Effect of Sodium Metabisulfite on Selective Flotation of Chalcopyrite and Molybdenite

Sodium metabisulfite (MBS) was used in this study for selective flotation of chalcopyrite and molybdenite. Microflotation tests of single and mixed minerals were performed to assess the floatability of chalcopyrite and molybdenite. The results of microflotation of single minerals showed that MBS treatment significantly depressed the floatability of chalcopyrite and slightly reduced the floatability of molybdenite. The results of microflotation of mixed minerals demonstrated that the MBS treatment could be used as a selective chalcopyrite depressant in the selective flotation of chalcopyrite and molybdenite. Furthermore, the addition of diesel oil or kerosene could significantly improve the separation efficiency of selective flotation of chalcopyrite and molybdenite using MBS treatment. A mechanism based on X-ray photoelectron spectroscopy analysis results is proposed in this study to explain the selective depressing effect of MBS on the flotation of chalcopyrite and molybdenite.

Possibilities of recombinant cytokines in the structure of training of highly qualified athletes

Serious sports achievements are associated with extreme impacts on the human body: psycho-emotional and physical loads of the training period, competitions requiring the mobilization of all the adaptive reserves of the body, changes in climatic conditions when athletes move long distances, adverse environmental factors leading to hypothermia. The combination of these factors has a depressing effect on the immune system. The emergence of immune disorders in athletes during periods of extreme physical and psycho-emotional stress made it possible to identify the mechanisms of adaptation failure and depletion of immunity reserves, which requires corrective measures. Roncoleukin® is a complete structural and functional analogue of endogenous interleukin-2 (IL-2) and has the same spectrum of functional activity. It is able to compensate for the deficiency of IL-2 and reproduce its effects as one of the key components of the cytokine network.

Geranyl-geraniol addition affects potency of bisphosphonates—a comparison in vitro promising a therapeutic approach for bisphosphonate-associated osteonecrosis of the jaw and oral wound healing

Purpose Analysis of the influence of geranyl-geraniol (GG) addition on four bisphosphonate derivatives regarding their influence on cell viability and migration ability of bone metabolism and endothelial cells in vitro. Methods Clodronate, pamidronate, ibandronate, and zoledronate were observed with and without GG addition, for their effect on human osteoblasts (HOB), normal human dermal fibroblasts (NHDF), human endothelial progenitor cells (EPC), and endothelial cells of the human umbilical cord (HUVEC) using migration-, MTT-, and colony-forming cell assays. Results Data pointed to a depressing effect of all bisphosphonates on the migration ability of NHDF, EPC, and HOB. MTT assay demonstrated a decreased cell viability of HUVEC of all bisphosphonates in a 50 μM concentration and of NHDF when treated with 50 μM of clodronate, ibandronate, or zoledronate. Tested drugs showed a depressing effect on colony-forming potential of EPC even in a 5 μM concentration. GG addition demonstrated an attenuate impact on bisphosphonate effect on all primary cell cultures, respectively. Conclusion In vitro comparison showed that the addition of GG weakens the effect of all bisphosphonates examined. It supports investigations that suggest GG to be able to prevent bisphosphonate-associated osteonecrosis of the jaw (BP-ONJ) in vivo. Future clinical trials may discover the local therapeutic use of GG for the prevention of BP-ONJ.

INFLUENCE OF NATURAL FACTORS ON THE NUMBER OF IXODIC TICKS OF THE GENUS DERMACENTOR IN TYUMEN REGION

At present, the ixodofauna of the Tyumen region is represented by six species of ixodid ticks – these are Ixodes persulcatus Schulze, 1930; Dermacentor reticulatus Fabricius, 1794 (D. pictus, Hermann, 1804); D. marginatus Sulz, 1776; I. apronophorus P. Sch., 1924; I. (Exopalpiger) trianguliceps Bir., 1895 and I. (Ceratixodes) plumbeus, Kirsch., 1936. Three species of ixodid ticks parasitize cattle: I. persulcatus, D. reticulatus, D. marginatus. The remaining three species of ticks, Ixodes apronophorus, Ixodes strianguliceps, and Ixodes plumbeus, belong to the nest-like parasitic type and therefore are less dangerous parasites for large mammals. The most widespread ticks of the genus Ixodes and Dermacentor in the context of all natural-geographical zones of the region are ticks of the genus Dermacentor, their dominance index was 54.8%. As a result of observation, it was noted that the temperature and humidity of the air affect the activity of ixodid ticks of the genus Dermacentor in nature. Thus, the peak of ixodid activity in the spring period fell on days when the air temperature reached values from 16 oC to 26 oC, and in autumn from 15 oC to 21 oC, while lower and higher humidity indices had a depressing effect on ixodid mites of the genus Dermacentor.

