Oxalic Solution Research Articles

Improved electrochemical properties of the Li3V2(PO4)3 cathode material synthesized from a V(III) precursor

The choice of precursors can significantly influence the properties of synthesized materials. Here, we describe the effect of two different valence states of vanadium precursors, i.e., V(III) and V(IV), on the electrochemical properties of the resulting Li3V2(PO4)3/C composite synthesized through a sol−gel route. To obtain a homogeneous V(III) solution compatible with the aqueous sol−gel synthesis route, we used a facile and straightfoward electrolysis method to reduce V(IV) into V(III) in the oxalate solution. After the sol−gel and sintering processes, the resulting Li3V2(PO4)3/C composite synthesized from V(III) presents higher specific capacity and better cycle performance at different charging/discharging rates, compared with the composite prepared from V(IV). The improved electrochemical performance of the former is likely due to the more straightforward phase formation process for V(III) than V(IV) precursor in the synthesis.

Usefulness of dark field microscopy (DFM), IGM ELISA and microscopic agglutination test (MAT) for the early diagnosis of acute leptospirosis

Usefulness of dark field microscopy (DFM), IGM ELISA and microscopic agglutination test (MAT) for the early diagnosis of acute leptospirosis - IJMR- Print ISSN No: - 2394-546X Online ISSN No:- 2394-5478 Article DOI No:- 10.18231/j.ijmr.2019.036, Indian Journal of Microbiology Research-Indian J Microbiol Res

Preparation of Zirconium-89 Solutions for Radiopharmaceutical Purposes: Interrelation Between Formulation, Radiochemical Purity, Stability and Biodistribution.

Zirconium-89 is a promising radionuclide for nuclear medicine. The aim of the present work was to find a suitable method for obtaining zirconium-89 solutions for radiopharmaceutical purposes. For this purpose, the ion exchange behavior of zirconium-89 solutions was studied. Radio-TLC (thin layer chromatography) and biodistribution studies were carried out to understand speciation of zirconium-89 complexes and their role in the development of new radiopharmaceuticals. Three methods of zirconium-89 isolation were studied using ZR (hydroxamate) and Chelex-100 resins. It was found that ZR-resin alone is not enough to obtain stable zirconium-89 formulations. An easy and effective method of reconstitution of [89Zr]Zr-oxalate to [89Zr]Zr-citrate using Chelex-100 resin was developed. Developed procedures allow obtaining [89Zr]Zr-oxalate (in 0.1 M sodium oxalate solution) and [89Zr]Zr-citrate (in 0.1–1.0 M sodium citrate solution). These solutions are perfectly suitable and convenient for radiopharmaceutical purposes. Our results prove [89Zr]Zr-citrate to be advantageous over [89Zr]Zr-oxalate. During evaluation of speciation of zirconium-89 complexes, a new TLC method was developed, since it was proved that there is no comprehensive method for analysis or zirconium-89 preparations. The new method provides valuable insights about the content of “active” ionic form of zirconium-89. The interrelation of the chromatographic behavior of zirconium-89 preparations and their biodistribution was studied.

In vitro antilithiatic activity of the hydro-alcoholic extract of Cinnamomum zeylanicum Blume bark on calcium oxalate crystallization

