972 resultados para 6K-955-CB


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Objective. To determine the effects of different aging methods on the degradation and flexural strength of yttria-stabilized tetragonal zirconia (Y-TZP)Methods. Sixty disc-shaped specimens (0, 12 mm; thickness, 1.6 mm) of zirconia (Vita InCeram 2000 YZ Cubes, VITA Zahnfabrik) were prepared (ISO 6872) and randomly divided into five groups, according to the aging procedures (n=10): (C) control; (M) mechanical cycling (15,000,000 cycles/3.8 Hz/200N); (T) thermal cycling (6,000 cycles/5-55 degrees C/30 s); (TM) thermomechanical cycling (1,200,000 cycles/3.8 Hz/200N with temperature range from 5 C to 55 C for 60s each); (AUT) 12h in autoclave at 134 degrees C/2 bars; and (STO) storage in distilled water (37 degrees C/400 days). After the aging procedures, the monoclinic phase percentages were evaluated by X-ray diffraction (XRD), and topographic surface analysis was performed by 3D profilometry. The specimens were then subjected to biaxial flexure testing (1 mm/min, load 100 kgf, in water). The biaxial flexural strength data (MPa) were analyzed by 1-way ANOVA and Tukey's test (alpha = 0.05). The data for monoclinic phase percentage and profilometry (Ra) were analyzed by Kruskal-Wallis and Dunn's tests.Results. ANOVA revealed that flexural strength was affected by the aging procedures (p = 0.002). The M (781.6 MPa) and TM (771.3 MPa) groups presented lower values of flexural strength than did C (955 MPa), AUT (955.8 MPa), T (960.8 MPa) and STO (910.4 MPa). The monoclinic phase percentage was significantly higher only for STO (12.22%) and AUT (29.97%) when compared with that of the control group (Kruskal-Wallis test, p = 0.004). In addition, the surface roughnesses were similar among the groups (p = 0.165).Signcance. Water storage for 400 days and autoclave aging procedures induced higher phase transformation from tetragonal to monoclinic; however, they did not affect the flexural strength of Y-TZP ceramic, which decreased only after mechanical and thermomechanical cycling. (C) 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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The aim of this study was to investigate the electroencephalographic (EEG) response of equidae to a castration stimulus. Study 1 included 11 mules (2 1/2-8 years; 230-315 kg) and 11 horses (1 1/2-3 1/2 years; 315-480 kg); study 2 included four ponies (15-17 months; 176-229 kg). They were castrated under halothane anesthesia after acepromazine premedication (IV [study 1] and intramuscular [study 2]) and thiopental anesthetic induction. Animals were castrated using a semiclosed technique (study 1) and a closed technique (study 2). Raw EEG data were analyzed and the EEG variables, median frequency (F50), total power (Ptot), and spectral edge frequency (F95), were derived using standard techniques at skin incision (skin) and emasculation (emasc) time points. Baseline values of F50, Ptot, and F95 for each animal were used to calculate percentage change from baseline at skin incision and emasculation. Differences were observed in Ptot and F50 data between hemispheres in horses but not mules (study 1) and in one pony (study 2). A response to castration (>10% change relative to baseline) was observed in eight horses (73% of animals) and four mules (36% of animals) for F50 and nine horses (82%) and four mules (36%) for Ptot. No changes in F95 data were observed in any animal in study 1. Responses to castration were observed in three ponies (75% of animals) for F50, one pony (25%) for F95, and all ponies for Ptot Alteration of acepromazine administration and castration technique produced a protocol that identified changes in EEG frequency and power in response to castration. (c) 2014 Elsevier Inc. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The aim was to study the recovery of degraded pasture with the introduction of Stylosanthes macrocephala e capitata cv. Campo Grande on Brachiaria decumbens cv. Basilisk evaluating the levels N-total in roots, biomass, area, and length, diameter and root levels of macro and micronutrients in the soil. The experiment was conducted in the municipality of Andradina, Sao Paulo State, Brazil. The experimental design was a randomized block design in a split-plot (with and without phosphorus), with four replicates, forming the following treatments: control Brachiaria decumbens (CB), partial desiccation with 1.5 L ha(-1) of glyphosate (DP), total desiccation with 3.0 L ha(-1) of glyphosate (TD); tillage (T), soil scarification (S); harrowing rome (H) and plowing + disking (PD). Treatments H and PD were sown by broadcasting and the other in the form of direct seeding. Recovery strategies of grazing signal grass showed significant differences between treatments only for the content of N-total, there were no differences in geometric characteristics of roots and root biomass. The contents of macro and micronutrients in the soil showed no significant differences between the strategies of recovery. Fertilization had a significant effect for P. The introduction of estilosantes Campo Grande accompanied by techniques such as drying and plowing + disking contributed to increases in the N-total levels in the root system. Forms of introduction of legumes did not change the soil chemical properties.

