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A Biblioteca Digital da Produção Intelectual e Científica da Unicamp tem por objetivo reunir e disseminar a produção intelectual, acadêmica e cultural da universidade e preservar sua memória institucional, além de contribuir para ampliar a visibilidade da instituição e dos seus pesquisadores em âmbito nacional e internacional.

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‣ Depletion study and estimation of the withdrawal period for oxytetracycline in tilapia cultured in Brazil

Paschoal, J. A. R.; Bicudo, A. J. A.; Cyrino, J. E. P.; Reyes, F. G. R.; Rath, S.
Fonte: Wiley-Blackwell; Malden Publicador: Wiley-Blackwell; Malden
Tipo: Artigo de Revista Científica
Português
Defining pharmacokinetic parameters and depletion intervals for antimicrobials used in fish represents important guidelines for future regulation by Brazilian agencies of the use of these substances in fish farming. This article presents a depletion study for oxytetracycline (OTC) in tilapias (Orechromis niloticus) farmed under tropical conditions during the winter season. High performance liquid chromatography, with fluorescence detection for the quantitation of OTC in tilapia fillets and medicated feed, was developed and validated. The depletion study with fish was carried out under monitored environmental conditions. OTC was administered in the feed for five consecutive days at daily dosages of 80 mg/kg body weight. Groups of ten fish were slaughtered at 1, 2, 3, 4, 5, 8, 10, 15, 20, and 25 days after medication. After the 8th day posttreatment, OTC concentrations in the tilapia fillets were below the limit of quantitation (13 ng/g) of the method. Linear regression of the mathematical model of data analysis presented a coefficient of 0.9962. The elimination half- life for OTC in tilapia fillet and the withdrawal period were 1.65 and 6 days, respectively, considering a percentile of 99% with 95% of confidence and a maximum residue limit of 100 ng/g. Even though the study was carried out in the winter under practical conditions where water temperature varied...

‣ Orality Disorders in Melancholia: Acedia as Stagnation

Magtaz, Ana Cecilia; Berlinck, Manoel Tosta
Fonte: Assoc Univ Pequisa Psicopatologia Fundamental; Sao Paulo Publicador: Assoc Univ Pequisa Psicopatologia Fundamental; Sao Paulo
Tipo: Artigo de Revista Científica
Português
In this article valuable contributions by Lasegue, Freud and Abraham are discussed, as they are all indispensible to the understanding of orality disorders in melancholia. Although none of the above authors used the exact term "orality disorders," their understandings of both hysteria and melancholia are important in the debate surrounding the clinical treatment of these difficulties. Sadness is a common denominator for the authors, but contributions on acedia, the "noonday demon" mentioned by Agamben, are also important. Acedia is defined as stagnation, a desperate lack of vigor when faced with a wearying and demanding situation. Those who suffer from chronic acedia feel great inertia and are unable to envision a future. They see their creativity wane away, especially due to the painful isolation caused by what might be called anguished sadness - a denial of sadness through manic action.

‣ The Clinical Case as a Basis for Research in Fundamental Psychopathology

Magtaz, Ana Cecilia; Berlinck, Manoel Tosta
Fonte: Assoc Univ Pequisa Psicopatologia Fundamental; Sao Paulo Publicador: Assoc Univ Pequisa Psicopatologia Fundamental; Sao Paulo
Tipo: Artigo de Revista Científica
Português
(The Clinical Case as a Basis for Research in Fundamental Psychopathology) This article discusses aspects that hinder the process of drawing up clinical cases and stresses their importance for research in fundamental psychopathology. The author bases her thinking on several texts by Freud and his followers about the technique and the interpretation of dreams. In these texts, clinical cases are used to express a problem that must be investigated. The grounds for research follow the same logic as that used for interpreting dreams.

