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A two-dimensional (2D) coordination polymer [Co(ox)(bpy)] 1 (ox = oxalate, bpy = 4,4'-bipyridine) was prepared by hydrothermal synthesis using CoCl2⋅5H2O, oxalic acid, bpy as raw material. Compound 1 is a 2D structure extended by ox and bpy, and it has excellent visible photocatalytic performance. The photocatalytic efficiency of compound 1 could reach up to 98.13% with pH = 10 when two drops of H2O2 were added to methylene blue. The photocatalytic degradation results could be described by the first-order kinetic. Besides, after five cycles, the degradation efficiency decreased only 4.11% (without H2O2) and 5.22% (with H2O2). Meanwhile, the solid fluorescence and UV-Visible diffuse reflection of compound 1 were also studied. What's more, the visible light photo- catalytic mechanism of compound 1 was analyzed more clearly by free radical trapping experiment and Mott-Schottky curve. [ABSTRACT FROM AUTHOR]

Calcium (Ca) plays a vital role as a macronutrient in the growth and development of plants. In order of decreasing solubility, Ca can be found in vegetal tissues as soluble Ca (Fraction I), bound Ca (mainly pectates, Fraction II), inorganic insoluble Ca (mainly phosphates and carbonates, Fraction III) and organic insoluble Ca or oxalate (Fraction IV). To explore the impact of Ca fertilizer application on plant growth and its allocation among different fractions, young citrus trees were fed over a complete vegetative cycle with a 44Ca labeled fertilizer (T1-Ca), while control plants (T2) received no Ca fertilizer. The results showed that plants receiving Ca exhibited significantly greater biomass. 44Ca derived from the fertilizer was localized mainly in sink organs (new flush leaves–twigs and fibrous roots). The primary fraction responsible for total Ca partitioning was Fraction II, followed by Fraction III or IV. Citrus plants, commonly found in calcareous soils, demonstrated improved growth with calcium treatments, indicating a positive link between calcium supplementation and enhanced development. The calcium supplied through the fertilizer (44Ca) was predominantly concentrated in sink organs (mainly in Ca-pectate fraction), including new flush leaves and twigs above ground, as well as fibrous roots below ground. [ABSTRACT FROM AUTHOR]

Consumers perceive flavor as a critically important attribute of vegetable crops. Gas chromatography-mass spectrometry (GC-MS), spectrophotometry, and refractometry of tissue samples collected during multiple years from table beet (Beta vulgaris) at various stages of maturity were performed to characterize the endogenous production of geosmin, oxalic acid, and total dissolved solids within the root. The geosmin concentration was primarily influenced by the cultivar and peaked early during the growing season, with root concentrations at 6 weeks after planting that were 312% higher, on average, than those found in harvest stage roots at 15 weeks after planting. The highest average concentration of geosmin in harvest stage roots was detected in tissue from the cultivar Bull’s Blood (16.08 μg⋅kg−1). The oxalic acid concentration showed a strong cultivar influence and statistically significant variability across the growing season. Hybrid beet cultivar Boro had the lowest soluble oxalic acid concentration (95.73 mg⋅100 g−1 fresh tissue) at all locations and during all years. The oxalic acid concentration peaked 12 weeks after planting, and it was lower at the postharvest sampling date 18 weeks after planting. Total dissolved solids (TDS) concentrations were strongly influenced by year and growing environment and displayed crossover interactions for environment × week. TDS measurements had a moderate negative correlation with root mass. ‘Chioggia Guardsmark’ consistently had the highest TDS during all years and at all locations at 12.01 °Brix. The TDS varied significantly according to time, and diurnal sampling revealed fluctuations as large as 4 °Brix over the course of a 12-hour period. The TDS concentrations increased throughout the growing season, although the rate at which they increased changed according to plant age. The results from this study suggest that interactions between cultivar, time, and environment are important determinants of oxalic acid and TDS concentrations, but they have less influence on geosmin. This information may influence the methods that plant breeders use to collect phenotypic data of important flavor compounds in beets.

Abstract Oxalate nephropathy, due to secondary hyperoxaluria has widely been described in gastrointestinal diseases. However, reports of oxalate nephropathy in newly diagnosed celiac disease are rare. A 72-year-old Caucasian male presented to the hospital with abdominal discomfort and acute renal insufficiency with a creatinine of 290 µmol/L. The clinical course, laboratory results and urinalysis were suspect for tubular injury. Renal biopsy showed calcium oxalate depositions. Elevated plasma and urine oxalate levels established the diagnosis oxalate nephropathy. The abdominal complaints with steatorrhea and positive anti-tissue transglutaminase antibodies were diagnosed as celiac disease, which was confirmed after duodenal biopsies. Treatment with prednisone, and gluten-free, low oxalate and normal calcium diet, lowered the plasma oxalate levels and improved his renal function. Decreased absorption of free fatty acids can lead to increased free oxalate in the colon due to the binding of free fatty acids to calcium, preventing the formation of the less absorbable calcium oxalate in the colon. Oxalate dispositions in the kidney can lead to acute tubular injury and chronic renal insufficiency. Celiac disease is therefore one of the intestinal diseases that can lead to hyperoxaluria and oxalate nephropathy.

Abstract Background Coffee bean weevil (Araecerus fasciculatus DeGeer) (Coleoptera: Anthribidae) infestation is a major challenge affecting processed, dried, and stored foods globally. However, the growth performance of this insect pest in processed and stored cassava, plantain, yam, and cocoyam is poorly understood. Resolving this will guide future biotechnological efforts on these food products. In the study, the susceptibility rate of the processed and stored product of cassava, yam, cocoyam, and plantain to the growth performance of the coffee bean weevil at laboratory conditions (20 ± 5 °C and 70 ± 5% R.H.) was investigated. The anti-nutritional (phytate, alkaloids, saponin, tannin, and oxalate) contents of this stored food were used to characterize the survival rate of A. fasciculatus. The study was carried out for 6 months between December 2012 and May 2013. Results Results show that the adult longevity, growth, and feeding of the adult A. fasciculatus decrease in order from Cassava, Plantain, Yam to Cocoyam. Cocoyam has the highest tannin, alkaloid, and phytate values, which are possible factors that inhibited the growth of the larvae, pupae, and adults’ A. fasciculatus. The highest weight loss occurred in cassava followed by plantain. The anti-nutritional factors determine the hatchability of the A. fasciculatus eggs and throughout its development stages. This study revealed that processed and stored products (e.g., cocoyam) with high anti-nutritional factors can survive A. fasciculatus under prolonged storage. Conclusions From this study, it is observed that high anti-nutritional compounds in the stored food products inhibit the growth of Araecerus fasciculatus, especially in cocoyam. The result is important in food security and management in developing countries where food insecurity has become a major challenge.

