Influence of Silver Nanoparticles on the Metabolites of Two Transgenic Soybean Varieties: An NMR-Based Metabolomics Approach.

This study investigated the effect of AgNPs and AgNO3, at concentrations equivalent, on the production of primary and secondary metabolites on transgenic soybean plants through an NMR-based metabolomics. The plants were cultivated in a germination chamber following three different treatments: T0 (addition of water), T1 (addition of AgNPs), and T2 (addition of AgNO3). Physiological characteristics, anatomical analyses through microscopic structures, and metabolic profile studies were carried out to establish the effect of abiotic stress on these parameters in soybean plants. Analysis of the 1H NMR spectra revealed the presence of amino acids, organic acids, sugars, and polyphenols. The metabolic profiles of plants with AgNP and AgNO3 were qualitatively similar to the metabolic profile of the control group, suggesting that the application of silver does not affect secondary metabolites. From the PCA, it was possible to differentiate the three treatments applied, mainly based on the content of fatty acids, pinitol, choline, and betaine.

Magnetic carbon nanotubes modified with proteins and hydrophilic monomers: Cytocompatibility, in-vitro toxicity assays and permeation across biological interfaces.

Carbon nanotubes are promising materials for biomedical applications like delivery systems and tissue scaffolds. In this paper, magnetic carbon nanotubes (M-CNTs) covered with bovine serum albumin (M-CNTs-BSA) or functionalized with hydrophilic monomers (M-CNTs-HL) were synthesized, characterized, and evaluated concerning their interaction with Caco-2 cells. There is no comparison between these two types of functionalization, and this study aimed to verify their influence on the material's interaction with the cells. Different concentrations of the nanotubes were applied to investigate cytotoxicity, cell metabolism, oxidative stress, apoptosis, and capability to cross biomimetic barriers. The materials showed cytocompatibility up to 100 µg mL-1 and a hemolysis rate below 2 %. Nanotubes' suspensions were allowed to permeate Caco-2 monolayers for up to 8 h under the effect of the magnetic field. Magnetic nanoparticles associated with the nanotubes allowed estimation of permeation through the monolayers, with values ranging from 0.50 to 7.19 and 0.27 to 9.30 × 10-3 µg (equivalent to 0.43 to 6.22 and 0.23 to 9.54 × 10-2 % of the initially estimated mass of magnetic nanoparticles) for cells exposed and non-exposed to the magnets, respectively. Together, these results support that the developed materials are promising for applications in biomedical and biotechnological fields.

Modern anthropogenic drought in Central Brazil unprecedented during last 700 years.

A better understanding of the relative roles of internal climate variability and external contributions, from both natural (solar, volcanic) and anthropogenic greenhouse gas forcing, is important to better project future hydrologic changes. Changes in the evaporative demand play a central role in this context, particularly in tropical areas characterized by high precipitation seasonality, such as the tropical savannah and semi-desertic biomes. Here we present a set of geochemical proxies in speleothems from a well-ventilated cave located in central-eastern Brazil which shows that the evaporative demand is no longer being met by precipitation, leading to a hydrological deficit. A marked change in the hydrologic balance in central-eastern Brazil, caused by a severe warming trend, can be identified, starting in the 1970s. Our findings show that the current aridity has no analog over the last 720 years. A detection and attribution study indicates that this trend is mostly driven by anthropogenic forcing and cannot be explained by natural factors alone. These results reinforce the premise of a severe long-term drought in the subtropics of eastern South America that will likely be further exacerbated in the future given its apparent connection to increased greenhouse gas emissions.

Recent Advances in Metalloproteomics.

Interactions between proteins and metal ions and their complexes are important in many areas of the life sciences, including physiology, medicine, and toxicology. Despite the involvement of essential elements in all major processes necessary for sustaining life, metalloproteomes remain ill-defined. This is not only owing to the complexity of metalloproteomes, but also to the non-covalent character of the complexes that most essential metals form, which complicates analysis. Similar issues may also be encountered for some toxic metals. The review discusses recently developed approaches and current challenges for the study of interactions involving entire (sub-)proteomes with such labile metal ions. In the second part, transition metals from the fourth and fifth periods are examined, most of which are xenobiotic and also tend to form more stable and/or inert complexes. A large research area in this respect concerns metallodrug-protein interactions. Particular attention is paid to separation approaches, as these need to be adapted to the reactivity of the metal under consideration.

