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The study investigated the effect of hydrodynamic conditions on the formation of enhanced biological phosphorus removal (EBPR) granular sludge without losing the EBPR capacity, and its structure. The effect of hydrodynamic conditions on the formation of EBPR granular sludge was evaluated by using the minimum settling velocity, (Vs)min, and superficial air velocity. The application of (Vs)min strategy was proved to be beneficial in maintaining granular biomass without losing the EBPR capacity. Microscale structure, the chemical composition and chemically stored phosphorus of the matured EBPR granular sludge were determined by using ESEM‐EDX and cold perchloric acid (PCA) analyses. The results of both the ESEM‐EDX and PCA analyses proved that the poly‐P granules were stored extracellular in EPS structure of EBPR granular sludge. Therefore, the EBPR granular sludge has a high potential for both removal and recovery of phosphorus from wastewater, which needs to be investigated in future studies. [ABSTRACT FROM AUTHOR]

Accuracy and repeatability of the results obtained by potentiometric determination mostly depend on the stoichiometric ratio between the quantity of titrant used and the quantity of sample to be examined. During the optimization of the method, care should be taken to adjust the sample amount to provide suitable volume of titrant, in order to avoid the titration error with consumption above 90% of the total burette volume. In this study suitable approach for optimization of method for potentiometric titration of glycine with 0.1 M perchloric acid was demonstrated, followed by evaluation of measurement uncertainty of the results. The results obtained from the method validation study (statistical error as estimate for precision, and proportional systematic error and additional systematic error as estimates of bias) were used for estimation of uncertainty of measurement of the result, using top-down approach. Comparable estimates for combined (0.5%) and expanded uncertainty (1.0%) were also obtained using two different approaches: bottom-up approach and top-down approach using data from participation in proficiency testing studies. [ABSTRACT FROM AUTHOR]

The research focus of this work was development and validation of an efficient analytical method that can be used for separation and determination of related substances of bisoprolol in finished drug product using reversed-phase HPLC with UV-DAD. In a previous systematic study of various stationary phases and elution conditions it was found that several octadecylsilane phases can be successfully employed for separation of the critical pairs of bisoprolol and its related degradation products. Namely, method development led to conclusions that satisfactory resolution and peak shapes were obtained with gradient elution with water with 0.2% perchloric acid and acetonitrile and the reversed-phase columns: Hypersil 3 BDS C18 (100 x 4 mm, 3 µm); Zorbax SB C18 (150 x 4.6 mm, 3.5 µm); Acquity UPLC BEH C18 (50 x 2.1 mm, 1.7 µm), and Xterra MS C18 (100 x 4.6 mm, 3.5 µm). Since regular quality control includes the parameter related substances, which is of great importance for the overall quality of dosage forms, this study was oriented towards widening the available validated analytical methods for determination of this parameter. In this work, the results from the validation of the method for determination of related substances of bisoprolol using Zorbax SB C18 150 x 4.6 mm, 3.5 µm, are presented. Validation parameters that were tested (linearity, accuracy, precision, selectivity) confirmed that the method is suitable for its intendance and it was used for characterization of the samples from a forced degradation study of bisoprolol tablets. [ABSTRACT FROM AUTHOR]

Heavy metals may constitute health hazards even at cellular level, causing oxidative stress, where they generate free radicals that may overwhelm the body's natural antioxidant. The study is aimed at investigating the presence of some heavy metals (Cd, Cr, Pb, Fe and Sb) in 10 samples each of vaginal suppositories and ophthalmic preparations obtained from registered pharmacies in Abraka, Delta State, Nigeria. The samples were obtained, individually opened, carefully and 1 g of each digested using 6 ml of nitric acid (HNO3) and 1 ml of perchloric acid (HQO4) with further digestion using 1.0 ml, 0.1M perchloric acid immediately after heating. Thereafter, the samples were analysed using atomic absorption spectrophotometer (AAS). The results showed that the samples contained trace amounts of heavy metals (Cd, Cr, Pb, Fe). However, antimony was not detected in any of the samples. This study suggests that the heavy metals present in the samples were well within the WHO heavy metal contamination limit value and therefore are of good quality in respect of heavy metal-induced eye damage, eye irritation, vaginal burn sensations, and aggravation of conditions which these pharmaceutical products are meant to treat or manage. [ABSTRACT FROM AUTHOR]

Four zinc metal-organic frameworks (MOFs) with 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide (odabco) as a bridging ligand were synthesized by varying the solvent and the anionic composition of the reaction medium. The synthesis in a mixture of N, N-dimethylacetamide and water acidified with nitric acid affords the compound [Zn2(odabco)3(OAc)2](NO3)2(1) containing coordinated acetate anions. The compound [Zn2(μ-O)(odabco)3](NO3)2 · NMP · 2H2O (2) crystallizes in a mixture of N-methylpyrrolidone (NMP) and water in the presence of triethylamine as the base. The compound [Zn2(odabco)4](NO3)3(ClO4) · 2 DMF (3) was obtained in N,N-dimethylformamide (DMF) acidified with perchloric acid. The synthesis in a mixture of DMF and dioxane (dox) acidified with a larger amount of perchloric acid produces [Zn(odabco)2](NO3)(ClO4) · 0.4 dox (4). The crystal structures of new compounds 2–4 were determined by single-crystal X-ray diffraction. Compound 2 consists of binuclear {Zn2O}2+ units, serving as nodes in the three-dimensional framework with pcu topology and a solvent-accessible volume (Vpore) of 37%. The isomeric metal-organic coordination frameworks of 3 (Vpore = 42%) and 4 (Vpore = 47%) are built from mononuclear units and have a BCT zeolite topology. The optical absorption of compounds 1–4 was characterized by diffuse reflectance spectroscopy. [ABSTRACT FROM AUTHOR]

