The key role of biogenic arsenic sulfides in the removal of soluble arsenic and propagation of arsenic mineralizing communities.

Biogeochemical processes govern the transport and availability of arsenic in sediments. However, little is known about the transition from indigenous communities to cultivable consortia when exposed to high arsenic concentrations. Such cultivable communities could be exploited for arsenic bioremediation of waste streams and polluted sites. Thus, it is crucial to understand the dynamics and selective pressures that shape the communities during the development of customized bacterial consortia. First, from the arsenic partitioning of two sediments with high arsenic concentrations, we found that up to 55% of arsenic was bioavailable because it was associated with the soluble, carbonate, and ionically exchangeable fractions. Next, we prepared sediment enrichment cultures under arsenate- and sulfate-reducing conditions to precipitate arsenic sulfide biominerals and analyze the communities. The produced biominerals were used as the inoculum to develop bacterial consortia via successive transfers. Tracking of the 16S rRNA gene in the fresh sediments, sediment enrichments, biogenic minerals, and bacterial consortia revealed differences in the bacterial communities. Removing the sediment caused a substantial decrease in diversity and shifts toward the dominance of the Firmicutes phylum to the detriment of Proteobacteria. In agreement with the 16S rRNA gene results, the sequencing of the arrA gene confirmed the presence of phylotypes closely related to Desulfosporosinus sp. Y5 (100% similarity), highlighting the pivotal role of this genus in the removal of soluble arsenic. Here, we demonstrated for the first time that besides being important as arsenic sinks, the biogenic arsenic sulfide minerals are reservoirs of arsenic resistant/respiring bacteria and can be used to culture them.

Antimony toxicity upon microorganisms from aerobic and anaerobic environments.

Antimony (Sb) is a toxic and carcinogenic metalloid that can be present in contaminated water generated by mining operations and other industrial activities. The toxicity of Sb (III) and Sb (V) to aerobic microorganisms remains limited and unexplored for anaerobic microorganisms involved in hydrogen (H2) and methane (CH4) production. This study aimed to evaluate the toxicity of Sb (III) and Sb (V) upon aerobic and anaerobic microorganisms important in biological wastewater treatment systems. Sb (III) was more toxic than Sb (V) independently of the test and environment evaluated. Under aerobic conditions maintained in the Microtox assay, Sb (V) was not toxic to Allivibrio fischeri at concentrations as high as 500 mg/L, whereas Sb (III) caused just over 50% inhibition at concentration of 250 mg/L after 5 min of exposure. In the respirometry test, for the specific oxygen uptake rate, the concentrations of Sb (III) and Sb (V) displaying 50% inhibition were 0.09 and 56.2 mg/L, respectively. Under anaerobic conditions, exposure to Sb (III) and Sb (V) led to a decrease in microorganisms activity of fermentative and methanogenic processes. The results confirm that the microbial toxicity of Sb depends on its speciation and Sb (III) displays a significantly higher inhibitory potential than Sb (V) in both aerobic and anaerobic environments.

NanoAdventure: Development of a Text-Based Adventure Game in English, Spanish, and Chinese for Communicating about Nanotechnology and the Nanoscale.

Video games and immersive, narrative experiences are often called upon to help students understand difficult scientific concepts, such as sense of scale. However, the development of educational video games requires expertise and, frequently, a sizable budget. Here, we report on the use of an interactive text-style video game, NanoAdventure, to communicate about sense of scale and nanotechnology to the public. NanoAdventure was developed on an open-source, free-to-use platform with simple coding and enhanced with free or low-cost assets. NanoAdventure was launched in three languages (English, Spanish, Chinese) and compared to textbook-style and blog-style control texts in a randomized study. Participants answered questions on their knowledge of nanotechnology and their attitudes toward nanotechnology before and after reading one randomly assigned text (textbook, blog, or NanoAdventure game). Our results demonstrate that interactive fiction is effective in communicating about sense of scale and nanotechnology as well as the relevance of nanotechnology to a general public. NanoAdventure was found to be the most "fun" and easy to read of all text styles by participants in a randomized trial. Here, we make the case for interactive "Choose Your Own Adventure" style games as another effective tool among educational game models for chemistry and science communication.

Designing bacterial consortia for the complete biodegradation of insensitive munitions compounds in waste streams.