‣ Relationship between lower-limb muscle strength and frailty among elderly people

Batista, Fernanda Sotello; de Oliveira Gomes, Grace Angelica; Neri, Anita Liberalesso; Guariento, Maria Elena; Cintra, Fernanda Aparecida; Rosario de Sousa, Maria da Luz; D'Elboux, Maria Jose
Fonte: Associacao Paulista Medicina; Sao Paulo Publicador: Associacao Paulista Medicina; Sao Paulo
Tipo: Artigo de Revista Científica
Português
CONTEXT AND OBJECTIVE: Sarcopenia is the main factor involved in the development of frailty syndrome. The aims here were to investigate relationships between lower-limb muscle strength and the variables of sex, age and frailty criteria; compare lower-limb muscle strength with each frailty criterion; and assess the power of each criterion for estimating the risk of frailty among elderly outpatients. DESIGN AND SETTING: Cross-sectional study at the Geriatrics Outpatient Clinic of a university hospital in Campinas. METHOD: A non-probabilistic convenience sample of 150 elderly people of both sexes who were followed up as outpatients was assessed. Sociodemographic data (sex and age) and physical health data (frailty criteria and the five-times sit-to-stand test) were gathered. Descriptive, comparative and multivariate logistic regression analyses were performed. RESULTS: The majority of the elderly people (77.3%) were 70 years of age or over, with predominance of females (64.2%) and had a low score for the five-times sit-to-stand test (81.4% scored 0 or 1); 55.3% of the elderly people presented three or more frailty criteria. A significant association was found between lower-limb muscle strength and the variables of age and number of frailty criteria. CONCLUSIONS: Lower levels of lower-limb muscle strength were associated with advanced age and greater presence of signs of frailty. Moreover...

‣ CRITICAL POINTS OF THE PRODUCTION PROCESS OF SOLID WOOD FLOORING

Casemiro Soares, Philipe Ricardo; Milan, Marcos; Jankowsky, Ivaldo Pontes; da Silva Maciel, Antonio Jose; Kanieski, Maria Raquel
Fonte: Centro Pesquisas Florestais, Ufsm; Santa Maria Publicador: Centro Pesquisas Florestais, Ufsm; Santa Maria
Tipo: Artigo de Revista Científica
Português
The quality concepts represent one of the important factors for the success of organizations and among these concepts the stabilization of the production process contributes to the improvement, waste reduction and increased competitiveness. Thus, this study aimed to evaluate the production process of solid wood flooring on its predictability and capacity, based on its critical points. Therefore, the research was divided into three stages. The first one was the process mapping of the company and the elaboration of flowcharts for the activities. The second one was the identification and the evaluation of the critical points using FMEA (Failure Mode and Effect Analysis) adapted methodology. The third one was the evaluation of the critical points applying the statistical process control and the determination of the process capability for the C-pk index. The results showed the existence of six processes, two of them are critical. In those two ones, fifteen points were considered critical and two of them, related with the dimension of the pieces and defects caused by sandpaper, were selected for evaluation. The productive process of the company is unstable and not capable to produce wood flooring according to the specifications and, therefore these specifications should be reevaluated.

‣ CONTEXT TREE SELECTION AND LINGUISTIC RHYTHM RETRIEVAL FROM WRITTEN TEXTS

Galves, Antonio; Galves, Charlotte; Garcia, Jesus E.; Garcia, Nancy L.; Leonardi, Florencia
Fonte: Inst Mathematical Statistics; Cleveland Publicador: Inst Mathematical Statistics; Cleveland
Tipo: Artigo de Revista Científica
Português
The starting point of this article is the question "How to retrieve fingerprints of rhythm in written texts?" We address this problem in the case of Brazilian and European Portuguese. These two dialects of Modern Portuguese share the same lexicon and most of the sentences they produce are superficially identical. Yet they are conjectured, on linguistic grounds, to implement different rhythms. We show that this linguistic question can be formulated as a problem of model selection in the class of variable length Markov chains. To carry on this approach, we compare texts from European and Brazilian Portuguese. These texts are previously encoded according to some basic rhythmic features of the sentences which can be automatically retrieved. This is an entirely new approach from the linguistic point of view. Our statistical contribution is the introduction of the smallest maximizer criterion which is a constant free procedure for model selection. As a by-product, this provides a solution for the problem of optimal choice of the penalty constant when using the BIC to select a variable length Markov chain. Besides proving the consistency of the smallest maximizer criterion when the sample size diverges, we also make a simulation study comparing our approach with both the standard BIC selection and the Peres-Shields order estimation. Applied to the linguistic sample constituted for our case study...

‣ Landscape changes in Serra do Japi: legal protection or scientific expectation?

