Construction of ferritin hydrogels utilizing subunit–subunit interactions

Various proteins form nanostructures exhibiting unique functions, making them attractive as next-generation materials. Ferritin is a hollow spherical protein that incorporates iron ions. Here, we found that hydrogels are simply formed from concentrated apoferritin solutions by acid denaturation and subsequent neutralization. The water content of the hydrogel was approximately 80%. The apoferritin hydrogel did not decompose in the presence of 1 M HCl, 2-mercaptoethanol, or methanol but was dissolved in the presence of 1 M NaOH, by heating at 80°C, or by treatment with trypsin or 6 M guanidine hydrochloride. The Young’s modulus of the hydrogel was 20.4 ± 12.1 kPa according to local indentation experimentes using atomic force microscopy, indicating that the hydrogel was relatively stiff. Transition electron microscopy measurements revealed that a fibrous network was constructed in the hydrogel. The color of the hydrogel became yellow-brown upon incubation in the presence of Fe3+ ions, indicating that the hydrogel adsorbed the Fe3+ ions. The yellow-brown color of the Fe3+-adsorbed hydrogel did not change upon incubation in pure water, whereas it became pale by incubating it in the presence of 100 mM ethylenediaminetetraacetic acid (EDTA). The apoferritin hydrogel also adsorbed Co2+ and Cu2+ ions and released them in the presence of EDTA, while it adsorbed less Ni2+ ions; more Fe3+ ions adsorbed to the apoferritin hydrogel than other metal ions, indicating that the hydrogel keeps the iron storage characteristic of ferritin. These results demonstrate a new property of ferritin: the ability to form a hydrogel that can adsorb/desorb metal ions, which may be useful in designing future biomaterials.

Chemical Treatment of Highly Toxic Acid Mine Drainage at A Gold Mining Site in Southwestern Siberia, Russia

The critical environmental situation in the region of southwestern Siberia (Komsomolsk settlement, Kemerovo region) is the result of the intentional displacement of mine tailings with high sulfide concentrations. During storage, ponds of acidic water with incredibly high arsenic (up to 4 g/L) and metals formed on the tailings. The application of chemical methods to treat these extremely toxic waters is implemented: milk of lime Ca(OH)2, sodium sulfide Na2S, and sodium hydroxide NaOH. Field experiments were carried out by sequential adding pre-weighed reagents to the solutions with control of the physicochemical parameters and element concentrations for each solution/reagent ratio. In the experiment with Ca(OH)2, the pH increased to neutral values most slowly, which is contrary to the results from the experiment with NaOH. When neutralizing solutions with NaOH, arsenic-containing phases are formed most actively, arsenate chalcophyllite Cu18Al2(AsO4)4(SO4)3(OH)24·36H2O, a hydrated iron arsenate scorodite, kaatialaite FeAs3O9·8H2O and Mg(H2AsO4)2. A common specificity of the neutralization processes is the rapid precipitation of Fe hydroxides and gypsum, then the reverse release of pollutants under alkaline conditions. The chemistry of the processes is described using thermodynamic modeling. The main species of arsenic in the solutions are iron-arsenate complexes; at the end of the experiments with Ca(OH)2, Na2S, and NaOH, the main species of arsenic is CaAsO4−, the most toxic acid H3AsO3 and AsO43−, respectively. It is recommended that full-scale experiments should use NaOH in the first stages and then Ca(OH)2 for the subsequent neutralization.

Pre-Dehalogenation of Chlorine-Containing Medical Waste

The results of the study of the destruction of a model mixture of medical waste (MW) of typical composition and their components in the range of pyrolysis temperature of 400–650 °C are presented. It is shown that during the initial stage of waste heating by the time the temperature reaches 350 °C, 86–88 % of chlorine in the form of hydrogen chloride (HCl) passes into the gas phase. Considered developed and protected by the patent of the Russian Federation scheme of organization of thermal utilization of MW by two-stage pyrolysis with the removal of HCl from the gas stream at the first stage of the process with its subsequent neutralization with an alkaline solution, which significantly reduces the possibility of the formation of dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) in the second stage of pyrolysis, gaseous products in the form of a concentrated gas-vapor mixture are burned at a temperature of 1000–1350 °C, which ensures fire destruction of all the organic components of pyrolysis and environmental safety of exhaust flue gases.