Insensitive munitions compounds (IMCs), such as 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), are replacing conventional explosives in munitions formulations. Manufacture and use of IMCs generate waste streams in manufacturing plants and load/assemble/pack facilities. There is a lack of practical experience in executing biodegradation strategies to treat IMCs waste streams. This study establishes a proof-of-concept that bacterial consortia can be designed to mineralize IMCs and co-occurring nitroaromatics in waste streams. First, DNAN, 4-nitroanisole (4-NA), and 4-chloronitrobenzene (4-CNB) in a synthetic DNAN-manufacturing waste stream were biodegraded using an aerobic fluidized-bed reactor (FBR) inoculated with Nocardioides sp. JS 1661 (DNAN degrader), Rhodococcus sp. JS 3073 (4-NA degrader), and Comamonadaceae sp. LW1 (4-CNB degrader). No biodegradation was detected when the FBR was operated under anoxic conditions. Second, DNAN and NTO were biodegraded in a synthetic load/assemble/pack waste stream during a sequential treatment comprising: (i) aerobic DNAN biodegradation in the FBR; (ii) anaerobic NTO biotransformation to 3-amino-1,2,4-triazol-5-one (ATO) by an NTO-respiring enrichment; and (iii) aerobic ATO mineralization by an ATO-oxidizing enrichment. Complete biodegradation relied on switching redox conditions. The results provide the basis for designing consortia to treat mixtures of IMCs and related waste products by incorporating microbes with the required catabolic capabilities.

Quinone Moieties Link the Microbial Respiration of Natural Organic Matter to the Chemical Reduction of Diverse Nitroaromatic Compounds.

Insensitive munitions compounds (IMCs) are emerging nitroaromatic contaminants developed by the military as safer-to-handle alternatives to conventional explosives. Biotransformation of nitroaromatics via microbial respiration has only been reported for a limited number of substrates. Important soil microorganisms can respire natural organic matter (NOM) by reducing its quinone moieties to hydroquinones. Thus, we investigated the NOM respiration combined with the abiotic reduction of nitroaromatics by the hydroquinones formed. First, we established nitroaromatic concentration ranges that were nontoxic to the quinone respiration. Then, an enrichment culture dominated by Geobacter anodireducens could indirectly reduce a broad array of nitroaromatics by first respiring NOM components or the NOM surrogate anthraquinone-2,6-disulfonate (AQDS). Without quinones, no nitroaromatic tested was reduced except for the IMC 3-nitro-1,2,4-triazol-5-one (NTO). Thus, the quinone respiration expanded the spectrum of nitroaromatics susceptible to transformation. The system functioned with very low quinone concentrations because NOM was recycled by the nitroaromatic reduction. A metatranscriptomic analysis demonstrated that the microorganisms obtained energy from quinone or NTO reduction since respiratory genes were upregulated when AQDS or NTO was the electron acceptor. The results indicated microbial NOM respiration sustained by the nitroaromatic-dependent cycling of quinones. This process can be applied as a nitroaromatic remediation strategy, provided that a quinone pool is available for microorganisms.

Bacteria Make a Living Breathing the Nitroheterocyclic Insensitive Munitions Compound 3-Nitro-1,2,4-triazol-5-one (NTO).

The nitroheterocyclic 3-nitro-1,2,4-triazol-5-one (NTO) is an ingredient of insensitive explosives increasingly used by the military, becoming an emergent environmental pollutant. Cometabolic biotransformation of NTO occurs in mixed microbial cultures in soils and sludges with excess electron-donating substrates. Herein, we present the unusual energy-yielding metabolic process of NTO respiration, in which the NTO reduction to 3-amino-1,2,4-triazol-5-one (ATO) is linked to the anoxic acetate oxidation to CO2 by a culture enriched from municipal anaerobic digester sludge. Cell growth was observed simultaneously with NTO reduction, whereas the culture was unable to grow in the presence of acetate only. Extremely low concentrations (0.06 mg L-1) of the uncoupler carbonyl cyanide m-chlorophenyl hydrazone inhibited NTO reduction, indicating that the process was linked to respiration. The ultimate evidence of NTO respiration was adenosine triphosphate production due to simultaneous exposure to NTO and acetate. Metagenome sequencing revealed that the main microorganisms (and relative abundances) were Geobacter anodireducens (89.3%) and Thauera sp. (5.5%). This study is the first description of a nitroheterocyclic compound being reduced by anaerobic respiration, shedding light on creative microbial processes that enable bacteria to make a living reducing NTO.

