Micronutrient Deficiency May Be Associated with the Onset of Chalkbrood Disease in Honey Bees.

Chalkbrood is a disease of honey bee brood caused by the fungal parasite Ascosphaera apis. Many factors such as genetics, temperature, humidity and nutrition influence the appearance of clinical symptoms. Poor nutrition impairs the immune system, which favors the manifestation of symptoms of many honey bee diseases. However, a direct link between dietary ingredients and the symptoms of chalkbrood disease has not yet been established. We show here that the elemental composition of chalkbrood mummies and healthy larvae from the same infected hives differ, as well as that mummies differ from larvae from healthy hives. Chalkbrood mummies had the highest concentration of macroelements such as Na, Mg, P, S, K and Ca and some microelements such as Rb and Sn, and at the same time the lowest concentration of B, As, Sr, Ag, Cd, Sb, Ba and Pb. Larvae from infected hives contained less Pb, Ba, Cs, Sb, Cd, Sr, As, Zn, Cu, Ni, Co, Mn, Cr, V and Al in contrast to healthy larvae from a disease-free apiary. This is the first study to demonstrate such differences, suggesting that an infection alters the larval nutrition or that nutrition is a predisposition for the outbreak of a chalkbrood infection. Though, based on results obtained from a case study, rather than from a controlled experiment, our findings stress the differences in elements of healthy versus diseased honey bee larvae.

Sex-specific element accumulation in honey bees (Apis mellifera).

Honey bees are social insects that show division of labor and sexual dimorphism. Female honey bees differentiate in two different castes, queens or worker bees, while males are called drones. Worker bees have different tasks in the hive including collection of food, its processing, caring for brood, protecting the hive, or producing wax. The drones' only role is to mate with a virgin queen. Many studies have dealt with differences in physiology, behavior, and morphology of workers and drones. This is the first study that demonstrates differences in element accumulation and composition between workers and drones honey bees. Using inductively coupled plasma mass spectrometry, we found that worker honey bees have higher concentrations of most elements analyzed. Drones had higher concentrations of elements essential to bees, Na, P, S, Zn, Cu, and especially Se (2.2 × higher), which is known to be important for sperm quality and fertility in many animals. Until now higher Se content was not observed in male insects. These differences can be attributed to different environmental exposure, reproductive role of drones, but mostly to the food workers and drones consume. Worker bees feed on bee bread, which is rich in minerals. Drones are fed food pre-processed by worker bees.

Tattoo Pigment Biokinetics in vivo in a 28-Day Porcine Model: Elements Undergo Fast Distribution to Lymph Nodes and Reach Steady State after 7 Days.

INTRODUCTION: Pigments of tattoo inks may over time migrate to other parts of the body. Inks kinetics are still poorly understood and little studied. The aim of this first study was to investigate the kinetics of tattoo inks pigment in tattooed porcine skin, which is closer to human skin than mouse skin studied in the past. METHODS: Three animals were tattooed on the inner thigh and one animal served as untreated control. Skin biopsies were taken on days 7, 14, and 28 after tattooing. Animals were sacrificed on day 28 and homogenate samples of the liver, spleen, kidney, and brain, as well the local lymph nodes were prepared. All samples were analyzed for ink components using inductively coupled plasma-mass spectrometry. The ink itself was characterized by dynamic light scattering and matrix-assisted laser desorption-ionization mass analysis. RESULTS: Titanium (212 g/kg), copper (6 mg/kg), aluminum (1 mg/kg), zirconium (1 mg/kg), and chromium (3 mg/kg) were found in the ink. Significant deposits of ink elements were detected in the tattooed skin when compared to non-tattooed skin from the same animal (mean ± standard deviation: titanium 240 ± 81 mg/kg, copper 95 ± 39 mg/kg, aluminum 115 ± 63 mg/kg, zirconium 23 ± 12 mg/kg, and chromium 1.0 ± 0.2 mg/kg; p < 0.05). Lymph node concentrations of titanium, copper, aluminum, zirconium, and chromium were 42 ± 2 mg/kg, 69 ± 25 mg/kg, 49 ± 18 mg/kg, 0.3 ± 0.2 mg/kg, 0.5 ± 0.2 mg/kg, respectively. CONCLUSION: Deposits in skin were unchanged from days 7-28 indicating no redistribution or elimination. No significant deposits of ink elements were found in the liver, spleen, kidney, and brain. In conclusion, our findings confirmed distribution of elements from tattoos to regional lymph nodes, but neither to excretory organs, e.g., liver and kidney, nor to spleen and brain. Thus systemic internal organ exposure was not found.