ObjectiveThe study examines the effect of the hydro-alcoholic extract of Cinnamomum zeylanicum Blume bark on crystallization of calcium oxalate. MethodsThe antilithiatic effect of various concentrations of the hydro-alcoholic extract of C. zeylanicum was investigated at various stages of stone formation, using Cystone as a standard reference drug. The effect on calcium oxalate crystallization was evaluated by measuring the change in turbidity over time, during crystal nucleation, growth and aggregation, in the metastable solution of calcium chloride and sodium oxalate. The slope from the change in turbidity over time was measured using a spectrophotometer at 620 and 214 nm in respective tests. The inhibition rate was estimated by comparing turbidity in the presence and absence of extract. Crystals formed under experimental conditions were observed under a light microscope, and number and shape of the crystals were assessed in a randomly selected field. Phytochemical analysis and high-performance thin-layer chromatography of the extract was also carried out. ResultsC. zeylanicum significantly reduced crystal nucleation at concentrations of 4, 8 and 10 mg/mL (P < 0.001). The inhibition percentage of crystal growth was between 28.30% and 92.46% in the presence of C. zeylanicum extract and from 20.76% to 64.15% with various concentrations of Cystone. The maximum inhibition of crystal growth was obtained from C. zeylanicum at 2 mg/mL (92.46%). Microscopic examination revealed a reduction in the number and size of crystals. In the aggregation assay, the inhibition percentage of C. zeylanicum was between 16.27% and 100%, while Cystone was from −214.68% to 100% at different concentrations. The highest (100%) inhibition of aggregation was found at 4 mg/mL of both the test and standard drugs. ConclusionWe found that C. zeylanicum hydro-alcoholic extract has notable inhibitory effects on various stages of crystallization, in terms of turbidity of solution, as well as the crystal size, number and morphology.

Integrated treatment of tailing material for the selective recovery of uranium, rare earth elements and heavy metals

Processed ores may contain substantial amounts of residual valuable metals. In the case of the mining wastes issued from the exploitation of gibbsite bearing shale ore in the Southwestern Sinai, the characterization of the residue shows the presence of uranium, rare-earth elements (REEs), aluminum and zinc that can be valorized. Pug leaching at 120 °C with an acid consumption of about 200 kg H2SO4 per ton of ore succeeded in leaching more than 94% of U(VI) and REEs (in addition to substantial amounts of Al(III) and Zn(II)). A series of selective precipitation steps allowed successively recovering (almost quantitatively) Zn(II), Fe(III) and Al(III). In a second step, a magnetic resin has been used for enriching the pregnant leaching solution (by a factor close to 19) through sorption/desorption steps. In the last stage of the process, REEs were recovered by selective precipitation using 25% (w/w) oxalate solution at pH 1.5, while uranium was fully recovered by precipitation with NaOH at pH 9. Energy dispersive X-ray analysis performed on the different precipitates showed purity grades systematically superior to 93%.

Evaluation of Antiurolithiatic activity of Polyherbal formulation (Lithout Tablets) by In-vitro inhibition of Calcium Oxalate Crystallization

The present study is to determine the inhibitory effect of prepared Lithout tablets for their antiurolithiatic activity. In this study we used the turbidimetric model. In this model the inhibitory effect of Lithout tablets were determined by adding solution of different concentrations of prepared polyherbal formulation in the solution of calcium chloride and sodium oxalate. The absorbance of this solution was taken at 620 nm for each minute till 10 minutes. The percentage inhibition of calcium oxalate crystallization was calculated. Study reveals that prepared Lithout tablets effectively reduce the crystallization of calcium oxalate in the solution. And thus it was concluding that the Lithout tablets produce significant antiurolithiatic activity.

Visible Light Driven Organic Pollutants Degradation with Hydrothermally Carbonized Sewage Sludge and Oxalate Via Molecular Oxygen Activation.

Converting sewage sludge into functional environmental materials has become an attractive sewage sludge disposal route. In this study, we synthesize a sewage sludge-based material via a facile one-pot hydrothermal carbonization method and construct a visible light molecular oxygen activation system with hydrothermally carbonized sewage sludge (HTC-S) and oxalate to degrade various organic pollutants. It was found that iron species of HTC-S could chelate with oxalate to generate H2O2 via molecular oxygen activation under visible light, and also promote the H2O2 decomposition to produce •OH for the fast organic pollutants degradation. Taking sulfadimidine as the example, the apparent degradation rate of HTC-S/oxalate system was almost 5-20 times that of iron oxides/oxalate system. This outstanding degradation performance was attributed to the presence of iron-containing clay minerals in HTC-S, as confirmed by X-ray diffraction measurements and Mössbauer spectrometry. In the oxalate solution, these iron-containing clay minerals could be excited more easily than common iron oxides under visible light, because the silicon species strongly interacted with iron species in HTC-S to form Fe-O-Si bond, which lowered the excitation energy of Fe-oxalate complex. This work provides an alternative sewage sludge conversion pathway and also sheds light on the environmental remediation applications of sewage sludge-based materials.

