Colocando as mãos (e o conhecimento) na massa: uso de massa de modelar como atividade lúdica no ensino de Biologia Celular

Anais do 3° Encontro Nacional de Jogos e Atividades Lúdicas no Ensino de Química, Física e Biologia (Jalequim - Level III) - Núcleo de Desenvolvimento de Pesquisas em Ensino de Química/Ciências da UNILA (NuDDEQ)Nos últimos anos tem crescido as discussões de educadores e pesquisadores, sobre a busca por novos métodos e propostas de ensino. Para Santos et al. (2011) o aumento desses métodos e pesquisas visam superar o modelo tradicional de ensino, buscando o diálogo entre professores e educandos e a participação dos mesmos em sala de aul

Development and characterization of a nanomultilayer coating of pectin and chitosan : evaluation of its gas barrier properties and application on 'Tommy Atkins' mangoes

A nanomultilayer coating made of food-grade, bio-based materials (consisting of five nanolayers of pectin and chitosan) was produced. This coating was firstly characterized in terms of the water vapor, oxygen and carbon dioxide permeabilities; these parameters exhibited values of 0.019 ± 0.005 × 10−11, 0.069 ± 0.066 × 10−14 and 44.8 ± 32 × 10−14 g m/(Pa s m2), respectively, and are of the same order of magnitude of those found in other nanomultilayer systems. The nanomultilayer system was applied on whole ‘Tommy Atkins’ mangoes and the layers’ adsorption was confirmed by changes in the contact angle of the coated fruits’ skin. After 45 d of storage, uncoated mangoes presented a higher mass loss, higher total soluble solids and lower titratable acidity in comparison with coated mangoes. Uncoated mangoes had also a damaged and wrinkled appearance, showing evidence of microbial spoilage, and the flesh exhibited a slightly brownish color, in comparison with the coated mangoes. These results suggest a positive effect of the coating on gas flow reduction and on the consequent extension of the shelf-life of mangoes.The author Bartolomeu G.S. Medeiros was recipient of a scholarship from de Project Isac (Isac Mundus Cooperation, European Union) and is also a recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (Capes, Brazil). The author Ana C. Pinheiro is recipient of a fellowship (SFRH/BD/48120/2008) from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal). The present work was supported by CAPES/PROCAD/NF/1415/2007

Polysaccharide/protein nanomultilayer coatings: construction, characterization and evaluation of their effect on 'Rocha' pear (Pyrus communis L.) shelf-life

Nanolayered coatings of κ-carrageenan, a polysaccharide with good gas barrier properties, and lysozyme, a protein with antimicrobial action, were in a first stage assembled on aminolysed/charged polyethylene terephthalate (PET) pieces, which acted as a support, by alternate five-layer deposition. This was performed to allow the characterization of the nanomultilayer system. PET aminolysis was confirmed by Fourier transform infrared spectroscopy and contact angle, and the subsequent layer adsorption on aminolysed PET surface was confirmed by absorbance, contact angle and SEM images. The water vapour permeability and the oxygen permeability (O2P) of the five layers were found to be 0.013 ± 0.003 × 10−11 and 0.1 ± 0.01 × 10−14 g m−1 s−1 Pa−1, respectively. The nanomultilayer system was subsequently applied (without PET support) directly on ‘Rocha’ (Pyrus communis L.) fresh-cut pears and whole pears. Uncoated fresh-cut pears and whole pears presented higher mass loss, higher total soluble solids (TSS) and lower titratable acidity when compared with coated fresh-cut pears and whole pears. Uncoated fresh-cut pears also presented a darker colour. These results showed that the nanolayered coating assembled on the fruits’ surface has a positive effect on fruit quality and contributed to extend the shelf-life.Author Bartolomeu G. de S. Medeiros was a recipient of a scholarship from the project Isac (Isac Mundus Cooperation, European Union) and is also a recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (Capes, Brazil). Author A. C. Pinheiro is recipient of a fellowship (SFRH/BD/48120/2008) from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal)

Development and characterization of lactoferrin-GMP nanohydrogels : evaluation of pH, ionic strength and temperature effect

Lactoferrin (Lf) and glycomacropeptide (GMP), two bioactive proteins from milk, were used to produce nanohydrogels by electrostatic interaction and thermal gelation. Parameters such as protein concentration, molar ratio, pH, temperature and heating time were evaluated in order to develop the nanohydrogels, which were characterized in terms of morphology (Transmission Electron Microscopy TEM, Dynamic Light Scattering DLS, Atomic Force Microscopy AFM and Confocal Laser Scanning Microscopy CLSM) and stability. The aggregation of the mixture between Lf and GMP increased with the increase of temperature, resulting in particles with lower hydrodynamic diameter and polydispersity index (PdI). Nanohydrogels were obtained from the mixture of Lf and GMP solutions (0.02% (w/w) in molar ratio 1:7) at pH 5.0, and subsequently stirred and heated at 80 °C, during 20 min. Results showed that nanohydrogels have a spherical shape with a hydrodynamic diameter around 170 nm, a PdI of 0.1 and a swelling ratio of 30. The minimum size of nanohydrogels depends on protein concentration and molar ratio. Decreasing the protein concentrations and increasing the content of GMP molecules in solution, the hydrodynamic diameter and PdI of nanohydrogels decreased. The electrical charge values of nanohydrogels at different pH values suggest that Lf molecules are in the surface and GMP molecules are mostly in the core of the structure (confirmed by confocal microscopy). Also, it was observed that nanohydrogels' hydrodynamic diameter and PdI, after formation, are influenced when submitted at different conditions of pH, ionic strength and temperature. Lf-GMP nanohydrogels showed properties that indicate that they are a promising delivery system for food and pharmaceutical applications.The authors Ana I. Bourbon, Ana C. Pinheiro, Ricardo N. Pereira and Miguel A. Cerqueira are recipient of fellowships from the Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal) through grants SFRH/BD/73178/2010, SFRH/BD/48120/2008, SFRH/BPD/81887/2011 and SFRH/BPD/72753/2010, respectively. Maria G. Carneiro-da-Cunha express is gratitude to the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grant. The authors would like to acknowledge to Jorge Padrao from Centre of Biological Engineering, University of Minho and Andre Coelho from Federal University of Ceara for helping in electrophoresis measurements and to Rui Fernandes from IBMC, University of Porto for assistance in taking the TEM pictures. Also, the authors thank the FCT Strategic Projects PEst-OE/EQB/LA0023/2013 and PEst-C/EQB/LA0006/2013 (FCT and FEDER funds through COMPETE). The work also received financial support from the European Union (FEDER funds) under the framework of QREN (Programa Operacional Regional do Norte (ON.2 - O Novo Norte; FEDER) through projects NORTE-07-0124-FEDER-000028 and NORTE-07-0124-FEDER-000069