One-point calibration and matrix-matching concept for quantification of potentially toxic elements in wood by LA-ICP-MS.

The aim of this work is to evaluate two quantitative methods, based on the external calibration applied in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis, known as (i) analytical curve and (ii) one-point calibration, using the concept of matrix matching to quantify three potentially toxic elements (PTEs) in wood samples. These can biologically register changes in the abiotic environment and be applied to monitoring climate change or environmental toxicity. In this case, standard sample preparation was evaluated to prepare the standard pellets using Pinus taeda species as a matrix-matching concept. Six pellets of P. taeda, with different Pb, Cd, and Ba concentrations, were prepared to build the analytical curve and one-point calibration strategies. The LA-ICP-MS parameters were optimised for 206Pb, 208Pb, 112Cd, 114Cd, 137Ba, and 138Ba isotope analysis in wood samples. The two calibration strategies provided 74-110% analytical recovery from certified reference materials and similar results to those obtained by ICP-MS through the acid digestion of environmental wood samples from São Paulo City (Brazil). This demonstrated the applicability of the one-point calibration strategy in quantifying PTEs in wood samples, which could be used with environmental analyses. Differences observed between the Ba isotope results obtained via LA-ICP-MS and ICP-MS quantification were related to sampling by LA-ICP-MS and the ICP-MS sample introduction, as well as to laser matrix and transport effects because of the difference between the wood species evaluated.

The microwave-assisted synthesis of silica nanoparticles and their applications in a soy plant culture.

A rapid and environmentally friendly synthesis of thermodynamically stable silica nanoparticles (SiO2-NPs) from heating via microwave irradiation (MW) compared to conductive heating is presented, as well as their evaluations in a soy plant culture. The parameters of time and microwave power were evaluated for the optimization of the heating program. Characterization of the produced nanomaterials was obtained from the dynamic light scattering (DLS) and zeta potential analyses, and the morphology of the SiO2-NPs was obtained by transmission electron microcopy (TEM) images. From the proposed synthesis, stable, monodisperse, and amorphous SiO2-NPs were obtained. Average sizes reported by DLS and TEM techniques were equal to 11.6 nm and 13.8 nm, respectively. The water-stable suspension of SiO2-NPs shows a zeta potential of -31.80 mV, and the homogeneously spheroidal morphology observed by TEM corroborates with the low polydispersity values (0.300). Additionally, the TEM with fast Fourier transform (FFT), demonstrates the amorphous characteristic of the nanoparticles. The MW-based synthesis is 30 times faster, utilizes 4-fold less reagents, and is ca. 18-fold cheaper than conventional synthesis through conductive heating. After the synthesis, the SiO2-NPs were added to the soil used for the cultivation of soybeans, and the homeostasis for Cu, Ni, and Zn was evaluated through the determination of their total contents by inductively coupled plasma mass spectrometry (ICP-MS) in soy leaves and also through bioimages obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Although the results corroborate through both techniques, they also show the influence of these nanoparticles on the elemental distribution of the leaf surface with altered homeostasis of such elements from both transgenic crops compared to the control group.

The stability and function of human cochaperone Hsp40/DNAJA1 are affected by zinc removal and partially restored by copper.

The imbalance in metal homeostasis can be associated with several human diseases, and exposure to increasing concentrations of metals promotes cell stress and toxicity. Therefore, understanding the cytotoxic effect of metal imbalance is important to unravel the biochemical mechanism of homeostasis and the action of potential protective proteins against metal toxicity. Several studies, including gene deletion in yeast, provide evidence indicating the possible indirect involvement of cochaperones from the Hsp40/DNAJA family in metal homeostasis, possibly through modulating the activity of Hsp 70.This work first investigated the effect of zinc and copper on the conformation and function of the human Hsp40 cochaperone DNAJA1, a zinc-binding protein. DNAJA1 was capable to complement the phenotype of a yeast strain deleted of the ydj1 gene, which was more sensitive to the presence of zinc and copper than the wild-type strain. To gain further insight about the role of the DNAJA family in metal binding, the recombinant human DNAJA1 protein was studied. Zinc removal from DNAJA1 affected both its stability and ability to act as a chaperone, i.e., to protect other proteins from aggregation. The reintroduction of zinc restored the native properties of DNAJA1 and, surprisingly, the addition of copper partially restored the native properties.