The Long Pentraxin PTX3 Is an Endogenous Inhibitor of Hyperoxaluria-Related Nephrocalcinosis and Chronic Kidney Disease.

The long pentraxin 3 (PTX3) exerts a variety of regulatory functions in acute and chronic tissue inflammation. In particular, PTX3 acts as an opsonin for a variety of pathogens and endogenous particles. We hypothesized that PTX3 would exhibit opsonin-like functions toward calcium oxalate crystals, too, and inhibit crystal growth. This process is fundamental in kidney stone disease as well as in hyperoxaluria-related nephrocalcinosis, the paradigmatic cause of chronic kidney disease (CKD) in children with primary hyperoxaluria type I due to genetic defects in oxalate metabolism. Direct effects of PTX3 on calcium oxalate crystals were investigated in chemico by adding recombinant PTX3 to supersaturated calcium and oxalate solutions. PTX3, but not isomolar concentrations of albumin, dose-dependently inhibited crystal growth. In vivo, the PTX3 protein was undetectable in tubular epithelial cells and urine of wild-type mice under physiological conditions. However, its levels increased within 3 weeks of feeding an oxalate-rich diet, an exposure inducing hyperoxaluria-related nephrocalcinosis and CKD in selected mouse strains (male and female C57BL/6N and male Balb/c mice) but not in others (male and female 129SV and CD-1, male and female Balb/c mice). Genetic ablation of ptx3 in nephrocalcinosis un-susceptible B6;129 mice was sufficient to raise the oxalate nephropathy phenotype observed in susceptible strains. We conclude that PTX3 is an endogenous inhibitor of calcium oxalate crystal growth. This mechanism limits hyperoxaluria-related nephrocalcinosis, e.g., in primary or secondary hyperoxaluria, and potentially also in the more prevalent kidney stone disease.

Poly(2-chloroaniline) and poly(aniline-co-2-chloroaniline) films on ZnFe alloy plating

PurposeThe purpose of this paper is to evaluate and compare the protective, anticorrosion behaviors and electrochemically synthesis of poly(2-chloroaniline) (PCANI) and poly(2-chloroaniline-co-aniline) P(CANI-co-ANI) films on thin zinc–iron plated carbon steel (CS).Design/methodology/approachZinc–iron (ZnFe) alloy plating was successfully achieved on CS applying 3 mA constant current value. The PCANI and P(CANI-co-ANI) films on ZnFe-plated CS electrode were synthesized by cyclic voltammetry technique using monomer(s) containing 0.20 M sodium oxalate solution. The CS/ZnFe electrodes with and without PCANI or P(CANI-co-ANI) films were characterized using SEM and anodic linear sweep voltammograms. The anticorrosive behaviors of uncoated and coated electrodes were studied in 3.5 per cent NaCl solution by corrosion techniques which include open circuit potential measurements, the anodic polarization curves and alternative current electrochemical impedance spectroscopy (EIS) technique.FindingsThe protection efficiency values (E per cent) for CS/ZnFe, ZnCS/ZnFe/PCANI and CS/ZnFe/P(CANI-co-ANI) electrodes were calculated as 71.05, 84.53 and 92.79, respectively, after 168 h of immersion time. The results showed that P(CANI-co-ANI) coating on ZnFe-plated CS electrode exhibited higher corrosion resistance and provided better barrier property in comparison with PCANI coating and ZnFe alloy plating, in longer exposure time.Originality/valueA number of reports on the synthesis and characterization of PANI have appeared in the literature during the past decade, but there is no such publication of PCANI. At the same time, the synthesis of PCANI onto the surface of metal alloy coating being the first of this kind, no such proceedings have been reported in the literature so far.

