Female reproductive system of the sugarcane spittlebug Mahanarva fimbriolata (Auchenorrhyncha): Vitellogenesis dynamics and protein quantification

The present study aimed describing the ovaries of the sugarcane spittlebug Mahanarva fimbriolata which are meroistic telotrophic with nurse cells and oocytes located in the tropharium. SEM revealed paired ovaries located dorsolaterally around the intestine, and oocytes exhibiting shapes ranging from round (less developed) to elliptic (more developed), suggesting a simultaneous, although, asynchronous development. Based on histological data we classified the oocytes in stages from I to V. Stage I oocytes exhibit follicular epithelium with cubic and/or prismatic cells, fine cytoplasmic granules. Stage II oocytes present intercellular spaces in the follicular epithelium due to the incorporation of yolk elements from the hemolymph. Small granules are present in the periphery of oocytes while larger granules are observed in the center. Stage III oocytes are larger and intercellular spaces in the follicular epithelium are evident, as well as the interface between follicular epithelium and oocyte. Yolk granules of different sizes are present in the cytoplasm. During this stage, chorion deposition initiates. Stage IV oocytes exhibit squamous follicular cells and larger intercellular spaces when compared to those observed in the previous stage. The oocyte cytoplasm present granular and viscous yolk, the latter is the result of the breakdown of granules. Stage V oocytes exhibit a follicular epithelium almost completely degenerated, smaller quantities of granular yolk and large amounts of viscous yolk. Based on our findings we established the sequence of yolk deposition in M. fimbriolata oocyte as follows: proteins and lipids, which are first produced by endogenous processes in stages I and II oocytes. Exogenous incorporation begins in stage III. In stages I and II oocytes, lipids are also produced by follicular epithelial cells. The third element to be deposited is polysaccharides, mainly found as complexes. Therefore, the yolk present in the oocytes of this species consists of glycolipoproteins. Molecular weights of proteins present in M. fimbriolata oocytes ranged from 10 to 92 KDa, differently from vitellogenin, the most common protein present in insect oocytes, weighing approximately 180 KDa. (c) 2006 Elsevier Ltd. All rights reserved.

Kinetic parameters for thermal decomposition of supramolecular polymers derived from flunixin-meglumine adducts

Meglumine, (2R,3R,4R,5S)-6-methylaminohexane-1,2,3,4,5-pentol, is a carbohydrate derived from sorbitol in which the hydroxyl group in position one is replaced by a methylamine group. It forms binary adducts with substances having carboxyl groups, which have in common the presence of hydrogen bonding as the main force in the stabilization of these species. During melting, adducts of meglumine with flunixin (2-[[2-methyl-3-(trifluoromethyl)phenyl]amino]pyridine-3-carboxylic acid) polymerize or self-assemble in amorphous supramolecular structures with molecular weights around 2.0 x 10(5) kDa. DSC curves, in a first heating, show isomorphic transitions where the last one at 137 A degrees C for the flunixin-meglumine adduct originated the supramolecular amorphous polymers with glass transition around 49.5 A degrees C. The kinetic parameters for the thermal decomposition step of the polymers were determined by the Capela-Ribeiro non-linear isoconversional method. From data for the TG curves in nitrogen atmosphere and heating rates of 5, 10, 15, and 20 A degrees C min(-1), the E (alpha) and B (alpha) terms could be determined and, consequently, the pre-exponential factor, A(alpha), as well as the kinetic model, g(alpha).

Quadro seroproteico como auxílio diagnóstico na anemia hemolítica imunomediada em cães

