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Sample records for monomeric primary amido

  1. Reactivity studies on [Cp'FeI]2: monomeric amido, phenoxo, and alkyl complexes.

    Science.gov (United States)

    Walter, Marc D; White, Peter S

    2012-11-05

    A series of monomeric mono(cyclopentadienyl) iron amido, phenoxo, and alkyl complexes were synthesized, and their structure and reactivity are presented. The iron(II) centers in these 14VE one-legged piano stool complexes are high spin (S = 2) in solid state and solution independent of solvent. The silylamide compound [Cp'FeN(SiMe(3))(2)] (2a, Cp' = 1,2,4-(Me(3)C)(3)C(5)H(2)) is an excellent starting material for the reaction with more acidic substrates such as phenols. Sterically encumbered phenols 2,6-(Me(3)C)(2)(4-R)C(6)H(2)OH (R = H, Me, and tBu) were investigated. In all cases monomeric iron phenoxo half-sandwich complexes [Cp'FeOR'] (4-R) are initially formed. Rearrangement of 4-R to the diamagnetic oxocyclohexadienyl complex [Cp'Fe(η(5)-O═C(6)H(2)R'(2)R")] (5-R) is observed for 2,6-(Me(3)C)(2)(4-R)C(6)H(2)OH (R = H and Me) and the Gibbs free enthalpy of activation (ΔG(‡)) was determined. In contrast this rearrangement is inhibited when the 4-position is blocked by a tBu group. Removing the steric bulk from the 2,6-positions leads to the formation of a μ-phenoxo dimer, [Cp'Fe(μ-OC(6)H(3)tBu(2)-3,5)](2) (5). Density functional theory (DFT) was used to further elucidate the structure-reactivity relationship in these molecules. The one-legged piano stool anilido complex [Cp'Fe(NHC(6)H(2)tBu(3)-2,4,6)] (7) is not accessible via acid-base reaction between 2a and H(2)NC(6)H(2)tBu(3)-2,4,6, but can be prepared by conventional salt metathesis reaction from [Cp'FeI](2) and [Li(NHC(6)H(2)tBu(3)-2,4,6)(OEt(2))](2). In contrast, reaction of 2a with Ph(2)NH yields the bimetallic [Cp'Fe(N,C-κ(1),η(5)-C(6)H(5)NPh)Fe(N-κ(1)-NPh(2))Cp'] (8) which combines two iron centers in the same oxidation state (+2), but different spin-states (S = 0 and S = 2) which is reflected in very different Cp(cent)-Fe distances of 1.68 and 2.04 Å, respectively. A monomeric iron alkyl half-sandwich complex [Cp'FeCH(SiMe(3))(2)] (9) was prepared that exhibits no reactivity toward H(2), C

  2. Amido resistente obtido a partir de amido de leguminosas e de seus hidrolisados

    OpenAIRE

    2009-01-01

    O amido resistente (AR) é a fração do amido que não sofre a ação das enzimas digestivas, apresentando comportamento semelhante ao da fibra dietética. O objetivo do presente trabalho foi avaliar o teor e as características dos AR obtidos a partir dos amidos de ervilha e de grão-de-bico por diferentes processos de redução de massa molecular. Os amidos naturais ou gelatinizados foram submetidos a processos de hidrólise ácida (HCl 2 M por 2,5 h) ou enzimática (pululanase, 40 U/g por 10 h) previam...

  3. Amido resistente em diversas fontes não convencionais de amido

    Directory of Open Access Journals (Sweden)

    C. Fontinha

    2016-02-01

    Full Text Available Amido resistente (AR é aquele que não é digerido no intestino delgado, conduzindo a efeitos benéficos para a saúde, tal como a fibra dietética faz. Procedeu-se à determinação do AR em farinhas e amidos extraídos de duas variedades de castanha (Castanea sativa Mill, Longal e Martainha, da bolota de azinheira (Quercus rotundifolia e da glande do sobreiro (Quercus suber. As farinhas foram obtidas por moenda dos frutos após secagem a diferentes temperaturas, 40º C, 50º C, 60ºC e 70ºC. Posteriormente, procedeu-se ao isolamento dos amidos das farinhas, através da aplicação de dois métodos de extracção: um físico-químico e outro enzimático. Verificou-se que os teores de AR mais elevados foram os apresentados pelas farinhas dos frutos secos a 60ºC, sendo de 46,8%, 36,5%, 39,9% e 43,9%, respectivamente para as castanhas das variedades Longal e Martainha, para a bolota e para a glande. O método de extracção que apresentou valores mais elevados de AR para os amidos extraídos dos diferentes materiais foi o método físico-químico. Tudo indica que a secagem dos frutos a 60ºC e a aplicação do método de extracção do amido pelo processo físico-químico nas farinhas dos frutos secos a esta temperatura são aqueles que melhor preservam a estrutura dos amidos.

  4. Amido de milho e mandioca na produção de maltodextrinas

    OpenAIRE

    Moore,Geovana Rocha Plácido

    2001-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias Amido de mandioca e de milho foram estudados quanto à produção de maltodextrinas, visando demonstrar que a mandioca, cultivada em abundância no Brasil, pode representar uma matéria-prima tão importante quanto o milho para a produção deste amido modificado. Os amidos foram caracterizados quanto ao conteúdo de amilose, tendo encontrado 24,26% de amilose no amido de milho e 16,67% no amido de mandioc...

  5. Poly(amido-amine)-based hydrogels with tailored mechanical properties and degradation rates for tissue engineering.

    Science.gov (United States)

    Martello, Federico; Tocchio, Alessandro; Tamplenizza, Margherita; Gerges, Irini; Pistis, Valentina; Recenti, Rossella; Bortolin, Monica; Del Fabbro, Massimo; Argentiere, Simona; Milani, Paolo; Lenardi, Cristina

    2014-03-01

    Poly(amido-amine) (PAA) hydrogels containing the 2,2-bisacrylamidoacetic acid-4-amminobutyl guanidine monomeric unit have a known ability to enhance cellular adhesion by interacting with the arginin-glycin-aspartic acid (RGD)-binding αVβ3 integrin, expressed by a wide number of cell types. Scientific interest in this class of materials has traditionally been hampered by their poor mechanical properties and restricted range of degradation rate. Here we present the design of novel biocompatible, RGD-mimic PAA-based hydrogels with wide and tunable degradation rates as well as improved mechanical and biological properties for biomedical applications. This is achieved by radical polymerization of acrylamide-terminated PAA oligomers in both the presence and absence of 2-hydroxyethylmethacrylate. The degradation rate is found to be precisely tunable by adjusting the PAA oligomer molecular weight and acrylic co-monomer concentration in the starting reaction mixture. Cell adhesion and proliferation tests on Madin-Darby canine kidney epithelial cells show that PAA-based hydrogels have the capacity to promote cell adhesion up to 200% compared to the control. Mechanical tests show higher compressive strength of acrylic chain containing hydrogels compared to traditional PAA hydrogels.

  6. Reducible poly(amido ethylenimine) directed to enhance RNA interference

    NARCIS (Netherlands)

    Jeong, Jo Hoon; Christensen, L.; Christensen, Lane V.; Yockman, James W.; Zhong, Zhiyuan; Engbersen, Johannes F.J.; Kim, Won Jong; Feijen, Jan; Kim, Sung Wan

    2007-01-01

    Designing synthetic macromolecular vehicles with high transfection efficiency and low cytotoxicity has been a major interest in the development of non-viral gene carriers. A reducible poly(amido ethylenimine) (SS-PAEI) synthesized by addition copolymerization of triethylenetetramine and cystamine

  7. Preparation of mesoporous aluminophosphate usingpoly(amido amine) as template

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaofeng; LIN Shen; CHEN Xinqing; CHEN Jiebo; YANG Liuyi; LUO Minghong

    2007-01-01

    Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier transform infrared spectrometer(FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods.Results show that the title compound exhibits a typical mesoporous structure with the average pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.

  8. Synthesis, antimicrobial and anticancer activities of amido sulfonamido methane linked bis heterocycles

    Directory of Open Access Journals (Sweden)

    Chokkappagari Premakumari

    2014-09-01

    Full Text Available A new class of amido sulfonamido methane linked bis heterocycles- bis-oxazoles, thiazoles and imidazoles were prepared and screened for antimicrobial and anticancer activities. The chloro substituted amido sulfonamido bisimidazole exhibited excellent antimicrobial activity and also it was the most potent compound on lung, colon and prostate cancer cell lines.

  9. Amido a partir de bambu Starch from bamboo culm

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    Anísio Azzini

    1984-01-01

    Full Text Available Em colmos de bambu da espécie tida como Guadua flabellata, determinaram-se os teores de amido e das frações fibrosa, parenquimatosa e solúvel em água. O comprimento e o diâmetro dos colmos processados foram também determinados. Os resultados mostraram que o teor médio de amido extraído foi 8,53% (base seca, representando cerca de 59% da fração solúvel em água e 32% do total de amido existente no colmo. Os teores médios das frações fibrosa, parenquimatosa e solúvel em água foram, respectivamente, 61,76%, 23,05% e 15,18%, Quanto às dimensões do colmo, a espécie em estudo pode ser considerada de porte mediano, em comparação com as espécies mais difundidas em nossas condições.In bamboo culms of the species reported as Guadua flabellata were determined the contents of starch, fibrous fraction, parenchymatous fractions and water soluble fractions. The height and diameter of the bamboo culms were also determined. The results showed that the average content of extracted starch was 8.53% (over dry material. This content corresponds to about 59% of the fractions and 32% of the total starch present in the bamboo culm. The fibrous fractions and water soluble fractions were, respectively 61.76% and 23.05%. Regarding to culm dimensions, this species can be considered as a middle sized culm.

  10. Intercalating quaternary nicotinamide-based poly(amido amine)s for gene delivery.

    Science.gov (United States)

    van der Aa, L J; Vader, P; Storm, G; Schiffelers, R M; Engbersen, J F J

    2014-12-10

    In the development of potent polymeric gene carriers for gene therapy, a good interaction between the polymer and the nucleotide is indispensable to form small and stable polyplexes. Polymers with relatively high cationic charge density are frequently used to provide these interactions, but high cationic charge is usually associated with severe cytotoxicity. In this study an alternative, nucleotide specific binding interaction based on intercalation was investigated to improve polymer/pDNA complex formation. For this purpose bioreducible poly(amido amine) copolymers (p(CBA-ABOL/Nic)) were synthesized with different degrees of intercalating quaternary nicotinamide (Nic) groups and amide-substituted derivatives in their side chains. The quaternary nicotinamide group was chosen as intercalating moiety because this group is part of the naturally occurring NAD+ coenzyme and is therefore expected to be non-toxic and non-carcinogenic. The presence of the quaternary nicotinamide moieties in the poly(amido amine) copolymers showed to effectively promote self-assembled polyplex formation already at low polymer/DNA ratios and results in decreased polyplex size and increased stability of the polyplexes. Furthermore, in contrast to the primary amine functionalized analogs the quaternary nicotinamide polymers showed to be non-hemolytic, indicating their compatibility with cell membranes. Polymers with 25% of Nic in the side chains induced GFP expressions of about 4-5 times that of linear PEI, which is comparable with p(CBA-ABOL), the parent PAA without Nic, but at a two- to fourfold lower required polymer dose. N-phenylation of the nicotinamide functionality even further reduces the required polymer dose to form stable polyplexes, which is a major improvement for these kinds of cationic polymers. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Estudo do amido de farinhas comerciais comestíveis

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    Bianca N. B. Lima

    Full Text Available O amido em quatro tipos de farinhas comerciais para uso doméstico em preparações culinárias foi caracterizado pelas técnicas de espectroscopia de absorção na região do infravermelho com Transformada de Fourier (FTIR, difração de raios X (DRX, análise termogravimétrica e ressonância magnética nuclear de baixo campo, por meio da determinação do tempo de relaxação spin-rede do núcleo de hidrogênio (T1H.

  12. Estudo do amido de farinhas comerciais comestíveis

    OpenAIRE

    2012-01-01

    O amido em quatro tipos de farinhas comerciais para uso doméstico em preparações culinárias foi caracterizado pelas técnicas de espectroscopia de absorção na região do infravermelho com Transformada de Fourier (FTIR), difração de raios X (DRX), análise termogravimétrica e ressonância magnética nuclear de baixo campo, por meio da determinação do tempo de relaxação spin-rede do núcleo de hidrogênio (T1H).

