Metal Profiles Research Articles

Effects of farmland abandonment on anthropogenic-alluvial soil microbiota and contaminant residues in Lycium barbarum fields.

There has been an increasing tendency to abandon crop cultivation and farming in old Lycium barbarum (wolfberry) stands to allow for natural restoration. However, little research has been dedicated to deciphering how soil quality changes in L. barbarum fields following abandonment from a physicochemical and microbiological perspective. Here we assessed the effects of farmland abandonment on anthropogenic-alluvial soil microbiota and contaminant residues in L. barbarum fields in Ningxia, China. Soil microbiota, heavy metal, and neonicotinoid pesticide profiles in L. barbarum fields abandoned for one to four years were characterized. Microbial community analysis was performed by high-throughput sequencing of the bacterial 16S ribosomal RNA genes and the fungal nuclear ribosomal internal transcribed spacer region. Soil bacterial diversity increased from before abandonment to year three after abandonment, and fungal diversity peaked in year one after abandonment. Enrichment of potentially beneficial taxa (e.g. Limnobacter, Cavicella) as well as pathogenic taxa (e.g. Ilyonectria) was observed in the abandoned field soils, along with depletion of other taxa (e.g. Planococcus, Bipolaris). Soil copper, zinc, cadmium, imidacloprid, and acetamiprid concentrations all decreased with increasing time since abandonment and had varied correlations with soil quality, microbial diversity, and the relative abundances of major phyla. Soil available phosphorus, nitrate-nitrogen, and pH were the key factors shaping bacterial communities. The structuring of fungal communities was strongly influenced by soil pH, available phosphorus, and available nitrogen contents. There were positive consequences of farmland abandonment in L. barbarum fields, such as optimized microbial community structure, reduced heavy metal accumulation, and enhanced pesticide degradation.

Weathering alters the profile of trace metals and organic compounds in leachates and bioavailability extracts from microplastics of trail running shoes

Microplastics (MPs) from rubber outsoles of trail running shoes may contribute significantly to contamination in protected areas. In the natural environment, weathering processes can damage MP molecular structure and alter the mobility of inorganic and organic compounds used as additives in rubber. In this study, we characterised changes in the surface morphology, functional groups, and thermal stability of MPs weathered on and below the soil surface over 12 weeks, and analysed inorganic and organic additives in leachates (0.01M CaCl2) and bioaccessibility extracts (ethyl acetate). Weathering conditions included UVC irradiation at 25 °C and 80% soil moisture. Microplastics on the soil surface exhibited cracking, fragmentation, and increased extractability of zinc, sulphur, titanium and fatty acids. Microplastics below the soil surface were not significantly physically or chemically altered, however zinc leachability increased following extended weathering by up to 155%. Bioaccessibility of thiol, aromatic and cyclic organic additives decreased from both surface and sub-surface MPs over the 12 week weathering period, but there was evidence of an increase in transformation by-products. Microplastic toxicity may be significantly altered by environmental conditions and MP weathering. It is critical ecotoxicological studies use weathered MPs to assess impacts on rare and endemic species found in protected spaces.