No presente protocolo experimental, determinaram-se os proteinogramas séricos, por intermédio da eletroforese em gel de poliacrilamida contendo duodecil sulfato de sódio (SDS-PAGE), de 120 cães com raças e idades variadas e atendidos junto ao Hospital Veterinário Governador Laudo Natel da FCAV/Unesp, com o objetivo principal de comparar diferentes frações seroproteicas em estados anêmicos regenerativos, arregenerativos, imunomediados primários e secundários. Os referidos animais foram distribuídos em cinco grupos experimentais: grupo 1: 20 cães de controle; grupo 2: 28 cães com anemia regenerativa não imune; grupo 3: 27 cães com anemia arregenerativa não imune; grupo 4: 10 cães com anemia hemolítica imunomediada primária; grupo 5: 35 cães com anemia hemolítica imunomediada secundária. A técnica SDS-PAGE permitiu o fracionamento de 24 proteínas, cujos pesos moleculares (PM) variaram de 18.000 a 165.000 daltons (Da). Os cães com AHIM primária e secundária apresentaram 24 frações proteicas em seus traçados eletroforéticos, enquanto que cães de controle (1) e portadores de anemia regenerativa (2) e arregenerativa (3) de natureza não imune apresentaram 23 frações de proteínas, cuja proteína de peso molecular 68.000Da não foi encontrada. Dessa forma, 23 frações proteicas foram detectadas e revelaram-se comuns aos proteinogramas dos cães de controle e daqueles dos quatro grupos experimentais. Destas, identificaram-se nominalmente 11 frações proteicas, e as demais foram estudadas com base nos seus respectivos pesos moleculares. em relação aos cães de controle, os anêmicos (grupos 2, 3, 4 e 5) apresentaram maiores concentrações de transferrina sérica e entre estes os animais portadores da AHIM primária. Todos os cães anêmicos apresentaram teores séricos de haptoglobina e fosforilase significativamente maiores que os controles, enquanto que a concentração sérica de ceruloplasmina foi significativamente maior nestes. Tais achados analisados em conjunto agregam informações adicionais úteis à elucidação das AHIMs em cães.

Small-angle X-ray scattering study of sol-gel-derived siloxane-PEG and siloxane-PPG hybrid materials

Hybrid organic-inorganic two-phase nanocomposites of siloxane-poly(ethylene glycol) (SiO3/2-PEG) and siloxane-poly(propylene glycol) (SiO3/2-PPG) have been obtained by the sol-gel process. In these composites, nanometric siloxane heterogeneities are embedded in a polymeric matrix with covalent bonds in the interfaces. The structure of these materials was investigated in samples with different molecular weights of the polymer using the smalt-angle X-ray scattering (SAXS) technique. The SAXS spectra exhibit a well-defined peak that was attributed to the existence of a strong spatial correlation of siloxane clusters. LiClO4-doped siloxane-PEG and siloxane-PPG hybrids, which exhibit good ionic conduction properties, have also been studied as a function of the lithium concentration [O]/[Li], O being the oxygens of ether type. SAXS results allowed us to establish a structural model for these materials for different basic compositions and a varying [Li] content. The conclusion is consistent with that deduced from ionic conductivity measurements that exhibit a maximum for [O]/[Li] =15.

Siloxane-polypropyleneoxide hybrid ormolytes: structure-ionic conductivity relationships

Siloxane-polypropyleneoxide (PPO) hybrids doped with sodium perchlorate (NaClO4) obtained by the sol-gel process were prepared with two PPO molecular weights (2000 and 4000 g/mol) and two sodium concentrations such as [O]/[Na] = 4 and 15 (O being the ether-type oxygen of PPO chains). The structure of these hybrids was investigated by Na-23 nuclear magnetic resonance (NMR) and X-ray absorption spectroscopy at the sodium K-edge (1071.8 eV) whereas complex impedance spectroscopy was used to determine their ionic conductivity. Three sodium sites were determined by NMR. The conjunction of NMR and X-ray absorption results allows us to identify one site in which Na is in a NaCl structure, a second one in which Na is in contact with perchlorate anions. The third site is attributed to mobile sodium species in interaction with the polymeric chain. The relative proportion of the different sites in the materials determines the ionic conductivity of the materials at room temperature: the largest ionic conductivity is 8.9 x 10(-6) Omega(-1) cm(-1) and is observed on the material with the larger amount (at least 85%) of sites in which sodium interacts with the polymer. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Energy-transfer mechanisms and emission quantum yields in Eu3+-based siloxane-poly(oxyethylene) nanohybrids

