209 research outputs found

    A análise de etilenotiouréia em mamão evita resultados falso positivos de resíduos de etileno(bis)ditiocarbamatos.

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    O principal produto de degradação de etileno(bisditiocarbamatos) (EBDCs) é a etilenotiouréia (ETU), que teoricamente pode estar presente em qualquer cultura tratada com esses fungicidas. A formação endógena de CS2 na família das Caricaceas é um fato comprovado e tem conduzido à conclusão errônea da presença de resíduos de EBDCs. Portanto, é necessário estabelecer um procedimento confirmatório para confirmar a presença desses resíduos, sendo uma possibilidade a determinação dos resíduos do seu metabólito ETU. O objetivo deste trabalho foi determinar os resíduos de ETU e de EBDCs em frutos de mamoeiro que receberam tratamento em campo com o fungicida mancozeb

    Resíduos de mancozebe e etu em mamão: efeito do tratamento hidrotérmico pós-colheita.

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    O mancozebe é um fungicida não sistêmico, e seus resíduos devem ser diferentes em frutos que recebam ou não o tratamento hidrotérmico, por sua remoção da superfície dos frutos. Por outro lado uma das preocupações quanto à sua toxicologia é a formação de um produto de transformação, favorecido pela temperatura, a etilenotiouréia (ETU). A ETU é estável em água e é rapidamente absorvida e metabolizada pelas plantas mas, não é estável quando exposta a matrizes de produtos agrícolas. Os seus resíduos são estabelecidos em 50 µg kg-1 (50ppb) pela União Européia. O objetivo deste trabalho foi avaliar o efeito do tratamento hidrotérmico nos resíduos de mancozebe e de ETU em mamão após aplicações sucessivas de mancozebe

    Molecular characterisation of sporadic endolymphatic sac tumours and comparison to von Hippel–Lindau disease‐related tumours

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    Aims: Although inactivation of the von Hippel-Lindau gene (VHL) on chromosome 3p25 is considered to be the major cause of hereditary endolymphatic sac tumours (ELSTs), the genetic background of sporadic ELST is largely unknown. The aim of this study was to determine the prevalence of VHL mutations in sporadic ELSTs and compare their characteristics to VHL-disease-related tumours. Methods: Genetic and epigenetic alterations were compared between 11 sporadic and 11 VHL-disease-related ELSTs by targeted sequencing and DNA methylation analysis. Results: VHL mutations and small deletions detected by targeted deep sequencing were identified in 9/11 sporadic ELSTs (82%). No other cancer-related genetic pathway was altered except for TERT promoter mutations in two sporadic ELST and one VHL-disease-related ELST (15%). Loss of heterozygosity of chromosome 3 was found in 6/10 (60%) VHL-disease-related and 10/11 (91%) sporadic ELSTs resulting in biallelic VHL inactivation in 8/10 (73%) sporadic ELSTs. DNA methylation profiling did not reveal differences between sporadic and VHL-disease-related ELSTs but reliably distinguished ELST from morphological mimics of the cerebellopontine angle. VHL patients were significantly younger at disease onset compared to sporadic ELSTs (29 vs. 52 years, p < 0.0001, Fisher's exact test). VHL-disease status was not associated with an increased risk of recurrence, but the presence of clear cells was found to be associated with shorter progression-free survival (p = 0.0002, log-rank test). Conclusion: Biallelic inactivation of VHL is the main mechanism underlying ELSTs, but unknown mechanisms beyond VHL may rarely be involved in the pathogenesis of sporadic ELSTs

    Institutionalisation of Social Movements: Co-option And Democratic Policy-making

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    Over the past 30 years, urban policy in Brazil has undergone a major transformation, both in terms of regulatory frameworks and the involvement of citizens in the process of policy-making. As an intense process of institutional innovation and mobilisation for decent publicservices took place, academics started to consider the impact of institutionalisation on the autonomy of social movements. Using empirical evidence from a city in the northeast of Brazil, this article addresses the wider literature on citizen participation and social movements to examine specifically the problem with co-optation. I examine the risks linked to co-optation, risks that can undermine the credibility of social movements as agents of change, and explore the tensions that go beyond the ‘co-optation versus autonomy’ divide, an issue frequently found in the practices of social movements, in their dealings with those in power. In particular, this article explores the learning processes and contentious relationships between mainly institutionally oriented urban movements and local government. This study found that the learning of deliberative skills not only led to changes in the objectives and repertoires of housing movements, but also to the inclusion of new components in their objectives that provide room for creative agency and which, in some cases, might allow them to maintain their autonomy from the state

    Molecular and translational advances in meningiomas.

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    Meningiomas are the most common primary intracranial neoplasm. The current World Health Organization (WHO) classification categorizes meningiomas based on histopathological features, but emerging molecular data demonstrate the importance of genomic and epigenomic factors in the clinical behavior of these tumors. Treatment options for symptomatic meningiomas are limited to surgical resection where possible and adjuvant radiation therapy for tumors with concerning histopathological features or recurrent disease. At present, alternative adjuvant treatment options are not available in part due to limited historical biological analysis and clinical trial investigation on meningiomas. With advances in molecular and genomic techniques in the last decade, we have witnessed a surge of interest in understanding the genomic and epigenomic landscape of meningiomas. The field is now at the stage to adopt this molecular knowledge to refine meningioma classification and introduce molecular algorithms that can guide prediction and therapeutics for this tumor type. Animal models that recapitulate meningiomas faithfully are in critical need to test new therapeutics to facilitate rapid-cycle translation to clinical trials. Here we review the most up-to-date knowledge of molecular alterations that provide insight into meningioma behavior and are ready for application to clinical trial investigation, and highlight the landscape of available preclinical models in meningiomas
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