203 research outputs found
Uma abordagem comparativa de algoritmos de aprendizado supervisionado para classificação dos cultivares da planta Paullinia cupana.
O guaranazeiro (Paullinia cupana) vem sendo estudado pela Embrapa Amazonia Ocidental desde o final da década de 70, resultando no desenvolvimento e disponibilizac¸ao de 19 cultivares resistentes as principais pragas e doenças. Contudo, a distinção dentre esses espécimes ainda é restrita a procedimentos manuais e técnicos, sujeitos à falha humana. Dessa forma, buscou-se identificar os melhores métodos de aprendizado supervisionado para o contexto de classificação desses cultivares a partir de imagens de suas folhas. Das técnicas utilizadas como Árvores de Decisao, Maquinas de Vetores de Suporte e Redes Neurais Convolucionais, essa última obteve melhor performance alcançando 89,6% de acurácia
Classificação de guaranazeiros através do padrão de venação e formato de folíolos utilizando aprendizagem de máquina.
O guaranazeiro é uma importante fonte de renda para estados amazônicos que o cultivam, porém sua produção é afetada devido à proliferação de pragas e doenças locais. Embrapa, então, lançou cultivares resistentes aos principais problemas que afetam a guaranaicultura na Amazônia, mas o processo de identificação desses cultivares são manuais, custosos e carente de recursos humanos. Assim, este trabalho buscou comparar técnicas de aprendizagem de máquinas como Florestas Aleatórias, Máquinas de Vetores de Suporte e Redes Perceptron aplicadas à tarefa de classificação desses cultivares, através do padrão da nervura e formato dos folíolos. Os resultados apresentam-se estáveis e satisfatórios, sugerindo uma nova perspectiva para o problema em questão
A Combination of Approved Antibodies Overcomes Resistance of Lung Cancer to Osimertinib by Blocking Bypass Pathways.
<b>Purpose:</b> Because of emergence of resistance to osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), no targeted treatments are available for patients with lung cancer who lose sensitivity due to new mutations or bypass mechanisms. We examined in animals and <i>in vitro</i> an alternative therapeutic approach making use of antibodies. <b>Experimental Design:</b> An osimertinib-sensitive animal model of lung cancer, which rapidly develops drug resistance, has been employed. To overcome compensatory hyperactivation of ERK, which we previously reported, an anti-EGFR antibody (cetuximab) was combined with other antibodies, as well as with a subtherapeutic dose of osimertinib, and cancer cell apoptosis was assayed. <b>Results:</b> Our animal studies identified a combination of three clinically approved drugs, cetuximab, trastuzumab (an anti-HER2 mAb), and osimertinib (low dose), as an effective and long-lasting treatment that is able to prevent onset of resistance to osimertinib. A continuous schedule of concurrent treatment was sufficient for effective tumor inhibition and for prevention of relapses. Studies employing cultured cells and analyses of tumor extracts indicated that the combination of two mAbs and a subtherapeutic TKI dose sorted EGFR and HER2 for degradation; cooperatively enhanced apoptosis; inhibited activation of ERK; and reduced abundance of several bypass proteins, namely MET, AXL, and HER3. <b>Conclusions:</b> Our <i>in vitro</i> assays and animal studies identified an effective combination of clinically approved drugs that might overcome resistance to irreversible TKIs in clinical settings. The results we present attribute the long-lasting effect of the drug combination to simultaneous blockade of several well-characterized mechanisms of drug resistance. <i>Clin Cancer Res; 24(22); 5610-21. ©2018 AACR</i> <i>See related commentary by Fan and Yu, p. 5499</i>
Effect of chitosan essential oil films on the storage-keeping quality of pork meat products
Edible films based on chitosan were prepared, with
and without basil or thyme essential oils, with the aim of
assessing their protective ability against lipid oxidation and
their antimicrobial activity. Chitosan films had good oxygenbarrier
properties, which were worsened by essential oil addition,
especially when the film equilibrium moisture content
increased. Due to the oxygen-barrier effect, all the films
effectively protected pork fat from oxidation, in comparison
to unprotected samples. In spite of the worsening of the
oxygen-barrier properties, the films with essential oils were
more effective than those of pure chitosan, which points to the
chemical action of specific antioxidant compounds of the oils.