  13. Size separation of analytes using monomeric surfactants

    Science.gov (United States)

    Yeung, Edward S.; Wei, Wei

    2005-04-12

    A sieving medium for use in the separation of analytes in a sample containing at least one such analyte comprises a monomeric non-ionic surfactant of the of the general formula, B-A, wherein A is a hydrophilic moiety and B is a hydrophobic moiety, present in a solvent at a concentration forming a self-assembled micelle configuration under selected conditions and having an aggregation number providing an equivalent weight capable of effecting the size separation of the sample solution so as to resolve a target analyte(s) in a solution containing the same, the size separation taking place in a chromatography or electrophoresis separation system.

  14. Monomeric Friction Coefficient of Metalnanodispersible Polymeric Systems

    Directory of Open Access Journals (Sweden)

    B.B. Kolupayev

    2016-12-01

    Full Text Available Influence of a nanodispersible metal excipient in number of 0    5,0 vol.% Cu for the size of a monomeric friction coefficient of polyvinylchloride (PVC systems in temperature range 298  Т  (Tg + 10 K is investigated. It is shown that various types of coordination movements of building blocks are described by a friction coefficient which serves as a measure of influence of external fields and ingredients on viscoelastic behavior of a composite. The analysis of processes of a relaxation on the basis of the theory of flexible chains taking into account power and entropic factors is carried out.

  15. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J;

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected to...... immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation.......An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...

  16. Computational design and characterization of a monomeric helical dinuclear metalloprotein.

    Science.gov (United States)

    Calhoun, Jennifer R; Kono, Hidetoshi; Lahr, Steven; Wang, Wei; DeGrado, William F; Saven, Jeffery G

    2003-12-12

    The de novo design of di-iron proteins is an important step towards understanding the diversity of function among this complex family of metalloenzymes. Previous designs of due ferro (DF) proteins have resulted in tetrameric and dimeric four-helix bundles having crystallographically well-defined structures and active-site geometries. Here, the design and characterization of DFsc, a 114 residue monomeric four-helix bundle, is presented. The backbone was modeled using previous oligomeric structures and appropriate inter-helical turns. The identities of 26 residues were predetermined, including the primary and secondary ligands in the active site, residues involved in active site accessibility, and the gamma beta gamma beta turn between helices 2 and 3. The remaining 88 amino acid residues were determined using statistical computer aided design, which is based upon a recent statistical theory of protein sequences. Rather than sampling sequences, the theory directly provides the site-specific amino acid probabilities, which are then used to guide sequence design. The resulting sequence (DFsc) expresses well in Escherichia coli and is highly soluble. Sedimentation studies confirm that the protein is monomeric in solution. Circular dichroism spectra are consistent with the helical content of the target structure. The protein is structured in both the apo and the holo forms, with the metal-bound form exhibiting increased stability. DFsc stoichiometrically binds a variety of divalent metal ions, including Zn(II), Co(II), Fe(II), and Mn(II), with micromolar affinities. 15N HSQC NMR spectra of both the apo and Zn(II) proteins reveal excellent dispersion with evidence of a significant structural change upon metal binding. DFsc is then a realization of complete de novo design, where backbone structure, activity, and sequence are specified in the design process.

  17. On the quantitative Amido Black B staining of protein spots in agar gel at low local protein concentrations

    NARCIS (Netherlands)

    Jansen, M.T.

    1962-01-01

    Protein spots in agar gel of identical protein content but different in surface area are found to bind different amounts of dye upon staining with Amido Black B. The lower the protein concentration within the agar gel, the more the Amido Black B content of the spot falls short of the value expected

  18. Cytospectrophotometric evaluation of Amido Black staining of proteins in nervous tissue cells.

    Science.gov (United States)

    Klenikova, V A; Pevzner, L Z

    1979-11-01

    Cytospectrophotometry of agar films soaked with serum albumin and of nervous tissue cells has shown that the histochemical colour reaction of proteins with Amido Black 10 B obeys Beer's law and that the spectral characteristics of this reaction are not significantly changed after fixation and histological procedure of nervous tissue. In cats, after in situ electrostimulation, and in rats, after anticipation stress, quantitative changes in the total protein content per cell were revealed in nerve and glial cells of cat sympathetic ganglion and rat spinal cord with the aid of cytospectrophotometry of Amido Black-stained sections. Staining with Amido Black 10B is recommended for cytospectrophotometric determinations of total protein and of separate protein fractions in nervous system cells.

  19. A New Asymmetric α-Amido-hydroxyalkylation Mediated by SmI2

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiao; FENG Chen-Guo; HUNG Pei-Qiang

    2004-01-01

    Polyhydroxylated indolizidine alkaloids, such as castanospermine (Ⅰ) and swainsonine (H)are of longstanding interest due to their powerful glycosidase inhibitory activity. Asymmetric hydroxyatkylation via α-amido carbanions to form C-C bands would provide a convenient approach to these compounds.In continuation of our efforts in developing asyrmmetric o-amido-hydroxyalkylation method,1 we report a new SmI2 mediated flexible asymmetric α-amido-hydroxyalkylation method. Starting from the known (S)-3-hydroxy-2-pyrrolidinone 1,2 sulfide 2 and 3 were prepared. SmI2-mediated reductive metallation of these sulfides followed by reaction with ketones or aldehydes under Barbier conditions provided C2 hydroxyalkylated products 4 in yields ranged from 30% to 83%. High C2/C3 trans diastereoselectivity and mediocre diastereoselectivity at newly formed carbinolic center have been observed. The present method will open an avenue for the asymmetric synthesis of polyhydroxylated indolizidine alkaloids.

  20. DESFIBRAMENTO DE CAVACOS LAMINADOS DE BAMBUSA VULGARIS SCHRAD VISANDO À EXTRAÇÃO DE AMIDO

    Directory of Open Access Journals (Sweden)

    AZZINI ANISIO

    1998-01-01

    Full Text Available No presente estudo, cavacos laminados de Bambusa vulgaris Schrad com espessura reduzida (0,5 mm foram desfibrados visando à extração de amido e à separação das frações fibrosa e residual. O desfibramento dos cavacos foi realizado em liquidificador de copo invertido. Os resultados variaram de 52,16 a 69,36 g/kg para o amido, de 774,53 a 798,26 g/kg para a fração fibrosa e de 72,50 a 112,44 g/kg para a fração residual. O emprego de cavacos laminados com espessura variando de 0,403 a 0,489 mm favoreceu o desfibramento: viabilizou a extração de amido, dispensando o pré-amolecimento dos cavacos.

  1. Extremely bulky amido first row transition metal(II) halide complexes: potential precursors to low coordinate metal-metal bonded systems.

    Science.gov (United States)

    Hicks, Jamie; Jones, Cameron

    2013-04-01

    Reactions of the extremely bulky potassium amide complexes, [KL'(η(6)-toluene)] or [KL"] (L'/L" = N(Ar*)(SiR3), Ar* = C6H2{C(H)Ph2}2Me-2,6,4; R = Me (L') or Ph (L")), with a series of first row transition metal(II) halides have yielded 10 rare examples of monodentate amido first row transition metal(II) halide complexes, all of which were crystallographically characterized. They encompass the dimeric, square-planar chromium complexes, [{CrL'(THF)(μ-Cl)}2] and [{CrL"(μ-Cl)}2], the latter of which displays intramolecular η(2)-Ph···Cr interactions; the dimeric tetrahedral complexes, [{ML'(THF)(μ-Br)}2] (M = Mn or Fe), [{ML"(THF)(μ-X)}2] (M = Mn, Fe or Co; X = Cl or Br) and [{CoL"(μ-Cl)}2] (which displays intramolecular η(2)-Ph···Co interactions); and the monomeric zinc amides, [L'ZnBr(THF)] (three-coordinate) and [L"ZnBr] (two-coordinate). Solution state magnetic moment determinations on all but one of the paramagnetic compounds show them to be high-spin systems. Throughout, comparisons are made with related bulky terphenyl transition metal(II) halide complexes, and the potential for the use of the prepared complexes as precursors to low-valent transition metal systems is discussed.

  2. Multilayered Thin Films from Poly(amido amine)s and DNA

    NARCIS (Netherlands)

    Hujaya, S.D.; Engbersen, J.F.J.; Paulusse, J.M.J.

    2015-01-01

    Dip-coated multilayered thin films of poly(amido amine)s (PAAs) and DNA have been developed to provide surfaces with cell-transfecting capabilities. Three types of PAAs, differing in side chain functional groups, were synthesized and characterized for their properties in forming multilayered structu

  3. Surfactant-free Preparation of Highly Stable Zwitterionic Poly(amido amine) Nanogels with Minimal Cytotoxicity

    NARCIS (Netherlands)

    Ekkelenkamp, A.E.; Jansman, M.M.T.; Roelofs-Haarhuis, H.M.; Engbersen, J.F.J.; Paulusse, J.M.J.

    2016-01-01

    Narrowly dispersed zwitterionic poly(amido amine) (PAA) nanogels with a diameter of approximately 100 nm were prepared by a high-yielding and surfactant-free, inverse nanoprecipitation of PAA polymers. The resulting, negatively charged, nanogels (PAA-NG1) were functionalized with N,N-dimethylethylen

  4. How acidic are monomeric structural units of heparin?

    Science.gov (United States)

    Remko, Milan; Broer, Ria; Van Duijnen, Piet Th.

    2013-12-01

    Density functional theory methods with the B3LYP functional have been used to letter the acidity of carboxyl, O-sulfo and N-sulfo groups in six basic monomeric structural units of heparin (1-OMe ΔUA-2S, 1-OMe GlcN-S6S, 1,4-DiOMe GlcA, 1,4-DiOMe GlcN-S3S6S, 1,4-DiOMe IdoA-2S, and 1,4-DiOMe GlcN-S6S). The predicted gas-phase acidity of the acidic functional groups in the monomeric structural units of heparin is: O-sulfo > N-sulfo > carboxyl. The computed pKa values provide the same order of acidity as was observed in water solution. This implies that hydration does not change ordering of acidity of major acidic groups of monomeric structural units of heparin.

  5. Stable divalent germanium, tin and lead amino(ether)-phenolate monomeric complexes: structural features, inclusion heterobimetallic complexes, and ROP catalysis.

    Science.gov (United States)

    Wang, Lingfang; Roşca, Sorin-Claudiu; Poirier, Valentin; Sinbandhit, Sourisak; Dorcet, Vincent; Roisnel, Thierry; Carpentier, Jean-François; Sarazin, Yann

    2014-03-21

    Stable germanium(II) and lead(II) amido complexes {LO(i)}M(N(SiMe3)2) (M = Ge(II), Pb(II)) bearing amino(ether)phenolate ligands are readily available using the proteo-ligands {LO(i)}H of general formula 2-CH2NR2-4,6-tBu2-C6H2OH (i = 1, NR2 = N((CH2)2OCH3)2; i = 2, NR2 = NEt2; i = 3, NR2 = aza-15-crown-5) and M(N(SiMe3)2)2 precursors. The molecular structures of these germylenes and plumbylenes, as well as those of {LO(3)}GeCl, {LO(3)}SnCl and of the congeneric {LO(4)}Sn(II)(N(SiMe3)2) where NR2 = aza-12-crown-4, have been determined crystallographically. All complexes are monomeric, with 3-coordinate metal centres. The phenolate systematically acts as a N^O(phenolate) bidentate ligand, with no interactions between the metal and the O(side-arm) atoms in these cases (for {LO(1)}(-), {LO(3)}(-) and {LO(4)}(-)) where they could potentially arise. For each family, the lone pair of electrons essentially features ns(2) character, and there is little, if any, hybridization of the valence orbitals. Heterobimetallic complexes {LO(3)}M(N(SiMe3)2)·LiOTf, where the Li(+) cation sits inside the tethered crown-ether, were prepared by reaction of {LO(3)}M(N(SiMe3)2) and LiOTf (M = Ge(II), Sn(II)). The inclusion of Li(+) (featuring a close contact with the triflate anion) in the macrocycle bears no influence on the coordination sphere of the divalent tetrel element. In association with iPrOH, the amido germylenes, stannylenes and plumbylenes catalyse the controlled polymerisation of L- and racemic lactide. The activity increases linearly according to Ge(II) ≪ Sn(II) ≪ Pb(II). The simple germylenes generate very sluggish catalysts, but the activity is significantly boosted if the heterobimetallic complex {LO(3)}Ge(N(SiMe3)2)·LiOTf is used instead. On the other hand, with 10-25 equiv. of iPrOH, the plumbylenes afford highly active binary catalysts, converting 1000 or 5000 equiv. of monomer at 60 °C within 3 or 45 min, respectively, in a controlled fashion.

