Influence Of Sodium Citrate Research Articles

Purification of pectin by ultrafiltration in combination with sodium citrate

Ultrafiltration is an effective method to improve the purity of pectin, but membrane fouling is an urgent problem to overcome. In this work, trisodium citrate, sodium caseinate and calcium caseinate were combined with ultrafiltration to separate and purify pectin extract. The molecular weight cutoff (MWCO) of the ultrafiltration membrane and the sodium citrate concentration were optimized using the color and clarity of the pectin extract as indices, and the influence of sodium citrate on the pectin particle size and zeta potential was further studied. Finally, the pectin extraction yield, some physicochemical indices, including galacturonic acid (Gal A) content, esterification degree, and ash content, and the surface morphology of the pectin particles were measured. The results showed that the ultrafiltration membrane fouling was effectively controlled and that the steady-state flux increased by 2-fold when the pectin extract was treated with a polyether sulfone (PES) UF membrane (100 kDa) in combination with sodium citrate at a concentration of 0.25 mg/ml. The pectin extraction yield increased to 16.4%, and the resulting pectin was a higher-ester refined pectin with a Gal A content of 89.7%, DE content of 77.42%, and ash content of 0.63%. The combination of sodium citrate and ultrafiltration was beneficial not only for improving the permeability and separation performance of the ultrafiltration process but also for providing an example of a monovalent salt as a precipitation agent.

Coelectrodeposition of crystalline copper-manganese oxide containing CuMn2O4 spinel for high energy supercapacitor application

In this study, copper manganese oxide films with various compositions were synthesized using electrochemical deposition technique. In order to achieve different chemical compositions, the influence of sodium citrate as a complex agent was investigated. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Brunauer-Emmet-Teller adsorption (BET) were used to study the morphology, chemical composition, crystal structure and surface area of deposited layers, respectively. We observed that by optimizing the citrate concentration in the electrodeposition electrolyte, improved capacitance of 744 F/g at 10 mV/s with retention capacitance of 91% over 10,000 cycles can be achieved. The obtained stability of copper-manganese oxide is 3 times and about 2 times higher than pristine copper oxide and manganese oxide, respectively. The enhanced stability of the achieved crystalline copper-manganese oxide ascribe to formation of CuMn2O4 spinel, improved ultrafine structure and a better chemical stability.

Controllable Synthesis of Nanostructured Ca-P Coating on Magnesium Alloys via Sodium Citrate Template-Assisted Hydrothermal Method and Its Corrosion Resistance

In this study, a nanostructured needle-like hydroxyapatite (HA) coating was prepared by the sodium citrate template-assisted hydrothermal method on magnesium alloy (AZ31). The influence of sodium citrate on the composition, microstructure and corrosion behavior of the coatings was studied. The results showed that with the increase in the mole ratio of Ca/sodium citrate from 1 to 13, the coating gradually changed from the needle-like morphology of HA to the flake morphology of β-tricalcium phosphate (β-TCP), which was related to the existing form of citrate in the solution and the trend of complexation reaction. When the mole ratio of Ca/sodium citrate was 1, the HA coating sample with the nano needle-like morphology had a high corrosion resistance (Rt = 235.300 ± 3.584 kΩ·cm2), which was almost 200 times that of the naked AZ31 alloy. Moreover, the corrosion rates of the Ca-P coated AZ31 alloy stabilized at about 0.55 mm/year and could provide more than 56 days of corrosion protection to the samples, which approximated the degradation rate requirement for biomaterials used as bone fixture.

The Influence of Sodium Citrate on the Characteristics and Biological Activity of Plasma Rich in Growth Factors

Aim: This study investigated the effect of sodium citrate on the properties and biological activity of plasma rich in growth factors (PRGF). Methods: PRGF was obtained from trisodium citrate and plain extraction tubes. Hematological parameters, growth factors' release kinetics from both PRGF clots and their releasates' biological effect on human bone cells were evaluated. Results: The platelet enrichment factor, the growth factors' content and the release kinetic of PRGF were similar for both groups. The proliferation, collagen type I synthesis and tissue-nonspecific alkaline phosphatase activity of human osteoblasts showed no statistically significant differences. Conclusion: The use of sodium citrate does not influence the composition, the growth factors' release kinetics or the biological effect of PRGF, but it increases its clinical versatility.