CATION COMPOSITION OF ORAL SECRETION IN PRIMARY SCHOOL-AGED CHILDREN

SUMMARY. Recurrent respiratory infections (RRIs) currently have the greatest medical and social burden among infectious diseases worldwide, with the highest prevalence and incidence rates of acute respiratory infections in children. Recent studies indicate the role of inadequate immune response and the development of recurrent acute respiratory infections (ARI) in children due to deficiencies in essential trace elements in the body, which are crucial for the proper functioning of physical barriers and the immune system. The hypothesis of our study assumed that, considering the recurrence of at least 6 episodes of ARI per year, children with RRIs may have changes in salivary ion levels, which could serve as a basis for local immune suppression of the upper respiratory mucosa. The aim – to investigate the levels of metals in the saliva of children of primary school age with recurrent respiratory infections in comparison with episodically ill peers and establish the relationship of these changes with the state of local immunity. Material and Methods. In the actual study, 40 children participated, with 30 of them (the main group) being children with recurrent respiratory infections and 10 other children who had episodic illnesses were assigned to the control group. The levels of metal cations in the saliva were examined using inductively coupled plasma atomic emission spectrometry, including essential metals such as copper, manganese, zinc, calcium, cobalt, potassium, magnesium, sodium, phosphorus, selenium, iron, chromium, and sulfur. Additionally, levels of conditionally essential metals like lithium, nickel, and boron were measured. The levels of secretory IgA and lysozyme in saliva were determined using the enzyme-linked immunosorbent assay method. Results. The main group was not homogeneous; therefore, we divided it into two clusters. Respondents in one cluster had significantly lower relative levels of essential ion content in saliva. Specifically, calcium was lower in 64 % (p=0.003), copper in 76.5 % (p=0.001), manganese in 41.1 % (p=0.008), magnesium in 64 % (p=0.02), and zinc in 58.8 % (p=0.027). This fact can be explained by their increased losses due to frequent inflammatory processes in the upper respiratory tract, resulting in higher daily replenishment needs compared to their peers. Correlation analysis revealed a connection between illness incidence and the levels of copper (p=0.008), sodium (p=0.00005), and phosphorus (p=0.028), indicating potential associations between saliva metal profiles and the frequency of ARI in children with RRIs. The presence of dental caries correlated with lithium (p=0.02), copper (p=0.032), and nickel levels (p=0.037). Integral indicators of local immunity, such as lysozyme and secretory IgA, exhibited correlations with metal levels in saliva (Li, Cu, Ni, Na, Co, P, Zn), confirming the hypothesis of their role in regulating immune reactions in the oral cavity. Conclusions. Cluster analysis of the metal profiles of the group of children with RRI shows its heterogeneity, 43 % of representatives of this cohort had significantly lower levels of calcium (p=0.003), copper (p=0.001), manganese (p=0.008), magnesium (p=0.02) and zinc (p=0.027) than the control group. Which may indicate the presence of deficient conditions in some children with PRI as a result of the increased need for their recovery. The presence of caries, the level of SIgA, lysozyme (clinical indicators of local immunity of the oral cavity) have certain relationships with the levels of essential and conditionally essential levels of salivary metals (Li, Cu, Ni, Na, Co, P, Zn), which indicates the benefit of the connection between the metal profile of saliva and the state of local immunity.

Green Turtle (Chelonia mydas) Blood and Scute Trace Element Concentrations in the Northern Great Barrier Reef.

Marine turtles face numerous anthropogenic threats, including that of chemical contaminant exposure. The ecotoxicological impact of toxic metals is a global issue facing Chelonia mydas in coastal sites. Local investigation of C. mydas short-term blood metal profiles is an emerging field, while little research has been conducted on scute metal loads as potential indicators of long-term exposure. The aim of the present study was to investigate and describe C. mydas blood and scute metal profiles in coastal and offshore populations of the Great Barrier Reef. This was achieved by analyzing blood and scute material sampled from local C. mydas populations in five field sites, for a suite of ecologically relevant metals. By applying principal component analysis and comparing coastal sample data with those of reference intervals derived from the control site, insight was gleaned on local metal profiles of each population. Blood metal concentrations in turtles from coastal sites were typically elevated when compared with levels recorded in the offshore control population (Howick Island Group). Scute metal profiles were similar in Cockle Bay, Upstart Bay, and Edgecumbe Bay, all of which were distinct from that of Toolakea. Some elements were reported at similar concentrations in blood and scutes, but most were higher in scute samples, indicative of temporal accumulation. Coastal C. mydas populations may be at risk of toxic effects from metals such as Co, which was consistently found to be at concentrations magnitudes above region-specific reference intervals. Environ Toxicol Chem 2023;42:2375-2388. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Antimicrobial, Physicochemical, Proximate and Heavy Metal Profiles of Selected Honey Samples from two Southwestern States in Nigeria

