13 resultados para Retaining

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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This study aimed to assess the prevalence of aggressive periodontitis (AgP), and to investigate the association between demographic, socioeconomic and behavioral risk indicators with AgP in an untreated and isolated young population in Southeastern Brazil. For this cross-sectional survey, 134 subjects aged 12-29 years were selected by a census. Of those eligible, 101 subjects received a full-mouth clinical examination, and were interviewed using a structured written questionnaire. Cases were defined as individuals with 4 or more teeth with attachment loss > 4 mm or > 5 mm in the age groups 12-19 and 20-29, respectively. Overall, 9.9% of the subjects presented AgP (10.3% of the 12-19-year-olds and 9.7% of the 20-29-year-olds). The only risk indicator significantly associated with AgP in this isolated population was a high proportion of sites (> 30%) presenting supragingival calculus [OR = 23.2]. Having experienced an urgency dental treatment was a protective factor for AgP [OR = 0.1]. The authors concluded that this isolated and untreated population from Brazil presented a high prevalence of AgP. Local plaque-retaining factors played a major role in the prevalence of AgP in this isolated population, and should be included in further studies evaluating this destructive periodontal disease form.

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O lodo de esgoto doméstico é um resíduo gerado durante os processos de tratamento de esgoto, podendo ser estabilizado por diversos processos químicos, físicos e biológicos. O lodo de esgoto estabilizado (biossólido) não possui um destino final adequado e gera diversos problemas no sentido de sua disposição final. Dentre os muitos processos que visam à disposição do biossólido, destaca-se a reciclagem agrícola. A utilização da vermicompostagem como meio de estabilização do lodo de esgoto mostra-se como uma ferramenta útil na estabilização deste resíduo. O processo de vermicompostagem apresentou características físico-químicas satisfatórias para ser utilizado como técnica de estabilização do lodo de esgoto doméstico. O produto final apresentou potencial para ser utilizado na agricultura como fertilizante ou condicionador de solos.

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OBJETIVO: Descrever a autopercepção de saúde bucal em idosos e analisar fatores sociodemográficos e clínicos associados. MÉTODOS: Estudo transversal com 876 participantes em amostra representativa de idosos (65 anos ou mais) de Campinas, SP, em 2008-2009. Os exames odontológicos seguiram critérios padronizados pela Organização Mundial da Saúde para levantamentos epidemiológicos de saúde bucal. A autopercepção da saúde bucal foi avaliada pelo índice Geriatric Oral Health Assessment Index (GOHAI). Os indivíduos foram classificados segundo características sociodemográficas, odontológicas e prevalência de fragilidade biológica. O estudo de associações utilizou análise de regressão de Poisson; a análise considerou os pesos amostrais e a estrutura complexa da amostra por conglomerados. RESULTADOS: A média de idade dos indivíduos foi de 72,8 anos; 70,1% eram mulheres. A proporção de indivíduos com mais de 20 dentes presentes foi 17,2%; 38,2% usavam prótese dentária total em ambos os arcos; 8,5% necessitavam desse recurso em ao menos um arco dentário. Em média, o índice GOHAI foi elevado: 33,9 (máximo possível 36,0). Manter 20 dentes ou mais, usar prótese total nos dois arcos, não necessitar desse tratamento, não apresentar alterações de mucosa oral e não apresentar fragilidade biológica foram os fatores significantemente associados com melhor autopercepção de saúde bucal (p < 0,05). CONCLUSÕES: A avaliação de autopercepção em saúde bucal permitiu identificar os principais fatores associados a esse desfecho. Esse instrumento pode contribuir para o planejamento de serviços odontológicos, orientando estratégias de promoção em saúde voltadas à melhora da qualidade de vida das pessoas desse grupo etário.

