Proteomics of the neurotoxic fraction from the sea anemone Bunodosoma cangicum venom: Novel peptides belonging to new classes of toxins

In contrast to the many studies on the venoms of scorpions, spiders, snakes and cone snails, tip to now there has been no report of the proteomic analysis of sea anemones venoms. In this work we report for the first time the peptide mass fingerprint and some novel peptides in the neurotoxic fraction (Fr III) of the sea anemone Bunodosoma cangicum venom. Fr III is neurotoxic to crabs and was purified by rp-HPLC in a C-18 column, yielding 41 fractions. By checking their molecular masses by ESI-Q-Tof and MALDI-Tof MS we found 81 components ranging from near 250 amu to approximately 6000 amu. Some of the peptidic molecules were partially sequenced through the automated Edman technique. Three of them are peptides with near 4500 amu belonging to the class of the BcIV, BDS-I, BDS-II, APETx1, APETx2 and Am-II toxins. Another three peptides represent a novel group of toxins (similar to 3200 amu). A further three molecules (similar to similar to 4900 amu) belong to the group of type 1 sodium channel neurotoxins. When assayed over the crab leg nerve compound action potentials, one of the BcIV- and APETx-like peptides exhibits an action similar to the type 1 sodium channel toxins in this preparation, suggesting the same target in this assay. On the other hand one of the novel peptides, with 3176 amu, displayed an action similar to potassium channel blockage in this experiment. In summary, the proteomic analysis and mass fingerprint of fractions from sea anemone venoms through MS are valuable tools, allowing us to rapidly predict the occurrence of different groups of toxins and facilitating the search and characterization of novel molecules without the need of full characterization of individual components by broader assays and bioassay-guided purifications. It also shows that sea anemones employ dozens of components for prey capture and defense. (C) 2008 Elsevier Inc. All rights reserved.

EPR and magnetic studies of a carboxylate-bridged dinuclear copper(II) compound: [cu2(flu)4(dmf)2]

We report magnetic and EPR (electron paramagnetic resonance) spectroscopy studies of [Cu2(flu)4(dmf)2] (flu = flufenamate and dmf = dimethylformamide), which has CuII ions in tetracarboxylate "paddle wheel" dinuclear units. Susceptibility measurements at 10 < T < 275 K allowed the evaluation of an antiferromagnetic intradinuclear exchange coupling J0 = -294 ± 5 cm-1 between CuII ions (Hex = "J0 S1·S2). EPR experiments at 300 K in powder and single-crystals at 9.5 and 34.4 GHz indicated g// = 2.373, g⊥ = 2.073 and zero field splitting parameters D = (-0.334 ± 0.001) cm"1 and E ca. 0. EPR signal intensity measurements at X-band in the range 4 < T < 295 K indicated that J0 = "283 ± 5 cm"1. A higher limit |J´| < 5×10-3 cm-1 for the interdinuclear exchange coupling between neighbor units at ca.14.24 Å was estimated from the angular variation of the single crystal spectra around the magic angles. The results are discussed in terms of the structure of the dinuclear unit and the bridges connecting CuII ions and compared with values reported for similar compounds.

A Novel Organotellurium Compound (RT-01) as a New Antileishmanial Agent

Leishmaniasis is a neglected disease and endemic in developing countries. A lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. The aim of this study was to investigate the effect of RT-01, an organotellurane compound presenting biological activities, in 2 experimental systems against Leishmania amazonensis. The in vitro system consisted of promastigotes and amastigotes forms of the parasite, and the in vivo system consisted of L. amazonensis infected BALB/c mice, an extremely susceptible mouse strain. The compound proved to be toxic against promastigotes and amastigotes. The study also showed that treatment with RT-01 produces an effect similar to that treatment with the reference antimonial drug, Glucantime, in L. amazonensis infected mice. The best results were obtained following RT-01 intralesional administration (720 mu g/kg/day); mice showed significant delay in the development of cutaneous lesions and decreased numbers of parasites obtained from the lesions. Significant differences in tissue pathology consisted mainly of no expressive accumulation of inflammatory cells and well-preserved structures in the skin tissue of RT-01-treated mice compared with expressive infiltration of infected cells replacing the skin tissue in lesions of untreated mice. These findings highlight the fact that the apparent potency of organotellurane compounds, together with their relatively simple structure, may represent a new avenue for the development of novel drugs to combat parasitic diseases.