Honey is made up of a variety of sugars, minerals, vitamins, enzymes, proteins, phenolic mixtures, and organic components, which define if the honey is genuine or contaminated. As a result, this work was undertaken to examine the nutritional and heavy metal properties of honeys sold in two Nigerian states in the South west. Samples of honey were taken from twenty hives in two southwestern states and tested for antimicrobial, physicochemical, proximate, and heavy metal characteristics using standard recommended procedures, while heavy metals were detected with an Atomic Absorption Spectrophotometer. Zones of inhibition at 100 % w/v for the test organisms are 10 – 28 mm for E. coli, 13 – 26 mm for Salmonella, 17 – 27 mm for Staphylococcus aureus, and 11 – 25 mm for Klebsiella with S. aureus being more sensitive to the honey samples. The range of pH for physicochemical is 2.51 – 3.87, Total Titratable Acidity 0.07 – 0.53 percent, Acidity 1.20 – 6.77 %, and the ranges for proximate analyses are 1.09 – 1.59 % protein, 7.10 – 11.37 % moisture, 0.33 – 0.63 % Ash, 0.20 – 0.30 % fat, 83.71 – 91.11 % carbohydrate, and 342.95 – 371.20 kcal/g energy. There was significant correlation recorded between protein, moisture, ash, fat, carbohydrate and energy contents of the honey samples. All the honey samples were negative for lead, chromium, and cadmium. Copper was the only metal found, having concentrations range of 5.0 to 25.0 mg/kg. Because the majority of the samples fulfilled the Codex Alimentarius Standard for honey, they can be taken or used therapeutically.

Different pollution levels and source profiles of heavy metals in the soil and surface dust of children's playgrounds in a coastal city; source-specific health risk assessment

This study compared the pollution levels, health risks, and sources of heavy metals (HMs) in the dust accumulated on the play equipment and the soil of children's playgrounds located in a humid subtropical city (Bandar Abbas, Iran). Therefore, a total of 74 samples of soil and equipment dust were collected from 37 children's playgrounds and the concentrations of HMs were analyzed by Inductively Coupled Plasma Optical Emission spectroscopy (ICP-OES). The concentration levels of all the studied HMs including As, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in dust were higher than those of soil. Health risks attributed to the HMs in soil and dust were assessed using Monte Carlo simulation approach. Accordingly, the non-carcinogenic (2.60E+1) and carcinogenic (1.71E-5) risks associated with the children's exposure to HM-polluted dust in these places were relatively high. Positive Matrix Factorization (PMF) model and its integration with health risk assessment models showed that the lithogenic source was the main contributor to both HMs concentrations and HMs-induced health risks with >65% contribution. The HMs in the dust accumulated on the equipment surface were found to be originated from the local (suspended local soil) and distant (industrial and traffic airborne emissions) sources, and from the plastic material of play equipment. The latter showed the highest contribution to the non-carcinogenic risk (37.5%). The results of this study imply the necessity for regularly cleaning of touchable surfaces in children's playgrounds, protecting the play equipment against aggressive environmental conditions, and controlling the critical sources of pollution.

Разработка конструкции индуктора для закалки детали сложной формы

Due to active process of import substitution, domestic industry starts producing the parts previously purchased abroad. These parts are necessary for stable and reliable operation of various technical objects and systems. Thus, the development of a technological installation for hardening a metal profile is topical. The task is complicated by the fact that the profile has very thin irregularly shaped walls, which should be hardened only from the inside, while the outer wall of the profile should be heated minimally to maintain strength. The studies have been carried out on simulation models of electromagnetic and thermal fields, which make it possible to reproduce the process of induction heating of the research object. Since the part has the same shape along the entire length, the simulation of the process of its induction heating is performed in two-dimensional space. The authors have developed a simulation model of the process of induction heating of a part of a non-standard shape, which includes calculations of thermal and electromagnetic fields. The design of the inductor is proposed, supplemented with ferrite inserts, which makes it possible to achieve the temperature regime necessary for the hardening process. The developed simulation model makes it possible to evaluate the distribution of the thermal and electromagnetic fields of the part, thereby predicting getting the temperatures required for its hardening when using various designs of inductors. The results of numerical experiments are consistent with the physical concepts of induction heating and prove the possibility to use induction hardening for thin-walled parts of complex shape instead of laser hardening used for this type of parts. The proposed model can be used in engineering practice to design inductors of non-standard parts.