Hardt, Elisa; dos Santos, Rozely Ferreira; Lopes Pereira-Silva, Erico F.
Fonte: Univ Austral Chile, Fac Ciencias Forestales; Valdivia Publicador: Univ Austral Chile, Fac Ciencias Forestales; Valdivia
Tipo: Artigo de Revista Científica
Português
The creation of new legally protected areas brings many conflicts that distance the real landscape from the expected according to environmental law or conservation researchers. In this study, we mapped and compared the changes in Serra da Japi (Sao Paulo State, Brazil) throughout 40 years with scenarios of legal protection and scientific expectation on forest conservation, to evaluate the distance between them. This may allow us to infer the direction of historical changes and assist in the debate among decision makers. The results showed that most legal requirements on forest protection in the current landscape have been met. The 1960s was the period when the forest cover was closest to the desirable conservation stage. Although the Serra do Japi has maintained large areas of forests during the entire study period, human interference increased with the expansion of reforestation and urban areas, and access roads were identified as a primary potential driving forces of change. In addition, habitat loss was observed in the landscape, which can represent the first phase of a sequence of modifications detrimental to the environmental conservation of this protected area, including decision changes to land use. In conclusion, the changes evolved toward conservation expectations...

‣ Optimization of Large-Scale Hydrothermal System Operation

Zambon, Renato C.; Barros, Mario T. L.; Lopes, Joao Eduardo G.; Barbosa, Paulo S. F.; Francato, Alberto L.; Yeh, William W. -G.
Fonte: Asce-Amer Soc Civil Engineers; Reston Publicador: Asce-Amer Soc Civil Engineers; Reston
Tipo: Artigo de Revista Científica
Português
This paper presents the development of a mathematical model to optimize the management and operation of the Brazilian hydrothermal system. The system consists of a large set of individual hydropower plants and a set of aggregated thermal plants. The energy generated in the system is interconnected by a transmission network so it can be transmitted to centers of consumption throughout the country. The optimization model offered is capable of handling different types of constraints, such as interbasin water transfers, water supply for various purposes, and environmental requirements. Its overall objective is to produce energy to meet the country's demand at a minimum cost. Called HIDROTERM, the model integrates a database with basic hydrological and technical information to run the optimization model, and provides an interface to manage the input and output data. The optimization model uses the General Algebraic Modeling System (GAMS) package and can invoke different linear as well as nonlinear programming solvers. The optimization model was applied to the Brazilian hydrothermal system, one of the largest in the world. The system is divided into four subsystems with 127 active hydropower plants. Preliminary results under different scenarios of inflow...

‣ Wastewater treatment and reuse water production using sand filters

Tonetti, Adriano Luiz; Coraucci Filho, Bruno; Nicolau, Cintia Elena; Barbosa, Martina; Tonon, Daniele
Fonte: Assoc Brasileira Engenharia Sanitaria Ambiental; Rio de Janeiro Publicador: Assoc Brasileira Engenharia Sanitaria Ambiental; Rio de Janeiro
Tipo: Artigo de Revista Científica
Português
In this research it was studied a system composed by the anaerobic filter combined with a sand filter for the wastewater treatment. For this, three anaerobic filters were operated with hydraulic detention time of nine hours which had the effluent disposed over four sand filters in different frequencies of application. On the first sand filter, 50 L.m(-2) were applied once a day. On the second, the third and the fourth filters, the same load was disposed in twice, three and four times a day, distributed between 9 a. m. and 4 p. m. The system presented a final effluent suitable for the COD and BOD legislation maximum limit to be discharged into water body (Decreto Paulista no 8,468/1976), showing the viability of dispose a higher quantity of effluent then the one suggested by NBR 13969/1997, which guides the constructive aspects for this kind of treatment.

‣ Riverbed: A Novel User-Steered Image Segmentation Method Based on Optimum Boundary Tracking

Miranda, Paulo A. V.; Falcao, Alexandre Xavier; Spina, Thiago V.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway Publicador: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway
Tipo: Artigo de Revista Científica
Português
This paper presents an optimum user-steered boundary tracking approach for image segmentation, which simulates the behavior of water flowing through a riverbed. The riverbed approach was devised using the image foresting transform with a never-exploited connectivity function. We analyze its properties in the derived image graphs and discuss its theoretical relation with other popular methods such as live wire and graph cuts. Several experiments show that riverbed can significantly reduce the number of user interactions (anchor points), as compared to live wire for objects with complex shapes. This paper also includes a discussion about how to combine different methods in order to take advantage of their complementary strengths.

