Avaliação de citotoxicidade de nanotransportadores sem substância ativa em função da sua densidade populacional

A par da evolução da nanotecnologia, assiste-se a uma crescente preocupação sobre eventuais riscos/toxicidade que os nanotransportadores possam representar [1]. A maioria dos trabalhos publicados relativos à avaliação da citotoxicidade in vitro de nanotransportadores (NT) incide na comparação quando a substância ativa (SA) é administrada em solução ou nanoencapsulada, sendo escassos os estudos que visam avaliar a possível toxicidade do NT por si só (sem SA). O objetivo deste trabalho consistiu na avaliação da citotoxicidade de NT sem SA em função da sua densidade populacional, tendo sido testados quatro NT distintos: nanocápsulas (NC), nanoesferas (NE), transportadores lipídicos nanoestruturados (NLC) e lipossomas, com oito densidades populacionais (diluições décimais de 2,10×1012 part/mL a 2,10×105 part/mL). A avaliação da citotoxicidade realizou-se numa cultura primária (linfócitos) pelo teste do MTT e numa linha celular (fibroblastos 3T3) pelo teste do vermelho neutro (NR)

Giant Amazonian fish pirarucu (Arapaima gigas): Its viscera as a source of thermostable trypsin

A trypsin was purified from pyloric caeca of pirarucu (Arapaima gigas). the effect of metal ions and protease inhibitors on its activity and its physicochemical and kinetic properties, as well its N-terminal sequence, were determined. A single band (28.0 kDa) was observed by SDS-PAGE. Optimum pH and temperature were 9.0 and 65 degrees C, respectively. the enzyme was stable after incubation for 30 min in a wide pH range (6.0-11.5) and at 55 degrees C. the kinetic parameters K-m, k(cat) and k(cat)/K-m were 0.47 +/- 0.042 mM, 1.33 s(-1) and 2.82 s(-1) mM(-1), respectively, using BApNA as substrate. This activity was shown to be very sensitive to some metal ions, such as Fe2+, Hg2+, Zn2+, Al3+, Pb2+, and was highly inhibited by trypsin inhibitors. the trypsin N-terminal sequence IVGGYECPRNSVPYQ was found. the features of this alkaline peptidase suggest that it may have potential for industrial applications (e.g. food and detergent industries). (C) 2012 Elsevier B.V. All rights reserved.Financiadora de Estudos e Projetos (FINEP/RECAR-CINE)Ministerio da Aquicultura e Pesca (MAP)Empresa brasileira de pesquisa agropecuaria (Embrapa)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Apoio a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)Petroleo do Brasil S/A (PETROBRAS)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Fed Pernambuco, Lab Enzimol LABENZ, Dept Bioquim, BR-50670420 Recife, PE, BrazilUniv Fed Pernambuco, LIKA, BR-50670420 Recife, PE, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biofis, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biofis, BR-04044020 São Paulo, BrazilWeb of Scienc

Impact of dwell time on vertical transportation through discrete simulation in SIMIO

This work has the objective of simulating an elevator system, using SIMIO software. Firstly, two different approaches, and its implementation, will be explained and compared: Vehicle vs. Entity. After selecting the Entity-approach, due to its more flexible processes and the limitations of the Vehicle-approach, it will be used to conduct the simulation experiments. The purpose is to evaluate the impact of dwell time - time in which the elevator remains stopped, allowing for clients to enter and exit - in the performance of the system. That will be achieved analysing the impact on the total time - spent by clients from placing a call until reaching its destination - number of clients inside the system and waiting for the elevator, waiting time, elevator occupation and number of elevator movements. The analysis of the results indicates that, for the properties defined, the best time for the elevator to stay with its doors open is around 10 seconds.This work has been supported by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEst-OE/EEI/UI0319/2014 (ALGORITMI).info:eu-repo/semantics/publishedVersio

Sensibilidade e especificidade dos classificadores de aprendizagem de máquina para o diagnóstico de glaucoma usando Spectral Domain OCT e perimetria automatizada acromática

