatively underexplored. In this study, we report a novel methodology that combines suspension 3D printing with directional freezing for the fabrication of nanocomposite cryogels with configurable anisotropy. When compared to conventional bulk or freeze-dried hydrogels, nanocomposite cryogel formulations exhibit excellent shape recovery (>95%) and higher pore connectivity. Suspension printing, assisted with a prechilled metal grid, was optimized to induce anisotropy. The addition of calcium- and phosphate-doped mesoporous silica nanoparticles into the cryogel matrix enhanced bioactivity toward orthopedic applications without hindering the printing process. Notably, the nanocomposite 3D printed cryogels exhibit injectable shape memory while also featuring a lamellar topography. The fabrication of these constructs was highly reproducible and exhibited potential for a cell-delivery injectable cryogel with no cytotoxicity to human-derived adipose stem cells. Hence, in this work, it was possible to combine a gravity defying 3D printed methodology with injectable and controlled anisotropic macroporous structures containing bioactive nanoparticles. This methodology ameliorates highly tunable injectable 3D printed anisotropic nanocomposite cryogels with a user-programmable degree of structural complexity.

Effect of Calcium Addition on the Aluminum Alloy A201 Foam

To study the effect of calcium on the porosity, sphericity, and microstructure of Al–Cu foams, a gradient calcium content (0.5, 1.0, 1.5, and 2.0 wt%) is added into aluminum A201 alloy (Al–Cu alloy) for the cellular aluminum foam preparation via the melt foaming method (TiH2 is used as a bubbling agent). Thereafter, the porosity of the prepared Al foams and their pore size are found to increase, and the sphericity of pores tends to approach to unit with calcium addition. This phenomenon is then explained through the modified thermophysical properties (i.e., surface tension and viscosity) of A201 alloy melts caused by the calcium addition. After the microstructure analysis, a bunch of secondary phases in the A201 + Ca alloy foams, e.g., CalAl2Si2, Al2Cu, and Al20CaTi2 as well as an eutectic phase with a great copper content Al8CaCu4 are detected by means of scanning electron microscopy/energy‐dispersive X‐Ray spectroscopy and X‐Ray diffraction analysis.

Preharvest calcium application boosts the biostimulatory effect of protein hydrolysate by improving the postharvest life of gerbera cut flower

Among the various categories of plant biostimulants currently available on the market, protein hydrolysates, primarily composed of a heterogeneous mixture of peptides and amino acids, have gradually gained prominence. Nevertheless, the positive effects of these products on the production and longevity of cut flowers are still not well-explored. The purpose of this research was thus to fill this gap by assessing the impacts of a plant-derived protein hydrolysate, with and without the addition of calcium (PH and PH+Ca), on the growth, quality, and vaselife of two cultivars of gerbera with different pigmentation (Brunello and Tommy, red and yellow, respectively). Regardless of cultivar, foliar application of PH improved growth, flower production, absorption of key nutrients, and photosynthetic performance, compared to the control. On the other hand, the PH+Ca treatment exhibited the best results during vaselife. For both cultivars, the application of PH+Ca increased the durability of gerbera flowers, reducing the weight loss by an average of 19 % on day 10 compared to untreated flowers. Although cultivar-dependent, the positive effects of the PH+Ca biostimulant were also observed on petal pigmentation during vase life. For the Tommy cultivar, for instance, the Chroma values of treated flowers remained unchanged during the post-harvest period, unlike what was observed for untreated flowers. Therefore, considering the positive effects resulting from the use of PH and PH+Ca on gerbera, it would be interesting to further investigate the use of biostimulants in floriculture to increase the sustainability of the sector and especially with regard to cut flower production, without reducing or even improving the performance that is conventionally achieved.

Selective extraction of potassium from raw nepheline materials

The global aluminium industry is ever-changing and primarily relies on bauxite as its traditional source. However, due to the finite reserves of processed bauxite, alternative sources need to be found. Nephelines have emerged as potential alumina sources. In addition to alumina, nepheline processing can yield marketable products such as soda, potash, cement, and rare metals.The objective of this study was to identify the ideal conditions for selectively extracting potassium from alkaline leaching solutions while separating it from sodium alkali, aluminium, and silicon during the comprehensive processing of nepheline syenites from the Kubasadyr deposit. This approach involved a two-stage hydrothermal leaching process with an incremental calcium addition. Under optimal conditions, the potassium extraction in the alkaline solution reached 93.91 %. The resulting leaching solution served as a feedstock for potassium sulfate production through the crystallization method. The preliminary selective separation of potassium played a crucial role in mitigating its adverse effects on the extraction of aluminium, which is the primary processed product; thus, the economic viability of production was enhanced.

