Citrate Solution Research Articles

Simultaneous determination of five triarylmethane colorants in syrup by applying multivariate curve resolution to second-derivative visible absorption spectra.

A method for the simultaneous determination of five triarylmethane colorants (brilliant blue FCF, patent blue V, patent blue VF, fast green FCF, and green S) in syrup samples was proposed by applying multivariate curve resolution to second-derivative visible absorption spectra in citrate and carbonate buffer solutions. Even for heavily overlapping spectra, adopting second-derivative spectra and multiway analysis in citrate and carbonate buffer solutions enhanced specificity for the analytes and achieved prediction performance with a coefficient of determination (R2) > 0.90, root mean square error of prediction (RMSEP) < 0.20mg/L, and limit of detection (LOD) < 0.50mg/L for all five analytes. The basis set expansion method succeeded in a reasonable estimation of the second-derivative spectra with the interferant. For commercial syrup samples, the present method predicted results without significant differences compared to the results measured using liquid chromatography-mass spectrometry. The proposed method provides a rapid alternative to liquid chromatography techniques for the quantification of multiple colorants in food samples.

Evaluation of Effects of Various Irrigating Solutions on Chemical Structure of Root Canal Dentin Using FTIR, SEM, and EDS: An In Vitro Study.

Background: Sequential chemical application for irrigating a root canal during chemomechanical debridement can affect the dentin microstructure. Understanding the effects of various irrigants on chemical properties of dentin can elucidate their effects on physical properties and thereby explain the higher incidence of structural failure in endodontically treated teeth. This in vitro research aimed to compare and evaluate the effects of three different irrigating solutions on the chemical structure of root canal dentin in extracted human teeth. Methods: Forty-eight extracted single-rooted mandibular premolar teeth were sectioned at the cemento–enamel junction by a diamond disc and were then randomly assigned to four groups of twelve samples each. The groups were irrigated using 5.25% NaOCl, ozonated olive oil, silver citrate, or distilled water. Dentin sections measuring 1.5 mm were obtained from the root portion and each section and were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and electron-dispersive spectroscopy (EDS). FTIR and EDS values are reported as means ± standard deviations. Data were analyzed using an ANOVA and a post hoc Bonferroni test (p < 0.05). Results: A comparison of the FTIR and EDS values among the groups using ANOVA revealed statistically significant differences in the organic and inorganic peak values among the groups. An intergroup comparison between NaOCl with silver citrate and ozonated olive oil revealed significant reductions in the carbonate and phosphate peak values in the NaOCl group (p < 0.05). The EDS values tabulated for the carbon, oxygen, phosphorous, and calcium peak levels showed significant differences between the groups using an ANOVA. An SEM analysis was conducted under 1500× magnification, which revealed smear layer removal in the silver citrate group. Conclusions: The silver citrate solution and the ozonated olive oil caused less changes in the organic and mineral contents of dentin than sodium hypochlorite.

Self-nanoemulsifying formulation for oral delivery of sildenafil: effect on physicochemical attributes and in vivo pharmacokinetics.

Sildenafil (SLD) is employed for the management of erectile dysfunction and pulmonary arterial hypertension. It exhibits meagre water solubility and is available in the form of citrate salt hydrate to improve the solubility. However, it still exhibits moderate solubility, high first-pass metabolism, resulting in very less oral bioavailability. The present study demonstrates the preparation of self-nanoemulsifying drug delivery system for augmenting the oral bioavailability of SLD. Oleic acid and Capmul MCM C8 blend (oil phase), Cremophor® RH40 (surfactant), and Labrafil® M1944 CS (cosurfactant) were selected as main constituents for making liquid preconcentrate based on the solubility and emulsification study. The preconcentrate upon dilution and emulsification showed droplet size 52.03 ± 13.03nm, PDI 0.143 ± 0.028, and % transmittance was 99.77 ± 1.86% with SLD load of 40mg/g of formulation. The prepared formulation was further assessed for stability, in vitro release, Caco-2 cell uptake, and in vivo pharmacokinetic performance. SLD-SNEDDS formulation was found to be robust in terms of stability against several folds dilution in the gastrointestinal tract (GIT), freeze-thaw cycles, and had a storage stability of 3months at 4°C and 25°C. SLD-SNEDDS showed ~4.7-fold and ~5-fold increase in time- and concentration-dependent cellular uptake as against SLD cultured with Caco-2 cells. In vivo pharmacokinetic study revealed ~5.8- and ~2.5-fold increase in AUC0-∞ values in case of SLD-SNEDDS as against SLD suspension and SLD citrate solution, respectively.

