EDTA Research Articles

Single Source Precursor for PAD-LaMnO3 Thin Films

A new lanthanum and manganese ethylenediaminetetraacetate (EDTA) coordination polymer (EDTA4− = [(CH2N)2(CH2-COOH)(CH2COO)4]) was synthesized from La(NO3)3 and Mn(NO3)2 reagents, ethylenediaminetetraacetic acid, and water at room temperature. The structure of the new compound formed, [{La2Mn3(EDTA)3(H2O)11}·12H2O]n, was determined by the single crystal X-ray diffraction technique. The synthesis and characterization of the La(III) and Mn(II) coordination complex, characterized by FTIR spectroscopy, thermogravimetry, and differential thermal analysis of the complex, are envisaged. X-ray crystal structure determination indicates that seven- and four-coordinate modes between La(III)/Mn(Π) and H4EDTA exist. [{La2Mn3(EDTA)3(H2O)11}·12H2O]n crystallizes in the monoclinic space group C2 with unit cell parameters of a = 16.1227(17) Å, b = 14.8049(16) Å, c = 14.8736(16) Å, and β = 116.107(2)°. Using this precursor, LaMnO3 (LMO) epitaxial thin films were grown by the polymer-assisted deposition (PAD) method on (100)SrTiO3 (STO) single crystalline substrates at a temperature of 900 °C. The LMO crystallized films exhibit a (001)LMO/(001)STO out-of-plane epitaxial relationship and a smooth surface morphology.

Complexation Modulated Iron Redox Systems for Waste Water Treatment: A Natural Attenuation Model

AbstractNatural attenuation mimics nature's own cleansing mechanism and offers an effective solution for contaminant treatment under prevalent environmental conditions without generating secondary toxins. Despite obvious advantages, these processes are restricted by a narrow range of reduction potential available within natural water systems. Complexation reaction offers to modulate the redox potential range of transition metals allowing detoxification of persistent contaminants. Consequently, present work describes complexation modulated redox potential of iron systems with environmentally available ligands for degradation of contaminants (textile dyes, antibiotics and toxic metal ions) for a possible application in water treatment under natural attenuation concept. The observed spectrophotometric results are indicative of a significant ligand effect on degradation kinetics of studied contaminants by iron(II) complexes. The kinetic efficacies of iron(II) complexes for contaminant degradation were in the order: aqua<acetate<oxalate<NTA (nitrilotriacetate)<IDA (iminodiacetate)<EDTA (ethylenediamine tetraacetate). This observed reactivity order of iron(II)complexes corroborates well with their oxidation propensity under the given ligand field (E°=+0.131 to+0.771 V in case of EDTA and aqua ligand respectively). The influence of reaction conditions, nature of contaminant and identification of electroactive species was investigated by using spectro‐electrochemical experiments with selected systems. Two plausible mechanisms of contaminant degradation were proposed:(i)direct reduction of contaminants by iron(II) complexes(ii) and indirect degradation through reaction between iron(II) complexes and dissolved oxygen to produce reactive oxygen species. This modular study besides being an insight in environmental redox processes is also aimed for the impetus towards natural attenuation based treatments for degradation of contaminants, especially under aerobic conditions that are rich in both iron(II) and organic matter.

Assessment of Real-Time Operative Torque during Nickel–Titanium Instrumentation with Different Lubricants

The aim of the present study is twofold: to assess ex vivo the role of different lubricants on real-time torque generated during intracanal instrumentation and to check whether two different kinds of torque parameters, operative torque (OT) and average peak torque (APT), could produce similar results. Forty extracted single-rooted teeth were selected for the present study and divided into four equal groups (n = 10): Group A, NaCl 0.2%; Group B, NaOCl 5%; Group C, ethylenediaminetetraacetate (EDTA), and Group D, EDTA and hydrogen peroxide. Afterwards, Edge Taper F2 (Edge Endo, Albuquerque, New Mexico) were rotated clockwise at 300 rpm with 3 Ncm maximum torque by an endodontic torque recording motor. In each sample, mean OT and mean APT were recorded and statistically analyzed with one-way ANOVA and a post hoc Bonferroni between groups (p < 0.05). EDTA (12.11 ± 4.45 Ncm) showed statistically significant (p < 0.05) lower values compared with the other tested irrigant for both parameters. Overall, the two different parameters were both able to differentiate between the influence of lubricants on torsional loads.