Evaluation of fertilizer type and rate of application on tomato fruit quality

Growing vegetables is seen as a promising method for ensuring sustainable food and nutrition security in the tropics. The rise in demand for tomatoes in this region has influenced production practices and strategies to meet local and export needs. Many tropical countries have expanded their tomato cultivation to fulfill local demand and potentially generate income from exports, as they have become increasingly important for food and nutrition security. Various successful production systems have been implemented around the world to grow tomatoes. However, Zimbabwean farmers are experiencing decreased yields and shorter shelf lives of tomatoes due to insufficient use of calcium, despite the pivotal role agrochemicals have played in boosting global agricultural production. This study aimed to assess the impact of different types and levels of basal chemical fertilizers on tomato quality. The three types of basal fertilizers used were Compound D [7:14:7], Gypsum, and a combination of both in equal proportions. These fertilizers were applied at rates of 50, 100, and 200 kg/ha. A Randomized Complete Block Design (RCBD) with four replications was utilized for the study. Tomato quality parameters such as ripe fruit count, size, disease prevalence, firmness, total soluble solids, weight loss, and shelf-life were measured. The results revealed significant differences (p<0.05) between the application rates and types of basal chemical fertilizers. The combination of Compound D and Gypsum had the most noTable effect, as the addition of calcium and sulfur improved the quality of tomato fruits. Ultimately, it was concluded that the best tomato quality was achieved when using a combination of Compound D and Gypsum at a rate of 200 kg/ha. These findings highlight the urgent need to promote the use of gypsum in tomato production

Electrical properties of A-site Ca-doped LaNb1-xAsxO4-δ ceramics

The electrical properties of A-site Ca-doped LaNbO4 with the addition of As in the B-site, have been investigated. Total, grain- and specific grain boundary electric conductivities in different oxygen partial pressure, and water vapour partial pressure were determined. Additional conductivity measurements were performed in nitrogen, to suppress the possible p-type conductivity, focusing on protonic conductivity. The maximum measured total conductivity was recorded for La0.99Ca0.01Nb0.9As0.1O4-δ at 800 °C, which was equal to 1.2·10−4 S·cm−1 in H2O- humidified air, and 2.2·10−5 S·cm−1 in H2O- humidified N2. From the deconvoluted data, the lowest activation energies for grain conduction were obtained in both atmospheres for La0.99Ca0.01Nb0.7As0.3O4-δ. In the temperature range 400 °C – 550 °C it was 0.23 eV and 0.13 eV respectively for H2O- humidified air and H2O- humidified N2. The results show that the increasing arsenic amount mainly influences the activation energies, whereas the calcium addition slightly improves the grain conductivity. The pO2 experiments revealed that in oxidizing atmospheres, electron holes contribute to the conductivity. The high proton transfer numbers were obtained for each sample, peaking at tH+ = 0.91 for LaNb0.7As0.3O4 at 400 °C. Interestingly, even at elevated temperatures relatively high values are obtained where tH+ = 0.87 was recorded at 800 °C for La0.99Ca0.01Nb0.9As0.1O4-δ.

Influence of citrate- and phosphate-based calcium sequestering salts on the disruption of casein micelles

The disruption of casein micelles through the addition of calcium sequestering salts (CSS) disodium phosphate (DSP), disodium pyrophosphate (DSPP) and tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), sodium hexametaphosphate (SHMP) and trisodium citrate (TSC) at 10, 15, 20 and 30 mEq/L levels was investigated in 5% micellar casein isolate (MCI) solution. All the CSS, except DSPP and TSPP, showed a decrease in particle size and viscosity with increasing concentration. The addition of 10–30 mEq/L of CSS to MCI decreased the protein-bound sedimentable Ca and P at pH 6.5 10 kDa-permeable Ca decreased with increasing concentration of DSP, DSPP, TSPP, STPP and SHMP. These results indicate that orthophosphates, pyrophosphates and polyphosphates combined with Ca to form insoluble Ca phosphate complexes together with casein. Higher amount of 10 kDa permeable Ca for MCI samples with TSC confirms the formation of soluble Ca-citrate complexes.