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Coating independent cytotoxicity of citrate-and PEG-coated silver nanoparticles on a human hepatoma cell line

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Journal of Environmental Sciences 2017年第1期29卷 191-201页

作者： Veronica Bastos jose M.P.Ferreira-de-Oliveira Joana Carrola Ana L.Daniel-da-Silva Iola F.Duarte conceicao Santos Helena Oliveira CESAM&Laboratory of Biotechnology and Cytomics Department of BiologyUniversity of Aveiro3810-193 AveiroPortugal CICECO-Aveiro Institute of Materials Department of ChemistryUniversity of Aveiro3810-193 AveiroPortugal Department of Biology Faculty of SciencesUniversity of Porto4169-007 PortoPortugal

The antibacterial potential of silver nanoparticles（AgNPs） resulted in their increasing incorporation into consumer,industrial and biomedical ***,human and environmental exposure to AgNPs（either as an engineered product or a contaminant）supports the emergent research on the features conferring them different toxicity *** this study,30 ran AgNPs coated with citrate or poly（ethylene glycol）（PEG） were used to assess the influence of coating on the effects produced on a human hepatoma cell line（HepG2）,namely in terms of viability,apoptosis,apoptotic related genes,cell cycle and cyclins gene *** types of coated AgNPs decreased cell proliferation and viability with a similar toxicity *** the concentrations used（11 and 5 μg/mL corresponding to IC50 and-IC10 levels,respectively） the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2（anti-apoptotic gene）and BAX（pro-apoptotic gene） were both ***,both AgNPs affected HepG2 cell cycle progression at the higher concentration（11 μg/mL） by increasing the percentage of cells in S（synthesis phase） and G2（Gap 2 phase） *** the cell-cycle related genes,the expression of cyclin B1 and cyclin E1 genes were ***,this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression,cell cycle dynamics and cyclin regulation in a similar *** research is needed to determine the properties that confer AgNPs at lower toxicity,since their use has proved helpful in several industrial and biomedical contexts.

关键词： Silver nanoparticles(AgNPs) Citrate Polyethylene glycol)(PEG) HepG2 cells Cytotoxicity Nanotoxicology

Characteristics of the CsI:Tl Scintillator Crystal for X-Ray Imaging Applications

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Materials Sciences and Applications 2018年第2期9卷 268-280页

作者： Maria da conceicao Costa Pereira Tufic Madi Filho jose Roberto Berretta Carlos Henrique de Mesquita Nuclear and Energy Research Institute—IPEN/CNEN-SP Sao PauloBrazil

Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10-3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.

关键词： Crystal Growth Scintillator X-Ray Imaging Systems Photodiodes Coupled Charge Device

Spatial and Temporal Quality of Water in the Itupararanga Reservoir,Alto Sorocaba Basin(SP),Brazil

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Journal of Water Resource and Protection 2013年第1期5卷 64-71页

作者： Felipe jose de Moraes Pedrazzi Fabiano Tomazini da conceicao Diego de Souza Sardinha Viviane Moschini-Carlos Marcelo Pompeo UNESP Universidade Estadual PaulistaRio ClaroBrazil ICT UNIFALPocos de CaldasBrazil UNESP Universidade Estadual PaulistaSorocabaBrazil IB USPSao PauloBrazil

Considering the great importance of the Itupararanga Reservoir, Upper Alto Sorocaba basin/SP, this study aimed to report the variations of some parameters of water quality in the spatial and temporal gradients in this multipurpose reservoir. The eutrophication of this reservoir was checked using the Carlson Index Modified and the results indicate that the surface water were classified as eutrophic and mesotrophic in wet and dry periods, being characterized the better quality of water in wet period. In the vertical gradient the results showed a stratiphication in all parameters analyzed, except for the electrical conductivity, with good correlation between total phosphorous and chlorophyll-a, indicating that eutrophication of the reservoir changes the conditions of algal growth, mainly in its initial area. Immediate interventions are needed, which must be directed to planning of land use, domestic effluents treatment, taking to an integrated management of this important watershed located in the Sao Paulo State.