Prevalence of fibromyalgia and associated factors in Spain.

OBJECTIVES: The prevalence of fibromyalgia (FM) differs depending on the population studied. The main objective of the EPISER2016 study was to estimate the prevalence of FM in adults in Spain. The secondary objective was to evaluate the association with sociodemographic and anthropometric characteristics and smoking. METHODS: This is a population-based cross-sectional multicentre study. The random selection was based on multistage stratified cluster sampling. The final sample comprised 4916 persons aged ≥20 years. Participants were contacted by telephone for completion of a screening survey. Investigating rheumatologists evaluated positive results (review of medical records and/or telephone interview, with medical visit if needed) to confirm the diagnosis. Prevalence and 95% confidence interval were calculated, taking into account the sample design. Weighing was applied based on age, sex, and geographic origin. Predictive models were constructed to analyse which sociodemographic, anthropometric and lifestyle variables in the call centre questionnaire were associated with the presence of FM. RESULTS: 602 subjects (12.25%) had a positive screening result for FM, of which 24 were missing (3.99%). A total of 141 cases of FM were recorded. The estimated prevalence was 2.45% (95% CI, 2.06-2.90). Female sex was the variable most associated with FM, with an odds ratio (OR) of 10.156 (95% CI, 5.068-20.352). Peak prevalence was at 60-69 years (p=0.009, OR=6.962). FM was 68% more frequent in obese individuals (OR, 1.689; 95% CI, 1.036-2.755). CONCLUSIONS: The prevalence of FM in adults in Spain barely changed between 2000 and 2016 and it is similar to that observed in Europe as a whole.

Effects of graphene oxide and reduced graphene oxide on acetoclastic, hydrogenotrophic and methylotrophic methanogenesis.

This study describes the effects of graphene oxide (GO) and reduced graphene oxide (rGO) on the acetoclastic, hydrogenotrophic and methylotrophic pathways of methanogenesis by an anaerobic consortium. The results showed that GO negatively affected the hydrogenotrophic and acetoclastic pathways at a concentration of 300 mg/L, causing a decrease of ~ 38% on the maximum specific methanogenic activity (MMA) with respect to the controls lacking GO. However, the presence of rGO (300 mg/L) promoted an improvement of the MMA (> 45%) achieved with all substrates, except for the hydrogenotrophic pathway, which was relatively insensitive to rGO. The presence of either rGO or GO enhanced the methylotrophic pathway and resulted in an increase of the MMA of up to 55%. X-ray photoelectron spectroscopy (XPS) analysis revealed that GO underwent microbial reduction during the incubation period. Electrons derived from substrates oxidation were deviated from methanogenesis towards the reduction of GO, which may explain the MMA decreased observed in the presence of GO. Furthermore, XPS evidence indicated that the extent of GO reduction depended on the metabolic pathway triggered by a given substrate.

Cytotoxicity Assessment of Gallium- and Indium-Based Nanoparticles Toward Human Bronchial Epithelial Cells Using an Impedance-Based Real-Time Cell Analyzer.

The semiconductor manufacturing sector plans to introduce III/V film structures (eg, gallium arsenide (GaAs), indium arsenide (InAs) onto silicon wafers due to their high electron mobility and low power consumption. Aqueous solutions generated during chemical and mechanical planarization of silicon wafers can contain a mixture of metal oxide nanoparticles (NPs) and soluble indium, gallium, and arsenic. In this work, the cytotoxicity induced by Ga- and In-based NPs (GaAs, InAs, Ga2O3, In2O3) and soluble III-V salts on human bronchial epithelial cells (16HBE14o-) was evaluated using a cell impedance real-time cell analysis (RTCA) system. The RTCA system provided inhibition data at different concentrations for multiple time points, for example, GaAs (25 mg/L) caused 60% inhibition after 8 hours of exposure and 100% growth inhibition after 24 hours. Direct testing of As(III) and As(V) demonstrated significant cytotoxicity with 50% growth inhibition concentrations after 16-hour exposure (IC50) of 2.4 and 4.5 mg/L, respectively. Cell signaling with rapid rise and decrease in signal was unique to arsenic cytotoxicity, a precursor of strong cytotoxicity over the longer term. In contrast with arsenic, soluble gallium(III) and indium(III) were less toxic. Whereas the oxide NPs caused low cytotoxicity, the arsenide compounds were highly inhibitory (IC50 of GaAs and InAs = 6.2 and 68 mg/L, respectively). Dissolution experiments over 7 days revealed that arsenic was fully leached from GaAs NPs, whereas only 10% of the arsenic was leached out of InAs NPs. These results indicate that the cytotoxicity of GaAs and InAs NPs is largely due to the dissolution of toxic arsenic species.