‣ MODEL PARTITIONS AND COMPACT TEST CASE SUITES

Bonifacio, Adilson Luiz; Moura, Arnaldo Vieira; Simao, Adenilso
Fonte: World Scientific Publ Co Pte Ltd; Singapore Publicador: World Scientific Publ Co Pte Ltd; Singapore
Tipo: Artigo de Revista Científica
Português
We present a generalized test case generation method, called the G method. Although inspired by the W method, the G method, in contrast, allows for test case suite generation even in the absence of characterization sets for the specification models. Instead, the G method relies on knowledge about the index of certain equivalences induced at the implementation models. We show that the W method can be derived from the G method as a particular case. Moreover, we discuss some naturally occurring infinite classes of FSM models over which the G method generates test suites that are exponentially more compact than those produced by the W method.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

‣ New Insights on Nontechnical Losses Characterization Through Evolutionary-Based Feature Selection

Oba Ramos, Caio Cesar; de Souza, Andre Nunes; Falcao, Alexandre Xavier; Papa, Joao Paulo
Fonte: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway Publicador: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway
Tipo: Artigo de Revista Científica
Português
Although nontechnical losses automatic identification has been massively studied, the problem of selecting the most representative features in order to boost the identification accuracy and to characterize possible illegal consumers has not attracted much attention in this context. In this paper, we focus on this problem by reviewing three evolutionary-based techniques for feature selection, and we also introduce one of them in this context. The results demonstrated that selecting the most representative features can improve a lot of the classification accuracy of possible frauds in datasets composed by industrial and commercial profiles.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

‣ Semi-Supervised Dimensionality Reduction based on Partial Least Squares for Visual Analysis of High Dimensional Data

Paiva, Jose Gustavo S.; Schwartz, William Robson; Pedrini, Helio; Minghim, Rosane
Fonte: Wiley-Blackwell; Hoboken Publicador: Wiley-Blackwell; Hoboken
Tipo: Artigo de Revista Científica
Português
Dimensionality reduction is employed for visual data analysis as a way to obtaining reduced spaces for high dimensional data or to mapping data directly into 2D or 3D spaces. Although techniques have evolved to improve data segregation on reduced or visual spaces, they have limited capabilities for adjusting the results according to user's knowledge. In this paper, we propose a novel approach to handling both dimensionality reduction and visualization of high dimensional data, taking into account user's input. It employs Partial Least Squares (PLS), a statistical tool to perform retrieval of latent spaces focusing on the discriminability of the data. The method employs a training set for building a highly precise model that can then be applied to a much larger data set very effectively. The reduced data set can be exhibited using various existing visualization techniques. The training data is important to code user's knowledge into the loop. However, this work also devises a strategy for calculating PLS reduced spaces when no training data is available. The approach produces increasingly precise visual mappings as the user feeds back his or her knowledge and is capable of working with small and unbalanced training sets.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

‣ Transthoracic Cardiac Ultrasonic Stimulation Induces a Negative Chronotropic Effect

Buiochi, Elaine Belassiano; Miller, Rita J.; Hartman, Emily; Buiochi, Flavio; Bassani, Rosana A.; Costa, Eduardo T.; O'Brien, William D., Jr.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway Publicador: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway
Tipo: Artigo de Revista Científica
Português
The objective of this study is to investigate cardiac bioeffects resulting from ultrasonic stimulation using a specific set of acoustical parameters. Ten Sprague-Dawley rats were anesthetized and exposed to 1-MHz ultrasound pulses of 3-MPa peak rarefactional pressure and approximately 1% duty factor. The pulse repetition frequency started slightly above the heart rate and was decreased by 1 Hz every 10 s, for a total exposure duration of 30 s. The control group was composed of five rats. Two-way analysis of variance for repeated measures and Bonferroni post hoc tests were used to compare heart rate and ejection fraction, which was used as an index of myocardial contractility. It was demonstrated for the first time that transthoracic ultrasound has the potential to decrease the heart rate by similar to 20%. The negative chronotropic effect lasted for at least 15 min after ultrasound exposure and there was no apparent gross damage to the cardiac tissue.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

