Understanding the chemical and mineralogical composition of commercial henna and jagua tattoos and dyes-a multi-analytical approach.

Temporary tattoos and dyes constitute a great analytical challenge in relation to the regulatory control of their ingredients. Most of these commercial products are not labeled according to their content and their chemical nature is highly diverse. Therefore, it is necessary to analyze these complex samples to evaluate the potential presence of metallic impurities, to ensure the safety of cosmetic products contributing to health protection. This study proposes a multi-analytical methodology, which includes handheld X-ray fluorescence (h-XRF) and X-ray diffraction (XRD), complemented by variable pressure scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (VP-SEM-EDS) to fully characterize 34 commercial samples of jagua and henna tattoos and dyes. The approach allowed the identification of the main constituents providing complementary compositional data and differences between sample types were established. In addition, information on the degree of natural pigments homogeneity was also obtained. The results' discussion considering the current European cosmetics regulation may be useful to support the drafting of safety requirements and specific regulation.

Toxic levels of manganese in an acidic Cambisol alters antioxidant enzymes activity, element uptake and subcellular distribution in Triticum aestivum.

In the Montado system, in Portuguese Alentejo region, some Eutric Cambisols are known to promote manganese (Mn) toxicity in wheat. Variation on bioavailable Mn concentration depends on soil acidity, which can be increased by natural events (e.g. waterlogging) or human activity (e.g. excess use of chemical fertilizers). The effect of increasing soil Mn on crop element uptake, element distribution and oxidative stress was evaluated on winter wheat (Triticum aestivum). Plants were grown for 3 weeks in an acidic Cambisol spiked with increasing Mn concentrations (0, 45.2 and 90.4 mg MnCl2/Kg soil). Calcium (Ca), phosphorus (P), magnesium (Mg) and Mn were quantified in the soil solution, root and shoot tissues and respective subcellular fractions. The activity of the antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) were determined in extracts of wheat shoots and roots. Overall, increase in soil bioavailable Mn inhibited the uptake of other elements, increased the Ca proportion in the root apoplast, promoted the translocation of Mn and P to shoot tissues and increased their proportion in the shoot vacuoles. Wheat roots showed greater antioxidant enzymes activities than shoots. These activities decreased at the highest soil Mn concentration in both plant parts. Wheat roots appear to be more sensitive to oxidative stress derived from excess soil Mn and promote Mn translocation and storage in shoot vacuoles, probably in Mn and P complexes, as a detoxification strategy. Improvement in wheat production, in acidic soils, may rely on the enhancement of its Mn detoxification strategies.

A Micro-Analytical Study of the Scarabs of the Necropolis of Vinha das Caliças (Portugal).

Five scarabs and one scaraboid found in Vinha das Caliças 4 (Beja, Portugal) were analyzed using a micro-analytical methodology in order to determine their mineralogical and chemical composition. Microstructural characterization and chemical analysis revealed that all were composed of a white body of crushed feldspathic sand covered by a lead-rich, alkaline-depleted silicate blue-green glaze showing evident signs of glass deterioration. Variable pressure scanning electron microscopy with X-ray energy dispersive spectrometry, handheld X-ray fluorescence spectroscopy, and micro X-ray diffraction results show that blue-green color of the glaze was produced by using copper ions (Cu2+) in conjunction with the lead antimonate bindheimite, a yellow-colored opacifier. The introduction of small amounts of tin in the structure of bindheimite enabled the production of a ternary Pb-Sb-Sn oxide. Tin, which was most likely added with the copper source (bronze scrapings), is known to facilitate the crystallization of bindheimite. The results are consistent with the five scarabs and one scaraboid being manufactured in Egypt. This study, the first archeometric study of scarabs found in the Iberian peninsula, has greatly contributed to the understanding of the influence of the Eastern and Central Mediterranean world in the Southwestern Iberia during the first millennium B.C.

Stereoselective Reduction of Imines with Trichlorosilane Using Solid-Supported Chiral Picolinamides.