The role of silver nanoparticles effects in the homeostasis of metals in soybean cultivation through qualitative and quantitative laser ablation bioimaging.

BACKGROUND: Nanoparticles (NPs) are currently found in the world in the form of natural colloids and volcanic ash, as well as in anthropogenic sources, such as nanofertilizers; however, in the literature, there is still a lack of toxicological evidence, risk assessment, and regulations about the use and environmental impact of NPs in the agroindustrial system. Therefore, the aim of this work was to evaluate alterations caused by the presence of AgNPs during the development of soybean plants. METHODS: The BRS232 non-transgenic (NT) soybean plant and 8473RR (TRR) and INTACTA RR2 PRO (TIntacta) transgenic soybean plants were irrigated for 18 days under controlled conditions with deionized water (control), AgNPs, and AgNO3. The isotopes 107Ag+, 55Mn+, 57Fe+, 63Cu+, and 64Zn+ were mapped in leaves, using 13C+ as an internal standard (IS), and carried out using a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) technique with a Nd:YAG (213 nm) laser source in the imagagin mode using the LA-iMageS software and also Mathlab. RESULTS: Leaf images showed a low Ag translocation, indicated by the basal signal of this ion. Additionally, the presence of Ag in the ionic form and as NPs altered the homeostasis of 112Cd+, 64Zn+, 55Mn+, 63Cu+, and 57Fe+ in different ways. Quantitative image analysis was performed for Cu. CONCLUSION: The behavior of TRR and TIntacta plants was different in the presence of ionic silver or AgNPs, confirming that the metabolism of these two plants, despite both being transgenic, are different. Through the images, it was observed that the response of plants was different in the face of the same stress conditions during their development.

There Is Plenty of Room in Plant Science: Nanobiotechnology as an Emerging Area Applied to Somatic Embryogenesis.

Somatic embryogenesis is an essential technology for high productivity in plant culture, and with the advent of nanotechnology, the synergism between these areas could be the answer to developing concepts involving Agriculture 4.0. This perspective permeates both areas, presenting the opportunities and challenges for the consolidation of ideas involving the application of nanoparticles to micropropagation processes (callus induction, preservation, growing, and modification, among others) and also to the production of byproducts (such as biosynthesis of nanoparticles and production of secondary metabolites). Nanotoxicological aspects are also emphasized as well as up-to-date instrumentation involved in these studies.

Single-cell ICP-MS to address the role of trace elements at a cellular level.

The heterogeneity properties shown by cells or unicellular organisms have led to the development of analytical methods at the single-cell level. In this sense, considering the importance of trace elements in these biological systems, the inductively coupled plasma mass spectrometer (ICP-MS) configured for analyzing single cell has presented a high potential to assess the evaluation of elements in cells. Moreover, advances in instrumentation, such as coupling laser ablation to the tandem configuration (ICP-MS/MS), or alternative mass analyzers (ICP-SFMS and ICP-TOFMS), brought significant benefits, including sensitivity improvement, high-resolution imaging, and the cell fingerprint. From this perspective, the single-cell ICP-MS has been widely reported in studies involving many fields, from oncology to environmental research. Hence, it has contributed to finding important results, such as elucidating nanoparticle toxicity at the cellular level and vaccine development. Therefore, in this review, the theory of single-cell ICP-MS analysis is explored, and the applications in this field are pointed out. In addition, the instrumentation advances for single-cell ICP-MS are addressed.

