Oxalate Formation Research Articles

A reusable deep eutectic solvent for the regeneration of Li and Co metals from spent lithium-ion batteries

The prosperity of the lithium-ion battery industry has raised deep concerns about spent batteries. Recently, much attention has been focused on the development and advancement of lithium battery recycling. Deep eutectic solvents are efficient, environmentally friendly, and economical leaching solvents with great potential for the recovery of cathode materials from spent lithium-ion batteries. However, to date, deep eutectic solvents have been considered a disposable agent for lithium-ion battery recycling, resulting in organic waste after a single recycling. Here, we demonstrate a reusable deep eutectic solvent based on maleic acid (MA) and ethylene glycol (EG), designed to recycle LiCoO2 cathode materials from spent lithium-ion batteries. With a high loading capacity (59 g/L), the leaching efficiencies of Co and Li by MA:EG are 98.3 % and 98.4 % respectively. MA:EG can be refreshed by adding oxalic acid as a precipitant. Even after 4 cycles, the leaching efficiency of Co is still 90 % and the average recovery efficiency of Co products is over 96.5 %. Lithium is present in a high concentration and is also recovered in the form of oxalate. This work provides a novel and environmentally friendly recycling route that can economically and efficiently recover the valuable metals Li and Co from spent lithium-ion batteries.

Zanthoxylum acanthopodium: Microscopic, Chemical Characteristic, and anti- Enterococcus faecalis Effectivity of Fruit and Leaves Ethanol Extract

Oral and dental problems caused by microbial infections are one of the global health problems which reduce the quality of life for those affected. Enterococcus faecalis is a gram-positive bacterium, linked to oral cavity infections, which are usually managed by chlorhexidine as an oral antiseptic. However, there is a concern related to the occurrence of its resistance. Zanthoxylum acanthopodium has been reported to have antimicrobial activity, but its activity against E. faecalis has not yet been known. This research aims to observe microscopic characteristics by scanning electron microscopic, determining total flavonoid content, and identifying anti-E. faecalis effectiveness of fruit and leaf of Z. acanthopodium ethanol extract. Microscopic evaluation confirmed the presence of the epicarp and mesocarp in fruits, meanwhile three different forms of calcium oxalate existed in its leaf. Further evaluation showed that fruit ethanol extract (flavonoid content of 20.84 mg EQ/g) did not exhibit activity against E. faecalis. However, leaf ethanol extract (flavonoid content of 131.73 mg EQ/g) showed activity against E. faecalis with a coefficient value of 0.4 relative to chlorhexidine. This study demonstrated for the first time, antimicrobial effectiveness of Z. Acanthopodium leaves ethanol extract against E. faecalis.

Semicontinuous Process of Rare Earths Recovery from End-of-Life NdFeB Magnets on a Large Laboratory Scale

Hydrometallurgical methods for NdFeB recycling typically consist of several unit operations and require the extensive use of energy, water and chemicals which may negatively affect the applicability of these methods on an industrial scale. Based on the data from our previous studies, a simplified process of rare earth elements (REE) recovery from spent NdFeB magnets was developed further. The possibility of regenerating the leaching agent, as well as water recovery, in the process was investigated. This study also investigates a possibility of scaling up the recycling process developed on a laboratory scale. The leaching and precipitation stages were tested on a larger scale, where about 1 kg of end-of-life magnets was used as feed to the leaching step. In this study, end-of-life magnets were obtained from the manual disassembly of computer hard disc drives. After disassembly, the magnets were demagnetized, broken into pieces and fed to the leaching process. In the following step, rare earths were precipitated in the form of oxalates. The rare earths’ precipitation efficiency reached a maximum of 95.6%. The results showed that the co-precipitation of Fe highly depends on the amount of oxalic acid used as the precipitant. Smaller losses of Fe were achieved while using a stoichiometric amount of oxalic acid in relation to the REE present in the solution. At the end of the investigated process, rare earth oxalates were calcinated to oxides and their purity was investigated. The recirculation of a solution after oxalate precipitation and acid regeneration was tested with hydrochloric and sulfuric acids used as leaching agents. Solution recirculation was found to be possible only in the case of hydrochloric acid.