Intrinsic Factors Contributing to Shrimp and Blood Clamp Allergic Reaction and Allergic Like Symptoms

Factors that contribute to food allergenicity is still unknown. To determine food intrinsic properties that contribute to L. vannamei and A. granosa allergenicity or allergy like symptoms this study identify total protein and metal profiles, histamine contents, and protein heat stability. Histamine content is measured colorimetrically. Protein heat-stability is observed with sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS-PAGE). Allergy-related metal concentration are determined with Atomic Absorption Spectroscopy (AAS). Fresh L. vannamei and A. granosa contained ~100 and ~25 ppm histamine, respectively. Storage at -20 oC for 3 days relatively did not changed histamine content of both foods. Storage at 4-8 oC for 3 days increased histamine content in L. vannamei, but not in A. granosa. Protein sized <70 kDa of both samples are relatively heat-stable. L. vannamei and A. granosa contained Zn with concentration of 85 ppm and 92 ppm, subsequently. All samples did not contain nickel (Ni), chromium (Cr), and lead (Pb). Higher histamine content and heat-stable protein number of L. vannamei could contribute to higher prevalence of its allergy or allergic like symptoms than A. granosa. High Zn content might contribute to allergic like symptoms of both foods.

Direct observation of hot-electron-enhanced thermoelectric effects in silicon nanodevices

The study of thermoelectric behaviors in miniatured transistors is of fundamental importance for developing bottom-level thermal management. Recent experimental progress in nanothermetry has enabled studies of the microscopic temperature profiles of nanostructured metals, semiconductors, two-dimensional material, and molecular junctions. However, observations of thermoelectric (such as nonequilibrium Peltier and Thomson) effect in prevailing silicon (Si)—a critical step for on-chip refrigeration using Si itself—have not been addressed so far. Here, we carry out nanothermometric imaging of both electron temperature (Te) and lattice temperature (TL) of a Si nanoconstriction device and find obvious thermoelectric effect in the vicinity of the electron hotspots: When the electrical current passes through the nanoconstriction channel generating electron hotspots (with Te~1500 K being much higher than TL~320 K), prominent thermoelectric effect is directly visualized attributable to the extremely large electron temperature gradient (~1 K/nm). The quantitative measurement shows a distinctive third-power dependence of the observed thermoelectric on the electrical current, which is consistent with the theoretically predicted nonequilibrium thermoelectric effects. Our work suggests that the nonequilibrium hot carriers may be potentially utilized for enhancing the thermoelectric performance and therefore sheds new light on the nanoscale thermal management of post-Moore nanoelectronics.

The integrated metallicity profile of the Milky Way

The heavy element abundance profiles of galaxies place stringent constraints on galaxy growth and assembly history. As the Milky Way is currently the only spiral galaxy in which we can measure temporally resolved chemical abundances, it enables insights into the origin of metallicity gradients and their correlation with the growth history of galaxies. However, until now, these abundance profiles have not been translated into the integrated-light measurements that are needed to compare the Milky Way with the general galaxy population. Here we report the measurement of the light-weighted, integrated stellar metallicity profile of our Galaxy. We find that the integrated stellar metallicity profile of the Milky Way has a ∧-like broken shape, with a mildly positive gradient inside a Galactocentric radius of 7 kpc and a steep negative gradient outside. This broken integrated metallicity profile of the Milky Way is not unique but is not common among Milky Way-mass star-forming galaxies observed in the MaNGA survey and simulated in the TNG50 cosmological simulation. Our results suggest that the Milky Way might not have a typical metallicity distribution for a galaxy of its mass, and thus offers valuable insight into the rich variety of galaxy enrichment processes.