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Biological processes are complex and possess emergent properties that can not be explained or predict by reductionism methods. To overcome the limitations of reductionism, researchers have been used a group of methods known as systems biology, a new interdisciplinary eld of study aiming to understand the non-linear interactions among components embedded in biological processes. These interactions can be represented by a mathematical object called graph or network, where the elements are represented by nodes and the interactions by edges that link pair of nodes. The networks can be classi- ed according to their topologies: if node degrees follow a Poisson distribution in a given network, i.e. most nodes have approximately the same number of links, this is a random network; if node degrees follow a power-law distribution in a given network, i.e. small number of high-degree nodes and high number of low-degree nodes, this is a scale-free network. Moreover, networks can be classi ed as hierarchical or non-hierarchical. In this study, we analised Escherichia coli and Saccharomyces cerevisiae integrated molecular networks, which have protein-protein interaction, metabolic and transcriptional regulation interactions. By using computational methods, such as MathematicaR , and data collected from public databases, we calculated four topological parameters: the degree distribution P(k), the clustering coe cient C(k), the closeness centrality CC(k) and the betweenness centrality CB(k). P(k) is a function that calculates the total number of nodes with k degree connection and is used to classify the network as random or scale-free. C(k) shows if a network is hierarchical, i.e. if the clusterization coe cient depends on node degree. CC(k) is an indicator of how much a node it is in the lesse way among others some nodes of the network and the CB(k) is a pointer of how a particular node is among several ...(Complete abstract click electronic access below)

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The main objective of this study was to analyze the behavior of variables related to swim ability at and above maximal lactate steady state (MLSS), performed at continuous and intermittent conditions in individuals with different aerobic performance levels. Participated of this study male swimmers with ages between 20 to 25 years, specialists in events of 400 m, 800 m and 1500 m and open water swims, with at least 3 years of experience in the modality. The individuals performed a maximal 400-m swim test. After this test, they were divided into two groups, in accordance with the speed attained during 400-m swim test: G1 (higher performance) and G2 (lower performance). For the determination of continuous MLSS (MLSSc), 2 to 4 trials of 30-min were performed. For the determination of the intermittent MLSS (MLSSi) 2 to 4 trials of 30-min (12 repetitions of 2 min 30 s, with 30 s of rest) were performed, in constant speed, with the first trial performed at 102.5% MLSSc. Th technical indexes, stroke rate (FB) and stroke length (CB) were determined in all tests. The SR was calculated trough recordings using the time needed to perform five stroke cycles. The SL was calculated dividing the speed by the SR. There was no significant difference on the antropometric characteristics between groups. The speed at and above MLSSc were significantly higher at G1 (1,23±0,05 e 1,27±0,06, respectively) than G2 (1,10±0,06 e 1,13±0,06, respectively). There was significant change in SL and SR in G2. In the same way, there was significant change in SL and SR only in G2, above MLSSc. Similar to continuous condition, the speeds at and above MLSSi were significantly higher in G1 (1,27±0,05 e 1,30±0,05, respectively) do que no G2 (1,14±0,07 e 1,16±0,07, respectively). There was significant change in SL and SR only in G2. There was significant change in SR and SL in both groups above MLSSi. Thus,...(Complete abstract click electronic access below)