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Study of surface electric charges of soil colloids helps in understanding the physicochemical phenomena that influence the capacity of retaining nutrients and their availability to plants. The structural charge (sigma(0), (min)), the variable charge (sigma(q, min)), and the organic matter (OM) charge (sigma(total) (OM)) of 12 tropical soils with contrasting mineralogies were evaluated based on the difference of selectivity for Cs(+) and Li(+) between the functional ionizable surfaces groups and the mineral 2:1 siloxane surface. Soils were divided into three groups: G1, soils with a predominance of kaolinite and gibbsite in the clay fraction; G2, soils with hydroxy-interlayered 2:1 minerals; and G3, soils with smectite but without hydroxy-interlayered 2:1 minerals. The Cs absorption method was efficient for detecting the charge components in tropical soils. The mineral structural charge contributed 11% and 16%, 28% and 31%, and 52% and 59% of total soil charge of A and B horizons of soils from groups G 1, G2, and G3, respectively. On the other hand, OM contributed 53% and 37%, 48% and 41%, and 21% and 20% of total charge for the same samples, respectively, In highly weathered soils of group G I and, to a lesser extent, in soils in group G2, surface charges depended mainly on their variable components, resulting from the OM (sigma(toal) (OM)), as well as from imperfections found in 1:1 minerals (sigma(q, min)). The importance of OM in determining the magnitude of electric charges in humid tropical soils is highlighted.

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The effects of different cooking conditions such as soaking, atmospheric (100 degrees C) or pressure boiling (121 degrees C), and draining of cooking water following thermal treatment on phenolic compounds and the DPPH radical scavenging capacity from two selected Brazilian bean cultivars (black and yellow-brown seed coat color) were investigated using a factorial design (2(3)). Factors that significantly reduced the total phenolic contents and antioxidant capacity in both cultivars were the soaking and draining stage. Independent of cooking temperature, total phenolics and antioxidant capacities were enhanced in treatments without soaking and where cooking water was not discarded, and this was likely linked to an increase of specific phenolic compounds detected by high performance liquid chromatography such as flavonols and free phenolic acids in both cultivars. Cooking of beans either at 100 or 121 degrees C, without a soaking stage and keeping the cooking water, would be recommendable for retaining antioxidant phenolic compounds.

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Rutin is employed as antioxidant and to prevent the capillary fragility and, when incorporated in cosmetic emulsions, it must target the action site. In vitro cutaneous penetration studies through human skin is the ideal situation, however, there are difficulties to obtain and to maintain this tissue viability. Among the membrane models, shed snake skin presents itself as pure stratum corneum, providing barrier function similar to human and it is obtained without the animal sacrifice. The objectives of this research were the development and stability evaluation of a cosmetic emulsion containing rutin and propylene glycol (penetration enhancer) and the evaluation or rutin in vitro cutaneous penetration and retention from the emulsion, employing an alternative model biomembrane. Emulsion was developed with rutin and propylene glycol, both at 5.0% w/w. Active substance presented on the formulation was quantified by a validated spectrophotometric method at 361.0 nm. Rutin Rutin cutaneous penetration and retention was performed in vertical diffusion cells with shed snake skin of Crotalus durissus, as alternative model biomembrane, and distilled water and ethanol 99.5% (1:1), as receptor fluid. The experiment was conducted for six hours, at 37.0 +/- 0.5 degrees C with constant stirring of 300 rpm. Spectrophotometry at 410.0 nm, previously validated, determined the active substance after cutaneous penetration/ retention. Emulsion did not promote rutin cutaneous penetration through C. durissus skin, retaining 0.931 +/- 0.0391 mu g rutin/mg shed snake skin. The referred formulation was chemically stable for 30 days after stored at 25.0 +/- 2.0 degrees C, 5.0 +/- 0.5 degrees C and 45.0 +/- 0.5 degrees C. In conclusion, it has not been verified the active cutaneous penetration through the model biomembrane, but only its retention on the Crotalus durissus stratum corneum, condition considered stable for 30 days.

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Microencapsulation of Lippia sidoides essential oil was carried out by spray drying. Blends of maltodextrin and gum arabic were used as carrier. Spray dried microparticles were characterized using conventional (thermogravimetry, evolved gas analysis) and combined (thermogravimetry-mass spectrometry analysis) thermal analysis techniques in order to evaluate the abilities of carriers with different compositions in retaining and in releasing the core vs. dynamic heating. Thermal analysis was useful to evaluate the physico-chemical interactions between the core and carriers and to determine the protective effect of the carriers on the evaporation of essential oil.