Heavy metal concentration profiles and pollution assessment in the Jiangsu offshore area, China

The concentration profiles of various major and trace heavy metals (Cu, Pb, Zn, Cr, Cd, As, Hg, Ni, Li, and Co) were investigated along a 40.1-m-long sediment core in the offshore Jiangsu area of China, to assess their depositional trends and contamination levels. All metals, except Cd, exhibited similar profiles with high average concentrations during the Marine Isotope Stage 2–4 period. The sediment trace-metal concentrations were primarily related to grain size and sediment sources, with almost all heavy metals (except Cd) being positively correlated. Enrichment factors, geoaccumulation indices, and principal component analysis indicated no elemental enrichment or contamination. The high EF and Igeo values of As, Hg, and Li may be related to their background values.

Design and Development of Shape Memory Alloy Actuator for Preventing and Protecting Electrical Wires

Fatigue failure of wires is a frequent issue that evolves over time as a result of utilizing the profile under variable stress and temperature. In this article, an innovative study makes it possible to propose a protective tool for metal profiles against fatigue using shape memory alloys (SMA). Smart actuators like SMA are able to push back sudden stresses above the elastic limit, therefore, are characterized by high resistance to fatigue and even against corrosion due to their strong thermomechanical coupling. Besides, the study provides the results necessary to add a layer based on the shape memory tube to protect the important connectors for industrial systems and automotive industries. The conductivity of electrical current in various electronic devices depends on the copper material, which is good at conducting electricity and heat but weak against mechanical forces and hence easily susceptible to fatigue. Thereby, the elastic regime of copper is different from that of SMA, and in order to adapt the properties of two materials, a mathematical study can describe the behaviour of two combined systems is important for the analysis of the cyclic effect and for adapting the proposed actuator in wiring technology. Therefore, the study shows the great potential of the proposed SMA tube with its superelastic behaviour to increase the predicted lifespan of metallic wires against corrosion and fatigue. The lifetime of the conduction system with the protective SMA is increased remarkably and can reach up to 105cycles under the action of the stress of an amplitude of 550 MPa, the finite element simulation shows that the system of SMA combined with a 4 mm wire undergoing significant stress up to 490 MPa that can reach a deformation of 7% and return to the initial state without residual deformation. The simulation's results look at the evolution of stress, strain, fatigue lifetimes, and anticipated damage, and they match the experimental results of SMA tube properties rather well. Consequently, the verification of the proposed model confirms the improvement in the lifespan of studied wires compared to wires without SMA encapsulation.

Emission inventories, emission factors, and composition profiles of volatile organic compounds (VOCs) and heavy metals (HMs) from an e-waste dismantling park in southern China

Electronic waste (e-waste) dismantling is a significant source of atmospheric pollutants, including volatile organic compounds (VOCs) and heavy metals (HMs), which may have adverse effects on the surrounding environment and residents. However, the organized emission inventories and emission characteristics of VOCs and HMs from e-waste dismantling are not well documented. In this study, the concentrations and components of VOCs and HMs were monitored at the exhaust gas treatment facility from two process areas of a typical e-waste dismantling park in southern China in 2021. Emission inventories of VOCs and HMs were established, with total emissions of 8.85 t/a and 18.3 kg/a for VOCs and HMs in this park, respectively. The cutting & crushing (CC) area was the largest emissions source, accounting for 82.6% of VOCs and 79.9% of HMs, respectively, while the baking plate (BP) area had higher emission factors. Additionally, the concentration and composition of VOCs and HMs in the park were also analyzed. For VOCs, the concentrations of halogenated hydrocarbons and aromatic hydrocarbons were comparable in the park, while m/p-xylene, o-xylene, and chlorobenzene were the key VOC species. The HM concentrations followed the order of Pb > Cu > Mn > Ni > As > Cd > Hg, with Pb and Cu being the main heavy metals released. This is the first VOC and HM emission inventory for the e-waste dismantling park, and our data will lay a solid ground for pollution control and management for the e-waste dismantling industry.