First clinical evidence that trimethylsulfonium can serve as a biomarker for the production of the signaling molecule hydrogen sulfide.

BACKGROUND: Hydrogen sulfide (H2S) is established as the third gaseous signaling molecule and is known to be overproduced in down syndrome (DS) due to the extra copy of the CBS gene on chromosome 21, which has been suggested to contribute to the clinical manifestation of this condition. We recently discovered trimethylsulfonium (TMS) in human urine and highlighted its potential as a selective methylation metabolite of endogenously produced H2S, but the clinical utility of this novel metabolite has not been previously investigated. We hypothesize that the elevation of H2S production in DS would be reflected by an elevation in the methylation product TMS. METHODS: To test this hypothesis, a case-control study was performed and the urinary levels of TMS were found to be higher in the DS group (geo. mean 4.5 nM, 95 % CI 2.4-3.9) than in the control (N) group (3.1 nM, 3.5-6.0), p-value 0.01, whereas the commonly used biomarker of hydrogen sulfide, thiosulfate, failed to reflect this alteration in H2S production (15 µM (N) vs. 13 µM (DS), p-value 0.24. RESULTS: The observed association is in line with the proposed hypothesis and provides first clinical evidence of the utility of TMS as a novel and more sensitive biomarker for the endogenous production of the third gaseous signaling molecule than the conventionally used biomarker thiosulfate, which is heavily dependent on bacterial hydrogen sulfide production. CONCLUSION: This work shows that TMS must be explored in clinical conditions where altered metabolism of hydrogen sulfide is implicated.

Arsenobetaine amide: a novel arsenic species detected in several mushroom species.

The total arsenic mass fraction as well as the arsenic speciation were studied in four different mushroom species with inductively coupled plasma mass spectrometry and high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry, respectively. Arsenic mass fractions detected in the mushrooms were covering a range from 0.3 to 22 mg As kg-1 dry mass. For the arsenic speciation, species like arsenobetaine, inorganic arsenic, or dimethylarsinic acid were found, which are commonly detected in mushrooms, but it was also proven that the recently discovered novel compound homoarsenocholine is present in Amanita muscaria and Ramaria sanguinea. Moreover, a previously unidentified arsenic species was isolated from Ramaria sanguinea and identified as trimethylarsonioacetamide, or in short: arsenobetaine amide. This new arsenical was synthesized and verified by spiking experiments to be present in all investigated mushroom samples. Arsenobetaine amide could be an important intermediate to further elucidate the biotransformation pathways of arsenic in the environment.

Multimodal analytical tools for the molecular and elemental characterisation of lesions in brain tissue of multiple sclerosis patients.

Multiple sclerosis (MS) is a prevalent immune-mediated inflammatory disease of the central nervous system inducing a widespread degradation of myelin and resulting in neurological deficits. Recent advances in molecular and atomic imaging provide the means to probe the microenvironment in affected brain tissues at an unprecedented level of detail and may provide new insights. This study showcases state-of-the-art spectroscopic and mass spectrometric techniques to compare distributions of molecular and atomic entities in MS lesions and surrounding brain tissues. MS brains underwent post-mortem magnetic resonance imaging (MRI) to locate and subsequently dissect MS lesions and surrounding white matter. Digests of lesions and unaffected white matter were analysed via ICP-MS/MS revealing significant differences in concentrations of Li, Mg, P, K, Mn, V, Rb, Ag, Gd and Bi. Micro x-ray fluorescence spectroscopy (µXRF) and laser ablation - inductively coupled plasma - time of flight - mass spectrometry (LA-ICP-ToF-MS) were used as micro-analytical imaging techniques to study distributions of both endogenous and xenobiotic elements. The essential trace elements Fe, Cu and Zn were subsequently calibrated using in-house manufactured gelatine standards. Lipid distributions were studied using IR-micro spectroscopy and matrix assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI). MALDI-MSI was complemented with high-resolution tandem mass spectrometry and trapped ion mobility spectroscopy for the annotation of specified phospho- and sphingolipids, revealing specific lipid species decreased in MS lesions compared to surrounding white matter. This explorative study demonstrated that modern molecular and atomic mapping techniques provide high-resolution imaging for relevant bio-indicative entities which may complement our current understanding of the underlying pathophysiological processes.