Effects of nitrogen, phosphorus, EDTA and sodium chloride on biomass and lipid accumulation of Chaetomorpha aerea

The increase of total lipid and fatty acids production was studied under different nutrient stress conditions using the macroalga, Chaetomorpha aerea. The effects of nitrogen, phosphorus, ethylene diamine tetra-acetate and sodium chloride on the growth and lipid accumulation were systematically investigated in laboratory conditions. The biomass was harvested at different stages of cultivation and assessed. The maximum changes of growth and lipid accumulation were observed in the exponential phase at different cultural conditions. The two-fold increase of total lipid was found in the order of 28.27±0.04 % (at 0.1 g/L nitrogen) > 27.30±0.37 % (at 0.5 g/L of phosphorus) > 25.86±0.77 % (at 0.05 g/L of EDTA)> 24.37±0.04 % (at 0.05 g/L NaCl) on 8th day of cultivation. The fatty acids were identified and quantified by gas chromatography mass spectrometry (GC-MS). The alga produces significantly high amount of monounsaturated fatty acid (MUFA) and saturated fatty acids (SFA) than the polyunsaturated fatty acids (PUFA) in different cultural conditions. The elevated levels of C16:1, C18:1 and C20:1 was identified under nitrate, phosphate and salt stress conditions, which are more suitable for biodiesel production.

Prefilled Cyclic Olefin Sterilized Syringes of Norepinephrine Injection Solution Do Not Need to Be Stabilized by Antioxidants

Norepinephrine is a potent α-sympathomimetic drug which plays an important role in the acute treatment of hypotension and shock. Commercially available norepinephrine solutions contain sodium metabisulfite (Na2S2O5) as an antioxidant. However, prefilled cyclic olefin polymer syringes are not compatible with sodium metabisulfite. The aim of this study was to develop a new formulation of 0.1-mg/mL norepinephrine solution without sodium metabisulfite which is chemically stable and sterile and can be stored in prefilled polymer syringes. Formulation studies were performed with 0.1-mg/mL norepinephrine solution with 0, 0.05, or 0.1% ascorbic acid added as antioxidant. The syringes were filled under nitrogen gassing, stored at 20 ± 5°C, and protected from daylight. Based on the formulation test results, the final formulation was defined and stability testing at 20 ± 5°C was performed measuring norepinephrine concentration, pH, clarity, color of the solution, subvisible particles, and sterility at time intervals up to 12 months. The norepinephrine concentrations at t = 22 weeks were 100.4%, 95.4%, and 92.2% for the formulations with no ascorbic acid and with 0.05% and 0.10% ascorbic acid, respectively. Three batches for the stability study were produced containing norepinephrine, sodium edetate, sodium chloride, and water for injections filled under nitrogen gassing and stored at 20 ± 5°C. Norepinephrine concentrations were respectively 98.8%, 98.6%, and 99.3% for batches 1, 2, and 3 at t = 12 months. It can be concluded that norepinephrine (0.1 mg/mL) solution without metabisulfite is stable for at least 12 months at room temperature when protected from daylight.

Rapid synthesis of chitosan-capped gold nanoparticles for analytical application and facile recovery of gold from laboratory waste

Chitosan-capped gold nanoparticles (CS-AuNPs) were synthesized via a rapid method by exposing 0.75 mL of 10 mM HAuCl4 and 5 mL of 0.1% w/v chitosan solution to microwave irradiation at 125 °C for 40 s. The resulting red colloidal solution contained monodispersed, spherical, and stable CS-AuNPs with a mean diameter of 17.8 nm and showed the maximum absorption peak at 520 nm. Owing to the positively charged surface, CS-AuNPs were applied to the assay of the polyanionic compound disodium edetate based on the aggregation-induced red-to-blue color change of the particles and the measurement of increased absorbance at 670 nm. The assay was accurate and precise; its results were comparable to those obtained from the titrimetric reference method. Moreover, gold was shown to be easily recovered from CS-AuNPs through alkaline-induced precipitation followed by acid treatment and heating, which provides a facile and efficient means for treatment of laboratory waste.

Condensation Product of p-anisaldehyde and L-phenylalanine: Fluorescent "on-off" Sensor for Cu2+ and IMPLICATION Logic Gate.