Deciphering the dynamics of metal and antibiotic resistome profiles under different metal(loid) contamination levels

Metal(loid) contaminations pose considerable threats to ecological security and public health, yet little is known about the dynamics of metal resistance genes (MRGs) and antibiotic resistance genes (ARGs) under different metal(loid) contamination levels. Here, we provided a systematic investigation of MRGs and ARGs in three zones (Zones I, II, and III) with different metal(loid) contamination levels across an abandoned sewage reservoir. More diverse MRGs and ARGs were detected from the high-contaminated Zone I and the moderate-contaminated Zone II, while the abundant MGEs (mobile genetic elements) potentially enhanced the horizontal gene transfer potential and the resistome diversity in Zone I. Particularly, resistome hosts represented by Thiobacillus, Ramlibacter, and Dyella were prevalent in Zone II, promoting the vertical gene transfer of MRGs and ARGs. The highest health risk of ARGs was predicted for Zone I (about 7.58% and 0.48% of ARGs classified into Rank I and Rank II, respectively), followed by Zone II (2.11% and 0%) and Zone III (0% and 0%). However, the ARGs co-occurring with MRGs might exhibit low proportions and low health risks (all were Rank IV) in the three zones. Overall, these findings uncovered the dynamic responses of resistomes and their hosts to different metal(loid) contamination levels, contributing to formulating accurate management and bioremediation countermeasures for various metal(loid) contaminated environments.

Total secondary metabolites and heavy metal profile of some medicinal plants frequently consumed as winter tea

In this study, sage (Salvia officinalis L.), linden (Tilia platyphyllos Scop.), and daisy (Matricaria chamomilla L.) herbs, which have rich phytochemical content and are frequently consumed in winter months for medicinal purposes, were obtained from three different herbalists located in Bingol and investigated in terms of their heavy metal contents, total flavonoid, total anthocyanin and total polyphenol contents. Some of the heavy metal (Cr, Fe, Co, Ni, Cu, Zn, As, Hg, Pb) contents of the collected herb samples were determined by ICP-MS. Total flavonoid, total anthocyanin and total polyphenol contents were determined by analyzing spectrophotometric methods. While the total phenolic content was found the most in sage (S1) ethylacetate and methanol extracts (760.1±2.0, 410.33±1.5 mg GAE/g), it was found the least in linden (L1, L3) hexane extracts (6.66±.1.3, 8.35±0.8 mg GAE/g). It was determined that total flavonoid content and total anthocyanin contents were higher in sage (S1) ethylacetate (294.31±2.1 mg CE/g and 291.31±2.1 mg MvGE/g), sage (S2) methanol (375.0±1.9 mg CE/g and 139.01*±2.0 mg MvGE/g) extracts, and less in linden (L1) and daisy (D1) hexane extracts respectively. It was determined that Cr and Cu metals were among the values suitable for consumption in terms of health in all samples except the chamomile (D1, D3) samples, and Zn metals were among the values suitable for consumption in all samples except the linden (L2) sample. Furthermore, the toxic metal Cd (0.05±0.00- 0.09±0.00 μg/g) in daisy (D1, D3) samples, as well as the other toxic metal Pb (4.50±0.01-6.43±0.01 μg/g) in sage (S1,S2,S3) and linden (L1,L2,L3) samples, were found to be among the values suitable for consumption in terms of health. As a result, when the total anthocyanin, polyphenol and flavonoid contents were compared in all groups it was found that sage had the highest value in ethyl acetate extract. Additionally, Cu and Ni values of sage, and Fe and Pb values in both sage and linden were within safe limits in terms of health. They are of utmost importance in terms of supporting the daily mineral intake. However, As, Pb, and Hg were found to be toxic in daisy extract. This result can be shown as a result that the daisy will be a bioaccumulator. Therefore, consumption of daisy tea should be limited.

