Automated recognition of lung diseases in CT images based on the optimum-path forest classifier

The World Health Organization estimated that around 300 million people have asthma, and 210 million people are affected by Chronic Obstructive Pulmonary Disease (COPD). Also, it is estimated that the number of deaths from COPD increased 30% in 2015 and COPD will become the third major cause of death worldwide by 2030. These statistics about lung diseases get worse when one considers fibrosis, calcifications and other diseases. For the public health system, the early and accurate diagnosis of any pulmonary disease is mandatory for effective treatments and prevention of further deaths. In this sense, this work consists in using information from lung images to identify and classify lung diseases. Two steps are required to achieve these goals: automatically extraction of representative image features of the lungs and recognition of the possible disease using a computational classifier. As to the first step, this work proposes an approach that combines Spatial Interdependence Matrix (SIM) and Visual Information Fidelity (VIF). Concerning the second step, we propose to employ a Gaussian-based distance to be used together with the optimum-path forest (OPF) classifier to classify the lungs under study as normal or with fibrosis, or even affected by COPD. Moreover, to confirm the robustness of OPF in this classification problem, we also considered Support Vector Machines and a Multilayer Perceptron Neural Network for comparison purposes. Overall, the results confirmed the good performance of the OPF configured with the Gaussian distance when applied to SIM- and VIF-based features. The performance scores achieved by the OPF classifier were as follows: average accuracy of 98.2%, total processing time of 117 microseconds in a common personal laptop, and F-score of 95.2% for the three classification classes. These results showed that OPF is a very competitive classifier, and suitable to be used for lung disease classification

Atividade tripanocida de flavonoides e limonoides isolados de extratos ativos de plantas de Myrsinaceae e Meliaceae

The activity of crude extracts of three Rapanea species (Myrsinaceae) and Cipadessa fruticosa (Meliaceae) was evaluated in vitro against the trypomastigote forms of Trypanosoma cruzi. Thirty-three extracts from different organs of these species were assayed and eleven of them showed significant activity (lysis % >50). The fractionation of an active extract from branches of R. lancifolia (99.5%) led to the isolation of two flavonoids: quercetin and taxifolin, which have weak trypanocidal activity. Additionally, one active extract from fruits of C. fruticosa (97.7%) afforded mexicanolide limonoids: cipadesin, mexicanolide, febrifugin and cipadesin A, that were slightly active on T. cruzi. Moreover, other two flavonoids (flavone and 7-methoxyflavone), previously assayed against T. cruzi, were isolated from the hexane extract from branches of C. fruticosa (100%). The results presented here suggest that the plants evaluated could be a source of new active compounds against T. cruzi.A atividade de extratos brutos de três espécies de Rapanea (Myrsinaceae) e de Cipadessa fruticosa (Meliaceae) foi avaliada in vitro contra formas tripomastigotas de Trypanosoma cruzi. Foram obtidos 33 extratos de diferentes órgãos das espécies estudadas, sendo que onze deles apresentaram atividades significantes (% de lise > 50) nos ensaios realizados. O fracionamento de um extrato ativo dos galhos de R. lancifolia (99,5%) resultou no isolamento de dois flavonoides (quercetina e taxifolina), que apresentaram baixa atividade tripanocida. De um extrato ativo dos frutos de C. fruticosa (97,7%) foram isolados os limonoides mexicanolídeos cipadesina, mexicanolídeo, febrifugina e cipadesina A, que foram moderadamente ativos sobre T. cruzi. Além disso, outros dois flavonoides (flavona e 7-metoxiflavona), previamente ensaiados contra T. cruzi, foram isolados do extrato hexânico dos galhos de C. fruticosa (100%). Os resultados obtidos aqui sugerem que as plantas avaliadas podem constituir fontes de novas substâncias ativas sobre o T. cruzi.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES)FINEP - Financiadora de Estudos e Projeto

Magnetic field strength and orientation effects on Co-Fe discontinuous multilayers close to percolation

