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[en] Cupriavidus SRS is a metal resistant, rod shaped, gram negative bacteria that was isolated from a location with heavy metal contamination at the Department of Energy’s Savannah River Site in Aiken, South Carolina. This isolate has also been able to demonstrate antibiotic resistance and predatory behavior to other microorganisms, giving it a competitive advantage. The effect of bioaugmentation with Cupriavidus SRS and copper (Cu) uptake is not well understood, although multiple studies have analyzed this effect with other metal resistant bacteria. In this study, sediment from the AL1 outfall area will be inoculated with Cupriavidus SRS to analyze the effectiveness of the degradation of Cu.
[en] One of the perspective directions for the restoration of contaminated lands is the use of humic-based compounds. The structure of these types of compounds causes to form compounds that dissolve in water combining heavy metals, radionuclides, pesticides and other toxicants. The use of humic-based compounds causes to the land clearing and causes to the increasing of its productivity. During experiments it has been determined that humates have more effective impact with the form of enriched microelements.
[en] Mitochondria are cellular powerhouses as well as metabolic and signaling hubs regulating diverse cellular functions, from basic physiology to phenotypic fate determination. It is widely accepted that reactive oxygen species (ROS) generated in mitochondria participate in the regulation of cellular signaling, and that some mitochondria chronically operate at a high ROS baseline. However, it is not completely understood how mitochondria adapt to persistently high ROS states and to environmental stressors that disturb the redox balance. Here we will review some of the current concepts regarding how mitochondria resist oxidative damage, how they are replaced when excessive oxidative damage compromises function, and the effect of environmental toxicants (i.e. heavy metals) on the regulation of mitochondrial ROS (mtROS) production and subsequent impact.
[en] The comprehensive sensory, analytic-chemical, physical-chemical and microbiological analyzes of numerous water samples taken from upper and lower layers of the largest rivers of Azerbaijan - Kur and Araz were carried out. Sources of the anthropogenic emissions polluting these cross-border rivers are defined. The dose rate of ionizing radiation in nearby territories along the watercourse of these rivers and on minerals of water samples was measured and the levels of all types of ionizing radiation were estimated.
[en] Specific activities were measured along a sediment profile collected nearby to the Yara River mouth at the Guacanayabo Gulf. X-Ray fluorescence was also used to measure K, Ca, Ti, Fe, Mn, Cu, Ni, Co, Pb and Zn in this profile and in surface samples along the coastline near of estuary Yara. The measurement of the specific activities evidenced strong mixture process, Heavy metal concentrations have similar values along the profile, excepting Pb that has the greatest values at the surface. All the samples have different pollution levels mainly of Zn, Pb, Cu and Co elements. With the calculated index (Geo-accumulation (Igeo) and Enrichment Factor (EF) index) this coastal environment can be classified as unpolluted to moderately pollute. According to the NOOA indicators, bay levels of before mentioned metals, mainly Cu and Co, were considered as potentially toxic, therefore, further investigations are strongly recommended. An increase in the level of pollutants was evidenced in relation to previous study performed in 2008. The obtained results have shown the influence of the sewer city system, which collects spills of several activities, agricultural use of metal-containing fertilizers and pesticides, and the emission of untreated sewage and also metal contaminated effluents from medical use and industrial units. (Author)
[en] Interspecies, inter-tissue and interspatial dissimilarities of trace metals in particular body parts of Saccostrea cucullata, Thais clavigera and Nerita chameleon from the east Johor coastal waters were compared. Metals of interest includes Pb, Cd, Zn, Cu, Mn, Co, Se and Sr. Bivalve mollusk S. cucullata evidenced to be a worthy bioindicator for Zn and Cu while the two gastropod molluscs, T. clavigera for Cd and Se, and N. chameleon for Pb, Mn and Sr. The prominent concentration of metals originate in T. clavigera may be the outcome of biomagnification transfer from the S. cucullata on which they feed while for N. chameleon, it might be resulting from their herbivorous feeding behavior on algae on rocks which they graze. The metal accumulation patterns indicate consistent enrichment of essential metals in soft tissue. Values of operculum to tissue ratio (OTR) and shell to tissue (STR) higher than unity in T. clavigera indicate that operculum had higher affinities for Pb, Mn and Se while shell had higher affinities for Co and Sr. In N. chameleon, values of OTR and STR higher than unity displayed that operculum and shell had similar higher affinities for Co and Sr and Cd, Co and Sr, respectively. Significant interspatial variations (p<0.05 and p<0.01) in trace metals were noted. Assessment of metal concentration with maximum permissible limits of toxic metals in food shown the values were well within safety levels, except for Zn in S. cucullata that need to be monitored. (author)
[en] YbNiP is a stoichiometric heavy-fermion Kondo-lattice system with a Kondo temperature of 8 K 1. This system is situated in the close vicinity of a ferromagnetic (FM) quantum-critical point (QCP) and can be tuned to the FM QCP by substituting a small amount of phosphorous by arsenic 1. Recently, nine field-induced Lifshitz transitions (LTs) have been proposed in YbNiP 2 from the results of the transport and thermodynamic measurements, revealing a complicated electronic band structure of the system. We have performed ultrasonic measurements on single crystals of YbNiP to deepen the understanding of these phase transitions. We found clear features in the ultrasound velocity (v) and the attenuation () corresponding to crystal-electric-field and Kondo effects. However, we detected no or very small anomalies in v or at the expected FM phase transition in the longitudinal c33 mode, reflecting a weak coupling of the corresponding symmetry strain to the magnetic structure. On the other hand, pronounced features were identified at the proposed Lifshitz transitions at roughly 0.4, 6 and 7 T clearly demonstrating the different character of these transitions.