Recovery of Rare Earth Elements from the Leaching Solutions of Spent NdFeB Permanent Magnets by Selective Precipitation of Rare Earth Oxalates

After mechanical pre-treatment, the typical hydrometallurgical route of NdFeB magnet recycling starts with leaching in acidic solutions. However, due to the high concentration of iron ions in the leaching solution, the selective recovery of rare earths from the solution is challenging. In our work, the selective precipitation of rare earth oxalates as a potential separation method was proposed. The precipitation of neodymium oxalate was first tested on model solutions, which was then followed by experimental tests carried out on real solutions after the leaching of NdFeB magnets. The recovery of rare earths in the form of oxalates was investigated with the use of different amounts of oxalic acid in relation to its stoichiometric amount. The most efficient separation of rare earths was observed in the case where sulfuric acid was used for leaching. The use of oxalic acid in stoichiometric amounts resulted in the precipitation of about 93% of all rare earths present in the solution, whereas the concentration of Fe and other elements (Ni, Co, and B) practically did not change. An increase in oxalic acid of 20% and 40% more than the stoichiometric amount (100%) led to the increase in the precipitation efficiency of rare earths to 96.7% and 98.1%, respectively. However, the use of oxalic acid in a 1.4 ratio caused a 7% decrease in Fe concentration, which suggests Fe co-precipitation. In order to investigate a possibility of further increasing the separation of rare earths from iron, an additional method was tested, in which iron was first oxidized from Fe2+ to Fe3+ before the precipitation of rare earth oxalates.

Radiological features of nephrocalcinosis, a common but forgotten entity.

Nephrocalcinosis refers to calcium deposition in the form of calcium oxalate or calcium phosphate in the renal parenchyma and tubules. After diagnosis, the cause of nephrocalcinosis must be established to carry out a comprehensive approach to this entity. Although this is a common finding, it can be underdiagnosed due to the lack of knowledge of the different presentation patterns that exist. Many causes have been described related to this disease.A pictorial review about the most common features of cortical and medullary nephrocalcinosis both in ultrasound and CT is presented in the present work as well as a review of its main causes and graphics to easily recognize each pattern.

High-Value Recovery of the Iron via Solvent Extraction from Waste Nickel-Cadmium Battery Sulfuric Acid Leachate Using Saponified D2EHPA

A significant amount of iron from the waste nickel-cadmium (Ni-Cd) battery sulfuric acid leachate seriously hinders the separation and recovery of nickel and cadmium. Therefore, an efficient and economical way to remove iron from this leachate is desired. This paper demonstrated the efficient iron extraction from a simulated Ni-Cd battery sulfuric acid leachate with saponified Di (2-ethylhexyl) phosphoric acid (D2EHPA). The iron-loaded D2EHPA was then stripped with oxalic acid and the iron was recovered in the form of iron oxalate. This process realizes the efficient separation and high-value recovery of iron. The results showed that the saponification of the D2EHPA greatly promoted the extraction of iron from the Ni-Cd battery sulfuric acid leachate. Under suitable conditions, the iron’s single-stage extraction rate was more than 95%, and the iron’s single-stage stripping rate was more than 85%. Moreover, the iron’s extraction rate was more than 99% after two theoretical extraction stages, and the stripping rate was 95.6% after two theoretical stripping stages. The slope analysis determines that five molecules of D2EHPA were combined with one molecule of Fe3+ in the extraction process. The FT-IR analysis shows that the extraction mechanism of Fe3+ using the saponified D2EHPA is a cation exchange. These results can help guide the industrial separation and recovery of iron from the waste Ni-Cd battery sulfuric acid leachate.