Microbial toxicity of gallium- and indium-based oxide and arsenide nanoparticles.

III-V semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs) are increasingly used in the fabrication of electronic devices. There is a growing concern about the potential release of these materials into the environment leading to effects on public and environmental health. The waste effluents from the chemical mechanical planarization process could impact microorganisms in biological wastewater treatment systems. Currently, there is only limited information about the inhibition of gallium- and indium-based nanoparticles (NPs) on microorganisms. This study evaluated the acute toxicity of GaAs, InAs, gallium oxide (Ga2O3), and indium oxide (In2O3) particulates using two microbial inhibition assays targeting methanogenic archaea and the marine bacterium, Aliivibrio fischeri. GaAs and InAs NPs were acutely toxic towards these microorganisms; Ga2O3 and In2O3 NPs were not. The toxic effect was mainly due to the release of soluble arsenic species and it increased with decreasing particle size and with increasing time due to the progressive corrosion of the NPs in the aqueous bioassay medium. Collectively, the results indicate that the toxicity exerted by the arsenide NPs under environmental conditions will vary depending on intrinsic properties of the material such as particle size as well as on the dissolution time and aqueous chemistry.

LC-ICP-OES method for antimony speciation analysis in liquid samples.

A method for the analysis of different species of antimony (Sb) that couples liquid chromatography with an inductively coupled plasma-optical emission spectrometry (LC-ICP-OES) system is presented. The method is simple and reliable to separate and quantify directly and simultaneously Sb(III) and Sb(V) in aqueous samples. The calibration curves showed high linearity at the three wavelengths tested. The limits of detection ranged from 24.9 to 32.3 µg/L for Sb(III) and from 36.2 to 46.0 µg/L for Sb(V), at the three wavelengths evaluated. The limit of detection for this method varied depending on the wavelength used. The lowest limit of quantification for Sb(V) (49.9 µg/L) and Sb(III) (80.7 µg/L) was obtained at a wavelength of 217.582 nm. The method sensitivity for Sb(V) was higher compared to Sb(III) at all the wavelengths considered. Samples containing different concentrations of Sb(III) and Sb(V) in three different matrices, i.e., water, basal culture medium, and anaerobic sludge plus basal medium, were analyzed. The coefficients of variation were low and ranged from 0.1 to 5.0 depending on the sample matrix. Recoveries of Sb(III) and Sb(V) were higher than 90% independently of the matrix analyzed and the wavelength used in the analysis.

Rapid biotransformation of the insensitive munitions compound, 3-nitro-1,2,4-triazol-5-one (NTO), by wastewater sludge.

As the use of the new insensitive munitions compound 3-nitro-1,2,4-triazol-5-one (NTO) increases, wastewaters, runoff and groundwater containing NTO will be generated. Little is known about the fate of NTO during biological wastewater treatment. The objective of this study was to explore the ability of wastewater sludges to promote the biotransformation of NTO. Three different sludges, i.e., anaerobic granular sludge, anaerobic digested sludge, and return activated sludge, were used to study the biotransformation of NTO under anaerobic conditions. Three different electron donor amendments were compared- hydrogen, ethanol, and acetate. Mixed microbial communities in each of the three sludge sources were effective in the reductive biotransformation of NTO. 3-amino-1,2,4-triazol-5-one (ATO) was observed as the major product of NTO biotransformation. The highest maximum specific rate of NTO reduction, about 120 mg NTO/g volatile suspended solids/d, was observed in anaerobic granular sludge with hydrogen or ethanol supplied as electron donors. NTO biotransformation to ATO by anaerobic digested sludge was also studied under denitrifying conditions. In this case, reduction of NTO started only after complete denitrification of added nitrate. An important implication of this paper is that sludge from wastewater treatment plants can rapidly and readily reduce NTO to ATO.

Adaptation of granular sludge microbial communities to nitrate, sulfide, and/or p-cresol removal.