We report the energy-transfer mechanisms and emission quantum yield measurements of sol-gel-derived Eu3+-based nanohybrids. The matrix of these materials, classified as diureasils and termed U(2000) and U(600), includes urea cross-links between a siliceous backbone and polyether-based segments of two molecular weights, 2000 and 600, respectively. These materials are full-color emitters in which the Eu3+ (5)Do --> F-7(0-4) lines merge with the broad green-blue emission of the nanoscopic matrix's backbone. The excitation spectra show the presence of a large broad band (similar to 27000-29000 cm(-1)) undoubtedly assigned to a ligand-to-metal charge-transfer state. Emission quantum yields range from 2% to 13.0% depending on the polymer molecular weight and Eu3+ concentration. Energy transfer between the hybrid hosts and the cations arises from two different and independent processes: the charge-transfer band and energy transfer from the hybrid's emitting centers. The activation of the latter mechanisms induces a decrease in the emission quantum yields (relative to undoped nanohybrids) and permits a fine-tuning of the emission chromaticity across the Comission Internacionalle d'Eclairage diagram, e.g., (x, y) color coordinates from (0.21, 0.24) to (0.39, 0.36). Moreover, that activation depends noticeably on the ion local coordination. For the diureasils with longer polymer chains, energy transfer occurs as the Eu3+ coordination involves the carbonyl-type oxygen atoms of the urea bridges, which are located near the hybrid's host emitting centers. on the contrary, in the U(600)-based diureasils, the Eu3+ ions are coordinated to the polymer chains, and therefore, the distance between the hybrid's emitting centers and the metal ions is large enough to allow efficient energy-transfer mechanisms.

ISOLATION AND IN-VITRO HYDROLYSIS OF GLOBULIN G1 FROM LENTILS (LENS-CULINARIS, MEDIK)

The major globulin fraction from lentil seeds was investigated with respect td in vitro hydrolysis by trypsin and chymotrypsin. Globulin was isolated by a NaCl-ascorbate extraction procedure and purified by DEAE-cellulose chromatography and gelfiltration chromatography on Sepharose CL-6B. The purity and identification of the protein were performed by PAGE. The native globulin, with a molecular weight of 375 kD, was resolved by SDS-PAGE into twelve polypeptides with molecular weights ranging from 61 to 14.5 kD. Native and heated globulin GI was hydrolyzed with trypsin and chymotrypsin. SDS-PAGE indicated that native globulin was more resistant to digestion than heated protein. Amino acid analysis of the major globulin revealed that glutamic acid was present in the largest concentration, followed by aspartic acid, arginine and leucine. As is also the case for other legumin-like globulins, lentil GI was deficient in sulfur-containing amino acids.

Electrophoretic variants of intracellular catalase of different Candida species

Intracellular and extracellular catalases of different species of Candida were investigated using different culture media. All the Candida strains produced intracellular catalase, whose enzymatic activity was detected by non-denaturating polyacrylamide gradient (4-30%) gel electrophoresis. The cell extracts presented a major 230 kDa catalase band and in some strains variants of catalase with different molecular weights were detected. Candida catalase activity was not affected by heating at 50degreesC and incubation with beta-mercaptoethanol, but treatment with sodium dodecyl sulphate inhibited or reduced enzymatic activity. Extracellular enzyme activity was not detected in any of the culture filtrate extracts tested.

Allergenic extracts from Metarhizium anisopliae: Obtainment and characterization

Metarhizium anisopliae is used as a biopesticide for insects that damage agricultural plantations like sugar cane and forage plants. In a previous study the sensitization to this fungus of asthmatic patients coming from sugar cane areas was showed. The aims of this work were: to compare crude extracts obtained with Tris-HCl and Coca liquid from several growth phases of M. anisopliae concerning the total content of proteins and their electrophoretic analysis profile; to evaluate in vivo allergic sensitization in Balb/c mice and allergic patients from a sugar cane area, and to characterize the allergenic fractions in the sera of patients positive for the prick test by means of Western-blotting. The extract obtained with Coca liquid on the 16(th) day was the one that presented the greatest number of proteic fractions, including all those present in the other extracts. Twelve fractions were verified in this extract with approximate molecular weights from 94 to 14 kDa. The allergenicity of the extract obtained on the 16(th) day was proven by the production of IgE antibodies in Balb/c mice, with titres of 200. Prick tests carried out with the extract of the 16(th) day in 79 atopic individuals (from sugar cane area), 35 atopic individuals (from urban area) and 11 non- atopic individuals showed respective positivity of 29%, 9% and 0%. The allergenic characterization in vitro was performed by means of Western blotting, and the fractions that reacted with the positive individuals' sera were those of approximate molecular weights of 67 kDa (95%); 20 kDa (55%); 94 kDa (36%); 34 and 36 kDa (23%); 43 and 48 kDa (14%): 16 kDa (9%) and 54kDa (5%). It was concluded that the crude allergenic extract, obtained with Coca liquid from the 16(th) day growth of Metarhizium anisopliae, contains allergenic fractions and can be used in diagnostic screening tests.