The sensing of oxalate within urine has been recognised as one of the most important determinations in the investigation of patients with hyperoxaluria. However, current approaches have reported expensive, time consuming, occasionally poor selectivity and are subject to large inaccuracies if great care is not exercised in the handling and measurement of samples. One approach is the use of electroanalytical sensors, which present rapid but highly selective and sensitive outputs, are economical and miniature providing portable sensing platforms to support on-site analysis. In this minireview, recent advances in the electroanalytical sensing of oxalate are presented, overviewing recent electrode configurations and real sample analysis; comparisons to other analytical methods are presented. Finally, the conclusions and future perspective of this field are described in brief.

We present a photon‐ and metal‐free approach for the radical fluorination of aliphatic oxalate‐activated alcohols. The method relies on the spontaneous generation of the N‐(chloromethyl)triethylenediamine radical dication, a potent single electron oxidant, from Selectfluor and 4‐(dimethylamino)pyridine. The protocol is easily scalable and provides the desired fluorinated products within only a few minutes reaction time. [ABSTRACT FROM AUTHOR]

Nickel-iron non-precious catalysts for oxygen evolution reaction (OER) have attracted much attention in recent years due to their low-cost and excellent catalytic performance. In this work, a green synthesis method of adding carbon nanotubes (CNTs) into oxalate-based Ni–Fe metal organic framework (Ni–Fe MOF) obtained a highly efficient OER catalyst, Ni–Fe MOF/CNT. By tuning the amount of CNTs added, it was found that 30% (mass fraction) addition of CNTs showed the best OER performance, with an over-potential of only 240 mV at the current density of 10 mA cm−2 and a small Tafel slope of 37.2 mV dec−1 in 1 M KOH solution. Further study showed that the addition of CNTs did not obviously change the Ni–Fe MOF phase. The excellent catalytic activity should be attributed to the formed Ni–Fe hydroxides during the OER reaction in alkaline solution. The result revealed that CNTs can effectively improve the conductivity of oxalate-based Ni–Fe MOF, and further enhance the OER catalytic activity. This work provides good references for the synthesis of highly efficient non-precious OER catalysts using simple green methods. A green method of preparing non-precious OER catalysts by adding carbon nanotubes (CNTs) into oxalate-based Ni–Fe MOF was reported. The material of Ni–Fe MOF/CNT showed an over-potential of only 240 mV at 10 mA cm−2 and a small Tafel slope of 37.2 mV dec−1 in 1 M KOH solution. The values were comparable to or even better than other similar non-noble Ni–Fe OER catalysts, and also obviously superior to the commercial catalyst of IrO 2. [Display omitted] • New Ni–Fe MOF based OER catalyst was prepared. • High OER performance, with an overpotential of only 240 mV in 1 M KOH. • The catalyst has very stable and reliable catalytic performance. • Green synthesis, low energy consumption and environmentally friendly. [ABSTRACT FROM AUTHOR]

Globally prevalent renal stone diseases are extremely painful and affect people all over the world. Given the importance of the role of elements in their formation and the fact that the growth and genesis of renal stones are imprinted in their morphology, the etiology of lithiasis could be studied with relevant analytical tools. The prime objective of this investigation is to describe the compositional structure and morphology of nineteen surgically removed renal stones. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy is used to obtain the chemical and structural compositions of the stones. Thermal gravimetric and differential scanning calorimetry analyses were also performed to understand their thermal behaviors. Calcium oxalate monohydrate, along with some traces of calcium phosphate, uric acid, and sodium urate, represents the main mineralogical phase of the renal stones used in the present study. A scanning electron microscopic study showed that calcium oxalate monohydrate crystals had a sphere-like, clumping-like morphology with irregularities in their sizes and orientations and were more tightly packed and regularly ordered in comparison to the uric acid crystals. Elemental imaging and mapping of the main and trace elements within the renal stones were also obtained, which reveals the heterogeneous nature of stones. [ABSTRACT FROM AUTHOR]

This study examined the profile of patients and the impact of diet on the risk of brushite stone formation under controlled, standardized conditions. Sixty-five patients with brushite nephrolithiasis were enrolled in the study. Metabolic, dietary, and 24 h urinary parameters were collected under the habitual, self-selected diet of the patients and the balanced mixed, standardized diet. The [13C2]oxalate absorption, ammonium chloride, and calcium loading tests were conducted. All patients had at least one abnormality on the usual diet, with hypercalciuria (84.6%), increased urine pH (61.5%), and hyperphosphaturia (43.1%) being the most common. Absorptive hypercalciuria was present in 32.1% and hyperabsorption of oxalate in 41.2%, while distal renal tubular acidosis (dRTA) was noted in 50% of brushite stone formers. The relative supersaturation of brushite did not differ between patients with and without dRTA. Among all recent brushite-containing calculi, 61.5% were mixed with calcium oxalate and/or carbonate apatite. The relative supersaturation of brushite, apatite, and calcium oxalate decreased significantly under the balanced diet, mainly due to the significant decline in urinary calcium, phosphate, and oxalate excretion. Dietary intervention was shown to be effective and should be an integral part of the treatment of brushite stone disease. Further research on the role of dRTA in brushite stone formation is needed. [ABSTRACT FROM AUTHOR]

Kidney stone is a highly recurrent disease in the urinary tract system. Most kidney stones are calcium stones, usually consisting of either calcium oxalate or calcium phosphate. Supersaturation of soluble calcium, oxalate, phosphate, and citrate in the urine is the basis for calcium stone formation. Genetics, diet, low physical activity, and individual habits contribute to the formation of kidney stones. In this review, the associations of the risk of kidney stones with oxalate consumption and some individual habits, such as smoking, alcohol drinking, and opium consumption, are summarized. [ABSTRACT FROM AUTHOR]