Effluents from petroleum refineries contain a toxic mixture of sulfide, nitrogen, and phenolic compounds that require adequate treatment for their removal. Biological denitrification processes are a cost-effective option for the treatment of these effluents, but the knowledge on the microbial interactions in simultaneous sulfide and phenol oxidation in denitrifying reactors is still very limited. In this work, microbial community structure and macrostructure of granular biomass were studied in three denitrifying reactors treating a mixture of inorganic (sulfide) and organic (p-cresol) electron donors for their simultaneous removal. The differences in the available substrates resulted in different community assemblies that supported high removal efficiencies, indicating the community adaptation capacity to the fluctuating compositions of industrial effluents. The three reactors were dominated by nitrate reducing and denitrifying bacteria where Thiobacillus spp. were the prevalent denitrifying organisms. The toxicity and lack of adequate substrates caused the endogenous decay of the biomass, leading to release of organic matter that maintained a diverse although not very abundant group of heterotrophs. The endogenous digestion of the granules caused the degradation of its macrostructure, which should be considered to further develop the denitrification process in sulfur-based granular reactors for treatment of industrial wastewater with toxic compounds.

Microbial Enrichment Culture Responsible for the Complete Oxidative Biodegradation of 3-Amino-1,2,4-triazol-5-one (ATO), the Reduced Daughter Product of the Insensitive Munitions Compound 3-Nitro-1,2,4-triazol-5-one (NTO).

3-Nitro-1,2,4-triazol-5-one (NTO) is one of the main ingredients of many insensitive munitions, which are being used as replacements for conventional explosives. As its use becomes widespread, more research is needed to assess its environmental fate. Previous studies have shown that NTO is biologically reduced to 3-amino-1,2,4-triazol-5-one (ATO). However, the final degradation products of ATO are still unknown. We have studied the aerobic degradation of ATO by enrichment cultures derived from the soil. After multiple transfers, ATO degradation was monitored in closed bottles through measurements of inorganic carbon and nitrogen species. The results indicate that the members of the enrichment culture utilize ATO as the sole source of carbon and nitrogen. As ATO was mineralized to CO2, N2, and NH4+, microbial growth was observed in the culture. Co-substrates addition did not increase the ATO degradation rate. Quantitative polymerase chain reaction analysis revealed that the organisms that enriched using ATO as carbon and nitrogen source were Terrimonas spp., Ramlibacter-related spp., Mesorhizobium spp., Hydrogenophaga spp., Ralstonia spp., Pseudomonas spp., Ectothiorhodospiraceae, and Sphingopyxis. This is the first study to report the complete mineralization of ATO by soil microorganisms, expanding our understanding of natural attenuation and bioremediation of the explosive NTO.

Platinum(II) reduction to platinum nanoparticles in anaerobic sludge.

BACKGROUND: To help mitigate future problems in the supply of platinum group metals (PGM) due to their scarcity and high demand, new recovery processes must be developed. Microbial processes are a great alternative for the recovery of PGM from waste since they are clean and environmentally friendly techniques. This research studied the microbial reduction of Pt(II) using an anaerobic granular sludge under different physiological conditions. RESULTS: The anaerobic granular sludge was able to reduce Pt(II) to Pt(0) nanoparticles that were deposited intracellularly as well as extracellularly as confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. Hydrogen (H2) and formate supported the chemical reduction of Pt(II) while ethanol supported the biologically catalyzed reduction of Pt(II). Increasing initial concentrations of Pt(II), ethanol or biomass were each shown to increase the Pt(II) reduction rates. CONCLUSIONS: This study reported for the first time the reduction of Pt(II) using anaerobic granular sludge and provided insights that could help develop biorecovery techniques to alleviate future problems in the supply of PGMs.

The role of contextual signal TGF-ß1 inducer of epithelial mesenchymal transition in metastatic lung adenocarcinoma patients with brain metastases: an update on its pathological significance and therapeutic potential.