The stereoselective reduction of imines with trichlorosilane catalyzed by chiral Lewis bases is a well-established procedure for the synthesis of enantio-enriched amines. Five supported cinchona-based picolinamides have been prepared and their activity tested in a model reaction. The comparison of different supporting materials revealed that polystyrene gave better results than silica in terms of stereoselectivity. The applicability of the solid-supported catalyst of choice to the reduction of different imines was also demonstrated. Additionally, for the first time, a catalytic reactor containing a polymer-immobilized chiral picolinamide has been employed for the stereoselective reduction of imines with trichlorosilane under continuous flow conditions.

Mycorrhizal Colonization of Wheat by Intact Extraradical Mycelium of Mn-Tolerant Native Plants Induces Different Biochemical Mechanisms of Protection.

Soil with excess Mn induces toxicity and impairs crop growth. However, with the development in the soil of an intact extraradical mycelia (ERM) from arbuscular mycorrhizal fungi (AMF) symbiotic to native Mn-tolerant plants, wheat growth is promoted due to a stronger AMF colonization and subsequent increased protection against Mn toxicity. To determine the biochemical mechanisms of protection induced by this native ERM under Mn toxicity, wheat grown in soil from previously developed Lolium rigidum (LOL) or Ornithopus compressus (ORN), both strongly mycotrophic plants, was compared to wheat grown in soil from previously developed Silene gallica (SIL), a non-mycotrophic plant. Wheat grown after LOL or ORN had 60% higher dry weight, ca. two-fold lower Mn levels and almost double P contents. Mn in the shoots was preferentially translocated to the apoplast along with Mg and P. The activity of catalase increased; however, guaiacol peroxidase (GPX) and superoxide dismutase (SOD) showed lower activities. Wheat grown after ORN differed from that grown after LOL by displaying slightly higher Mn levels, higher root Mg and Ca levels and higher GPX and Mn-SOD activities. The AMF consortia established from these native plants can promote distinct biochemical mechanisms for protecting wheat against Mn toxicity.

The chemistry behind the body art: unveiling the elemental profile and heavy metal content of natural tattoos and dyes by ICP-MS.

Temporary tattoos and dyes are increasing popularity as an alternative to permanent ones. However, knowledge on its elementary composition is scarce and, this scientific gap can potentially make them a source of heavy metal exposure on humans. The present research aimed to explore the possibility of using the inorganic chemical signature to characterize natural pigments-based products and to evaluate the heavy metal content in jagua temporary tattoos and henna temporary hair dyes and tattoos. Thirty-four different samples of commercial products were analyzed for the presence and quantity of eleven trace elements (Al, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Ba, and Pb) by inductively coupled plasma mass spectrometry (ICP-MS). The overall mean concentrations varied between 0.02 and 973 µg g-1 in solid samples or 0.01-1878 µg g-1 for paste ones, wherein potential fake products were uncovered. None of the 34 samples considered comply with the current European Cosmetics Regulation. Samples were differentiated according to their Cr, Zn, Ba, and Pb content. The overall results revealed highly variable levels in the investigated samples, which leads us to suggest detailed quality controls of these materials, due the fact that their continued use can origin potential threat to human health.

Spatial and Temporal Distribution of the Multi-element Signatures of the Estuarine Non-indigenous Bivalve Ruditapes philippinarum.

Filter-feeder bivalves such as non-indigenous Ruditapes philippinarum absorb and accumulate metals, resulting in multi-element profiles. The goal of this study was to analyse spatial and temporal distributions of the multi-element signatures in R. philippinarum populations of the Tagus and Sado estuaries (SW coast, Portugal). The clam and sediment samples were collected at three sampling sites in each estuary, on three sampling occasions, and the analysis were done by ICP-MS (inductively coupled plasma mass spectrometry). The chemical elements were categorized according to estuarine geomorphology sources (Se, Co, Ni and Cu), elements with function in metabolic processes of the clams (Mn, Fe, Zn and Cr) and elements derived from the anthropogenic inputs (As, Pb and Cd). Zinc, Co, Ni and Pb were the main contributors for the chemical signatures of Tagus estuary populations, whilst for the Sado estuary populations were Cu, Fe, Cr, As and Cd. They were representative of all elemental categories and proved to be spatial and temporal habitat discriminators of bivalves' estuarine populations. The multi-element signatures of R. philippinarum as a natural tag derived from the physical and chemical conditions of its habitat is a potential rapid tool to use in ecological monitoring and habitat assessment.

