Heavy metals are taken up by the vascular plant root system from water solutions in cationic forms. Subsequently, during both short and long distance transport to other plant tissues, cation forms are incorporated to many bioorganic compounds differing in stability, ionic character and physico-chemical properties such as solubility in lipid structures and mobility across cell membrane systems. Many sequential and single step extraction methods have been elaborated for characterization of the role of individual components of plant cells components in transport and detoxication of heavy metals. In our study, dry biomass of giant reed (Arundo donax L.) grown in hydroponic media spiked with 65ZnCl2 and 109CdCl2 was treated with dithizone solutions as complexing ligand in order to convert free Zn2+ and Cd2+ ions to corresponding dithizonates. Treatment with dithizone showed that up to 67 % of the total plant Cd and 56 % of the total plant Zn were transformed to dithizonate complexes extracted with chloroform. Extraction of biomass with Folch reagent showed that up to 48 % of the total root cadmium and up to 18 % of the total shoot cadmium is bound in lipid fraction. Zinc was not found in lipid fraction of root and shoot. Derivatization of the dried root and shoot lipid fraction by dithizone showed that two third of Cd in root and practically all Cd in shoot lipid fraction could be transformed to Cd-dithizonate. Methods of biomass treating with complexing ligands and a method of sequential extraction procedures with non-polar organic solvents and radiotracer methodology seem to be useful methods for the study of metal speciation and distribution in vascular plants
Many organisms or their extracts have the ability to reduce Ag+ ions to Ag0 and stabilize them what results in nanoparticle formation in solution. The aim of the article was to study the influence of two selected parameters - initial silver concentration and culture age, on Ag nanoparticles production by green algae Parachlorella kessleri. The presence of Ag nanoparticles in the solution was confirmed by the UV-vis spectroscopy and TEM analyses. Typical curve with the peak at app. 420 nm was found for nanoparticles produced by algae. While culture age did not have any significant effect, the initial silver concentration had significant influence on nanoparticle production which influenced the rate of nanoparticle production, their amount, their size and stability, as well
The complete genomes of Enterococcus faecalis bacteriophages were analyzed for tetranucleotide words avoidance. Very similar tetranucleotide composition was found in all tested genomes with strong underrepresentation of palindromic GATC and GGCC words. This avoidance could be explained as a protection mechanism against host restriction-modification systems as a clear correlation was found between avoidance of palindromic words and the specificity of E. faecalis restriction and modification systems. No similar avoidance of tetranucleotide words was observed for non-palindromic words. A weak correlation was observed between avoidance of tetranucleotide palindromes in bacteriophage genomes and the possession of phage encoded DNA methyltransferases confirming the interrelation between bacteriophage genomes composition and restriction and modification systems in enterococci
Deposits of iron oxides in the human brain (globus pallidus) are visible under electron microscopy as object of regular and or/irregular shape but giving sharp diffraction patterns in the transmission mode. The SQUID magnetometry reveals that the magnetization curves decline form an ideal Langevin function due to the dominating diamagnetism of organic tissue. The fitting procedure yields the quantitative characteristics of the overall magnetization curves that were further processed by statistical multivariate methods
Gas chromatography and mass spectrometry (GC/MS) was applied for determination of concentrations volatile organic compounds present in human breath samples. The technique allows to rapid determination compounds in human air, at the level of parts per billion. It showed linear correlations ranging from 0.83-234.05 ppb, limit detection in the range of 0.31-0.75 ppb and precision, expressed as RSD, was less then 10.00%. Moreover, trained dogs are able to discriminate breath samples of patients with diagnosed cancer disease. We found positive correlation between dog indications and content of ethyl acetate and 2- pentanone in breath (r=0.85 and r=0.97, respectively)
Brown coal fly ash derived from the combustion of brown-coal in power plant ENO Nováky (Slovak Republic) was used as raw material for synthesis of zeolitic materials ZM1 and ZM3 by hydrothermal alternation with 1M NaOH and 3M NaOH, respectively. Fly ash and synthesized products were characterized using XRF and SEM-EDX analysis. Subsequently, zeolitic materials were tested as sorbents to remove Cs+ ions from aqueous solutions using radiotracer technique. Sorption of cesium by both types of zeolitic materials obeys Langmuir adsorption isotherm model. The maximum sorption capacities Qmax at pH 6.0 calculated from Langmuir isotherm were 1203 ± 65 μmol Cs+/ g for ZM1 and 1341 ± 66 μmol Cs+/ g for ZM3. The results showed that alkali treated fly ash can be used as effective sorbent for radiocesium removal from contaminated solutions
