Amino acids, ferritin, and mineral oxalates in edible Salicornia patula young shoots: Chemical characterization and nutritional implications.

Improving the Sustainability of Magnesium Oxalate Cements Using Clay and Calcium Sulfoaluminate Clinker

Enhancing magnesium oxalate cements with copper slag and silica fume

CO2 emissions and energy consumption associated with ordinary Portland cement production have increased the urgency for the development of alternative construction materials. Reactive magnesia cement (RMC) has been widely studied in the recent years due to the lower calcination temperature used during its production and its ability to permanently sequester CO2. In addition to the calcination of magnesite, reactive MgO, the main component of RMC, can also be synthesized from reject brine, which is rich in Mg2+. However, the presence of other components such as calcium in reject brine leads to the precipitation of other mineral phases together with Mg(OH)2, thereby reducing the purity of the final product. With the goal of improving the purity and yield of MgO synthesized at the end of this process, this study proposed a selective precipitation approach under a controlled pH. An optimum condition was determined for the synthesis of magnesium oxalate dihydrate with an ultra-high purity of 99.6 % and a high magnesium recovery rate of 94.1 %. Reactive MgO with a specific surface area of 30.2 m2/g was obtained after the calcination of the synthesized magnesium oxalate dihydrate at 700 °C for 2 h, which was higher than some of the commercially available MgO powders.

Influence of oxalic acid on the corrosion behavior of AZ91D magnesium alloy in deionized water

Magnesium oxalate cement, a novel alternative to portland cement, can be made at room temperature by reacting dead-burned magnesia and salts of oxalic acid. Since oxalic acid can be made using captured carbon dioxide, oxalate cements may even be carbon negative. However, emissions related with the decarbonation of magnesite at high temperatures make this hard to achieve. This study investigates the effect of replacing magnesia with granulated blast furnace slag on some physical and mechanical properties, as well as the mineralogy and microstructure of oxalate cements. Whewellite and Weddellite are identified when slag is used, in addition to Glushinskite which forms from magnesia. Slag-only mortars undergo faster but less complete reactions and show lower resistance to water than their magnesium oxalate counterparts. An equal-part combination of dead-burned magnesia and slag gives the highest 28-d strength (> 35 MPa), pH~7, and high water resistance.

Third order non-linear optical properties of cadmium magnesium oxalate crystals grown by silica gel technique

Synthesis of highly active solid base catalysts of SrO-ZrO2 and SrO-SiO2 by solid–liquid interface reactions of hydrated strontium hydroxide with metal alkoxides

Abstract BACKGROUND AND AIMS Several epidemiological studies have observed an increased risk for nephrolithiasis in patients affected by non-alcoholic fatty liver disease (NAFLD). However, the urinary lithogenic risk profile for patients with NAFLD is currently unknown. METHOD We systematically analysed the urinary metabolic profile of patients affected by NAFLD and liver cirrhosis (LC), followed at the hepatology outpatient clinic of our institution, compared to healthy individuals. A complete metabolic work-up for kidney stone disease was performed in all subjects. Multivariable linear regression models adjusted for age, sex, body mass index, eGFR and diabetes, were applied to assess differences in urinary lithogenic risk factors between healthy individuals and patients affected by NAFLD and LC. RESULTS A total of 42 patients and 12 healthy individuals were included in the analysis. No differences in age, sex and BMI were found among patients affected by NAFLD and LC, whereas the latter were more diabetic (71.4% versus 14.3%). After adjusting for multiple confounders, patients with NAFLD and LC had lower urinary magnesium (−55 mg/24 h; 95% CI −104, −6; P = 0.03 and −63 mg/24 h; 95% CI −121, −6; P = 0.03, respectively) and borderline oxalate (−1.21 mg/24 h; 95% CI −2.42, −0.01; P = 0.05 and −1.42 mg/24 h; 95% CI −2.79, −0.04; P = 0.04, respectively) excretions, compared with healthy controls. Compared with LC patients, NAFLD patients showed higher urinary ammonia (539 mEq/24 h; 95% CI 245, 833; P < 0.01), ammonia/net acid excretion ratio (0.40; 95% CI 0.18, 0.62; P < 0.01), urine pH (1.16; 95% CI 0.44, 1.88; P = 0.05) and lower urinary uric acid excretion (−210 mg/24 h; 95% CI −419, −0.29; P < 0.01) and titratable acidity (−9.7 mEq/24 h; 95% CI −19.0, −0.4; P = 0.04). CONCLUSION Altered urinary ammonia and magnesium excretions seems to be involved in the higher risk for stone formation found in patients with NAFLD. More studies are needed to investigate stone phenotypes and renal handling of ammonia in this setting.