Minimal Nielsen Root Classes and Roots of Liftings

Given a continuous map f : K -> M from a 2-dimensional CW complex into a closed surface, the Nielsen root number N(f) and the minimal number of roots mu(f) of f satisfy N(f) <= mu(f). But, there is a number mu(C)(f) associated to each Nielsen root class of f, and an important problem is to know when mu(f) = mu(C)(f)N(f). In addition to investigate this problem, we determine a relationship between mu(f) and mu((f) over tilde), when (f) over tilde f is a lifting of f through a covering space, and we find a connection between this problems, with which we answer several questions related to them when the range of the maps is the projective plane.

Isotropic and anisotropic spin-spin interactions and a quantum phase transition in a dinuclear Cu(II) compound

We report electron-paramagnetic resonance (EPR) studies at similar to 9.5 GHz (X band) and similar to 34 GHz (Q band) of powder and single-crystal samples of the compound Cu(2)[TzTs](4) [N-thiazol-2-yl-toluenesulfonamidatecopper(II)], C(40)H(36)Cu(2)N(8)O(8)S(8), having copper(II) ions in dinuclear units. Our data allow determining an antiferromagnetic interaction J(0)=(-113 +/- 1) cm(-1) (H(ex)=-J(0)S(1)center dot S(2)) between Cu(II) ions in the dinuclear unit and the anisotropic contributions to the spin-spin coupling matrix D (H(ani)=S(1)center dot D center dot S(2)), a traceless symmetric matrix with principal values D/4=(0.198 +/- 0.003) cm(-1) and E/4=(0.001 +/- 0.003) cm(-1) arising from magnetic dipole-dipole and anisotropic exchange couplings within the units. In addition, the single-crystal EPR measurements allow detecting and estimating very weak exchange couplings between neighbor dinuclear units, with an estimated magnitude parallel to J(')parallel to=(0.060 +/- 0.015) cm(-1). The interactions between a dinuclear unit and the ""environment"" of similar units in the structure of the compound produce a spin dynamics that averages out the intradinuclear dipolar interactions. This coupling with the environment leads to decoherence, a quantum phase transition that collapses the dipolar interaction when the isotropic exchange coupling with neighbor dinuclear units equals the magnitude of the intradinuclear dipolar coupling. Our EPR experiments provide a new procedure to follow the classical exchange-narrowing process as a shift and collapse of the line structure (not only as a change of the resonance width), which is described with general (but otherwise simple) theories of magnetic resonance. Using complementary procedures, our EPR measurements in powder and single-crystal samples allow measuring simultaneously three types of interactions differing by more than three orders of magnitude (between 113 cm(-1) and 0.060 cm(-1)).

Facies, delta(13)C, delta(15)N and C/N analyses in a late Quaternary compound estuarine fill, northern Brazil and relation to sea level

The present work integrates sedimentary facies, (14)C dating, delta(13)C, delta(15)N, and C/N with geologic and geomorphologic data available from literature. The aim was to characterize the depositional settings of a late Quaternary estuary in northeastern Marajo Island and analyze its evolution within the context of relative sea level fluctuations. The data derive from four continuous cores along a proximal-to-distal transect of a paleoestuary, previously recognized using remote sensing information. Fifteen sediment samples recorded ages ranging from 42,580 +/- 1430 to 3184 +/- 37 (14)C yr B.P. Fades analysis indicated fine- to coarse-grained sands with parallel lamination or cross stratification, massive or laminated muds and heterolithic deposits. delta(13)C (-28.1 parts per thousand to -19.7 parts per thousand, mean = -23.0 parts per thousand), delta(15)N (+ 14.8 parts per thousand to + 4.7 parts per thousand, mean = + 9.2 parts per thousand) and C/N (14.5 to 1.5, mean = 7.9) indicate mostly marine and freshwater phytoplankton sources for the organic matter. The results confirm a large late Quaternary paleoestuary in northeastern Marajo Island. The distribution of delta(13)C, delta(15)N, and C/N, together with fades associations, led to identify depositional settings related to fluvial channel, floodplain, tidal channel/tidal flat, central basin, tidal delta, and tidal inlet/sand barrier. These deposits are consistent with a wave-dominated estuary. Variations in stratigraphy and geochemistry are controlled by changes in relative sea level, revealing a main transgression from an undetermined time around 42,000 (14)C yr B.P. and 29,340 (+/- 200) (14)C yr B.P., which is synchronous to the overall drop in sea level after the last interglacial. Following this period, and probably until 9110 +/- 37 (14)C yr B.P., i.e., during a time interval encompassing two glacial episodes including the Last Glacial and the Younger Dryas, there was a pronounced drop in sea level, recorded by the development of a major erosional discontinuity due to valley re-incision. Sea level rose again until 5464 +/- 40 (14)C yr B.P, just before the main worldwide mid-Holocene transgressive peak. Mid to late Holocene coastal progradation ended the Marajo paleoestuarine history, and promoted the establishment of continental conditions throughout the island. The divergence comparing the Marajo sea level behavior with the eustatic curve allows hypothesizing that post-rifting tectonics along the Brazilian Equatorial margin influenced the sedimentary evolution of the studied paleoestuary. Considering that sedimentary facies in estuarine settings are highly variable both laterally and vertically, the present integration of facies with isotope and elemental analyses was crucial to provide a more precise interpretation of the Late Pleistocene and Holocene Marajo paleoestuary, and analyze its sea level history within the eustatic and tectonic context. (C) 2010 Elsevier B.V. All rights reserved.

