Graphene oxide toxicological effects on daphnia and hydra.

The increased use of nanomaterials products requires robust strategies to identify risks when they are released into the environment. Graphene and its derivatives are promising candidates for biomedical applications and as potential advanced water purification agents. However, little is known about their ecotoxicological risks. Aquatic toxicity tests are performed with different aquatic organisms as daphnia and hydra in order to evaluate the risks resulting from the presence of graphene oxide (GO) in the environment. The following GO concentrations were tested: 0, 1, 10 and 100 mg.L-1. Acute toxicity to D. magna was evaluated in a period of 48 hours when was recorded the number of moving subjects in order to determine the CE5024h and CE5048h (n = 24 / group). The percentage of daphnia presenting mobility after 48 hours of exposure was greater than 60% in all groups. There was a concentration effect of graphene oxide (p = 0.02) and mobility was 20% lower in group exposed to 100 mg.L-1 than the control group. To evaluate the occurrence of the effect of sublethal concentrations for 96 h, it was evaluate neonate D. similis growth rate through exposure to the same conditions used for acute toxicity testing (n = 10 / group). The bodies were photographed at the start of the test and every 24 hours. Also, there was studied the effect of the organisms mobility during 96 hours calculating the median survival time of the population, defined as the average time between the start of exposure and the immobility of organisms. There was a sharp decline when the organisms were subjected to 100 mg. L-1 GO. The Hydra attenuata test was performed for 96h. The organisms were observed every 24 hours for the presence of changes ranging from tentacles with bulbs (low toxicity) till shortening of the tentacles (severe toxicity), tulip aspect and disintegration (lethal). A mean score for each concentration was calculated. No mortality was observed in any concentration tested. However, it was observed some morphological alterations after 72h of 100.0 mg.L-1 exposure as clubbed and shortened tentacles and body slightly contracted. Exposures of the test organisms indicate that GO do not present a lethal risk or adversely affect them at concentrations lower to 10.0 mg. L-1. Even though the results apparently demonstrate that GO currently do not pose a serious risk, it may exert some damage in aquatic organisms tested at higher doses

Zebrafish exposure to graphene oxide is related to behavior changes.

Graphene oxide (GO) has been explored to application in areas such as pharmaceutical and environmental sciences. However, GO safety is still unclear. Beyond that, environmental factors, as the presence of humic substances in aquatic environment, can affect nanomaterials behavior and its toxicological effects. The motor development of zebrafish embryo has been strongly characterized and established to neurotoxicity studies. A previous study of our group revealed that the exposure of zebrafish embryos to GO is related to a reduction in total body length and in acetylcholinesterase activity. Morphological and biochemical changes can be related to behavior abnormalities and affect organism?s survival, leading to serious environmental consequences. Thus, the aim of this study was to investigate the implications of GO exposure in zebrafish behavior under environmental conditions. Zebrafish embryos (n=48/group) were exposed to GO (100 mg/L) in the presence or absence of humic acid (HA, 20 mg/L) during 5 days. Larvae were not feed during the experiment and were exposed under a 14/10 h light/dark cycle, 26 ± 1oC. Twelve larvae per group were individually allocated in a 96 well-plate containing clean water and acclimated during 30 min. The following behavior?s biomarkers were monitored during 30 min through DanioVision video-tracking system: total time in movement, distance moved and swimming velocity. At the end of the experiment, larvae were fixed with PFA 4% and its total length and yolk sac were measured through a stereomicroscope. The mortality in all groups was below 10% and no malformation was observed. The statistical analysis (Two-way ANOVA followed by Bonferroni test) showed that, independently of HA presence, larvae exposed to GO dispended more time in movement, swam a greater distance, and showed higher swimming velocity than controls. The larvae exposed to GO, with or without HA, were about 3.8% shorter than control. There was no difference among groups related to yolk sac. The effect can be related to GO adsorption to larvae body that can act as tactile stimuli. Our previous study supports the hypothesis that GO can cause impairment in neuromuscular development. Further experiments are being performed to clarify these observations

Exploring the mechanisms of graphene oxide toxicity to zebrafish embryo.

Many applications of graphene oxide (GO) are still in the research phase, but its promising uses have raised concerns about their risks to human health and the environment. Environmental factors, as the presence of humic substances in aquatic environment, can affect nanomaterials behavior and its toxicological effects. A previous study of our group revealed that the exposure of zebrafish embryos to GO is related to a reduction in total body length and in acetylcholinesterase activity. Thus, the aim of this study was to investigate the implications of GO exposure in muscular development and acetylcholinesterase expression. Zebrafish embryos (n=48/group) were exposed to GO (100 mg/L) in the presence or absence of humic acid (HA, 20 mg/L) during 5 days. Larvae were not feed during the experiment and were exposed under a 14/10 h light/dark cycle, 26 ± 1oC. The mortality in all groups was below 10% and no malformation was observed. At the end of the experiment, alive larvae were fixed with PFA 4% to evaluate its muscular morphology (confocal microscopy, SHG technique) or frozen in liquid nitrogen to perform RT-PCR analysis (AchE expression). Measurements of sarcomere and somite length were performed. No change in muscular tissue was observed, neither differences in AchE expression among groups were detected. So, further experiments have to be performed to clarify the mechanisms of graphene toxicity. FAPESP grants 2014/01995-9, 2014/12891-0, 2014/15640-8

Importância da padronização do meio de exposição nas avaliações nanoecotoxicológicas.