One-step combustion synthesis of C/MgO composite powders with MgO nanofibers

ABSTRACT We report theoretical and experimental investigations on the structures of strontium and magnesium oxalates, and corresponding Raman spectra at high pressure. These systems have shown progress in the generation of CO2 and in the synthesis of energetic doped polymeric carbon monoxide after X-ray irradiation and simultaneous application of high pressure. Density functional perturbation theory (DFT) was used to calculate the zone center optical phonons in monoclinic and triclinic strontium oxalate, and the ambient triclinic phase of magnesium oxalate. Vibration modes were also determined in terms of atomic displacements for both compounds. The simulations were compared to experimental Raman spectra in an effort to elucidate the details of the phase transition between monoclinic and triclinic phases. Additional phonon dispersion calculations of the compounds were performed to gain better insight into the dynamic phase stability in strontium and magnesium oxalates under high pressure.

to evaluate urinary biochemical alterations related to urolithogenesis processes after sleeve gastrectomy (SG). : prospective study with 32 individuals without previous diagnosis of urolithiasis who underwent SG. A 24-h urine test was collected seven days prior to surgery and at 6-month follow-up. The studied variables were urine volume, urinary pH, oxalate, calcium, citrate, and magnesium and calcium oxalate super saturation (CaOx SS). patients were mainly women (81.2%), with mean age of 40.6 years. Mean pre- and postoperative BMI were 47.1 ± 8.3 Kg/m2 and 35.5 ± 6.1 Kg/m2, respectively (p<0.001). Urine volume was significantly lower at the postoperative evaluation in absolute values (2,242.50 ± 798.26 mL x 1,240.94 ± 352.39 mL, p<0.001) and adjusted to body weight (18.58 ± 6.92 mL/kg x 13.92 ± 4.65 mL/kg, p<0.001). CaOx SS increased significantly after SG (0.11 ± 0.10 x 0.24 ± 0.18, p<0.001). Moreover, uric acid levels were significantly lower at the postoperative evaluation (482.34 ± 195.80 mg x 434.75 ± 158.38 mg, p=0.027). Urinary pH, oxalate, calcium, citrate, and magnesium did not present significant variations between the pre- and postoperative periods. SG may lead to important alterations in the urinary profile. However, it occurs in a much milder way than that of RYGB.

In this paper, the thermal decomposition process of magnesium acetate, Mg (CH3COO)2·4H2O, in nitrogen atmosphere was studied by thermal analysis methods, and the solid products after thermal decomposition were analyzed by XRD, FE-SEM and EDS. The results show that the thermal decomposition process of magnesium acetate went through four steps: the first step was the dehydration of magnesium acetate to produce anhydrous magnesium acetate; the second step was the conversion of anhydrous magnesium acetate to magnesium oxalate; the third step was magnesium oxalate to magnesium carbonate, and the final step was magnesium carbonate to magnesium oxide.

Structurally improved MgO adsorbents derived from magnesium oxalate precursor for enhanced CO2 capture

Abstract Hydrogen adsorption/desorption properties of magnesium oxalate and calcium oxalate (M(ox); M = Mg2+ and Ca2+) were measured at selected temperatures between 77 K and 200 K. The hydrogen uptake amounts were 0.037 wt% for Mg(ox) and 0.147 wt% for Ca(ox) at 87 K, 0.15 MPa. Hydrogen adsorption enthalpy for Ca(ox) was estimated as −16 ∼ −13 kJ/mol-H2, which indicated the contribution of charge-transfer interaction between Ca2+ and H2 molecule. Limited hydrogen uptake for both Mg(ox) and Ca(ox) were attributed to the intermolecular interaction between M2+ and oxygen atoms of surrounding M(ox) molecules.

Objective: Vaginal calculus is an unusual finding. In this study we describe a case of primary vaginal calculus in a rather rare urogenital anomaly- Obstructed hemivagina with ipsilateral renal agenesis (OHVIRA) syndrome. This syndrome is shrouded in controversies. Here we present a mini review about vaginal calculus and theory of embryological development of female genital tract as related to OHVIRA syndrome. Case: A 50 years-old unmarried lady with primary amenorrhoea presented with pain abdomen. She was found to have calculus in the pelvis by x-ray which was thought to be bladder calculus initially. On local examination the vaginal opening was absent. Imaging studies such as NCCT and MRI confirmed that it is a vaginal calculus, located below the uterine cervix, with absent right kidney. She was diagnosed with OHVIRA syndrome with colpolithiasis. On laparotomy she was detected to have unicornuate uterus with absence of right Mullerian structures. The calculus occupied the whole of upper part of vagina, which was a blind pouch. The patient underwent total abdominal hysterectomy, left salpingo-ophorectomy with removal of calculus after opening the vaginal vault. Postoperative recovery was uneventful. Chemical analysis of the calculus revealed calcium magnesium oxalate which is of hematic origin. Keywords: Primary vaginal calculus, Mullerian duct anomaly, Obstructed hemivagina, OHVIRA syndrome, Herlyn-Werner-Wunderlich syndrome.