(Z)-2-(4-methoxybenzylideneamino)-3-phenylpropanoic acid (L) synthesized by condensation of p-anisaldehyde and L-phenylalanine acts as selective fluorescent as well as voltammetric sensor for Cu2+ in 2:1 (v/v) CH3OH:H2O. The fluorescence intensity of L (λmax 425nm) is quenched ca. 65% by Cu2+. Metal ions - Li+, Na+, K+, Al3+, Cu2+, Zn2+, Cd2+, Hg2+, Mn2+, Ni2+ and Pb2+ do not interfere. The binding constant and the detection limits were calculated to be 0.56 × 102M-1 and 10-6M respectively. DFT and TDDFT calculations confirmed 2:1 binding stoichiometry between L and Cu2+ obtained from fluorescence data. The interaction between L and Cu2+ is reversible for many cycles with respect to ethylenediamine tetraacetate anion (EDTA2-) which results in IMPLICATION logic gate.

Removal of heavy metals in medical waste incineration fly ash by Na2EDTA combined with zero-valent iron and recycle of Na2EDTA: Acolumnar experiment study

ABSTRACT In this study, an effective circulating system was developed to remove heavy metals in medical waste incineration (MWI) fly ash. MWI fly ash (MWIFA)-column experiments were performed to remove Cu, Pb, Zn, Cd, and Ni from MWIFA using EDTA disodium (Na2EDTA). Iron-column experiments were conducted to study the removal effect of zero-valent iron on the five heavy metals from washing wastewater. Toxicity Characteristic Leaching Procedure (TCLP) test method was employed to evaluate heavy metals toxicity of MWIFA residues generated after 0–0.2 mol/L Na2EDTA solution treated. After being washed by 0.2 mol/L Na2EDTA solution, TCLP leaching values of Cu, Pb, Zn, Cd, and Ni were the lowest and satisfied the standard (GB 5085.3–2007), and the leaching values were 58.4 ± 2.0 mg/L, 2.81 ± 0.14 mg/L, 64.3 ± 4.0 mg/L, 0.156 ± 0.005 mg/L, 0.381 ± 0.006 mg/L. Concentrations of Cu, Pb, Zn, Cd, and Ni in iron-column effluent were reduced by 99.7%, 91.6%, 91.6%, 75.4%, and 75.7%, respectively. Na2EDTA was recovered and recycled to the removal of heavy metals from MWIFA. Comparing new Na2EDTA solution with recycled Na2EDTA solution, recycled Na2EDTA and water could be reutilized to dispose MWIFA. The removal efficiencies of Cu, Pb, Zn, Cd, and Ni by recycled 0.2 mol/L Na2EDTA solution were 67.1%, 68.8%, 63.2%, 73.9%, 50.7%, respectively, the removal efficiencies using recovered Na2EDTA decreased by 2.6%, 3.9%, 3.3%, 4.2%, and 1.6%, respectively. Successive batch experiments were also conducted to evaluate industrialization potential and reusable times for recycled Na2EDTA. After four recirculation cycles, extraction efficiencies of Pb and Cd (removal efficiency at different cycles divided by removal efficiency of new Na2EDTA) declined toward 80%. Results from this research indicated that this circulating system possessed industrialization potential. Implications: An effective circulating system was developed to remove heavy metals in MWI fly ash (MWIFA). Integration of Na2EDTA with Fe0 promoted the removal of heavy metals from MWIFA. Na2EDTA, NaCl and water were stepwise extracted from iron-column effluent, respectively. Recovered Na2EDTA can still effectively remove heavy metals from MWIFA. Results from this research indicated that this circulating system possessed industrialization potential.