Metal Concentrations in E-Cigarette Aerosol Samples: A Comparison by Device Type and Flavor.

BACKGROUND: The rapid evolution of electronic cigarette (e-cigarette) products warrants surveillance of the differences in exposure across device types-modifiable devices (MODs), cartridge ("pod")-containing devices (PODs), disposable PODs (d-PODs)-and flavors of the products available on the market. OBJECTIVE: This study aimed to measure and compare metal aerosol concentrations by device type and common flavors. METHODS: We collected aerosol from 104 MODs, 67 PODs (four brands: JUUL, Bo, Suorin, PHIX), and 23 d-PODs (three brands: ZPOD, Bidi, Stig) via droplet deposition in a series of conical pipette tips. Metals and metalloids [aluminum (Al), arsenic (As), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), tin (Sn), and zinc (Zn)] were measured using inductively coupled plasma mass spectrometry (ICP-MS), results were log-transformed for statistical analysis, and concentrations are reported in aerosol units (mg/m3). RESULTS: Of the 12 elements analyzed, concentrations were statistically significantly higher in MOD devices, except for Co and Ni, which were higher in PODs and d-PODs. Of the POD brands analyzed, PHIX had the highest median concentrations among four metals (Al, Ni, Pb, and Sn) compared to the rest of the POD brands. According to POD flavor, seven metals were three to seven orders of magnitude higher in tobacco-flavored aerosol compared to those in mint and mango flavors. Among the d-POD brands, concentrations of four metals (Al, Cu, Ni, and Pb) were higher in the ZPOD brand than in Bidi Stick and Stig devices. According to d-POD flavor, only Cr concentrations were found to be statistically significantly higher in mint than tobacco-flavored d-PODs. DISCUSSION: We observed wide variability in aerosol metal concentrations within and between the different e-cigarette device types, brands, and flavors. Overall, MOD devices generated aerosols with higher metal concentrations than PODs and d-PODs, and tobacco-flavored aerosols contained the highest metal concentrations. Continued research is needed to evaluate additional factors (i.e., nicotine type) that contribute to metal exposure from new and emerging e-cigarette devices in order to inform policy. https://doi.org/10.1289/EHP11921.

Levels of toxic and trace metals in the breast milk of lactating mothers in Abeokuta, Ogun State, Nigeria.

Background and objectives: Breast milk is an essential source of nutrients and energy for infants. The study analyzed for the levels of essential, toxic and rare earth elements in the breast milk of lactating mothers within Abeokuta metropolis. Materials and methods: Thirty-seven (37) breast milk samples were collected with consents of lactating mothers at Ogun State General Hospital in Abeokuta. The samples were digested using standard method and analyzed for essential, toxic and rare earth elements using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The data were subjected to descriptive analysis. Results: The results showed higher concentrations of toxic elements than essential elements in the breast milk of lactating mothers, where five toxic metals: Ag, Ti, V, Pb and Ba were observed to be present in 11, 14, 15, 17 and 23 breast milk samples respectively. Two essential (P and S) and two toxic (Cd and Hg (except sample 19)) elements were observed to be present in all the breast milk samples. Rare Earth Elements (except Sr, U and Rb) were below the detection limit of the instrument. Though three breast milk samples (12, 14 and 17) were observed safe, they contained two toxic (Cd and Hg) and a rare earth trace (Rb) element. Conclusion: It could be concluded that despite the inherent benefits of human breast milk with essential elements to the infants, it can still be a source of toxic and trace earth metals contamination.

Metal mixtures and DNA methylation measures of biological aging in American Indian populations.