Formation of calcium oxalates and carbonates due to water stress in “nopalitos”

The “nopalitos” (Opuntia ficus-indica L. Miller) is an essential source of calcium in the human diet; however, the bioavailability and viability of the mineral are limited by precipitating in the form of calcium oxalate (CaC2O4) when the plant is exposed to water stress. The objective of this study was to quantify calcium oxalates and carbonates in cactus subjected to water differentials of 10, 30 and 60% of available water (AW) through photomicrographic analysis. The micro mosaics are composed of sequential images of a 10x amplitude, taken in a petrographic microscope with different light sources, plane-polarized light (LPP), cross-polarized light (LPC), and light compensated (LPC). High spectral resolution mosaics were produced using geospatial operators (ArcGIS v.10.1 and ERDAS Imagine, 2014v®). The CaC2O4 and CaCO3 were identified by spectral signature or brightness degrees in RGB format images, quantifying the minerals and surface they occupy in the cladode. The quantification of minerals in situ in nopal cladodes at different water stresses showed significant differences (p<0.05) in the area occupied by oxalates at 10% water stress and calcium carbonates at 60% within the vegetal structures of nopal vegetables. Consequently, using high-resolution mosaics and spatial operators allows the identification and quantification of mineral biomarkers in plant tissues in situ. Therefore, using image overlay, the proposed method is an alternative to the in situ quantification of minerals in plant tissues.

Ferroptosis in calcium oxalate kidney stone formation and the possible regulatory mechanism of ANKRD1

The objective of this study was to explore the role of ferroptosis in the formation of calcium oxalate (CaOx) kidney stones and the regulatory mechanism of the ankyrin repeat domain 1 (ANKRD1) gene. The study found that the Nrf2/HO-1 and p53/SLC7A11 signaling pathways were activated in the kidney stone model group, and the expression of the ferroptosis marker proteins SLC7A11 and GPX4 was significantly reduced, while the expression of ACSL4 was significantly increased. The expression of the iron transport-related proteins CP and TF increased significantly, and Fe2+ accumulated in the cell. The expression of HMGB1 increased significantly. In addition, the level of intracellular oxidative stress was increased. The gene with the most significant difference caused by CaOx crystals in HK-2 cells was ANKRD1. Silencing or overexpression of ANKRD1 by lentiviral infection technology regulated the expression of the p53/SLC7A11 signaling pathway, which regulated the ferroptosis induced by CaOx crystals. In conclusion, CaOx crystals can mediate ferroptosis through the Nrf2/HO-1 and p53/SLC7A11 pathways, thereby weakening the resistance of HK-2 cells to oxidative stress and other unfavorable factors, enhancing cell damage, and increasing crystal adhesion and CaOx crystal deposition in the kidney. ANKRD1 participates in the formation and development of CaOx kidney stones by activating ferroptosis mediated by the p53/SLC7A11 pathway.

Oxalate Crystallization under the Action of Brown Rot Fungi

Brown rot fungi belong to the wood-rotting fungi, which produce oxalic acid and actively decompose wood. We first found oxalates formed under the action of brown rot fungi in natural conditions on stone (Rogoselga adit, Karelia, Russia), proposed a model for their formation, and confirmed the hypothesis that frequent occurrence of metal oxalates in mines and adits may be associated with the activity of these fungi. We synthesized under the action of four species of brown-rot fungi (Serpula himantioides, Serpula lacrymans, Coniophora puteana, Antrodia xantha) on different mineral substrates analogs of all known biofilm oxalate minerals and oxalates of such toxic heavy metals as Pb, Cu, Mn. In addition, we compared the features of oxalate formation under the action of brown rot fungi and soil fungus Aspergillus niger, an active oxalic acid producer, widely used in model experiments and recommended for application in biotechnologies. It is shown that in contrast to A.niger, the contribution of the metabolic activity of brown rot fungi to oxalate crystallization exceeds the contribution of the underlying minerals. The prospects for the use of brown rot fungi such as Serpula himantioides, Coniophora puteana, and Antrodia xantha in modern environmentally friendly biotechnologies are justified.

Morphological Regulation Mechanism of Tubular Ferrous Oxalate: Theoretical and Experimental Study

AbstractThe formation mechanism and morphology regulation mechanism of tubular ferrous oxalate were investigated by density functional theory. The calculation results showed that the pH value of the reaction solution changed from slightly alkaline to acidic was an important condition for the formation of tubular ferrous oxalate. The size and dispersion of ferrous oxalate can be controlled by introducing Na+ and ethylene glycol (EG) into the reaction system. Guided by theoretical calculations, using sodium oxalate as material to guarantee the initial solution to be slightly basic, while also introducing Na+. Regular tubular ferrous oxalate was successfully obtained by using different ratios of EG and H2O as reaction solution and adjusting pH values at different stages, verified the rationality of the theoretical calculation results. The tubular ferric oxide was obtained by thermal decomposition using tubular ferrous oxalate as the precursor, and the electrochemical performance test results showed that this material is a potential electrode material for supercapacitors.