Activated Carbon Obtained from Coffee and Orange Wastes

Organic coffee and orange wastes have increased considerably in the last decade. In order to utilize this "garbage", the present study focuses on the obtaining of activated carbon from them. The pyrolysis of the samples, followed by chemical activation and subsequent neutralization, allowed the establishment of two protocols “A” and “B”, with slight variations depending on the residue. The results indicate that the efficiency of the activated carbon from coffee grounds using protocol "A" and "B" was 3.68% and 6.30%, respectively. On the other hand, the carbon obtained from orange peels had an efficiency of 5.00 % and 2.88 %, respectively. To confirm that the activated carbon from each type of waste has adsorption and absorption capacity, we performed a colorimetric analysis with methyl blue. These analyses showed that the activated carbon from coffee grounds and orange peels have a retention capacity of 91.09 and 95.25%, respectively, while the retention capacity of a commercial activated carbon was 99.23 %. In this preliminary study, it is shown that several residues considered "garbage" can be used sustainably.

Antiseptic properties of aminoadamantane derivative

Development of microbial resistance to current antimicrobial drugs created a critical need of the new antiseptics. The object of our study was phenyladamantane derivative (4-(adamantyl-1)-1-(1-aminobutyl)benzol, AM-166). The aim of the presented study was to investigate the specific activity of 4% AM-166 solution in isopropanol and 5% AM-166 solution in 76% ethanol (manufactured by PJSC SIC «Borshchahivskiy CPP») against the wide spectrum of bacteria and fungi, and effective concentrations and exposition time determination. Desinfectant/antiseptic activity was evaluated by quantitative suspension method with subsequent neutralization. Our results showed that both solutions exhibited similar activity against gram-positive and gram-negative bacteria as well as against yeasts. Antibacterial and antifungal action was demonstrated for all investigated concentrations (initial solution, 5-fold and 10-fold dilutions), observed effect was maintained throughout the whole observation period (from 5 to 30 min). Tested solutions in initial concentrations demonstrated fungicidal activity against A. niger. 5-fold dilution of 5% AM-166 solution in 76% ethanol was more effective than 5-fold dilution of 4% AM-166 solution in isopropanol. 10-fold dilutions of both solutions were ineffective against A. niger. The data obtained suggest the prospects of adamantane derivatives for the development of novel antiseptics.

Determination of Free and Total Carnitine and Choline in Infant Formulas and Adult Nutritional Products by UPLC/MS/MS: Single-Laboratory Validation, First Action 2014.04

A single-laboratory validation (SLV) has been performed for a method that simultaneously determines choline and carnitine in nutritional products by ultra performance LC (UPLC)/MS/MS. All 11 matrixes from the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) were tested. Depending on the sample preparation, either the added (free, with a water dilution and filtering) or total (after microwave digestion at 120°C in nitric acid and subsequent neutralization with ammonia) species can be detected. For nonmilk containing products, the total carnitine is almost always equal to the free carnitine. A substantial difference was noted between free and total choline in all products. All Standard Method Performance Requirements for carnitine and choline have been met. This report summarizes the material sent to the AOAC Expert Review Panel for SPIFAN nutrient methods for the review of this method, as well as some additional data from an internal validation. The method was granted AOAC First Action status for carnitine in 2014 (2014.04), but the choline data are also being presented. A comparison of choline results to those from other AOAC methods is given.