Structure and electrical properties of potassium-doped siloxane-poly(oxypropylene) ormolytes

The structure and the ionic conduction properties of siloxane-poly(oxypropylene) (PPO) hybrids doped with different potassium salts (KCF3SO3, KI, KClO4 and KNO2) are reported for two polymer molecular weights (300 and 4000 g/mol), labelled PPO300 and PPO4000, respectively. The doping concentration, related to the concentration of the ether type oxygen of the PPO chain, is the same whatever the salt and verifies [O]/[K] = 20. Ionic room temperature conductivity shows the highest value for the KCF3SO3 doped PPO4000 hybrid (4 x 10(-7)Omega(-1).cm(-1)). The structure of these hybrids was investigated by X-ray powder diffraction (XRPD) and X-ray absorption spectroscopy (EXAFS and XANES) at the potassium K-edge (3607 eV). XRPD results show that the hybrid matrix is always amorphous and the formation of secondary potassium phases is observed for all the samples, except for the KCF3SO3 doped PPO4000 hybrid. EXAFS results evidence a good correlation between the ionic conductivity and the presence of oxygen atoms as first neighbours around potassium.

Interface morphology snapshots of vertically segregated thin films of semiconducting polymer/polystyrene blends

We present atomic force microscopic images of the interphase morphology of vertically segregated thin films spin coated from two-component mixtures of poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) and polystyrene (PS). We investigate the mechanism leading to the formation of wetting layers and lateral structures during spin coating using different PS molecular weights, solvents and blend compositions. Spinodal decomposition competes with the formation of surface enrichment layers. The spinodal wavelength as a function of PS molecular weight follows a power-law similar to bulk-like spinodal decomposition. Our experimental results indicate that length scales of interface topographical features can be adjusted from the nanometer to micrometer range. The importance of controlled arrangement of semiconducting polymers in thin film geometries for organic optoelectronic device applications is discussed. (c) 2007 Elsevier Ltd. All rights reserved.

Titanium and zirconium complexes containing sterically hindered hydrotris(pyrazolyl)borate ligands: synthesis, structural characterization, and ethylene polymerization studies

The synthesis, characterization and ethylene polymerization behavior of a set of Tp'MCl3 complexes (4, M = Ti, Tp' HB(3-neopentyl-pyrazolyl)(3)(-) (Tp(NP)); 5, M = Ti, Tp'= HB(3-tert-butyl-pyrazolyl)(3)(-) (Tp(tBu)); 6, M = Ti, Tp' = HB(3-phenyl-pyrazolyl)(3)(-) (Tp(Ph)); 7, M = Zr, Tp' = HB(3-phenyl-pyrazolyl)(3)(-) (Tp(ph)); 8, M = Zr, Tp' = HB(3-tert-butyl-pyrazolyl)(3)(-) (Tp(tBu))) is described. Treatment of these tris(pyrazolyl)borate Group IV compounds with methylalumoxane (MAO) generates active catalysts for ethylene polymerization. For the polymerization reactions performed in toluene at 60 degreesC and 3 atm of ethylene pressure, the activities varied between 1.3 and 5.1 X 10(3) g of PE/mol[M](.)h. The highest activity is reached using more sterically open catalyst precursor 4. The viscosity-average molecular weights ((M-v) over bar) of the PE's produced with these catalyst precursors varying from 3.57 to 20.23 x 10(5) gmol(-1) with melting temperatures in the range of 127-134 degreesC. Further polymerization studies employing 7 varying Al/Zr molar ratio and temperature of polymerization showed that the activity as well as the polymer properties are dependent on these parameters. In that case, higher activity was attained at 60 degreesC. The viscosity-average molecular weights of the polyethylene's decreases with increasing AI/Zr molar ratio. (C) 2003 Elsevier B.V. All rights reserved.