As propriedades dos nanomateriais (NMs) dependem, dentre outras, da composição iônica do meio de exposição. Porém, a descrição do mesmo é negligenciada em diversas publicações na área. Apesar de existirem protocolos padronizados para estudos ecotoxicológicos com embriões de Danio rerio, o meio de exposição pode variar. O objetivo deste trabalho foi avaliar a influência da composição do meio de exposição na toxicidade de NMs. Estudou-se o carvão ativo nanoestruturado - sem (ACBP) e com nanopartículas de prata (ACBP-AgNPs) - sintetizado no LNNano. Esse novo material alia a capacidade de adsorção do carvão com a atividade antimicrobiana da prata, podendo ser utilizado na remediação ambiental. Embriões de D. rerio foram expostos aos NMs em concentrações de 1 a 100 mg/L, em dois diferentes meios de exposição: M1 (0,3 mS/cm, pH 7,5) e M2 (3 mS/cm, pH 7,5). A exposição em M2 apresentou maior toxicidade [CL50-96h = 25,83 (22,2-30,5) mg/L] do que em M1 [ CL50-96h de 90,09 (73,40-113,5) mg/L]. A toxicidade observada está relacionada às AgNPs, visto que a exposição a ACBP não apresentou toxicidade. A maior concentração de íons cloreto (17,9.10-4 mol/L) presente em M2 com relação a M1 (5.10-5 mol/L) pode estar relacionada à toxicidade observada. A literatura relata haver dissolução parcial das AgNPs na presença de cloretos, com formação de cloreto de prata. Nossos resultados evidenciam a necessidade de padronização dos meios de exposição em estudos nanotoxicológicos

Developing an infrastructure for secure patient summary exchange in the EU context: Lessons learned from the KONFIDO project

Background: The increase of healthcare digitalization comes along with potential information security risks. Thus, the EU H2020 KONFIDO project aimed to provide a toolkit supporting secure cross-border health data exchange. Methods: KONFIDO focused on the so-called “User Goals”, while also identifying barriers and facilitators regarding eHealth acceptance. Key user scenarios were elaborated both in terms of threat analysis and legal challenges. Moreover, KONFIDO developed a toolkit aiming to enhance the security of OpenNCP, the reference implementation framework. Results: The main project outcomes are highlighted and the “Lessons Learned,” the technical challenges and the EU context are detailed. Conclusions: The main “Lessons Learned” are summarized and a set of recommendations is provided, presenting the position of the KONFIDO consortium toward a robust EU-wide health data exchange infrastructure. To this end, the lack of infrastructure and technical capacity is highlighted, legal and policy challenges are identified and the need to focus on usability and semantic interoperability is emphasized. Regarding technical issues, an emphasis on transparent and standards-based development processes is recommended, especially for landmark software projects. Finally, promoting mentality change and knowledge dissemination is also identified as key step toward the development of secure cross-border health data exchange services

Toxicologia do óxido de grafeno: avaliação in vitro da influência da presença de debris oxidativos.

A presença de debris oxidativos, resíduos carbonáceos originados do processo de síntese do óxido de grafeno (OG), é um importante fator que pode influenciar suas propriedades, comportamento e efeitos toxicológicos. O objetivo deste estudo foi avaliar as propriedades e efeitos da suspensão de OG com e sem debris oxidativos sobre a atividade de enzimas envolvidas em diversos processos metabólicos, possíveis alvos de ação tóxica. As suspensões de OG com e sem debris (p-OG) foram caracterizadas através das técnicas de centrifugação, espectrofotometria e espalhamento dinâmico de luz (DLS). Homogenatos de larvas de Danio rerio com 96 horas pós-fertilização foram incubados com suspensões de OG e p-OG (30 mg/L, 20 min, 30o?C), para a avaliação da atividade específica de glutationa S-transferase (GST) e de fosfatase ácida (FA). O tamanho hidrodinâmico obtido por DLS foi levemente maior para o p-OG (358,16 ± 5,90 nm) do que para o OG (284,73 ± 17,29 nm). A remoção de debris reduziu a estabilidade do OG em suspensão e propiciou a precipitação mais rápida das partículas por centrifugação. Os testes in vitro mostraram que não houve alteração na atividade específica de GST, mas que ocorreu inibição da atividade de FA de 20 e 9% em relação ao controle pelo OG e p-OG respectivamente. Novos estudos serão conduzidos para verificação do envolvimento de um efeito direto sobre a enzima ou de um efeito quelante de cofatores e metais essenciais à estrutura e atividade catalítica

Trocas gasosas em mudas de café arábica submetidas ao déficit hídrico e deficiência de nitrogênio.