Consumers perceive flavor as a critically important attribute of vegetable crops. Gas chromatography-mass spectrometry (GC-MS), spectrophotometry, and refractometry of tissue samples collected during multiple years from table beet (Beta vulgaris) at various stages of maturity were performed to characterize the endogenous production of geosmin, oxalic acid, and total dissolved solids within the root. The geosmin concentration was primarily influenced by the cultivar and peaked early during the growing season, with root concentrations at 6 weeks after planting that were 312% higher, on average, than those found in harvest stage roots at 15 weeks after planting. The highest average concentration of geosmin in harvest stage roots was detected in tissue from the cultivar Bull's Blood (16.08 µg·kg-1). The oxalic acid concentration showed a strong cultivar influence and statistically significant variability across the growing season. Hybrid beet cultivar Boro had the lowest soluble oxalic acid concentration (95.73 mg·100 g-1 fresh tissue) at all locations and during all years. The oxalic acid concentration peaked 12 weeks after planting, and it was lower at the postharvest sampling date 18 weeks after planting. Total dissolved solids (TDS) concentrations were strongly influenced by year and growing environment and displayed crossover interactions for environment × week. TDS measurements had a moderate negative correlation with root mass. 'Chioggia Guardsmark' consistently had the highest TDS during all years and at all locations at 12.01 °Brix. The TDS varied significantly according to time, and diurnal sampling revealed fluctuations as large as 4 °Brix over the course of a 12-hour period. The TDS concentrations increased throughout the growing season, although the rate at which they increased changed according to plant age. The results from this study suggest that interactions between cultivar, time, and environment are important determinants of oxalic acid and TDS concentrations, but they have less influence on geosmin. This information may influence the methods that plant breeders use to collect phenotypic data of important flavor compounds in beets. [ABSTRACT FROM AUTHOR]

Exploring nonlinear optical crystals with large birefringence in the short‐wavelength ultraviolet (SWUV) regions (≤300 nm) is a valuable pursuit. Herein, KHC2O4·B(OH)3, which is composed of infinite [HC2O4]− and [B(OH)3] chains, was successfully grown via the slow evaporation method. The [HC2O4]− and [B(OH)3] chains endow KHC2O4·B(OH)3 with the largest birefringence (0.164@1064 nm) of all B(OH)3‐containing compounds that have been reported in the SWUV regions. Moreover, it possesses a moderate second‐harmonic generation response (0.3 × KH2PO4) and a short UV cutoff edge of 254 nm. The electron localization function diagram indicates the large birefringence originates from the HC2O4 and B(OH)3 groups. This work provides a new method to investigate crystals with large birefringence in the B(OH)3‐based oxalate system. [ABSTRACT FROM AUTHOR]

Oxalate is an antinutrient present in a wide range of foods, with plant products, especially green leafy vegetables, being the main sources of dietary oxalates. This compound has been largely associated with hyperoxaluria, kidney stone formation, and, in more severe cases, systematic oxalosis. Due to its impact on human health, it is extremely important to control the amount of oxalate present in foods, particularly for patients with kidney stone issues. In this review, a summary and discussion of the current knowledge on oxalate analysis, its extraction conditions, specific features of analytical methods, reported occurrence in foods, and its health implications are presented. In addition, a brief conclusion and further perspectives on whether high-oxalate foods are truly problematic and can be seen as health threats are shown. [ABSTRACT FROM AUTHOR]

Primary hyperoxalurias (PHs) are inherited metabolic disorders marked by enzymatic cascade disruption, leading to excessive oxalate production that is subsequently excreted in the urine. Calcium oxalate deposition in the renal tubules and interstitium triggers renal injury, precipitating systemic oxalate build-up and subsequent secondary organ impairment. Recent explorations of novel therapeutic strategies have challenged and necessitated the reassessment of established management frameworks. The execution of diverse clinical trials across various medication classes has provided new insights and knowledge. With the evolution of PH treatments reaching a new milestone, prompt and accurate diagnosis is increasingly critical. Developing early, effective management and treatment plans is essential to improve the long-term quality of life for PH patients.

The iron‐based polyanionic fluoro‐oxalate material, KFe(C2O4)F (KFCF), has been synthesized by hydrothermal methods. This compound shows promising reversible lithium and sodium insertion properties as a cathode material. The material delivered a first‐cycle discharge capacity of 120 mAh g−1 at ∼3.3 V (Li+/Li) and 97.4 mAh g−1 at ∼3.0 V (Na+/Na) in LIB and NIB, respectively. Stable cycling performance was observed in both cases. The involvement of reversible Fe2+/Fe3+ redox was confirmed by ex‐situ Mössbauer spectroscopy supported by first‐principles calculations. This study reveals promising performance from a mixed oxalate‐fluoride based polyanionic material thereby opening up further possibilities for materials discovery in the design of new electrode materials. [ABSTRACT FROM AUTHOR]

Yellow patina formed on the stone surfaces of historical buildings, monuments, and archaeological structures due to weathering is considered a value of the building in the conservation of cultural heritage studies. Although yellow patina layers can be easily distinguished on white marble surfaces, it is not possible to distinguish them on the yellow travertine surfaces with the naked eye. It should be taken into account in yellow travertines as well as marble surfaces before conservation treatments of the stone. In this study, mineralogical and chemical compositions and the thicknesses of yellow patina layers formed on yellow travertine and marble surfaces in Aizanoi, Aphrodisias, and Hierapolis archaeological sites in Turkey were analyzed in order to constitute a conservation approach in the archaeological sites. In this respect, XRD, FT-IR, SEM-EDX, and LIBS were used in the determination of compositions and thicknesses of yellow patina. Although LIBS analysis is a more convenient method to investigate patina layers on stone surfaces, this technique is not as well known as the others. Yellow patina layers contained calcium oxalate in the form of whewellite (CaC2O4.H2O). Their thicknesses were between 15 and 100 μm and should be protective against weathering on travertine and marble surfaces. LIBS analysis seems to be the most convenient micro-destructive method to estimate the thickness of the yellow patina layers on the marble and yellow travertine surfaces. The determination of the thickness of the yellow patina is critical to keep irreversible cleaning interventions, especially for the yellow travertines due to their similar colors. Yellow patina is mainly composed of calcium oxalate with clay minerals and organic compounds. [ABSTRACT FROM AUTHOR]