The Efficacy of Taurolidine Citrate Solution v Heparin Lock Solution Instilled in Catheter Lumens of End Stage Renal Disease

Background: Hemodialysis patients with end-stage renal illness use a tunnelled central vein catheter for vascular access. Heparin with a preservative, in contrast, exhibits inferior antibacterial effects against biofilm and plank tonic bacteria. Aim: To evaluate the effectiveness of taurolidine citrate solution versus heparin lock solution when infused into the catheter lumens of hemodialysis patients with end-stage renal illness. Study design: Randomized clinical trial Place and duration of study: Hemodialysis Unit, King Fahad Specialist Hospital, Buraidah, Saudi Arabia from 11th December 2018 to 10th June 2019. Methodology: One hundred and fourteen patients on hemodialysis aged 40-70 years with end stage renal disease with Glomerular filtration rate (GFR) less than 15 mL/min, on maintenance hemodialysis through tunnelled dialysis catheter dependent for at least 6 months and patent catheters were selected and randomized into two equal groups by using sealed opaque envelopes bearing a tag of Heparin group and citrate-taurolidine group. Patients were excluded from the study if they had a catheter site infection or an infection unrelated to a catheter that was on antibiotic therapy or had positive blood cultures within two weeks of enrollment. Every two weeks and at the time the catheter was removed, blood cultures were routinely obtained from the catheter lumen to look for bacterial colonization. At the conclusion of six months of hemodialysis, the CRI was assessed. All instances of infections caused by catheters were documented. Results: Incidence of catheter related infection occurred in 5 (8.8%) patients who underwent Heparin group while none of the patient (0%) of taurolidine/citrate group suffered with catheter related infection. This data reveals significantly high incidence of CRI in Heparin group (p=0.029) and significantly high efficacy of taurolidine/citrate group over Heparin group. Conclusion: Efficacy of taurolidine citrate solution is superior versus heparin lock solution instilled in the catheter lumens of patients on hemodialysis. Keywords: Catheter, Infection, Renal disease, Hemodialysis

Comments on “Investigation of the inter-ionic interactions of an imidazolium-based ionic liquid with the aqueous solutions of tripotassium citrate and trisodium citrate through volumetric, acoustic and FTIR routes”

A polemic is given concerning the volumetric properties reported for binary aqueous-1-butyl-3-methylimidazolum chloride mixtures in the published paper by Pattanaik and coworkers. The reported limiting values of the apparent molal volumes of 1-butyl-3-methylimidazolium differ significantly from the published literature values of ten independent research groups. Reported limiting values of the apparent molal volumes of trisodium citrate and tripotassium citrate in water were also found to differ significantly from published literature values.

Strontium-loaded hydrogel scaffolds to promote gingival fibroblast function.

Dental implant clinical success is dependent on effective peri-implant tissue attachment to the trans-mucosal portion following placement. Modification of transmucosal implant surfaces can improve cellular adhesion and function leading to formation of an effective soft-tissue seal during healing, of which gingival fibroblasts are prominent cells to migrate to repair wounds and crucial for the development of a collagen rich connective tissue. Biocompatible loaded scaffold materials have been developed to allow local release of molecules with effective biological activity. Our previous studies indicate that strontium can promote gingival fibroblast metabolism, decrease apoptosis and support adhesion to titanium healing abutments. In this study, we developed a strontium-loaded alginate hydrogel scaffold which can be easily personalized to fit over any size and shape of implant transmucosal collar or healing abutment. Results indicate that biologically active strontium ions are effectively released from loaded alginate hydrogel material to promote fibroblast viability and migration to repair in vitro wounds similar to that of strontium citrate solution. Overall, this novel strontium-loaded alginate scaffold device displays good biocompatibility and functionality, demonstrating high potential as a system to provide local delivery of strontium to improve peri-implant mucosal healing following implant placement and clinical success.