Magnetization and magnetoresistance in function of the magnitude and orientation of applied magnetic field were studied in Co-Fe discontinuous multilayers close to their structural percolation. The high pulsed magnetic fields up to 33 T were used in the 120–310 K temperature range. Comparison between longitudinal and transverse (with respect to the film plane) field configurations was made in the low-field and high-field regimes in order to clarify the nature of the measured negative magnetoresistance. Coexistence of two distinct magnetic fractions, superparamagnetic (SPM, consisting of small spherical Co-Fe granules) and superferromagnetic (SFM, by bigger Co-Fe clusters), was established in this system. These fractions were shown to have different relevance for the system magnetization and magnetotransport. While the magnetization is almost completely (up to ∼97%) defined by the SFM contribution and practically independent of temperature (in this range), the magnetoresistance experiences a crossover from a regime dominated by Langevin correlations (suppressed with temperature) between neighbor SPM and SFM moments at low fields, to that dominated by spin scattering (enhanced with temperature) of charge carriers within SFM clusters at high fields. Also, the demagnetizing effects, sensitive to the field orientation, were found to essentially define the low-field behavior and characteristic crossover field

Busca de inibidores da enzima glicossomal gliceraldeído 3-fosfato desidrogenase de Trypanosoma cruzi

The inhibitory activity of crude extracts of Meliaceae and Rutaceae plants on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) enzyme from Trypanosoma cruzi was evaluated at 100 μg/mL. Forty-six extracts were tested and fifteen of them showed significant inhibitory activity (IA % > 50). The majority of the assayed extracts of Meliaceae plants (Cedrela fissilis, Cipadessa fruticosa and Trichilia ramalhoi) showed high ability to inhibit the enzymatic activity. The fractionation of the hexane extract from branches of C. fruticosa led to the isolation of three flavonoids: flavone, 7-methoxyflavone and 3',4',5',5,7-pentamethoxyflavone. The two last compounds showed high ability to inhibit the gGAPDH activity. Therefore, the assayed Meliaceae species could be considered as a promising source of lead compounds against Chagas' disease.Nesse trabalho foi avaliada a atividade inibitória sobre a enzima glicossomal gliceraldeído-3-fosfato desidrogenase de T. cruzi (gGAPDH) de extratos vegetais oriundos de plantas das famílias Meliaceae e Rutaceae, na concentração de 100 μg/mL. Foram testados 46 extratos, dos quais 15 apresentaram atividade inibitória significativa (% AI > 50). A maioria dos extratos de plantas da família Meliaceae (Cedrela fissilis, Cipadessa fruticosa e Trichilia ramalhoi) apresentou grande potencial em inibir a atividade enzimática. O fracionamento do extrato hexânico dos galhos de C. fruticosa permitiu o isolamento de três flavonóides: flavona, 7-metoxiflavona e 3',4',5',5,7-pentametoxiflavona. Os dois últimos foram ativos na inibição da atividade de gGAPDH. Desta forma, as três espécies de Meliaceae testadas podem ser consideradas promissoras na busca de compostos protótipos para o controle da doença de Chagas.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES)FINEP - Financiadora de Estudos e Projeto

Seasonality Role on the Phenolics from Cultivated Baccharis dracunculifolia

Baccharis dracunculifolia is the source of Brazilian green propolis (BGP). Considering the broad spectrum of biological activities attributed to green proplis, B. dracunculifolia has a great potential for the development of new cosmetic and pharmaceutical products. In this work, the cultivation of 10 different populations of native B. dracunculifolia had been undertaken aiming to determine the role of seasonality on its phenolic compounds. For this purpose, fruits of this plant were collected from populations of 10 different regions, and 100 individuals of each population were cultivated in an experimental area of 1800 m2. With respect to cultivation, the yields of dry plant, essential oil and crude extract were measured monthly resulting in mean values of 399 ± 80 g, 0.6 ± 0.1% and 20 ± 4%, respectively. The HPLC analysis allowed detecting seven phenolic compounds: caffeic acid, ferulic acid, aromadendrin-4′-methyl ether (AME), isosakuranetin, artepillin C, baccharin and 2-dimethyl-6-carboxyethenyl-2H-1-benzopyran acid, which were the major ones throughout the 1-year monthly analysis. Caffeic acid was detected in all cultivated populations with mean of 4.0%. AME displayed the wide variation in relation to other compounds showing means values of 0.65 ± 0.13% at last quarter. Isosakuranetin and artepillin C showed increasing concentrations with values between 0% and 1.4% and 0% and 1.09%, respectively. The obtained results allow suggesting that the best time for harvesting this plant, in order to obtain good qualitative and quantitative results for these phenolic compounds, is between December and April