Layer-by-Layer Films Based on Carbon Nanotubes and Polyaniline for Detecting 2-Chlorophenol

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

Rhamnolipids Production by a Pseudomonas eruginosa LBI Mutant: Solutions and Homologs Characterization

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

Proliferação e Morte Celular (Apoptose) avaliadas em ratos Lewis após tratamento com mistura de praguicidas em baixas doses

The use of pesticides in Brazil has intensified over the years. And since 2009 it was ranked as the largest market for pesticides worldwide. The consequential diffuse contamination of the environment is therefore due to the increasing number of chemicals of different classes, origins and modes of action. Little is known about the action of pesticides on human health in situations of co-exposure. Possible toxic effects are not restricted to agricultural and industrial workers, but also the general population that may be exposed continuously to its residues in food and water. Although these pesticides are mostly present in the environment at low doses, it must be considered that possible cumulative or synergistic effects may occur when there are concurrent or sustained exposure for two or more of these agents, which can lead to late manifestation of subclinical damages, sometimes irreversible. Thus, the specific objective of this study was to assess the effect of carcinogenesis promotion of a mixture of pesticides at low doses and analyze the phenomena of cell proliferation and apoptosis in rat liver. A total of 50 male Lewis rats was separated into 5 groups for 8 weeks in a medium term hepatocarcinogenesis model. The three different classes of pesticides (dieldrin, dicofol, endosulfan, dichlorvos and permethrin), whose residues were detected by ANVISA during the period from 2001 to 2005 in tomatoes cultures, were added to the feed of rats initiated to hepatocarcinogenesis with diethylnitrosamine (DEN- 200mg/kg ip). We used two different mixtures, one with no toxic effects at doses (MEX1) referring to the NOEL (no-observed-effect level) and another at doses LOEL / LEL / LOAEL (Lowest-observed-effect level / Lowest-effect level / Lowest -observed-adverse-effect level), to the installation of adverse effects (MEX2), derived from chronic studies. All animals ...(Complete abstract click electronic access below)

Study of thermal decomposition of ignition temperature of bagasse, coal and their blends

In Brazil, due to its availability, sugar cane bagasse has a high potential for power generation. The knowledge of ignition behavior, as well as the knowledge of the chemical kinetics, in of fuels combustion process is important features in boilers projects and in the stability of the combustion process control. The aim of this study is to investigate the thermal behavior of sugar cane bagasse, coal and their blends. The methodology proposed by Tognotti et al. (1985) was applied to determine the ignition temperature for all samples. Ignition temperatures were 256oC for neat bagasse and 427oC for neat coal, and 275oC for both blends (50-50% and 25-75%). The ModelFree Kinetics was applied to determine the apparent activation energy (Eα) of the thermal decomposition of sugar cane bagasse. For the two major events of mass loss of bagasse which correspond to the thermal decomposition of organic matter (mainly hemicellulose, cellulose and lignin), average values of Eα were obtained for both combustion and pyrolysis processes. In synthetic air atmosphere, the Eα were 170.8±26.3 kJ⋅mol-1 and 277.8±58.6 kJ⋅mol-1, while in nitrogen atmosphere, the Eα were 185.0 ± 11.4 kJ⋅mol-1 and 82.1±44.4 kJ⋅mol-1. The results obtained can be explained by synergistic effects when both bagasse and coal were blended, changing the fuel reactivity.

Action of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) on hatchability and embryogenesis of Rhipicephalus sanguineus eggs (Acari: Ixodidae)

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

Inhibition of nuclear factor-kappa B by dehydroxymethylepoxyquinomicin induces schedule-dependent chemosensitivity to anticancer drugs and enhances chemoinduced apoptosis in osteosarcoma cells