The effect of sodium citrate on NaOH-activated BFS cement: Hydration, mechanical property, and micro/nanostructure

This paper presents a study on the effect of sodium citrate solution (0.25M, 0.5M, 0.75M) on the hydration process and microstructure evolution of NaOH-activated blast furnace slag (BFS) paste. The setting behavior, flowability, mechanical strength, hydration kinetics, and micro/nanostructure characteristics were investigated through multiple tests—such as Vicat test, mini-slump test, x-ray diffraction, spectroscopy analysis, nuclear magnetic resonance, and mercury intrusion porosimetry—to reveal the hydration mechanism of NaOH-activated BFS paste in presence of sodium citrate. The results indicate that the citrate ions retarded the hydration process and contributed significantly to slag dissolution and precipitation of hydration products during the alkali-activated reaction process. The microstructure build-up from the early stage (3 days) to the mature stage (28 days) underwent a different process, resulting in a more densified and less porous matrix with higher compressive strength. However, no significant changes were observed in the type of hydration products and their nanostructural characteristics.

Effect of Plasmonic Au and Ag/Au Nanoparticles and Sodium Citrate on the Optical Properties of Chitin-Based Photonic Nanoarchitectures in Butterfly Wing Scales

Porous butterfly wings with hierarchically organized structures from nanometer to centimeter scales were tested as substrates for carrying plasmonic Au and Ag/Au nanoparticles with potential application in photocatalysis. Wings exhibiting structural color generated by chitin-air nanocomposites were used. Hundreds of butterfly species possess these types of color-generating photonic nanoarchitectures, producing color by a similar mechanism to manmade photonic crystals. Artificial photonic crystals are known to enhance photocatalytic processes through the slow light effect. The impact of pure water, water-based sodium citrate solution, and Au and Ag/Au alloy nanoparticles on the optical properties of the natural photonic structures were separated. While water and aqueous sodium citrate solutions change the wing reflectance by the alteration of the wing scale position with respect to the wing plane, Au and Ag/Au alloy nanoparticles form a new, hybrid nanostructure with the chitin nanoarchitecture modifying the structural color of the butterfly wings. The optical properties of the new types of hybrid photonic nanoarchitectures (consisting of butterfly wings and plasmonic nanoparticles) are different from those of the components.

Efecto del proceso de equilibrio en espermatozoides caninos después de la vitrificación con dilutor a base de agua de coco con adición de lecitina de soya y sacarosa como crioprotectores no permeables

The aim of the present study was to evaluate the effect of equilibration process on canine sperms after vitrification using coconut water extender with addition of soy lecithin and sucrose as nonpermeable cryoprotectants. Twelve ejaculates were collected separately by digital manipulation from 12 adult dogs. Only the second fraction of the ejaculate was used in this study, which was evaluated about volume, concetration, viability, total and progressive motility, kinetic parameters and morphology. After evaluation, semen was diluted with a coconut water extender (50% coconut water (v/v), 25% (v/v) distilled water and 25% (v/v) 5% anhydrous monosodium citrate solution) with addition of soy lecithin and fructose at 1% (v/v) and 0.25 M sucrose until final concentration of 100x106 spermatozoa/ml. Samples were divided into three aliquots and each of them was processed at different regimens: without equilibration, 5ºC for 30 minutes and 5ºC for 60 minutes and then vitrified by dropping 30 μl of sperm suspension directly into liquid nitrogen. Sperm pellets were devitrified at least one week later as three of them were dropped into 0.3 mL of CaniPlus AI (Minitüb, Germany), which was previously warmed in a water bath at 37ºC for 2 minutes. Sperm concentration and motility parameters were assayed using a computer-aided sperm analysis (CASA) system, viability-by supravital staining technique and morphology parameters were evaluated in Haemacolor® stained semen samples. In conclusion, our results demonstrate that when vitrification and coconut water extender with addition of 1% soy lecithin and 0.25 M sucrose as cryoprotectants were used, presence of equilibration time of 60 minutes returned the best canine sperm quality results.