Lung adenocarcinoma (LA) is the most common cause of cancer-related death worldwide. Despite the advances over last decade in new targeted therapies, cancer genetics, diagnostics, staging, and surgical techniques as well as new chemotherapy and radiotherapy protocols, the death rate from LA remains high. The tumour microenvironment is composed of several cytokines, one of which is transforming growth factor ß1 (TGF-ß1), which modulates and mediates the expression of epithelial-mesenchymal transition (EMT), correlated with invasive growth in LAs, and exhibits its pleiotropic effects through binding to transmembrane receptors TßR-1 (also termed activin receptor-like kinases - ALKs) and TßR-2. Accordingly, there is an urgent need to elucidate the molecular mechanisms associated with the tumoural spreading process and therapeutic resistance of this serious pathology. In this review, we briefly discuss the current role of contextual signal TGF-ß1 inducer of epithelial mesenchymal transition in metastatic lung adenocarcinoma patients with brain metastases, and give an overview of our current mechanistic understanding of the TGF-ß1-related pathways in brain metastases progression, TGF-ß1 pathway inhibitors that could be used for clinical treatment, and examination of models used to study these processes. Finally, we summarise the current progress in the therapeutic approaches targeting TGF-ß1.

Cornalean affinities, phylogenetic significance, and biogeographic implications of Operculifructus infructescences from the Late Cretaceous (Campanian) of Mexico.

IN ENGLISH: Premise of the Study Cretaceous Cornales provide a crucial record of the early history of asterids. Most lineages of the order are well represented in the fossil record, but South African families of Curtisiaceae and Grubbiaceae remain poorly understood. Seventy-three specimens of a fossil infructescence belonging to the genus Operculifructus Estrada-Ruiz & Cevallos-Ferriz emend. Hayes & Smith from the Late Cretaceous (Campanian) El Gallo Formation, Baja California, Mexico bear previously undescribed characters that suggest a relationship to Grubbiaceae. Methods Microstructures of the fossils were examined through light microscopy and x-ray microcomputed tomography (microCT) scanning. Modern Grubbia tomentosa (Thunb.) Harms fruits were scanned for comparison to the fossil material. Phylogenetic analyses using the 77 fruit characters of Atkinson () were performed to test relationships of the fossil to major lineages of the order. Several analyses applied topological constraints to the extant taxa, based on various genetically supported hypotheses of relationship within Cornales. Key Results Novel structures of Operculifructus newly observed here include (1) anatropous ovules, (2) drupaceous fruits, (3) an epigynous disc, (4) and a stylar canal in the center of the disc aligned with the micropylar protrusion of the seed. Phylogenetic analysis consistently resolves Operculifructus as sister to Grubbiaceae. Conclusions Operculifructus provides direct evidence for the occurrence of Grubbiaceae in the Late Cretaceous, much older than previous Eocene evidence. The phylogeny of Atkinson () indicates that the new phylogenetic position recovered for Operculifructus also establishes the presence of the most basal drupaceous cornalean fruits in North America by the Campanian. RESUMEN EN ESPAÑOL Hipótesis de la Investigación Cornales cretácicos representan un registro esencial en la historia de los astéridos. Casi todos los linajes del orden están bien representados en el registro fósil, pero las familias africanas sureñas Curtisiaceae y Grubbiaceae permanecen pobremente entendidas. Setenta y tres ejemplares de una infrutescencia fósil perteneciente al género Operculifructus Estrada-Ruiz & Cevallos-Ferriz emend. Hayes & Smith de la formación campaniana (Cretácico Tardío) El Gallo, Baja California, México, poseen caracteres no descritos previamente y sugieren una relación con Grubbiaceae. Metodología Microestructuras de los fósiles fueron examinadas con microscopio de luz y microtomografía computarizada (micro-CT) de rayos X. Frutos actuales de Grubbia tomentosa (Thunb.) Harms fueron escaneados para su comparación con el material fósil. Se realizaron análisis filogenéticos usando los 77 caracteres de frutos de Atkinson () para probar las relaciones de los fósiles con los linajes principales del orden. En algunos análisis se aplicaron restricciones topológicas a los taxa actuales basándose en varias hipótesis, soportadas genéticamente, de las relaciones dentro de Cornales. Resultados Centrales (Cruciales) Las estructuras novedosas de Operculifructus, recientemente observadas aquí, incluyen (1) óvulos anátropos; (2) frutos drupáceos; (3) disco epígino; y (4) un canal estilar en el centro del disco alineado con la protuberancia micropilar de la semilla. Los análisis filogenéticos consistentemente dan como resultado que Operculifructus es hermano de Grubbiaceae. Conclusiones Operculifructus proporciona evidencia directa de la presencia de Grubbiaceae en el Cretácico Tardío, mucho antes que la previa evidencia en el Eoceno. La filogenia de Atkinson () indica que la nueva posición filogenética recuperada para Operculifructus también resalta la presencia de frutos drupáceos cornaleanos más basales en Norteamérica durante el Campaniano.