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Galectin-1 (Gal-1) regulates leukocyte turnover by inducing the cell surface exposure of phosphatidylserine (PS), a ligand that targets cells for phagocytic removal, in the absence of apoptosis. Gal-1 monomer- dimer equilibrium appears to modulate Gal-1-induced PS exposure, although the mechanism underlying this regulation remains unclear. Here we show that monomer- dimer equilibrium regulates Gal-1 sensitivity to oxidation. A mutant form of Gal-1, containing C2S and V5D mutations (mGal-1), exhibits impaired dimerization and fails to induce cell surface PS exposure while retaining the ability to recognize carbohydrates and signal Ca(2+) flux in leukocytes. mGal-1 also displayed enhanced sensitivity to oxidation, whereas ligand, which partially protected Gal-1 from oxidation, enhanced Gal-1 dimerization. Continual incubation of leukocytes with Gal-1 resulted in gradual oxidative inactivation with concomitant loss of cell surface PS, whereas rapid oxidation prevented mGal-1 from inducing PS exposure. Stabilization of Gal-1 or mGal-1 with iodoacetamide fully protected Gal-1 and mGal-1 from oxidation. Alkylation-induced stabilization allowed Gal-1 to signal sustained PS exposure in leukocytes and mGal-1 to signal both Ca(2+) flux and PS exposure. Taken together, these results demonstrate that monomer-dimer equilibrium regulates Gal-1 sensitivity to oxidative inactivation and provides a mechanism whereby ligand partially protects Gal-1 from oxidation.

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Purpose: To investigate the proliferative behavior of the corneal and limbal epithelia after debridement on the central region of the rabbit cornea. Methods: After scraping a circular epithelial area, 5 mm in diameter, in the center of the cornea, (3)H-thymidine ((3)H-TdR) was injected intravitreally, and the rabbits killed from 1 to 49 days afterward. The cornea, together with the adjacent conjunctiva, was processed for autoradiography. Results: The regenerating epithelium at the center of the cornea exhibited high frequencies of labeled nuclei when compared to controls. The mitotic indexes for the limbus were comparable in experimental and control eyes. The unique basal stratum of the limbal epithelium exhibited quick proliferation and vertical migration in all eyes. Cells that remained labeled for four weeks or more were observed throughout the corneal epithelium, including its basal stratum, and this did not depend on epithelial damage. Conclusion: Corneal epithelium wounds are healed by sliding and proliferation of cells surrounding the epithelial gap without any evidence for the participation of the limbal epithelium. Daughter cells labeled with (3)H-TdR were visualized in all layers of the corneal epithelium up to 7 weeks after the DNA precursor injection. However, at this long interval, the only labeled cells in the limbus were in the suprabasal layers.

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The investigation was centered on the morphological features of the conjunctiva-cornea transition (limbus) of the rabbit eye and the proliferative behavior of its epithelium. The eyes were processed for examination with light and electron microscopy, as well as for autoradiography after intravitreal injection of [H-3]thymidine ([H-3]TdR). At the sites of extraocular muscle insertion, the vascularization of the stroma extended to the peripheral cornea, and the limbal epithelium was thin with its basal stratum made up by clear cuboidal cells. In between the muscle insertions, the cuboidal clear cells, as well as the stroma blood vessels; were scarce. At the light microscope level, the basement membrane was distinct in the cornea but not in the limbus or the conjunctiva. Autoradiographs demonstrated that, at the limbus, the basal cells migrated very quickly to the suprabasal region and remained there up to the 28-day interval. Labeled cells were identified in all epithelial layers of the cornea, including the basal one, at 21 and 28 days but not in the limbal basal clear cells. The rate of renewal of conjunctival epithelium was similar to that observed for the transition with scarce clear cells. The high-resolution autoradiographs demonstrated that the basal cuboidal clear limbal cells exhibit a quick renewal and that they are not label-retaining cells. These latter ones were detected all over the corneal epithelium and in the suprabasal layers of the limbus up to 28 days, in physiological conditions, without the need of stimulation by damage to the corneal epithelium.