Stone Formation Features in the Kidney of Residents in the South Region of Kyrgyzstan

Kidney stone disease (KSD), otherwise urolithiasis, is one of the most common and frequent diseases and occurs most often in patients of working age. With “urolithiasis” there is a metabolic disorder characterized by the presence of stones in the kidneys and urinary tract. Formation of kidney stones in residents of southern region in Kyrgyzstan has not been studied. Research objectives: determination of stone formation features in the kidney of patients in the southern region of Kyrgyzstan. Research materials and methods: a literary review of urolithiasis (KSD) of the kidneys and identification of stone formation features. Research results: kidney stone formation is a complex physical and chemical process, accompanied by growth, aggregation and retention of urinary stone in parts of tubular cells. Conclusions: formation of calcium oxalate and uric acid stones is associated with various metabolic processes in the body. Urinary calculi are formed as a result of a series of sequence of stages.

Retrospective analysis of 131 feline uroliths from the Republic of Ireland and Northern Ireland (2010-2020)

BackgroundThe proportions of different urolith types have not been investigated in cats from the Republic of Ireland (ROI) and Northern Ireland (NI) previously. The objective of this study was to investigate the proportions of different feline urolith types submitted to Minnesota Urolith Center from the ROI and NI from 2010 to 2020. An additional aim of this study was to identify potential risk factors associated with each urolith type in cats in this geographic area.ResultsOne hundred and thirty-one uroliths were submitted for the studied period with 44.3% being struvite, 43.5% calcium oxalate and 7.6% compound. Only 11 uroliths were submitted in the first 4 years. The number of submissions increased after 2015, peaking in 2019 with 25 submissions. Due to low numbers no conclusions could be made about changes in incidence of urolith types over time. Cats ≤7 years of age were significantly more likely to be diagnosed with struvite uroliths (OR, 2.87 [1.37-6.06]; p = 0.007) while cats ≥7 years of age with calcium oxalate uroliths (OR, 2.67, [1.29-5.37], p = 0.004).ConclusionsThis is the first epidemiologic study of urolithiasis from cats in the ROI and NI. The most prevalent types of uroliths in our study population were struvite and calcium oxalate. Due to the low number of urolith submissions, changes in the incidence of different uroliths could not be accurately determined. Increasing age was associated with calcium oxalate formation while younger cats were more commonly diagnosed with struvite urolithiasis which can be medically dissolved. Therefore, urolith dissolution is more likely to be successful in young cats than older cats.

Novel theoretical insight on CO2 electroreduction mechanism induced by aromatic ester-functionalized ionic liquids: A bulk-phase reaction pathway

CO2 electroreduction reaction (CO2ER) to high valued products in ionic liquid (IL) systems is a promising way for CO2 utilization, and understanding the mechanism on CO2ER will be helpful to design new electrolytes. In this study, the mechanism of CO2 to oxalate using the aromatic ester-functionalized IL ([N2222][4-MF-PhO]) was systematically investigated by the Density Functional Theory (DFT) calculations. A new reaction pathway named bulk-phase pathway was proposed in which the contribution of the electrolyte to CO2 reactions is more important than the electrode surface as shown in most reports. Our simulation results indicated that CO2 does not obtain electrons from the electrode directly, while the anion of the IL, [4-MF-PhO]−, acts as a catalyst and electron transporter in the new pathway. The reason is that the bulk-phase pathway has lower free energy barriers and higher selectivity for oxalate compared with the formation of oxalate on the electrode surface. The new insight was proved by the experimental work in our previous studies. Inspired by the bulk-phase pathway, the interactions of CO2 with the reduced esters, ketones and nitriles containing unsaturated bonds were further studied. It was found that the lower the Gibbs free energy barrier for them binding to CO2, the more charge is transferred to CO2. The new theoretical insight proposed in this work will be helpful for the design of IL electrolytes in CO2ER.