INTRODUCTION: Native American communities suffer disproportionately from elevated metal exposures and increased risk for cardiovascular diseases and diabetes. DNA methylation is a sensitive biomarker of aging-related processes and novel epigenetic-based "clocks" can be used to estimate accelerated biological aging that may underlie increased risk. Metals alter DNA methylation, yet little is known about their individual and combined impact on epigenetic age acceleration. Our objective was to investigate the associations of metals on several DNA methylation-based aging measures in the Strong Heart Study (SHS) cohort. METHODS: Blood DNA methylation data from 2,301 SHS participants was used to calculate age acceleration of epigenetic clocks (PhenoAge, GrimAge, DunedinPACE, Hannum, Horvath). Urinary metals [arsenic (As), cadmium (Cd), tungsten (W), zinc (Zn), selenium (Se), molybdenum (Mo)] were creatinine-adjusted and categorized into quartiles. We examined associations of individual metals through linear regression models and used Bayesian Kernel Machine Regression (BKMR) for the impact of the total metal mixture on epigenetic age acceleration. RESULTS: The mixture of nonessential metals (W, As, Cd) was associated with greater GrimAge acceleration and DunedinPACE, while the essential metal mixture (Se, Zn, Mo) was associated with lower epigenetic age acceleration. Cd was associated with increased epigenetic age acceleration across all clocks and BKMR analysis suggested nonlinear associations between Se and DunedinPACE, GrimAge, and PhenoAge acceleration. No interactions between individual metals were observed. The associations between Cd, Zn, and epigenetic age acceleration were greater in never smokers in comparison to current/former smokers. CONCLUSION: Nonessential metals were positively associated with greater epigenetic age acceleration, with strongest associations observed between Cd and DunedinPACE and GrimAge acceleration. In contrast, essential metals were associated with lower epigenetic aging. Examining the influence of metal mixtures on epigenetic age acceleration can provide insight into metals and aging-related diseases.

Anthropometric measures and arsenic methylation among pregnant women in rural northern Bangladesh.

INTRODUCTION: Arsenic methylation converts inorganic arsenic (iAs) to monomethyl (MMA) and dimethyl (DMA) arsenic compounds. Body mass index (BMI) has been positively associated with arsenic methylation efficiency (higher DMA%) in adults, but evidence in pregnancy is inconsistent. We estimated associations between anthropometric measures and arsenic methylation among pregnant women in rural northern Bangladesh. METHODS: We enrolled pregnant women (n = 784) (median [IQR] gestational week: 14 [13, 15]) in Gaibandha District, Bangladesh from 2018 to 2019. Anthropometric measures were BMI, subscapular and triceps skinfold thicknesses, and mid-upper arm circumference (MUAC), fat area (MUAFA), and muscle area (MUAMA). Arsenic methylation measures were urinary iAs, MMA, and DMA divided by their sum and multiplied by 100 (iAs%, MMA%, and DMA%), primary methylation index (MMA/iAs; PMI), and secondary methylation index (DMA/MMA; SMI). In complete cases (n = 765 [97.6%]), we fitted linear, beta, and Dirichlet regression models to estimate cross-sectional differences in iAs%, MMA%, DMA%, PMI, and SMI per IQR-unit difference in each anthropometric measure, adjusting for drinking water arsenic, age, gestational age, education, living standards index, and plasma folate, vitamin B12, and homocysteine. RESULTS: Median (IQR) BMI, subscapular skinfold thickness, triceps skinfold thickness, MUAC, MUAFA, and MUAMA were 21.5 (19.4, 23.8) kg/m2, 17.9 (13.2, 24.2) mm, 14.2 (10.2, 18.7) mm, 25.9 (23.8, 28.0) cm, 15.3 (10.5, 20.3) cm2, and 29.9 (25.6, 34.2) cm2, respectively. Median (IQR) iAs%, MMA%, DMA%, PMI, and SMI were 12.0 (9.3, 15.2)%, 6.6 (5.3, 8.3)%, 81.0 (77.1, 84.6)%, 0.6 (0.4, 0.7), and 12.2 (9.3, 15.7), respectively. In both unadjusted and adjusted linear models, all anthropometric measures were negatively associated with iAs%, MMA%, and PMI and positively associated with DMA% and SMI. For example, fully adjusted mean differences (95% CI) in DMA% per IQR-unit difference in BMI, subscapular skinfolds thickness, triceps skinfold thickness, MUAC, MUAFA, and MUAMA were 1.72 (1.16, 2.28), 1.58 (0.95, 2.21), 1.74 (1.11, 2.37), 1.45 (0.85, 2.06), 1.70 (1.08, 2.31), and 0.70 (0.13, 1.27) pp, respectively. CONCLUSIONS: Anthropometric measures were positively associated with arsenic methylation efficiency among pregnant women in the early second trimester.