Blood parameters of rabbits given different amounts of iodine citrate

The need for iodine in rabbit diets has not been fully elucidated, although some commercial diets use it in varying amounts without scientific justification. The main goal of the experiment was to establish the effect of applied quantities of an organic iodine compound produced by nanotechnology – iodine citrate – on blood parameters of rabbits after weaning from 40 to 96 days of age. Experimental studies were conducted in the conditions of the vivarium of the scientific institution – Institute of Animal Biology of the National Academy of Sciences of Lviv on 30 rabbits of the Termonska breed. The control and experimental groups had the same number of 6 animals, of which 3 were males and 3 were females. Young rabbits of the control group were kept on standard granulated compound feed and water without restriction. In contrast to the control, the animals of I, II, III, and IV experimental groups additionally received a solution of iodine citrate in the amount of 2.5; 3.75; 5.0 and 7.5 μg/l of water, respectively. Blood parameters were determined on the 40th day of life (preparatory period) and on the 18th, 43rdБ and 56th days of iodine citrate supplementation. Studies have established a higher number of red blood cells and haemoglobin concentration in the blood of rabbits of Group II (P≤0.05) on the 43rd and 56th days; Group III (P≤0.05) and Group IV (P≤0.05-0.01) on the 18th, 43rd, and 56th days of the study. The haematocrit value of the blood of rabbits of Group II was respectively higher by 16.6% on the 56th day; Group III – by 17.1%; 20.0%, and 22.8%, and in Group IV – by 26.4%; 29.4%, and 23.5% on the 18th, 43rd, and 56th days of the study. The albumin content in the blood of rabbits of Group I was higher by 4.1% on the 43rd day; Group II – by 6.8%; 8.0%; 9.5%; Group III – by 6.1%; 4.6%; 9.5%; Group IV – by 4.5%; 2.7%; 7.3% on the 18th, 43rd, and 56th days of the study, respectively. The content of total calcium in the blood of rabbits of Group II exceeded the control by 22.5% on day 43, the level of inorganic phosphorus in the blood of rabbits of Groups II, III, and IV was respectively higher by 5.8%, 5.0%, and 4.1% on the 56th day of the study compared to the control.

Alkali treatment–acid leaching of rare earth elements from phosphogypsum fertilizer: insight for additional resource of valuable components

Phosphogypsum (PG) is the main by-product of phosphoric acid, which is produced by the sulfuric acid attack of phosphate rocks, wet process. This by-product, which contains around 2.0% phosphoric acid, is used as a low-cost soil fertilizer, PGF. PGF consists mainly of gypsum (CaSO4·2H2O), P2O5, SiO2, and other impurities, including a minor amount of rare earth elements, REEs. In general, phosphate rocks contain from about 0.04 to 1.0% REE, which are precipitated with PG. Now, REEs are considered as strategic elements. Therefore, PG is now regarded as a secondary source of REE. This paper address a process for the separation of REEs and sodium sulphate as a product from PGF. This paper is based on the metathesis of the bulk of PGF with sodium carbonate to obtain calcium carbonate precipitated contain REEs. Furthermore, sodium sulphate was obtained as a product. Calcium carbonate containing REEs was leached out by citric acid as a green acid or nitric acid. At optimum conditions, maximum leaching of REEs from CaCO3 after one cycle of leaching by 3.0 mol/L nitric acid at L/S = 3/1, agitation time of 180.0 min., and at a temperature of 25 °C is 75.1%, 361.10 mg/kg from the total REEs present in PGF. While, the maximum leaching of 87.4%, 420.2 mg/kg of REEs from CaCO3 after one cycle of leaching by 1.0 mol/L citric acid, L/S = 5/1, agitation time of 15.0 min., and 85 °C. The REEs that were obtained in the leaching citrate solutions were purified by solvent extraction using 10% of di-2-ethyl hexyl phosphoric acid, HDEHP, in kerosene. The extracted REEs were stripped by 0.5 mol/L H2SO4. The stripped solutions were further treated with 10.0% oxalic acid to precipitate the REEs. The developed procedure can recover REEs from PGF with an efficiency of 85.2% and a purity of 97.7%.