‣ Introduction to the Software-defined Radio Approach

Selva, A. F. B.; Reis, A. L. G.; Lenzi, K. G.; Meloni, L. G. P.; Barbin, S. E.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway Publicador: IEEE-Inst Electrical Electronics Engineers Inc; Piscataway
Tipo: Artigo de Revista Científica
Português
Telecommunications have been in constant evolution during past decades. Among the technological innovations, the use of digital technologies is very relevant. Digital communication systems have proven their efficiency and brought a new element in the chain of signal transmitting and receiving, the digital processor. This device offers to new radio equipments the flexibility of a programmable system. Nowadays, the behavior of a communication system can be modified by simply changing its software. This gave rising to a new radio model called Software Defined Radio (or Software-Defined Radio - SDR). In this new model, one moves to the software the task to set radio behavior, leaving to hardware only the implementation of RF front-end. Thus, the radio is no longer static, defined by their circuits and becomes a dynamic element, which may change their operating characteristics, such as bandwidth, modulation, coding rate, even modified during runtime according to software configuration. This article aims to present the use of GNU Radio software, an open-source solution for SDR specific applications, as a tool for development configurable digital radio.

‣ CdSe/CdTe interface band gaps and band offsets calculated using spin-orbit and self-energy corrections

Ribeiro, M., Jr.; Ferreira, L. G.; Fonseca, L. R. C.; Ramprasad, R.
Fonte: Elsevier; Amsterdam Publicador: Elsevier; Amsterdam
Tipo: Artigo de Revista Científica
Português
We performed ab initio calculations of the electronic structures of bulk CdSe and CdTe, and their interface band alignments on the CdSe in-plane lattice parameters. For this, we employed the LDA-1/2 self-energy correction scheme [L.G. Ferreira, M. Marques, L.K. Teles, Phys. Rev. B 78 (2008) 125116] to obtain corrected band gaps and band offsets. Our calculations include the spin-orbit effects for the bulk cases, which have shown to be of importance for the equilibrium systems and are possibly degraded in these strained semiconductors. Therefore, the SO showed reduced importance for the band alignment of this particular system. Moreover, the electronic structure calculated along the transition region across the CdSe/CdTe interface shows an interesting non-monotonic variation of the band gap in the range 0.8-1.8 eV, which may enhance the absorption of light for corresponding frequencies at the interface between these two materials in photovoltaic applications. (C) 2012 Elsevier B.V. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

‣ Ab initio calculation of the CdSe/CdTe heterojunction band offset using the local-density approximation-1/2 technique with spin-orbit corrections

Ribeiro, M., Jr.; Fonseca, L. R. C.; Sadowski, T.; Ramprasad, R.
Fonte: Amer Inst Physics; Melville Publicador: Amer Inst Physics; Melville
Tipo: Artigo de Revista Científica
Português
We performed ab initio calculations of the electronic structures of bulk CdSe and CdTe and of their interface. We employed the local-density approximation-1/2 self-energy correction scheme [L. G. Ferreira, M. Marques, and L. K. Teles, Phys. Rev. B 78, 125116 (2008)] to obtain improved band gaps and band offsets, as well as spin-orbit coupling to further correct the valence band edges. Our results are in good agreement with experimental values for bulk band gaps and reproduce the staggered band alignment characteristic of this system. We found that the spin-orbit effect is of considerable importance for the bulk band gaps, but has little impact on the band offset of this particular system. Moreover, the electronic structure calculated along the 61.4 angstrom transition region across the CdSe/CdTe interface shows a non-monotonic variation of the bandgap in the range 0.8-1.8 eV. This finding may have important implications to the absorption of light along the interface between these two materials in photovoltaic applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3699054]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

‣ Medium Light and Medium Roast Paper-Filtered Coffee Increased Antioxidant Capacity in Healthy Volunteers: Results of a Randomized Trial