Cytogenetic analysis of Rhinella jimi (Stevaux, 2002) (Anura, Bufonidae) from northeastern Brazil

In this work we analyzed the karyotype of Rhinella jimi (Stevaux, 2002) (Anura, Bufonidae) from Picos (Piauí) in Northeastern Brazil. The chromosomes were examined using classical cytogenetic approaches (Giemsa, C-banding, and Ag-NOR staining). This species has 2n = 22 chromosomes, all metacentric or submetacentric. Heterochromatic segments were visualized at the centromeric region and the nucleolus organizer regions (NOR) were restricted to terminal regions of the short arms in pair 7. There was no evidence of heteromorphic sex chromosomes. The chromosomal analysis of R. jimi allowed us to identify a karyotype that is similar to many other species of Rhinella, in which the diploid number remains unchanged and without evidences of structural rearrangements.Asociación Herpetológica Argentin

Physical characterisation of an alginate/lysozyme nano-laminate coating and its evaluation on ‘coalho’ cheese shelf life

This work aimed at the characterisation of a nanolaminate coating produced by the layer-by-layer methodology and its evaluation on the preservation of ‘Coalho’ cheese. Initially, five alternate layers of alginate and lysozyme were assembled in an aminolysed/charged polyethylene terephthalate (A/C PET) and physically characterised by UV/VIS spectroscopy, contact angle, water vapour (WVTR) and oxygen (OTR) transmission rates and scanning electron microscopy. Afterwards, the same methodology was used to apply the nano-laminate coating in ‘Coalho’ cheese and its shelf life was evaluated during 20 days in terms of mass loss, pH, lipid peroxidation, titratable acidity and microbial count. UV/VIS spectroscopy and contact angle analyses confirmed the layers’ deposition and the successful assembly of nano-laminate coating on A/C PET surface. The coating presented WVTR and OTR values of 1.03×10−3 and 1.28× 10−4 g m−2 s−1, respectively. After 20 days, coated cheese showed lower values of mass loss, pH, lipidic peroxidation, microorganisms’ proliferation and higher titratable acidity in comparison with uncoated cheese. These results suggest that gas barrier and antibacterial properties of alginate/lysozyme nanocoating can be used to extend the shelf life of ‘Coalho’ cheese.The author Bartolomeu G. de S. Medeiros is recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES-Brazil). The author Marthyna P. Souza is recipient of a scholarship from Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) and was recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil). The authors Ana C. Pinheiro, Ana I. Bourbon and Miguel A. Cerqueira are recipients of a fellowship (SFRH/BD/48120/2008, SFRH/BD/73178/2010 and SFRH/BPD/72753/2010, respectively), supported by Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal). Maria G. Carneiro-da-Cunha express is gratitude to the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grant. The present work was supported by CAPES/PROCAD/NF/1415/2007. The support of EU Cost Action FA0904 is gratefully acknowledged

How useful is the assessment of lymphatic vascular density in oral carcinoma prognosis?

Abstract Background Lymphatic vessels are major routes for metastasis in head and neck squamous cell carcinoma (HNSCC), but lymphatic endothelial cells (LECs) are difficult to recognize in tumor histological sections. D2-40 stains podoplanin, a molecule expressed in LECs, however, the potential prognostic usefulness of this molecule is not completely understood in HNSCC. We aimed to investigate the value of assessing peritumoral and intratumoral lymphatic vessel density (LVD) as prognostic marker for HNSCC. Methods Thirty-one cases of HNSCC were stained for D2-40 and CD31. LVD and blood vessel density (BVD) were assessed by counting positive reactions in 10 hotspot areas at ×200 magnification. Results D2-40 was specific for lymphatic vessels and did not stain blood vascular endothelial cells. LECs showed more tortuous and disorganized structure in intratumoral lymphatic vessels than in peritumoral ones. No statistical differences were observed between peritumoral-LVD and intratumoral-LVD or between peritumoral-BVD and intratumoral-BVD. Tumor D2-40 staining was positively associated with lymphatic vessel invasion (p = 0.011). Conclusion LVD is a powerful marker for HNSCC prognosis. We found significant differences in peritumoral and intratumoral D2-40 immunoreactivity, which could have important implications in future therapeutic strategies and outcome evaluation