Further studies of photodegradation and photocatalytic hydrogen production over Nafion-coated Pt/P25 sensitized by rhodamine B

TiO2 is an excellent photocatalyst in photodegradation and hydrogen production. Herein, through simple modification of Pt/TiO2 (P25) by Nafion (Nf), photocatalyst Nf/Pt/P25 was prepared and characterized. Photodegradation of rhodamine B (RhB) and photocatalytic hydrogen production over the Nf/Pt/P25 were investigated and compared with those of Nf/P25, P25 and Pt/P25. The results showed the Nf coating caused remarkable improvements in RhB degradation and hydrogen production with RhB as sensitizer. Especially, for the first time, the influence of sacrificial reagent (SR) on hydrogen production performance was studied in detail and the results indicated replacing disodium ethylene-diamine tetraacetate (EDTA) used in literature with triethanolamine (TEOA) leads to a significant enhancement in activity. The H2-evolving rate of RhB-Nf/Pt/P25-TEOA system is up to 12 times that of RhB-Nf/Pt/P25-EDTA. Besides, other H2 evolution parameters were optimized and cycling H2 evolution tests over the Nf/Pt/P25 were conducted. The results confirmed that concurrent H2 evolution and RhB degradation can be achieved even with very few RhB. Finally, reasons for the enhanced H2 production performance were proposed. It addressed the importance of selecting a suitable SR and will be very helpful for further work on photocatalytic hydrogen production and photodegradation.

Low-carbon hydrocarbon fracturing fluid with fast cross-linking rate based on n-hexane/n-octane: synthesis and properties

ABSTRACT The use of slick-water fracturing fluids has been greatly limited owing to the shortage of water and transportation difficulties in some areas. Serious formation damage occurred in the shale gas reservoirs with low porosity and permeability during the slick-water fracturing with large amounts of water. A fast cross-linking waterless fracturing fluid using the n-hexane/n-octane low-carbon hydrocarbons was prepared in this work. Firstly, a polyphosphate intermediate was synthesized by triethyl phosphate reacting with phosphorus pentoxide, which then reacted with a mixed alcohol of n-butanol, n-octanol, and dodecanol to get the dialkyl phosphate (named as gelling agent). Ferric sulfate, ethylene glycol, sodium citrate, sodium edetate were used to prepare a composite iron-based cross linker with an excellent gelation time and gelation performance, which was composed of 30% ferric sulfate, 10% glycol, 11% trisodium citrate, 9% sodium edetate, and 30% deionized water. By optimizing the ratio of gelling agent to cross linker and the content of gelling agent, an anhydrous fracturing fluid formulation based on n-hexane/n-octane was prepared: n-hexane/n-octyl (mass percent 100%) + gelling agent (1.6%-1.8%)+cross linker (0.6%-0.8%) + gel breaker (0.6%-1.0%).The n-hexane and n-octane fracturing fluids can be used in the formation temperature of 60°C, and 100°C, and the viscosity for the fracturing fluid was 178 and 230 mPa.s under the shear rate of 170 s−1 and shear time for 90 min. The sedimentation velocity of a single ceramsite was 0.2780 cm/min, and the sedimentation velocity of the mixed ceramsite was 0.0022 cm/min, which fully satisfied the fracturing suspension performance. The crushing time of n-hexane and n-octane fracturing fluid was controllable (5–10 h), and the gel breaking effect was excellent (less than 2 mpa.s).

Estimation of total phenolic content and Studies on antioxidant activity of different extracts of Cadaba farinose Forsk by hydroxy radical and iron chelating techniques

Cadaba farinosa (family Capparidaceae) is generally known as “Indian cadaba” in the traditional ayurvedic system. The current study, aerial parts of different concentrates (Pet.ether, ethyl acetate and methanol) of Cadaba farinose was evaluated for its in-vitro antioxidant potential by hydroxy radical taking ascorbate as a standard. The iron-chelating activity is taking Ethylenediamine tetraacetate as standard and estimation of total phenol content as equivalent to mg/g of Gallic acid. The methanolic concentrates of Cadaba farinose & ascorbic acid exhibited antioxidant potential possessing IC50 205µg/ml & 65µg/ml (Hydroxy radical) , methanolic concentrates of Cadaba farinose & Ethylenediamine tetraacetate exhibited antioxidant potential possessing IC50 240µg/ml & 70µg/ml (iron-chelating activity). The methanolic and EA concentrates of Cadaba farinose contain total phenolic content 9.86 ± 0.62 and 3.98 ± 0.54, respectively. The IC50 value was originated that methanolic concentrates of Cadaba farinose more efficient in hydroxy radical, iron chelating activity compared EA & PE concentrates. The methanolic extract of Cadaba farinose having more free radical activity due to the presence of phenolic content as a bioactive compound. This result indicates that aerial parts of methanolic concentrate Cadaba farinose could serve as a natural antioxidant, which may be useful in preventing free radical-induced diseases.