Establishment and Optimization of Molecular Cytogenetic Techniques (45S rDNA-FISH, GISH, and Fiber-FISH) in Kiwifruit (Actinidia Lindl.).

The kiwifruit (Actinidia chinensis) has long been regarded as “the king of fruits” for its nutritional importance. However, the molecular cytogenetics of kiwifruit has long been hampered because of the large number of basic chromosome (x = 29), the inherent small size and highly similar morphology of metaphase chromosomes. Fluorescence in situ hybridization (FISH) is an indispensable molecular cytogenetic technique widely used in many plant species. Herein, the effects of post-hybridization washing temperature on FISH, blocking DNA concentration on genomic in situ hybridization (GISH), extraction method on nuclei isolation and the incubation time on the DNA fiber quality in kiwifruit were evaluated. The post-hybridization washing in 2 × saline sodium citrate (SSC) solution for 3 × 5 min at 37°C ensured high stringency and distinct specific FISH signals in kiwifruit somatic chromosomes. The use of 50 × blocking DNA provided an efficient and reliable means of discriminating between chromosomes derived from in the hybrids of A. chinensis var. chinensis (2n = 2x = 58) × A. eriantha (2n = 2x = 58), and inferring the participation of parental genitors. The chopping method established in the present study were found to be very suitable for preparation of leaf nuclei in kiwifruit. A high-quality linear DNA fiber was achieved by an incubation of 20 min. The physical size of 45S rDNA signals was approximately 0.35–0.40 μm revealed by the highly reproducible fiber-FISH procedures established and optimized in this study. The molecular cytogenetic techniques (45S rDNA-FISH, GISH, and high-resolution fiber-FISH) for kiwifruit was for the first time established and optimized in the present study, which is the foundation for the future genomic and evolutionary studies and provides chromosomal characterization for kiwifruit breeding programs.

Effect of storage temperature and time on erythrocyte sedimentation rate

ObjectiveThis paper explores the effect of blood sample storage temperature and time on the erythrocyte sedimentation rate (ESR) by using the Weiss method.MethodsWhole blood samples were collected from 80 patients and diluted 1:9 with sodium citrate solution. Each sample was split into two tubes. Using the Weiss method, ESR was tested within 1 h of collection, and one sample was placed at 4 °C and the other at room temperature (23 ± 2 °C). ESR was then measured at 2, 4, 6, 8, 12, and 24 h. The data were statistically analyzed with consideration for temperature and time.ResultsESR decreased gradually over 6 h at room temperature, but the results were not statistically significant. Similarly, there was no significant difference in the decline of ESR within 8 h at 4 °C. However, ESR results decreased significantly after the samples were stored at room temperature for more than 6 h or at 4 °C for more than 8 h. ESR reduction was lower in the samples stored at 4 °C than in those stored at room temperature over the same time period.ConclusionBlood sample storage temperature and duration can affect the measurement of ESR using the Weiss method. ESR testing should be completed within 4 h of sample collection in clinical work.

Novel electron microscopic staining method using traditional dye, hematoxylin

Uranyl acetate (UA) has been routinely used as a staining solution for ultrathin sections used in biological electron microscopy. As a radioactive nuclear material, UA is subject to strict international regulations. To develop an alternative and easy-to-use staining method for ultrathin sections, we examined various commercial light microscopic dyes. We found that Mayer’s hematoxylin followed by Reynold’s lead citrate solution showed staining results comparable to UA and Reynold’s lead citrate solution, and this method is therefore suggested as a reliable and promising alternative to UA staining.