The effects of sodium citrate on compressive strength and paste microstructure of self-compacting concrete

The effects of sodium citrate on the evolution of compressive strength and paste microstructure of self-compacting concrete (SCC) were experimentally studied. Hydration degree and rheology measurement were carried out to investigate the mechanism of strength development. The results show that the difference in compressive strength of SCC depends on the dosage of sodium citrate and varies at different hydration ages. The compressive strength of SCC is improved with the addition of 0.025% sodium citrate, while it gradually decreases with the increase of sodium citrate dosage. The total porosity and harmful pore content of hardened pastes with small dosage of sodium citrate is lower than that of control sample, whereas it is higher when the dosage of sodium citrate exceeds 0.1%. The influence of sodium citrate on the compressive strength and pore structure of SCC is much obvious at early hydration ages. The incorporation of suitable dosage of sodium citrate improves the initial viscosity and dispersion resistance of fresh SCC, thus improving its pore structure and enhancing its compressive strength.

Impact of sodium citrate on structural properties of gluten.

The effect of sodium citrate on gluten-starch separation and physicochemical properties of gluten was studied. The results showed that the addition of sodium citrate to the dough caused to an improvement in the aggregation of gluten and increased gluten yield in comparison to the control by augmentation pH and approaching to the isoelectric point of glutenin and gliadin. Also, sodium citrate led a shift to larger particle size distribution of glutenin macropolymer (GMP). These observations demonstrated that under the influence of sodium citrate more thiol groups were oxidized and formed disulfide bonds, which increased the storage modulus and resistance to extension. Furthermore, in this sample the GMP gel was more elastic and stiffer.

The Influence of Sodium Citrate and Potassium Sodium Tartrate Compound Additives on Copper Electrodeposition

The Influence of Sodium Citrate and Potassium Sodium Tartrate Compound Additives on Copper Electrodeposition

Effect of Sodium Citrate on the Hydration Capacity of Hemihydrate Calcium Sulfate Whiskers

The influence of sodium citrate on the hydration capacity of hemihydrate calcium sulfate whiskers was investigated. The products were characterized by FTIR, SEM and XRD.The results show that the absorption of the sodium citrate on the surface of the hemihydrate calcium sulfate whiskers is not uniform, and the adsorption state also changed with the amount of sodium citrate. Sodium citrate plays role on the hydration capacity of hemihydrate calcium sulfate whiskers.

Electrochemical study of one-step electrodeposition of copper–indium–gallium alloys in acidic conditions as precursor layers for Cu(In,Ga)Se 2 thin film solar cells

This paper investigates one step electrodeposition of copper indium gallium metallic precursor layers for preparing CuIn 1− x Ga x Se 2 (CIGS) absorber layers in thin film solar cells (0 ≤ x ≤ 1). Electrodeposition was carried out in acidic aqueous solutions at about pH 2. At first partial single or binary electrodeposition systems Cu, In, Ga, Cu–Ga, Cu–In were investigated by cyclic voltammetry. Then ternary Cu–In–Ga electrodeposition system was studied. The nature of the supporting electrolyte (sodium sulfate vs. sodium chloride) and the influence of sodium citrate were more specifically investigated. The applied potential, the pH and the nature of the electrolyte were optimized to obtain x values around 0.3 needed for high efficiency devices. Depositions were carried out under potentiostatic conditions in a paddle cell configuration. The electrodeposited Cu–In–Ga alloys were annealed under Se atmosphere at temperatures between 400 and 600 °C to produce CIGS absorbers. Films were characterized by XRF, SEM and XRD analysis. Device efficiencies up to 9.3% are achieved for optimal gallium content.