Isoicotinium dichromate is oxidises hydroxy group into carbonyl group. INDC is derived from pyridine 4-carboxalic acid The kinetic oxidation of menthol Show's first order reaction with respect to oxidant. Substrate and perchloric acid. The reaction rate increases with decreases in the dielectric constant. The consequence of oxidation are the corresponding menthone. The ΔH# and ΔS# were delibrated by Temprature effect. [ABSTRACT FROM AUTHOR]

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A surface‐integrated form of the widely used (anharmonic) Lennard‐Jones 12–6 interaction potential, the Lennard‐Jones 9–3 potential, is used to develop a quadratic activation/driving force relationship that gives rise to asymmetric Tafel plots for electron transfer occurring with simultaneous interaction rupture. The Tafel plots are shown to exhibit linearity over a wide potential range, depending on the ratio of the Gibbs interaction well to the solvent reorganisation free energy. The fit of the model to experimental data for a ferrocene‐based self‐assembled monolayer (SAM) bathed by aqueous perchloric acid suggests ion pairing between ferricenium and perchlorate ions. This crude and primitive model readily enables experimentalists to obtain a parametric understanding of the physicochemical dynamics underpinning interaction rupture in concert with electron transfer, which may empower routes to improve the efficiency of a plethora of topical electrochemical technologies. [ABSTRACT FROM AUTHOR]

A sulfur-containing polymer was prepared by the reaction of granulated polyvinyl chloride with sulfur. Oxidation of this polymer with nitric acid led to the formation of a sulfonic acid cation-exchange resin. The presence of the sulfo group in the resin was proved by IR spectroscopy, and the cation-exchange properties were confirmed by determining the static exchange capacity. The morphology of the cation-exchange resin obtained was examined by scanning electron microscopy. The resin is heat-resistant at 423 K, and its resistance to strong oxidants such as perchloric and nitric acids and to strong bases is on the level of 80–95%. The kinetics of sorption of Са2+ and Мg2+ ions from aqueous solutions onto the synthesized resin was studied in batch experiments, and the sorption equilibrium constants were determined. The capacity of the cation-exchange resin prepared for Ca2+ and Mg2+ ions remained unchanged after five sorption–desorption cycles. The resin synthesized can be used for water softening. [ABSTRACT FROM AUTHOR]

In this article, two aliphatic and aromatic types of dicationic acidic ionic liquids formulated as [H2-DABCO][ClO4], [H2-Bisim][ClO4]2 were used for the acceleration of the protection of alcohols as their corresponding trimethylsilyl (TMS), tetrahydropyranyl (THP) and methoxymethyl (MOM) ethers and the achieved results were compared. The performance of the catalyst was equal. All reactions were performed under mild conditions with good to high yields during short reaction times. Although in most cases the performance of both of the catalysts is equal, but TMS protection in the presence of [H2-Bisim][ClO4]2 needed lower amounts of the catalyst. [ABSTRACT FROM AUTHOR]

Nitinol is widely used in the production of medical devices, especially the ones that are designed for minimally invasive treatment, such as stents to restore vascular patency, stent grafts to eliminate aneurysms, and cava filters to trap blood clots. One of the most important characteristics that determines the reliability of the functioning of such products in the human body is the state of the surface layer. The higher the surface quality, the less negative impact is on the circulatory system, the walls of blood vessels and the higher the biological compatibility of the product. Electrochemical polishing methods are mainly used to improve the surface quality of nitinol products. The disadvantage of the applied electrochemical methods is the need to use aggressive electrolytes that contain toxic components, such as hydrofluoric acid, sulfuric acid, perchloric acid, nitric acid, methanol. As an alternative to the existing methods of electrochemical polishing, we have developed electrolytic-plasma polishing (EPP), a new highly efficient process for improving the surface quality of nitinol products. The most important advantage of the method over traditional electrochemical polishing is the use of aqueous salt solutions with a concentration of 4 % as electrolytes. Based on the results of the studies performed, the most rational EPP mode was established, the use of which during polishing of nitinol provides surface cleaning from scale, polishing with a decrease in the roughness parameter Ra by 0.344 μm and an increase in pitting potential by 33 %. [ABSTRACT FROM AUTHOR]

Plasma is an abundant source of proteins and potential biomarkers to aid in the detection, diagnosis, and prognosis of human diseases. These proteins are often present at low levels in the blood and difficult to identify and measure due to the large dynamic range of proteins. The goal of this work was to characterize and compare various protein precipitation methods related to how they affect the depth and breadth of plasma proteomic studies. Abundant protein precipitation with perchloric acid (PerCA) can increase protein identifications and depth of plasma proteomic studies. Three acid- and four solvent-based precipitation methods were evaluated. All methods tested provided excellent plasma proteomic coverage (>600 identified protein groups) and detected protein in the low pg/mL range. Functional enrichment analysis revealed subtle differences within and larger changes between the precipitant groups. Methanol-based precipitation outperformed the other methods based on identifications and reproducibility. The methods' performance was verified using eight lung cancer patient samples, where >700 protein groups were measured and proteins with an estimated plasma concentration of ∼10 pg/mL were detected. Various protein precipitation agents are amenable to extending the depth and breadth of plasma proteomes. These data can guide investigators to implement inexpensive, high-throughput methods for their plasma proteomic workflows., (© 2024 The Authors. PROTEOMICS published by Wiley‐VCH GmbH.)