PURPOSE: To evaluate the sensitivity and specificity of machine learning classifiers (MLCs) for glaucoma diagnosis using Spectral Domain OCT (SD-OCT) and standard automated perimetry (SAP). METHODS: Observational cross-sectional study. Sixty two glaucoma patients and 48 healthy individuals were included. All patients underwent a complete ophthalmologic examination, achromatic standard automated perimetry (SAP) and retinal nerve fiber layer (RNFL) imaging with SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec Inc., Dublin, California). Receiver operating characteristic (ROC) curves were obtained for all SD-OCT parameters and global indices of SAP. Subsequently, the following MLCs were tested using parameters from the SD-OCT and SAP: Bagging (BAG), Naive-Bayes (NB), Multilayer Perceptron (MLP), Radial Basis Function (RBF), Random Forest (RAN), Ensemble Selection (ENS), Classification Tree (CTREE), Ada Boost M1(ADA),Support Vector Machine Linear (SVML) and Support Vector Machine Gaussian (SVMG). Areas under the receiver operating characteristic curves (aROC) obtained for isolated SAP and OCT parameters were compared with MLCs using OCT+SAP data. RESULTS: Combining OCT and SAP data, MLCs' aROCs varied from 0.777(CTREE) to 0.946 (RAN).The best OCT+SAP aROC obtained with RAN (0.946) was significantly larger the best single OCT parameter (p<0.05), but was not significantly different from the aROC obtained with the best single SAP parameter (p=0.19). CONCLUSION: Machine learning classifiers trained on OCT and SAP data can successfully discriminate between healthy and glaucomatous eyes. The combination of OCT and SAP measurements improved the diagnostic accuracy compared with OCT data alone.OBJETIVO: Avaliar a sensibilidade e especificidade dos classificadores de aprendizagem de máquina no diagnóstico de glaucoma usando Spectral Domain OCT (SD-OCT) e perimetria automatizada acromática (PAA). MÉTODOS: Estudo transversal observacional. Sessenta e dois pacientes com glaucoma e 48 indivíduos normais foram incluídos. Todos os pacientes foram submetidos a exame oftalmológico completo, e perimetria automatizada acromática (24-2 SITA; Humphrey Field Analyzer II, Carl Zeiss Meditec, Inc., Dublin, CA) e exame de imagem da camada de fibras nervosas utilizando SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec Inc., Dublin, California). Curvas ROC (Receiver operator characteristic) foram obtidas para todos os parâmetros do SD-OCT e índices globais do campo visual (MD, PSD, GHT). Subsequentemente, os seguintes classificadores de aprendizagem de máquina (CAMs) foram testados usando parâmetros do OCT e CV: Bagging (BAG), Naive-Bayes (NB), Multilayer Perceptron (MLP), Radial Basis Function (RBF), Random Forest (RAN), Ensemble Selection (ENS), Classification Tree (CTREE), Ada Boost M1(ADA), Support Vector Machine Linear (SVML) e Support Vector Machine Gaussian (SVMG). Áreas abaixo da curva ROC (aROC) obtidas com os parâmetros isolados do campo visual (CV) e OCT foram comparados com os CAMs usando dados associados do OCT e CV. RESULTADOS: Combinando os dados do OCT e do CV, aROCs dos CAMs variaram entre 0,777(CTREE) e 0,946 (RAN). A maior aROC dos CAMs OCT+CV obtida com RAN (0,946) foi significativamente maior que o melhor parâmetro do OCT (p<0,05), mas não houve diferença estatística significativa com o melhor parâmetro do CV (p=0,19). CONCLUSÃO: Os classificadores de aprendizagem de máquina treinados com dados do OCT e CV podem discriminar entre olhos normais e glaucomatosos com sucesso. A combinação das medidas do OCT e CV melhoraram a acurácia diagnóstica comparados aos parâmetros do OCT.17017

Analysis of an elevator system using discrete event simulation: case study

This paper documents the work conducted to simulate an elevator system, using SIMIO software. The modelled system represents a case study that was analyzed in a hospital at Braga, Portugal. A previ-ous work on the same case study concluded that the best dwell time configuration would be around 10 seconds, however it did not consider the impact of different client demand on the elevator system. In this sense, this paper analyses the impact of both parameters on the performance of the system. This will be achieved by analyzing the impact on the total time spent by clients in the system, the number of clients inside the system, and waiting for the elevator, waiting time, average elevator occupation and number of elevator movements. Conclusions and future work agenda were discussed in the conclusions section.This work has been supported by FCT -Fundacao para a Ciencia e Tecnologia in the scope of the project: PEstOE/EEI/UI0319/2014 (ALGORITMI)

Sensitivity And Specificity Of Machine Learning Classifiers For Glaucoma Diagnosis Using Spectral Domain Oct And Standard Automated Perimetry.