  6. Homotropic cooperativity of monomeric cytochrome P450 3A4

    Energy Technology Data Exchange (ETDEWEB)

    Baas, Bradley J.; Denisov, Ilia G.; Sligar, Stephen G. (UIUC)

    2010-11-16

    Mechanistic studies of mammalian cytochrome P450s are often obscured by the phase heterogeneity of solubilized preparations of membrane enzymes. The various protein-protein aggregation states of microsomes, detergent solubilized cytochrome or a family of aqueous multimeric complexes can effect measured substrate binding events as well as subsequent steps in the reaction cycle. In addition, these P450 monooxygenases are normally found in a membrane environment and the bilayer composition and dynamics can also effect these catalytic steps. Here, we describe the structural and functional characterization of a homogeneous monomeric population of cytochrome P450 3A4 (CYP 3A4) in a soluble nanoscale membrane bilayer, or Nanodisc [Nano Lett. 2 (2002) 853]. Cytochrome P450 3A4:Nanodisc assemblies were formed and purified to yield a 1:1 ratio of CYP 3A4 to Nanodisc. Solution small angle X-ray scattering was used to structurally characterize this monomeric CYP 3A4 in the membrane bilayer. The purified CYP 3A4:Nanodiscs showed a heretofore undescribed high level of homotropic cooperativity in the binding of testosterone. Soluble CYP 3A4:Nanodisc retains its known function and shows prototypic hydroxylation of testosterone when driven by hydrogen peroxide. This represents the first functional characterization of a true monomeric preparation of cytochrome P450 monooxygenase in a phospholipid bilayer and elucidates new properties of the monomeric form.

  7. Monomeric tartrate resistant acid phosphatase induces insulin sensitive obesity.

    Directory of Open Access Journals (Sweden)

    Pernilla Lång

    Full Text Available BACKGROUND: Obesity is associated with macrophage infiltration of adipose tissue, which may link adipose inflammation to insulin resistance. However, the impact of inflammatory cells in the pathophysiology of obesity remains unclear. Tartrate resistant acid phosphatase (TRAP is an enzyme expressed by subsets of macrophages and osteoclasts that exists either as an enzymatically inactive monomer or as an active, proteolytically processed dimer. PRINCIPAL FINDINGS: Using mice over expressing TRAP, we show that over-expression of monomeric, but not the dimeric form in adipose tissue leads to early onset spontaneous hyperplastic obesity i.e. many small fat cells. In vitro, recombinant monomeric, but not proteolytically processed TRAP induced proliferation and differentiation of mouse and human adipocyte precursor cells. In humans, monomeric TRAP was highly expressed in the adipose tissue of obese individuals. In both the mouse model and in the obese humans the source of TRAP in adipose tissue was macrophages. In addition, the obese TRAP over expressing mice exhibited signs of a low-grade inflammatory reaction in adipose tissue without evidence of abnormal adipocyte lipolysis, lipogenesis or insulin sensitivity. CONCLUSION: Monomeric TRAP, most likely secreted from adipose tissue macrophages, induces hyperplastic obesity with normal adipocyte lipid metabolism and insulin sensitivity.

  8. Produção e caracterização de maltodextrinas a partir de amidos de mandioca e batata-doce

    OpenAIRE

    Coutinho, Ana Paula Cerino [UNESP

    2007-01-01

    As maltodextrinas sao produtos da hidrolise parcial do amido e tem sido largamente usadas nas industrias de alimentos em muitos tipos de alimentos processados. Maltodextrinas sao classificadas de acordo com o grau de hidrolise do amido, que e expressa em dextrose equivalente (DE). Varias propriedades funcionais, como docura, solubilidade e viscosidade variam de acordo com a degradacao enzimatica e a fonte botanica do amido, e somente a caracterizacao pela dextrose equivalente (DE) se tornou i...

  9. Synthesis and structure of monomeric, trimeric, and mixed phenylcyanamides.

    Science.gov (United States)

    Brand, Harald; Mayer, Peter; Schulz, Axel; Soller, Thomas; Villinger, Alexander

    2008-06-02

    In a new synthetic approach phenylcyanamide (Hpca) was synthesized by methylation of phenylthiourea followed by a basic work-up. All products along the synthetic route have been fully characterized by means of NMR, IR, and X-ray studies. The first structural report of neutral mixed crystals of phenylcyanamide containing monomeric and trimeric Hpca is presented. Examination of these intriguing mixed crystals revealed the formation of distinct layers of monomeric and trimeric Hpca. These layers are interconnected by weak hydrogen bonds. The trimer represents triphenylisomelamine, which readily isomerizes to the triphenylmelamine in the melt, in accord with computations at the B3LYP level, indicating an exothermic process (DeltaH = -49.4 kcal mol(-1)). Pure trimeric Hpca (triphenylisomelamine) was obtained either by recrystallization of the mixed crystals from boiling water or by trimerization of monomeric Hpca in isopropanol for 12 h under reflux conditions. For comparison tritylcyanamide (Htca) and potassium phenylcyanamide as an [18]crown-6 complex [K([18]crown-6)pca] have been synthesized, and the solid-state structures were determined using X-ray diffraction techniques. The thermal behavior was studied by thermo-analytical experiments. In agreement with the experimental results, computations predict an exothermic cyclotrimerization process for Hpca (DeltaH = -41.3 kcal mol(-1)).

  10. Propriedades de pasta de amidos de arroz nativo e acetilados Pasting properties of native and acetylated rice starches

    Directory of Open Access Journals (Sweden)

    Josiane Bartz

    2012-05-01

    Full Text Available O amido de arroz apresenta características favoráveis a muitas aplicações industriais; no entanto, a natureza hidrofílica do amido na forma nativa pode apresentar algumas limitações para determinados tipos de processamento. Neste estudo, amido de arroz com médio teor de amilose foi acetilado sob catálise alcalina em duas condições reacionais para produzir acetatos de amido com diferentes graus de substituição (GS. A introdução de grupos acetila ao amido foi confirmada por espectroscopia de infravermelho com transformada de Fourier (FT-IV e os acetatos de amido produzidos foram avaliados quanto às suas propriedades de pasta em viscoamilógrafo (RVA. A acetilação ocasionou reduções em todas as propriedades de pasta avaliadas (temperatura de pasta, viscosidade mínima, pico de viscosidade, viscosidade final e tendência à retrogradação, sendo a redução mais intensa no amido acetilado com maior GS.Rice starch has characteristics suitable to many industrial applications, however, the hydrophilic nature of the starch in native form may present some limitations for some uses. In this study, rice starch with medium amylose content was acetylated under alkaline catalysis on two reaction conditions to produce starch acetates with different degrees of substitution (DS. The introduction of acetyl groups to the starch was confirmed by infrared Fourier transform (FT-IR and starch acetates produced were evaluated for their paste properties in viscoelastograf (RVA. Acetylation caused reductions in all properties paste (paste temperature, minimum viscosity, peak viscosity, final viscosity and retrogradation tendency being the most intense reduction in acetylated starch with greater GS.

  11. Enantioselective Michael reaction catalyzed by well-defined chiral ru amido complexes: isolation and characterization of the catalyst intermediate, ru malonato complex having a metal-carbon bond.

    Science.gov (United States)

    Watanabe, Masahito; Murata, Kunihiko; Ikariya, Takao

    2003-06-25

    Chiral Ru amido complexes promote asymmetric Michael addition of malonates to cyclic enones, leading to Michael adducts with excellent ee's, in which the chiral Ru amido complexes react with malonates to give isolable catalyst intermediates, chiral Ru malonato complexes bearing a metal bound C-nucleophile.

  12. Carbohydrate-interactive pDNA and siRNA gene vectors based on boronic acid functionalized poly(amido amine)s

    NARCIS (Netherlands)

    Piest, Martin; Ankone, Martinus J.K.; Engbersen, Johannes F.J.

    2013-01-01

    In order to evaluate the influence of incorporation of boronic acid groups on the properties of poly(amido amine)s as gene vectors, a novel poly(amido amine) copolymer p(CBA-ABOL/2AMPBA) containing ortho-aminomethylphenylboronic acid (2AMPBA) moieties was prepared by Michael-type polyaddition of a m

  13. Slow Unfolding of Monomeric Proteins from Hyperthermophiles with Reversible Unfolding

    Directory of Open Access Journals (Sweden)

    Atsushi Mukaiyama

    2009-03-01

    Full Text Available Based on the differences in their optimal growth temperatures microorganisms can be classified into psychrophiles, mesophiles, thermophiles, and hyperthermophiles. Proteins from hyperthermophiles generally exhibit greater stability than those from other organisms. In this review, we collect data about the stability and folding of monomeric proteins from hyperthermophilies with reversible unfolding, from the equilibrium and kinetic aspects. The results indicate that slow unfolding is a general strategy by which proteins from hyperthermophiles adapt to higher temperatures. Hydrophobic interaction is one of the factors in the molecular mechanism of the slow unfolding of proteins from hyperthermophiles.

  14. Addition-type polyimides from solutions of monomeric reactants

    Science.gov (United States)

    Delvigs, P.; Serafini, T. T.; Lightsey, G. R.

    1972-01-01

    The monomeric reactants approach was used to fabricate addition-type polyimide/graphite fiber composites with improved mechanical properties and thermal stability characteristics over those of composites derived from addition-type amide acid prepolymers. A screening study of 24 different monomer combinations was performed. The results of a more extensive investigation of a selected number of monomer combinations showed that the combination providing the best thermomechanical properties was 5-norbornene-2,3-dicarboxylic acid monomethyl ester/4,4'-methylenedianiline/3,3'4,4'-benzophenone tetracarboxylic acid dimethyl ester at a molar ratio of 2/3.09/2.09.

  15. Desenvolvimento de nanocompósitos à base de amido de batata

    Directory of Open Access Journals (Sweden)

    Luciana Macedo Brito

    2013-01-01

    Full Text Available Nanocompósitos de amido de batata foram preparados pelo método de intercalação por solução, com a adição de argilas montmorilonita: organicamente modificada (Viscogel B8 e não modificada argila sódica (NT25 e de sílicas: modificada (R972 e não modificada (A200. Os nanocompósitos foram caracterizados pelas técnicas convencionais de difratometria de raios X e análise termogravimétrica. Foram caracterizados também por uma técnica denominada como não convencional, a ressonância magnética nuclear (RMN de baixo campo, que é alternativa e efetiva na caracterização de nanocompósitos. Com ela, pode-se investigar a dispersão das nanocargas pelo grau de intercalação e/ou esfoliação, além de verificar a distribuição e modificações da mobilidade molecular da matriz polimérica. Os materiais nanoestruturados obtidos com as argilas apresentaram boa dispersão e formação de nanomateriais mistos, com diferentes graus de intercalação e esfoliação. Ao adicionar as sílicas na matriz de amido pode-se observar uma diminuição da mobilidade do material, este efeito foi observado para ambas às sílicas utilizadas. Utilizando a técnica de TGA verificou-se um ligeiro aumento na estabilidade térmica do material produzido em relação ao amido.

  16. LRP1 Modulates APP Intraneuronal Transport and Processing in Its Monomeric and Dimeric State

    Directory of Open Access Journals (Sweden)

    Claus U. Pietrzik

    2017-04-01

    Full Text Available The low-density lipoprotein receptor-related protein 1, LRP1, interacts with APP and affects its processing. This is assumed to be mostly caused by the impact of LRP1 on APP endocytosis. More recently, also an interaction of APP and LRP1 early in the secretory pathway was reported whereat retention of LRP1 in the ER leads to decreased APP cell surface levels and in turn, to reduced Aβ secretion. Here, we extended the biochemical and immunocytochemical analyses by showing via live cell imaging analyses in primary neurons that LRP1 and APP are transported only partly in common (one third but to a higher degree in distinct fast axonal transport vesicles. Interestingly, co-expression of LRP1 and APP caused a change of APP transport velocities, indicating that LRP1 recruits APP to a specific type of fast axonal transport vesicles. In contrast lowered levels of LRP1 facilitated APP transport. We further show that monomeric and dimeric APP exhibit similar transport characteristics and that both are affected by LRP1 in a similar way, by slowing down APP anterograde transport and increasing its endocytosis rate. In line with this, a knockout of LRP1 in CHO cells and in primary neurons caused an increase of monomeric and dimeric APP surface localization and in turn accelerated shedding by meprin β and ADAM10. Notably, a choroid plexus specific LRP1 knockout caused a much higher secretion of sAPP dimers into the cerebrospinal fluid compared to sAPP monomers. Together, our data show that LRP1 functions as a sorting receptor for APP, regulating its cell surface localization and thereby its processing by ADAM10 and meprin β, with the latter exhibiting a preference for APP in its dimeric state.