Determination of Phosphoethanolamine in Urine with HPLC-ICPMS/MS Using 1,2-Hexanediol as a Chromatographic Eluent.

The importance of element-selective detection with inductively coupled plasma mass spectrometry (ICPMS) has been significantly increased in recent years following the introduction of tandem ICPMS (ICPMS/MS), which unlocked access to nonmetal speciation analysis. However, nonmetals are ubiquitous, and the feasibility of nonmetal speciation analysis in matrices with complex metabolomes is yet to be demonstrated. Herein, we report the first phosphorous speciation study by HPLC-ICPMS/MS in a human sample, namely, urine, involving the determination of the natural metabolite and biomarker phosphoethanolamine. A simple one-step derivatization procedure was employed to enable the separation of the target compound from the hydrophilic phosphorous metabolome in urine. The challenge of eluting the hydrophobic derivative under ICPMS-compatible chromatographic conditions was addressed by employing hexanediol, a novel chromatographic eluent recently described in our previous work but has not yet been exploited in a real-world application. The developed method features fast chromatographic separation (<5 min), no need for an isotopically labeled internal standard, and an instrumental LOD of 0.5 µg P L-1. The method was evaluated for recovery (90-110%), repeatability (RSD ±5%), and linearity (r2 = 0.9998). The method accuracy was thoroughly examined by comparing with an independently developed method based on HPLC-ESIMS/MS without derivatization, where agreement was found within ±5-20%. An application is presented to gain first insight into the variability in the human excretion of phosphoethanolamine, which is key for the interpretation of its levels as a biomarker, by repeated urine collection from a group of volunteers over 4 weeks.

A time-course investigation of the human urinary excretion of the hydrogen sulfide biomarker trimethylsulfonium.

Hydrogen sulfide is a toxic gas but also recognized as an endogenously produced metabolite in humans playing key roles. We previously identified trimethylsulfonium, which can be a methylation product of hydrogen sulfide but the stability in the production of trimethylsulfonium has not been investigated. In the present work, the intra- and inter-individual variability in the excretion of trimethylsulfonium over 2 months in a group of healthy volunteers was investigated. Urinary levels of trimethylsulfonium (mean: 56 nM, 95% CI: 48-68 nM) were > 100-fold lower than the conventional hydrogen sulfide biomarker thiosulfate (13 µM, 12-15 µM) and the precursor for endogenous hydrogen sulfide production cystine (47 µM, 44-50 µM). There was no correlation between urinary trimethylsulfonium and thiosulfate. Higher intra-individual variability in the excretion of trimethylsulfonium (generally 2-8 fold) than that for cystine (generally 2-3 fold) was found. Trimethylsulfonium displayed significant inter-individual variability with two concentration clusters at 117 nM (97-141) and 27 nM (22-34). In conclusion, the observed inter- and intra-individual variability must be considered when using urinary trimethylsulfonium as a biomarker.

Autolysis Affects the Iron Cargo of Ferritins in Neurons and Glial Cells at Different Rates in the Human Brain.

Iron is known to accumulate in neurological disorders, so a careful balance of the iron concentration is essential for healthy brain functioning. An imbalance in iron homeostasis could arise due to the dysfunction of proteins involved in iron homeostasis. Here, we focus on ferritin-the primary iron storage protein of the brain. In this study, we aimed to improve a method to measure ferritin-bound iron in the human post-mortem brain, and to discern its distribution in particular cell types and brain regions. Though it is known that glial cells and neurons differ in their ferritin concentration, the change in the number and distribution of iron-filled ferritin cores between different cell types during autolysis has not been revealed yet. Here, we show the cellular and region-wide distribution of ferritin in the human brain using state-of-the-art analytical electron microscopy. We validated the concentration of iron-filled ferritin cores to the absolute iron concentration measured by quantitative MRI and inductively coupled plasma mass spectrometry. We show that ferritins lose iron from their cores with the progression of autolysis whereas the overall iron concentrations were unaffected. Although the highest concentration of ferritin was found in glial cells, as the total ferritin concentration increased in a patient, ferritin accumulated more in neurons than in glial cells. Summed up, our findings point out the unique behaviour of neurons in storing iron during autolysis and explain the differences between the absolute iron concentrations and iron-filled ferritin in a cell-type-dependent manner in the human brain. The rate of loss of the iron-filled ferritin cores during autolysis is higher in neurons than in glial cells.