Cerium is the most sought-after rare earth element (REE) for application in high-tech electronic devices and versatile nanomaterials. In this research, biomass-free spent culture media of Aspergillus niger and Neurospora crassa containing precipitant ligands (oxalate, carbonate) were investigated for their potential application in biorecovery of Ce from solution. Precipitation occurred after Ce3+ was mixed with biomass-free spent culture media and >99% Ce was recovered from media of both organisms. SEM showed that biogenic crystals with distinctive morphologies were formed in the biomass-free spent medium of A. niger. Irregularly-shaped nanoparticles with varying sizes ranging from 0.5 to 2 μm and amorphous biominerals were formed after mixing the carbonate-laden N. crassa supernatant, resulting from ureolysis of supplied urea, with Ce3+. Both biominerals contained Ce as the sole metal, and X-ray diffraction (XRD) and thermogravimetric analyses identified the biominerals resulting from the biomass-free A. niger and N. crassa spent media as cerium oxalate decahydrate [Ce 2 (C 2 O 4) 3 ·10H 2 O] and cerium carbonate [Ce 2 (CO 3) 3 ·8H 2 O], respectively. Thermal decomposition experiments showed that the biogenic Ce oxalates and carbonates could be subsequently transformed into ceria (CeO 2). FTIR confirmed that both amorphous and nanoscale Ce carbonates contained carbonate (CO 3 2−) groups. FTIR-multivariate analysis could classify the biominerals into three groups according to different Ce concentrations and showed that Ce carbonate biominerals of higher purity were produced when precipitated at higher Ce3+ concentrations. This work provides new understanding of fungal biotransformations of soluble REE species and their biorecovery using biomass-free fungal culture systems and indicates the potential of using recovered REE as precursors for the biosynthesis of novel nanomaterials. [Display omitted] • Biomass-free spent fungal media achieved >99% biorecovery of cerium from solution. • Carbonate-laden N. crassa media precipitated Ce carbonate [Ce 2 (CO 3) 3 ·8H 2 O]. • Oxalate-laden A. niger media precipitated Ce oxalate decahydrate [Ce 2 (C 2 O 4) 3 ·10H 2 O]. • Biogenic Ce oxalates and carbonates were thermally transformed into ceria (CeO 2). • Demonstration of REE biorecovery by biomass-free fungal culture systems. [ABSTRACT FROM AUTHOR]

Oxalate nephropathy, due to secondary hyperoxaluria has widely been described in gastrointestinal diseases. However, reports of oxalate nephropathy in newly diagnosed celiac disease are rare. A 72-year-old Caucasian male presented to the hospital with abdominal discomfort and acute renal insufficiency with a creatinine of 290 µmol/L. The clinical course, laboratory results and urinalysis were suspect for tubular injury. Renal biopsy showed calcium oxalate depositions. Elevated plasma and urine oxalate levels established the diagnosis oxalate nephropathy. The abdominal complaints with steatorrhea and positive anti-tissue transglutaminase antibodies were diagnosed as celiac disease, which was confirmed after duodenal biopsies. Treatment with prednisone, and gluten-free, low oxalate and normal calcium diet, lowered the plasma oxalate levels and improved his renal function. Decreased absorption of free fatty acids can lead to increased free oxalate in the colon due to the binding of free fatty acids to calcium, preventing the formation of the less absorbable calcium oxalate in the colon. Oxalate dispositions in the kidney can lead to acute tubular injury and chronic renal insufficiency. Celiac disease is therefore one of the intestinal diseases that can lead to hyperoxaluria and oxalate nephropathy. [ABSTRACT FROM AUTHOR]

Purpose: Urolithiasis is a known risk factor for chronic kidney disease (CKD). However, how CKD might affect the risk of incidence of urolithiasis is not widely studied. Methods: Urinary excretion of oxalate as well as other key factors related to urolithiasis was analyzed in a single center study of 572 patients with biopsy-proven kidney disease. Results: The mean age of the cohort was 44.9 years and 60% were males. The mean eGFR was 65.9 ml/min/1.73 m2. Median urinary excretion of oxalate was 14.7 (10.4–19.1) mg/24-h and associated with current urolithiasis (OR 12.744, 95% CI: 1.564–103.873 per one logarithm transformed unit of urinary oxalate excretion). Oxalate excretion was not associated with eGFR and urinary protein excretion. Oxalate excretion was higher in patients with ischemia nephropathy as compared with patients with glomerular nephropathy and tubulointerstitial nephropathy (16.4 vs 14.8 vs 12.0 mg, p = 0.018). And ischemia nephropathy (p = 0.027) was associated with urinary oxalate excretion on adjusted linear regression analysis. Urinary excretion of calcium and uric acid was correlated with eGFR and urinary protein excretion (all p < 0.001), with ischemia nephropathy and tubulointerstitial nephropathy associated with uric acid excretion (both p < 0.01) as well. Citrate excretion was correlated with eGFR (p < 0.001) on adjusted linear regression. Conclusion: Excretion of oxalate and other key factors related to urolithiasis was differentially associated with eGFR, urinary protein, and pathological changes in CKD patients. The influence of these intrinsic traits of the underlining kidney disease should be considered when evaluating urolithiasis risk in patients with CKD. [ABSTRACT FROM AUTHOR]

The solute-linked carrier 26 (SLC26) protein family is comprised of multifunctional transporters of substrates that include oxalate, sulphate, and chloride. Disorders of oxalate homeostasis cause hyperoxalemia and hyperoxaluria, leading to urinary calcium oxalate precipitation and urolithogenesis. SLC26 proteins are aberrantly expressed during kidney stone formation, and consequently may present therapeutic targets. SLC26 protein inhibitors are in preclinical development. In this review, we integrate the findings of recent reports with clinical data to highlight the role of SLC26 proteins in oxalate metabolism during urolithogenesis, and discuss limitations of current studies and potential directions for future research. [ABSTRACT FROM AUTHOR]

Iron pyrite has been reported as a kind of potential material for arsenic (As) removal from the groundwater because it exhibits a strong attraction in groundwater for both arsenite and arsenate species. In this study, batch adsorption experiments were carried out to determine the optimum conditions for As adsorption by the iron pyrite adsorbent, including the initial concentration, adsorbent dosage ratio, pH, temperature and stirring rate. Precisely characterization methods were employed to identify the mechanism of As removal. Maximum removal efficiency for As(III) was observed 93% at pH = 7, and for As(V) was 95% observed at pH = 5. Langmuir model resulted in the maximum adsorption capacity (qm) for As(III) and As(V) were 571.7 and 671.1 µg/g, respectively, as well as the experiments were found to be favorable as separation factor RL < 1. The value of "n" 2.68 and 2.47 for As(III) and As(V) obtained by Freundlich model (n > 1) indicates favorable adsorption. The pseudo-first and second-order kinetic models also fitted well. The addition of oxalate on the adsorbent surface plays an important role for the recycling of Fe(II)/Fe(III) to minimize the arsenic concentration. Specific surface area, ion exchange mechanism and structure of adsorbent confirmed that addition of oxalate could enhance the surface area of adsorbent. [ABSTRACT FROM AUTHOR]