Mechanisms of drug release in citrate buffered HPMC matrices

Few studies report the effects of alkalizing buffers in HPMC matrices. These agents are incorporated to provide micro-environmental buffering, protection of acid-labile ingredients, or pH-independent release of weak acid drugs. In this study, the influence of sodium citrate on the release kinetics, gel layer formation, internal gel pH and drug release mechanism was investigated in HPMC 2910 and 2208 (Methocel E4M and K4M) matrices containing 10% felbinac 39% HPMC, dextrose and sodium citrate. Matrix dissolution at pH 1.2 and pH 7.5 resulted in complex release profiles. HPMC 2910 matrices exhibited biphasic release, with citrate increasing the immediate release phase (<60 min) and reducing the extended release. HPMC 2208 matrices were accelerated, but without the loss of extended release characteristics. Studies of early gel layer formation suggested gel barrier disruption and enhanced liquid penetration. pH modification of the gel layer was transitory (<2 h) and corresponded temporally with the immediate release phase. Results suggest that in HPMC 2910 matrices, high initial citrate concentrations within the gel layer suppress particle swelling, interfere with diffusion barrier integrity, but are lost rapidly whereupon drug solubility reduces and the diffusion barrier recovers. These Hofmeister or osmotic-mediated effects are better resisted by the less methoxylated HPMC 2208.

Hydrothermal synthesis of 2D ordered macroporous ZnO films

The ZnO films with two-dimensional ordered macroporous structure were successfully fabricated through hydrothermal crystal growth of ZnO on the ZnO substrate covered with a monolayer of polystyrene (PS) spheres as template. The precursor solution of hydrothermal crystal growth of ZnO were prepared by equimolar solution of Zn(NO3)2·6H2O and hexamethylenetramine (HMT). The confinement effect of the PS spheres template on the growth of ZnO nanorods and the influence of sodium citrate on the crystal growth of ZnO had been studied. The film surface morphology and the preferential growth of ZnO crystal were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Also, the photoluminescence spectrum of ZnO films had been measured, and the corresponding mechanism was discussed.

The modes of glucose action on photosynthesis of Spirulina platensis (Nordst.) Geitl. (Cyanophyta) as revealed by chlorophyll fluorescence analysis

The effects of a) glucose, b) mannose and 2-deoxyglucose (glucose analogues capable of triggering hexokinase-mediated photosynthesis repression) and c) sodium citrate on chlorophyll fluorescence parameters of the blue-green alga Spirulina platensis (Nordst.) Geitl. were investigated. The addition of glucose evoked, at first, the lowering of all photochemical fluorescence quenching parameters (FV/FM, FV'/FM', qP and ΦPS II). The decrease correlated with glucose concentration. The inhibition of photochemical activity relaxed after the third day of the experiment, perhaps, as the consequence of glucose utilization. If the concentration of glucose in the cultural medium was high enough (50 mM), on the seventh day all the indices of photochemical quenching began to diminish again, at which time qP reduction was more significant than that for FV'/FM'. The relief of glucose repressive effects was light-dependent. Glucose analogues caused the decrease in only one photochemical quenching parameter, qP. Unlike mannose, the effect of 2-deoxyglucose was more pronounced and did not weaken till the end of experiments. Nonphotochemical quenching fluorescence parameters (qN and NPQ) were also reduced under monosaccharide treatment. The influence of sodium citrate on chlorophyll fluorescence parameters was negligible. Therefore, the multiplicity of glucose effects in the course of inhibition of S. platensis photosystem II activity was demonstrated, while hexokinase-dependent repression mechanism was playing only a partial role and resulting in the blocking of electron flow from photosystem II reaction centers down the electron transport chain.