Osteosarcoma (OS) is the most common primary malignant bone tumor, usually developing in children and adolescents, and is highly invasive and metastatic, potentially developing chemoresistance. Thus, novel effective treatment regimens are urgently needed. This study was the first to investigate the anticancer effects of dehydroxymethylepoxyquinomicin (DHMEQ), a highly specific nuclear factor-kappa B (NF-kappa B) inhibitor, on the OS cell lines HOS and MG-63. We demonstrate that NF-kappa B blockade by DHMEQ inhibits proliferation, decreases the mitotic index, and triggers apoptosis of OS cells. We examined the effects of combination treatment with DHMEQ and cisplatin, doxorubicin, or methotrexate, drugs commonly used in OS treatment. Using the median effect method of Chou and Talalay, we evaluated the combination indices for simultaneous and sequential treatment schedules. In all cases, combination with a chemotherapeutic drug produced a synergistic effect, even at low single-agent cytotoxic levels. When cells were treated with DHMEQ and cisplatin, a more synergistic effect was obtained using simultaneous treatment. For the doxorubicin and methotrexate combination, a more synergistic effect was achieved with sequential treatment using DHMEQ before chemotherapy. These synergistic effects were accompanied by enhancement of chemoinduced apoptosis. Interestingly, the highest apoptotic effect was reached with sequential exposure in both cell lines, independent of the chemotherapeutic agent used. Likewise, DHMEQ decreased cell invasion and migration, crucial steps for tumor progression. Our data suggest that combining DHMEQ with chemotherapeutic drugs might be useful for planning new therapeutic strategies for OS treatment, mainly in resistant and metastatic cases. Anti-Cancer Drugs 23:638-650 (C) 2012 Wolters Kluwer Health broken vertical bar Lippincott Williams & Wilkins.

Comparative Studies of the (Anti) Mutagenicity of Baccharis dracunculifolia and Artepillin C by the Bacterial Reverse Mutation Test

Baccharis dracunculifolia is a plant native from Brazil, commonly known as 'Alecrim-do-campo' and 'Vassoura' and used in alternative medicine for the treatment of inflammation, hepatic disorders and stomach ulcers. Previous studies reported that artepillin C (ArtC, 3-{4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl}-2(E)-propenoic acid), is the main compound of interest in the leaves. This study was undertaken to assess the mutagenic effect of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE: 11.4-182.8 mu g/plate) and ArtC (0.69-10.99 mu g/plate) by the Ames test using Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and to compare the protective effects of Bd-EAE and ArtC against the mutagenicity of a variety of direct and indirect acting mutagens such as 4-nitro-O-phenylenediamine, sodium azide, mitomycin C, benzo[a]pyrene, aflatoxin B1, 2-aminoanthracene and 2-aminofluorene. The mutagenicity test showed that Bd-EAE and ArtC did not induce an increase in the number of revertant colonies indicating absence of mutagenic activity. ArtC showed a similar antimutagenic effect to that of Bd-EAE in some strains of S. typhimurium, demonstrating that the antimutagenic activity of Bd-EAE can be partially attributed to ArtC. The present results showed that the protective effect of whole plant extracts is due to the combined and synergistic effects of a complex mixture of phytochemicals, the total activity of which may result in health benefits.

Electrogeneration of platinum nanoparticles in a matrix of dendrimer-carbon nanotubes

Hybrid materials with enhanced properties can now be obtained by combining nanomaterials such as carbon nanotubes and metallic nanoparticles, where the main challenge is to control fabrication conditions. In this study, we demonstrate that platinum nanoparticles (PtNps) can be electrogenerated within layer-by-layer (LbL) films of polyamidoamine (PAMAM) dendrimers and single-walled carbon nanotubes (SWCNTs), which serve as stabilizing matrices. The advantages of the possible control through electrogeneration were demonstrated with a homogeneous distribution of PtNps over the entire surface of the PAMAM/SWCNT LbL films, whose electroactive sites could be mapped using magnetic force microscopy. The Pt-containing films were used as catalysts for hydrogen peroxide reduction, with a decrease in the reduction potential of 60 mV compared to a Pt film deposited onto bare ITO. By analyzing the mechanisms responsible for hydrogen peroxide reduction, we ascribed the enhanced catalytic activity to synergistic effects between platinum and carbon in the LbL films, which are promising for sensing and fuel cell applications.

Correlazioni tra proprietá reologiche, struttura e processabilitá di blend di LLDPE/LDPE

Polymer blends constitute a valuable way to produce relatively low cost new materials. A still open question concerns the miscibility of polyethylene blends. Deviations from the log-additivity rule of the newtonian viscosity are often taken as a signature of immiscibility of the two components. The aim of this thesis is to characterize the rheological behavior in shear and elongation of five series of LLDPE/LDPE blends whose parent polymers have been chosen with different viscosity and SCB content and length. Synergistic effects have been measured for both zero shear viscosity and melt strength. Both SCB length and viscosity ratio between the components have been found to be key parameters for the miscibility of the pure polymers. In particular the miscibility increases with increasing SCB length and with decreasing the LDPE molecular weight and viscosity. This rheological behavior has significant effects on the processability window of these blends when the uni or biaxial elongational flows are involved. The film blowing is one of the processes for which the synergistic effects above mentioned can be crucial. Small scale experiments of film blowing performed for one of the series of blends has demonstrated that the positive deviation of the melt strength enlarges the processability window. In particular, the bubble stability was found to improve or disappear when the melt strength of the samples increased. The blending of LDPE and LLDPE can even reduce undesired melt flow instability phenomena widening, as a consequence, the processability window in extrusion. One of the series of blends has been characterized by means of capillary rheometry in order to allow a careful morphological analysis of the surface of the extruded polymer jets by means of Scanning Electron Microscopy (SEM) with the aim to detect the very early stages of the small scale melt instabilty at low shear rates (sharksin) and to follow its subsequent evolution as long as the shear rate was increased. With this experimental procedure it was possible to evaluate the shear rate ranges corresponding to different flow regions: smooth extrudate surface (absence of instability), sharkskin (small scale instability produced at the capillary exit), stick-slip transition (instability involving the whole capillary wall) and gross melt fracture (i.e. a large scale "upstream" instability originating from the entrance region of the capillary). A quantitative map was finally worked out using which an assessment of the flow type for a given shear rate and blend composition can be predicted.