Background: Primary hyperoxaluria type 1 (PH1) is an autosomal recessive disease caused by the liver defect of oxalate metabolism, which leads to kidney failure and systemic manifestations. Until recently, liver transplantation was the only definitive treatment. The timing of liver transplantation can be early, while kidney function is still normal (pre-emptive liver transplantation—PLT), or when the patient reaches stage 5 chronic kidney disease (CKD) and needs combined liver-kidney transplantation. We aimed to determine the long-term kidney outcomes of PLT in PH1 patients. Methods: A retrospective single-center study of PH1 patients who were followed in our center between 1997 and 2017. We compared the kidney outcomes of patients who underwent PLT to those who presented with preserved kidney function and did not undergo PLT. Results: Out of 36 PH1 patients, 18 patients were eligible for PLT (eGFR > 40 mL/min/1.73 m2 at the time of diagnosis). Seven patients underwent PLT (PLT group), while 11 continued conservative treatments (PLTn group). In the PLT group, the median eGFR at the time of PLT and at the end of the follow-up period (14–20 years) was 72 (range 50–89) and 104 (range 86–108) mL/min/1.73 m2, respectively, and no patient died or reached stage 5 CKD. In the PLTn group, eight patients (72.7%) reached stage 5 CKD (median time to kidney replacement therapy was 11 years), and two patients died from disease complications (18.2%). Conclusions: Pre-emptive liver transplantation preserved kidney function in patients with PH1 in our cohort. Early intervention can prevent kidney failure and systemic oxalosis in PH1. [ABSTRACT FROM AUTHOR]

Background: Coffee bean weevil (Araecerus fasciculatus DeGeer) (Coleoptera: Anthribidae) infestation is a major challenge affecting processed, dried, and stored foods globally. However, the growth performance of this insect pest in processed and stored cassava, plantain, yam, and cocoyam is poorly understood. Resolving this will guide future biotechnological efforts on these food products. In the study, the susceptibility rate of the processed and stored product of cassava, yam, cocoyam, and plantain to the growth performance of the coffee bean weevil at laboratory conditions (20 ± 5 °C and 70 ± 5% R.H.) was investigated. The anti-nutritional (phytate, alkaloids, saponin, tannin, and oxalate) contents of this stored food were used to characterize the survival rate of A. fasciculatus. The study was carried out for 6 months between December 2012 and May 2013. Results: Results show that the adult longevity, growth, and feeding of the adult A. fasciculatus decrease in order from Cassava, Plantain, Yam to Cocoyam. Cocoyam has the highest tannin, alkaloid, and phytate values, which are possible factors that inhibited the growth of the larvae, pupae, and adults' A. fasciculatus. The highest weight loss occurred in cassava followed by plantain. The anti-nutritional factors determine the hatchability of the A. fasciculatus eggs and throughout its development stages. This study revealed that processed and stored products (e.g., cocoyam) with high anti-nutritional factors can survive A. fasciculatus under prolonged storage. Conclusions: From this study, it is observed that high anti-nutritional compounds in the stored food products inhibit the growth of Araecerus fasciculatus, especially in cocoyam. The result is important in food security and management in developing countries where food insecurity has become a major challenge. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is a significant global public health concern associated with high morbidity and mortality rates. The maintenance of oxalate homeostasis plays a critical role in preserving kidney health, particularly in the context of CKD. Although the relationship between oxalate and kidney stone formation has been extensively investigated, our understanding of oxalate homeostasis in non-stone-forming CKD remains limited. This review aims to present an updated analysis of the existing literature, focusing on the intricate mechanisms involved in oxalate homeostasis in patients with CKD. Furthermore, it explores the key factors that influence oxalate accumulation and discusses the potential role of oxalate in CKD progression and prognosis. The review also emphasizes the significance of the gut–kidney axis in CKD oxalate homeostasis and provides an overview of current therapeutic strategies, as well as potential future approaches. By consolidating important findings and perspectives, this review offers a comprehensive understanding of the present knowledge in this field and identifies promising avenues for further research. [ABSTRACT FROM AUTHOR]

The stoichiometric ratio 2:1 mix of 1-phenylpiperazine and oxalic acid dihydrate followed by slow evaporation results in a new material, bis(4-phenylpiperazin-1-ium) oxalate dihydrate, with the general chemical formula (C10H15N2)2(C2O4).2H2O, indicated by PPOXH. The title compound's asymmetric unit and three-dimensional network have been determined by single crystal X-ray diffraction. Intermolecular O-H...O, N-H...O and C-H...O hydrogen bonding assist in maintaining and stabilization of the crystal structure of this new compound. Hirshfeld surface analysis and two-dimensional fingerprints have been performed to quantify the non-covalent interactions in the PPOXH structure. The vibrational modes of the different characteristic groups of the title chemical were identified using infrared spectrum analysis. The thermal characterization of this product was studied by a coupled TG/DTA analysis. The ultraviolet-visible absorption spectrum has been used to study the optical properties and the energy gap of this compound. DFT calculations were employed to evaluate the composition and properties of PPOXH. The analysis of HOMO-LUMO frontier orbitals analysis allows us to understand the chemical reactivity of this supramolecular compound and to determine the electrophilic and nucleophilic sites responsible for electron transfer. Topological analysis (AIM), reduced density gradient (RDG), molecular electrostatic potential surface (MEPS) and Mulliken population were analyzed to evaluate the types of non-covalent interactions, localization of electrons in space, atomic charges and molecular polarity in depth. [ABSTRACT FROM AUTHOR]

Annexin A1 (ANXA1) is a multifunctional calcium-binding protein that can bind to membrane phospholipids. Under high-calcium condition, ANXA1 expression increases on renal epithelial cell surface, leading to enhanced adhesion of calcium oxalate (CaOx) crystal (stone material) onto the cells. To regulate various cellular processes, ANXA1 interacts with many other intracellular protein partners. However, components of the ANXA1-interacting protein complex remain unclear. Herein, we characterized the interacting complexes of apical membrane (ApANXA1) and cytosolic (cyANXA1) forms of ANXA1 in apical membrane and cytosolic compartments, respectively, of renal epithelial cells under high-calcium condition using proteomic and bioinformatic approaches. After fractionation, the ApANXA1- and CyANXA1-interacting partners were identified by immunoprecipitation followed by nanoLC‑ESI‑Qq-TOF tandem mass spectrometry (IP-MS/MS). The ANXA1-interacting partners that were common in both apical membrane and cytosolic compartments and those unique in each compartment were then analyzed for their physico-chemical properties (molecular weight, isoelectric point, amino acid contents, instability index, aliphatic index, and grand average of hydropathicity), secondary structure (α-helix, β-turn, random coil, and extended strand), molecular functions, biological processes, reactome pathways and KEGG pathways. The data demonstrated that each set of these interacting proteins exhibited common and unique characteristics and properties. The knowledge from this study may lead to better understanding of the ApANXA1 and CyAXNA1 biochemistry and functions as well as the pathophysiology of CaOx kidney stone formation induced by high-calcium condition.

