Design flaws in compact plants for wastewater treatment in food industry enterprises

The results of adjustment work, carried out at the local sewage treatment plants of food industry enterprise are presented in this paper. The enterprise has two sites, designed for the treatment of high and medium concentration effluents with a low pH value (3.5-5.5). Concentrated effluents are treated under anaerobic conditions in a compact installation consisting of a waste receiver, an anaerobic bioreactor, centrifuge thickener, centrifuge, flocculant preparation units and reagents. Wastes of medium concentration after neutralization are treated under aerobic conditions. The structure of this compact unit includes first-stage flotators, aerotanks operating for incomplete biological treatment, and second-stage flotators. Foam of the first stage and excess activated sludge of flotation devices of the second stage are dewatered on filter presses without treatment. The essence of the commissioning work consists in a detailed analysis of design solutions for both sites, study of the wastewater composition of high and medium concentration, systematization of operational data, which will allow operation to select the optimal operating mode of the main structures (anaerobic bioreactor and aeration tank). On the basis of the performed work, the optimal technological scheme of the unit for anaerobic digestion of high-concentration effluents has been developed and proposed. It is recommended to abandon the use of reagents, introduced before the flotation devices of the first and the second stages, due to an increase in the working pressure in the saturator for a compact installation designed for the treatment wastewater of medium concentration.

Biological evaluation of microcurrent wound dressing based on printed silver and zinc electrodes

Five types of silver/zinc (Ag/Zn) microcurrent dressings with different metal content were fabricated by screen printing and well-characterized by morphology, electricity and biological analysis in this study. Ag and Zn were printed alternately in a stripe pattern on the dressings’ surface. The metal particles adhered to the dressings sparsely, then densely, as the metal content increased gradually. The electrical test showed that with the increase of the metal content on the dressings, the current and voltage between positive and negative electrodes increased correspondingly. Hemolysis experiments demonstrated that the low to medium concentration of the metal would not cause hemolysis of red blood cells and had excellent blood compatibility. The results of coagulation experiments indicated that the coagulation performance within 10 min of the dressings was comparable with that of alginate dressing; in addition, the hemostatic performance was excellent. The cytotoxicity tests showed that the dressing A-C with low to medium concentration of the metal content, had no cytotoxicity, which followed the dose–effect relationship between the cytotoxicity and the metal content of the dressing. Furthermore, cell migration and mitochondrial membrane potential experiments indicated that microcurrent dressings altered mitochondrial membrane potentials of human foreskin fibroblast (HFF) cells while regulating cell migration. The stronger the current generated by the microcurrent base cloth, the more pronounced the migration effect of HFF cells becomes, and the higher the membrane potential of the fibroblasts within the acceptable threshold value range.

An Evidence for a Novel Antiviral Mechanism: Modulating Effects of Arg-Glc Maillard Reaction Products on the Phase Transition of Multilamellar Vesicles

Maillard reaction products (MRPs) of protein, amino acids, and reducing sugars from many foods and aqueous extracts of herbs are found to have various bioactivities, including antiviral effects. A hypothesis was proposed that their antiviral activity is due to the interaction with the cellular membrane. Aiming to estimate the possible actions of MRPs on phospholipid bilayers, the Arg-Glc MRPs were prepared by boiling the pre-mixed solution of arginine and glucose for 60 min at 100°C and then examined at a series of concentrations for their effects on the phase transition of MeDOPE multilamellar vesicles (MLVs), for the first time, by using differential scanning calorimetry (DSC) and temperature-resolved small-angle X-ray scattering (SAXS). Arg-Glc MRPs inhibited the lamellar gel–liquid crystal (Lβ-Lα), lamellar liquid crystal–cubic (Lα-QII), and lamellar liquid crystal–inverted hexagonal (Lα-HII) phase transitions at low concentration (molar ratio of lipid vs. MRPs was 100:1 or 100:2), but promoted all three transitions at medium concentration (100:5). At high concentration (10:1), the MRPs exhibited inhibitory effect again. The fusion peptide from simian immunodeficiency virus (SIV) induces membrane fusion by promoting the formation of a non-lamellar phase, e.g., cubic (QII) phase, and inhibiting the transition to HII. Arg-Glc MRPs, at low concentration, stabilized the lamellar structure of SIV peptide containing lipid bilayers, but facilitated the formation of non-lamellar phases at medium concentration (100:5). The concentration-dependent activity of MRPs upon lipid phase transition indiciates a potential role in modulating some membrane-related biological events, e.g., viral membrane fusion.