Chalcopyrite and Molybdenite Flotation in Seawater: The Use of Inorganic Dispersants to Reduce the Depressing Effects of Micas

The objective of this work was to study the effect of muscovite and biotite on the flotation of chalcopyrite and molybdenite in seawater, and the use of sodium hexametaphosphate and sodium silicate to improve copper and molybdenum recoveries. The impact of the inorganic dispersants on the settling properties of the resulting flotation tailings was also studied. It was found that muscovite and biotite depress the flotation of chalcopyrite and molybdenite in seawater, with this depressing effect being stronger at pH 11 than at pH 9. Sodium hexametaphosphate and sodium silicate increased the recoveries of copper and molybdenum in seawater. These dispersants render the mineral particles more negatively charged and remove the hydroxy-complexes of magnesium and calcium from the mineral particles causing dispersion of the slimes. The settling rates of the flotation tailings slightly decrease when sodium hexametaphosphate and sodium silicate were added in the flotation stage. The presence of ultrafine particles dispersed by the action of the inorganic dispersants negatively impacted the flocculation and sedimentation processes leading to high flocculant consumption, low settling rates and high turbidity of the supernatant.

The use of marine microalgae for biotesting the waters of Sevastopol bays

For biotesting the marine environment, multicellular organisms are often used, primarily fish and their embryos. However, microalgae are still not used sufficiently enough for this purpose, the number of tested species is extremely limited. The aim of this work was to study the response of three species of planktonic microalgae to the complex pollution of the Black Sea coastal waters in the Sevastopol region and to assess the possibility of their application for biotesting. The studies were carried out on the diatom Phaeodactylum tricornutum and two dinoflagellates Prorocentrum cordatum and Gyrodinium fissum. To characterize the level of pollution of surface waters with organic substances, two indicators were used: BOС5 (biological oxygen consumption) and permanganate oxidizability. Evaluation of the effect of the water sample pollution on microalgae was carried out by the comparison between the coefficient of increase in the abundance of microalgae cells (Xk) in the experiment and the control one. Laboratory experiments carried out in the summer and autumn periods made it possible to reveal, in most cases, a weak depressing effect of the studied waters pollution on the microalgae growth. Occasionally, this effect reached a chronic level. In the summer period (in June), a stimulating effect of water pollution on the growth of dinoflagellates was observed, reaching the level of subacute level in 50% of cases. The necessity of using several types of microalgae of different taxonomic affiliation when performing biotesting of sea waters is highlighted.

Fungicidal and antistress properties of the preparation based on triterpene acids on spring barley

The most effective concentration range of the studied preparation synthesized on the basis of triterpene acids is in the range of 0.01-0.005 %. In the conditions of water-salt stress, the studied preparation increased laboratory germination of seeds, length of seedling and root of spring barley compared with the control variant. At a concentration of 0.01-0.005 %, the preparation reduced the intensity of the pathogenic complex development on the seed material of spring barley, but was significantly inferior in effectiveness to the synthetic protectant. At the same time, unlike a fungicide, the preparation did not have a depressing effect on the development of barley in the initial stages of ontogenesis.

Molybdenite Flotation in the Presence of a Polyacrylamide of Low Anionicity Subjected to Different Conditions of Mechanical Shearing

Polyacrylamides (PAM) are used as flocculants in the copper-molybdenum mining industry to improve the settling rate of flotation tailings. These types of reagents are recirculated to flotation in the water that is recovered from the thickeners, and as a result of this practice they can cause depression of flotation of some important minerals such as molybdenite. The objective of this work was to study the effect of a PAM of 11.9% of degree of anionicity on the flotation of molybdenite. The effect of the anionic PAM on molybdenite flotation was studied under different levels (three) of flocculant mechanical shearing. The flotation data was discussed along with intrinsic viscosity, adsorption, induction time, and electrophoretic mobility measurements. It was found that the non-sheared PAM (NS–PAM) had the strongest depressing effect on molybdenite flotation, followed by the moderately sheared PAM (MS–PAM). The depressing effect of the strongly sheared PAM (SS–PAM) was negligible. The flotation data correlated with the induction time measurements that showed that molybdenite became more hydrophilic in the presence of the NS–PAM. The SS–PAM has no effect on the induction times. Further work is ongoing to understand the effect of PAM on molybdenite flotation in the presence of clay minerals and different aqueous media.

Effect of Mixed Commercial Cold Flow Improvers on Flow Properties of Biodiesel from Waste Cooking Oil

The uniform design method was used to screen the solidifying point depressing effects of 18 traditional diesel cold flow improvers on biodiesel derived from waste cooking oil. The cold flow improvers with good effects were selected for orthogonal optimization. Finally, the mixed cold flow improver (CFI) with the best depressing effect was selected to explore its depressing mechanism for biodiesel. The results show that the typical CFIs such as A132, A146, 10-320, 10-330, A-4, CS-1, AH-BSFH, Haote, T1804D, and HL21 all have a certain solidifying point depressing effect on biodiesel, while other cold flow improvers had no obvious effect. Amongst them, 10-330 (PMA polymer) and AH-BSFH (EVA polymer) had better solidifying point depressing effects over others, both of which reduced the solidifying point (SP) of biodiesel by 4 °C and the cold filter plugging point (CFPP) by 2 °C and 3 °C, respectively. From the orthogonal mixing experiment, it can be seen that the combination of 10-330 and AH-BSFH at a mass ratio of 1:8 had the best depressing effect, reducing the solidifying point and cold filter plugging point of biodiesel by 5 °C and 3 °C, respectively. Orthogonal analysis showed that when used in combination, AH-BSFH had a greater impact on the solidifying point, while the ratio of the combination had a greater impact on the cold filter plugging point.