Purpose: Fluoride uptake of enamel after application of fluoride varnishes was compared with fluoride release into artificial saliva. The hypothesis was that fluoride uptake is higher for products exhibiting faster fluoride release.Materials and Methods: Fluoride varnishes, i.e. Fluor Protector S, Duraphat, MI Varnish, Clinpro White Varnish, Profluorid Varnish and Enamel Pro Varnish were applied on bovine enamel specimens. Subsequently, specimens were incubated in artificial saliva. After removal of the varnishes, surface bound fluoride was extracted with potassium hydroxide and measured with an ion-selective electrode. Structurally bound fluoride was etched from the same specimens with perchloric acid. Fluoride release of varnish films into artificial saliva was measured for comparison.Results: After 4 h in artificial saliva, the highest total enamel fluoride uptake of 47.9 μg F·cm-² was found with Fluor Protector S, followed by Enamel Pro Varnish with 22.1 μg F·cm-². The other products ranged between 12-16 μg F·cm-². This was several times higher than the negative control. Fluoride uptake did not correlate with release into artificial saliva. During the first 4 h, Duraphat released the lowest and MI Varnish the highest amount of fluoride with 7.7 and 249 μg F·cm-², respectively. The fluoride uptake of these two products was not statistically different.Conclusion: Enamel fluoride uptake cannot be predicted from the fluoride release rate of a product. Hence, based on the results of this study, fluoride release into artificial saliva is no measure for the efficacy of a fluoride varnish. [ABSTRACT FROM AUTHOR]

Kinetics of Ir(III) catalysed oxidation of tartaric acid (TA) by N-chlorosuccinimide (NCS) in the presence of perchloric acid has been investigated in the temperature range of 300C to 450C. The reaction shows first order in both (NCS) and Ir (III)] and zero order in [(TA)]. First order kinetics with respect to [H+] was observed. Addition of chloride ions in the form of various amounts of KCl indicated positive effect of [Chloride] ions on the rate. Addition of various amounts of succinimide (reduction product of NCS) and increase in ionic strength of the medium showed negative effect on the rate of the reaction. Activation parameters have been calculated and reported. A suitable mechanism has been proposed and discussed. Rate law in conformity with observed kinetic results has been derived. [ABSTRACT FROM AUTHOR]

A pair of meso‐unsubstituted expanded carbaporphyrins containing two carbazole moieties were prepared in high isolated yields (82 and 76 %, respectively). The two macrocycles, namely 3 and 4, differ with respect to their substitution at the carbazole N‐atoms i. e. by H and i‐Bu, respectively. As prepared in their free‐base forms, macrocycles 3 and 4 adopt figure‐of‐eight conformations and are best characterized as 40 π‐electron, non‐aromatic species possessing a decaphyrin(1.1.0.0.0.1.1.0.0.0) skeleton. Protonation of 3 with either trifluoroacetic acid (TFA) or perchloric acid (HClO4) produces a parallelogram‐shaped structure. A similar structure is produced when N‐functionalized system 4 is treated with TFA. In contrast, protonation of 4 with HClO4 leads it to adopt a twisted Möbius strip‐like structure in the solid state, thus allowing access to three distinct conformational states as a function of the conditions. [ABSTRACT FROM AUTHOR]

New methods for extracting cobalt and zinc ions from sulfuric acid solutions, of silver and lead ions from nitric acid solutions, and of copper ions from hydrochloric acid solutions with liquid membranes based on di(2-ethylhexyl)phosphoric acid under conditions of galvanostatic electrodialysis with cathodic electrodeposition of metals are presented. Almost complete (93–100%) extraction from aqueous solutions with an initial concentration of metal salts of 0.01 M was achieved within 0.5–5.0 h of electrodialysis. The criterion of complete extraction of metal ions into a liquid membrane is an abrupt voltage rise in the galvanostatic mode of the process. The effects of the composition of the cathode solution, metal and acid concentration in the initial solution, composition of the organic liquid membrane, and current density of electrodialysis on the rate of extraction and electrodeposition of metal ions were studied. The optimum conditions for the processes were determined. Finely crystalline cobalt, silver, and lead cathode deposits with good adhesion to the electrode were obtained by electrodeposition from dilute perchloric acid solutions; high-quality copper coatings were obtained from sulfuric acid solutions; and zinc coatings, from hydrochloric acid solutions. [ABSTRACT FROM AUTHOR]

New bis-formazans and bis(5,6-dihydro-1,2,4,5-tetrazin-1-ium) perchlorates were synthesized with high yields under mild conditions. 1,1′-([1,1′-Biphenyl]-4,4′-diyl)bis(3-aryl-5-phenylformazans) were obtained by diazo coupling of para-substituted benzaldehyde phenylhydrazones with [1,1′-biphenyl]-4,4′-bis(diazonium chloride). Treatment of the obtained bis-formazans with formaldehyde in the presence of perchloric acid in dioxane afforded 1,1′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-5-phenyl-5,6-dihydro-1,2,4,5-tetrazin-1-ium) diper-chlorates. The structure of the synthesized compounds was confirmed by elemental analyses and UV, IR, and 1H and 13C NMR spectra. [ABSTRACT FROM AUTHOR]

Kinetics of Ru(III) catalysed oxidation of butane 1,3 diol by potassium bromate in perchloric acid have been studied and mercuric acetate has been used as bromide ion scavenger. The results indicate zero order dependence on potassium bromate and hydrogen ions while first order kinetics with respect to butane 1,3 diol and Ru(III) is observed. Successive addition of either of mercuric acetate or potassium chloride does not bring about significant change in the rate of reactions. Negligible effect of ionic strength on the rate of reaction was observed. The mechanistic steps in conformity with kinetic results have been suggested. [ABSTRACT FROM AUTHOR]

