12 research outputs found

    Colloidal (Gd0.98Nd0.02)2O3 nanothermometers operating in a cell culture medium within the first and second biological windows

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    Non-contact, self-referenced and near-infrared luminescent nanothermometers have been recognized as emerging tools in the fields of nanomedicine and nanotechnology due to their great capability of precise temperature readout at the nanoscale and real-time deep-tissue imaging. However, the development of multifunctional and biocompatible luminescent nanothermometers operating within the optically transparent biological windows with high thermal sensitivity (>2.0%/K) remains challenging. Here, we present (Gd0.98Nd0.02)2O3 nanothermometers operated effectively within the first and second biological windows upon continuous-wave laser diode excitation at 808 nm. Ratiometric thermometric parameters are defined by the relative changes in the emission intensities originating from the two Stark components of the 4F3/2 level (R2 and R1) to the 4I9/2 (900–1000 nm), 4I11/2 (1035–1155 nm) and 4I13/2 (1300–1450 nm) multiplets. The thermometric parameters are evaluated for colloidal samples in a cell culture medium and powder samples, and the highest thermal sensitivity (2.18%/K at 298 K) is attained for the former in the first biological window (both the excitation and emission in the 800–965 nm range). The repeatability and temperature uncertainty are 99% and 1.2 K, respectively. The nanothermometers are biocompatible with human MNT-1 melanoma and HaCaT cells for 24 h of exposure and nanoparticle concentration up to 0.400 mg/mL, showing their potential for applications in nanomedicine, e.g., intracellular imaging and temperature mappingpublishe

    In vitro neurotoxicity evaluation of piperazine designer drugs in differentiated human neuroblastoma SH-SY5Y cells

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    Abuse of synthetic drugs is widespread worldwide. Studies indicate that piperazine designer drugs act as substrates at dopaminergic and serotonergic receptors and/or transporters in the brain. This work aimed to investigate the cytotoxicity of N-benzylpiperazine, 1-(3-trifluoromethylphenyl)piperazine, 1-(4-methoxyphenyl)piperazine and 1-(3,4-methylenedioxybenzyl)piperazine in the differentiated human neuroblastoma SH-SY5Y cell line. Cytotoxicity was evaluated after 24 h incubations through the MTT reduction and neutral red uptake assays. Oxidative stress (reactive oxygen and nitrogen species production and glutathione content) and energetic (ATP content) parameters, as well as intracellular Ca(2+) , mitochondrial membrane potential, DNA damage (comet assay) and cell death mode were also evaluated. Complete cytotoxicity curves were obtained after 24 h incubations with each drug. A significant decrease in intracellular total glutathione content was noted for all the tested drugs. All drugs caused a significant increase of intracellular free Ca(2+) levels, accompanied by mitochondrial hyperpolarization. However, ATP levels remained unchanged. The investigation of cell death mode revealed a predominance of early apoptotic cells. No genotoxicity was found in the comet assay. Among the tested drugs, 1-(3-trifluoromethylphenyl)piperazine was the most cytotoxic. Overall, piperazine designer drugs are potentially neurotoxic, supporting concerns on risks associated with the abuse of these drugs. Copyright © 2015 John Wiley & Sons, Ltd.Marcelo Dutra Arbo is the recipient of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES Foundation – Brazil) fellowship (Proc. BEX 0593/10-9). Renata Silva and Daniel José Barbosa were supported by fellowships (SFRH/BD/29559/2006 and SFRH/BD/64939/2009, respectively) from Fundação para a Ciência e Tecnologia (FCT), Portugal. This work was supported by the European Union (FEDER funds through COMPETE – Operational Programme for Competitiveness Factors) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through the project Pest-C/EQB/LA0006/2013. The work also received financial support from the European Union (FEDER funds under the framework of QREN through Project NORTE-07-0124-FEDER-000067

    A practical framework and online tool for mutational signature analyses show intertissue variation and driver dependencies

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    Mutational signatures are patterns of mutations that arise during tumorigenesis. We present an enhanced, practical framework for mutational signature analyses. Applying these methods to 3,107 whole-genome-sequenced (WGS) primary cancers of 21 organs reveals known signatures and nine previously undescribed rearrangement signatures. We highlight interorgan variability of signatures and present a way of visualizing that diversity, reinforcing our findings in an independent analysis of 3,096 WGS metastatic cancers. Signatures with a high level of genomic instability are dependent on TP53 dysregulation. We illustrate how uncertainty in mutational signature identification and assignment to samples affects tumor classification, reinforcing that using multiple orthogonal mutational signature data is not only beneficial, but is also essential for accurate tumor stratification. Finally, we present a reference web-based tool for cancer and experimentally generated mutational signatures, called Signal (https://signal.mutationalsignatures.com), that also supports performing mutational signature analyses

    Dietas com nitrogênio não-proteico para fêmeas bovinas superovuladas sem prévia adaptação durante curto tempo e em diferentes fases do ciclo estral Effect of short term non-protein nitrogen feeding for superovulated beef cows without previous adaptation and at different periods of the oestrus cycle