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Nos últimos anos, a biotecnologia tem proporcionado avanços no desenvolvimento de biomateriais a serem utilizados como dispositivos médicos. Dentre esses dispositivos, podemos destacar aqueles que promovem a reparação tecidual e, também, a liberação controlada de fármacos. Partindo deste propósito, lentes de contato à base de celulose bacteriana (CB) foram desenvolvidas, visando o efeito curativo e reparativo para doenças da superfície ocular. A adição de ciclodextrinas (CDs) e fármacos, como o ciprofloxacino (CP) e o diclofenaco de sódio (DS) á essas lentes proporcionando propriedades terapêuticas e de liberação controlada dos fármacos. No entanto, para certificar-se do uso seguro desses compósitos pela indústria de dispositivos médicos, é necessário verificar se não possuem atividade citotóxica, genotóxica e/ou mutagênica. Sendo assim, a proposta do presente trabalho foi o desenvolvimento de uma adição eficaz de fármacos às lentes de contato de CB, para que sejam liberados de maneira controlada e, também, a verificação de sua biossegurança. Para essa verificação foram realizados ensaios in vitro de citotoxicidade (ensaio com o kit XTT e Sobrevivência Clonogênica), genotoxicidade (ensaio Cometa) e mutagenicidade (teste do Micronúcleo) com os respectivos. Após a análise estatística dos resultados foi possível verificar que o material CB-CP apresentou efeito citotóxico e os materiais CB-DS e CB-CD-DS apresentaram efeito citotóxico, genotóxico e mutagênico. Essa informação é fundamental para uma futura utilização segura desse biomaterial pela indústria de dispositivos médicos ...

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Este trabalho apresenta o estudo de dois sistemas de liberação prolongada, microemulsão e lipossomas, contendo peptídeo regulatório de fatores de crescimento, “osteogenic growth peptide” OGP, para aplicação em regeneração óssea. A base de adsorção para estes sistemas de liberação foi a celulose bacteriana (CB) produzida pela bactéria Gluconacetobacter xylinus. Foi escolhida devido às suas propriedades físicas e químicas, tais como como alta resistência à corrosão química, bio absorção, biocompatibilidade, porosidade e ainda boa resistência mecânica, o que a torna um biopolímero com grande potencial a ser explorado pela ciência biomédica. Estudos in vitro foram realizados para avaliar o perfil de liberação do peptídeo dos diferentes sistemas de liberação prolongada. O peptídeo OGP foi sintetizado pelo método da fase sólida (estratégia SPFS Fmoc); foi purificado e caracterizado por HPLC, espectrometria de massas e análise de aminoácidos e, em seguida, marcados com 5,6 carboxifluoresceína (CF) para análise por espectroscopia de fluorescência. O peptídeo marcado foi incorporado aos sistemas de liberação no momento do respectivo preparo, foram adsorvidos na CB por um período de 72h, seguido de sua liberação prolongada em sistema fechado de fluxo constante contendo tampão PBS pH 7,4, por um período de 24h. Após a análise da liberação, observou se que o sistema que obteve melhor resultado foi a microemulsão, sendo sua liberação prolongada nas primeiras 6,5 h, liberando 21,5% do valor teórico de peptídeo incorporado, seguido de uma liberação constante a partir desse período. Dessa forma, tem se que a microemulsão pode ser um sistema promissor para liberação prolongada do OGP em processos de regeneração óssea

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Chromatoid body (CB) is a typical cytoplasmic organelle of germ cells, and it seems to be involved in RNA/protein accumulation for later germ-cell differentiation. Despite most of the events in mammals spermatogenesis had been widely described in the past decades and the increase in the studies related to the CB molecular composition and physiology, the origins and functions of this important structure of male germ cells are still unclear. The aims of this study were to describe the nucleolar cycle and also to find some relationship between the nucleolar organization and the CB assembling during the spermatogenesis in mammals. Cytochemical and cytogenetics analysis showed nucleolar fragmentation in post-pachytene spermatocytes and nucleolar reorganization in post-meiotic spermatids. Significant difference in the number and in the size of nucleoli between spermatogonia and round spermatids, as well as differences in the nucleolar position within the nucleus were also observed. Ultrastructural analysis showed the CB assembling in the cytoplasm of primary spermatocytes and the nucleolar fragmentation occurring at the same time. In conclusion our results suggest that the CB may play important roles during the spermatogenesis process in mammals and that its origin may be related to the nucleolar cycle during the meiotic cell cycle.

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In the present work we made a review on the cytoplasmic organelle chromatoid body (CB) in the Insecta class. We note that the CB has been described in 14 orders of insects. However, we emphasize the importance of new orders should be analyzed, since the detailed knowledge of the reproductive biology of insects may help in understanding taxonomic, evolutionary and mainly contribute to the development of tools that minimize the populations of vectors and insect pests, contributing directly to human welfare.