Faraldo Correa, Telma Angelina; Monteiro, Marcela Piedade; Nogueira Mendes, Thaise Maria; de Oliveira, Daniela Moura; Rogero, Marcelo Macedo; Benites, Cibelem Iribarrem; Christiano de Matos Vinagre, Carmen Guilherme; Mioto, Bruno Mahler; Tarasoutchi, Dani
Fonte: Springer; Dordrecht Publicador: Springer; Dordrecht
Tipo: Artigo de Revista Científica
Português
We compared the effects of medium light roast (MLR) and medium roast (MR) paper-filtered coffee on antioxidant capacity and lipid peroxidation in healthy volunteers. In a randomized crossover study, 20 volunteers consumed 482 +/- 61 ml/day of MLR or MR for four weeks. Plasma total antioxidant status (TAS), oxygen radical absorbance capacity (ORAC), oxidized LDL and 8-epi-prostaglandin F2 alpha, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity were measured at baseline and after the interventions. MLR had higher chlorogenic acids-(CGA; 334 mg/150 mL) and less caffeine (231 mg/150 ml) than MR had (210 and 244 mg/150 ml, respectively). MLR also had fewer Maillard reaction products (MRP) than MR had. Compared with baseline, subjects had an increase of 21 and 26 % in TAS, 13 and 13 % in CAT, 52 and 75 % in SOD, and 62 and 49 % in GPx after MLR and MR consumption (P < 0.001), respectively. ORAC increased after MLR (P = 0.004). No significant alteration in lipid peroxidation biomarkers was observed. Both coffees had antioxidant effects. Although MLR contained more CGA, there were similar antioxidant effects between the treatments. MRP may have contributed as an antioxidant. These effects may be important in protecting biological systems and reducing the risk of diseases related to oxidative stress.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

‣ Correlation of the Physicochemical and Structural Properties of pDNA/Cationic Liposome Complexes with Their in Vitro Transfection

Balbino, Tiago A.; Gasperini, Antonio A. M.; Oliveira, Cristiano L. P.; Azzoni, Adriano R.; Cavalcanti, Leide P.; de La Torre, Lucimara G.
Fonte: Amer Chemical Soc; Washington Publicador: Amer Chemical Soc; Washington
Tipo: Artigo de Revista Científica
Português
In this study, we characterized the conventional physicochemical properties of the complexes formed by plasmid DNA (pDNA) and cationic liposomes (CL) composed of egg phosphatidylcholine (EPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) (50/25/25% molar ratio). We found that these properties are nearly unaffected at the studied ranges when the molar charge ratio (R-+/-) between the positive charge from the CL and negative charge from pDNA is not close to the isoneutrality region (R-+/- = 1). However, the results from in vitro transfection of HeLa cells showed important differences when R-+/- is varied, indicating that the relationships between the physicochemical and biological characteristics were not completely elucidated. To obtain information regarding possible liposome structural modifications, small-angle X-ray scattering (SAXS) experiments were performed as a function of R-+/- to obtain correlations between structural, physicochemical, and transfection properties. The SAXS results revealed that pDNA/CL complexes can be described as being composed of single bilayers, double bilayers, and multiple bilayers, depending on the R-+/- value. Interestingly, for R-+/- = 9...

‣ Drosophila melanogaster S2 cells for expression of heterologous genes: From gene cloning to bioprocess development

Moraes, Angela M.; Jorge, Soraia A. C.; Astray, Renato M.; Suazo, Claudio A. T.; Calderon Riquelme, Camilo E.; Augusto, Elisabeth F. P.; Tonso, Aldo; Pamboukian, Marilena M.; Piccoli, Rosane A. M.; Barral, Manuel F.; Pereira, Carlos A.
Fonte: Pergamon-Elsevier Science Ltd; Oxford Publicador: Pergamon-Elsevier Science Ltd; Oxford
Tipo: Artigo de Revista Científica
Português
In the present review we discuss strategies that have been used for heterologous gene expression in Drosophila melanogaster Schneider 2 (S2) cells using plasmid vectors. Since the growth of S2 cells is not dependent on anchorage to solid substrates, these cells can be easily cultured in suspension in large volumes. The factors that most affect the growth and gene expression of S2 cells, namely cell line, cell passage, inoculum concentration, culture medium, temperature, dissolved oxygen concentration, pH, hydrodynamic forces and toxic metabolites, are discussed by comparison with other insect and mammalian cells. Gene expression, cell metabolism, culture medium formulation and parameters involved in cellular respiration are particularly emphasized. The experience of the authors with the successful expression of a biologically functional protein, the rabies virus glycoprotein (RVGP), by recombinant S2 cells is presented in the topics covered. (C) 2011 Elsevier Inc. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)