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    Objetivou-se neste estudo avaliar o efeito do fornecimento, sem prévia adaptação, durante curto tempo e em diferentes fases do ciclo estral, de dietas contendo nitrogênio não-proteico (NNP) na produção, na qualidade e no grau de desenvolvimento de embriões recuperados em fêmeas bovinas superovuladas. Sessenta e oito vacas Nelore foram distribuídas em três grupos: um controle e dois com fornecimento de ureia antes (UA = do dia -5 ao dia 0) e após (UD = dia 0 ao dia 5) a inseminação artificial. As vacas foram mantidas em pastagem e receberam concentrado (3,0 kg/animal/dia) durante 16 dias. Foram formulados dois concentrados, e as dietas totais (concentrado e consumo estimado de pastagem) apresentaram 12,0% (dieta controle) e 14,6% (dieta NNP) de proteína bruta (PB). As vacas foram sincronizadas, superovuladas e inseminadas. Sete dias (dia 7) após a inseminação (dia 0), realizou-se a colheita e análise dos embriões. Amostras de sangue foram coletadas nos dias -5, 0 e 5 para determinação da concentração de nitrogênio ureico plasmático (NUP), glicose, insulina e progesterona. A época de fornecimento de ureia influenciou as concentrações médias de NUP nos dias -5, 0 e 5, mas não tiveram efeito nas concentrações de glicose, insulina e progesterona. O período de fornecimento da ureia teve efeito na porcentagem de mórulas compactas em relação ao total de estruturas (UA = 51,4 vs. UD = 15,3%), em relação ao total de oócitos fecundados (UA = 62,5 vs. UD = 30,6%) e em relação ao total de embriões viáveis (UA = 68,8 vs. UD = 38,6%). No grupo que recebeu ureia depois da inseminação artificial, houve redução de 70,2% da proporção de mórulas compactas por total de estruturas em relação ao grupo que recebeu ureia antes da inseminação. Dietas com nitrogênio não-proteico fornecidas imediatamente após a inseminação promovem aceleração do desenvolvimento embrionário inicial.<br>The aim of this study was to evaluate the effects of short term non-protein nitrogen feeding at different periods of the oestrus cycle in superovulated cows, without previous adaptation, on yield, quality and development degree of recovered embryos. A total of sixty-eight Nelore cows were distributed in three groups: the control group (C) and two groups with urea supply before (UB; urea supply from day -5 to day 0) and after (UA; supply from day 0 to day 5) artificial insemination. Animals were kept grazing and received 3.0 kg/animal/day of concentrate during 16 days. Two concentrates were formulated and the total diets (concentrate and estimate forage intake) showed 12.0% (control diet) and 14.6% (non-protein diet) of crude protein. Animals were synchronized, superovulated and inseminated. The embryos were collected and analysed seven days (day 7) after insemination (day 0). Blood samples were collected on days -5, 0 and 5 to determine concentration of plasmatic urea nitrogen, glucose, insulin and progesterone. The time of urea supply affected average plasmatic urea nitrogen concentration on days -5, 0 5 but it did not affect concetrations of glucose, insulin and progesterone. The moment of urea inclusion had effect on compact morula percentage in relation to the total number of structures (UB = 51.4 vs. UA = 15.3%), to the total number of fertilized oocytes (UB = 62.5 vs. UA = 30.6%) and to the total number of viable embryos (UB = 68.8 vs. UA = 38.6%). In the after insemination group of urea supply there was 70.2% of reduction on compact morula proportion over the total structures in relation to the group that received urea before insemination. Non-protein nitrogen feeding immediately after insemination promotes faster rates of embryo development

    Evolução de atributos físicos de solo em sistema de integração lavoura-pecuária

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    O objetivo deste trabalho foi avaliar o efeito das alturas de pastejo e dos sucessivos ciclos de pastejo sobre os atributos físicos do solo, em um sistema de integração lavoura-pecuária. O experimento foi implantado em 2001, na região do Planalto Médio, RS, em um Latossolo Vermelho, com o cultivo consorciado de azevém (Lolium multiflorum) e de aveia-preta (Avena strigosa), sob pastejo contínuo, no inverno, e o cultivo de soja (Glycine max) no verão. Os tratamentos consistiram de diferentes intensidades de pastejo, definidas pela altura da pastagem (10, 20, 30 e 40 cm), tendo-se utilizado uma área sem pastejo como controle. Foram avaliadas a densidade e a porosidade do solo após o ciclo de pastejo e de cultivo da soja, bem como a resistência mecânica do solo à penetração e a estabilidade de agregados no sétimo ano do experimento. Não houve alterações significativas na densidade e na porosidade do solo após sete anos em integração lavoura-pecuária. A resistência do solo à penetração é maior na camada superficial após o ciclo de pastejo. A agregação do solo aumenta nas áreas pastejadas, independentemente da intensidade de pastejo
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