The game inside the school: a representation of 5(th) graders physical education classes

Since the beginning of Physical Education entrance in the brazilin public schools, the game has been frequently used as content, and in the course of time that practice seems to be intensified. In spite of many approaches of different purposes to justify its pedagogic usefulness, the game has been used as an indiscriminate way due to the fascination that it provides to the students. The present study searches for a description and analysis of children`s (10-12 years old) attitudes behaviors in games, on Physical Education classes, inside a public school. The study was accomplished with the researcher also attending as a teacher (action research). For the accomplishment of the study 55 children were filmed in four different games, of different kinds (exposed, transformed, and spontaneous). The classes` description and analysis were focused in the attitude axis and it was defined four topics for the discussion: Conflicts, Respect of rules, Expressiveness, and Competitiveness. The relationship between the individual with the game and its culture were pointed as the main characteristics in the configuration of the ludicrous activity atmosphere. It was also possible to observe specific situations of this relationship, once the games were limited to the social games (Piaget category), in a school atmosphere where children have students roles. Due to the obtained results, the study proposes a reflexive practice in which the students notice their own attitudes and try to adapt the game to their needs and not he other way around. In this perspective, the teacher has an important mediator roll, once he will be responsible to point out the students` difficulties and promote discussions in favor to provide teamwork.

Comparative study of the biochemical changes and volatile compound formations during the production of novel whey-based kefir beverages and traditional milk kefir

Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8-8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir. (C) 2010 Elsevier Ltd. All rights reserved.

Spontaneous infiltrations of compound systems of Y(2)O(3), Sm(2)O(3), RE(2)O(3), Al(2)O(3) and AIN in SiC ceramics

Silicon carbide ceramics (SiC) are used in different applications in the engineering area due to the excellent properties, mainly in high temperatures. They are usually obtained by liquid-phase sintering enabling to form volatile products and, consequently, defects. The present work aims at studying the obtention of SiC ceramics by spontaneous infiltration using a eutectic composition of the Al(2)O(3)/Y(2)O(3), AIN/Y(2)O(3), Al(2)O(3)/Sm(2)O(3), AlN/Sm(2)O(3), Al(2)O(3)/RE(2)O(3) and AlN/RE(2)O(3) Systems. RE(2)O(3) is the concentrate of the rare-earth oxide obtained from Xenotime ore. Infiltration tests were carried out in argon atmosphere, graphite crucibles, in several temperatures near the melting point of each system, varying from 2.5 to 60 min. It was observed that Al(2)O(3)/Y(2)O(3), Al(2)O(3)/SM(2)O(3), AlN/SM(2)O(3) and Al(2)O(3)/RE(2)O(3) systems do not infiltrate appropriately and the AlN/Y(2)O(3) and AlN/RE(2)O(3) systems infiltrated spontaneously more than 20 mm; however, the first one presented a higher degree of infiltration, approximately 97%. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Toxicity and recalcitrant compound removal from bleaching pulp plant effluents by an integrated system: anaerobic packed-bed bioreactor and ozone

Effluents originated in cellulose pulp manufacturing processes are usually toxic and recalcitrant, specially the bleaching effluents, which exhibit high contents of aromatic compounds (e.g. residual lignin derivates). Although biological processes are normally used, their efficiency for the removal of toxic lignin derivates is low. The toxicity and recalcitrance of a bleached Kraft pulp mill were assessed through bioassays and ultraviolet absorption measurements, i.e. acid soluble lignin (ASL), UV(280), and specific ultraviolet absorption (SUVA), before and after treatment by an integrated system comprised of an anaerobic packed-bed bioreactor and oxidation step with ozone. Furthermore, adsorbable organic halides (AOX) were measured. The results demonstrated not only that the toxic recalcitrant compounds can be removed successfully using integrated system, but also the ultraviolet absorption measurements can be an interesting control-parameter in a wastewater treatment.