Partial purification and characterisation of α-amylases from the digestive tract of the Indian major carp Labeo rohita (Hamilton, 1822)

Partial purification of α-amylases from the digestive tract of the Indian major carp Labeo rohita (Hamilton, 1822) through acetone fractionation and ion exchange chromatography (DEAE-SephadexA-50) resulted in 8-fold purification with 86% recovery. Characterisation of amylase activity revealed two pH optima at 4.5 and 6.5. Activity was stable over wide pH ranges of 3.5 to 4.5 and 7 to 12. Optimum incubation temperature was 35°C. The enzyme lost 91% activity at 60°C within 15 min and was inhibited by Amylase inhibitor Type-1 (wheat); 1, 10 Phenanthroline, Ethylene diamine tetra-acetate (EDTA) and Phenyl methyl sulphonyl fluoride (PMSF). Heavy metal ions Hg++ and Cu++ strongly inhibited the enzyme activity, while Zn++ and Bi++ inhibited to a lesser extent. Native polyacrylamide gel electrophoresis of the purified amylase fractions revealed four bands, with corresponding molecular weights of 43.59, 52.36, 55.42 and 54.01 kDa. α-Amylase activity from L. rohita exhibited linear hydrolysis of starch upto 7% concentration in 60 min.

Chemical profile, antiproliferative, antioxidant and enzyme inhibition activities of Ocimum basilicum L. and Pulicaria undulata (L.) C.A. Mey. grown in Sudan

In the present study, essential oils extracted from the leafy stems of Ocimum basilicum (Family Lamiaceae) and Pulicaria undulata (Family Asteraceae) were investigated for their chemical profiles and biological activity including antioxidant, antiproliferative and enzyme inhibition activities. The chemical composition of essential oil was determined using Gas Chromatography-Mass Spectrometry. The antioxidant capacity was tested by scavenging of free radicals, reduction potential, chelating ability on ferrous ions and phosphomolybdenum assays. Cell viability was evaluated on human breast carcinoma (MCF7) and human colon adenocarcinoma (HT29 and HCT116) cell lines. Enzymatic activity was evaluated against α-glucosidase, α-amylase, acetylcholinesterase, butyrylcholinesterase, and tyrosinase. Based on the results obtained, in silico studies was performed to identify potential inhibitor of tyrosinase activity. Results showed that oil of O. basilicum was predominantly composed of methyl chavicol (51.9%) followed by linalool (20.0%). Oil of P. undulata was represented by oxygenated monoterpenes (96.9%) with carvotanacetone (92.1%) as the main molecule. Both oils exerted antioxidant activities with oil from P. undulata exerted significant (p<0.05) higher scavenging activity (20.92±0.05DPPH and 62.36±0.25ABTS mg trolox equivalents (TEs)/g) while that obtained from O. basillicum showed significant (p<0.05) higher total antioxidant activity (16.72±0.95 mmol TEs/g), ion reducing power (86.30±2.80FRAP and 115.31±2.03CUPRAC mg TEs/g) and metal chelating ability (21.08±3.45 mg disodium edetate equivalents /g). Both oils showed considerable tyrosinase and α-amylase inhibition activity while only oil of P. undulata displayed acetylcholinesterase (0.95 ± 0.06 mg galanthamine equivalents (GALAEs)/g), butyrylcholinesterase (1.19 ± 0.13 mg GALAEs/g) and α-glucosidase (32.59 ± 0.20 mg acarbose equivalents (ACAEs)/g) inhibition capacity. Both oils showed good anti-proliferative activity towards the three cell lines with higher activity observed from that of O. basillicum (2.8–3.3 µg/mL). In silico studies suggested that methyl chavicol represent a potential inhibitor of tyrosinase activity. In conclusion, the two oils show promise as natural agents with functional properties for food, cosmetics, and pharmaceutical industries.

Probing the Structure and Binding Mode of EDTA on the Surface of Mn3O4 Nanoparticles for Water Oxidation by Advanced Electron Paramagnetic Resonance Spectroscopy.