BACKGROUND: Standard mode with interference correction or kinetic energy discrimination mode is commonly used for the determination of trace silver in geochemical samples by inductively coupled plasma-mass spectrometry (ICP-MS). Interference of both stable isotopes of silver occurs in the mass spectrum of the oxides or hydroxides of zirconium and niobium. Moreover, for samples with a higher content of interfering elements and a lower content of silver, the determination accuracy is low, requiring separation of the interfering element from silver in the solution. OBJECTIVES: To develop a method for the determination of trace Ag in geochemical samples. METHODS: In this method, nitric acid, hydrofluoric acid and perchloric acid were used to digest the sample, which was evaporated to dryness and then redissolved with concentrated hydrochloric acid, with 5 mL of 0.05 mol/L phosphoric acid added. Most of the dissolved interfering elements of Zr and Nb were transformed into insoluble phosphate compounds, which were separated from the silver by precipitation. 103Rh was used as the internal standard to correct the instrument signal drift. The mass spectrum interference of 91Zr16O+ and 90Zr16O¹H+ on 107Ag was corrected by 106Pd. RESULTS: As proved by first grade standard materials, the result was consistent with standard recommended values, with the relative standard deviation of 4.3%-12.1%（n=12). The detection limit（3 SD) of the method was 0.0072μg/g. CONCLUSIONS: This method is suitable for the determination of trace silver in soil, stream sediment and rock samples. The introduction of phosphoric acid does not affect the determination of other conventional elements, and the same digestion solution can be used to determine Ag and other elements. [ABSTRACT FROM AUTHOR]

A low-cost reverse phase ultra-performance liquid chromatography (RP-UPLC) method for analyzing alfuzosin hydrochloride in the presence of impurities and degradation products from forced decomposition products has been developed. Several method development trials for the separation of drug from impurities were carried out. Furthermore, the best chromatographic separation was attained on a Waters Acquity HSS T3 C18, 100 mm x 2.1 mm, particle size 1.8, UV detection at 254 nm and gradient elution of perchloric acid (pH 3.5 with sodium hydroxide) with a mixture of organic solvents. (acetonitrile, tetrahydrofuan) as mobile phase for drugs. The method has been assessed for specificity/selectivity, linearity/range, repeatability, recovery, and reliability, which can be utilized for quality control during production, as well as to assess the stability of alfuzosin hydrochloride samples. The total elution time was about6.5 minutes, and the equilibration time was approximately 1.5 minutes, allowing for the analysis of more than 100 samples per day. Besides that, the pH sensitive analytical method addressed in the US Pharmacopoeia and the European Pharmacopoeia was discussed. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) mixed with single-wall nanotubes (SWNTs) (10:1) and doped with (0.1 M) perchloric acid (HClO4) in a solution-processed film, working as an excellent thin transparent conducting film (TCF) in organic solar cells, was investigated. This new electrode structure can be an outstanding substitute for conventional indium tin oxide (ITO) for applications in flexible solar cells due to the potential of attaining high transparency with enhanced conductivity, good flexibility, and good durability via a low-cost process over a large area. In addition, solution-processed vanadium oxide (VOx) doped with a small amount of PEDOT-PSS(PH1000) can be applied as a hole transport layer (HTL) for achieving high efficiency and stability. From these viewpoints, we investigate the benefit of using printed SWNTs-PEDOT-PSS doped with HClO4 as a transparent conducting electrode in a flexible organic solar cell. Additionally, we applied a VOx-PEDOT-PSS thin film as a hole transporting layer and a blend of PTB7 (polythieno[3,4-b] thiophene/benzodithiophene): PC71BM (phenyl-C71-butyric acid methyl ester) as an active layer in devices. Zinc oxide (ZnO) nanoparticles were applied as an electron transport layer and Ag was used as the top electrode. The proposed solar cell structure showed an enhancement in short-circuit current, power conversion efficiency, and stability relative to a conventional cell based on ITO. This result suggests a great carrier injection throughout the interfacial layer, high conductivity and transparency, as well as firm adherence for the new electrode. [ABSTRACT FROM AUTHOR]

The metal complex in the FcCH2OH–HClO4–p-benzoquinone system is oxidized with p-benzoquinone as well as with the hydrogen ion as a result of its protonation. Involvement of the acid in both processes determines their influence of each of them on the rate of the other one. This fact has been confirmed by the obtained dependences of the rate of ferrocenium ions accumulation during protonation and oxidation of FcCH2OH on the reactants concentrations as well as by the derived kinetic equations of the processes. The degree of their mutual influence depends on the solvating properties of the solvents and the ratio of the starting concentrations of the metal complex and the acid, which affect the yield of the FcC+H2 carbocation and its ability to redox isomerism upon protonation of the metal complex. [ABSTRACT FROM AUTHOR]

In aqueous perchloric acid medium (pH = 0.522 - 1.3), N-benzylhydroxylamine (two electron reductant) reduces the one electron oxidant, superoxo ligand in [(dien)(en)CoIII(O2)CoIII(en)(dien)](ClO4)5 (1) to the corresponding hydroperoxo complex, [(en)(dien)CoIII(HO2)CoIII(en)(dien)]5+ (2) and itself gets oxidised to PhCH2NO following both proton coupled electron transfer path and an electron transfer reaction. The kinetics, stoichiometry and reaction mechanism clearly indicate that oxidation of PhCH2NHOH occurs through the formation of an intermediate, benzyl derivative of aminoxyl radical (PhCH2NHO•). In the presence of excess PhCH2NHOH over 1, the reaction obeys first-order kinetics and rate of the reaction increases with [PhCH2NHOH]. The reaction rate, however, decreases with increase in [H+] and the plot of 1/ko with [H+] is linear with a small but noteworthy intercept. It is also remarked that the reaction rate remarkably decreases with increasing proportion of D2O replacing H2O in the solvent. Therefore, an H-atom transfer from PhCH2NHOH to the bridging superoxide in 1 seems reasonable at the rate determining step. [ABSTRACT FROM AUTHOR]