To evaluate the sensitivity and specificity of machine learning classifiers (MLCs) for glaucoma diagnosis using Spectral Domain OCT (SD-OCT) and standard automated perimetry (SAP). Observational cross-sectional study. Sixty two glaucoma patients and 48 healthy individuals were included. All patients underwent a complete ophthalmologic examination, achromatic standard automated perimetry (SAP) and retinal nerve fiber layer (RNFL) imaging with SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec Inc., Dublin, California). Receiver operating characteristic (ROC) curves were obtained for all SD-OCT parameters and global indices of SAP. Subsequently, the following MLCs were tested using parameters from the SD-OCT and SAP: Bagging (BAG), Naive-Bayes (NB), Multilayer Perceptron (MLP), Radial Basis Function (RBF), Random Forest (RAN), Ensemble Selection (ENS), Classification Tree (CTREE), Ada Boost M1(ADA),Support Vector Machine Linear (SVML) and Support Vector Machine Gaussian (SVMG). Areas under the receiver operating characteristic curves (aROC) obtained for isolated SAP and OCT parameters were compared with MLCs using OCT+SAP data. Combining OCT and SAP data, MLCs' aROCs varied from 0.777(CTREE) to 0.946 (RAN).The best OCT+SAP aROC obtained with RAN (0.946) was significantly larger the best single OCT parameter (p<0.05), but was not significantly different from the aROC obtained with the best single SAP parameter (p=0.19). Machine learning classifiers trained on OCT and SAP data can successfully discriminate between healthy and glaucomatous eyes. The combination of OCT and SAP measurements improved the diagnostic accuracy compared with OCT data alone.76170-

On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

In this report, a successful thermodynamical model was employed to understand the structural transition in Er$_5$Si$_4$, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a $\Delta F_0 = -$0.262 eV. Finally, it was achieved a variation of Seebeck coefficient ($\sim$ 6 $\mu$V) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

Evaluation of two ultrasonic systems for analysis of porosity in ceramic

The Ultrasound Laboratory of the Nuclear Engineering Institute (LABUS / IEN) has developed an ultrasonic technique to measure porosity in nuclear fuel pellets (UO2). By difficulties related to the handling of UO2 pellets, Alumina (Al2O3) pellets have been used in preliminary tests, until a methodology for tests with pellets of UO2 could be defined. In a previous work, in which a contact ultrasonic technique was used, good results were obtained to measure the porosity of Alumina pellets. In the current studies, it was found that the frequency spectrum of an ultrasonic pulse is very sensitive to the porosity of the medium in which it propagates. In order to define the most appropriate experimental apparatus for using immersion technique in future tests, two ultrasonic systems, available in LABUS, which permit to work with the ultrasonic pulse in the frequency domain were evaluated . One system was the Explorer II (Matec INSTRUMENTS) and the other the ultrasonic pulse generator Epoch 4 Plus (Panametrics) coupled with an oscilloscope TDS 3032B (Tektronix). For this evaluation, several frequency spectra were obtained with the two equipment, by the passage of the ultrasonic wave in the same pellet of Alumina. This procedure was performed on four different days, on each day 12 ultrasonic signals were acquired, one signal every 10 minutes, with each apparatus. The results were compared and analyzed as regard the repeatability of the frequency spectra obtained

Observações do não-observável: breve relato sobre o I Encontro “Ayahuasca e o Tratamento da Dependência”

“Dá pra se livrar do vício em drogas usando outra? Como é que uma substância alucinógena pode tratar da dependência? Ayahuasca é droga? E o usuário em drogas ou álcool pode ficar viciado em ayahuasca? Como é esse tratamento? Ele funciona mesmo?” Essas são apenas algumas das perguntas que surgem imediatamente ao abordar essa temática. O I Encontro “Ayahuasca e o Tratamento da Dependência”[2], evento realizado entre os dias 12 e 14 de setembro de 2011, no Anfiteatro da Geografia da Universidade..