  17. LRP1 Modulates APP Intraneuronal Transport and Processing in Its Monomeric and Dimeric State.

    Science.gov (United States)

    Herr, Uta-Mareike; Strecker, Paul; Storck, Steffen E; Thomas, Carolin; Rabiej, Verena; Junker, Anne; Schilling, Sandra; Schmidt, Nadine; Dowds, C Marie; Eggert, Simone; Pietrzik, Claus U; Kins, Stefan

    2017-01-01

    The low-density lipoprotein receptor-related protein 1, LRP1, interacts with APP and affects its processing. This is assumed to be mostly caused by the impact of LRP1 on APP endocytosis. More recently, also an interaction of APP and LRP1 early in the secretory pathway was reported whereat retention of LRP1 in the ER leads to decreased APP cell surface levels and in turn, to reduced Aβ secretion. Here, we extended the biochemical and immunocytochemical analyses by showing via live cell imaging analyses in primary neurons that LRP1 and APP are transported only partly in common (one third) but to a higher degree in distinct fast axonal transport vesicles. Interestingly, co-expression of LRP1 and APP caused a change of APP transport velocities, indicating that LRP1 recruits APP to a specific type of fast axonal transport vesicles. In contrast lowered levels of LRP1 facilitated APP transport. We further show that monomeric and dimeric APP exhibit similar transport characteristics and that both are affected by LRP1 in a similar way, by slowing down APP anterograde transport and increasing its endocytosis rate. In line with this, a knockout of LRP1 in CHO cells and in primary neurons caused an increase of monomeric and dimeric APP surface localization and in turn accelerated shedding by meprin β and ADAM10. Notably, a choroid plexus specific LRP1 knockout caused a much higher secretion of sAPP dimers into the cerebrospinal fluid compared to sAPP monomers. Together, our data show that LRP1 functions as a sorting receptor for APP, regulating its cell surface localization and thereby its processing by ADAM10 and meprin β, with the latter exhibiting a preference for APP in its dimeric state.

  18. Amino Azaxylylenes Photogenerated from o-Amido Imines: Photoassisted Access to Complex Spiro-Poly-Heterocycles.

    Science.gov (United States)

    Mukhina, Olga A; Kuznetsov, Dmitry M; Cowger, Teresa M; Kutateladze, Andrei G

    2015-09-21

    Upon irradiation, cyclic imines containing o-amido groups are shown to produce reactive intermediates, amino azaxylylenes, which undergo intramolecular cycloadditions to tethered unsaturated pendants to yield complex N,O-heterocycles having an additional spiro-connected nitrogen heterocyclic moiety. Modular assembly of the photoprecursors allows expeditious increase of the complexity of the target poly-heterocyclic scaffolds with a minimal number of experimentally simple reaction steps. The photocyclization and subsequent postphotochemical transformations are accompanied by an increase of Lovering's fsp3 factor, thus producing unprecedented three-dimensional molecular architectures, and offering extended sampling of chemical space.

  19. Fontes de amido no concentrado de bovinos superprecoces de diferentes classes sexuais

    Directory of Open Access Journals (Sweden)

    L.C.V. Ítavo

    2014-08-01

    Full Text Available Objetivou-se avaliar duas fontes de amido (milho ou sorgo no concentrado e três classes sexuais sobre o consumo de nutrientes, o desempenho e as características da carcaça de bovinos superprecoces. Foram utilizados 30 animais cruzados Beefalo-Nelore, com peso corporal médio inicial de 234,38±26,17kg, em delineamento inteiramente ao acaso, em esquema fatorial 2x3 (duas fontes de amido e três classes sexuais: fêmeas, machos castrados e machos não castrados. O período experimental foi de 224 dias. Na fase inicial (zero-17 semanas, os ganhos de peso total (GPT e diário (GMD foram 150,62 e 108,62kg e 1,27 e 0,91kg/dia, respectivamente, para milho e sorgo. Na fase final (17-32 semanas, houve efeito da fonte de amido para o peso de carcaça, com médias de 273,00 e 231,95kg, respectivamente, para os tratamentos com milho e sorgo. Houve efeito de classe sexual para GP, GMD e eficiência alimentar, com médias de GP iguais a 98,17, 124,70 e 119,70kg, GMD de 0,93, 1,19 e 1,14kg/dia e 8,66, 12,24 e 11,09%, respectivamente, para fêmeas, machos castrados e machos não castrados. Espessura de gordura subcutânea (EGS apresentou médias de 10,50; 5,97 e 5,51mm, respectivamente, para fêmeas, machos castrados e machos não castrados. Recomenda-se o milho como fonte de amido na fase inicial do confinamento de superprecoces. Na fase final (17-32 semanas, não há distinção entre milho ou sorgo. As fêmeas apresentaram maior EGS, e os machos, castrados e não castrados, apresentaram maior eficiência alimentar na fase final do confinamento.

  20. Characterization of monomeric intermediates during VSV glycoprotein structural transition.

    Directory of Open Access Journals (Sweden)

    Aurélie A Albertini

    2012-02-01

    Full Text Available Entry of enveloped viruses requires fusion of viral and cellular membranes, driven by conformational changes of viral glycoproteins. Crystal structures provide static pictures of pre- and post-fusion conformations of these proteins but the transition pathway remains elusive. Here, using several biophysical techniques, including analytical ultracentrifugation, circular dichroïsm, electron microscopy and small angle X-ray scattering, we have characterized the low-pH-induced fusogenic structural transition of a soluble form of vesicular stomatitis virus (VSV glycoprotein G ectodomain (G(th, aa residues 1-422, the fragment that was previously crystallized. While the post-fusion trimer is the major species detected at low pH, the pre-fusion trimer is not detected in solution. Rather, at high pH, G(th is a flexible monomer that explores a large conformational space. The monomeric population exhibits a marked pH-dependence and adopts more elongated conformations when pH decreases. Furthermore, large relative movements of domains are detected in absence of significant secondary structure modification. Solution studies are complemented by electron micrographs of negatively stained viral particles in which monomeric ectodomains of G are observed at the viral surface at both pH 7.5 and pH 6.7. We propose that the monomers are intermediates during the conformational change and thus that VSV G trimers dissociate at the viral surface during the structural transition.

  1. π Type Lithium Bond Interaction between Ethylene,Acetylene,or Benzene and Amido-lithium

    Institute of Scientific and Technical Information of China (English)

    YUAN,Kun; LIU,Yanzhi; L(U),Lingling; ZHU,Yuancheng; ZHANG,Ji; ZHANG,dunyan

    2009-01-01

    The optimization geometries and interaction energy corrected by basis set super-position error (BSSE) of the lithium bond complexes between ethylene,acetylene,or benzene and amido-lithium have been calculated at the B3L YP/6-311++G** and MP2/6-311 ++-G** levels.And only one configuration was obtained for each lithium bond system.All the equilibrium geometries were confirmed to be stable state by analytical frequency computations.The calculations showed that all the N(2)-Li(4) bond lengths increased obviously and the red shift of N(2)-Li(4) stretching frequency occurred after complexes formed.The calculated binding energies with BSSE and zero-point vibrational energy corrections of complexes Ⅰ,Ⅱ and Ⅲ are -26.04,-24.86 and -30.02 kJ·mol-1 via an MP2 method,respectively.Natural bond orbital (NBO) theory analysis revealed that the three complexes were all formed with π type lithium bond interaction between ethylene,acetylene,or benzene and amido-lithium.

  2. Aliphatic Hyperbranched Poly(amido amine)s(PAMAMs): Preparation and Modification

    Institute of Scientific and Technical Information of China (English)

    LIU Cui-hua; GAO Chao; YAN De-yue

    2005-01-01

    A series of water soluble aliphatic hyperbranched poly(amido amine)s(PAMAMs) with the same or similar chemical structure of poly(amido amine) dendrimer was successfully synthesized from commercially available AB and Cn types of monomers by one-pot polymerization via the couple-monomer methodology(CMM). The AB type monomer used in this paper was methyl acrylate, and Cn monomers were multi-amino compounds such as ethylenediamine(EDA), diethylenetriamine(DETA), triethylenetetraamine(TETA), tetraethylenepentaamine(TEPA) and pentaethylenehexamine(PEHA). The reaction mechanism was investigated by means of the mass spectra of the reaction intermediates. Adjusting the feed ratio of AB to Cn, hyperbranched polymers with different terminal groups and properties were obtained. FTIR, NMR, DSC, and TGA were used to characterize the polymers. It was found that the polymers' properties such as solubility, thermal behaviour and encapsulation capability varied with changing the feed ratio of AB to Cn. Benzoyl and palmitoyl groups were introduced into these macromolecules by acidylation to form amphiphilic hyperbranched polymers which have a high capability to encapsulate water soluble dyes such as Congo red. It is expected that the hyperbranched PAMAMs can play an important role in the industrial applications, such as coatings, cross-linking and phase-transferring agents because of their versatility and availability.

  3. Poly(amido amine)s as Gene Delivery Vectors: Effects of Quaternary Nicotinamide Moieties in the Side Chains

    NARCIS (Netherlands)

    Mateos Timoneda, Miguel A.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan; Engbersen, Johan F.J.

    2008-01-01

    To evaluate the effect of quaternary nicotinamide pendant groups on gene delivery properties, a series of poly(amido amine) (co)polymers were synthesized by Michael addition polymerization of N, N-cystaminebisacrylamide with variable ratios of 1-(4-aminobutyl)-3-carbamoylpyridinium (Nic-BuNH2), and

  4. 3-Amido-3-aryl-piperidines: A Novel Class of Potent, Selective, and Orally Active GlyT1 Inhibitors.

    Science.gov (United States)

    Pinard, Emmanuel; Alberati, Daniela; Alvarez-Sanchez, Ruben; Brom, Virginie; Burner, Serge; Fischer, Holger; Hauser, Nicole; Kolczewski, Sabine; Lengyel, Judith; Mory, Roland; Saladin, Christian; Schulz-Gasch, Tanja; Stalder, Henri

    2014-04-10

    3-Amido-3-aryl-piperidines were discovered as a novel structural class of GlyT1 inhibitors. The structure-activity relationship, which was developed, led to the identification of highly potent compounds exhibiting excellent selectivity against the GlyT2 isoform, drug-like properties, and in vivo activity after oral administration.

  5. Efeito do ultrassom na extração e modificação de amidos

    Directory of Open Access Journals (Sweden)

    Cristiany Oliveira Bernardo

    2016-04-01

    Full Text Available RESUMO: O ultrassom é considerado uma tecnologia limpa, por possibilitar menor gasto de energia, de substâncias químicas e menor geração de efluentes. Além disso, proporciona menor tempo de processamento e reduz a necessidade de aplicação de calor em vários processos. Por isso, tem sido alvo de pesquisa e desenvolvimento na indústria de alimentos, tanto para substituir, quanto para aperfeiçoar ou acelerar técnicas convencionais de processamento. Dentre as diferentes possibilidades de utilização na indústria de alimentos, o ultrassom pode ser considerado uma alternativa para substituir ou reduzir a utilização de substâncias químicas em processos de extração ou modificação de amidos. Quando utilizado na extração, possibilita maior pureza do amido obtido. Já na modificação, algumas alterações nos grânulos de amido podem ser provocadas pelo ultrassom, mas dependem da origem botânica, da composição do amido, dos parâmetros do equipamento e das condições de processamento.

  6. Isolation and Characterization of Lewis Base Stabilized Monomeric Parent Stibanylboranes.

    Science.gov (United States)

    Marquardt, Christian; Hegen, Oliver; Hautmann, Matthias; Balázs, Gábor; Bodensteiner, Michael; Virovets, Alexander V; Timoshkin, Alexey Y; Scheer, Manfred

    2015-10-26

    The synthesis of the Lewis base stabilized monomeric parent compound of stibanylboranes, "H2 Sb-BH2 ", is reported. Through a salt metathesis route, the silyl-substituted compounds (Me3 Si)2 Sb-BH2 ⋅LB (LB=NMe3 , NHC(Me) ) were synthesized as representatives of derivatives with a Sb-B σ bond. Under very mild conditions, they could be transformed into the target compounds Me3 N⋅H2 B-HSb-BH2 ⋅NMe3 and H2 Sb-BH2 ⋅NHC(Me) , respectively. The products were characterized by X-ray structure analysis, NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations give further insight into the stability and bonding of these unique compounds.