The purpose of the study was to synthesize MgO nanomaterials using sol-gel method with ethanol as solvent and to perform structural analysis of the products. Mg-oxalate was initially prepared prior magnesium acetate. Magnesium acetate dissolved in ethanol, and the oxalic acid added to adjust pH until gel phase formed. The gel was heated at 100 C for 24 hours to produce magnesium oxalate solids. Solids was sieved using ±150 mesh then annealed at 550 C for 6 hours to produce MgO nanomaterial. The magnesium oxalate was characterized using&#13;\nFT-IR, XRD, and SEM. FT-IR peak at 3408.22 cm-1; 1709.35 cm-1; 1375.39 cm-1; 830.32 cm-1; 420.48 cm-1, and the XRD peak 17.95o ; 22.97o ; 25.02o ; 27,94o ; 35.10o ; 37,63o ; 44.16o were characteristic of Mg-oxalate. Meanwhile, FT-IR band at 1030.24 cm-1; 2358.94 cm-1; 1627.92 cm-1; 1417.66 cm-1; 437.84 cm-1, and XRD peak at 38.92o ; 43.3o 56.02o ; 62.64o ; 74.88o and 79.04o shows characteristic of MgO nanomaterial. Structure analysis shown the MgO nanomaterials has an average crystal size 8.11 nm, and lattice length 21.21 nm. The values of strain, stress, energy density crystal and dislocation density of the MgO are 5.3 x 10-5 MPa, 32.97 MPa, 154.81 J/nm2 , 1.52 x 10-3 nm-2 respectively. Morphologically the MgO nanomaterial produced is cubic.

Magnesium plays numerous vital roles in human's body. It is known as a protective factor in stone formation by binding to oxalate in the intestinal and urinary system, and decreasing its absorption and crystallization, respectively. Due to controversies about the association between the 24-h urine magnesium and other urine metabolites in different studies, this study was designed to find a clear answer to this question. In this retrospective cross-sectional study, data from 24-h urinalysis of the calcium stone-forming (CSF) patients were assessed. The correlation between 24-h urine (24-U) magnesium to creatinine ratio (Mg/Cr) with other 24-U metabolites to creatinine ratio was assessed, using Spearman correlation test. The association between 24-U magnesium and 24-U oxalate was also studied in a multivariate logistic regression model. Among 965 patients, the level of Mg/Cr showed a direct association with all other 24-U metabolite to Cr ratio (p-value < 0.001 for all analyses). The result of multivariate regression analysis showed that the higher quartile of 24-U oxalate (> 47mg/24h) increased the odds of 24-U magnesium more than 75mg/24h (data median) (OR 1.89, 95% CI 1.14-3.13) comparing with the lower quartile of 24-U oxalate (≤ 26mg/24h). In a routine dietary habit, since rich sources of magnesium contain a high amount of oxalate at the same time, it is not surprising that magnesium level in 24-h urinalysis showed a direct association with 24-h urine oxalate.

Nanostructured MgO sorbents show promise for intermediate-temperature CO2 capture from post-combustion flue gas stream. However, their CO2 capture behaviors can be affected by the magnesium precursors applied for sorbent synthesis. To screen potential precursors for fabricating excellent CO2 trappers, MgO nanoparticles (NPs) were synthesized by calcining several organometallic precursors, including magnesium ethoxide, magnesium acetate tetrahydrate, magnesium oxalate dehydrate, magnesium lactate dihydrate, magnesium citrate nonahydrate, and magnesium gluconate hydrate. The precursors and MgO NPs were characterized by thermogravimetric analysis, X-ray diffraction, N2 adsorption–desorption, field emission scanning electron microscopy, and CO2 temperature-programmed desorption. A fixed-bed reactor was used to evaluate the CO2 capture performances of the MgO NPs in a simulated flue gas stream. The effect of organometallic precursors on CO2 capture behaviors of the sorbents was further demonstrated. Results in...

Mesoporous activated carbons synthesized by pyrolysis of waste polyester textiles mixed with Mg-containing compounds and their Cr(VI) adsorption