Development and evaluation of 89Zr-trastuzumab for clinical applications.

Due to the suitable physical characteristics of 89Zr as a PET radionuclide and affinity of Trastuzumab monoclonal antibody against HER2, [89Zr]Zr-Trastuzumab was prepared and went through preclinical evaluations for ultimate human applications. 89Zr was produced by using 89Y(p,n)89Zr reaction at a 30 MeV cyclotron (radionuclide purity>99.9%, specific activity of 17 GBq/µg). p-SCN-Bn-Deferoxamine (DFO); was conjugated to trastuzumab, followed by labeling with 89Zr in oxalate form at optimized condition. Cell binding, internalization and, radioimmuno-activity assays were studied using HER2+ BT474 and HER2- CHO cell lines. Finally, the biodistribution of the radioimmunoconjugate was assessed in normal and HER2+ BT474 tumor-bearing mice using tissue counting and imaging at different intervals after injection. Also, a woman with HER2-positive metastatic breast cancer under treatment with Herceptin underwent both [89Zr]Zr-Trastuzumab and, [18F]FDG PET/CTs. 89Zr was produced with high radionuclidic and radiochemical purities (>99%) and [89Zr]Zr-DFO-Trastuzumab was prepared with radiochemical purity of >98% and specific activity of 9.85 GBq/µmol. The radioimmunoconjugate was stable both in PBS buffer and in human serum for at least 48 h. The radioimmunoactivity assay demonstrated about 70% of [89Zr]Zr-DFO-Trastuzumab is bound to the BT474 cells at the number of 250×106 cells. Cell binding studies showed that about 28% of radioimmunoconjugate is attached to BT474 cells after 90 min. Internalization studies showed that 50% of [89Zr]Zr-Trastuzumab is internalized to BT474 cells only in 6 h. The biodistribution study of the labeled compound in normal mice demonstrated the same pattern of the monoclonal antibodies which is entirely different from the biodistribution of free 89Zr. Biodistribution and imaging studies in tumor-bearing mice showed the significant uptake values of [89Zr]Zr-Trastuzumab in tumor sites. [89Zr]Zr-Trastuzumab PET/CT revealed metastatic lesions documented previously with [18F]FDG PET/CT scan in a woman with breast cancer who was under treatment with Herceptin. Although the [18F]FDG PET/CT scan had better quality images, the valuable and unique advantage of [89Zr]Zr-Trastuzumab PET/CT is delineating HER2+ metastasis, which is essential in diagnosis and HER2-based treatments. The prepared [89Zr]Zr-Trastuzumab has a high potential radio-pharmaceutical for immune-PET imaging of the patients with HER2+ tumors.

Synergistic inhibition of calcium oxalate crystal formation and synergistic protection of HK-2 cells from crystal damage by sulfated Laminarin polysaccharide and potassium citrate.

Objective: The first objective is to study the synergistic inhibition of calcium oxalate (CaOx) formation by Laminarin polysaccharides (DLP and SDLP, before and after sulfation) and potassium citrate (K3cit) and determine the synergistic protection of renal epithelial cells (HK-2 cells) caused by CaOx crystal damage. The second objective is to explore new ways to prevent and treat kidney stones. Methods: The CaOx crystals regulated by five additives (K3cit group, DLP group, SDLP group, DLP-K3cit synergistic group and SDLP-K3cit synergistic group) were characterized by FT-IR, XRD, SEM, zeta potential, ICP, and TGA. The protective effect of each additive group on HK-2 cells damaged by nano-calcium oxalate monohydrate (nano-COM) was compared by detecting cell viability, the cell reactive oxygen species level, the cell survival rate, and mitochondrial membrane potential. Results: When DLP or SDLP acted synergically with K3cit, the synergistic group induced the same amount of COD at a lower concentration or more COD formation at the same concentration, highlighting the synergistic enhancement effect of 1 + 1 > 2. At 0.3 g L-1, the COD contents induced by DLP, SDLP, K3cit, DLP-K3cit, and SDLP-K3cit synergistic groups were 20.3%, 75.8%, 75.4%, 87.3%, and 100%, respectively. The synergistic group increased the concentration of soluble Ca2+ ions in the supernatant, increased the absolute value of the zeta potential on the surface of CaOx crystals, and inhibited the aggregation among the crystals. TGA and DTG analyses established the adsorption of polysaccharides in the crystals. Cell experiments showed the ability of the synergistic group to significantly inhibit the damage of nano-COM crystals on HK-2 cells, reduce the level of reactive oxygen species and mortality, and improve cell viability and the mitochondrial membrane potential. Conclusions: The synergistic group can more effectively induce COD formation and cell protection than the standalone polysaccharide group or K3cit group. The synergistic groups, especially SDLP-K3cit, may be a potential drug for inhibiting the formation of CaOx kidney stones.