Phänotypische und funktionelle Eigenschaften humaner neonataler dentritischer Zellen

Humane Neugeborene leiden an einer erhöhten Anfälligkeit für Infektionskrankheiten. Die dendritischen Zellen (DC) werden für die beeinträchtigten neonatalen T-Helfer 1 (Th1) Immunantworten verantwortlich gemacht. Der Hauptaktivator der Differenzierung von Th1 Zellen ist Interleukin-12 (IL-12), ein Zytokin, welches in adulten, nicht aber in neonatalen DC vornehmlich nach Bindung der Toll-like Rezeptoren produziert wird. In der vorliegenden Arbeit wurde der potentielle Einfluss verschiedener TLR-Liganden auf die Initiierung neonataler Th1-Immunantworten untersucht. Einzelne TLR-Liganden induzierten die Reifung adulter DC, während die neonatalen DC erst nach simultaner Stimulierung von TLR3/TLR8 bzw. TLR4/TLR8 Reifungsmarker exprimierten. Der synergistische Effekt kombinierter TLR-Liganden zeigte sich sowohl in der adulten als auch der neonatalen Zytokinproduktion, wobei unterschiedliche Expressionsmuster für IL-1beta, IL-6, IL-8, IL-10, TNFalpha und vor allem IL-27 beobachtet wurden. Besonders IL-12p70 wurde von neonatalen DC ausschließlich nach kombinierter TLR-Stimulation produziert. Darüber hinaus wurde die Fähigkeit aktivierter DC analysiert, autologe T-Zellen zu polarisieren. Interessanterweise konnte beobachtet werden, dass die Überstände kombiniert stimulierter neonataler DC die Interferon-gamma Produktion in neonatalen naiven T-Zellen auslösten. Und somit konnte gezeigt werden, dass neonatale DC naive T-Zellen hinsichtlich einer Th1-Immunantwort polarisieren können. Letztendlich zeigen die Ergebnisse neue Möglichkeiten auf, potente Impfstrategien für Neugeborene zu entwickeln.

Polymer-nanoparticle composites: from orientation phenomena to optoelectronic applications

Polymer-nanoparticle hybrids show synergistic effects, demonstrating both, the unique properties of nanosized structures and the good processability and functionalities of polymeric materials. This work shows the synthesis and application of block copolymers containing a soluble, functional block and a short anchor block, which efficiently binds to the surface of nanocrystals. We functionalized anisotropic, semiconducting nanoparticles, which can be dissolved in organic and polymeric matrices upon modification. The modified nanorods have the ability to form liquid crystalline phases, which behave similar to low molecular liquid crystals with a reversible clearing behaviour. These liquid crystalline phases could also be obtained in hole conducting matrices. For a macroscopic orientation of the nanorods, electric fields were applied and a switching (in analogy to known liquid crystals) to a homeotropic orientation was observed.rnBy introduction of dye molecules in the anchor block of a hole conducting block copolymer, all essential components of a solar cell can be combined in a single particle. Light absorption of the dye induces the injection of electrons into the particles, followed by a charging, that was monitored by a special AFM technique.rnLight emitting nanocrystals were functionalized analogously with a hole transporting polymer. The stability of the particles could be enhanced by the sterically stabilizing polymer corona and the particles showed improved properties in terms of processing. We applied these hybrid materials in light emitting devices, which showed better characteristics due to an improved hole injection and well dispersed emitting particles in the active device layer.rnThe work shows the broad spectrum of properties and applications based on the synergistic effects in hybrid and composite materials.

