Cellulose-Based Bio- and Nanocomposites: A Review

Cellulose macro- and nanofibers have gained increasing attention due to the high strength and stiffness, biodegradability and renewability, and their production and application in development of composites. Application of cellulose nanofibers for the development of composites is a relatively new research area. Cellulose macro- and nanofibers can be used as reinforcement in composite materials because of enhanced mechanical, thermal, and biodegradation properties of composites. Cellulose fibers are hydrophilic in nature, so it becomes necessary to increase their surface roughness for the development of composites with enhanced properties. In the present paper, we have reviewed the surface modification of cellulose fibers by various methods. Processing methods, properties, and various applications of nanocellulose and cellulosic composites are also discussed in this paper.

Evolução da biodegradabilidade da matéria orgânica em um sistema de lagoas de estabilização

Waste stabilization ponds (WSP) have been widely used for sewage treatment in hot climate regions because they are economic and environmentally sustainable. In the present study a WSP complex comprising a primary facultative pond (PFP) followed by two maturation ponds (MP-1 and MP-2) was studied, in the city of Natal-RN. The main objective was to study the bio-degradability of organic matter through the determination of the kinetic constant k throughout the system. The work was carried out in two phases. In the first, the variability in BOD, COD and TOC concentrations and an analysis of the relations between these parameters, in the influent raw sewage, pond effluents and in specific areas inside the ponds was studied. In the second stage, the decay rate for organic matter (k) was determined throughout the system based on BOD tests on the influent sewage, pond effluents and water column samples taken from fixed locations within the ponds, using the mathematical methods of Least Squares and the Thomas equation. Subsequently k was estimated as a function of a hydrodynamic model determined from the dispersion number (d), using empirical methods and a Partial Hydrodynamic Evaluation (PHE), obtained from tracer studies in a section of the primary facultative pond corresponding to 10% of its total length. The concentrations of biodegradable organic matter, measured as BOD and COD, gradually reduced through the series of ponds, giving overall removal efficiencies of 71.95% for BOD and of 52.45% for COD. Determining the values for k, in the influent and effluent samples of the ponds using the mathematical method of Least Squares, gave the following values respectively: primary facultative pond (0,23 day-1 and 0,09 day-1), maturation 1 (0,04 day-1 and 0,03 day-1) and maturation 2 (0,03 day-1 and 0,08 day-1). When using the Thomas method, the values of k in the influents and effluents of the ponds were: primary facultative pond (0,17 day-1 and 0,07 day-1), maturation 1 (0,02 day-1 and 0,01 day-1) and maturation 2 (0,01 day-1 and 0,02 day-1). From the Partial Hydrodynamic Evaluation, in the first section of the facultative pond corresponding to 10% of its total length, it can be concluded from the dispersion number obtained of d = 0.04, that the hydraulic regime is one of dispersed flow with a kinetic constant value of 0.20 day-1

Remoção de Microalgas de efluentes de lagoas de estabilização utilizando biofiltro

This research evaluated the microalgae removal produced in a stabilization pond system using biofilters as post-treatment, besides characterizing the effluents of stabilization ponds and filters in relation to concentrations of algal biomass (chlorophyll a and suspended solids), organic matter (BOD and COD), total phosphorus, orthophosphate, pH and dissolved oxygen, and tried to correlate physicochemical parameters with chlorophyll "a". It was held at the Ponta Negra ETE which is constituted by three stabilization ponds, with a primary facultative pond and two of maturation. For the algae removal were used two submerged bio-filters: the filter FPF (Facultative Pond Filter), fed with facultative pond effluent; and the filter MPF (Maturation Pond Filter), fed with second maturation pond effluent. The filling material of both filters was predominantly gravel no. 2, although it contains portions of gravel no. 1 and no. 3. The filters operating conditions were bad, they were nearly 10 years without maintenance, without cleaning or removal of sludge since the time of its construction, and part of the filling material may be obstruct. Despite poor operating conditions were obtained satisfactory results, in level of posttreatment. Removal efficiencies in relation to BOD and COD were 7 and 25% in FPF and 9 and 19% and in MPF, respectively. In relation to TSS efficiencies in MPF and FPF were 37 and 20%, respectively. As for the chlorophyll "a" removal, the FPF efficiency was 44% and the MPF was 40%. There was 50% of consumption of dissolved oxygen, on average, within the filters. Two profiles were performed in the filters, and it was possible to conclude that variations throughout the day were not statistically significant, and that, regardless of the time of collection, they would have the same representation comparing to the time of data collection (7 am) and the daily average, although individual variations throughout the day have been shown to be significant. Another important observation is that the correlations between Chlorophyll a and TSS were bigger and more significant in the effluent of the filters than in the effluent of the ponds

Mapeamento do biovolume de plantas aquáticas submersas a partir de dados hidroacústicos e imagem multiespectral de alta resolução