The aim of the present work is to characterize the soil additive derived from sewage sludge as potentially economically acceptable material for agricultural production as well as for soil and environment protection. The soil additive consisting of sewage sludge obtained from the wastewater treatment plant Pannon-Víz Zrt. (Győr, Hungary) and agricultural byproducts represented by wastes from grain mill industry and crushed corn cobs was prepared using the low-capacity granulator equipment constructed by Energy Agency Public Nonprofit Ltd. (Hungary). The characterization of sewage sludge as primary composite and prepared soil additive includes the determination of physico-chemical parameters such as pH determined in suspension with distilled water, 0.01 mol/dm3 CaCl2 or 1 mol/dm3 KCl solutions, pHzpc predicted by potentiometric titration and ProtoFit software, water holding capacity (WHC), cationexchange capacity (CEC) and total organic carbon (TOC). The elemental analysis by X-ray fluorescence spectrometry revealed that sewage sludge as well as prepared soil additive contain significant amount of Zn and Cu as important microelements in plant nutrition. Also, it was found that prepared soil additive represents the considerable source of a significant proportion, strong bound and in this way gradually released microelements. Obtained results suggest on the application potential of prepared soil additive in agricultural production as well as in remediation and reclamation of contaminated or degraded soil.
The Humulus lupulus L. is well known as necessary raw material for beer production. The main structural classes of chemical compounds identified from hop cones include terpenes, bitter acids, prenylated chalcones, and flavonol glycosides. They were subjects of presented work. The content of quercetin was found in the range 490 - 1092 μg/g and that of kaempferol from 218 to 568 μg/g of the dry hop cones. The content of isorhamnetin was very low in all varieties. From biological activities in vitro point of view, relative high level of inhibition activity was observed for six hop genotypes - Zlatan, Lučan, and the Oswald's clones 31, 70, 71, 72, 114 on both enzymes thrombin and urokinase, but without correlation to analyzed flavonols content. In spite of this, antioxidant activity, measured by both the BCLM and HPE methods, was found high and seem to be in correlation with content of analyzed flavonols. Particularly the Oswald's clone 114 expressed very potent biological activities. In general, obtained results indicate that hop cones are valuable material also for other application others than beer production.
Chromatographic columns with chiral stationary phases based on chemically - bonded derivatized cyclofructans were evaluated for HPLC enantioresolution of underivatized α-amino acids. The analytical study of chiral separation of these analytes was focused on the selection of suitable chiral stationary phase and mobile phase. Using isopropyl carbamate cyclofructan 6 as a chiral stationary phase, α- amino acid optical isomers were separated. The retention and enantioseparation of chiral amino acids were also influenced by a mobile phase composition. The mixture methanol/acetonitrile/acetic acid/triethylamine (75/25/0.3/0.2 v/v/v/v) was found to be the most effective mobile phase for HPLC separation of studied compounds. HPLC enantioresolution of chiral amino acids was thermodynamically studied. Based on the enthalpy and entropy contribution values calculated from the van´t Hoff equation, HPLC enantioseparation under chosen chromatographic conditions was found to be an enthalpically driven.
In this paper the thermodynamic analyses were used to calculate the contributions of entropic and enthalpic terms of the binding processes of selected derivatives of alkoxy-substituted phenylcarbamic acid (MEP) and phenolic acids (PAs) on the series of molecularly imprinted polymers (MIPs) and corresponding non-imprinted polymers (NIPs). All polymers were prepared by a bulk polymerization method with different porogens and functional monomers. The thermodynamic assessments were based on the quantification by HPLC measurements of the analytes tested in different mobile phases and at temperature range from 293 K to 333 K. The thermodynamic parameters were determined from the van’t Hoff plots - dependences between logarithms of the retention factors of studied analytes (ln k) and the inverse value of the temperature (1/T). Almost all data showed that enthalpic term was the dominating driving force for the investigated analytes.