Hiram Castillo-Michel

European Synchrotron Radiation Facility | ESRF · Division of Experiments

The term sample dependence describes the troublesome tendency of nominally equivalent samples to exhibit different physical properties. High entropy oxides (HEOs) are a class of materials where sample dependence has the potential to be particularly profound due to their inherent chemical complexity. In this work, we prepare a spinel HEO of identica...

The opacity/transparency, color, and production of designs in Changsha ware, a Tang dynasty Chinese stoneware renowned for its polychromy and pioneering high‐temperature red glaze, are studied by analyzing the composition, micro/nanostructure, and copper/iron speciation. The results shed new light on some of the most debated questions about Changsh...

Plants adapt to fluctuating environmental conditions by adjusting their metabolism and gene expression to maintain fitness¹. In legumes, nitrogen homeostasis is maintained by balancing nitrogen acquired from soil resources with nitrogen fixation by symbiotic bacteria in root nodules2–8. Here we show that zinc, an essential plant micronutrient, acts...

Titanium dioxide nanoparticles are used in different processes, derived from this their presence in wastewater is common, concentrating in residual sludge. These residues are used as agricultural soil improvers, being a source of crop exposure. In this study, the effect of TiO2-NPs (450, 900, and 1800 mg L-1) on the germination of alfalfa, tomato,...

Here, isotopically labeled 68ZnO NPs (ZnO NPs) and 68ZnO NPs with a thin 68Zn3(PO4)2 shell (ZnO_Ph NPs) were foliarly applied (40 μg Zn) to pepper plants (Capsicum annuum) to determine the effect of surface chemistry of ZnO NPs on the Zn uptake and systemic translocation to plant organs over 6 weeks. Despite similar dissolution of both Zn-based NPs...

The stomatopod Odontodactylus scyllarus uses weaponized club-like appendages to attack its prey. These clubs are made of apatite, chitin, amorphous calcium carbonate, and amorphous calcium phosphate organized in a highly hierarchical structure with multiple regions and layers. We follow the development of the biomineralized club as a function of ti...

Exposures to exogenous particles is of increasing concern to human health. Characterising the concentrations, chemical species, distribution, and involvement of the stimulus with the tissue microanatomy is essential in understanding the associated biological response. However, no single imaging technique can interrogate all these features at once w...

This paper presents the application of laboratory X-ray Absorption Fine Structure Spectroscopy (XAFS) in the field of iron coordination chemistry, especially for compounds with larger organic ligands and usually low...

TiO2 nanoparticles (TiO2-NPs) have a wide range of industrial applications (paintings, sunscreens, food and cosmetics) and is one of the most intensively used nanomaterials worldwide. Leaching from commercial products TiO2-NPs are predicted to significantly accumulate in wastewater sludges, which are then often used as soil amendment. In this work,...

Despite the increasing attention given to the impacts of nanoplastics in terrestrial environments, there is limited data about the effects on plants, and the quantitative information on uptake. In the present study, wheat plants grown in hydroponics were exposed to Pd-doped nanoplastics. This allowed us to quantify nanoplastics uptake and transloca...

Correction for ‘Spatiotemporal distribution and speciation of silver nanoparticles in the healing wound’ by Marco Roman et al. , Analyst , 2020, 145 , 6456–6469, DOI: 10.1039/D0AN00607F.

Carbon nanotubes (CNTs) and titanium dioxide nanoparticles (TiO2-NPs) are among the most used nanomaterials (NMs). However, their impacts especially on the terrestrial ecosystems and on plants are still controversial. Apart...

Copper oxide nanoparticles (CuO-NPs) have been increasingly released in aquatic ecosystems over the past decades as they are used in many applications. Cu toxicity to different organisms has already been highlighted in the literature, however toxicity mechanisms of the nanoparticulate form remain unclear. Here, we investigated the effect, transfer...

Biosolids (Bs) for use in agriculture are an important way for introducing and transferring TiO2 nanoparticles (NPs) to plants and food chain. Roots of Pisum sativum L. plants grown in Bs-amended soils spiked with TiO2 800 mg/kg as rutile NPs, anatase NPs, mixture of both NPs and submicron particles (SMPs) were investigated by Transmission Electron...