Phosphonsäurehaltige polycyclische aromatische Kohlenwasserstoffe für Anwendungen in Brennstoffzellen

Die vorliegende Arbeit umfasst die Synthese und Charakterisierung phosphonsäurehaltiger, organischer Kristalle als ionenleitende Verbindungen in Brennstoffzellen-Anwendungen. Sie zielt dabei einerseits auf die Darstellung von protonenleitenden Polyphenylenverbindungen und deren Verwendung als Linker für den Aufbau protonenleitender Aluminium-Phosphonat-Netzwerke ab und behandelt andererseits die Einführung stark polarer Phosphonsäuregruppen in einen diskreten Nanographenkern sowie deren Einfluss auf die ionen- und elektronenleitenden Eigenschaften, um diese als gemischt-leitende Kompatibilisatoren an der isolierenden Elektrode/ Membran-Grenzfläche in einer Brennstoffzelle zu verwenden. Am Beispiel eines phosphonsäurefunktionalisierten, phenylenisch-expandierten Hexaphenylbenzols konnte ein solvothermisch stabiler Protonenleiter mit einer Selbstorganisation in kolumnare, supramolekulare Strukturen und hoher, temperaturunabhängiger Leitfähigkeit mit dominierendem Grotthuss-Anteil präsentiert werden. Durch einen Wechsel dieser 1D-radialen Phosphonsäureanordnung in der Molekülhülle hin zu 2D- und 3D-H2PO3-funktionalisierten, dendritischen Stäbchen- bzw. Kugelstrukturen konnte gezeigt werden, dass eine kolumnare Molekülanordnung jedoch kein notwendiges Kriterium für einen Grotthuss-artigen Protonentransport darstellt. Durch die mehrdimensionale Orientierung der Phosphonsäuren in der Außenhülle der Dendrimere garantieren die synthetisierten Strukturen hochaggregierte Phosphonsäurecluster, die als dichtes Säurekontinuum die eigentlichen protonenleitfähigen Kanäle darstellen und somit als entscheidendes Kriterium für das Auftreten eines Grotthuss-artigen Mechanismus definiert werden müssen. Eine signifikante Erhöhung der Leitfähigkeit konnte durch den Aufbau poröser, organisch-anorganischer Netzwerke (Al-HPB-NETs) über Komplexierung einer unterstöchiometrischen Menge an Aluminium-Kationen mit der Polyphosphonsäureverbindung Hexakis(p-phosphonatophenyl)benzol als Linkereinheit erfolgen, die anschließend mit kleinen intrinsischen Protonenleitern wie Phosphonsäure dotiert wurden. Diese dotierten Netzwerke wiesen außergewöhnliche Leitfähigkeit auf, da sie die σ-Werte des Referenzpolymers Nafion® bereits in einem Temperaturbereich oberhalb von 135°C übertrafen, aber gleichzeitig ein sehr gutes Säureretentionsverhalten von einem Gew.-% Säuredesorption über eine Immersionsdauer von 14 h gegenüber wässrigem Medium zeigten. Durch Mischen dieser Aluminiumphosphonate mit einer dotierten Polymermatrix wie PBI konnten synergistische Effekte durch zusätzliche attraktive H-Brückenbindungen zwischen molekular angebundener Phosphonsäure und mobiler H3PO4 an Hand eines signifikanten Leitfähigkeitsanstiegs für die resultierenden Membranen beobachtet werden. Die Protonenleitfähigkeit lag in diesen Materialien in dem gesamten untersuchten Temperaturbereich oberhalb von Nafion®. Durch das Einbringen der NETs in PBI konnte ebenfalls die Säureretention von PBI um etwa 9 % bei kurzen Immersionszeiten (bis 1 min) verbessert werden. Darüber hinaus wurde in der vorliegenden Arbeit die synthetische Kombination eines hydrophoben, elektronenleitenden Nanographenkerns mit einer, durch eine isolierende Peripherie getrennten, stark polaren, protonenleitenden Außenhülle realisiert. Am Beispiel von zwei phosphonsäurefunktionalisierten Triphenylenen, die sich in Länge und Planarität der gewählten Peripheriebausteine unterschieden, sollten polycyclische aromatische Kohlenwasserstoffe mit gemischt protonen- und elektronenleitenden Eigenschaften hergestellt werden, die über Impedanzspektroskopie und Vierpunktmessungen untersucht wurden. Da es sich bei der Anwendung solcher gemischtleitenden Verbindungen um grenz-flächenaktive Substanzen handelt, die das ohne verbesserte Anbindung bestehende Dielektrikum zwischen Elektrode und protonenleitender Membran überbrücken sollen, wurde die Untersuchung eines möglichen Elektronentransportes durch eine Molekülmonolage ebenfalls über kombinatorische STM- und STS-Technik durchgeführt.

