Dynamics of exposure to mercury in a population of the upper Madeira River, Rondônia – Brazil

This work evaluates the influence of cognitive and sociodemographic functions on the dynamics of human exposure to mercury in communities on the upper Madeira River in the state of Rondônia, Brazil. In this longitudinal epidemiological study of convenience sampling (2009 to 2019), semi-structured questionnaires on cognitive and sociodemographic aspects were applied to 1,089 participants (646 men and 443 women) divided into 6 groups with distinct geographic characteristics and lifestyles. Total mercury concentrations in hair samples were determined by direct analysis using atomic spectroscopy. In this population, cognitive (memory, attention span, concentration and difficulties in reading, writing and mathematical calculations) and sociodemographic (location, gender, age, education, alcohol consumption, smoking habits, time of residence in the region, occupation) grouping showed the differentiation between the groups with lifestyle directly related and dependent on extractivism/gold mining dispersed along the Madeira River (G1 and G2), and the groups that have urban dynamics on the margins of the federal highway BR-364 (G3, G4, G5 and G6). Sex, age and lifestyle (groups) were significant indicators of total mercury concentrations in hair. The organization of participants according to cognitive and sociodemographic profiles, regardless of geographic location, highlights the contribution of individualized social dynamics to mercury exposure in the Madeira River basin region. Despite socio-historical and socio-economic similarities, cognitive and sociodemographic functions show individualized social behaviors within communities, which may influence the process of exposure to THg.

Comparative analysis of the content of heavy metals in raw materials of some representatives of the genus Paeonia L.

Currently, heavy metals are considered as priority soil pollutants. It is known that the vegetative mass of agricultural crops is capable of accumulating them in large quantities. Ornamental flower crops, which firmly occupy their ecological niche, are practically not considered from this point of view. The aim of this work is to study the features of the accumulation of heavy metals in the aboveground and underground organs of some representatives of the genus Paeonia L. in the urbanized environment of the city of Ufa. The objects of research were seven taxa of Paeonia (P. peregrina Mill., P. lactiflora Pall., P. lactiflora f. rosea, P. delavayi Franch., P. × hybrida Appassionata, Mustai Karim, Jeanne d’Arc). Methodology. The study of the elemental composition of the aboveground and underground parts was carried out according to the method No. M-02-1009-05 atomic spectroscopy. Mathematical data processing was carried out using generally accepted methods of variation statistics using the AgCStat software package in the form of an Excel add-in. Scientific novelty. For the first time, different taxa and parts of Paeonia plants were taken for research. Results. It was revealed that in the studied samples the copper content is 4,15–2520,00 times higher than that of other elements. It is noted that the minimum concentrations of arsenic, cadmium, chromium, manganese and iron are noted in the roots; lead and nickel – in flowers; copper – in the leaves of the studied paeonies. The maximum content of arsenic, lead, chromium is found in the leaves; cadmium, nickel, manganese – in the stems; iron – in flowers. That is, cutting paeonies in the autumn before retirement avoids the accumulation of these microelements in the soil. The results of the correlation analysis showed that the absolute values of the concentrations of the studied elements in the considered taxa of paeonies correlate with each other to a weak and medium degree. Correlation study of pairs of elements makes it possible to assess the synergism of accumulation and its absence, which is consistent with the opinion of other authors.

APPLICATION OF ATOMIC SPECTROSCOPY TO MEASURING STRONG INHOMOGENEOUS MAGNETIC FIELDS

Using the spectrum of selective reflection (SR) of laser radiation from the boundary of the surface of the dielectric window of the spectroscopic nanocells – pairs of rubidium atoms, the value of the magnetic field applied to the nanocell is measured. A method is proposed for calculating the magnetic induction B in the range of 0.1–6.0 kG based on the ratio of the frequency intervals between atomic transitions, which greatly simplifies the determination of B, particularly, there is no need for a reference spectrum at B = 0. To implement the SR process a 300-nm column of vapors of Rb atoms is used, and atomic transitions with a sub- Doppler spectral width of 80–90 MHz are formed. This leads to frequency separation of transitions in SR spectrum that is important for the proposed method. SR spectrum can be analyzed using a specially designed computer program that accelerates the data processing. The small thickness of the vapor column allows high spatial resolution, which is important in the case of inhomogeneous magnetic fields.

Biological Equivalence of GGTA-1 Glycosyltransferase Knockout and Standard Porcine Pericardial Tissue Using 90-Day Mitral Valve Implantation in Adolescent Sheep

Objective There is growing interest in the application of genetically engineered reduced antigenicity animal tissue for manufacture of bioprosthetic heart valves (BHVs) to reduce antibody induced tissue calcification and accelerated structural valve degeneration (SVD). This study tested biological equivalence of valves made from Gal-knockout (GalKO) and standard porcine pericardium after 90-day mitral valve implantation in sheep. Methods GalKO (n = 5) and standard (n = 5) porcine pericardial BHVs were implanted in a randomized and blind fashion into sheep for 90-days. Valve haemodynamic function was measured at 30-day intervals. After explantation, valves were examined for pannus, vegetation, inflammation, thrombus, and tissue calcification. Results Nine of 10 recipients completed the study. There was no difference between study groups for haemodynamic performance and no adverse valve-related events. Explanted BHVs showed mild pannus integration and minimal thrombus, with no difference between the groups. Limited focal mineral deposits were detected by x-ray. Atomic spectroscopy analysis detected tissue calcium levels of 1.0 µg/mg ± 0.2 for GalKO BHVs and 1.9 µg/mg ± 0.9 for standard tissue BHVs (p = 0.4), considered to be both low and equivalent. Conclusions This is the first demonstration of biological equivalence between GalKO and standard pig pericardium. The GalKO mutation causes neither intrinsic detrimental biological nor functional impact on BHV performance. Commercial adaptation of GalKO tissue for surgical or transcatheter BHVs would remove the clinical disparity between patients producing anti-Gal antibody and BHVs containing the Gal antigen. GalKO BHVs may reduce accelerated tissue calcification and SVD, enhancing patient choices, especially for younger patients. Graphical Abstract

Synthesis, Characterization and Thermogravimetric Study of Some Metal Complexes of Selenazone Ligand Nanoparticles Analogue of Dithizone

A new method for preparing 1,5-diphenylselenocarbazone (selenazone) nanoparticles and their complexes with Pb2+, Cd2+, Co2+, and Ni2+ has been performed using hot methanol solvent. The ligand and its complexes were characterized using FT-IR, UV-Vis, 1H-NMR, 13C-NMR, X-ray powder diffraction (XRD), EI-mass spectrometry, scanning electron microscopy (SEM), HG and flame-atomic absorption spectrophotometer, thermal analysis (TG/DTA), and molar conductance measurements. The molar conductance measurements in all complexes were recorded low values in DMSO, indicating that all the metal complexes were non-electrolytes except the nickel complex that possessed an electrolytic nature. Kinetic and thermodynamic parameters of complexes (A, E, ∆H, ∆S, and ∆G) have been computed using three kinetic models of Coast-Redfern, Broido, and Horowitz-Metzger, that illustrated the decomposition reactions in all steps were nonspontaneous. Thermogravimetric analyses (TG/DTA) were consistent with the atomic spectroscopy data proving that the geometry shape of all the complexes was octahedral.

Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)

Recommendations are given concerning the terminology of concepts and methods used in spectroscopy in analytical chemistry, covering nuclear magnetic resonance spectroscopy, atomic spectroscopy, and vibrational spectroscopy.