Treatment of migraine in children and adolescents. The state of the art / Tratamento da enxaqueca em crianças e adolescentes. O Estado da arte

Introduction: Headaches and migraine are common in the pediatric population, being one of the most frequent symptoms reported in practice. Additionally, it is a considerably disabling condition, which brings significant burden and impairs several aspects of a child or adolescent's life, such as mental and physical health, executive functioning, school performance. Children and adolescents with migraine have higher risk of psychiatric comorbidities and psychosocial adjustment difficulties, which, in turn, compromise even more patient's well functioning. Objective:The present article provides the clinician with a straightforward and evidence-based approach to migraine treatment in this age group. Comment: Treatment of migraine in children and adolescents requires a systematic and thorough approach. Clinicians should keep in mind the important burden migraine brings to a child's life, thus investigate, and properly manage comorbidities presented. Patient and parents' education is a meaningful part of the treatment. Moreover, non-pharmacological treatments, such as healthy lifestyle habits, behavioral interventions may also play beneficial roles. When preventive treatment is indicated, it should be tailored considering drug's profile of effectiveness and safety, as well as patient's comorbidities. Lack of evidence in this context must not translate in lack of action by the clinician, since there may be a relevant burden associated. Therefore, reasoning for the perspicacious clinician is of fundamental importance and may influence positively the outcomes.

Introdução: Dores de cabeça e enxaqueca são comuns na população pediátrica, sendo um dos sintomas mais frequentes relatados na prática. Além disso, é uma condição consideravelmente incapacitante, que traz sobrecarga significativa e prejudica diversos aspectos da vida de uma criança ou adolescente, como saúde mental e física, funcionamento executivo, desempenho escolar. Crianças e adolescentes com enxaqueca apresentam maior risco de comorbidades psiquiátricas e dificuldades de ajustamento psicossocial, o que, por sua vez, compromete ainda mais o bom funcionamento do paciente. Objetivo: O presente artigo fornece ao médico uma abordagem simples e baseada em evidências para o tratamento da enxaqueca nesta faixa etária. Comente: O tratamento da enxaqueca em crianças e adolescentes requer uma abordagem sistemática e minuciosa. Os médicos devem ter em mente o importante fardo que a enxaqueca traz à vida de uma criança, investigando e gerenciando adequadamente as comorbidades apresentadas. A educação do paciente e dos pais é uma parte significativa do tratamento. Além disso, os tratamentos não farmacológicos, como hábitos de vida saudáveis ​​e intervenções comportamentais, também podem desempenhar papéis benéficos. Quando indicado tratamento preventivo, este deve ser adaptado considerando o perfil de efetividade e segurança do medicamento, bem como as comorbidades do paciente. A falta de evidências neste contexto não deve traduzir-se em falta de ação por parte do médico, uma vez que pode haver um ónus relevante associado. Portanto, o raciocínio do clínico perspicaz é de fundamental importância e pode influenciar positivamente os resultados.

Unravelling the genetic potential for hydrocarbon degradation in the sediment microbiome of Antarctic islands.

Hydrocarbons may have a natural or anthropogenic origin and serve as a source of carbon and energy for microorganisms in Antarctic soils. Herein, 16S rRNA gene and shotgun sequencing were employed to characterize taxonomic diversity and genetic potential for hydrocarbon degradation of the microbiome from sediments of sites located in two Antarctic islands subjected to different temperatures, geochemical compositions, and levels of presumed anthropogenic impact, named: Crater Lake/Deception Island (pristine area), Whalers Bay and Fumarole Bay/Deception Island (anthropogenic-impacted area), and Hannah Point/Livingston Island (anthropogenic-impacted area). Hydrocarbon concentrations were measured for further correlation analyses with biological data. The majority of the hydrocarbon-degrading genes were affiliated to the most abundant bacterial groups of the microbiome: Proteobacteria and Actinobacteria. KEGG annotation revealed 125 catabolic genes related to aromatic hydrocarbon (styrene, toluene, ethylbenzene, xylene, naphthalene, and polycyclic hydrocarbons) and aliphatic (alkanes and cycloalkanes) pathways. Only aliphatic hydrocarbons, in low concentrations, were detected in all areas, thus not characterizing the areas under study as anthropogenically impacted or nonimpacted. The high richness and abundance of hydrocarbon-degrading genes suggest that the genetic potential of the microbiome from Antarctic sediments for hydrocarbon degradation is driven by natural hydrocarbon occurrence.

Speciomics as a concept involving chemical speciation and omics.