Microplastic and nanoplastic contamination is widespread and affects aquatic and terrestrial ecosystems. Photosynthetic organisms are present in both media, they are primary producers, sink for CO2, and they represent a major point of entry in the food chain. Here, the current knowledge on the fate and impacts of microplastics and nanoplastics in i...

We investigated population structure and arsenic bioaccumulation and distribution in zooplankton inhabiting highly contaminated freshwater with arsenic. We collected water and zooplankton samples over a 4 year period, determined environmental temperature as well as water temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), o...

Micro - X-ray Absorption Near Edge Structure (μXANES) at the Fe K-edge of biological tissues after admission of superparamagnetic iron oxide nanoparticles (SPIONs) has been used to monitor the iron oxidation state in the nanoparticles and in the native tissues. It was found that μXANES technique with submicron spatial resolution is sensitive enough...

Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradie...

The increasing number of patents suggests that the use of nanoparticles (NP) in agriculture will continue to grow in the future. Properties associated with nanosized objects might be desirable, but may pose a threat to the environment since the fate of nanomaterials is poorly understood. Seed treatment is an extensive practice to provide micronutri...

This work investigates the mechanisms determining Cr speciation and availability in two different soils polluted with two chromium sources (an industrial sludge, highly polluted with Cr, and Cr(VI) solution) and the influence of these parameters on the recovery of the soil functions related with biological quality and plant growth. The experiment w...

This work investigates the mechanisms determining Cr speciation and availability in two different soils polluted with two chromium sources (an industrial sludge, highly polluted with Cr, and Cr(VI) solution) and the influence of these parameters on the recovery of the soil functions related with biological quality and plant growth. The experiment w...

Zinc speciation, chemical forms, and phytoavailability were determined within mine tailings and soil samples from a historical mining site in the Xichú district, central Mexico. For this purpose, species determination and phase mapping were conducted using XAS, μ-XRF, and μ-XRD, and chemical extraction was performed to assess chemical forms and phy...

The rapid overexploitation of natural resources for energy use, climate change and environmental degradation are one of the major threats for societies around the globe. Here we discuss the European Synchrotron Radiation Facility instruments tailored specifically for energy and environmental research in order to tackle these major challenges. Sever...

The medical application of nanomaterials is growing fast. Amongst the most widely used, silver nanoparticles are antimicrobial agents whose key application is the care of burns and chronic wounds. Still, their absorption, distribution, metabolism and excretion behavior in vivo has not yet been systematically investigated. We collected full-profile...

Background: Phosphorus (P) deficiency limits crop production worldwide. Crops differ in their ability to acquire and utilise the P available. The aim of this study was to determine root traits (root exudates, root system architecture (RSA), tissue-specific allocation of P, and gene expression in roots) that (a) play a role in P-use efficiency and...

Iron is an essential cofactor for symbiotic nitrogen fixation, required by many of the enzymes involved, including signal transduction proteins, O2 homeostasis systems, and nitrogenase itself. Consequently, host plants have developed a transport network to deliver essential iron to nitrogen‐fixing nodule cells. Ferroportin family members in model l...

The giant gypsum crystals of Naica cave have fascinated scientists since their discovery in 2000. Human activity has changed the microclimate inside the cave, making scientists wonder about the potential environmental impact on the crystals. Over the last 9 years, we have studied approximately 70 samples. This paper reports on the detailed chemical...

Engineering protein-based biomaterials is extremely challenging in bioelectronics, medicine and materials science, as mechanical, electrical and optical properties need to be merged to biocompatibility and resistance to biodegradation. An effective strategy is the engineering of physiological processes in situ, by addition of new properties to endo...

Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires relatively large levels of transition metals. These elements are cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vascul...

Phosphorus (P) resource availability is declining and the efficiency of applied nutrients in agricultural soils is becoming increasingly important. This is especially true for P fertilizers from recycled materials, which often have low plant availability. Specific co-fertilization with ammonium can enhance P plant availability in soils amended with...

Understanding how essential and toxic elements are distributed in cereal grains is a key to improving the nutritional quality of cereal-based products. The main objective of this work was to characterize the distribution of Cd and of nutrients (notably Cu, Fe, Mn, P, S and Zn) in the durum wheat grain. Laser ablation inductively coupled mass spectr...