关键词： Itupararanga Reservoir Limnology Eutrophication Environmental Management

Analysis of the Performance of Optical Code-Division Multiple-Access System(OCDMA),Operating with Gold Codes under Nonlinear Effects

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Journal of Electromagnetic Analysis and Applications 2013年第2期5卷 49-57页

作者： Glendo de Freitas Guimaraes Agliberto Melo Bastos Alisson da conceicao Ferreira Alex Sander Barros Queiroz jose Wally Mendonca Menezes jose Rubens Rodrigues de Sousa Antonio Sergio Bezerra Sombra Laboratorio de Telecomunicacoes e Ciencia e Engenharia dos Materiais(LOCEM) Departamento de FisicaUniversidade Federal do Ceara(UFC)FortalezaBrazil Laboratorio Especializado em Sistema de Telecomunicacoes e Ensino(LESTE) Departamento de TelematicaInstituto Federal do Ceara(IFCE)Campus FortalezaFortalezaBrazil Grupo de Fisica Aplicada e Docencia(GFAD) Instituto Federal do Ceara(IFCE)Campus SobralSobralBrazil Departamento de Engenharia de Teleinformatica(DETI) Centro de TecnologiaUniversidade Federal do Ceara(UFC)FortalezaBrazil Departamento de Engenharia de Energias Universidade da Integracao Internacional da Lusofonia Afro-Brasileira(UNILAB)RedencaoBrazil

A numerical simulation study of the performance of encoding and decoding of short optical pulse in OCDMA (Optical Code Division Multiple Access) systems under non-linear optical effects is presented. The performance of encoding and decoding short pulses is obtained through use of device FBG (fiber Bragg grating) where the codes are inserted through discrete jumps in the optical phase (±π). The multiuser interference is also the object of the present study, where a figure of merit (interference figure) is used to quantify the interference in multiuser auto and cross correlation. We evaluate the dependence of the multiuser interference for the coupling constant of FBG. Finally, the interference inserted in the autocorrelation due to nonlinear effects generated in the nonlinear switching of the coded pulse in a dual core nonlinear directional coupler is examined, where temporal broadening of pulses decoded is observed.

关键词： Fiber Bragg Grating Gold Code OCDMA All-Optical Digital Processing of Signals

MicroRNAs expression dynamics reveal post-transcriptional mechanisms regulating seed development in Phaseolus vulgaris L.

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Horticulture Research 2021年第1期8卷 195-211页

作者： jose Ricardo Parreira Michela Cappuccio Alma Balestrazzi Pedro Fevereiro Susana de Sousa Araujo Instituto de Tecnologia Quimica e Biologica Antonio Xavier Universidade Nova de LisboaAvenida da Republica2780-157 OeirasPortugal Department of Biology and Biotechnology“L.Spallanzani” University of Paviavia Ferrata 927100 PaviaItaly InnovPlantProtect Collaborative Laboratory Estrada de Gil Vaz7351-901 ElvasPortugal Present address:Association BLC3-Technology and Innovation Campus Centre Bio R&D UnitRua Nossa Senhora da Conceicao 2Lagares da Beira3405-155 Oliveira do HospitalPortugal

The knowledge on post-transcriptional regulation mechanisms implicated in seed development(SD)is still limited,particularly in one of the most consumed grain legumes,Phaseolus vulgaris *** explore for the first time the miRNA expression dynamics in *** developing ***-two known and 39 new miRNAs were found expressed in *** developing *** of the miRNAs identified were more abundant at 10 and 40 days after anthesis,suggesting that late embryogenesis/early filling and desiccation were SD stages in which miRNA action is more *** analysis and target prediction identified targets for 77 expressed *** several known miRNAs were predicted to target HD-ZIP,ARF,SPL,and NF-Y transcription factors families,most of the predicted targets for new miRNAs encode for functional ***-targets expression profiles evidenced that these miRNAs could tune distinct seed developmental *** more accumulated at early SD stages were implicated in regulating the end of embryogenesis,postponing the seed maturation program,storage compound synthesis and *** more accumulated at late SD stages could be implicated in seed quiescence,desiccation tolerance,and longevity with still uncovered roles in *** miRNAs herein described represent novel *** resources with potential application in future biotechnological approaches to modulate the expression of genes implicated in legume seed traits with impact in horticultural production systems.

关键词： mechanisms dynamics regulating