Abstract Oxidative stress damage to renal epithelial cells is the main pathological factor of calcium oxalate calculi formation. The development of medicine that could alleviate oxidative damage has become the key to the prevention and treatment of urolithiasis. Herein, porous nanorods CeO2 nanoparticles (CNPs) were selected from CeO2 with different morphologies as an antioxidant reagent to suppress kidney calcium oxalate crystal depositions with excellent oxidation resistance due to its larger specific surface area. The reversible transformation from Ce3+ to Ce4+ could catalyze the decomposition of excess free radicals and act as a biological antioxidant enzyme basing on its strong ability to scavenge free radicals. The protection capability of CNPS against oxalate-induced damage and the effect of CNPS on calcium oxalate crystallization were studied. CNPS could effectively reduce reactive oxygen species production, restore mitochondrial membrane potential polarity, recover cell cycle progression, reduce cell death, and inhibit the formation of calcium oxalate crystals on the cell surface in vitro. The results of high-throughput sequencing of mRNA showed that CNPs could protect renal epithelial cells from oxidative stress damage caused by high oxalate by suppressing the expression gene of cell surface adhesion proteins. In addition, CNPS can significantly reduce the pathological damage of renal tubules and inhibit the deposition of calcium oxalate crystals in rat kidneys while having no significant side effect on other organs and physiological indicators in vivo. Our results provide a new strategy for CNPS as a potential for clinical prevention of crystalline kidney injury and crystal deposition.

Abstract Background The potential effects of dietary oxalate (Ox) intake on cardio-renal function have remained unestablished. We evaluated the effect of usual Ox intake and its interaction with dietary calcium (Ca) on incident hypertension (HTN) and chronic kidney disease (CKD). Methods Adult men and women, free of HTN and CKD at baseline (2006–2008), were recruited. Dietary intakes were assessed using a validated food frequency questionnaire, and the outcomes were documented up to 2014–2017. Multivariate Cox proportional hazard regression models were used to estimate the development of HTN and CKD in relation to Ox intakes. Repeated-measures generalized estimating equation (GEE) linear regression models were used to assess possible effect of Ox-intake on the estimated glomerular filtration rate (eGFR) and blood pressure levels over eight years. Results Dietary Ox intakes were positively associated with incident CKD (HR = 2.59, 95% CI = 1.46–4.64) and HTN (HR = 1.79, 95% CI = 1.05–3.04). Compared to high-Ca consumers, subjects who had lower Ca intakes ( 220 vs.

Oxalate serves various functions in the biological processes of plants, fungi, bacteria, and animals. It occurs naturally in the minerals weddellite and whewellite (calcium oxalates) or as oxalic acid. The environmental accumulation of oxalate is disproportionately low compared to the prevalence of highly productive oxalogens, namely plants. It is hypothesized that oxalotrophic microbes limit oxalate accumulation by degrading oxalate minerals to carbonates via an underexplored biogeochemical cycle known as the oxalate-carbonate pathway (OCP). Neither the diversity nor the ecology of oxalotrophic bacteria is fully understood. This research investigated the phylogenetic relationships of the bacterial genes oxc, frc, oxdC, and oxlT, which encode key enzymes for oxalotrophy, using bioinformatic approaches and publicly available omics datasets. Phylogenetic trees of oxc and oxdC genes demonstrated grouping by both source environment and taxonomy. All four trees included genes from metagenome-assembled genomes (MAGs) that contained novel lineages and environments for oxalotrophs. In particular, sequences of each gene were recovered from marine environments. These results were supported with marine transcriptome sequences and description of key amino acid residue conservation. Additionally, we investigated the theoretical energy yield from oxalotrophy across marine-relevant pressure and temperature conditions and found similar standard state Gibbs free energy to "low energy" marine sediment metabolisms, such as anaerobic oxidation of methane coupled to sulfate reduction. These findings suggest further need to understand the role of bacterial oxalotrophy in the OCP, particularly in marine environments, and its contribution to global carbon cycling. [ABSTRACT FROM AUTHOR]

Under the hydrothermal method, a Pb(II) coordination polymer [Pb(ox)(phen)2]·5H2O 1 (ox = oxalate, phen = 1,10-phenanthroline) was obtained. Ox ligands exhibit a μ2-coordination mode, which connect Pb2+ centers into a 1-D single-chain with ancillary phen molecules. Interestingly, adjacent phen molecules between the chains exist π…π stacking interaction, which extend the 1-D chain into a 2-D supramolecular layer. Compound 1 showed outstanding photocatalytic performance and the degradation efficiency of methylene blue with H2O2 could reach 95.69% under the irradiation of visible light at pH = 10. In addition, 5 cycles of degradation experiments were also carried out, and it was found that the degradation efficiency values with and without H2O2 were reduced by 1.46% and 1.08%, respectively. It was also discussed that which free radical played the dominant role in the photocatalytic process. What’s more, we speculated the possible reaction mechanism based on the Mott–Schottky curve. Meanwhile, the UV visible diffuse reflection of compound 1 was also investigated. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to help patients with calcium oxalate stones to access prevention and treatment options with dietary management. Methods: Typical cases in our hospital and other hospitals were selected for case review; combined with literature review through PubMed search, comprehensive analysis and suggestions were put forward. Results: By retrieving the literature with sufficient evidence, selecting, and summarizing, analysis of dietary liquid, oxalate and oxalate precursors, calcium, protein, fruits and vegetables, salt, high dietary fiber, and other content with high evidence index was carried out, respectively. Conclusion: Through the retrospective analysis of typical cases and literature review, the importance of diet management in the prevention and treatment of calcium oxalate stones was emphasized again, and suggestions were put forward to promote the prevention and treatment of calcium oxalate stones. [ABSTRACT FROM AUTHOR]