Identification of the surface structure of nanoparticles is important for understanding the catalytic mechanism and improving the properties of the particles. Here, we provide a detailed description of the coordination modes of ethylenediaminetetraacetate (EDTA) on Mn3O4 nanoparticles at the atomic level, as obtained by advanced electron paramagnetic resonance (EPR) spectroscopy. Binding of EDTA to Mn3O4 leads to dramatic changes in the EPR spectrum, with a 5-fold increase in the axial zero-field splitting parameter of Mn(II). This indicates significant changes in the coordination environment of the Mn(II) site; hence, the binding of EDTA causes a profound change in the electronic structure of the manganese site. Furthermore, the electron spin echo envelope modulation results reveal that two 14N atoms of EDTA are directly coordinated to the Mn site and a water molecule is coordinated to the surface of the nanoparticles. An Fourier transform infrared spectroscopy study shows that the Ca(II) ion is coordinated to the carboxylic ligands via the pseudobridging mode. The EPR spectroscopic results provide an atomic picture of surface-modified Mn3O4 nanoparticles for the first time. These results can enhance our understanding of the rational design of catalysts, for example, for the water oxidation reaction.

Facile fabrication of mpg-C3N4/Ag/ZnO nanowires/Zn photocatalyst plates for photodegradation of dye pollutant

In the present study, mpg-C3N4/Ag/ZnO NWs/Zn photocatalyst plates were fabricated through facile dip-coating process of silver (Ag) and mesoporous graphitic carbon nitride (mpg-C3N4) onto zinc oxide nanowires (ZnO NWs) previously formed by electrochemical anodizing of Zn plates. The structure, optical and electrochemical characterizations of the fabricated samples were investigated by XRD, FESEM, EDX, TEM, FTIR, BET, PL, UV–vis DRS, and EIS analyses. To evaluate the photocatalytic activity of the plates, the main key factors such as number of photocatalyst plates, dye concentration, initial pH, and reaction time for the degradation of Direct Orange 26 (DO26) dye under ultraviolet (UV) light illumination were studied. The best photocatalytic efficiency of 94 % was achieved using four photocatalyst plates, 10 mg/L DO26, and pH = 6 in 120 min of reaction time. The integration of the mpg-C3N4/Ag/ZnO NWs/Zn plates, adsorption, and photolysis inferred the existence of a synergy index of 5 for the degradation of target pollutant. In the presence of edetate disodium (EDTA-2Na) and ethanol (EtOH), degradation efficiency of DO26 was remarkably dropped to 43.6 % and 19.3 % by the photocatalytic process respectively, indicating the major role of h+ and OH in the destruction of target molecules. The overwhelming photocatalytic mechanism of the photocatalyst was further clarified for the elimination of DO26. The fabricated photocatalyst demonstrated remarkable stability and recyclability for four consecutive catalytic cycles. Fabrication of the mpg-C3N4/Ag/ZnO NWs/Zn plates is anticipated to be a rational design for photocatalytic degradation of various pollutants.

P0656FULL AGE SPECTRUM EQUATION IN THE ESTIMATION OF GLOMERULAR FILTRATION RATE IN RUSSIAN ADULT PATIENTS WITH CHRONIC KIDNEY DISEASE