Metals profile in deep-sea sediment from an active tectonic region around Simeulue Island, Aceh, Indonesia

Simeulue waters are adjacent to the northern part of Sumatra Island, which is undergoing massive land-use transformations; moreover, the waters are located in an active tectonic region. Land changes and tectonic activity might affect the metal pollution profile in this deep sea area. Thus, this study aimed to investigate the vertical profile and assess the sediment quality from the deep-sea marine sediment around Simeulue Island based on metal concentration. Seventy-six bottom sediment samples were collected from eight cores at a water depth of up to 2800 m in the Simeulue waters, Indonesia, in November 2017. Metals Cd, Cu, Fe, Ni, Pb, and Zn were quantified from the cores and multivariate analyses were carried out to understand the process. Metals distributions are analogous to the grain size parameters and LOI550 distribution pattern, while Sumatra and Simeulue islands influenced grain size and LOI550 spatial distribution. The vertical grain size profile exhibited no extreme oscillation in the investigated cores. Thus, sediment transport from the Island was the main suspect for these metals' profiles in the deep water, and the tectonic activity had a minor impact. Cu, Ni, Pb, and Zn tend to rise in the collected cores, suggesting that the accumulation of the metals is growing. While Fe tended to be stable and Cd oscillated in the cores. Indices were computed to assess the metal contamination profile. The cores were dominated by EF class 1 (none to slight enrichment) status and Igeo class 1 (unpolluted). Cd was the metal of concern in the study since a high Cd was observed in some layers (maximum EF = 26.45 and maximum Igeo = 3.81). Thus, this study can be used as a database to improve the regulation formulation for improved environmental managerial efforts in the region.

The Control and Comprehensive Safety Assessment of Heavy Metal Impurities (As, Pb, and Cd) in Green Tea Camellia sinensis (L.) Samples (Infusions) Available in Poland

Tea is the world’s most common drink after water, and the world’s annual sales exceed $43 billion, of which more than $11 billion is green tea (Camellia sinensis (L.)). Increasing evidence continues to show that green tea consumption and its ingredients have a variety of potential health benefits. The aim of the study was to control and assess the toxicological risk (TRA) of three heavy metals (As, Pb, and Cd) in infusions of green tea (n = 12) from Polish markets. We applied the method of inductive coupled plasma mass spectrometry (ICP-MS) to determine the selected heavy metal and designed a specific toxicological risk assessment with three crucial tiers. The first tier of our strategy was to determine the elements investigated (heavy metal impurities, µg/L). The second step was to estimate the weekly intake of green tea infusions (µg/week) based on weekly consumption. The third tier was to estimate the weekly intake per weight (µg/L/week/bw), based on the average weekly intake of green tea infusion per adult compared to the provisional weekly intake (PTWI) established by the FAO/WHO Joint Food Additives Expert Committee (JECFA). The levels of the investigated heavy metals occur at different levels in all of the investigated green tea infusions. The heavy metal profile indicated that As (0.0721–10.585 µg/L), Pb (0.386–1.695 µg/L), and Cd (0.126–0.346 µg/L) were present in all samples. Basic analysis of general content shows that As (average = 0.325 µg/L) was at a level similar to Cd (average = 0.214 µg/L). Surprisingly, the Pb content (average 0.891 µg/L) was approximately 2.75–4 times higher than that of As and Cd, respectively. The application of our proposed safety assessment methodology (three tiers) provides satisfactory results for regulatory purposes. The evaluation of the investigated heavy metals in all products analysed from green tea samples (infusions) showed that there were no health hazards to consumers due to weekly exposure. The results indicated that after drinking green tea infusions from Polish markets, the amount of investigated elements in weekly doses does not represent any health risks to consumers.