  7. Light-induced structural changes in a monomeric bacteriophytochrome

    Directory of Open Access Journals (Sweden)

    Heikki Takala

    2016-09-01

    Full Text Available Phytochromes sense red light in plants and various microorganism. Light absorption causes structural changes within the protein, which alter its biochemical activity. Bacterial phytochromes are dimeric proteins, but the functional relevance of this arrangement remains unclear. Here, we use time-resolved X-ray scattering to reveal the solution structural change of a monomeric variant of the photosensory core module of the phytochrome from Deinococcus radiodurans. The data reveal two motions, a bend and a twist of the PHY domain with respect to the chromophore-binding domains. Infrared spectroscopy shows the refolding of the PHY tongue. We conclude that a monomer of the phytochrome photosensory core is sufficient to perform the light-induced structural changes. This implies that allosteric cooperation with the other monomer is not needed for structural activation. The dimeric arrangement may instead be intrinsic to the biochemical output domains of bacterial phytochromes.

  8. Characterization of the Partially Folded Monomeric Intermediate of Creatine Kinase

    Institute of Scientific and Technical Information of China (English)

    朴龙斗; 周海梦

    2002-01-01

    The importance of understanding the protein folding pathway and intermediates is well recognized on the basis of extensive studies of protein folding in vitro and in vivo. Creatine kinase (CK) is a typical model for studying unfolding and refolding of proteins due to several interesting properties. Recent studies on the folding of CK show that its partially folded monomeric intermediate is present kinetically and is stable at equilibrium. The present paper contains 33 References as a mini review to characterize the properties of CK from studies on the CK folding pathway. Characterization of these intermediates is an essential step toward understanding the mechanism of protein folding. Some well-determined schemes are suggested as protein folding models.

  9. Single Molecule Spectroscopy of Monomeric LHCII: Experiment and Theory

    CERN Document Server

    Malý, Pavel; van Grondelle, Rienk; Mančal, Tomáš

    2015-01-01

    We derive approximate equations of motion for excited state dynamics of a multilevel open quantum system weakly interacting with light to describe fluorescence detected single molecule spectra. Based on the Frenkel exciton theory, we construct a model for the chlorophyll part of the LHCII complex of higher plants and its interaction with previously proposed excitation quencher in the form of the lutein molecule Lut 1. The resulting description is valid over a broad range of timescales relevant for single molecule spectroscopy, i.e. from ps to minutes. Validity of these equations is demonstrated by comparing simulations of ensemble and single-molecule spectra of monomeric LHCII with experiments. Using a conformational change of the LHCII protein as a switching mechanism, the intensity and spectral time traces of individual LHCII complexes are simulated, and the experimental statistical distributions are reproduced. Based on our model, it is shown that with reasonable assumptions about its interaction with chlo...

  10. mKikGR, a monomeric photoswitchable fluorescent protein.

    Directory of Open Access Journals (Sweden)

    Satoshi Habuchi

    Full Text Available The recent demonstration and utilization of fluorescent proteins whose fluorescence can be switched on and off has greatly expanded the toolkit of molecular and cell biology. These photoswitchable proteins have facilitated the characterization of specifically tagged molecular species in the cell and have enabled fluorescence imaging of intracellular structures with a resolution far below the classical diffraction limit of light. Applications are limited, however, by the fast photobleaching, slow photoswitching, and oligomerization typical for photoswitchable proteins currently available. Here, we report the molecular cloning and spectroscopic characterization of mKikGR, a monomeric version of the previously reported KikGR that displays high photostability and switching rates. Furthermore, we present single-molecule imaging experiments that demonstrate that individual mKikGR proteins can be localized with a precision of better than 10 nanometers, suggesting their suitability for super-resolution imaging.

  11. Efeitos de tratamentos hidrotérmicos nas propriedades viscográficas e amidos resistentes em féculas de mandioca

    OpenAIRE

    2008-01-01

    Amidos naturais muitas vezes não têm características específicas para um processamento industrial, assim, amidos modificados são usados para proporcionar aos produtos amiláceos propriedades desejáveis tais como textura, aparência, maciez e outras. As modificações produzidas nos amidos geralmente repercutem em algumas de suas propriedades físicas tais como: temperatura de pasta, viscosidade, quebra de viscosidade, tendência de retrogradação. Os tratamentos hidrotérmicos modificam as propriedad...

  12. Estudo do amido de farinhas comerciais comestíveis Characterization of commercial edible starch flours

    Directory of Open Access Journals (Sweden)

    Bianca N. B. Lima

    2012-01-01

    Full Text Available O amido em quatro tipos de farinhas comerciais para uso doméstico em preparações culinárias foi caracterizado pelas técnicas de espectroscopia de absorção na região do infravermelho com Transformada de Fourier (FTIR, difração de raios X (DRX, análise termogravimétrica e ressonância magnética nuclear de baixo campo, por meio da determinação do tempo de relaxação spin-rede do núcleo de hidrogênio (T1H.Four commercial flour samples with starch components were studied. They were characterized by Infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and low field NMR (T1H.

  13. Amido fosfatado : obtenção, propriedades e efeito de ingredientes na sua viscosidade

    OpenAIRE

    1982-01-01

    Resumo: Fosfato-monoésteres de amido de milho com D.S. de 0,01 a 0,15 foram preparados variando-se as temperaturas e tempos de pirólise e as concentrações de fosfato na mistura de reação. Os produtos obtidos foram analisados quanto a viscosidade, grau de substituição (D.S.), cor, solubilidade e absorção de água. Os efeitos do cloreto de sódio, da sacarose e do pH na viscosidade dos FMA também foram investigados. Foi observado que o incremento da concentração de tampão fosfato de 2,0 M para 4,...

  14. Triclosan-loaded poly(amido amine) dendrimer for simultaneous treatment and remineralization of human dentine.

    Science.gov (United States)

    Zhou, Yan; Yang, Jiaojiao; Lin, Zaifu; Li, Jiyao; Liang, Kunneng; Yuan, He; Li, Sheyu; Li, Jianshu

    2014-03-01

    In order to treat dental caries of damaged dentine, triclosan-loaded carboxyl-terminated poly(amido amine) dendrimer (PAMAM-COOH) is prepared and characterized. While being incubated in artificial saliva, triclosan-loaded PAMAM-COOH formulation can induce in situ remineralization of hydroxyapatite (HA) on etched dentine, and the regenerated HA has a similar crystal structure with natural dentine. It can also release the encapsulated triclosan for a long period. The interesting drug release profiles are controlled by both dendrimer encapsulation capability and the mineralization degree, which are ideal to obtain multifunctional properties of long-term release of anti-bacterial drug for local treatment during the remineralization process. The triclosan-loaded G4-COOH provides a general strategy to cure dental caries and repair damaged dentine at the same time, which forms a potential restorative material for dental repair.

  15. Blendas de amido termoplástico e polietileno grafitizado (enxertado)

    OpenAIRE

    Oládio Dias Miguel

    2014-01-01

    O amido termoplástico (TPS) é um material biodegradável que tem sido bastante estudado em função do seu baixo custo e pelo fato de ser derivado de fontes renováveis. Contudo, o TPS apresenta limitações mesmo para aplicação em produtos de baixos requisitos devido a conjunto de fatores como sua baixa propriedade mecânica, térmica, e de resistência à umidade, além de possuir baixa compatibilidade com outros polímeros sintéticos. Nesse trabalho foi testada a modificações do TPS com ácido cítrico ...

  16. Properties of monomeric paramyosin using a transient electric birefringence techniques.

    Science.gov (United States)

    DeLaney, D; Krause, S

    1976-01-01

    Paramyosin samples obtained from the chowder clam, Mercenaria mercenaria, by different extraction techniques were studied using transient electric birefringence techniques. The protein remain monomeric (unaggregated) in 1 mM buffer solution at pH 3.1 to 3.8 and near pH 10. At pH 3.2, the molecules obtained by different extraction techniques exhibit rotational diffusion constants that indicate a 5% difference in length between them, with the probable native form of paramyosin being the longer species. This difference in rotational diffusion constant disappears at higher pH, and, in addition, a large difference in dipole moment between the molecules observed at pH 3.2 also disappears at high pH. These results are used to hypothesize that the rodlike native paramyosin molecules have one or two partly flexible portions on their ends; at one end of each molecule this portion probably contains excess basic amino acids which are charged at low pH to account for the higher dipole moment of this form of paramyosin at these low pH values. At pH 3.2, these portions of the macromolecule are not flexible and act as stiff parts of the rodlike molecules, but they gradually become flexible at higher pH. Possible mechanisms for this change in flexibility are discussed.

  17. Labeling Monomeric Insulin with Renal-Clearable Luminescent Gold Nanoparticles.

    Science.gov (United States)

    Vinluan, Rodrigo D; Yu, Mengxiao; Gannaway, Melissa; Sullins, Justin; Xu, Jing; Zheng, Jie

    2015-12-16

    In the native physiological environment, inorganic nanoparticles (NPs) often induce nonspecific protein adsorption, which could significantly alter the function of the proteins they labeled. As a result, small fluorescent dyes are still widely used in the imaging of proteins in animals due to their minimal interference with protein function. Here, we used monomeric insulin as a model and compared its bioactivity before and after labeling with renal-clearable near-infrared-emitting gold NPs. These NPs were chosen because they have high resistance to serum protein adsorption and low nonspecific accumulation. We have found that a 1:1 insulin-NP ratio can be achieved, where the insulin-NPs show minimal serum protein binding with fully retained bioactivity comparable to that of unlabeled insulin. These results show a proof of concept that renal-clearable NPs can behave like small molecules in protein labeling without changing the individual protein's function, laying down a foundation for in vivo tracking of proteins with multimodality imaging techniques.

  18. Substrate-Induced Dimerization of Engineered Monomeric Variants of Triosephosphate Isomerase from Trichomonas vaginalis.

    Directory of Open Access Journals (Sweden)

    Samuel Lara-Gonzalez

    Full Text Available The dimeric nature of triosephosphate isomerases (TIMs is maintained by an extensive surface area interface of more than 1600 Å2. TIMs from Trichomonas vaginalis (TvTIM are held in their dimeric state by two mechanisms: a ball and socket interaction of residue 45 of one subunit that fits into the hydrophobic pocket of the complementary subunit and by swapping of loop 3 between subunits. TvTIMs differ from other TIMs in their unfolding energetics. In TvTIMs the energy necessary to unfold a monomer is greater than the energy necessary to dissociate the dimer. Herein we found that the character of residue I45 controls the dimer-monomer equilibrium in TvTIMs. Unfolding experiments employing monomeric and dimeric mutants led us to conclude that dimeric TvTIMs unfold following a four state model denaturation process whereas monomeric TvTIMs follow a three state model. In contrast to other monomeric TIMs, monomeric variants of TvTIM1 are stable and unexpectedly one of them (I45A is only 29-fold less active than wild-type TvTIM1. The high enzymatic activity of monomeric TvTIMs contrast with the marginal catalytic activity of diverse monomeric TIMs variants. The stability of the monomeric variants of TvTIM1 and the use of cross-linking and analytical ultracentrifugation experiments permit us to understand the differences between the catalytic activities of TvTIMs and other marginally active monomeric TIMs. As TvTIMs do not unfold upon dimer dissociation, herein we found that the high enzymatic activity of monomeric TvTIM variants is explained by the formation of catalytic dimeric competent species assisted by substrate binding.

  19. Extração e caracterização de amido de Adlay (coix lacryma Jobi L.)

    OpenAIRE

    1987-01-01

    Resumo: O presente trabalho objetivou o estudo das condições de extração de amido do cereal Adlay (Coix lacryma jobi L.), assim como a caracterização físico química desta provável fonte de amido. A composição química do grão de Adlay apresentou, assim como outros cereais, um alto teor de carboidratos (69,51%), porém também ura teor relativamente alto de proteínas (16,82%). Os estudos de beneficiamento e moagem da semente mostraram que é possível produzir farinhas utilizando a beneficiadora d...

  20. Stereoretentive Addition of N-tert-Butylsulfonyl-α-Amido Silanes to Aldehydes, Ketones, α,β-Unsaturated Esters, and Imines.