The study of chemical speciation and the refinement and expansion of omics-based methods are both consolidated and highly active research fields. Although well established, such fields are extremely dynamic and are driven by the emergence of new strategies and improvements in instrumentation. In the case of omics-based studies, subareas including lipidomics, proteomics, metallomics, metabolomics and foodomics have emerged. Here, speciomics is being proposed as an "umbrella" term, that incorporates all of these subareas, to capture studies where the evaluation of chemical species is carried out using omics approaches. This paper contextualizes both speciomics and the speciome, and reviews omics applications used for species identification through examination of proteins, metalloproteins, metabolites, and nucleic acids. In addition, some implications from such studies and a perspective for future development of this area are provided. SIGNIFICANCE: The synergic effect between chemical speciation and omics is highlighted in this work, demonstrating an emerging area of research with a multitude of possibilities in terms of applications and further developments. This work not only defines and contextualizes speciomics and individual speciomes, but also demonstrates with some examples the great potential of this new interdisciplinary area of research.

Trace element homeostasis in the neurological system after SARS-CoV-2 infection: Insight into potential biochemical mechanisms.

BACKGROUND: Several studies have suggested that COVID-19 is a systemic disease that can affect several organs, including the brain. In the brain, specifically, viral infection can cause dyshomeostasis of some trace elements that promote complex biochemical reactions in specialized neurological functions. OBJECTIVE: Understand the neurovirulence of SARS-CoV-2 and the relationship between trace elements and neurological disorders after infection, and provide new insights on the drug development for the treatment of SARS-CoV-2 infections. METHODS: The main databases were used to search studies published up September 2021, focusing on the role of trace elements during viral infection and on the correct functioning of the brain. RESULTS: The imbalance of important trace elements can accelerate SARS-CoV-2 neurovirulence and increase the neurotoxicity since many neurological processes can be associated with the homeostasis of metal and metalloproteins. Some studies involving animals and humans have suggested the synapse as a vulnerable region of the brain to neurological disorders after viral infection. Considering the combined evidence, some mechanisms have been suggested to understand the relationship between neurological disorders and imbalance of trace elements in the brain after viral infection. CONCLUSION: Trace elements play important roles in viral infections, such as helping to activate immune cells, produce antibodies, and inhibit virus replication. However, the relationship between trace elements and virus infections is complex since the specific functions of several elements remain largely undefined. Therefore, there is still a lot to be explored to understand the biochemical mechanisms involved between trace elements and viral infections, especially in the brain.

Associated Factors of Attention-Deficit/Hyperactivity Disorder Diagnosis and Psychostimulant Use: A Nationwide Representative Study.

BACKGROUND: Connections between epidemiological findings and children's and adolescents' mental health policies have not been properly made in Brazil, and such nationwide studies are scarce. This epidemiological study (1) estimated the prevalence and predictors of parent-reported attention-deficit/hyperactivity disorder (ADHD) (ADHD-report), (2) estimated the probable diagnosis and risk of ADHD based on Diagnostic and Statistical Manual of Mental Disorders, 5th edition, criteria (ADHD-probable), and (3) estimated current psychostimulant use (ADHD-pst) in a representative nationwide sample of Brazilian school-aged children and adolescents. METHODS: Data were obtained from 7114 school-aged children (49.9% boys) from 87 cities in 18 Brazilian states. Parents and teachers were interviewed using psychometrically sound questionnaires. Data and codes are available. RESULTS: The prevalence of ADHD-report, ADHD-probable, and ADHD-pst were 7.1%, 3.9%, and 1.9%, respectively. The agreement was low between ADHD-probable and ADHD-report (22.6%) and between ADHD-report and ADHD-pst (15.6%). Logistic regression revealed that predictors of all three categories were male gender (odds ratio [OR] = 1.71, 2.32, and 1.96, respectively), divorced parents (OR = 1.47, 1.65, and 1.68, respectively), and below-expectation school performance (OR = 3.1, 13.74, and 3.95, respectively). Socioeconomic status was a significant predictor of ADHD-report, and participants from lower classes were less frequently diagnosed with ADHD than their peers from upper classes (OR = 0.57, 95% confidence interval = 0.37-0.88, P = 0.012). CONCLUSIONS: The present findings provide an accurate description of ADHD in Brazil. We suggest disparities in agreement between report, risk, and psychostimulant use among children and adolescents and discrepancies between socioeconomic classes concerning the prevalence of an ADHD diagnosis.