Cerium dioxide (CeO2) nanoparticles decrease arsenite (As(III)) cytotoxicity to 16HBE14o- human bronchial epithelial cells.

The production and application of engineered nanoparticles (NPs) are increasing in demand with the rapid development of nanotechnology. However, there are concerns that some of these novel materials could lead to emerging environmental and health problems. Some NPs are able to facilitate the transport of contaminants into cells/organisms via a "Trojan Horse" effect which enhances the toxicity of the adsorbed materials. In this work, we evaluated the toxicity of arsenite (As(III)) adsorbed onto cerium dioxide (CeO2) NPs to human bronchial epithelial cells (16HBE14o-) using the xCELLigence real time cell analyzing system (RTCA). Application of 0.5 mg/L As(III) resulted in 81.3% reduction of cell index (CI, an RTCA measure of cell toxicity) over 48 h when compared to control cells exposed to medium lacking As(III). However, when the cells were exposed to 0.5 mg/L As(III) in the presence of CeO2 NPs (250 mg/L), the CI was only reduced by 12.9% compared to the control. The CeO2 NPs had a high capacity for As(III) adsorption (20.2 mg/g CeO2) in the bioassay medium, effectively reducing dissolved As(III) in the aqueous solution and resulting in reduced toxicity. Transmission electron microscopy was used to study the transport of CeO2 NPs into 16HBE14o- cells. NP uptake via engulfment was observed and the internalized NPs accumulated in vesicles. The results demonstrate that dissolved As(III) in the aqueous solution was the decisive factor controlling As(III) toxicity of 16HBE14o- cells, and that CeO2 NPs effectively reduced available As(III) through adsorption. These data emphasize the evaluation of mixtures when assaying toxicity.

Reduction of platinum (IV) ions to elemental platinum nanoparticles by anaerobic sludge.

BACKGROUND: The future supply of platinum group metals (PGM) is at risk because of their scarcity combined with a high demand. Thus recovery of platinum (Pt) from waste is an option worthy of study to help alleviate future shortages. This research explored the microbial reduction of platinum (Pt). The ability of anaerobic granular sludge to reduce Pt(IV) ions under different physiological conditions was studied. RESULTS: X-Ray diffraction (XRD) and transmission electron microscope (TEM) analyses demonstrated the capacity of the microbial mixed culture to reduce Pt(IV) to Pt(0) nanoparticles, which were deposited on the cell-surface and in the periplasmic space. Ethanol supported the biologically catalyzed Pt(IV) reduction, meanwhile other electron donors; hydrogen (H2) and formate, promoted the chemical reduction of Pt(IV) with some additional biological stimulation in the case of H2. A hypothesis is proposed in which H2 formed from the acetogenesis of ethanol is implicated in subsequent abiotic reduction of Pt(IV) indicating an integrated bio-chemical process. Endogenous controls also resulted in slow Pt(IV) removal from aqueous solution. Selected redox mediators, exemplified by riboflavin, enhanced the Pt(IV) reduction rate. CONCLUSION: This study reported for the first time the ability of an anaerobic granular sludge to reduce Pt(IV) to elemental Pt(0) nanoparticles.

Giant cranionasal epithelioid haemangioendothelioma with invasive growth pattern mimicking a skull base chondrosarcoma.

Epithelioid haemangioendothelioma (EHE) is a rare low-grade vascular neoplasm that is composed of mostly epithelioid cells. EHE may arise as a solitary tumour or in the form of multiple body lesions, and commonly occurs in soft tissues, liver, pleura, lung, peritoneum, lymph nodes, breast, and many other sites. EHE in the cranionasal region is extremely rare. There are very few reports of cases of skull-base EHE. We discuss an extremely rare presentation of an aggressive EHE that originated from the sellar region. Based on literature review, our patient is the first reported case of a giant solitary EHE with prepontine cistern invasion and abducens nerve encroachment mimicking a chondrosarcoma. We treated this rare tumour by near subtotal surgical excision with subsequent radiotherapy, considering that complete tumour resection with free margins in both cavernous sinus and clival region avoiding neural and vascular structure encroachment becomes technically difficult.