In wheat (Triticum aestivum L.), the awns—the bristle-like structures extending from lemmas—are photosynthetically active. Compared to awned cultivars, awnletted cultivars produce more grains per unit area and per spike, resulting in significant reduction in grain size, but their mineral element composition remains unstudied. Nine awned and 11 awnl...

It has been extensively studied in a context of chemical resistance, but remains poorly studied in response to chemical exposure in a context of global change. As aquatic ecosystems are particularly affected by environmental changes, we aimed to study how genotypic variability could inflect the sensitivity of aquatic plants to chemicals. Seven geno...

Mixotrophic micro‐organisms are able to use organic as well as inorganic carbon sources and, thus, play an essential role in the biogeochemical carbon cycle. In aquatic ecosystems, the alteration of CO2 fixation by toxic metals such as cadmium ‐ classified as a priority pollutant ‐ could contribute to the unbalance of the carbon cycle. In consequen...

Phenolic compounds (PC) have been proposed as natural antioxidant agents that protect cells against oxidative stress-related diseases. Nonetheless, their low bioavailability forecasts controversy about mechanisms on their in vivo scavenging activity against reactive oxygen species (ROS). It has been proposed that PC reduce directly ROS concentratio...

Many attempts have been made to synthesize cadmium-free quantum dots (QDs) using nontoxic materials, while preserving their unique optical properties. Despite impressive advances, gaps in knowledge of their intracellular fate, persistence and excretion from the targeted cell or organism still exist, precluding clinical applications. In this study,...

Background: Allergic reactions to tattoos are amongst the most common side effects occurring with this permanent deposition of pigments into the dermal skin layer. The characterization of such pigments and their distribution has been investigated in recent decades. The health impact of tattoo equipment on the extensive number of people with inked...

Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires of relatively large levels of transition metals. These elements act as cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the...

Significance Silver nanowires are a type of novel fiber that are likely to have wide application in consumer electronics but that can also carry risk for cell internalization and toxicity. Here, we show that silver nanowire toxicity can be greatly diminished by reducing nanowire diameter without affecting device performance. X-ray microscopy and su...

Sulfur (S) and phosphorus (P) are essential elements for plant growth and physiological functioning. Their deficiency can limit N2 fixation and nodule development in nodulated legumes. The location of S within nodule tissues could provide insights into S metabolism and its little-known relationship with N2 fixation. Determinate and indeterminate no...

Biological exposures to micro- and nano-scale exogenous metal particles generated as a consequence of in-service degradation of orthopaedic prosthetics can result in severe adverse tissues reactions. However, individual reactions are highly variable and are not easily predicted, due to in part a lack of understanding of the speciation of the metal-...

Iron is an essential cofactor for symbiotic nitrogen fixation. It is required by many of the enzymes facilitating the conversion of N2 into NH4+ by endosymbiotic bacteria living within root nodule cells, including signal transduction proteins, O2 homeostasis systems, and nitrogenase itself. Consequently, host plants have developed a transport netwo...

Objectives: The aim of this study was to determine in vivo if brain inflammation leads to increased gadolinium (Gd) retention in brain tissue after repeated applications of Gd-based contrast agents (GBCAs). Materials and methods: Experimental autoimmune encephalomyelitis (EAE) was induced in female SJL/J mice (n = 6). Experimental autoimmune enc...

Increasing evidence indicates the presence of engineered nanoparticles (ENPs) in sewage sludge derived from wastewater treatment. Land application of sewage sludge is, therefore, considered as an important pathway for ENP transfer to the environment. The aim of this work was to understand the effects of sewage sludge containing nano-TiO 2 on plants...

Seeds accumulate iron during embryo maturation stages of embryogenesis. Using Arabidopsis thaliana as model plant, it has been described that mature embryos accumulate iron within a specific cell layer, the endodermis. This distribution pattern was conserved in most of the analyzed members from Brassicales, with the exception of the basal Vasconcel...

The morphology of TiO 2 particles and their status within soil aggregates may provide insights on their origin.

The Cave of Swords was discovered in 1910 at Naica, Chihuahua, México. During the last century, human presence has changed the microclimate conditions inside this cave, raising the question of whether anthropogenic action resulted in the deterioration of its gypsum single crystals and in the deposition of impurities on their surfaces. The present w...