Abstract Background and Aims Glomerular filtration rate (GFR) is the most important and accurate parameter of kidney function in the course of chronic kidney disease (CKD). Renal or plasma inulin, diethylenetriaminepentaacetate (DTPA), ethylenediaminetetraacetate (EDTA), radiocontrast agents (iohexol, iothalamate) and some other substances clearances are the reference methods for determining GFR. However, these methods cannot be applied routinely because of the inconvenience. Several available methods have been developed to estimate GFR in a simpler manner and at low costs. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is widely used to evaluate the GFR in practice. However, this equation is not accurate for the full age spectrum. In 2016, the new equation, full age spectrum equation, based on the serum creatinine (FAScr), was developed and can be applicable to all ages. However, data on the benefits of using the FAScr-method in different populations are contradictory. In particular, it is unclear whether the FAScr provides any advantages over the CKD-EPI method in adults. In this regards, we attempted to compare data obtained FAScr method with results some non-reference and reference methods in adult Russian population. Method We examined 120 Caucasian patients (M:F - 52:68; age 18-76 year) with CKD 1 - 5 stages. Patients with nephrotic syndrome and congestive heart failure were excluded. GFR (reference method) measured by plasma clearance of 99mTc-DTPA (CDTPA). CDTPA determined by one- compartment model 2-4 h method using a Chantler-Barratt linear correction. Estimation GFRs (eGFR) were established by Cockcroft-Gault creatinine clearance (CG), CKD-EPI (creatinine), FAScr and Modification of Diet in Renal Disease (MDRD) methods. Also, renal creatinine clearance (Ccr; UV/P method) was measured. Only GFRs values corrected on 1.73 m2 body surface area had been use. Results The values of GFR (Mean(SEM)) are: CDTPA 67.0(2.46); FAS 69.7(2.50); CKD-EPI 64.3(2.54); MDRD 60.9(2.62); CG 77.6(3.31); Ccr 85.2(3.40), мл/мин/1.73 m2. MDRD was significantly lower (paired Student t-test with correction on multiply comparison by Benjamini-Hochberg method) than CDTPA (P=0.0024), CG (P=0.0001) or Ccr (P&amp;lt;0.0001) were significantly higher. The bias (CDTPA minus non reference GFR) were: FAS -2.67(1.71); CKD-EPI 2.72(1.58); MDRD 6.12(1.78); CG -10.57(2.51); Ccr -18.22(2.26), ml/min. All biases are significantly differ between themselves (P from 0.00064 to &amp;lt;0.000001). The percentage of P30 of the FAS 81.6(3.5) was not significant differ from P30 of CKD-EPI (78.3(3.8); P=0.524) or MDRD (71.7(4.1); P=0.071). However, P30 of CG (67.5(4.3),%; P=0.01) or Ccr (54.2(5.42),%; P&amp;lt;0,001) were significant lower, than P30 of FAS. There were significant comparable direct correlations between CDTPA and FAS (r=0.764), CKD-EPI (r=0.801), MDRD (r=0.756), CG (r=0.656), Ccr (r=0.749); P&amp;lt;0.00001 in all cases. Conclusion In adult Russian population FAScr-method of GFR estimation had not any advantage over CKD-EPIcr-method.

Corrosion protection properties of anodized AA2024T3 alloy sealing with organic-based species

The present study investigates the effect of EDTA disodium salt and Monosodium citrate treatments to improve the corrosion resistance of anodized aluminum alloys coated with sol–gel. The anticorrosive properties were studied by Electrochemical Impedance Spectroscopy (EIS) technique. The chemical and morphological characterization were carried out by Focus Ion Beam (FIB), Field Emission Scanning Microscopy (FESEM) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The results suggests that the addition of any of these salts in the sol–gel film improves the corrosion resistance of the anodized aluminum alloy. Very stable and high impedance values are obtained after a long period of immersion in 0.1 M NaCl solution. The best results are obtained with the addition of 0.5 g L−1 EDTA disodium salt and 1 g L−1 monosodium citrate. The improvement of the corrosion properties is attributed to the changes in sol–gel formation that produce a more compact protective barrier with the COO− groups, which can prevent the entry of aggressive electrolyte by repulsion of charges.

The Structural Basis of the Binding of Various Aminopolycarboxylates by the Periplasmic EDTA-Binding Protein EppA from Chelativorans sp. BNC1.

The widespread use of synthetic aminopolycarboxylates, such as ethylenediaminetetraacetate (EDTA), as chelating agents has led to their contamination in the environment as stable metal–chelate complexes. Microorganisms can transport free EDTA, but not metal–EDTA complexes, into cells for metabolism. An ABC-type transporter for free EDTA uptake in Chelativorans sp. BNC1 was investigated to understand the mechanism of the ligand selectivity. We solved the X-ray crystal structure of the periplasmic EDTA-binding protein (EppA) and analyzed its structure–function relations through isothermal titration calorimetry, site-directed mutagenesis, molecular docking, and quantum chemical analysis. EppA had high affinities for EDTA and other aminopolycarboxylates, which agrees with structural analysis, showing that its binding pocket could accommodate free aminopolycarboxylates. Further, key amino acid residues involved in the binding were identified. Our results suggest that EppA is a general binding protein for the uptake of free aminopolycarboxylates. This finding suggests that bacterial cells import free aminopolycarboxylates, explaining why stable metal–chelate complexes are resistant to degradation, as they are not transported into the cells for degradation.