Nanoporous alumina thin films with interpenetrated structure via alternating voltage anodization

Ordered nanoporous alumina thin films with interpenetrated structures were prepared via alternating voltage (AV) anodization of Al foils in oxalic acid aqueous solutions. Anodization at different time periods was systematically investigated to better understand the formation process of this unique structure. Meanwhile, the corresponding current-time transient curves were recorded to monitor the formation process. Based on the obtained results, the possible formation process of porous alumina thin films with interpenetrated structure was discussed.

High Resolution ATR μ-FTIR to map the diffusion of conservation treatments applied to painted plasters

Here we demonstrate the extension of applicability of high resolution Attenuated Total Reflection Fourier transform infrared μ-mapping (ATR μ-FTIR) to the investigation of the diffusion of a conservation treatment, ammonium oxalate, within painted plasters. The method demonstrates its potentiality in situations where high lateral resolution is required and the compounds are not easily detectable with conventional analytical techniques. It was applied successfully to explore the interaction between ammonium oxalate solutions and the carbonatic matrix at the microscale. The reaction of the carbonatic aggregate particles was assessed as well as the influence of the treatment parameters on the penetration depth. High resolution ATR μ-FTIR represents a new spectroscopy imaging modality expanding the portfolio of chemically specific analytical tools.

The mechanisms of corrosion inhibition of hot-dip galvanized steel by vanadyl oxalate: A galvanic corrosion investigation supported by XPS

The mechanisms of corrosion inhibition of hot-dip galvanized steel by vanadyl oxalate were studied using galvanic corrosion approach and XPS. The partial separation of electrode reactions was achieved using a split cell design. Injection of vanadyl oxalate solution to the cathode side of split cells significantly reduced the galvanic current, whereas injection to the anode side had little effect on the galvanic current. V(IV) inhibits oxygen reduction by a mechanism involving V(IV) reduction to V(III) and formation of V(III) layers on the cathode. V(IV) acts as a cathodic inhibitor, due to V(III) layer occupation of active sites for oxygen reduction.

Solid State Chemistry of Ten-Fold Coordinate Thorium(IV) Complexes with Oxalates in the Presence of Ammonium and Hydrazinium Ions

Double and triple thorium oxalates have been synthesized by successive evaporation of a solution of thorium nitrate, ammonium, or hydrazinium oxalate and hydrogen peroxide. Compounds M6Ca2Th2(C2O4)9·nH2O (M = NH4+, N2H5+) (1) were first accidentally obtained due to the unexpected presence of calcium as impurities in the thorium nitrate used. Further evaporation led to the M2Th2(C2O4)5·nH2O (M = NH4+, N2H5+) (2) precipitation. After an additional evaporation of 2 weeks, compounds (2) transform into M4Th(C2O4)4·nH2O (M = NH4+, N2H5+) (3). In the three compounds, thorium is coordinated by five bidentate oxalate ions. In (1) Th(C2O4)5 entities share an oxalate ion to form dimeric units further connected by Ca(C2O4)5 (M = NH4+) or Ca(C2O4)5(H2O) (M = N2H5+) entities to build three-dimensional (3D) frameworks. Compounds (2) exhibit a 3D honeycomb thorium oxalate framework. Compounds (3) contain chains of oxalate-shared Th(C2O4)5 entities, whereas, in solution, the compound (NH4)2Th2(C2O4)5·1.5H2O (2) reacts with oxalate ions and turns into compound (NH4)4Th(C2O4)4·4H2O (3); in the solid state the chains of the compound (3) condense to form the 3D framework of the compound (2) and release solid ammonium oxalate.