    Science.gov (United States)

    Mita, Tsuyoshi; Saito, Keisuke; Sugawara, Masumi; Sato, Yoshihiro

    2016-05-20

    Enantioenriched N-tert-butylsulfonyl-α-amido silanes were successfully reacted with aldehydes, ketones, imines, and α,β-unsaturated esters in the presence of a sub-stoichiometric amount of CsF (0.5 equiv) in 1,2-dimethoxyethane (DME) at -20 °C to afford the corresponding coupling products with up to 89 % enantiospecificity in a retentive manner.

  1. ISOTERMAS E CALOR ISOSTÉRICO DE ADSORÇÃO DA ÁGUA DO AMIDO DE QUINOA

    Directory of Open Access Journals (Sweden)

    AUGUSTO PUMACAHUA RAMOS

    2017-07-01

    Full Text Available A quinoa possui mais de 60% de amido, sendo uma alternativa de extração e comercialização. Para isto é necessário conhecer o comportamento do amido frente à temperatura e umidade relativa do ar. O objetivo desta pesquisa foi avaliar as isotermas de adsorção do amido de quinoa em cinco temperaturas (20, 30, 40, 50 e 60ºC e dez atividades de água (0,036 a 0,907. Os pontos experimentais foram ajustados aos modelos matemáticos GAB, Oswin, Henderson, Peleg e Ferro-Foltan. Foram determinadas as energias de ativação da adsorção da água pelas constantes do modelo GAB e o calor isostérico pelo modelo de Peleg. As isotermas mostraram ser do tipo II na classificação de Brunauer. Os teores de água da monocamada (Xm determinados pelo modelo de GAB variaram de 7,90% a 10,38% base seca (b.s. para temperaturas de 60 e 20°C e as energias de ativação obtidas pelas constantes Xm, C e K do modelo de GAB foram de 300; 160 e 6 kJ/kg, respectivamente. O calor isostérico de adsorção foi de 3732 kJ/kg para umidade de equilíbrio de 0,5% b.s. e diminuiu com o aumento da umidade até valor próximo ao calor latente de vaporização da água pura a 36% b.s. As propriedades determinadas são características de amidos com elevado teor de amilopectina.

  2. A bis(amido) ligand set that supports two-coordinate chromium in the +1, +2, and +3 oxidation states†

    Science.gov (United States)

    Cai, Irene C.; Lipschutz, Michael I.

    2014-01-01

    The amido ligand –N(SiiPr3)DIPP (DIPP = 2,6-diisopropylphenyl) has been used to prepare two-coordinate complexes of CrI, CrII, and CrIII. The two-coordinate CrII complex has also been used to prepare a three-coordinate CrIII iodide complex, which can be used to access a stable CrIII methyl species. PMID:25222516

  3. A bis(amido) ligand set that supports two-coordinate chromium in the +1, +2, and +3 oxidation states.

    Science.gov (United States)

    Cai, Irene C; Lipschutz, Michael I; Tilley, T Don

    2014-11-01

    The amido ligand -N(Si(i)Pr3)DIPP (DIPP = 2,6-diisopropylphenyl) has been used to prepare two-coordinate complexes of Cr(I), Cr(II), and Cr(III). The two-coordinate Cr(II) complex has also been used to prepare a three-coordinate Cr(III) iodide complex, which can be used to access a stable Cr(III) methyl species.

  4. Synthesis and reactivity of a conveniently prepared two-coordinate bis(amido) nickel(II) complex.

    Science.gov (United States)

    Lipschutz, Michael I; Tilley, T Don

    2012-07-21

    A strictly two-coordinate nickel(II) bis(amido) complex has been prepared and its reactivity towards a variety of small molecules is described. Ni[N(SiMe(3))(DIPP)](2) reacts with DMAP and acetonitrile to form T-shaped three-coordinate complexes, and preliminary results show that Ni[N(SiMe(3))(DIPP)](2) is a catalyst for the hydrosilation of olefins with secondary silanes at ambient temperature.

  5. Contribution of Monomeric Anthocyanins to the Color of Young Red Wine: Statistical and Experimental Approaches.

    Science.gov (United States)

    Han, Fu Liang; Li, Zheng; Xu, Yan

    2015-12-01

    Monomeric anthocyanin contributions to young red wine color were investigated using partial least square regression (PLSR) and aqueous alcohol solutions in this study. Results showed that the correlation between the anthocyanin concentration and the solution color fitted in a quadratic regression rather than linear or cubic regression. Malvidin-3-O-glucoside was estimated to show the highest contribution to young red wine color according to its concentration in wine, whereas peonidin-3-O-glucoside in its concentration contributed the least. The PLSR suggested that delphinidin-3-O-glucoside and peonidin-3-O-glucoside under the same concentration resulted in a stronger color of young red wine compared with malvidin-3-O-glucoside. These estimates were further confirmed by their color in aqueous alcohol solutions. These results suggested that delphinidin-3-O-glucoside and peonidin-3-O-glucoside were primary anthocyanins to enhance young red wine color by increasing their concentrations. This study could provide an alternative approach to improve young red wine color by adjusting anthocyanin composition and concentration.

  6. Crystal structure of monomeric photosystem II from Thermosynechococcus elongatus at 3.6-a resolution.

    Science.gov (United States)

    Broser, Matthias; Gabdulkhakov, Azat; Kern, Jan; Guskov, Albert; Müh, Frank; Saenger, Wolfram; Zouni, Athina

    2010-08-20

    The membrane-embedded photosystem II core complex (PSIIcc) uses light energy to oxidize water in photosynthesis. Information about the spatial structure of PSIIcc obtained from x-ray crystallography was so far derived from homodimeric PSIIcc of thermophilic cyanobacteria. Here, we report the first crystallization and structural analysis of the monomeric form of PSIIcc with high oxygen evolution capacity, isolated from Thermosynechococcus elongatus. The crystals belong to the space group C222(1), contain one monomer per asymmetric unit, and diffract to a resolution of 3.6 A. The x-ray diffraction pattern of the PSIIcc-monomer crystals exhibit less anisotropy (dependence of resolution on crystal orientation) compared with crystals of dimeric PSIIcc, and the packing of the molecules within the unit cell is different. In the monomer, 19 protein subunits, 35 chlorophylls, two pheophytins, the non-heme iron, the primary plastoquinone Q(A), two heme groups, 11 beta-carotenes, 22 lipids, seven detergent molecules, and the Mn(4)Ca cluster of the water oxidizing complex could be assigned analogous to the dimer. Based on the new structural information, the roles of lipids and protein subunits in dimer formation of PSIIcc are discussed. Due to the lack of non-crystallographic symmetry and the orientation of the membrane normal of PSIIcc perpendicular ( approximately 87 degrees ) to the crystallographic b-axis, further information about the structure of the Mn(4)Ca cluster is expected to become available from orientation-dependent spectroscopy on this new crystal form.

  7. SGCC successfully developed large-capacity sodium-sulfur monomeric battery

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Through many years' cooperation,SGCC and Shanghai Silicate Research Institute of Chinese Academy of Science successfully developed 650 ampere-hours capacity sodium-sulfur monomeric storage battery with the independent intellectual property right

  8. Amphiphile dependency of the monomeric and dimeric forms of acetylcholinesterase from human erythrocyte membrane.

    Science.gov (United States)

    Ott, P; Brodbeck, U

    1984-08-08

    Human erythrocyte membrane-bound acetylcholinesterase was converted to a monomeric species by treatment of ghosts with 2-mercaptoethanol and iodoacetic acid. After solubilization with Triton X-100, the reduced and alkylated enzyme was partially purified by affinity chromatography and separated from residual dimeric enzyme by sucrose density gradient centrifugation in a zonal rotor. Monomeric and dimeric acetylcholinesterase showed full enzymatic activity in presence of Triton X-100 whereas in the absence of detergent, activity was decreased to approx. 20% and 15%, respectively. Preformed egg phosphatidylcholine vesicles fully sustained activity of the monomeric species whereas the dimer was only 80% active. The results suggest that a dimeric structure is not required for manifestation of amphiphile dependency of membrane-bound acetylcholinesterase from human erythrocytes. Furthermore, monomeric enzyme appears to be more easily inserted into phospholipid bilayers than the dimeric species.

  9. Propriedades químicas e de pasta dos amidos de trigo e milho fosforilados Chemical and past properties of wheat and maize starches phosphorilads

    Directory of Open Access Journals (Sweden)

    Williams Pereira Batista

    2010-03-01

    Full Text Available Os amidos de trigo e milho foram fosforilados com tripolifosfato de sódio (TPS em 4 diferentes níveis de adição. As viscosidades máximas da pasta de trigo aumentaram e as temperaturas de pasta diminuíram à medida que cresceram os graus de substituição de grupos fosfato, enquanto que, para o amido de milho, as viscosidades máximas aumentaram e as temperaturas de pasta mantiveram-se constantes. Os amidos fosforilados (amido/água 1:10 foram submetidos à cocção (100,0 ºC/1,0 minuto, secagem (40,0 ºC/~4,0% de umidade e moagem (diâmetro de partícula, Φ = 0,149 mm para determinar o teor de amido resistente (AR. Para o menor grau de substituição de grupos fosfato no amido de trigo (0,0029, foi encontrado um teor de amido resistente de 30,46% e no amido de milho de 24,36%. Para o maior grau de substituição no amido de trigo (0,0127, foi encontrado um teor de AR de 46,69%, enquanto para o amido de milho, 28,40%. O aumento do grau de substituição, em ambos os casos, parece induzir um aumento no teor de amido resistente, e a fosforilação com TPS mostrou ser um excelente método para produzir quantidades significativas de amido resistente tanto no amido de trigo como no amido de milho.Wheat and maize starches were phosphorylated with sodium tripolyphosphate (TPS at 4 different levels of addition. The maximum viscosities of the wheat doughs formed were increased and the dough temperatures decreased as the degrees of substitution of phosphate groups were increased; while for the maize starch the viscosities were increased and the dough temperatures remained constant. The phosphorylated starches (starch/water, 1:10 were subjected to cooking (100 ºC/1 minute, followed by drying (40 ºC/~ 4.0 per cent moisture and milling (particle diameter, Φ = 0.149 mm to determine the resistant starch (RS content. For the lowest degree of substitution of phosphate groups in wheat starch (0.0029, resistant starch content of 30.46 per cent was found

  10. Poly-amido-saccharides: synthesis via anionic polymerization of a β-lactam sugar monomer.

    Science.gov (United States)

    Dane, Eric L; Grinstaff, Mark W

    2012-10-01

    Enantiopure poly-amido-saccharides (PASs) with a defined molecular weight and narrow dispersity are synthesized using an anionic ring-opening polymerization of a β-lactam sugar monomer. The PASs have a previously unreported main chain structure that is composed of pyranose rings linked through the 1- and 2-positions by an amide with α-stereochemistry. The monomer is synthesized in one-step from benzyl-protected D-glucal and polymerized using mild reaction conditions to give degrees of polymerization ranging from 25 to >120 in high yield. Computational modeling reveals how the monomer's structure and steric bulk affect the thermodynamics and kinetics of polymerization. Protected and deprotected polymers and model compounds are characterized using a variety of methods (NMR, GPC, IR, DLS, etc.). On the basis of circular dichroism, the deprotected polymer possesses a regular secondary structure in aqueous solution, which agrees favorably with the prediction of a helical structure using molecular modeling. Furthermore, we provide evidence suggesting that the polymers bind the lectin concanavalin A at the same site as natural carbohydrates, showing the potential of these polymers to mimic natural polysaccharides. PASs offer the advantages associated with synthetic polymers, such as greater control over structure and derivitization. At the same time, they preserve many of the structural features of natural polysaccharides, such as a stereochemically regular, rigid pyranose backbone, that make natural carbohydrate polymers important materials both for their unique properties and useful applications.

  11. The comparison between carboxyl, amido and hydroxy group in influencing electrorheological performance

    Science.gov (United States)

    Li, Huo; Li, Jun-Ran; Liao, Fu-Hui

    2011-03-01

    Three kinds of electrorheological (ER) materials with carboxyl, amido and hydroxyl group, respectively, were synthesized by a simple adsorption method. The powder of silicon dioxide as a substrate of the materials, as well as terephthalic acid [ p-C6H4(COOH)2, abbr.: phen-COOH], p-phenylenediamine [ p-C6H4(NH2)2, abbr.: phen-NH2] and hydroquinone [ p-C6H4(OH)2, abbr.: phen-OH] were chosen as starting materials. The ER properties of suspensions of the materials in silicon oil were studied. The suspension of the material adsorbing phen-COOH reveals the highest ER activity, the relative shear stress of the suspension (25 wt%), τr(=τE/τ0, τE and τ0 are the shear stresses at electric field strengths of E=4.2 and 0 kV/mm, respectively), reaches 220 under a DC electric field at a shear rate of 14.5 s-1. The shear stress of the suspension of the material adsorbing phen-NH2 is the largest at an high electric field strength. The ER activity of the material adsorbing phen-OH is the lowest among the three materials. The molecule structure is an importance factor in influencing ER performance of the materials for similar compounds with different polar function groups. The relationship between the ER activity and dielectric property of the materials was discussed.