The Initial Mass Function and Other Stellar Properties Across the Core of the Hydra I Cluster* * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

The Hydra I cluster offers an excellent opportunity to study and compare the relic old stellar populations in the core of its two brightest galaxies. In addition, the differing kinematics of the two galaxies allows a test of the local validity of general scaling relations. In this work, we present a direct comparison employing full spectral fitting of new high-quality long-slit optical and near-infrared spectroscopic data. We retrieve age, metallicity, and 19 elemental abundances out to ∼12 kpc within each galaxy, as well as the Initial Mass Function (IMF) in their central regions. Our results suggest that the inner ∼5 kpc regions of both galaxies, despite their different masses, formed at the same time and evolved with a similar star formation timescale and chemical enrichment, confirming their early formation in the cluster buildup. Only the overall metallicity and IMF radial profiles show differences connected with their different velocity dispersion profiles. The radial trends of the IMF positively correlate with both [Z/H] and σ. While the trends of the IMF slope values with metallicity agree with a global trend for both galaxies, the trends with the velocity dispersion exhibit differences. The outer regions show signs of mixed stellar populations with large differences in chemical content compared to the centers, but with similarly old ages.

Redox and metal profiles in human coronary endothelial and smooth muscle cells under hyperoxia, physiological normoxia and hypoxia: Effects of NRF2 signaling on intracellular zinc

Zinc is an important component of cellular antioxidant defenses and dysregulation of zinc homeostasis is a risk factor for coronary heart disease and ischemia/reperfusion injury. Intracellular homeostasis of metals, such as zinc, iron and calcium are interrelated with cellular responses to oxidative stress. Most cells experience significantly lower oxygen levels in vivo (2–10 kPa O2) compared to standard in vitro cell culture (18kPa O2). We report the first evidence that total intracellular zinc content decreases significantly in human coronary artery endothelial cells (HCAEC), but not in human coronary artery smooth muscle cells (HCASMC), after lowering of O2 levels from hyperoxia (18 kPa O2) to physiological normoxia (5 kPa O2) and hypoxia (1 kPa O2). This was paralleled by O2-dependent differences in redox phenotype based on measurements of glutathione, ATP and NRF2-targeted protein expression in HCAEC and HCASMC. NRF2-induced NQO1 expression was attenuated in both HCAEC and HCASMC under 5 kPa O2 compared to 18 kPa O2. Expression of the zinc efflux transporter ZnT1 increased in HCAEC under 5 kPa O2, whilst expression of the zinc-binding protein metallothionine (MT) decreased as O2 levels were lowered from 18 to 1 kPa O2. Negligible changes in ZnT1 and MT expression were observed in HCASMC. Silencing NRF2 transcription reduced total intracellular zinc under 18 kPa O2 in HCAEC with negligible changes in HCASMC, whilst NRF2 activation or overexpression increased zinc content in HCAEC, but not HCASMC, under 5 kPa O2. This study has identified cell type specific changes in the redox phenotype and metal profile in human coronary artery cells under physiological O2 levels. Our findings provide novel insights into the effect of NRF2 signaling on Zn content and may inform targeted therapies for cardiovascular diseases.

Strength of connection profiles used in cross-laminated timber walls under seismic load

Cross-laminated wood (CLT) material, which has many advantages, has been widely used in architectural designs as a building element and building material in recent years. It has been proven that CLT can also show high performance against ground vibrations, but it is also mentioned in the literature that some problems such as rupture, snagging, and breaking occur in the elements used in the connections of the walls to the floor and the ground. This study was conducted to examine the performance of fasteners used in CLT walls against lateral load. In this context, 4 CLT walls were produced and then 5 metal profiles were designed to be used in the connection of these walls with the foundation ground. CLT wall and connection profiles, created according to ASTM E 72 standards, have been tested in an experimental setup with different detail options. According to the test results, it was observed that some of the CLT walls and connection profiles showed high performance at maximum load, displacement, and stiffness values. As a result, it has been determined that the resistance of the CLT material against lateral earthquake load can be increased with the right fasteners, and the collapse time of the structure in the event of an earthquake can be indirectly extended.