Multiplex gene editing reduces oxalate production in primary hyperoxaluria type 1.

Targeting key enzymes that generate oxalate precursors or substrates is an alternative strategy to eliminate primary hyperoxaluria type I (PH1), the most common and life-threatening type of primary hyperoxaluria. The compact Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) from the Prevotella and Francisella 1 (Cpf1) protein simplifies multiplex gene editing and allows for all-in-one adeno-associated virus (AAV) delivery. We hypothesized that the multiplex capabilities of the Cpf1 system could help minimize oxalate formation in PH1 by simultaneously targeting the hepatic hydroxyacid oxidase 1 ( Hao1) and lactate dehydrogenase A ( Ldha) genes. Study cohorts included treated PH1 rats ( Agxt Q84X rats injected with AAV-AsCpf1 at 7 days of age), phosphate-buffered saline (PBS)-injected PH1 rats, untreated PH1 rats, and age-matched wild-type (WT) rats. The most efficient and specific CRISPR RNA (crRNA) pairs targeting the rat Hao1 and Ldha genes were initially screened ex vivo. In vivo experiments demonstrated efficient genome editing of the Hao1 and Ldha genes, primarily resulting in small deletions. This resulted in decreased transcription and translational expression of Hao1 and Ldha. Treatment significantly reduced urine oxalate levels, reduced kidney damage, and alleviated nephrocalcinosis in rats with PH1. No liver toxicity, ex-liver genome editing, or obvious off-target effects were detected. We demonstrated the AAV-AsCpf1 system can target multiple genes and rescue the pathogenic phenotype in PH1, serving as a proof-of-concept for the development of multiplex genome editing-based gene therapy.

A molecular understanding of citrate adsorption on calcium oxalate polyhydrates.

Calcium oxalate precipitation is a common pathological calcification in the human body, whereby crystallite morphology is influenced by the chelating properties of biological ions such as citrate. It has been suggested that citrate could steer oxalate formation towards its dihydrated form and away from the monohydrated form, which was identified as a major cause for disease. To assess the influence of the citrate ion on the resulting calcium oxalate, surface energies were calculated at the dispersion-corrected density functional level of theory for both monohydrated and dihydrated calcium oxalate. Different adsorption geometries were considered by varying the attacking angle of citrate as well as by considering the citrate ion on top of an adsorbed water layer or penetrating the water layer. The obtained results were compared to ab initio molecular dynamics simulations and experimental scanning electron microscope images. A strong preference for citrate adsorption on calcium oxalate dihydrate was observed, suggesting medical applications for the treatment of such pathological calcifications.

The effects of salt-loss soda residue and oxalate acid on property and structure of fly ash-based geopolymer

