103 research outputs found

    Repercussões do tempo operatório em pulmões de ratos idosos

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    A duração das operações pode representar um fator importante para uma série de complicações pós-operatórias, especialmente para os indivíduos idosos. Objetivo: estudar a repercussão nos pulmões, de operações de diferentes tempos de duração. Métodos: Vinte ratos idosos (18 meses) e 20 jovens (3 meses) foram separados aleatoriamente em grupos A e B respectivamente. Os grupos foram divididos em A1, A2, A3, A4, B1, B2, B3 and B4, com cinco ratos cada. Os animais foram anestesiados com pentobarbital (20mg/Kg) intraperitoneal. No subgrupo A1 e B1 foi feita operação com duração de 30 minutos, nos grupos A2 and B2 60 minutos, em A3 and B3 a operação foi feita em 120 minuto e os animais A4 e B4 (controle) não foram operados. O procedimento consistiu de laparotomia xifopubiana que foi aberta e fechada tantas vezes quanto necessário para atingir os tempos estipulados. Após o quinto dia pós-operatório os animais foram mortos com superdose de anestésico e biópsias de ambos os pulmões foram realizadas. Os achados histopatológicos foram transformados em escores. Resultados: os grupos de ratos jovens atingiram os escores: A1= escore 6, A2=11; A3=28; A4=5. Os ratos idosos tiveram os escores: B1=12; B2=34; B3=51 e B4=6. A análise estatística revelou diferenças significantes entre os escores dos grupos A e B. Conclusões: O tempo prolongado nas operações realizadas em ratos idosos contribuiu para o aparecimento de alterações pulmonares de modo significante. Quanto maior o tempo operatório, mais intensas e mais freqüentes as complicações pulmonare

    Relationship between oxidative stress and diabetic osteopenia in premenopausal rats

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    A relação entre peroxidação lipídica, defesa antioxidante e osteopenia diabética permanece obscura. Este estudo avaliou a associação entre índice de peroxidação lipídica, parâmetro de defesa antioxidante e metabolismo ósseo em um modelo diabético pré-menopausa através de medidas como a concentração de substâncias reativas ao ácido tiobarbitúrico (SRAT) e conteúdo de glutationa reduzida (GSH) no homogenato cerebral, análises histomorfométricas, teste biomecânico e densidade mineral óssea (DMO). Ratos Wistar fêmeas com ciclo estral regular foram distribuídos em dois grupos: Grupo 1 - ratas controle (n = 15) e Grupo 2 - ratas diabéticas (n = 15). O diabetes foi induzido pela aloxana e confirmado pela glicemia >250 mg/dL. O índice de peroxidação lipídica, medido pela concentração de SRAT, demonstrou um aumento significativo (pThe relationship between lipid peroxidation, antioxidant defense and diabetic osteopenia remains unclear. This study evaluated the relationship among lipid peroxidation index, antioxidant defense parameters and bone metabolism in a premenopausal diabetic model using measures including thiobarbituric acid-reactive substances concentration (TBARS) and reduced glutathione (GSH) content in brain homogenates, histomorphometric analysis, biomechanical testing and bone mineral density (BMD). Female Wistar rats with regular estrous cycle were divided into two groups: Group 1: control rats (n = 15) and Group 2: diabetic rats (n = 15). Diabetes was induced by alloxan and confirmed by glycemia >250 mg/dL. The lipid peroxidation index, measured by TBARS concentration, showed a significant increase (

    Comparison between low-cost passive and active vision for obstacle depth

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    Obstacle detection is a key issue in many current applications, especially in applications that have been increasingly highlighted such as: advanced driver assistance systems (ADAS), simultaneous localization and mapping (SLAM) and autonomous navigation system. This can be achieved by active and passive acquisition vision systems, for example: laser and cameras respectively. In this paper we present a comparison between low-cost active and passive devices, more specifically LIDAR and two cameras. To this comparison a disparity map is created by stereo correspondence through two images and a point cloud map created by LIDAR data values (distances measures). The obtained results shown that passive vision can be as good as or even better than active vision in low cost scenarios

    Comparison between low-cost passive and active vision for obstacle depth

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    Obstacle detection is a key issue in many current applications, especially in applications that have been increasingly highlighted such as: advanced driver assistance systems (ADAS), simultaneous localization and mapping (SLAM) and autonomous navigation system. This can be achieved by active and passive acquisition vision systems, for example: laser and cameras respectively. In this paper we present a comparison between low-cost active and passive devices, more specifically LIDAR and two cameras. To this comparison a disparity map is created by stereo correspondence through two images and a point cloud map created by LIDAR data values (distances measures). The obtained results shown that passive vision can be as good as or even better than active vision in low cost scenarios

    Comparison between low-cost passive and active vision for obstacle depth

    Get PDF
    Obstacle detection is a key issue in many current applications, especially in applications that have been increasingly highlighted such as: advanced driver assistance systems (ADAS), simultaneous localization and mapping (SLAM) and autonomous navigation system. This can be achieved by active and passive acquisition vision systems, for example: laser and cameras respectively. In this paper we present a comparison between low-cost active and passive devices, more specifically LIDAR and two cameras. To this comparison a disparity map is created by stereo correspondence through two images and a point cloud map created by LIDAR data values (distances measures). The obtained results shown that passive vision can be as good as or even better than active vision in low cost scenarios