Films were effective to control microbial growth in minced
pork meat, although the incorporation of essential oils did not
improve their antimicrobial activity. Throughout the storage,
the films led to colour changes in minced pork meat associated
with the conversion of myoglobin into metmyoglobin due to
the reduction of the oxygen availability.The authors acknowledge the financial support provided by the Universitat Politecnica de Valencia (PAID-06-09-2834), Generalitat Valenciana (GV/2010/082) and Ministerio de Educacion y Ciencia (AGL2010-20694). Author J. Bonilla is deeply grateful to Generalitat Valenciana for a Santiago Grisolia Grant.Bonilla Lagos, MJ.; Vargas, M.; Atarés Huerta, LM.; Chiralt Boix, MA. (2014). Effect of chitosan essential oil films on the storage-keeping quality of pork meat products. Food and Bioprocess Technology. 7(8):2443-2450. https://doi.org/10.1007/s11947-014-1329-3S2443245078ASTM D3985. (1995). Standard test method for oxygen gas transmission rate through plastic films and sheeting using a coulometric sensor. West Conshohocken: American Society for Testing and Materials.Atarés, L., Pérez-Masiá, R., & Chiralt, A. (2011). The role of some antioxidants in the HPMC film properties and lipid protection in coated toasted almonds. 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Trials
BACKGROUND: Postoperative upper gastrointestinal fistula (PUGIF) is a devastating complication, leading to high mortality (reaching up to 80%), increased length of hospital stay, reduced health-related quality of life and increased health costs. Nutritional support is a key component of therapy in such cases, which is related to the high prevalence of malnutrition. In the prophylactic setting, enteral nutrition (EN) is associated with a shorter hospital stay, a lower incidence of severe infectious complications, lower severity of complications and decreased cost compared to total parenteral nutrition (TPN) following major upper gastrointestinal (GI) surgery. There is little evidence available for the curative setting after fistula occurrence. We hypothesize that EN increases the 30-day fistula closure rate in PUGIF, allowing better health-related quality of life without increasing the morbidity or mortality. METHODS/DESIGN: The NUTRILEAK trial is a multicenter, randomized, parallel-group, open-label phase III trial to assess the efficacy of EN (the experimental group) compared with TPN (the control group) in patients with PUGIF. The primary objective of the study is to compare EN versus TPN in the treatment of PUGIF (after esophagogastric resection including bariatric surgery, duodenojejunal resection or pancreatic resection with digestive tract violation) in terms of the 30-day fistula closure rate. Secondary objectives are to evaluate the 6-month postrandomization fistula closure rate, time of first fistula closure (in days), the medical- and surgical treatment-related complication rate at 6 months after randomization, the fistula-related complication rate at 6 months after randomization, the type and severity of early (30 days after randomization) and late fistula-related complications (over 30 days after randomization), 30-day and 6-month postrandomization mortality rate, nutritional status at day 30, day 60, day 90 and day 180 postrandomization, the mean length of hospital stay, the patient's health-related quality of life (by self-assessment questionnaire), oral feeding time and direct costs of treatment. A total of 321 patients will be enrolled. DISCUSSION: The two nutritional supports are already used in daily practice, but most surgeons are reluctant to use the enteral route in case of PUGIF. This study will be the first randomized trial testing the role of EN versus TPN in PUGIF. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03742752. Registered on 14 November 2018.This research program is funded by the French Ministry of Health through Programme Hospitalier de Recherche Clinique 2016
Uma abordagem comparativa de algoritmos de aprendizado supervisionado para classificação dos cultivares da planta Paullinia cupana.
O guaranazeiro (Paullinia cupana) vem sendo estudado pela Embrapa Amazonia Ocidental desde o final da década de 70, resultando no desenvolvimento e disponibilizac¸ao de 19 cultivares resistentes as principais pragas e doenças. Contudo, a distinção dentre esses espécimes ainda é restrita a procedimentos manuais e técnicos, sujeitos à falha humana. Dessa forma, buscou-se identificar os melhores métodos de aprendizado supervisionado para o contexto de classificação desses cultivares a partir de imagens de suas folhas. Das técnicas utilizadas como Árvores de Decisao, Maquinas de Vetores de Suporte e Redes Neurais Convolucionais, essa última obteve melhor performance alcançando 89,6% de acurácia.Made available in DSpace on 2018-07-25T01:18:15Z (GMT). No. of bitstreams: 1
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Previous issue date: 2018-07-24bitstream/item/180210/1/revista-TC-final-Allex.pd
Indução de hipóteses a partir de experiência passada com imagens para identificação de espécimes vegetais.
Propõe-se uma abordagem semelhante, mas aplicada a uma ferramenta capaz de auxiliar a tomada de decisão por parte de profissionais e pesquisadores do setor agronômico, através de uma solução móvel para a plataforma Android
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