When industrial solid waste soda residue (SR) is subjected to water erosion, certain soluble salts are lost, which influences the reuse of SR in construction materials. This research studies the possibility of using salt-loss soda residue (SLSR) in fly ash (FA)-based geopolymers activated by sodium hydroxide solution (NS). To achieve a wider application, the SR and SLSR were proposed with an oxalic acid (OA) treatment. Fluidity, electrical conductivity, and densitywere assessed to examine the effects of SLSR and OA on fresh and hardened characteristics. In addition, flexural and compressive strengths, as well as drying shrinkages, were tested to investigate the role of SLSR and OA. Furthermore, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FTIR) tests were carried out to evaluate the mineralogy, morphology, and products. Thermal stability was further evaluated using Thermo-Gravimetric and Differential Thermal Synchronous Thermal Analysis Spectrometer (TG-DSC) tests. The results show that SLSR and OA can be used to synthesize FA-based geopolymers at room temperature. When proper OA is introduced, SLSR contributes to higher compressive strength, improved drying shrinkage resistance, and increased thermal stability of FA-based geopolymers than SR due to the loss of soluble salts and the formation of calcium oxalate in the matrix. Furthermore, it is revealed that the structure of hardened paste (V4) prepared with SLSR, FA, and OA is composed of chemical CSH and (N, C)-ASH gels together with physically filled particles (such as calcite, calcium oxalate, sodium oxalate, and unreacted glass microsphere). The research findings give guidance for promoting the preparation of SLSR products and the utilization of organic calcium sources in geopolymer.

Effect of oxalic acid pretreatment on the mechanical properties and microstructure of phosphogypsum

In China, the amount of phosphogypsum (PG) accumulated has been increasing rapidly with the development of the phosphate fertilizer industry. PG exists mainly in the form of dihydrate gypsum, which can replace natural gypsum to produce hemihydrate gypsum and is used in the building materials industry. However, it contains impurities, such as phosphate, fluoride, sulfate, and natural radioactive elements, which limit its application and seriously pollute the surrounding environment. To promote the application of PG, it is crucial to understand how pretreatment affects the properties of hemihydrate phosphogypsum (HPG). In this research, the mechanical properties and microstructure of HPG after pretreatment was investigated for improving the reuse of PG as a promising resource. The harmful phosphorus impurity in PG was efficiently removed with different concentrations of by H2C2O4. Then the hydration process and the hardening characteristics of HPG were studied in detail. The findings indicate that H2C2O4 alters the particle characteristics of HPG and has an impact on hemihydrate gypsum dissolution and dihydrate gypsum precipitation. According to studies, small amounts of H2C2O4 can remove impurities, promoting hydration and enhancing strength by opening the closed orifice of HPG, which would promote the dissolution of HPG and alter the morphology of gypsum from a tiny crystal to a thickened columnar structure. However, the addition of excessive H2C2O4 impacts the compression strength of HPG plaster and reduces the rehydration of HPG due to the formation of calcium oxalate on the gypsum crystal surface. These new findings may give insight into how H2C2O4 affects the performance of HPG. Therefore, to ensure the efficient utilization of PG, quality stabilization and improvement are crucial.

Efficacy of chlorogenic acid against ethylene glycol-induced renal stone model: The role of NFKB-RUNX2-AP1-OSTERIX signaling pathway

Background and objectiveRenal tissue injuries by free radicals are an essential reason in pathogenesis of urinary tract stones. Ethylene glycol is one of the toxic agents which can causes to the increases in biosynthesis of reactive oxygen species and oxidative stress condition. Natural antioxidants have been reported to protective efficacy against renal stones formation. Accordingly, the aim of the current experiment was to identify the renal protective effect of chlorogenic acid as a well-prominent antioxidant on ethylene glycol-induced renal stone model targeting the NFKB-RUNX2-AP1-OSTERIX signaling pathway. Materials and methodsRenal stones model were established by ethylene glycol (Percent: 0.75) within the daily drinking water for rats. Treatment groups received cystone (750 mg/kg) and chlorogenic acid (100, 200, and 400 mg/kg, day: 15th to 28th, gavage). After 4 weeks, the renal function parameters (calcium, uric acid, creatinine, total protein, oxalate, and citrate) in plasma, urine, and renal tissue were measured. Moreover, oxidative stress factors and gene expression of NFKB, RUNX2, AP1, and OSTERIX were also evaluated. ResultsThe results showed improved renal function in chlorogenic acid-treated groups. The total proteins and creatinine excretion were decreased. Also the gene expression of oxidative stress pathway (NFKB-RUNX2-AP1-OSTERIX) were decreased which caused to increases of antioxidant enzymes. Conclusionsthe antioxidant activity increases by chlorogenic acid treatment may have a critical role in prevention of calcium oxalate formation via inhibition of the NFKB-RUNX2-AP1-OSTERIX signaling pathway.