New insights on protective treatments for marble by FIB-SEM

In this study, we investigated by FIB-SEM the microstructure of protective coatings formed by two inorganic treatments (namely, ammonium oxalate and ammonium phosphate solutions), with the aim of identifying the factors limiting the protective efficacy of the coatings and outlining possible improvement strategies. In the case of the oxalate treatment, the resulting layer of whewellite was found to contain vertical channels, which can allow water to reach the marble surface and trigger dissolution. Possible prevention of the formation of these channels by addition of a calcium source to the oxalate solution was attempted, but even micromolar additions led to rapid precipitation in the solution. In the case of the phosphate treatment, the resulting hydroxyapatite and octacalcium phosphate coating was found to be cracked and porous. To prevent cracks and pores, diminishing the ammonium phosphate concentration and adding ethanol to the solution were found to be effective strategies, as cracks were prevented and pores were reduced almost to zero. The resulting protective efficacy of the coating was found to be significantly improved, although still not perfect.

Preferential flow systems amended with biogeochemical components: imaging of a two-dimensional study

Abstract. The vadose zone is a highly interactive heterogeneous system through which water enters the subsurface system by infiltration. This paper details the effects of simulated plant exudate and soil component solutions upon unstable flow patterns in a porous medium (ASTM silica sand; US Silica, Ottawa, IL, USA) through the use of two-dimensional tank light transmission method (LTM). The contact angle (θ) and surface tension (γ) of two simulated plant exudate solutions (i.e., oxalate and citrate) and two soil component solutions (i.e., tannic acid and Suwannee River natural organic matter, SRNOM) were analyzed to determine the liquid–gas and liquid–solid interface characteristics of each. To determine if the unstable flow formations were dependent on the type and concentration of the simulated plant exudates and soil components, the analysis of the effects of the simulated plant exudate and soil component solutions were compared to a control solution (Hoagland nutrient solution with 0.01 M NaCl). Fingering flow patterns, vertical and horizontal water saturation profiles, water saturation at the fingertips, finger dimensions and velocity, and number of fingers were obtained using the light transmission method. Significant differences in the interface properties indicated a decrease between the control and the plant exudate and soil component solutions tested; specifically, the control (θ= 64.5∘ and γ= 75.75 mN m−1) samples exhibited a higher contact angle and surface tension than the low concentration of citrate (θ= 52.6∘ and γ= 70.8 mN m−1). Wetting front instability and fingering flow phenomena were reported in all infiltration experiments. The results showed that the plant exudates and soil components influenced the soil infiltration as differences in finger geometries, velocities, and water saturation profiles were detected when compared to the control. Among the tested solutions and concentrations of soil components, the largest finger width (10.19 cm) was generated by the lowest tannic acid solution concentration (0.1 mg L−1), and the lowest finger width (6.00 cm) was induced by the highest SRNOM concentration (10 mg L−1). Similarly, for the plant exudate solutions, the largest finger width (8.36 cm) was generated by the lowest oxalate solution concentration (0.1 mg L−1), and the lowest finger width (6.63 cm) was induced by the lowest citrate concentration (0.1 mg L−1). The control solution produced fingers with average width of 8.30 cm. Additionally, the wettability of the medium for the citrate, oxalate, and SRNOM solutions increased with an increase in concentration. Our research demonstrates that the plant exudates and soil components which are biochemical compounds produced and released in soil are capable of influencing the process of infiltration in soils. The results of this research also indicate that soil wettability, expressed as (cos θ)1∕2, should be included in the scaling of the finger dimension, i.e., finger width, when using the Miller and Miller (1956) scaling theory for the scaling of flow in porous media.