  12. Photoluminescent hyperbranched poly(amido amine) containing β-cyclodextrin as a nonviral gene delivery vector.

    Science.gov (United States)

    Chen, Yan; Zhou, Linzhu; Pang, Yan; Huang, Wei; Qiu, Feng; Jiang, Xulin; Zhu, Xinyuan; Yan, Deyue; Chen, Qun

    2011-06-15

    Hyperbranched poly(amido amine)s (HPAAs) containing different amounts of β-cyclodextrin (β-CD) (HPAA-CDs) were synthesized in one-pot by Michael addition copolymerization of N,N'-methylene bisacrylamide, 1-(2-aminoethyl)piperazine, and mono-6-deoxy-6-ethylenediamino-β-CD. In comparison to pure HPAA, the fluorescence intensity of HPAA-CDs was enhanced significantly while the cytotoxicity became lower. Ascribed to plenty of amino groups and strong photoluminescence, HPAA-CDs could be used as nonviral gene delivery vectors, and the corresponding gene transfection was evaluated. The experimental results indicated that HPAA-CDs condensed the plasmid DNA very well. By utilizing the fluorescent properties of HPAA-CDs, the cellular uptake and gene transfection processes were tracked by flow cytometry and confocal laser scanning microscopy without any fluorescent labeling. The transfection efficiencies of HPAA-CDs were similar to that of pure HPAA. In addition, the inner cavities of β-CDs in HPAA-CDs could be used to encapsulate drugs through host--guest interaction. Therefore, the HPAA-CDs may have potential application in the combination of gene therapy and chemotherapy.

  13. Monolayers of poly(amido amine) dendrimers on mica - In situ streaming potential measurements.

    Science.gov (United States)

    Michna, Aneta; Adamczyk, Zbigniew; Sofińska, Kamila; Matusik, Katarzyna

    2017-01-01

    The deposition of poly(amido amine) dendrimers on mica at various pHs was studied by the atomic force microscopy (AFM) and in situ streaming potential measurements. Bulk characteristics of dendrimers were acquired by using the dynamic light scattering (DLS) and the laser Doppler velocimetry (LDV). The hydrodynamic radius derived from DLS measurements was 5.2nm for the ionic strength of 10(-2)M and pH range 4-10. The electrophoretic mobility, the zeta potential and the number of electrokinetic charges per molecule were derived as a function of pH from the LDV measurements. It was revealed that the dendrimers are positively charged for pH up to 10. This promoted their deposition on negatively charged mica substrate whose kinetics was quantitatively evaluated by direct AFM imaging and streaming potential measurements interpreted in terms of the electrokinetic model. The desorption kinetics of dendrimers under flowing conditions from monolayers of various coverage was also studied. It was revealed that dendrimer deposition was partially reversible for pH above 5.8. The acid-base properties of the dendrimer monolayers deposited on mica were characterized.

  14. Amido resistente: características físico-químicas, propriedades fisiológicas e metodologias de quantificação

    Directory of Open Access Journals (Sweden)

    Walter Melissa

    2005-01-01

    Full Text Available Encontrado em diversos alimentos, o amido é a mais importante fonte de carboidratos da dieta. Potencialmente digerível pelas enzimas no trato gastrintestinal, é absorvido na forma de glicose no intestino delgado. Apesar disso, quantidade significativa de amido pode escapar a esta digestão, alcançando o cólon, onde é fermentado pela flora bacteriana. Esta fração, conhecida como amido resistente, tem sido intensamente estudada nos últimos anos devido aos potenciais benefícios à saúde humana. Vários métodos são utilizados para a determinação do amido resistente. Porém, nenhum é de aceitação unânime, uma vez que apresentam diferenças importantes nos protocolos e nos resultados obtidos. Neste contexto, o presente trabalho visa fornecer subsídios para um melhor entendimento sobre as características físico-químicas, propriedades metabólicas e fisiológicas, bem como, sobre as variações nas metodologias existentes para a determinação do amido resistente.

  15. A monomeric variant of insulin degrading enzyme (IDE loses its regulatory properties.

    Directory of Open Access Journals (Sweden)

    Eun Suk Song

    Full Text Available BACKGROUND: Insulin degrading enzyme (IDE is a key enzyme in the metabolism of both insulin and amyloid beta peptides. IDE is unique in that it is subject to allosteric activation which is hypothesized to occur through an oligomeric structure. METHODOLOGY/PRINCIPAL FINDINGS: IDE is known to exist as an equilibrium mixture of monomers, dimers, and higher oligomers, with the dimer being the predominant form. Based on the crystal structure of IDE we deleted the putative dimer interface in the C-terminal region, which resulted in a monomeric variant. Monomeric IDE retained enzymatic activity, however instead of the allosteric behavior seen with wild type enzyme it displayed Michaelis-Menten kinetic behavior. With the substrate Abz-GGFLRKHGQ-EDDnp, monomeric IDE retained approximately 25% of the wild type activity. In contrast with the larger peptide substrates beta-endorphin and amyloid beta peptide 1-40, monomeric IDE retained only 1 to 0.25% of wild type activity. Unlike wild type IDE neither bradykinin nor dynorphin B-9 activated the monomeric variant of the enzyme. Similarly, monomeric IDE was not activated by polyphosphates under conditions in which the activity of wild type enzyme was increased more than 50 fold. CONCLUSIONS/SIGNIFICANCE: These findings serve to establish the dimer interface in IDE and demonstrate the requirement for an oligomeric form of the enzyme for its regulatory properties. The data support a mechanism where the binding of activators to oligomeric IDE induces a conformational change that cannot occur in the monomeric variant. Since a conformational change from a closed to a more open structure is likely the rate-determining step in the IDE reaction, the subunit induced conformational change likely shifts the structure of the oligomeric enzyme to a more open conformation.

  16. Efeito da acidificação nas propriedades físico-químicas e funcionais do amido de sementes de manga (Mangifera indica L., variedade Tommy Atkins

    Directory of Open Access Journals (Sweden)

    Marianne Louise Marinho Mendes

    2015-06-01

    Full Text Available No processamento industrial da manga, os subprodutos, caroço e casca são, normalmente, descartados sem o devido aproveitamento. O objetivo deste trabalho foi investigar as características físico-químicas e funcionais dos amidos nativo e acidificado do caroço (amêndoa de manga, da variedade Tommy Atkins, pesquisando uma nova fonte de amido e formas de melhorá-la e contribuir para a utilização de resíduos da indústria alimentícia. As amêndoas foram retiradas manualmente dos caroços de manga e procedeu-se a extração do amido. O amido nativo foi acidificado, sendo o agente promotor da modificação o ácido clorídrico. Verificou-se a composição química do amido nativo. Determinaram-se também as propriedades funcionais e de pasta do amido nativo e do acidificado. Para a composição centesimal, o amido nativo apresentou 71,56% de amido, 7,30% de lipídeos e 5,6% de proteínas. Os amidos nativo e acidificado demonstraram baixa resistência à elevação da temperatura, com intumescimento máximo a 75 oC, sendo seus valores 9,395 e 6,861 g/g, respectivamente. A solubilidade mostrou-se crescente, à medida que houve elevação da temperatura, sendo seu valor máximo 48,03% para o amido acidificado. O amido nativo expôs maior capacidade de absorção de água, óleo e claridade da pasta. O referido amido ainda apresentou maior pico de viscosidade, viscosidade mínima, quebra de viscosidade, viscosidade final, retrogradação e temperatura de pasta do que os do amido acidificado. O amido nativo pode ser indicado para compor sopas desidratadas e produtos cárneos, enquanto o acidificado pode ser usado em alimentos congelados e refrigerados e na indústria de balas.

  17. Propriedades físico-químicas do amido de aveia da variedade brasileira IAC 7 Physicochemical properties of IAC 7 oat starch from Brazilian cultivars

    OpenAIRE

    2009-01-01

    Este estudo caracterizou o amido de aveia da variedade IAC-7 quanto às suas características químicas, reológicas, funcionais e térmicas. O amido de aveia apresentou 1,36% de lipídios, 32,23% de amilose e baixa capacidade retrogradante (9,19% após 30 dias de armazenagem). Embora o amido de aveia tenha apresentado alto teor de amilose, sua baixa retrogradação pode ser devida à presença dos lipídios que, por impedimento estérico, dificultariam a reaproximação das cadeias poliméricas. O comportam...

  18. Processamento de amido de milho em câmara de mistura Peocessing of corn starch in an internal mixer

    Directory of Open Access Journals (Sweden)

    Marcia C. Silva

    2004-06-01

    Full Text Available Misturas de amido de milho e água nas proporções 70:30, 80:20 e 90:10% (p/p foram submetidas a processamento a 90°C, sob diferentes velocidades de rotação (20, 40, 80 e 100rpm, em câmara de mistura Rheomix 600 equipada com rotores do tipo "roller". A influência do teor de água e da velocidade de rotação dos rotores no processamento do amido de milho foi investigada por meio de curvas de torque e de temperatura fornecidas pelo reômetro de torque Rheocord 9000. Análises em Analisador Rápido de Viscosidade e por microscopia óptica de luz polarizada foram realizadas, a fim de complementar as informações registradas pelas curvas de torque e de temperatura. Os resultados mostraram que o teor de água e a rotação empregada no processamento exercem influência significativa nas características do amido processado. Os menores teores de água (10 e 20% p/p e as velocidades de rotação mais elevadas (80 e 100rpm contribuíram para a maior degradação do amido. Nas misturas com teor de água de 30% (p/p, sob as velocidades de rotação empregadas, a função plastificante da água contribuiu para minimizar o efeito do cisalhamento, já que a degradação do amido não foi observada. Nesses casos, a estrutura granular do amido foi preservada em grande parte durante o processamento.Corn starch/water mixtures at compositions of 70:30, 80:20 and 90:10 (w/w % were submitted to processing at 90ºC and different rates (20, 40, 80 and 100rpm in an internal mixer (Rheomix 600, equipped with counter-rotating roller type rotors. The effect of the water content and of the rotation rate on the starch processing was investigated by torque and temperature curves given by the in-line Rheocord 9000 torque rheometer. Viscosity measurements, carried out in a Rapid Visco Analyser (RVA, and optical microscopy analysis were performed on the processed samples to complement the rheometry data. The results indicated that the water content and the rotation rate

  19. Inorganic base-catalyzed formation of antivirally active N-substituted benzamides from α-amido sulfones and N-nucleophile

    Directory of Open Access Journals (Sweden)

    Wang Zhenchao

    2011-05-01

    Full Text Available Abstract Background Heteronucleophiles as well as carbanionic reagents can be used to react with α-amido sulfones, thus giving the opportunity to prepare a large array of amino derivatives. Since, novel 1,3,4-oxadiazole-2-thiol derivatives can serve as potent nucleophiles, we employed 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the nucleophilic source of nitrogen in the reaction with α-amido sulfones. Results A series of N-substituted benzamides bearing 1,3,4-oxadiazol unit were prepared for the first time by the reaction of in situ generated protected imine from α-amido sulfones with 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophile. Some of the synthesized products displayed favourable antiviral activity against cucumber mosaic virus (CMV in preliminary antiviral activity tests. The title compounds 5c, 5o and 5r revealed curative activity of 42.2%, 48.7% and 40.5%, respectively against CMV (inhibitory rate compared to the commercial standard Ningnanmycin (53.4% at 500 μg/mL. Conclusion A practical synthetic route to N-benzoyl-α-amido sulfones by the reaction of 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophiles with in situ generated protected imine from N-benzoyl-α-amido sulfones is presented. The reaction catalyzed by an inorganic base has considerable significance to exploit the potential of α-amido sulfones in organic synthesis.