Optimization of laser deposited silver nanoparticle substrates for surface-enhanced raman spectroscopy

Creating sensitive and reproducible substrates for surface-enhanced Raman spectroscopy (SERS) has been a challenge in recent years. While SERS offers significant benefits over traditional Raman spectroscopy, certain hindrances have limited their commercial use, especially in settings where low limits of detection are necessary. We studied a variety of laser-deposited silver microstructured SERS substrates with different morphology as a means to optimize analyte detection. We found that using a 405 nm laser to deposit lines of silver nanoparticles (AgNPS) from a 2 mM silver nitrate and sodium citrate solution offered not only the best enhancement, but also the most consistent and reproducible substrates. We also found that the probability of deposition by laser was wavelength dependent and that longer wavelengths were less likely to deposit than shorter wavelengths. This work offers a better understanding of the laser deposition process as well as how substrate shape and structure effect SERS signals.

Second-Line Drug Susceptibility Testing of Mycobacterium tuberculosis Isolates from Patients in Bayelsa State, Nigeria

Aim: To determine the second-line drug susceptibility testing of Mycobacterium tuberculosis isolates from patients in Bayelsa State, Nigeria.&#x0D; Study Design: A cross sectional study was carried out in this research.&#x0D; Place and Duration of Study: Directly Observed Treatment Short-course (DOTS) Centers across Bayelsa State, between March 2020 and November 2021.&#x0D; Methodology: Ethical approval was obtained from Bayelsa State Ministry of Health, Yenagoa, Nigeria. Informations such as age, sex and residential address was obtained with the help of a questionnaire. A total of 100 sputum sample was collected from 100 patients across all the Local Government Areas. Sputum sample decontamination and homogenization was done using the Sodium Hydroxide/N- Acetyl -L- Cysteine Citrate Solution. Sputum samples were cultured on solid Lowenstein Jensen (LJ) Media. All growths on LJ media were confirmed with Ziehl Neelsen staining and Standard Bioline antigen test. Drug susceptibility test was carried out after bacterial DNA was extracted and amplified using Line Probe Assay (MTBDRplus assay ver 2).&#x0D; Results: Out of 100 patients, 15 had confirmed growth of Mycobacterium tuberculosis. All isolate had no form of mutation on gyr gene, meaning 100% of isolates were susceptibility to flouroquinolones. There were also no mutation detected on rrs gene therefore all strains are also susceptible to Kanamycin, Amikasin and capreomycin. Out of the 15 isolates 14 had no mutation on the eis gene while 1% had mutation of WT2 and MUT1.&#x0D; Conclusion: A good percentage of the isolates are susceptible to second line drugs, therefore cases of extensive drug resistance is not common in Bayelsa State, Nigeria.

Studies on Interionic Interactions of Anti-Tuberculosis Drugs Isoniazid with Mixed Solvents at Different Temperatures: Ultrasonic Studies

Density, ρ, and ultrasonic velocity, u of an anti-tuberculosis drug, isoniazid, INH in the aqueous solutions of potassium citrate, K3Cit, and sodium citrate, Na3Cit were determined at T= (298.15 to 318.15) K and, p =0.1MPa atmospheric pressure. The thermo-acoustic properties like isothermal compressibility (βT), heat capacity ratio (g), molar compression (W), acoustic impedance (Z), molar sound velocity(R), relative association (RA), intermolecular free length (Lf), relaxation time, coefficient of thermal expansion(α), and non-linearity parameters have been evaluated from ultrasonic velocity, u, and density, ρ at the studied temperature T= (298.15 to 318.15) K. The results obtained by these processes have been used to analyze the presence of intermolecular interactions existing in the solutions system (INH+Water+K3Cit/Na3Cit). The concentration and temperature effect of the solutions on intermolecular forces were studied at the same pressure

Application of Thermo Acoustical Parameters for the Evaluation of the Available Volume of Ionic Liquid, 1-Butyl-3-Methylimidazolium Chloride in Mixed Solvents at Different Temperatures