Kinetics of oxidation of L-lysine by permanganate ion in a perchloric acid medium was investigated to explore the order of the reaction with respect to oxidant and substrate and to study the catalytic behaviour of sodium lauryl sulphate (SLS) and polyethylene glycol (PEG). The reaction was found to be first-order with respect to the oxidant and the substrate and zero-order with respect to hydrogen ion. Changes in the sodium sulphate concentration produce a non-significant variation in the rate of the reaction. SLS and PEG were found to catalyze the reaction. Surfactant catalysis was modelled by Piszkiewicz's cooperativity model, while polymer catalysis was explained with the help of the Benesi-Hildebrand equation. The temperature dependence of the rate of the reaction was elucidated, and activation parameters were obtained. Interestingly, the reaction was found to possess positive activation entropy indicating the dissociative nature of the transition state and outer-sphere electron transfer mechanism. A mechanism of the reaction that is supported by the experimental findings was suggested. [ABSTRACT FROM AUTHOR]

Background: Our purpose was to evaluate the performance of the ACCU-CHEK® Inform II blood glucose monitoring system (Roche Diagnostics GmbH) compared with the perchloric acid hexokinase (PCA-HK) comparator method on the cobas® 6000 analyzer (Roche Diagnostics International Ltd) in critically ill patients. Methods: Overall, 476 arterial (376 pediatric/adult, 100 neonate), 375 venous, and 100 neonatal heel-stick whole-blood samples were collected and evaluated from critical care settings at 10 US hospitals, including the emergency department, medical and surgical intensive care units (ICUs), and neonatal and pediatric ICUs. The ACCU-CHEK Inform II system was evaluated at 2 cutoff boundaries: boundary 1 was ≥95% of results within ±12 mg/dL of the reference (samples with blood glucose <75 mg/dL) or ±12% of the reference (glucose ≥75 mg/dL), and boundary 2 was ≥98% of results within ±15 mg/dL or ±15% of the reference. Clinical performance was assessed by evaluating sample data using Parkes error grid, Monte Carlo simulation, and sensitivity and specificity analyses to estimate clinical accuracy and implications for insulin dosing when using the ACCU-CHEK Inform II system. Results: Proportions of results within evaluation boundaries 1 and 2, respectively, were 96% and 98% for venous samples, 94% and 97% for pediatric and adult arterial samples, 84% and 98% for neonatal arterial samples, and 96% and 100% for neonatal heel-stick samples. Clinical evaluation demonstrated high specificity and sensitivity, with low risk of potential insulin-dosing errors. Conclusions: The ACCU-CHEK Inform II system demonstrated clinically acceptable performance against the PCA-HK reference method for blood glucose monitoring in a diverse population of critically ill patients in US care settings. [ABSTRACT FROM AUTHOR]

Different methods have been presented to extract and measure glycogen in animal tissues. The current study performed to resolve the problems encountered in the new protocol to assay glycogen fractions. The new method has four phases of tissue digestion, extraction, fractionation and measurement. The tissue was weighed and digested with hot KOH and total glycogen was precipitated with ethanol. The suspension of total glycogen was separated into the fractions of acid soluble (ASG) and insoluble (AIG) by adjusting the pH. The recovery of total glycogen during precipitation with ethanol was insensitive to temperature. But, chemical method of phenol-sulfuric acid was highly dependent on the air temperature of the laboratory. The recovery of total glycogen increased significantly by about 25% at 4000 rpm and reached the plateau. The pellet of total glycogen was washed with ethanol to eliminate excess KOH and to reduce the values of perchloric acid and KOH to minimum essential volumes for adjusting the pH. This prevented over-production and precipitation of KClO4. It is concluded that, the ambient temperature is an important factor that affects the chemical assay. Minor modifications of the new protocol improved the analysis. [ABSTRACT FROM AUTHOR]

The commonly used Chromsystems vitamin C (ascorbate) assay (Munich, Germany) has a sample storage life of five days at -20°C. Stabilizing agents have been successfully used to increase longevity; however, their suitability with this commercial assay is unclear. We investigated the compatibility of a stabilizing agent, perchloric acid/diethylenetriaminepentaacetic acid (PCA/DTPA), with the Chromsystems assay. Plasma was stored at -80°C, with or without PCA/DTPA. Storage up to six months was assessed through baseline and repeat analyses, stability was assessed by comparing paired non-stabilized and PCA/DTPA-stabilized plasma, and performance was assessed using allowable performance specifications of an external quality assurance program. Ascorbate concentration was significantly lower in non-stabilized plasma than in paired PCA/DTPA-stabilized plasma, with a proportional difference of 11% (P =0.01). All storage analysis results were within the allowable performance specifications. Storage at -80°C prevented plasma ascorbate oxidation; however, substantial oxidation occurred during sample processing. In conclusion, PCA/DTPA significantly reduces ascorbate oxidation, and PCA/DTPA-stabilized ascorbate plasma is compatible with the Chromsystems assay and stable for up to six months, when stored at -80°C. [ABSTRACT FROM AUTHOR]