When referring to the influence of environmental factors in urinary lithiasis, usually heat exposure is the primary etiologic factor, underestimating the soil in which the plants are cultivated or water characteristics, the main sources of patients’ nutrition. In this retrospective study, we analyzed the correlations between the patients’ nutrition, the composition of the stones and the risk of lithiasis recurrence. We analyzed data from 390 stones collected between 2019 and 2022. The composition of the stones was determined by infrared spectroscopy (FTIR), and the evaluation of the patients’ nutrition was quantified by the LAMPA questionnaire. We found that for patients with calcium oxalate dihydrate lithiasis, the most important dietary risk factor in the occurrence of recurrence is represented by excessive salt consumption (risk five times higher for patients 18-30 years old, 21 times higher for patients 31-40 years old and 16 times higher for patients 51-60 years old). We also noticed that this crystalline species is associated with the dietary excess of bread (for patients 18-30 years old), potatoes (9.5 times higher risk for patients 18-30 years old and 5.5 times higher risks for patients 41-50 years old) and with the excessive consumption of animal proteins (3.54 times higher risk for patients aged 41-50). In patients with calcium oxalate monohydrate lithiasis, the frequent consumption of potatoes was associated with a 13 times higher risk of developing lithiasis recurrence (in patients 31-40). Other important risk factors for this type of stone are represented by alcohol (8 times higher risk for patients aged 31-40 and 20.4 times higher for patients aged 51-60), and protein consumption (5 times higher risk for patients aged 51-60). [ABSTRACT FROM AUTHOR]

Two one-dimensional oxalate-bridged Cu(II) ammonium salts, [(CH3)3NH]2[Cu(μ-C2O4)(C2O4)]·2.5H2O (I) and [(C2H5)3NH]2[Cu(μ-C2O4)(C2O4)]·H2O (II) were obtained and characterized. They were composed of ammonium: (CH3)3NH+ in (I), (C2H5)3NH+ in (II), [Cu(μ-C2O4)(C2O4)2−]n and H2O. The Jahn–Teller-distorted Cu(II) is octahedrally coordinated by six O atoms from three oxalates and forms a one-dimensional zigzag chain. The hydrogen bonds between ammonium, the anion and H2O form a three-dimensional network. There is no hydrogen bond between the anion chains. They were insulated at 20 °C with a relative humidity of 40%. Ferromagnetic and weak-ferromagnetic behaviors were observed in I and II, separately. No long-range ordering was observed above 2 K. [ABSTRACT FROM AUTHOR]

Oxalate is a divalent organic anion that affects many biological and commercial processes. It is derived from plant sources, such as spinach, rhubarb, tea, cacao, nuts, and beans, and therefore is commonly found in raw or processed food products. Oxalate can also be made endogenously by humans and other mammals as a byproduct of hepatic enzymatic reactions. It is theorized that plants use oxalate to store calcium and protect against herbivory. Clinically, oxalate is best known to be a major component of kidney stones, which commonly contain calcium oxalate crystals. Oxalate can induce an inflammatory response that decreases the immune system's ability to remove renal crystals. When formulated with platinum as oxaliplatin (an anticancer drug), oxalate has been proposed to cause neurotoxicity and nerve pain. There are many sectors of industry that are hampered by oxalate, and others that depend on it. For example, calcium oxalate is troublesome in the pulp industry and the alumina industry as it deposits on machinery. On the other hand, oxalate is a common active component of rust removal and cleaning products. Due to its ubiquity, there is interest in developing efficient methods to quantify oxalate. Over the past four decades, many diverse methods have been reported. These approaches include electrochemical detection, liquid chromatography or gas chromatography coupled with mass spectrometry, enzymatic degradation of oxalate with oxalate oxidase and detection of hydrogen peroxide produced, and indicator displacement-based methods employing fluorescent or UV light-absorbing compounds. Enhancements in sensitivity have been reported for both electrochemical and mass-spectrometry-based methods as recently as this year. Indicator-based methods have realized a surge in interest that continues to date. The diversity of these approaches, in terms of instrumentation, sample preparation, and sensitivity, has made it clear that no single method will work best for every purpose. This review describes the strengths and limitations of each method, and may serve as a reference for investigators to decide which approach is most suitable for their work. [ABSTRACT FROM AUTHOR]

Proximal tubular (PT) cells reabsorb most calcium (Ca2+), phosphate (PO43−), bicarbonate (HCO3−), and oxalate (C2O42−) ions. We have shown that mice lacking Transient Receptor Potential Canonical 3 (TRPC3−/−) channel are moderately hypercalciuric with presentation of luminal calcium phosphate (CaP) crystals at the loop of Henle (LOH). However, other predisposing factors for such crystal deposition are unknown. Thus, we examined the distinctions in functional status of HCO3−, PO43−, and C2O42− transporters in PT cells of wild type (WT) and TRPC3−/− mice by whole‐cell patch clamp techniques to assess their contribution in the development of LOH CaP crystals. Here we show the development of concentration dependent HCO3−‐induced currents in all PT cells, which was confirmed by using specific HCO3− channel inhibitor, S0859. Interestingly, such activities were diminished in PT cells from TRPC3−/− mice, suggesting reduced HCO3− transport in absence of TRPC3. While PO43−‐induced currents were also concentration dependent in all PT cells (confirmed by PO43− channel inhibitor, PF‐06869206), those activities were reduced in absence of TRPC3, suggesting lower PO43− reabsorption that can leave excess luminal PO43−. Next, we applied thiosulfate (O3S22−) as a competitive inhibitor of the SLC26a6 transporter upon C2O42− current activation and observed a reduced C2O42−‐induced conductance which was greater in TRPC3−/− PT cells. Together, these results suggest that the reduced activities of HCO3−, PO43−, and C2O42− transporters in moderately hypercalciuric (TRPC3−/−) PT cells can create a predisposing condition for CaP and CaP tubular crystallization, enabling CaP crystal formation in LOH of TRPC3−/− mice. [ABSTRACT FROM AUTHOR]