A multi-analytical characterization of fourteenth to eighteenth century pottery from the Kongo kingdom, Central Africa.

Pottery traditions reflect the socioeconomic framework of past cultures, while the spatial distribution of pottery indicates exchange patterns and interaction processes. Material and earth sciences are employed here to determine raw material sourcing, selection and processing. The Kongo kingdom, internationally renowned since the late fifteenth century, is one of the most famous precolonial states in Central Africa. Despite the large number of historical studies relying on African and European oral and written chronicles, there are still considerable gaps in our current understanding of this political unit. Here, we provide new insights into pottery production and circulation within the Kongo kingdom. Implementing a multi-analytical approach, namely XRD, TGA, petrographic analysis, XRF, VP-SEM-EDS and ICP-MS, on selected samples, we determined their petrographic, mineralogical and geochemical signatures. Our results allowed us to correlate the archaeological objects to naturally occurring materials and to establish ceramic traditions. We identified production templates, exchange patterns, distribution of high-quality goods and interaction processes through technological knowledge transmission. Our results demonstrate that political centralisation in the Lower Congo region of Central Africa had a direct impact on pottery production and circulation. We expect our study to provide a sound basis for further comparative research to contextualise the region.

Transcriptome Analysis of Wheat Roots Reveals a Differential Regulation of Stress Responses Related to Arbuscular Mycorrhizal Fungi and Soil Disturbance.

Symbioses with soil microorganisms are central in shaping the diversity and productivity of land plants and provide protection against a diversity of stresses, including metal toxicity. Arbuscular mycorrhizal fungi (AMF) can form extensive extraradical mycelial networks (ERM), which are very efficient in colonizing a new host. We quantified the responses of transcriptomes of wheat and one AMF partner, Rhizoglomus irregulare, to soil disturbance (Undisturbed vs. Disturbed) and to two different preceding mycotrophic species (Ornithopus compressus and Lolium rigidum). Soil disturbance and preceding plant species engender different AMF communities in wheat roots, resulting in a differential tolerance to soil manganese (Mn) toxicity. Soil disturbance negatively impacted wheat growth under manganese toxicity, probably due to the disruption of the ERM, and activated a large number of stress and starvation-related genes. The O. compressus treatment, which induces a greater Mn protection in wheat than L. rigidum, activated processes related to cellular division and growth, and very few related to stress. The L. rigidum treatment mostly induced genes that were related to oxidative stress, disease protection, and metal ion binding. R. irregulare cell division and molecular exchange between nucleus and cytoplasm were increased by O. compressus. These findings are highly relevant for sustainable agricultural systems, when considering a fit-for-purpose symbiosis.

Natural limestone discolouration triggered by microbial activity-a contribution.

Colour is a major argument that drives the decision of an architect in a specific architecture project and one of the most important characteristics and perceptible aspects of natural building stones. "Blue" limestones are building rocks, with different geological ages, typically used in several countries, and are known for their vulnerability to alteration, which causes colour change and the occurrence of unaesthetic patterns. Owing to this vulnerability, the conservation-restoration works in monuments, or new buildings constructed with "blue" limestone is extremely costly. Considering that the main limitation of this lithological variation is the chromatic change, a multidisciplinary approach was envisaged in this study to allow a closer insight into the chemical and mineralogical alterations and the microbial communities. Results obtained suggest that the inorganic alteration in the "blue" limestone may create favourable conditions for microbial growth and could lead to an increment in deterioration process.