In this work, three novel 1,4-butane sultone-based Brønsted acidic ionic liquids with Perchlorate conter-anion are prepared. These newly introduced ionic liquids were synthesized from a two-steps reaction. The reaction includes ring opening of 1,4-butane sultone using 1,4-dimethylpiperazine or 1,10-phenantroline as nitrogen nucleophile sources to obtain zwitterions and then follow by acidification treatment with perchloric acid to obtain three novel Brønsted acidic ionic liquids. The prepared task specific ionic liquids and their stable intermediates were characterized by FT-IR, 1HNMR, 13C-NMR, UV–Vis, TGA and CHNS analysis techniques. The prepared ionic liquids are fully water soluble and have good thermal stability up to 200 °C or higher. Their catalytic efficiency was checked for the preparation of symmetric 3,3′-diaryloxindoles compounds. It was found that the introduced acidic ionic liquids are completely green, environmental benign, task specific and have high catalytic stability. These novel acidic ionic liquids are simply separable by extraction from organic phase by solving in water up to six consecutive runs and give the target products in short reaction times at high yields. [ABSTRACT FROM AUTHOR]

Introduction: Exponential research and development of nanotechnology has lead to its implementation in medical line such as radiographic imaging. In current practice, iodine is clinically used as a contrast media in radiographic analyses. However, contraindication of iodine to kidney in clinical practice warrants for a better contrast enhancer with lower toxicity. Gold nanoparticles (GNPs) and Iron Oxide nanoparticles (IONPs) have been proposed as potential iodine's substitute due to their novel biocompatibility. Methods: In accordance with technology-driven toxicity impact, an animal modeling study has been conducted to assess the nephrotoxicopathology of GNPs and IONPs with Perchloric Acid and SiPEG by biochemical study, in-depth tissue examination by histopathology, apoptosis, and ultrastructural observation, and molecular analysis by Comet Assay. Results: Renal function test (RFT) revealed significant alteration in iodine group compared to nanoparticles and negative control group (p<0.05). Reactive oxygen species (ROS) generation and lipid peroxidation (MDA) levels demonstrated significant reduction in both nanoparticles' groups compared to iodine (p<0.05), suggesting for lower oxidative stress induction. Morphological aberration demonstrated by histology and ultrastructural evaluation (TEM) showed a distortion in kidney tissues and nucleus' structure of iodine-administered group as compared to control and nanoparticles' group. Apoptosis detection by TUNEL assay for GNPs and IONPs group also revealed a significant reduction in apoptotic cells compared to iodine group. Comet assay revealed significant reduction in DNA damaging effect of GNPs and IONPs group compared to iodine group. Conclusion: The present study may postulate that GNPs and IONPs show better contrast enhancer properties with lesser toxic properties than iodine [ABSTRACT FROM AUTHOR]

The asynchronous transient responses at the edge and center of a gold disk electrode are monitored by in situ differential reflectance spectroscopy (DRS). The DRS spectrum collected in 10 mM perchloric acid shows that the edge of the electrode achieves the equilibrium sooner than the center does in chronoamperometry, which establishes the foundation for a similar electrochemical protocol to remove the metallic Cu at the edge of a Cu/Au disk electrode while keeping these at the center intact. Both phenomena are caused by the larger resistance at the center than the edge of a disk electrode. [ABSTRACT FROM AUTHOR]

BACKGROUND: Inductively coupled plasma - mass spectrometry ( ICP - MS) is used for the determination of trace silver in geological samples. Hydroxides and oxides of Zr, Nb, Mo cause serious overlapping interference on the two mass numbers of 107 Ag and 109 Ag, which can result in a significant deviation of the results. OBJECTIVES: To develop a method for precise determination of trace Ag in geological samples. METHODS: Considering that the MS interference of 107 Ag is relatively simple and only 90Zr16 OH+ and 91 Zr16 0 + have interferences on 107 Ag, 107 Ag was selected for the determination of silver in ICP - MS analysis. In the sample pretreatment, hydrofluoric acid, perchloric acid and nitric acid were used for open digestion, and excessive ammonia was added to the extraction solution. The main interference element Zr of 107 Ag was separated by precipitation. Trace silver was determined with Re as the internal standard to complement matrix effect and signal drift. RESULTS: The content of trace silver in national standard materials of stream sediment, rock and soil was determined by ICP - MS. The test value was consistent with the certified value. The detection limit of the method was 0. 0031 µgig, and the relative standard deviation ( RSD) was 4. 38%. CONCLUSIONS: The method has the advantages of simple and accurate measurement of trace silver. Moreover, common metal elements can be determined before adding ammonia to the leaching solution, so that the extraction solution can be recycled. [ABSTRACT FROM AUTHOR]

Low‐dose methotrexate is the first‐line therapy for juvenile idiopathic arthritis. In vivo, methotrexate is converted into a series of methotrexate polyglutamates whose intracellular levels contribute significantly to its efficacy and toxicity. In this study, a novel high‐performance liquid chromatography–tandem mass spectrometry method was developed and validated to simultaneously determine erythrocyte methotrexate polyglutamates using stable isotope‐labeled internal standards. Erythrocyte samples were precipitated by perchloric acid and then determined on an XBridge BEH C18 column with an XP vanguard precolumn in 12 min. The mobile phase consisted of 10 nM ammonium acetate (pH 10) and methanol under gradient elution. The detection was carried out in multiple reaction monitoring mode via an electrospray ionization source in positive ionization mode. The calibration curve for each metabolite was linear from 2.0 to 500.0 nmol/L (r2 > 0.99). The intraday and interday accuracies were between 93.0 and 107.0%, and the corresponding precisions were between 0.8 and 5.2%. The relative recovery ranged from 82.7 to 105.1%, and the relative matrix effect varied from 96.5 to 104.4%. The erythrocyte metabolites were stable for 30 days at −80°C. This simple and accurate method is applicable to routine monitoring of the concentration of erythrocyte methotrexate polyglutamates in patients to achieve individualized treatment. [ABSTRACT FROM AUTHOR]