A multiscale description of (Bi0.5Na0.5)0.94Ba0.06TiO3 (BNBT6) ceramic is presented. High piezoelectric and electromechanical parameters (d33 = 167 pC/N, kt = 48.6%) were experimentally determined. The ceramic's crystal structure, after poling, was determined from synchrotron X-ray diffraction. The Rietveld analysis reveals a highly textured BNBT6...

Synchrotron radiation X-ray fluorescence microscopy is frequently used to investigate the spatial distribution of elements within a wide range of samples. Interrogation of heterogeneous samples that contain large concentration ranges has the potential to produce image artefacts due to the profile of the X-ray beam. The presence of these artefacts a...

Stenotrophomonas maltophilia is a microorganism that exhibits a wide range of applications. In this study, a Box-Behnken design was used to determine the optimum parameters for maximizing the cellulase production by S. maltophilia isolated from soil. The factors that were evaluated were the pH (3 to 10), carbon source (0.5 wt.% to 1.5 wt.% carboxym...

Cadmium (Cd) was shown to co-localise with calcium (Ca) in oxalate crystals in stems and leaves of Cd tolerant Gomphrena claussenii, but Cd binding remained unresolved. Using synchrotron radiation X-ray absorption near edge spectroscopy we demonstrate that in oxalate crystals of hydroponically grown G. claussenii the vast majority of Cd is bound to...

In this contribution we want to show how the intramineral proteins affect the crystal morphology of calcite crystals grown in vitro. Intramineral proteins from emu eggshells and two crocodiles’ species were isolated, purified by ultra-fast liquid chromatography (UFLC), and characterized by biochemical and biophysical methods. We could see that the...

Localization, Characterization and Local Biokinetics of Tattoo Pigment Particles in Human Skin and Lymph Nodes by Means of Synchrotron-based Micro- and NanoXRF - Volume 24 Supplement - Christian Seim, Ines Schreiver, Bernhard Hesse, Hiram Castillo-Michel, Julie Villanova, Peter Laux, Nadine Dreiack, Randolf Penning, Remi Tucoulou, Marine Cotte, And...

Iron as a trace element plays a role in regulating the homeostasis of the human body and therefore the concentration of iron in the body must be carefully monitored. Both a deficiency and overload of iron could have a serious effect on health. Iron in excess can be carcinogenic in different ways. As a catalyst of Fenton’s reaction it leads to the c...

Chronic psychological stress is an important public health issue which generates behavioral changes, anxiety, immunosuppression and oxidative damage. Piracetam is a cognitive enhancer, at cellular level it protects from oxidative stress. The aim of this study was to evaluate the effect of psychological stress and of piracetam on circulating mononuc...

Ovarian cancer is the seventh most common cancer among women across the world with very high mortality rates. Histology is considered the gold standard for tumour diagnosis. FTIR spectroscopy is relies on registering biochemical differences in the samples analysed, including biological specimens. Therefore, the Synchrotron radiation based-Fourier t...

The changes occurring during the depolymerization of lignocellulosic biomasses are not yet fully understood. Synchrotron micro‐Fourier Transform InfraRed (µ‐FTIR), Raman Spectroscopy (RS), X‐Ray Diffraction (XRD), and X‐Ray Fluorescence (XRF) were used for better characterization of Wheat Straw fibers during a continuous pretreatment process: Condi...

Amyloid plaques made of aggregated Aβ amyloid peptide are a pathological hallmark in brains affected by Alzheimer’s disease. Moreover, the amyloid peptide may play a major role in the onset and development of the disease in association to other factor such as oxidative stress. Although the molecular nature of the amyloid toxic species is still unkn...

The interactions of nanoparticles (NPs) with biochar (BC) and soil components may substantially influence NP availability and toxicity to biota. In the present study, earthworms (Eisenia fetida) were exposed for 28 d to a residential or agricultural soil amended with 0-2000 mg CeO2 NP/kg and with biochar (produced by the pyrolysis of pecan shells a...

Sulfidation is a key process for silver nanoparticles released from consumer products in the environment. This study focuses on the impact of a model soil microorganism, Bacillus subtilis, on the fate of pristine and already sulfidized Ag-NPs. The nanoparticles were incubated with the initial growth medium, isolated secretome and living bacteria, a...