Psychometric properties and clinical utility of the executive function inventory for children and adolescents: a large multistage populational study including children with ADHD.

Executive functions (EF) are a set of high order mental abilities that regulate cognition, emotions, and behavior. This study aims to report the construction and validation of a rating scale instrument for EF in children and adolescents aged from 5 to 18 years (EFICA), as well as to report the results of a comparison between children with ADHD and their peers without it. Thus, we conducted a population-based cross-sectional study relying on a sample composed of 3,284 typical children and adolescents accessed to study the psychometric properties of the parents' inventory (EFICA-P) and the teacher's inventory (EFICA-T) within a Structural Equation Modeling framework (SEM). Exploratory and confirmatory analyses were fitted, as well as the Cronbach's alpha and the McDonald's omega reliability indices. The known-groups method was carried out by independent Welch t-tests between untreated ADHD children and their peers. We concluded that the parents' inventory is composed of three dimensions (Cool Index 1, Cool Index 2, and Hot Index): χ2 (1,649) = 4,607.852 p < .01, CFI = .965, TLI .963, RMSEA = .053, whereas the teachers´ inventory is composed of two dimensions (Cool Index and Hot Index): χ2 (1,273) = 5,158.240, p < .01, CFI = .991, TLI = .991, RMSEA = .077. The internal consistency of both inventories was >.9. Significant differences between the ADHD groups were found in all domains accessed. These findings indicate that both inventories have a high degree of validity regarding their internal structures, as well as supporting their clinical utility.

Trace elements distribution in tropical tree rings through high-resolution imaging using LA-ICP-MS analysis.

BACKGROUND: The distribution of trace elements in tree rings although poorly known may be useful to better understand environmental changes, pollution trends, long-term droughts, forest dieback processes, and biology of trees. METHOD: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used for imaging micronutrients and potentially toxic elements distribution, allowing the investigation of trace elements at high spatial resolution within the tree rings. To ensure a more efficient determination of micronutrients and potentially toxic elements, LA-ICP-MS instrumental conditions were optimized and carbon, a major element in wood, is used as an internal standard during analysis to correct for random fluctuations. RESULTS: Spatial distributions maps of Ba, Cu, Fe, Mn, Ni, and Pb in growth layers of six tropical tree species were built-up using the LA-iMageS software, namely: Amburana cearensis (Fabaceae), Cedrela fissilis (Meliaceae), Hymenaea courbaril (Fabaceae), Maclura tinctoria (Moraceae), Parapiptadenia zehntneri (Fabaceae), Peltogyne paniculata (Fabaceae). A correlation between the trace element composition and different cell types (parenchyma, fiber, and vessel) was distinctly observed. It was observed a general pattern of Ba, Cu, Ni, Mn, and Pb accumulation mainly in the axial parenchyma and vessels. But the elemental composition of xylem cells is strongly species dependent. The multivariate analysis also points to a distinct accumulation of minerals between heartwood and sapwood in the same species. CONCLUSIONS: Imaging both essential and deleterious element distributions in the tree rings may improve visualization and can effectively contribute to understanding the lifetime metabolism of trees and evaluating the effects of environmental changes related to climatic seasonality, pollution, and future paleoclimate reconstructions.

Distribution, accumulation and speciation of selenium at the different growth stages of four garlic clones.

Selenium (Se) is an essential micronutrient for humans. Garlic (Allium sativum L.) metabolises Se into important Se-amino acids like Se-methylselenocysteine (Se-MetSeCys), precursor of methylselenol, an active species for cancer prevention. Therefore, the Se accumulation and speciation in garlic were studied to evaluate their relations with growth stages and types of plant clones. Four garlic clones (Nieve INTA, Union FCA, Gostoso INTA and Rubí INTA) were fortified with a Se solution (169 g Se L-1). The association of Se to different molecular weight fractions was evaluated by size-exclusion chromatography coupled to inductively coupled plasma mass spectrometry (SEC-ICP-MS) detection. Also, anion exchange chromatography (AEC-ICP-MS) was used for the determination of Se-amino acids, while their identification was performed by ESI-MS/MS. The Se was incorporated into high (7-5 kDa) and low (2-4 kDa) molecular weight fractions. The presence of Se-MetSeCys was observed mostly. Se-MetSeCys increased in bulbs to a maximum value but increased, then decreased, in leaves and roots. The Se-organic species were mostly found in bulbs in the last growth stage. Garlic showed a significant ability to accumulate and metabolise Se, specially, the red clones (Gostoso INTA and Rubí INTA). Also, this work suggests that this plant may become an attractive source of Se-amino acids with important biological properties.