A series of 3,3′-(1,4-phenylene)bis(1-4-R-phenyl)-5-phenyl-5,6-dihydro-1,2,4,5-tetrazinium) perchlorates (R = H, Me, Cl, OMe, CN, NO2) were obtained as a result of a three-stage synthesis from terephthalic aldehyde. The synthesis of tetrazinium salts was carried out by reaction of the corresponding formazans with formalin in the presence of perchloric acid in dioxane. Formazans and tetrazinium perchlorates were isolated in individual state and characterized by elemental analysis, IR, UV, 1H, and 13C NMR spectroscopy data. The process of electrochemical reduction of tetrazinium perchlorates was studied using the method of cyclic voltammetry (CV). It has been shown that these compounds are perspective precursors of symmetric biradical systems based on verdazyl radicals. [ABSTRACT FROM AUTHOR]

The electropolymerization of Metanil Yellow was investigated in aqueous solutions containing inorganic acids (sulphuric, hydrochloric, nitric, phosphoric and perchloric acid) as well as sulphonic acids (5-sulpho salicylic acid, sulphanilic acid, dodecylbenzene sulphonic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) and lauryl sulphate in its acidic solution. By the inorganic ions the conductivity increased in the sulphate, chloride, nitrate, perchlorate serie. Of the organic sulphonic compounds 5-sulpho-salicylic acid was found to be a very efficient dopant in increasing polymer conductivity being obviously better than the other sulphonate anions. The formed conducting polymer was not suitable for detection of the corresponding anion. Nitrite ions completely diminished the electric properties of the polymer due to the reaction resulting nitrosamine. [ABSTRACT FROM AUTHOR]

The combination of two bidentate Ph2P(O)CH2C(O)N(Alk)-fragments in one molecule via amide nitrogen atom by alkylene bridge has been found to result in marked increase in REE(III) extraction from perchlorate solutions. The stoichiometry of recovered complexes has been determined. The effect of extractant structure, HClO4 concentration in aqueous phase, and organic solvent nature on the efficiency of REE(III) ions extraction into organic phase has been considered. [ABSTRACT FROM AUTHOR]

There are three basic modalities for the treatment of thyrotoxicosis: thyrosuppresive drug therapy, ablation with radioactive iodine and surgical treatment. Patients who do not achieve adequate thyrotoxicosis control, as was the case of described patient, have a high mortality rate due to the possibility of developing a thyroid storm. The use of drug therapy for hyperthyroidism, as the first line of treatment, is associated with the appearance of various side effects, as was the case in our patient. Side effects of Methimazole are dose-dependent, while in the case of Propylthiouracil, the occurrence of side effects is not clearly dose-dependent. In the case of the described patient, all alternative, lesser known modalities for the treatment of hyperthyroidism were applied, after the occurrence of adverse reactions to thyrosuppressive therapy. Sodium perchlorate, ie. Sodium with perchloric acid is rarely used in the treatment of hyperthyroidism, as in cases of severe idiosyncratic reactions to thionamides, agranulocytosis or hepatitis, if the eumetabolic state is not achieved and the application of a therapeutic dose of radioiodine is not possible. It is applied in the form of a solution, usually 8%; In more severe forms of the disease, when hyperthyroidism is very pronounced, 10 to 15 drops a day are given 4 to 6 times and the dose is sometimes reduced to the minimum maintenance dose. After the adverse reaction even to sodium perchlorate therapy we were left with one more, last option- Plasma Therapy exchange. Plasma Therapy Exchange (TPE) is an out-of-body blood purification technique designed to remove high-molecular-weight substances bound to plasma proteins (autoantibody pathogens, immunocomplexes, cryoglobulins, myeloma light chains, endotoxins, lipoprotein-containing cholesterol, and thyroid). The effectiveness of treatment depends on the volume of blood being processed, the volume of plasma exchanged in each process, the number of procedures performed, the frequency of exchange and the rate of mobilization, stabilization and re-synthesis of cells or plasma components. TPE is an effective alternative treatment that provides an opportunity to prepare patients for definitive treatment: ablative therapy such as RAI ablation or thyroidectomy. Therapeutic plasmapheresis, if performed in specialist centers, is a safe, fast and effective method. [ABSTRACT FROM AUTHOR]

The article describes an analysis example of the physiochemical and pharmacokinetic properties of active pharmaceutical ingredients using ion exclusion chromatography. Topics discussed include analytical conditions that can achieve good separation of the components of formic acid, acetic acid, fumaric acid, and maleic acid by using LabSolutions MD, design space for parameters and responses, and proposal of optimal analytical conditions.

Spectrophotometry has been used to examine the kinetics of Np(V) disproportionation in HCOOH solutions containing H2O and HClO4 at temperatures of 20–45°C. The reaction rate is described in the initial portion by the equation –d[Np(V)]/dt = k[Np(V)]2. The rate constant k sharply grows with increasing [HClO4] (order n = 3.5) and with decreasing content of H2O (n = –2.30. The appearing Np(VI) is slowly reduced to Np(V) by formic acid. The activation energy of the disproportionation reaction is 54 kJ mol–1. The mechanism includes the elimination of an H2O molecule from the H+aq ion and addition of a proton to NpO2+. The protonated Np(V) ions form a dimer which is an activated complex. The H transfer in this complex yields Np(IV) and Np(VI). [ABSTRACT FROM AUTHOR]

The objective was describing the use of kaolin as an extern marker in the dry matter supplement intake and fecal output of cattle grazing. Many markers have limitations, kaolin is a possible intake marker with applicability, because it has acceptable physical and chemical characteristics. The quantification is performed indirectly by aluminum present in the substance, and determined by colorimetric method with aluminon. Currently, research in animal nutrition has presented interesting information, however, flaws in the analytical methodology of kaolin have shown unsatisfactory results. An effective alternative is nitro perchloric acid digestion associated with hydrofluoric acid. So, research for new practical and low-cost methodologies that present accurate and robust results is still necessary. [ABSTRACT FROM AUTHOR]