[en] The abandoned mining area is known to contain high concentration of heavy metals and radionuclides that can be harmful to human and the ecosystem itself. Mussel families are commonly used as bio monitoring tools to monitor the environmental pollution. Therefore, Ligumia recta (Black Sandshell), locally known as kijing was used to act as biological indicators that help in monitoring the heavy metals and radionuclides level. This study was carried out in Kampung Gajah, Perak which known as ex-mining area. The objective of this study is to determine the concentrations of As, Cd, Pb, Hg, "2"3"8U, "2"3"2Th and "4"0K in Ligumia recta collected from two ex-mining lakes; Tasik Kapal Tujuh and Tasik Air Hitam. The samples were divided into three categories based on size. The flesh were separated from the shell, oven dried, ground, sieved and pelletizing before measured using Energy Dispersive X-Ray Fluorescence Spectrometer (EDXRF). The results show that the concentrations of heavy metals and radionuclides in the two lakes have significant differences, however there are no significant differences between the size of the samples (p>0.05). In addition, the concentrations were found to be higher at Tasik Kapal Tujuh compared to Tasik Air Hitam. This may be due to the size of the lakes and the acidity of water in the lakes. From the concentrations of the heavy metals and radionuclides, the exposure ingestion dose rate, health risk index (HRI) and radiological health risk were calculated to monitor the safety level in the Ligumia recta for human consumption. (author)
[en] The measurement of diffusion coefficients of bentonite is normally very time-consuming. Moreover, bentonite is a mixture of different minerals. Some of such impurities can even react with the target heavy metals for diffusion coefficient determination. The more the impurities in the bentonite, the longer will be retarded for the through-diffusion to reach steady state. To overcome this problem, a new method was developed by saturating the sample with target heavy metals in very low concentration before the through-diffusion experiment (TDE). Comparison experiments of through-diffusion were conducted with traditional and the new methods, it appears that the experimental duration with the new TDE is largely shortened. Further experiments were conducted for Cd and Cs elements, it is shown that the new method of through-diffusion experiment can be used to efficiently determine the long-term diffusion coefficient of heavy metals
[en] Chromium pollution is a problem that affects different areas worldwide and, therefore, must be solved. Bioremediation is a promising alternative to treat environmental contamination, but finding bacterial strains able to tolerate and remove different contaminants is a major challenge, since most co-polluted sites contain mixtures of organic and inorganic substances. In the present work, Bacillus sp. SFC 500-1E, isolated from the bacterial consortium SFC 500-1 native to tannery sediments, showed tolerance to various concentrations of different phenolic compounds and heavy metals, such as Cr(VI). This strain was able to efficiently remove Cr(VI), even in the presence of phenol. The detection of the chrA gene suggested that Cr(VI) extrusion could be a mechanism that allowed this strain to tolerate the heavy metal. However, reduction through cytosolic NADH-dependent chromate reductases may be the main mechanism involved in the remediation. The information provided in this study about the mechanisms through which Bacillus sp. SFC 500-1E removes Cr(VI) should be taken into account for the future application of this strain as a possible candidate to remediate contaminated environments.