    Heart and systemic effects of statin pretreatment in a rat model of abdominal sepsis. Assessment by Tc99m-sestamibi biodistribition

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    PURPOSE: To evaluate the heart and the Tc-99m-sestamibi biodistribution after statin pretreatment in a rat model of abdominal sepsis. METHODS: Twenty-four Wistar rats were randomly distributed into four groups (n=6 per group): 1) sepsis with simvastatin treatment, 2) sepsis with vehicle, 3) sham control with simvastatin and 4) sham control with vehicle. 24 hours after cecal ligation and puncture rats received 1.0MBq of Tc-99m-sestamibi i.v. 30min after, animals were euthanized for ex-vivo tissue counting and myocardium histological analysis. RESULTS: Myocardial histologic alterations were not detected 24 hours post-sepsis. There was significantly increased cardiac Tc-99m-sestamibi activity in the sepsis group with simvastatin treatment (1.9±\pm0.3%ID/g, p<0.001) in comparison to the sepsis group+vehicle (1.0±\pm0.2% ID/g), control sham group+ simvastatin (1.2±\pm0.3% ID/g) and control sham group (1.3±\pm0.2% ID/g). Significant Tc-99m-sestamibi activity in liver, kidney and lungs was also detected in the sepsis group treated with simvastatinin comparison to the other groups. CONCLUSIONS: Statin treatment altered the biodistribution of Tc-99m-sestamibi with increased cardiac and solid organ activity in rats with abdominal sepsis, while no impact on controls. Increased myocardial tracer activity may be a result of a possible protection effect due to increased tissue perfusion mediated by statins

    Exploring low-energy neutrino physics with the Coherent Neutrino Nucleus Interaction Experiment

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    The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charge-coupled devices (CCDs) with the goal of measuring low-energy recoils from coherent elastic scattering ( CE ν NS ) of reactor antineutrinos with silicon nuclei and testing nonstandard neutrino interactions (NSI). We report here the first results of the detector array deployed in 2016, considering an active mass 47.6 g (eight CCDs), which is operating at a distance of 30 m from the core of the Angra 2 nuclear reactor, with a thermal power of 3.8 GW. A search for neutrino events is performed by comparing data collected with the reactor on (2.1 kg-day) and reactor off (1.6 kg-day). The results show no excess in the reactor-on data, reaching the world record sensitivity down to recoil energies of about 1 keV (0.1 keV electron equivalent). A 95% confidence level limit for new physics is established at an event rate of 40 times the one expected from the standard model at this energy scale. The results presented here provide a new window to low-energy neutrino physics, allowing one to explore for the first time the energies accessible through the low threshold of CCDs. They will lead to new constraints on NSI from the CEνNS of antineutrinos from nuclear reactors.Fil: Aguilar Arevalo, Alexis. Universidad Nacional Autónoma de México; MéxicoFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Bonifazi, Carla Brenda. Universidade Federal do Rio de Janeiro; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cancelo, Gustavo Indalecio. Fermi National Accelerator Laboratory; Estados UnidosFil: Castañeda, Alejandro. Universidad Nacional Autónoma de México; MéxicoFil: Cervantes Vergara, Brenda. Universidad Nacional Autónoma de México; MéxicoFil: Chavez, Claudio. Universidad Nacional de Asunción; ParaguayFil: D’Olivo, Juan C.. Universidad Nacional Autónoma de México; MéxicoFil: Dos Anjos, João C.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Estrada, Juan. Fermi National Accelerator Laboratory; Estados UnidosFil: Fernandes Neto, Aldo R.. Centro Federal de Educacão Tecnológica Celso Suckow Da Fonseca; BrasilFil: Fernández Moroni, Guillermo. Fermi National Accelerator Laboratory; Estados Unidos. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Foguel, Ana. Universidade Federal do Rio de Janeiro; BrasilFil: Ford, Richard. Fermi National Accelerator Laboratory; Estados UnidosFil: Gonzalez Cuevas, Juan. Universidad Nacional de Asunción; ParaguayFil: Hernández, Pamela. Universidad Nacional Autónoma de México; MéxicoFil: Hernandez, Susana. Fermi National Accelerator Laboratory; Estados UnidosFil: Izraelevitch, Federico Hernán. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kavner, Alexander R.. University of Michigan; Estados UnidosFil: Kilminster, Ben. Universitat Zurich; SuizaFil: Kuk, Kevin. Fermi National Accelerator Laboratory; Estados UnidosFil: Lima, H.P.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Makler, Martín. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Molina, Jorge. Universidad Nacional de Asunción; ParaguayFil: Mota, Philipe. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Nasteva, Irina. Universidade Federal do Rio de Janeiro; BrasilFil: Paolini, Eduardo Emilio. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Romero, Carlos. Universidad Nacional de Asunción; ParaguayFil: Sarkis, Y.. Universidad Nacional Autónoma de México; MéxicoFil: Sofo Haro, Miguel Francisco. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de Cuyo; Argentina. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnol.conicet - Patagonia Norte. Unidad de Adm.territorial; ArgentinaFil: Souza, Iruatã M. S.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Tiffenberg, Javier Sebastian. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wagner, Stefan. Centro Brasileiro de Pesquisas Físicas; Brasil. Pontifícia Universidade Católica do Rio de Janeiro; Brasi

    AI is a viable alternative to high throughput screening: a 318-target study

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    : High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
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