Possible differential benefits of edetate disodium in post-myocardial infarction patients with diabetes treated with different hypoglycemic strategies in the Trial to Assess Chelation Therapy (TACT)

BackgroundThe NIH-funded Trial to Assess Chelation Therapy (TACT) randomized 1708 stable patients age ≥50 who were ≥6 months post myocardial infarction to 40 infusions of an edetate disodium-based regimen or placebo. In 633 patients with diabetes, edetate disodium significantly reduced the primary composite endpoint of mortality, recurrent myocardial infarction, stroke, coronary revascularization, or hospitalization for angina (hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.44–0.79, p < 0.001). The principal secondary endpoint of a composite of cardiovascular death, myocardial infarction, or stroke was also reduced (HR 0.60, 95% CI 0.39–0.91, p = 0.017). It is unknown if the treatment effect differs by diabetes therapy. MethodsWe grouped the subset of 633 patients with diabetes according to glucose-lowering therapy at time of randomization. The log-rank test was used to compare active therapy versus placebo. All treatment comparisons were performed using 2-sided significance tests at the significance level of 0.05 and were as randomized. Relative risks were expressed as HR with associated 95% CI, calculated using the Cox proportional hazards model. ResultsThere were 162 (25.7%) patients treated with insulin; 301 (47.5%) with oral hypoglycemics only; and 170 (26.8%) receiving no pharmacologic treatment for diabetes. Patients on insulin reached the primary endpoint more frequently than patients on no pharmacologic treatment [61 (38%) vs 49 (29%) (HR 1.56, 95% CI 1.07–2.27, p = 0.022)] or oral hypoglycemics [61 (38%) vs 87 (29%) (HR 1.46, 1.05–2.03, p = 0.024)]. The primary endpoint occurred less frequently with edetate disodium based therapy versus placebo in patients on insulin [19 (26%) vs 42 (48%) (HR 0.42, 95% CI 0.25–0.74, log-rank p = 0.002)], marginally in patients on oral hypoglycemics [38 (25%) vs 49 (34%) (HR 0.66, 95% CI 0.43–1.01, log-rank p = 0.041)], and no significant difference in patients not treated with a pharmacologic therapy [23 (25%) vs 26 (34%) (HR 0.69, 95% CI 0.39–1.20, log-rank p = 0.225)]. The interaction between randomized intravenous treatment and type of diabetes therapy was not statistically significant (p = 0.203). ConclusionsEdetate disodium treatment in stable, post-myocardial infarction patients with diabetes suggests that patients on insulin therapy at baseline may accrue the greatest benefit.Clinical Trial Registration: clinicaltrials.gov identifier: http://clinicaltrials.gov/ct2/show/NCT00044213?term=TACT&rank=7 identifierTrial to Assess Chelation Therapy (TACT), NCT00044213.

Metabolomic Profiling Revealed Potential Biomarkers in Patients With Moyamoya Disease.

Metabolomics is increasingly used to observe metabolic patterns and disease-specific metabolic biomarkers. However, serum metabolite analysis of moyamoya disease (MMD) is rarely reported. We investigated serum metabolites in MMD and compared them with those of healthy controls (HCs) using a non-targeted gas chromatography–mass spectrometry (GC–MS) approach to identify metabolic biomarkers associated with MMD. Forty-one patients with MMD diagnosed by cerebral angiography and 58 HCs were recruited for our study. Comparative analyses (univariate, multivariate, correlation, heatmaps, receiver operating characteristi curves) were performed between MMD patients and HCs. Twenty-five discriminating serum metabolic biomarkers between MMD patients and HCs were identified. Compared with HCs, MMD patients had higher levels of phenol, 2-hydroxybutyric acid, L-isoleucine, L-serine, glycerol, pelargonic acid, L-methionine, myristic acid, pyroglutamic acid, palmitic acid, palmitoleic acid, stearic acid, octadecanamide, monoglyceride (MG) (16:0/0:0/0:0), and MG (0:0/18:0/0:0), and lower levels of L-alanine, L-valine, urea, succinic acid, L-phenylalanine, L-threonine, L-tyrosine, edetic acid, and oleamide. These metabolic biomarkers are involved in several pathways and are closely associated with the metabolism of amino acids, lipids, carbohydrates, and carbohydrate translation. A GC–MS-based metabolomics approach could be useful in the clinical diagnosis of MMD. The identified biomarkers may be helpful to develop an objective diagnostic method for MMD and improve our understanding of MMD pathogenesis.