Resilience and vulnerability in adolescents with primary headaches: A cross-sectional population-based study.

BACKGROUND: A scarcity of studies on the role of resilience resources (RRs) and vulnerability risk (VR) in children and adolescents with primary headache hampers the development of a risk-resilience model for pediatric headaches. OBJECTIVE: To examine the extent to which headache frequency and diagnosis are associated with RRs and VR and explore possible predictors of low RRs and high VR in a cross-sectional population-based study in adolescents. METHODS: This is a cross-sectional population study conducted in a small city in Brazil (Delfinópolis). Consents and analyzable data were obtained from 339/378 adolescents (89.7%). RRs and VR were assessed using the validated Brazilian version of the Resiliency Scales for Children and Adolescents, completed by the adolescents. Parents filled a structured questionnaire assessing sociodemographic and headache characteristics, as well as the Brazilian-validated version of the Strengths and Difficulties Questionnaire added to the impact supplement to evaluate the adolescent's psychosocial adjustment skills. Teachers completed a structured questionnaire about the students' school performance. RESULTS: A higher frequency of headache was associated with lower RRs (F3,335  = 2.99, p = 0.031) and higher VR (F3,335  = 4.05, p = 0.007). Headache diagnosis did not significantly influence the risk of having lower RRs or higher VR. In the exploratory analyses, females (OR 3.07; 95% CI: 1.16-9.3) and individuals with psychosocial adjustment problems (OR 7.5; 95% CI: 2.51-22.4) were predictors of low RRs, and prenatal exposure to tobacco (OR 5.6; 95% CI: 1.57-20.9) was a predictor of high VR in adolescents with primary headache. CONCLUSIONS: The risk of low RRs and high VR was associated with a higher headache frequency, but not with headache diagnosis. These findings may contribute to the development of a risk-resilience model of headaches in the pediatric population and help identify novel targets and develop effective resources for successful interventions.

Evaluating the total gold concentration in metallic nanoparticles with a high content of organic matter through microwave-assisted decomposition platform and plasma-based spectrometric techniques (ICP-MS and ICP OES).

We report a complete set of strategies for characterization and an accurate determination of gold in metallic nanoparticles. For this, gold nanorods (AuNR) were synthesized by using the surfactant hexadecyltrimethylammonium bromide (CTAB) as the stabilizer and shape-directing agent. The surfactant CTAB forms a bilayer structure around the nanoparticles and became a challenge for the development of the microwave-assisted decomposition of the AuNR colloid. The bilayer structure of CTAB prevents the Au3+ release for the acidic media during the decomposition procedure. To overcome this limitation, a combination of low sample volume consumption (only 200 µL), an acidic mixture of reverse aqua regia (1:3 v/v, HCl:HNO3), and sulfuric acid, and a microwave program was used. The gold quantification by ICP-MS and checked through the ICP OES, demonstrated that the seed-mediated growth method used for the AuNR synthesis has a high yield, presenting ca. 100% of gold content (ca. 100 mg L-1 of gold concentration) in the post-synthesis colloid (AuNR-total) as well as in the colloid after a washing step (AuNR-res). The microwave-assisted decomposition procedure also demonstrated to be efficient in the acidic decomposition of the gold-silver core-shell nanoparticle (Au@AgNR), which presents a high content of polyvinylpyrrolidone (PVP) (Mw ~55000 g mol-1) acting as a stabilizer, in addition to the matrix with CTAB. The results demonstrated an accurate recovery of ca. 100% of gold content for the Au@AgNR regarding the gold nanorod before the growth of the silver shell (AuNR_Core). The proposed microwave-assisted decomposition platform demonstrated to be an efficient, reliable, and robust characterization tool for the gold quantification in metallic nanoparticles, presenting no interference of the complex matrix with high organic content.