As plantas aquáticas têm papel fundamental no equilíbrio dos ecossistemas, porém seu crescimento desequilibrado pode obstruir canais, represas e reservatórios e afetar múltiplos usos da água. em relação a plantas aquáticas submersas, a utilização de medidas de controle torna-se mais complexa, em face da dificuldade em mapear e quantificar volumetricamente as áreas colonizadas. Nessas situações, considera-se que o uso de dados hidroacústicos possibilite o mapeamento e a mensuração dessas áreas, auxiliando na elaboração de propostas de manejo sustentáveis desse tipo de vegetação aquática. Assim, o presente trabalho utilizou dados acústicos e a técnica de krigagem para realizar a inferência espacial do biovolume de plantas aquáticas submersas. Os dados foram obtidos em três levantamentos ecobatimétricos realizados em uma área de estudos localizada no rio Paraná, caracterizada por condições favoráveis para proliferação de vegetação aquática submersa e dificuldade de navegação. Para delimitar as áreas caracterizadas pela presença de plantas aquáticas submersas, utilizou-se uma imagem multiespectral de alta resolução espacial World View-2. O mapeamento do biovolume das plantas aquáticas submersas nas áreas de ocorrência do fenômeno foi realizado a partir da inferência do biovolume por krigagem e do fatiamento dos valores inferidos em intervalos de 15%. A partir do mapa gerado, foi possível identificar os locais de maior concentração de macrófitas submersas, com predominância de valores de biovolume entre 15-30% e 30-45%, confirmando a viabilidade da utilização da krigagem na inferência espacial do biovolume, a partir de medidas ecobatimétricas georreferenciadas e com o suporte de imagem de alta resolução espacial.

Selective activity of butyrylcholinesterase in serum by a chemiluminescent assay

In a previous study, we showed that purified commercial esterase activity can be detected in a chemiluminescent assay based on the hydrolysis of 2-methyl-1-propenylbenzoate (MPB) to 2-methyl-1-propenol, which is subsequently oxidized by the horseradish peroxidase (HRP)-H2O2 system. The purpose of this study was to verify the applicability of this assay to human serum. The existence of an esterase activity capable of hydrolysing MPB is indicated by the fact that the MPB-scruin-HRP-H2O2 System consumes oxygen and emits light. Both signals were abolished by prior serum heat inactivation and were preserved when serum was stored at less than or equal to4 degreesC. Addition of aliesterase inhibitors, such as fluoride ion and trichlorfon or the cholinesterase inhibitor eserine, totally prevents light emission. The butyrylcholinesterase-specific substrate benzoylcholine causes a delay in both O-2 uptake and light emission, while the specific acetylcholinesterase substrate, acetyl-beta -methylcholine, had practically no effect. Purified butyrylcholinesterase, but not acetylcholinesterase, triggered light emission. The finding that butyryleholinesterase is responsible for the hydrolysis of MPB in serum should serve as the basis for the development of a specific chemiluminescent assay for this enzyme. Copyright (C) 2001 John Wiley & Sons, Ltd.

Foucault e a (bio) política: possibilidades e metamorfose de um conceito

The fundamental question developed in this research is to consider the possible meanings of biopolitics in the thought of Michel Foucault. In the first chapter of this study seeks to examine the rationality of biopower. It is able to show the rationality of acting as a social machinery for the manufacture of the subjectivity of individuals, biopolitics as a producer of bodies and subjectivity. The theme of biopolitics appears as inspiration of Nietzsche's metaphor of war. The idea that history is the war for dominance of the bodies. In the second chapter, the (bio) political will and political thought of resistance, fighting criticism as an attitude of revolt of the subject before his condition subjugated. The biopolitical here is intended as a conceptual tool for reading the thought / Foucault's work. A resistance that can be thought of as a biopolitical as a "refractoriness reflected". The third chapter will seek to show how the Foucault argues that power was already present the ethics of self-care. If the subject is a product, is captured by the discourse of biopower that manufactures its subjectivity, self care, it's time to think about the inner contents. Self care is something that offers resistance, as a possibility to think that these contents are constructed historically, and that therefore it is possible to reestablish the self-care is a policy of fighting these sedimented content that promotes colonization of the subjects. You can move from ruler to ruled itself, although this pursuit of liberty is always unfinished, always be a tension, a desire for freedom that can be undertaken not as a state, but at least the minimum and temporarily in other forms of existence, and other ways of relating, other ways of sociability, friendship, sexuality

Ativação local da rota da quinurenina por moduladores inflamatórios durante a meningite bacteriana.