Nas principais áreas brasileiras de cultivo de café arabica longos períodos sem chuvas são frequentemente observados. A seca é considerada como o principal fator limitante para o cultivo de café nessas áreas. As condições de seca afetam o crescimento e produtividade da cultura, em parte, através de reduções na taxa de assimilação líquida de carbono (A), seja por um efeito direto da desidratação sobre o aparato fotossintético ou em decorrência do efeito indireto do fechamento dos estômatos. Assim, objetivou-se com esta pesquisa estudar o impacto da nutrição nitrogenada e do déficit hídrico sobre as trocas gasosas em mudas de café arábica. Para avaliar as trocas gasosas em condições de déficit hídrico e de nitrogênio cinco cultivares de café arábica foram submetidas aos seguintes tratamentos: N-suficiente (+N, 5,0 mmol L-1 N-NO3-) sem déficit hídrico, N-suficiente (+N, 5,0 mmol L-1 N-NO3-) com déficit hídrico (-1,5 MPa) e N-deficiente (-N, 0,0 mmol L-1 N-NO3-) sem déficit hídrico, em solução nutritiva. O experimento foi montado em câmara de crescimento com temperatura controlada (23-24 oC), luminosidade de 200 ?mol m-² s-¹e unidade relativa entre 56-58 %, tendo as plantas sido submetidas ao fotoperíodo de 12h/12h (luz/escuro). O período experimental foi de 96 h. O experimento foi montado em esquema fatorial 5x9, composto de 5 cultivares de café (Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 44, Acauã, Catucaí Amarelo 2SL e Mundo Novo IAC 379-19) e três tratamentos (descritos acima) no delineamento em blocos casualizados com três repetições onde cada parcela era constituída por duas plantas. Todas as medições de trocas gasosas e fluorescência foram feitas respeitando o delineamento em blocos casualizados. A estresse hídrico afetou a fotossíntese líquida, condutância estomática, taxa transpiratória e eficiência do uso da água. Já deficiência de nitrogênio não afetou as variáveis avaliadas. As cultivares Acauã e Mundo Novo sofreram os maiores efeitos do déficit hídrico. De maneira geral, o déficit hídrico afetou as variáveis fisiológicas avaliadas enquanto a deficiência de N não afetou significativamente as variáveis fisiológicas avaliadas

Avaliação de risco ambiental estimado pela exposição ao óxido de grafeno.

O objetivo deste trabalho foi determinar valores de concentração sem efeito previsível (PNEC) para óxido de grafeno (GO), considerando a presença ou ausência de ácido húmico no meio aquático. Para isso, foram realizados testes toxicológicos e determinados os valores de concentração de efeito não observado (CENO) para 9 organismos. A PNEC de GO no compartimento aquático, abaixo da qual os efeitos adversos provavelmente não ocorrerão durante a exposição a longo ou curto prazo, foi estimada em 20 ?g/L (na ausência de ácido húmico) e 5 ?g/L (na presença de ácido húmico). Estes dados contribuem para avaliação de risco da nanotecnologia. ?- The objective of this work was to estimate the predicted no effect concentration (PNEC) for grapheme oxide (GO), considering the presence or absence of humic acid in the aquatic environment. Therefore, toxicological tests were performed and the values of no observed effect concentration (NOEC) for 9 organisms were determined. PNEC of GO in the aquatic compartment, below which adverse effects are unlikely to occur during long- or short-term exposure, was estimated at 20 ?g /L (in the absence of humic acid) and 5 ?g/L (in the presence of acid humic). These data contribute to the risk assessment of nanotechnology

The European cross-border health data exchange roadmap: case study in the Italian setting

Health data exchange is a major challenge due to the sensitive information and the privacy issues entailed. Considering the European context, in which health data must be exchanged between different European Union (EU) Member States, each having a different national regulatory framework as well as different national healthcare structures, the challenge appears even greater. Europe has tried to address this challenge via the epSOS (“Smart Open Services for European Patients”) project in 2008, a European large-scale pilot on cross-border sharing of specific health data and services. The adoption of the framework is an ongoing activity, with most Member States planning its implementation by 2020. Yet, this framework is quite generic and leaves a wide space to each EU Member State regarding the definition of roles, processes, workflows and especially the specific integration with the National Infrastructures for eHealth. The aim of this paper is to present the current landscape of the evolving eHealth infrastructure for cross-border health data exchange in Europe, as a result of past and ongoing initiatives, and illustrate challenges, open issues and limitations through a specific case study describing how Italy is approaching its adoption and accommodates the identified barriers. To this end, the paper discusses ethical, regulatory and organizational issues, also focusing on technical aspects, such as interoperability and cybersecurity. Regarding cybersecurity aspects per se, we present the approach of the KONFIDO EU-funded project, which aims to reinforce trust and security in European cross-border health data exchange by leveraging novel approaches and cutting-edge technologies, such as homomorphic encryption, photonic Physical Unclonable Functions (p-PUF), a Security Information and Event Management (SIEM) system, and blockchain-based auditing. In particular, we explain how KONFIDO will test its outcomes through a dedicated pilot based on a realistic scenario, in which Italy is involved in health data exchange with other European countries