The rapid growth in demand for peptide drugs is actualizing the search for new natural and economically viable sources of raw materials. The wide variety of biologically active compounds, including peptide nature, inherent in marine aquatic organisms allows us to consider their promising raw material resource. However, the use of marine objects as a source for the production of target molecules requires some optimization of existing methodological approaches to their isolation and ensure the appropriate degree of purification. The problem of optimization of the method of obtaining peptides from hydrobionts of the Antarctic region on the example of the hydrobiont Nacellaconcinna is solved in the work. The proposed three-step approach allows to isolate fractions of peptides of different molecular weight. The first step involved the precipitation of high molecular weight protein material first with perchloric acid and then with 80% ethyl alcohol. The result was a fraction of peptide molecules with a molecular weight of up to 6.5 kDa, which contained a small amount of high molecular weight protein impurities. Further purification of the obtained fraction was performed by ultrafiltration using membranes with a pore size of 10 kDa. Control of the protein-peptide composition of the sample at all stages of production was performed by disk electrophoresis under denaturing conditions in plates of 18% polyacrylamide gel. Analysis using 2D electrophoresis found that the isoelectric points of most peptides are in the pH range from 8.0 to 10.0. Only a small proportion of the peptides had isoelectric points at 4.0 and 5.0 pH. The final step of obtaining the peptide fraction involved fractionation of the sample by gel chromatography. As a result of chromatographic separation, four peaks were obtained, corresponding to the fractions with peptides, the molecular weight of which is about 2.3 kDa (1 peak), 1.9 kDa (2 peak), 1.4 kDa (3 peak) and 0.7 kDa (4 peak). [ABSTRACT FROM AUTHOR]

This work studies the actuation of hybrid materials made from nanoporous gold, polypyrrole, and aqueous electrolyte. The deposition protocol affords a conformal polypyrrole coating on the entire internal interface of millimeter‐sized nanoporous metal specimens made by dealloying. The hybrid material emerges when the remaining pore space is filled with perchloric acid. The metal serves as load‐bearing and electronically conductive substrate, the polypyrrole as functional active component for actuation, and the aqueous electrolyte provides a pathway for fast ionic conduction. In this way, an actuator material is obtained that can be manufactured as monolithic bodies that can be subjected to compressive loads. Actuators with dimensions of millimeters in each spatial direction achieve characteristic times for actuation in the order of seconds and their work density is comparable to that of state‐of‐the‐art piezoceramics. As a remarkable finding, the actuation strain scales with the square of the polypyrrole phase fraction. This is surprising in view of the linear scaling predicted by conventional micromechanical models. A micromechanical model that explains this behavior as the result of polypyrrole bridges that link adjacent struts of the metal skeleton is presented. [ABSTRACT FROM AUTHOR]

Green validated spectrophotometric methods are developed for simultaneous determination of Azithromycin (AZI) and Levofloxacin (LEVO) antibiotic mixture. Determination of AZI presents a real analytical challenge as its structure lacks any chromophore, and hence it cannot be determined by direct spectrophotometry. However, the reaction of AZI with perchloric acid produces a green product that can be accurately determined spectrophotometrically. Thus, the work presented demonstrates simple green and sensitive methods for the simultaneous determination of AZI and LEVO mixture. Method I depends on direct measurement of absorbance of azithromycin and levofloxacin in perchloric acid methanolic solution at 482 nm and 224 nm, respectively. While, Method II depends on measuring the first derivative spectrophotometric peak-to-peak amplitudes of AZI and LEVO in perchloric acid methanolic solution at 475–490 nm and 280–253 nm, respectively. Regression analysis shows good linearity for AZI and LEVO over the concentration ranges of 5–50 and 2.5–20 μg/mL for method I and 5–50 and 5–40 μg/mL for method II for AZI and LEVO, respectively. The proposed methods were validated in compliance with ICH guidelines. The suggested procedures are successfully applied for the assay of AZI and LEVO mixture in bulk powder and laboratory-prepared tablets. Greenness profile of the proposed methods were compared with other published methods through applying the Eco-scale protocol. Assessment results demonstrated that the proposed methods are greener than other reported methods. Moreover, upon comparison with other methods, the proposed methods showed better or comparable sensitivity in addition to being selective and rapid with no requirement for laborious extraction techniques. These advantages encourage the application of the proposed methods in routine analysis of AZI and LEVO in quality control laboratories as green and simple analytical tool.

Novel dissimilatory perchlorate-reducing bacteria (DPRB) were isolated from enrichments conducted under conditions different from those of all previously described DPRB. Strain LT-1(T) was enriched using medium buffered at pH 6.6 with 2-(N-morpholino)ethanesulfonic acid (MES) and had only 95% 16S rRNA gene identity with its closest relative, Azonexus caeni. Strain MP(T) was enriched in the cathodic chamber of a perchlorate-reducing bioelectrical reactor (BER) and together with an additional strain, CR (99% 16S rRNA gene identity), had 97% 16S rRNA gene identity with Propionivibrio limicola. The use of perchlorate and other electron acceptors distinguished strains MP(T) and CR from P. limicola physiologically. Strain LT-1(T) had differences in electron donor utilization and optimum growth temperatures from A. caeni. Strains LT-1(T) and MP(T) are the first DPRB to be described in the Betaproteobacteria outside of the Dechloromonas and Azospira genera. On the basis of phylogenetic and physiological features, strain LT-1(T) represents a novel genus in the Rhodocyclaceae; strain MP(T) represents a novel species within the genus Propionivibrio. The names Dechlorobacter hydrogenophilus gen. nov., sp. nov and Propionivibrio militaris sp. nov. are proposed.