Extraction Recovery of Vanadium(V) by Amines

The extraction of vanadium (V) by N-(2-hydroxy-5-nonylbenzyl)-β, β- dihydroxyethylamine was studied depending on different factors, such as pH of the medium, concentration of extracting agent, temperature and solvent type. This allowed the optimal extraction conditions to be determined. It was shown that extraction of vanadium (V) takes place with high distribution coefficients, and a complex containing a decavanadate anion and four molecules of the extractant is formed in the organic phase. The extracted vanadium (V) complex with amine is stable for more than one month. Keywords: extraction, vanadium, distribution coefficient, infrared spectroscopy

Cell-to-Medium Concentration Ratio Overshoot in the Uptake of Statins by Human Hepatocytes in Suspension, but Not in Monolayer: Kinetic Analysis Suggesting a Partial Loss of Functional OATP1Bs

Suspended human hepatocytes (SHH) have long been used in assessing hepatic drug uptake, while plated human hepatocytes in short-term monolayer culture (PHH) have gained use in recent years. This study aimed to cross-evaluate SHH and PHH in measuring the hepatic uptake mediated by organic anion transporting polypeptide 1Bs (OATP1Bs). We compared the time courses of cell-to-medium (C/M) concentration ratios and initial uptake clearance values of the OATP1B substrates (pitavastatin, rosuvastatin, cerivastatin, pravastatin, dehydropravastatin, and SC-62807) between SHH and PHH. For all compounds except cerivastatin, the C/M ratios in SHH displayed an apparent overshoot (an initial increase followed by a decrease) during the 180-min uptake experiment, but not in PHH. Based on the literature evidence suggesting the possible internalization of OATP1Bs in primary hepatocytes, separate experiments measured the drug uptake after varying lengths of pre-incubation in the drug-free medium. The initial uptake clearances of pitavastatin and rosuvastatin declined in SHH beyond an apparent threshold time of 20-min drug-free pre-incubation, but not in PHH. Kinetic modeling quantitatively captured the decline in the active uptake clearance in SHH, and more than half of the active uptake clearances of pitavastatin and rosuvastatin were prone to loss during the 180-min uptake experiment. These results suggested a partial, time-delayed loss of the functional OATP1Bs in SHH upon prolonged incubation. Our results indicate that PHH is more appropriate for experiments where a prolonged incubation is required, such as estimation of unbound hepatocyte-to-medium concentration ratio (Kp,uu) at the steady-state.

Performance evaluation of a single mode optical fiber tip sensor for glucose detection

<p>Glucose must be carefully regulated to ensure its safety and quality. Nowadays, chemists often face difficulty to measure glucose concentrations as the current methods for the analysis are expensive and require complex procedures which have reduced the interest among chemists to use these techniques. This study evaluated the performance of a single mode optical fiber tip sensor for glucose detection. The sensing mechanism mainly depends on the Fresnel’s reflection that occurs at the flat fiber tip region while the sensor performance was evaluated based on its sensitivity and linearity. The sensor was tested in glucose solution at different concentration range; high range (0% - 14%), medium range (0% - 1.4%) and low range (0% - 0.14%). The sensor showed a good performance when sensing the glucose solution at high and medium concentration range with strong linearity of more than 90% and an average sensitivity of 0.0979 dBm/% and 0.1019 dBm/%, respectively. However, the low concentration range showed no significant changes during sensing. Based on the findings obtained in this study, the optical fiber tip sensor has the potential to be utilized for glucose detection and suitable for high and medium concentration range measurement.</p>