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Two new species of Cnemidophorus are described from the right bank of the Sao Francisco river, in the northwestern part of state of Bahia, Brazil. Both species are assigned to the Cnemidophorus ocellifer group and are distinguished from all other congeners on the basis of lepidosis and color pattern. One of them, Cnemidophorus cyanurus, shares with the species of the subgroup of C. littoralis (C. abaetensis, C. littoralis and C. venetacaudus), a bluish green tail, spurs on the heels of males, 6-7 supraciliaries, a high number of femoral pores (27-45), a row of enlarged scales in the dorsal part of the humerus, and 8 to 10 rows of ventral scales. The second species, Cnemidophorus nigrigula, shares with the C. ocellifer subgroup (composed of C. ocellifer, C. mumbuca, C. jalapensis and C. confusionibus) a low number of femoral pores (1421), enlarged scales in the temporal region posterior to the third subocular, 5 supraciliaries, 6 to 8 rows of ventral scales, and a brown tail color. It is also characterized by males being conspicuously larger than females and by females retaining the juvenile color pattern, which is lost in adult males. The latter characteristic has not been reported in any species of the C. ocellifer group before now. The two new species occur sympatrically at Santo Inacio.

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The Cooks kinetic method has been very convenient to correlate the relative dissociation rates obtained by collision-induced fragmentation experiments with the energies of two related bonds in molecules and complexes in the gas phase. Reliable bond energy data are, however, not always available, particularly for polynuclear transition-metal complexes, such as the triruthenium acetate clusters of the general formula [Ru(3) (mu(3)-O)(mu-CH(3)COO)(6)(py)(2)(L)](+), where L = ring substituted N-heterocyclic ligands. Accordingly, their gas-phase collision-induced tandem mass spectrometry (CID MS/MS) dissociation patterns have been analyzed pursuing a relationship with the more easily accessible redox potentials (E(1/2)) and Lever`s E(L) parameters. In fact, excellent linear correlations of In(1/2A(L)/A(py)), where A(py) and A(L) are the abundance of the fragments retaining the pyridine (py) and L ligand, respectively, with E(1/2) and E(L) were found. This result shows that those electrochemical parameters are correlated with bond energies and can be used in the analysis of the dissociation data. Such modified Cooks method can be used, for example, to determine the electronic effects of substituents on the metal-ligand bonds for a series of transition-metal complexes. Copyright (C) 2008 John Wiley & Sons, Ltd.

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Cellulase is an enzymatic complex which synergically promotes the degradation of cellulose to glucose. The adsorption behavior of cellulase from Trichoderma reesei onto Si wafers or amino-terminated surfaces was investigated by means of ellipsometry and atomic force microscopy (AFM) as a function of temperature. Upon increasing temperature from (24 +/- 1) to (60 +/- 1) degrees C, adsorption of cellulase became faster and more pronounced and the mean roughness of cellulase adsorbed layers increased. In the case of cellulase adsorbed onto Si wafers, Arrhenius`s plot allowed us to estimate the adsorption energy as 24.2 kJ mol(-1). The hydrolytic activity of free cellulase and cellulase immobilized onto Si wafers was tested using cellulose dispersions as substrates. The incubation temperature ranged from (37 +/- 1) to (60 +/- 1) degrees C. The highest efficiency was observed at (60 +/- 1) degrees C. The amount of glucose produced by free cellulase was similar to 20% higher than that obtained from immobilized cellulase. However, immobilizing cellulase onto Si wafers proved to be advantageous because they could be reused six times while retaining their original activity level. Such an effect was attributed to surface hydration, which prevents enzyme denaturation. The hydrolytic activity of cellulase immobilized onto amino-terminated surfaces was slightly lower than that observed for cellulase adsorbed onto Si wafers, and reuse was not possible.