Influence of sodium citrate and potassium–sodium tartrate on gelation of low-methoxyl amidated pectin

The influence of sodium citrate and potassium–sodium tartrate on Ca 2+ induced low-methoxyl amidated pectin gelation has been investigated. Dispersions with pectin concentration 1%, soluble solids (sucrose) 30% and pH 4 have been prepared. The measurements have been performed with a HAAKE VT 550 viscotester. The range of Ca 2+ concentrations at which “good” gels can be formed is very narrow in cases when gels have been prepared without salt or when NaCl has been used. This range is expanded and shifted to larger Ca 2+ concentration in the presence of sodium citrate and potassium–sodium tartrate. These salts “weaken” the gels (module of elasticity G and rupture stress τ 0 decrease with increasing salt’s concentration) and make them more elastic (rupture strain γ 0 increases). The effect of the above-mentioned salts on gel restoring after mechanical destruction (shearing) or melting has been investigated. Both salts make regelling significantly difficult in the case when the gels have been mechanically destroyed. Gels become thermoreversible (they can be melted) and their restoration after melting depends on the salt’s concentration.

Involvement of transferrin in the uptake of 67Ga in inflammatory and normal tissues

The results from gel chromatography and electrophoresis showed that 67Ga is exclusively bound with transferrin both in vitro and in vivo, but high concentrations of sodium citrate strongly inhibited the binding of 67Ga to transferrin. The influence of sodium citrate on the uptake of 67Ga into inflammatory and normal soft tissues was also investigated. Sodium citrate decreased the uptake of 67Ga into the liver and spleen, but had no influence on the uptake of 67Ga into inflammatory tissue. These results suggest that the uptake of 67Ga into normal soft tissues occurs in a transferrin-bound form but into inflammatory tissue in an unbound form.

Characteristics of polymorphonuclear leukocyte infiltration into the alkali burned eye and the influence of sodium citrate

Polymorphonuclear leukocytes (PMNs) are considered to play a central role in the corneal ulceration process subsequent to an alkali burn. We have described the time course of PMN infiltration into the ocular tissues following an alkali burn. In addition, we examined the effect of sodium citrate upon the accumulation of PMNs in the alkali burned cornea. The accumulation of PMNs into the cornea and iris-ciliary body was quantified by measuring myeloperoxidase (MPO), an enzyme marker for these inflammatory cells. Leukocytes in aqueous humor aspirates and corneal washes were counted directly under a microscope. In the alkali burned cornea, we found an initial transient, yet substantial, infiltration of PMNs, peaking at about 12–24 hr and limited to the peripheral cornea; this subsided by about 72 hr. By 14 days, the MPO activity, and hence the number of leukocytes, had risen again, and by 21 days the level had increased by several fold. Qualitatively similar biphasic patterns of leukocyte infiltration were observed in the iris-ciliary body and aqueous humor. Leukocyte numbers in corneal washes only increased between 4–24 hr following the alkali burn. The exceptionally high degree of leukocyte infiltration into the cornea at 21 days corresponded with the presence of ulceration. Topical administration of sodium citrate (10%) inhibited the early and late phase of PMN accumulation in the alkali burned cornea, i.e. at 24 hr (−63%) and 21 days (−92%). The inhibition of PMN infiltration by sodium citrate correlates with the reduced corneal ulceration observed following treatment with this compound.

Influence of sodium citrate on the heat stability of buffalo milk and its concentrate

The influence of added sodium citrate (0.05%, 0.10% and 0.15%) on the heat stability (at 130°C) of buffalo milk and its 2:1 concentrate was determined. It was observed that added citrate caused a decrease in the heat stability of buffalo milk and its concentrate which was statistically significant and progressive as the concentration of citrate was increased. The decrease in the heat stability of buffalo milk and its concentrate due to the addition of citrate may be attributed to an increase in pH to a level of minimum stability. However, with an optimum adjustment in the pH, sodium citrate may be used for the stabilization of buffalo milk and its concentrate. It was also observed that, in all samples of buffalo milk, the normal pH was on the alkaline side of the pH of maximum heat stability.

Influence of Sodium Citrate on the Setting of Plaster of Paris

Influence of Sodium Citrate on the Setting of Plaster of Paris