Efficacy of psychological therapy in schizophrenia: conclusions from meta-analyses

Over the past years, evidence for the efficacy of psychological therapies in schizophrenia has been summarized in a series of meta-analyses. The present contribution aims to provide a descriptive survey of the evidence for the efficacy of psychological therapies as derived from these meta-analyses and to supplement them by selected findings from an own recent meta-analysis. Relevant meta-analyses and randomized controlled trials were identified by searching several electronic databases and by hand searching of reference lists. In order to compare the findings of the existing meta-analyses, the reported effect sizes were extracted and transformed into a uniform effect size measure where possible. For the own meta-analysis, weighted mean effect size differences between comparison groups regarding various types of outcomes were estimated. Their significance was tested by confidence intervals, and heterogeneity tests were applied to examine the consistency of the effects. From the available meta-analyses, social skills training, cognitive remediation, psychoeducational coping-oriented interventions with families and relatives, as well as cognitive behavioral therapy of persistent positive symptoms emerge as effective adjuncts to pharmacotherapy. Social skills training consistently effectuates the acquisition of social skills, cognitive remediation leads to short-term improvements in cognitive functioning, family interventions decrease relapse and hospitalization rates, and cognitive behavioral therapy results in a reduction of positive symptoms. These benefits seem to be accompanied by slight improvements in social functioning. However, open questions remain as to the specific therapeutic ingredients, to the synergistic effects, to the indication, as well as to the generalizability of the findings to routine care.

Ethanol Production from Hardboard Manufacturing Process Wastewater: Methods for Improving Product Yields from Hemicellulose Hydrolysates

Waste effluents from the forest products industry are sources of lignocellulosic biomass that can be converted to ethanol by yeast after pretreatment. However, the challenge of improving ethanol yields from a mixed pentose and hexose fermentation of a potentially inhibitory hydrolysate still remains. Hardboard manufacturing process wastewater (HPW) was evaluated at a potential feedstream for lignocellulosic ethanol production by native xylose-fermenting yeast. After screening of xylose-fermenting yeasts, Scheffersomyces stipitis CBS 6054 was selected as the ideal organism for conversion of the HPW hydrolysate material. The individual and synergistic effects of inhibitory compounds present in the hydrolysate were evaluated using response surface methodology. It was concluded that organic acids have an additive negative effect on fermentations. Fermentation conditions were also optimized in terms of aeration and pH. Methods for improving productivity and achieving higher ethanol yields were investigated. Adaptation to the conditions present in the hydrolysate through repeated cell sub-culturing was used. The objectives of this present study were to adapt S. stipitis CBS6054 to a dilute-acid pretreated lignocellulosic containing waste stream; compare the physiological, metabolic, and proteomic profiles of the adapted strain to its parent; quantify changes in protein expression/regulation, metabolite abundance, and enzyme activity; and determine the biochemical and molecular mechanism of adaptation. The adapted culture showed improvement in both substrate utilization and ethanol yields compared to the unadapted parent strain. The adapted strain also represented a growth phenotype compared to its unadapted parent based on its physiological and proteomic profiles. Several potential targets that could be responsible for strain improvement were identified. These targets could have implications for metabolic engineering of strains for improved ethanol production from lignocellulosic feedstocks. Although this work focuses specifically on the conversion of HPW to ethanol, the methods developed can be used for any feedstock/product systems that employ a microbial conversion step. The benefit of this research is that the organisms will the optimized for a company's specific system.

Using state variables to model the response of tumour cells to radiation and heat: a novel multi-hit-repair approach

In order to overcome the limitations of the linear-quadratic model and include synergistic effects of heat and radiation, a novel radiobiological model is proposed. The model is based on a chain of cell populations which are characterized by the number of radiation induced damages (hits). Cells can shift downward along the chain by collecting hits and upward by a repair process. The repair process is governed by a repair probability which depends upon state variables used for a simplistic description of the impact of heat and radiation upon repair proteins. Based on the parameters used, populations up to 4-5 hits are relevant for the calculation of the survival. The model describes intuitively the mathematical behaviour of apoptotic and nonapoptotic cell death. Linear-quadratic-linear behaviour of the logarithmic cell survival, fractionation, and (with one exception) the dose rate dependencies are described correctly. The model covers the time gap dependence of the synergistic cell killing due to combined application of heat and radiation, but further validation of the proposed approach based on experimental data is needed. However, the model offers a work bench for testing different biological concepts of damage induction, repair, and statistical approaches for calculating the variables of state.