An experimental design approach for the separation of thorium from rare earth elements

As a part of technological evaluation of Eskişehir-Beylikahir thorium ore of Turkey, a novel study on the separation of thorium from oxalate concentrate including Th, La, Ce, Pr, Nd, Sm, Eu, Gd were carried out. As a first step, thorium-rare earth elements (REEs) oxalate concentrate was precipitated from nitric acid solution by the addition of 100% excess of oxalic acid amount necessary for stoichiometry. The concentrations of Th and REEs in the oxalate concentrate were chosen to simulate the oxalate intermediate product previously obtained from leach liqueur. Separation of thorium from REEs is mainly based on their significant solubility differences in ammonium oxalate solution. The dissolution conditions of thorium-REEs oxalate concentrate were investigated using central composite design (CCD) with three independent variables at five levels. The effect of independent variables such as contact time, amount of precipitate and the concentration of ammonium oxalate (AOX) solution on the thorium dissolution yield (%) were investigated. Analysis of variance (ANOVA) revealed that the effect of precipitate amount and the effect of ammonium oxalate concentration were found significant on the separation of thorium from Th-REEs concentrate. Probability F-value (F = 7 × 10−6) and correlation coefficient (R2 = 0.96) indicate that a proposed model fits the experimental data well. At the optimum conditions the thorium dissolution yield was achieved to 96.66 ± 2.16%.

PD03-09 ESTABLISHMENT OF A NEW METHOD TO EVALUATE THE PHAGOCYTIC ABILITY OF CALCIUM OXALATE MONOHYDRATE CRYSTALS BY MACROPHAGES

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology I1 Apr 2018PD03-09 ESTABLISHMENT OF A NEW METHOD TO EVALUATE THE PHAGOCYTIC ABILITY OF CALCIUM OXALATE MONOHYDRATE CRYSTALS BY MACROPHAGES Atsushi Okada, Hiroshi Takase, Teruaki Sugino, Rei Unno, Kazumi Taguchi, Shuzo Hamamoto, Ryosuke Ando, Keiichi Tozawa, and Takahiro Yasui Atsushi OkadaAtsushi Okada More articles by this author , Hiroshi TakaseHiroshi Takase More articles by this author , Teruaki SuginoTeruaki Sugino More articles by this author , Rei UnnoRei Unno More articles by this author , Kazumi TaguchiKazumi Taguchi More articles by this author , Shuzo HamamotoShuzo Hamamoto More articles by this author , Ryosuke AndoRyosuke Ando More articles by this author , Keiichi TozawaKeiichi Tozawa More articles by this author , and Takahiro YasuiTakahiro Yasui More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.275AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES It is recently being established that phagocytosis of crystals formed in the kidney by anti-inflammatory macrophages (M2-M&[phis]) inhibits urinary calculi formation, thus preventing stone formation. The aim of this study is to establish a new analytical method for quantifying the phagocytic ability of crystals by macrophages. METHODS Fluorescently labeled calcium oxalate monohydrate (f-COM) crystals were prepared by mixing Alexa Fluor 488 with 200 mM sodium oxalate solution and 200 mM calcium chloride dihydrate solution. After culturing mouse M&[phis]s (J774.1 and RAW264.7) for 24 h, f-COM crystals were exposed at 62.5 μg/cm2 (for 0, 6, and 24 h) and 133 μg/cm2 (for 24 h). At the defined times, the cells were washed with PBS to remove suspended f-COM crystals and then fixed with 4% paraformaldehyde. The cytoplasm of macrophages was stained with Phalloidin-iFluor 555 and the nucleus with 4',6-diamidino-2-phenylindole (DAPI). By using the IN Cell Analyzer 6000, which is an imaging cytometer, 100 fields of view of each well were scanned to quantify the signal intensity of f-COM crystals per cell and the number of phagocytic cells. RESULTS Imaging cytometry revealed f-COM crystals as green and cytoplasm and nucleus of macrophages as red and blue, respectively, in both cell lines. By quantitative analysis, COM signal intensity per cell showed significantly higher RAW 264.7 than J 774.1 at 6 and 24 h. These values also increased significantly with time and COM concentration dependence. Moreover, the COM signal positive cell number showed the same tendency. CONCLUSIONS We developed a method to accurately quantify COM crystals phagocytosed by macrophages. This method is expected to contribute to the development of future drugs that enhance the crystal phagocytic ability of macrophages. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e74-e75 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Atsushi Okada More articles by this author Hiroshi Takase More articles by this author Teruaki Sugino More articles by this author Rei Unno More articles by this author Kazumi Taguchi More articles by this author Shuzo Hamamoto More articles by this author Ryosuke Ando More articles by this author Keiichi Tozawa More articles by this author Takahiro Yasui More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Developing of Corrosion Resistance Nano Copper Oxide Coating on Copper Using Anodization in Oxalate Solution