Synthesis and properties of branched polyethylene/high-density polyethylene blends using a homogeneous binary catalyst system composed of early and late transition metal complexes

Branched polyethylene/high-density polyethylene blends (BPE/HDPE) with a wide range of molecular weights, melt flow indexes (MFI), and intrinsic viscosity were prepared using the homogeneous binary catalyst system composed by Ni(alpha-diimine)Cl-2 (1) (alpha-diimine = 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediimine) and {Tp(Ms*)} TiCl3 (2) (Tp(Ms*)=hydridobis(3-mesitylpyrazol-1-yl)(5-mesityl-pyrazol-1-yl)) activated with MAO and/or TIBA in hexane at two different polymerization temperatures (30 and 55 degreesC) and by varying the nickel loading molar fraction (x(Ni)). At all Temperatures, a non-linear correlation between the x(Ni) and the productivity was observed, suggesting the occurrence of a synergistic effect between the nickel and the titanium catalyst precursors, which is more pronounced at 55 degreesC. The molecular weight of the BPE/HDPE blends considerably decreases with increasing Al/M molar ratio. The melt flow indexes (MFI) and intrinsic viscosities (eta) are strongly affected by x(Ni), but the melting temperatures are nearly constant, 132 +/- 3 degreesC. Dynamic mechanical thermal analysis (DMTA) shows the formation of different polymeric materials where the stiffness vanes according, to the x(Ni) and temperature used in the polymerization reaction. The surface morphology of the BPE/HDPE blends studied by scanning electron microscopy (SEM) revealed a low miscibility between the PE phases resulting in the formation of a sandwich structure after etching with o-xylene.

Essential oil from leaves of Cryptocarya mandioccana Meisner (Lauraceae): Composition and intraspecific chemical variability

The composition of the essential oil from leaves of Cryptocarya mandioccana has been determined by chromatographic fractionation and GC-FID, GC-MS and C-13 NMR analyses, yielding the identification of 64 compounds with predominance of isomeric sesquiterpenes with molecular weights of 204. The main components of the oil obtained by hydrodistillation were beta-caryophyllene, spathulenol, caryophyllene oxide, delta-cadinene, germacrene D, benzaldehyde and bicyclogermacrene. However, the oil obtained by steam distillation contained higher levels of sesquiterpene hydrocarbons, with predominance of P-caryophyllene (C), germacrene D (G) and bicyclogermacrene (B), and was considered to be more representative of the composition of the oil in its natural state. The intraspecific chemical variability of the essential oil obtained by steam distillation was evaluated within populations of trees growing at three separate locations in the state of São Paulo, Brazil. Three distinct chemical groups could be characterised due to differences in the relative percentages of the three main sesquiterpenes from essential oil: CGB [relative contents of C (14-34%), G (5-28%), B (8-15%)], BCG [B (17-34%), C (9-24%), G (12-25%)] and GCB [G (22-42%), C (4-17%), B (7-15%)]. Individuals from groups CGB and BCG were found to be more frequent at south locations while group GCB is predominant in north location. (c) 2006 Elsevier Ltd. All rights reserved.

Polymerization of ethylene by the tris(pyrazolyl)borate titanium(IV) compound immobilized on MAO-modified silicas

The immobilization of soluble catalyst {Tp(Ms)}TiCl3 (Tp(Ms*)HB(3-mesityl-pyrazolyl)(2)(5-mesityl-pyrazolyl)(-)) on silica and MAO-modified silicas containing 4.0, 8.0 and 23.0 wt.% Al/SiO2 yields active supported catalysts for ethylene polymerization. Among the supported catalysts studied by XRF spectroscopy, higher titanium content was obtained using MAO-modified silica containing 8.0 wt.% Al/SiO2 as support. For the ethylene polymerization reactions carried out in hexane at 60degreesC using a combination of triisobutylaluminum (TiBA) and methylaluminoxane (MAO) (1:1), the activities varied between 24.4 and 113.5 kg of PE/mol [Ti] h. The highest activity is reached using MAO-modified silica containing 4.0 wt.% Al/SiO2 as support. The viscosity-average molecular weights ((M) over bar (v)) of the PE's produced with the supported catalysts varying from 1.44 to 9.94 x 10(5) g/mol with melting temperatures in the range of 125-140degreesC. The use of other Lewis acid cocatalysts, including TiBA, diethylaluminium chloride (DEAC), and trimethylaluminum (TMA) resulted also in the formation of active catalysts for ethylene polymerization. However, the activities are lower than that one using a combination of TiBA and MAO. The viscosity-average molecular weights (R,) of PE's are influenced by varying the cocatalysts as well as the Al/Ti molar ratio. The supported catalyst generated in situ under ethylene atmosphere is roughly four times more active than supported one containing 4.0 wt.% Al/SiO2. (C) 2003 Elsevier B.V. All rights reserved.