Activation of the kynurenine (KYN) pathway (KP) by modulators of immune system has been observed during several neurological diseases. Here we assessed the association of chemo-/cytokine levels with the concentration of KP metabolites in cerebrospinal fluid (CSF) and plasma samples from patients with bacterial meningitis (BM). All samples were collected from 42 patients diagnosed with acute bacterial meningitis (ABM), aseptic meningitis, tuberculous meningitis and patients without infection neurological disorders. CSF and plasma concentration of metabolites from the KP was assessed by high pressure liquid chromatography (HPLC) and cytokines and chemokines by Bio-plex 200 suspension array system. Concentrations of the KP metabolites KYN and kynurenic acid (KYNA) were significantly higher in CSF of patients with ABM compared to other groups. Tryptophan (TRP), anthranilic acid (AA), 3-hydroxykynurenine (3HK) and 3-hydroxyanthranilic acid (3HAA) did not show statistical significance, although some of them presented a good accumulation during ABM. The expression of TNF-alpha, IL-6, IL-1beta, IFN-gamma, IL-10, IL-1 receptor antagonist (IL-1Ra), MIP-1alpha, MIP-1beta, MCP-1 and G-CSF was about 100-fold higher in CSF from ABM patients than other infected groups. In all CSF and plasma samples, the concentration of IL-2, IL-12(p70), IL-4, IL-8 and GM-CSF was not significant. ABM still showed significant concentrations of IL-6, IL-10, IL-1Ra and MCP-1 in plasma samples. Based on the comparison of KP metabolites concentrations between plasma and CSF samples we conclude that the activation of the tryptophan pathway upon BM occurs within the brain. This increase in KP metabolites is most due to activation of the KP by molecules as IFN-gamma and TNF-alpha in response to infection.

Método multirresíduo para monitoramento de contaminação ambiental de pesticidas na região de Bauru (SP) usando mel como bio-indicador

The presence of residues of the major groups of pesticides (organohalogen, organophosphorous, pyrethroids and organonitrogen) in representative samples of honey produced in Bauru (state of São Paulo, Brazil) was investigated from 1999 through2004. A multiresidue method was applied to honey samples to determine 48 pesticides with recoveries ranging from 76 to 95%. The limits of detection found were lower than 10 µg/kg for GC-MS-SIM. The results indicated that most pesticides found in the samples belonged to the organohalogen and organonitrogen groups. Residues of malathion were detected in almost all of the samples in high concentration.

Arquitetura, litofácies e evolução tectonoestratigráfica da bacia do rio do peixe, nordeste do Brasil

The Rio do Peixe Basin is located in the border of Paraíba and Ceará states, immediately to the north of the Patos shear zone, encompassing an area of 1,315 km2. This is one of the main basins of eocretaceous age in Northeast Brazil, associated to the rifting event that shaped the present continental margin. The basin can be divided into four sub-basins, corresponding to Pombal, Sousa, Brejo das Freiras and Icozinho half-grabens. This dissertation was based on the analysis and interpretation of remote sensing products, field stratigraphic and structural data, and seismic sections and gravity data. Field work detailed the lithofacies characterization of the three formations previously recognised in the basin, Antenor Navarro, Sousa and Rio Piranhas. Unlike the classical vertical stacking, field relations and seismostratigraphic analysis highlighted the interdigitation and lateral equivalency between these units. On bio/chrono-stratigraphic and tectonic grounds, they correlate with the Rift Tectonosequence of neocomian age. The Antenor Navarro Formation rests overlies the crystalline basement in non conformity. It comprises lithofacies originated by a braided fluvial system system, dominated by immature, coarse and conglomeratic sandstones, and polymict conglomerates at the base. Its exposures occur in the different halfgrabens, along its flexural margins. Paleocurrent data indicate source areas in the basement to the north/NW, or input along strike ramps. The Sousa Formation is composed by fine-grained sandstones, siltites and reddish, locally grey-greenish to reddish laminated shales presenting wavy marks, mudcracks and, sometimes, carbonate beds. This formation shows major influence of a fluvial, floodplain system, with seismostratigraphic evidence of lacustrine facies at subsurface. Its distribution occupies the central part of the Sousa and Brejo das Freiras half-grabens, which constitute the main depocenters of the basin. Paleocurrent analysis shows that sediment transport was also from north/NW to south/SE

Regulation and action of fibroblast growth factor 17 in bovine follicles

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

Effect of occlusal splint thickness on electrical masticatory muscle activity during rest and clenching

The extent of separation between the maxillary and mandibular teeth in the fabrication of interocclusal splints designed to achieve efficiency and muscle relaxation is controversial and undefined in the literature. Based on this premise, the aim of this study was to evaluate the effect of interocclusal splint thicknesses of 3 and 6 millimeters on the electrical activity of the anterior temporal and masseter muscles during rest and dental clenching. Twenty asymptomatic individuals (10 males and 10 females) were selected using the Research Diagnostic Criteria (RDC). Electromyography (EMG) was performed both with and without the 3- and 6-mm splints using the Bio EMG software package, which recorded values given in microvolts (mu V). The results, which were assessed using analysis of variance (ANOVA) to a 5% significance level (p < 0.05), showed increased electrical activity of the masticatory muscles during dental clenching compared with at rest, with greater activity in the masseter muscle. The electrical activity did not differ according to the thickness of the splints or between males and females. We can conclude that both splint thicknesses are effective in treating muscle hyperactivity given their similar clinical behavior for asymptomatic individuals.

Effect of a calcium hydroxide/chlorhexidine paste as intracanal dressing in human primary teeth with necrotic pulp against Porphyromonas gingivalis and Enterococcus faecalis

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