The available volume of 1-Butyl-3-methyl imidazolium chloride, [bmim][Cl] in pure water and aqueous solutions of potassium citrate and sodium citrate at different concentrations of solute and T = (298.15 to 318.15) K have been evaluated by making use of ultrasonic velocity and thermo acoustic parameters followed by a comparative study. The thermo acoustic parameters have been used to determine available volume, V a for the solutions under analysis. For well understanding, the values of found from the thermo acoustic methods were tallied with the values found from the well-defined ultrasonic method (Schaaff’s method). The decrease of the available volume with an increase of the mass fraction of ionic liquid and temperature shows the existence of ion-solvent interactions of IL in the studied solutions. To the best of our knowledge, this study is a pioneering effort in the evaluation of available volume present in the investigated solutions by making use of the ultrasonic approach.

A Comparison of the Commonly Used Surrogate Markers for Citrate Accumulation and Toxicity during Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation

Introduction: Continuous renal replacement therapy using regional citrate anticoagulation is commonly used as a modality of organ support in the critically ill population. Currently, citrate accumulation or toxicity is assessed using surrogate markers, notably the uncorrected total-to-ionized calcium ration. The accuracy and utility of this method have been questioned. Objectives/Aims: The aim of this study was to compare the surrogate markers used for assessing citrate accumulation or toxicity using the measurement of plasma citrate as the gold standard. Methods: Blood was sampled from 20 patients before, during, and after episodes of filtration with citrate concentration measured using spectrophotometry. Demographic and other clinical and biochemical data were also collected. According to protocol, a 15 mmol/L solution of trisodium citrate was used as the prefilter anticoagulant. Results were analyzed using STATA (v16.0) and presented as mean (SD), median (IQR), or simple proportion. Univariate linear regression using citrate concentration as the dependent variable was performed with all surrogate markers. Results: Twenty patients (17 males) were enrolled in the study with a mean (SD) age of 62.7 (9.9) years. The uncorrected calcium ratio had the best fit to the citrate data with an R2 value of 0.39. The albumin-corrected calcium ratio, pH, anion gap (AG), albumin-corrected AG, standard base excess, and strong ion gap all had R2 values less than 0.05. Conclusion(s): In the absence of direct measurement of citrate concentration, uncorrected total-to-ionized calcium ratio is superior to other surrogate markers, though not ideal, in assessing citrate accumulation or toxicity.

Organic anions facilitate the mobilization of soil organic phosphorus and its subsequent lability to phosphatases

PurposeOrganic anions commonly released from plant roots and microorganisms are widely reported to mobilize soil phosphorus (P). We characterized soil organic P that was mobilized by organic anions and assessed its amenability to hydrolysis by phosphatase enzymes.MethodsSix soils differing in organic P concentration were extracted with citrate, malate or oxalate solutions and incubated with preparations of phosphomonoesterase, phosphodiesterase, or phytase. Organic P compounds present in these extracts were putatively identified and quantified with solution 31P-NMR spectroscopy and the enzyme-labile P fractions were assessed by changes in molybdate-reactive P (MRP) concentration.ResultsOrganic P mobilization varied markedly among the organic anions. Extraction with 10 mM citrate was most effective and extracted 7.8-fold more total P than the water controls across all soils. Approximately 95% of the extracted P was non-MRP. The organic anions increased both the amount of P extracted and the proportion of the total extracted P that was phosphatase-labile. Phytase was generally the most effective enzyme with up to 60% of the total non-MRP being amenable to hydrolysis by phytase across all extracts. The presence of inositol hexakisphosphates in the extracts, as well as other forms of organic P including nucleic acids and phospholipids, was verified by 31P-NMR with concentrations dependent on both organic anions and soil type.ConclusionThe combination of organic anions and phosphatases represents a key mechanism by which plants and microorganisms can enhance the bioavailability of soil P. This has important implications for understanding P dynamics in natural and managed ecosystems and for ongoing efforts to improve the P-acquisition efficiency of agricultural plants.