Electron theoretical investigation of the stability of the B2-TiFe compound

The metastable phase diagram of the BCC-based ordering equilibria in the Ti-Fe system has been calculated using a truncated cluster expansion, through the combination of FP-LAPW and cluster variation method (CVM) in the irregular tetrahedron cluster approximation. The results are compared with phenomenological CVM assessments of the system and suggest that the value for the experimental formation enthalpy of the B2-TiFe compound should be significantly more negative than the currently assessed value. (C) 2008 Elsevier B.V. All rights reserved.

Tunable Bragg filter using silicon compound films

In this work, we present the simulation, fabrication and characterization of a tunable Bragg filter employing amorphous dielectric films deposited by plasma enhanced chemical vapor deposition technique on a crystalline silicon substrate. The optical device was built using conventional microelectronic processes and consisted of fifteen periodic intervals of Si3N4 layers separated by air with appropriated thickness and lengths to produce transmittance attenuation peaks in the visible region. For this, previous simulations were realized based in the optical parameters of the dielectric film, which were extracted from ellipsometry and profilometry techniques. For the characterization of the optical interferential filter, a 633 nm monochromatic light was injected on the filter, and then the transmitted output light was collected and conducted to a detector through an optical waveguide made also of amorphous dielectric layers. Afterwards, the optical filter was mounted on a Peltier thermoelectric device in order to control the temperature of the optical device. When the temperature of filter changes, a refractive index variation is originated in the dielectric film due to the thermo-optic effect, producing a shift of attenuation peak, which can be well predicted by numerical simulations. This characteristic allows this device to be used as a thermo-optic sensor. (C) 2007 Elsevier B.V. All rights reserved.

Identification of a bioactive compound isolated from Brazilian propolis type 6

A prenylated benzophenone, hyperibone A, was isolated from the hexane fraction of Brazilian propolis type 6. Its structure was determined by spectral analysis including 2D NMR. This compound exhibited cytotoxic activity against HeLa tumor cells (IC(50) = 0.1756 mu M), strong antimicrobial activity (MIC range-0.73-6.6 mu g/mL; MBC range-2.92-106 mu g/mL) against Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Staphylococcus aureus, and Actinomyces naeslundii, and the results of its cytotoxic and antimicrobial activities were considered good. (C) 2009 Elsevier Ltd. All rights reserved.

Host-guest complexation of a nitroheterocyclic compound with cyclodextrins: a spectrofluorimetric and molecular modeling study

Nitroheterocyclic compounds (NC) were candidate drugs proposed for Chagas disease chemotherapy. In this study, we investigated the complexation of hydroxymethylnitrofurazone (NFOH), a potential antichagasic compound, with alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), Hydroxypropyl-beta-cyclodextrin (HP-beta-CD), Dimethyl-beta-cyclodextrin (DM-beta-CD) and gamma-cyclodextrin (gamma-CD) by fluorescence spectroscopy and molecular modeling studies. Hildebrand-Benesi equation was used to calculate the formation constants of NFOH with cyclodextrins based on the fluorescence differences in the CDs solution. The complexing capacity of NFOH with different CDs was compared through the results of association constant according to the following order: DM-beta-CD > beta-CD > alpha-CD > HP-beta-CD > gamma-CD. Molecular modeling studies give support for the experimental assignments, in favor of the formation of an inclusion complex between cyclodextrins with NFOH. This is an important study to investigate the effects of different kinds of cyclodextrins on the inclusion complex formation with NFOH and to better characterize a potential formulations to be used as therapeutic options for the oral treatment of Chagas disease.

Exploring weak interactions to assemble a nitrosyl-ruthenium compound able to release NO under visible light irradiation

This work reports oil a novel nitrosyl-ruthenium complex hearing the azanaphthalene ligand quinazoline (qui) ill its coordination sphere. The product crystallizes with ail additional quinazoline molecule, yielding the compound cis-[Ru(bpy)(2)(qui)NO](PF(6))(3).(qui). This feature leads to all absorption band at lambda(max) = 430 nm in CH(3)CN and lambda(max) = 420 nm in phosphate buffer, which promotes the photorelease of nitric oxide under visible light irradiation (lambda > 400 nm), in 1 ethanol: 1 water (v/v) mixture or under physiological pH. Both the intensity and energy of this transition are dependent on solvent and solution pH, suggesting that the transition has a charge transfer nature, and that the association of the second quinazoline molecule with the complex is driven by weak interactions, possibly of the pi-stacking type. (C) 2009 Elsevier Ltd. All rights reserved.