Background: Grape seed extract (GSE) has demonstrated various pharmacological actions. Urolithiasis is the occurrence of calculus in the renal system. The present study evaluated the anti-urolithic effect of GSE on ethylene glycol (EG) and ammonium chloride (AC)-induced experimental urolithiasis in rats. Materials and Methods: Rats were assigned into six groups; Normal control and Normal + GSE, in which rats received standard drinking water and GSE orally daily, respectively; Urolithiatic animals received EG with AC in drinking water for 28 days; Urolithiatic animals + GSE, in which rats were administered EG with AC in drinking water and GSE 100 and 200 mg/kg orally; and Urolithiatic + cystone, where rats received EG with AC in drinking water and 750 g/kg of cystone as a standard drug orally. Results: Urolithiatic animals showed a significant decrease in excreted magnesium and citrate and antioxidant enzymes, whereas they exhibited amplified oxalate crystal numbers, urinary excreted calcium, phosphate, oxalate ions, uric acid, intensified renal function parameters, lipid peroxidation, and inflammatory mediators. Management with GSE and cystone significantly augmented urolithiasis inhibitors (excreted magnesium and citrate) and amplified the antioxidant enzymes' activities. GSE reduced oxalate crystal numbers and urolithiasis promoters, including excreted calcium, oxalate, phosphate, and uric acid excretion, lessened renal function parameters, and declined lipid peroxidation and the inflammatory mediators. Conclusion: GSE could protect against EG-induced renal stones as evidenced by mitigated kidney dysfunction, histological alterations, and oxalate crystal formation. This action may be related to the antioxidant as well as anti-inflammatory activities of the extracts. [ABSTRACT FROM AUTHOR]

Abstract The iron‐based polyanionic fluoro‐oxalate material, KFe(C2O4)F (KFCF), has been synthesized by hydrothermal methods. This compound shows promising reversible lithium and sodium insertion properties as a cathode material. The material delivered a first‐cycle discharge capacity of 120 mAh g−1 at ∼3.3 V (Li+/Li) and 97.4 mAh g−1 at ∼3.0 V (Na+/Na) in LIB and NIB, respectively. Stable cycling performance was observed in both cases. The involvement of reversible Fe2+/Fe3+ redox was confirmed by ex‐situ Mössbauer spectroscopy supported by first‐principles calculations. This study reveals promising performance from a mixed oxalate‐fluoride based polyanionic material thereby opening up further possibilities for materials discovery in the design of new electrode materials.

Aim of study: Humic substances (HS) have an impact on the dynamics of phosphorus (P) and zinc (Zn) in soil and consequently can affect the availability of both nutrients to plants. This work aimed to study the effect of humic substances on the availability of P and Zn to wheat depending on the main sorbent surfaces in growth media. Area of study: Growth chambers of the Higher Technical School of Agricultural Engineering, University of Seville, Spain Material and methods: To this end, a pot experiment was performed involving three factors: i) HS rates, ii) Zn fertilization, and iii) type of growth medium, calcareous and noncalcareous (siliceous). Main results: Biomass production and Zn uptake by plants decreased with increasing HS rates. Humic substances decreased Zn uptake more markedly in the siliceous medium. Negative effects of HS can be ascribed to altered crop nutrition and the high aromaticity of HS that can promote phytotoxic effects. The antagonistic effect between P and Zn was less evident in the calcareous medium than in the siliceous medium. This is probably explained by the reduced availability of Zn and the consequent decrease in uptake by plants in the calcareous medium compared to the siliceous medium. These differences observed between both media can be ascribed to different adsorption dynamics depending on the main sorbent surfaces. Research highlights: The addition of HS, at the intermediate rates studied, had a positive effect on the microbial activity of the rhizosphere in the calcareous medium. Thus, not only crop functioning, but also soil biology, can be affected by the application of HS. This effect can be different depending on the HS rates applied and the type of growth medium.

Kidney stones are among the most prevalent urological diseases, with a high incidence and recurrence rate. Treating kidney stones has been greatly improved by the development of various minimally invasive techniques. Currently, stone treatment is relatively mature. However, most current treatment methods are limited to stones and cannot effectively reduce their incidence and recurrence. Therefore, preventing disease occurrence, development, and recurrence after treatment, has become an urgent issue. The etiology and pathogenesis of stone formation are key factors in resolving this issue. More than 80% of kidney stones are calcium oxalate stones. Several studies have studied the formation mechanism of stones from the metabolism of urinary calcium, but there are few studies on oxalate, which plays an equally important role in stone formation. Oxalate and calcium play equally important roles in calcium oxalate stones, whereas the metabolism and excretion disorders of oxalate play a crucial role in their occurrence. Therefore, starting from the relationship between renal calculi and oxalate metabolism, this work reviews the occurrence of renal calculi, oxalate absorption, metabolism, and excretion mechanisms, focusing on the key role of SLC26A6 in oxalate excretion and the regulatory mechanism of SLC26A6 in oxalate transport. This review provides some new clues for the mechanism of kidney stones from the perspective of oxalate to improve the understanding of the role of oxalate in the formation of kidney stones and to provide suggestions for reducing the incidence and recurrence rate of kidney stones.

Convenient and highly sensitive detection of oxalate ions in body fluids is of crucial significance for disease prevention, diagnosis, and monitoring of treatment effectiveness. Establishing a simple solid-state electrochemiluminescence (ECL) sensing system for highly sensitive detection of oxalate ions is highly desirable. In this work, a solid ECL sensor was fabricated by immobilizing the commonly used emitter ruthenium(II)tris(bipyridine) (Ru(bpy)32+) on a double-layered bipolar silica nanochannel array film (bp-SNA)-modified electrode, enabling sensitive detection of oxalate ions in serum or urine samples. Cost-effective and readily available indium tin oxide (ITO) was used as the supporting electrode. Convenient fabrication of multiple negatively charged SNA (n-SNA)-modified ITO electrodes was achieved through the one-step Stöber solution growth method. Subsequently, a positive outer layer film (p-SNA) was rapidly prepared using an electrochemical-assisted self-assembly method. The double-layered bipolar silica nanochannel array film achieved stable immobilization of Ru(bpy)32+ on the electrode surface, facilitated by the electrostatic adsorption of Ru(bpy)32+ by n-SNA and the electrostatic repulsion by p-SNA. Utilizing oxalate ions as a co-reactant for Ru(bpy)32+, combined with the electrostatic enrichment of oxalate ions by p-SNA, the constructed sensor enabled highly sensitive detection of oxalate ions ranging from 1 nM to 25 μM and from 25 μM to 1 mM, with a detection limit (LOD) of 0.8 nM. The fabricated ECL sensor exhibited high selectivity and good stability, making it suitable for ECL detection of oxalate ions in serum and urine samples.