Maternal DNA methylation signatures of arsenic exposure is associated with adult offspring insulin resistance in the Strong Heart Study.

Exposure to low to moderate arsenic (As) levels has been associated with type 2 diabetes (T2D) and other chronic diseases in American Indian communities. Prenatal exposure to As may also increase the risk for T2D in adulthood, and maternal As has been associated with adult offspring metabolic health measurements. We hypothesized that T2D-related outcomes in adult offspring born to women exposed to low to moderate As can be evaluated utilizing a maternally-derived molecular biosignature of As exposure. Herein, we evaluated the association of maternal DNA methylation with incident T2D and insulin resistance (Homeostatic model assessment of insulin resistance [HOMA2-IR]) in adult offspring. For DNA methylation, we used 20 differentially methylated cytosine-guanine dinucleotides (CpG) previously associated with the sum of inorganic and methylated As species (ΣAs) in urine in the Strong Heart Study (SHS). Of these 20 CpGs, we found six CpGs nominally associated (p < 0.05) with HOMA2-IR in a fully adjusted model that included clinically relevant covariates and offspring adiposity measurements; a similar model that adjusted instead for maternal adiposity measurements found three CpGs nominally associated with HOMA2-IR, two of which overlapped the offspring adiposity model. After adjusting for multiple comparisons, cg03036214 remained associated with HOMA2-IR (q < 0.10) in the offspring adiposity model. The odds ratio of incident T2D increased with an increase in maternal DNA methylation at one HOMA2-IR associated CpG in the model adjusting for offspring adiposity, cg12116137, whereas adjusting for maternal adiposity had a minimal effect on the association. Our data suggests offspring adiposity, rather than maternal adiposity, potentially influences the effects of maternal DNAm signatures on offspring metabolic health parameters. Here, we have presented evidence supporting a role for epigenetic biosignatures of maternal As exposure as a potential biomarker for evaluating risk of T2D-related outcomes in offspring later in life.

The Pregnancy, Arsenic, and Immune Response (PAIR) Study in rural northern Bangladesh.

BACKGROUND: Arsenic exposure and micronutrient deficiencies may alter immune reactivity to influenza vaccination in pregnant women, transplacental transfer of maternal antibodies to the foetus, and maternal and infant acute morbidity. OBJECTIVES: The Pregnancy, Arsenic, and Immune Response (PAIR) Study was designed to assess whether arsenic exposure and micronutrient deficiencies alter maternal and newborn immunity and acute morbidity following maternal seasonal influenza vaccination during pregnancy. POPULATION: The PAIR Study recruited pregnant women across a large rural study area in Gaibandha District, northern Bangladesh, 2018-2019. DESIGN: Prospective, longitudinal pregnancy and birth cohort. METHODS: We conducted home visits to enrol pregnant women in the late first or early second trimester (11-17 weeks of gestational age). Women received a quadrivalent seasonal inactivated influenza vaccine at enrolment. Follow-up included up to 13 visits between enrolment and 3 months postpartum. Arsenic was measured in drinking water and maternal urine. Micronutrient deficiencies were assessed using plasma biomarkers. Vaccine-specific antibody titres were measured in maternal and infant serum. Weekly telephone surveillance ascertained acute morbidity symptoms in women and infants. PRELIMINARY RESULTS: We enrolled 784 pregnant women between October 2018 and March 2019. Of 784 women who enrolled, 736 (93.9%) delivered live births and 551 (70.3%) completed follow-up visits to 3 months postpartum. Arsenic was detected (≥0.02 µg/L) in 99.7% of water specimens collected from participants at enrolment. The medians (interquartile ranges) of water and urinary arsenic at enrolment were 5.1 (0.5, 25.1) µg/L and 33.1 (19.6, 56.5) µg/L, respectively. Water and urinary arsenic were strongly correlated (Spearman's ⍴ = 0.72) among women with water arsenic ≥ median but weakly correlated (⍴ = 0.17) among women with water arsenic < median. CONCLUSIONS: The PAIR Study is well positioned to examine the effects of low-moderate arsenic exposure and micronutrient deficiencies on immune outcomes in women and infants. REGISTRATION: NCT03930017.

Cadmium in the hyperaccumulating mushroom Thelephora penicillata: Intracellular speciation and isotopic composition.