Quality Improvement of Sugar by Two Factor Factorial Experimentation in Optimization of Quantity of Lime and Sulphur Added in the Juice Sulphitation Process of a Sugar Plant

Sugar industry is one of the vital sectors in improving the economy of any country. But, sugar industries are striving hard to increase their profitability due to high cost of sugar production accompanied with low selling price. Without resorting to radical restructuring of sugar plant, but through proper planning, annual savings can be improved. One of the artifices to address this issue is through improving the quality of sugar so that selling price can be increased which in turn generates more revenue to the plant. The Juice Sulphitation process, as applied in the manufacturing of sugar, is a subject of such wide-spread interest. The mixed juice from the mills contains soluble and non-soluble suspended non-sugars. These impurities are to be precipitated by the judicious and controlled addition of Milk of Lime (CaO) and subsequent neutralization by Sulphur Dioxide (SO2) gas. This paper attempts to improve the quality of sugar by optimizing the quantity of lime (in the form of milk of lime) and sulphur (in the form of SO2 gas) added in the juice sulphitation process of a sugar plant. Two factor factorial experimentation was adopted to obtain an optimal combination of lime and sulphur quantities. Data of Transmittancy test on sugar juice was collected by varying the quantities of lime and sulphur. Analysis of Variance (ANOVA) table was plotted which explored the significant effects of individual treatments and interaction effects. Further to this, comparison of treatment means was carried out to find out the best treatment combination values for achieving the optimal quality of sugar from sugarcane.

Modified AOAC Three Step Method (Official Method 2008.05): Consolidation of Fractions B and C

The AOAC Quantitative Three Step Method (TSM; AOAC Official MethodSM 2008.05) is validated for testing the efficacy of liquid sporicides against spores of Bacillus subtilis and Bacillus anthracis on selected hard, nonporous, and porous surfaces. The TSM uses 5 × 5 × 1 mm inoculated coupons (carriers), which are placed in 400 μL liquid sporicidal agent contained in a microcentrifuge tube. Following exposure of inoculated carriers to the test chemical and subsequent neutralization, viable spores are recovered in three fractions: A (gentle tapping), B (sonication), and C (gentle agitation). The spores in suspension are serially diluted and plated on a recovery medium for enumeration. The plate counts are summed over the three fractions to provide the number of viable spores per carrier, which is log10-transformed to generate a mean log density (LD) value across carriers. As a measure of product efficacy, a log reduction (LR) value is calculated by subtracting the mean LD for treated carriers from the mean LD for control carriers. This paper reports on the comparative evaluation of the current and modified versions of the TSM in order to support a modification to simplify the procedure. The proposed modified TSM (mTSM) consolidates fractions B and C in the same tube. Thus, the sonication (fraction B) and gentle agitation (fraction C) steps are carried out in the same tube, thereby reducing the number of tubes and associated resources and time necessary to complete the test. Glass, steel, pine wood, and ceramic tile carriers were included in the comparative study. Inoculated carriers were evaluated against two preparations of sodium hypochlorite to generate two presumed levels of efficacy (intermediate and high); the control LD and LR values associated with testing each carrier type for the TSM and the mTSM were compared. For control carriers, the mean log densities per carrier (for each carrier material) were not significantly different based on the TSM compared to the mTSM. Furthermore, the treated carrier data showed comparable LR values for the TSM and mTSM. The data provided in this report demonstrate equivalency between the TSM and mTSM and support the proposed procedural modification to consolidate fractions B and C.

The roles of sulfuric acid in new particle formation and growth in the mega-city of Beijing

Simultaneous measurements of gaseous sulfuric acid and particle number size distributions were performed to investigate aerosol nucleation and growth during CAREBeijing-2008. The analysis of the measured aerosols and sulfuric acid with an aerosol dynamic model shows the dominant role of sulfuric acid in new particle formation (NPF) process but also in the subsequent growth in Beijing. Based on the data of twelve NPF events, the average formation rates (2–13 cm−3 s−1) show a linear correlation with the sulfuric acid concentrations (R2=0.85). Coagulation seems to play a significant role in reducing the number concentration of nucleation mode particles with the ratio of the coagulation loss to formation rate being 0.41±0.16. The apparent growth rates vary from 3 to 11 nm h−1. Condensation of sulfuric acid and its subsequent neutralization by ammonia and coagulation contribute to the apparent particle growth on average 45±18% and 34±17%, respectively. The 30% higher concentration of sulfate than organic compounds in particles during the seven sulfur-rich NPF events but 20% lower concentration of sulfate during the five sulfur-poor type suggest that organic compounds are an important contributor to the growth of the freshly nucleated particles, especially during the sulfur-poor cases.