Copper alloys are widely used in the manufacturing of heat transfer applications, this due to their excellent heat transfer properties. Copper contamination is one of the serious industrial problems in the boiler feed water system. This contamination commonly resulted from copper corrosion reactions in boiler feed water environment. The best way to reduce the copper contamination is by improving copper corrosion resistance. This research studies the developing of copper corrosion resistant by using anodization technique. The anodization experiments are conducted in oxalate solutions of concentrations from 0.1 to 0.5 M, at a temperature range from 24 to 0 ο C and applied potential from 7.5 to 9 V. Anodized coating analyzed using Field emission scanning microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction. Characterization results referred to the formation of copper oxide anodized coating with grain size range from 25 to 68 nm. The corrosion resistance of the anodized copper samples carried out in simulated boiler feed water. Results show that the corrosion resistance of the anodized samples was enhanced. The corrosion protection efficiencies for the anodized coating increased 86.2% and 74.5% in testing solutions contains 3.5% NaCl, and 2 mg/l NH3, respectively.

The study of the inhibitory effect of calcium oxalate monohydrate's crystallization by two medicinal and aromatic plants: Ammi visnaga and Punica granatum

Urinary lithiasis is a recurrent disease defined by the presence of calculi in the urinary tract. Most urinary calculi have as a major component calcium oxalate which occurs mainly in two crystalline forms: Calcium oxalate monohydrate (whewellite) and calcium oxalate dihydrate (weddellite). The target behind, this work is to study the inhibiting effect of the calcium oxalate's crystallization by the extract of the Ammi visnaga and the Punica granatum. The inhibition of crystallization has been studied in vitro with both the absence and the presence of the different concentrations of the extracts of the two plants. This study consists in measurement, with the UV-Visible spectrophotometer, the temporal evolution of the optical density at λ equal to 620nm corresponding to the formation of the crystals due to the mixing of metastable solutions of calcium and oxalate. The characterization of the crystals is carried out in parallel by both the Fourier transform infrared spectra (FT-IR) and the observation of the crystals with the help of an optical microscope. In this respect, the inhibition percentages were calculated from the turbidity slopes in the presence and absence of the extract. The results obtained were more effective, especially for Punica granatum with percentages of 97.8±0.12 and 83.46±1.34% against nucleation and aggregation, respectively, the order of Ammi visnaga was as follow: 73.25±0.81 and 59.44±3.3%. Thus, all correlation coefficients are greater than 0.95 and all coefficients of variation are less than 10%. The prevention and treatment of urinary lithiasis and especially in the case of recurrence by plants remains an alternative choice for medical methods. This study justified the efficacy of the plants Ammi visnaga and in particular Punica granatum against the crystallization of calcium oxalate. 3.

Cyanide-Free Silver Electrochemical Deposition on Copper and Nickel

Uracil was used as complexing agent to developp cyanide-free processes for silver deposition on copper and nickel substrates. We have highlighted that the molar ratio Ur/Ag+ between uracil and silver ions concentrations and the pH are crucial in the formulation of a stable and efficient bath and were found to be equal to 4 and 13.7 respectively. Silver was deposited in a single step on copper according to a three-dimensional nucleation mechanism while silver plating of nickel substrates was found to require an additionnal silver strike step. We worked out a choline chloride – oxalic acid DES-based silver solution which allowed to obtain bright, adherent and ductile silver coatings on Ni.