Thelephora penicillata is an ectomycorrhizal mushroom that can accumulate extraordinarily high concentrations of Cd, As, Cu, and Zn in its fruit-bodies. To better understand its element accumulation ability, we compared the element concentrations in T. penicillata with 10 distinct ectomycorrhizal mushroom species growing at the same site (Karlina Pila, Czech Republic). On average, T. penicillata accumulated 330, 2130, 26, and 4 times more Cd, As, Cu, and Zn, respectively, than other mushrooms. Size-exclusion chromatography and an electrophoretic analysis of T. penicillata cell extracts indicate that intracellular Cd may be present mainly in >1 kDa, presumably compartmentalized, Cd species, and partially binding with 6-kDa cysteinyl-containing peptide(s) resembling metallothioneins. The cadmium isotopic composition of mushroom fruit-bodies, soil digests, and soil extracts was investigated by thermal ionization mass spectrometry (TIMS) with double spike correction. The isotopic composition (δ114/110Cd) of ectomycorrhizal mushrooms from Karlina Pila varied in a wide range of -0.37 to +0.14 ‰. However, remarkably low δ114/110Cd values were observed in the majority of the investigated mushrooms when compared to the relatively homogeneous Cd isotopic composition of bulk soil (δ114/110Cd = +0.09 ‰) and the comparatively heavy isotopic composition of soil extracts (mean δ114/110Cd values of +0.11 ± 0.01 ‰ and +0.22 ± 0.01 ‰, depending on the extraction method). The isotopic composition of Cd hyperaccumulated in T. penicillata essentially matched the mycoavailable soil Cd fraction. However, most isotopic data indicates isotopic fractionation at the soil/fruit-body interface, which could be of environmental significance.

Corrosion of Passive Aluminum Anodes in a Chloroaluminate Deep Eutectic Solvent for Secondary Batteries: The Bad, the Good, and the Ugly.

The passivity of aluminum is detrimental to its performance as an anode in batteries. Soaking of native oxide-covered aluminum in a chloroaluminate deep eutectic solvent gradually activates the electrode surface, which is reflected in a continuously decreasing open circuit potential. The underlying processes were studied by analyzing the 3 to 7 nm thick layer of native oxide after increasing periods of soaking with secondary neutral mass spectrometry, X-ray photoelectron spectroscopy, and energy-dispersive spectroscopy in a transmission electron microscope. They consistently show permeation of electrolyte species into the layer associated with gradual swelling. After extended periods of soaking at open circuit potentials, local deposits of a range of foreign metals have been found in scanning electron microscopy images of the electrode surface. The pitting corrosion is caused by trace metal ion impurities present in the electrolyte and results in highly nonuniform current density distribution during discharge/charge cycling of battery cells as shown by local deposits of aluminum. The processes during soaking at open circuit potentials have been monitored by electrochemical impedance spectroscopy and could be analyzed by fitting an equivalent circuit model for pitting corrosion.

Trimethylselenonium ion determination in human urine by high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry optimization of the hydride generation step.

This work describes the intricacies of the determination of the trimethylselenonium ion (TMSe) in human urine via high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS). By definition, this technique requires that the separated TMSe can be online converted into a volatile compound. Literature data for the determination of TMSe via the hydride generation technique are contradictory; i.e., some authors claim that direct formation of volatile compounds is possible under reduction with NaBH4, whereas others reported that a digestion step is mandatory prior to conversion. We studied and optimized the conditions for online conversion by varying the mobile phase composition (pyridine, phosphate, and acetate), testing different reaction coils, and optimizing the hydride generation conditions, although technically no hydride (H2Se) is formed but a dimethylselenide (DMSe). The optimized conditions were used for the analysis of 64 urine samples of 16 (unexposed) volunteers and the determination of low amounts of TMSe (LOD = 0.2 ng mL-1). Total (specific gravity-corrected) selenium concentrations in the urine samples ranged from 7.9 ± 0.7 to 29.7 ± 5.0 ng mL-1 for individual volunteers. Four volunteers were characterized as TMSe producers (hINMT genotype GA) and 12 were non-producers (hINMT genotype GG). Urine of TMSe producers contained 2.5 ± 1.7 ng mL-1 of TMSe, compared to 0.2 ± 0.2 ng mL-1 for non-producers.