  20. Propriedades físico-químicas do amido de aveia da variedade brasileira IAC 7 Physicochemical properties of IAC 7 oat starch from Brazilian cultivars

    Directory of Open Access Journals (Sweden)

    Melicia Cintia Galdeano

    2009-12-01

    Full Text Available Este estudo caracterizou o amido de aveia da variedade IAC-7 quanto às suas características químicas, reológicas, funcionais e térmicas. O amido de aveia apresentou 1,36% de lipídios, 32,23% de amilose e baixa capacidade retrogradante (9,19% após 30 dias de armazenagem. Embora o amido de aveia tenha apresentado alto teor de amilose, sua baixa retrogradação pode ser devida à presença dos lipídios que, por impedimento estérico, dificultariam a reaproximação das cadeias poliméricas. O comportamento reológico das pastas de amido de aveia foi caracterizado como sendo pseudoplático. A baixa temperatura de gelatinização (64,71 °C do amido de aveia também pode estar relacionada ao maior teor de lipídio deste amido.This study characterized the chemical, rheological, functional and thermal properties of oat starch of IAC-7 variety. The oat starch showed 1.36% of lipids, 32.23% of amylose and low retrogradation capacity (9.19% after 30 days of storage. Although the oat starch has presented high amylose content, its low retrogradation may be due to the presence of lipids that by steric impediment could make it difficult for the polymeric chains to approach. The rheological behavior of oat starch was characterized as pseudoplastic. The low gelatinization temperature (64.71 °C of the starch may be related to its higher lipid content.

  1. Espalhamento e secagem de filme de amido-glicerol-fibra preparado por "tape-casting"

    Directory of Open Access Journals (Sweden)

    Jaqueline Oliveira de Moraes

    2014-02-01

    Full Text Available O objetivo deste trabalho foi avaliar processos de espalhamento e secagem de filme de amido-glicerol-fibras de celulose, preparado por "tape-casting". O espalhamento da suspensão foi avaliado a 50, 150 e 250 cm min-1, seguido de secagem em estufa com circulação forçada de ar, a 40 ou 70ºC; avaliou-se também o espalhamento da suspensão a 150 cm min-1, seguido da secagem do filme sobre suporte de "tape-casting" a 22ºC e 60% de umidade relativa, com velocidades do ar de 4, 6 e 8 m s-1 no túnel de secagem. Ensaios reológicos mostraram que o espalhamento das suspensões a temperaturas inferiores a 50ºC apresentou módulo de elasticidade superior ao módulo viscoso, em todo o espectro de frequências de oscilação. As microscopias mostraram filmes secos a 40 e 70ºC sem defeitos de formação, e cujas propriedades mecânicas não diferiam. A velocidade de espalhamento e a do ar não modificam o tempo de secagem nem as propriedades dos filmes. O tempo de secagem pode ser reduzido para aproximadamente duas horas, o que é importante para a produção dos filmes em larga escala.

  2. Desenvolvimento de novas tecnologias para produção de xarope de glicose a partir do amido

    OpenAIRE

    Freitas, Aline Costa de [UNESP

    2012-01-01

    As amilases são enzimas que catalisam a hidrólise do amido, dentre as quais se destaca a α-amilase, a β-amilase e a glicoamilase. Apresentam grande importância biotecnológica devido sua aplicação em vários processos industriais, principalmente alimentício. Podem ser obtidas de plantas, animais e microorganismos, no entanto, enzimas microbianas encontram maior demanda industrial. Além da importância econômica destas enzimas, novas metodologias têm sido desenvolvidas com resíduos como substrato...

  3. Electrochemical synthesis of polyaniline/poly(2-acryl-amido-2-methyl-1-propane-sulfonic acid) composite

    Energy Technology Data Exchange (ETDEWEB)

    Lapkowski, M. (Inst. of Physical Chemistry and Technology of Polymers, Silesian Technical Univ., Gliwice (Poland))

    1993-03-22

    Conducting polyaniline/poly(2-acryl-amido-2-methyl-1-propane sulfonic acid) (PANi/PAMPS) composite films were synthesized electrochemically on platinum electrodes using a 10% aqueous PAMPS solution as the electrolyte. The electrochemical properties of the resulting polymer are similar to those observed for polyaniline doped with classical non-polymeric anions. PANi/PAMPS exhibits high cycling stability within the potential range of the first redox couple, but it undergoes degradation when the potential range characteristic of the second redox couple is reached. The degradation occurs independently of the electrolytic medium (HCl or 10% aqueous PAMPS). (orig.)

  4. Synthesis of C-4 Substituted Amido Nicotine Derivatives via Copper(I)- and (II)-Catalyzed Cross-Coupling Reactions.

    Science.gov (United States)

    Zhu, Jiancheng; Enamorado, Monica F; Comins, Daniel L

    2016-11-18

    The syntheses of seven novel amido nicotine derivatives 12-18 from (S)-nicotine are presented. (S)-Nicotine and (S)-6-chloronicotine derivatives were cross-coupled with the corresponding amides 6-10 at the C-4 position of the pyridine ring via copper(I)-mediated reactions. Derivatives 16-18 were also obtained via copper(II)-mediated reactions from (S)-nicotine containing a C-4 boronic acid pinacol ester group. The optimization of reaction conditions for both routes provided a useful method for preparing C-4 amide-containing nicotine analogs.

  5. Diels-Alder Reactions of α-Amido Acrylates with N-Cbz-1,2-dihydropyridine and Cyclopentadiene.

    Science.gov (United States)

    Abas, Hossay; Frampton, Christopher S; Spivey, Alan C

    2016-10-21

    Thermal Diels-Alder reactions of α-amido acrylates with N-Cbz-1,2-dihydropyridine and cyclopentadiene have been explored to investigate the factors influencing the endo/exo selectivity. For the dihydropyridine, steric factors allowed the diastereoselectivity to be modulated to favor either endo- or exo-ester adducts. For cyclopentadiene, the endo-ester adducts were favored regardless of steric perturbation, although catalysis by bulky Lewis acids increased the proportion of exo-ester adducts in some cases. These Lewis acids were incompatible with the dihydropyridine diene as they induced its decomposition.

  6. 3-Alkyl- and 3-amido-isothiazoloquinolin-4-ones as ligands for the benzodiazepine site of GABAA receptors

    DEFF Research Database (Denmark)

    Nilsson, Jakob; Nielsen, Elsebet Østergaard; Liljefors, Tommy

    2012-01-01

    Based on a pharmacophore model of the benzodiazepine binding site of the GABA(A) receptors, developed with synthetic flavones and potent 3-carbonylquinolin-4-ones, 3-alkyl- and 3-amido-6-methylisothiazoloquinolin-4-ones were designed, prepared and assayed. The suggestion that the interaction...... interaction with the lipophilic pockets of the pharmacophore model. The most potent 3-alkyl derivative, 3-pentyl-6-methylisothiazoloquinolin-4-one, has an affinity (K(i) value) for the benzodiazepine binding site of the GABA(A) receptors of 13nM. However, by replacing the 3-pentyl with a 3-butyramido group...

  7. Anthocyanins and their variation in red wines I. Monomeric anthocyanins and their color expression.

    Science.gov (United States)

    He, Fei; Liang, Na-Na; Mu, Lin; Pan, Qiu-Hong; Wang, Jun; Reeves, Malcolm J; Duan, Chang-Qing

    2012-02-07

    Originating in the grapes, monomeric anthocyanins in young red wines contribute the majority of color and the supposed beneficial health effects related to their consumption, and as such they are recognized as one of the most important groups of phenolic metabolites in red wines. In recent years, our increasing knowledge of the chemical complexity of the monomeric anthocyanins, their stability, together with the phenomena such as self-association and copigmentation that can stabilize and enhance their color has helped to explain their color representation in red wine making and aging. A series of new enological practices were developed to improve the anthocyanin extraction, as well as their color expression and maintenance. This paper summarizes the most recent advances in the studies of the monomeric anthocyanins in red wines, emphasizing their origin, occurrence, color enhancing effects, their degradation and the effect of various enological practices on them.

  8. Anthocyanins and Their Variation in Red Wines I. Monomeric Anthocyanins and Their Color Expression

    Directory of Open Access Journals (Sweden)

    Chang-Qing Duan

    2012-02-01

    Full Text Available Originating in the grapes, monomeric anthocyanins in young red wines contribute the majority of color and the supposed beneficial health effects related to their consumption, and as such they are recognized as one of the most important groups of phenolic metabolites in red wines. In recent years, our increasing knowledge of the chemical complexity of the monomeric anthocyanins, their stability, together with the phenomena such as self-association and copigmentation that can stabilize and enhance their color has helped to explain their color representation in red wine making and aging. A series of new enological practices were developed to improve the anthocyanin extraction, as well as their color expression and maintenance. This paper summarizes the most recent advances in the studies of the monomeric anthocyanins in red wines, emphasizing their origin, occurrence, color enhancing effects, their degradation and the effect of various enological practices on them.

  9. B22 Glu Des-B30 Insulin: A Novel Monomeric Insulin

    Institute of Scientific and Technical Information of China (English)

    Hai-Juan DU; Jia-Hao SHI; Da-Fu CUI; You-Shang ZHANG

    2006-01-01

    Studies on monomeric insulin with reduced self-association are important in the development of insulin pharmaceutical preparations with rapid hypoglycemic action on patients with diabetes. Here we report a novel monomeric insulin, B22 Glu des-B30 insulin, prepared from a single chain insulin precursor with B22 Arg mutated to Glu, which was expressed in Pichia pastoris and converted to B22 Glu des-B30 insulin by tryptic digestion. It still retains 50% of the in vivo biological activity of porcine insulin and does not form a dimer even at a concentration of 10 mg/ml, showing that B22 Glu plays a key role in reducing the selfassociation of the insulin molecule without greatly reducing its biological activity. This novel monomeric insulin might have potential applications in the clinic.

  10. Adição de inulina em géis de amido e leite utilizando planejamento experimental de misturas

    OpenAIRE

    Lobato,Luciana Pereira; Benassi,Marta de Toledo; Grossmann,Maria Victoria Eiras

    2012-01-01

    O objetivo deste estudo foi investigar o efeito combinado de inulina, amido e leite nas características texturais de géis e de propriedades de pastas empregando o planejamento experimental de misturas. Foram avaliados o perfil viscoamilográfico e a firmeza dos géis. Em todos os parâmetros avaliados, os modelos ajustados mostraram-se influenciados pela presença de inulina, amido e leite, assim como de algumas interações desses ingredientes. A viscosidade máxima e a viscosidade final foram infl...

  11. Valor nutritivo de rações compostas de fontes de amido e de nitrogênio com alta e baixa degradabilidade ruminal

    OpenAIRE

    Zeoula,Lúcia Maria; Prado,Ivanor Nunes do; Cecato, Ulysses; Branco,Antonio Ferriani; Damasceno,Júlio Cesar; Watanabe,Marcio Munemori; Fridrich,Daniele; Biliero,Conrado Luís

    1999-01-01

    O objetivo deste estudo foi avaliar o consumo, o coeficiente de digestibilidade aparente (CDA), o balanço de nitrogênio, o pH e a concentração de nitrogênio amoniacal no líquido ruminal de ovinos. Os animais foram alimentados com rações compostas de concentrados com diferentes degradabilidade ruminal das frações amido e nitrogênio das seguintes fontes: amido (AM) de alta (triticale) e baixa (milho) degradabilidade ruminal combinada com fontes de nitrogênio (N) de alta (farelo de canola + uréi...

  12. Preparation of polyelectrolyte complex nanoparticles of chitosan and poly(2-acry1amido-2-methylpropanesulfonic acid) for doxorubicin release.

    Science.gov (United States)

    Zhang, Liping; Wang, Jie; Ni, Caihua; Zhang, Yanan; Shi, Gang

    2016-01-01

    A new kind of polyelectrolyte complex (PEC) based on cationic chitosan (CS) and anionic poly(2-acry1amido-2-methylpropanesulfonic acid) (PAMPS) was prepared using a polymer-monomer pair reaction system. Chitosan was mixed with 2-acry1amido-2-methylpropanesulfonic acid) (AMPS) in an aqueous solution, followed by polymerization of AMPS. The complex was formed by electrostatic interaction of NH3(+) groups of CS and SO3(-) groups of AMPS, leading to a formation of complex nanoparticles of CS-PAMPS. A series of nanoparticles were obtained by changing the weight ratio of CS to AMPS, the structure and properties of nanoparticles were investigated. It was observed that the nanoparticles possessed spherical morphologies with average diameters from 255 nm to 390 nm varied with compositions of the nanoparticles. The nanoparticles were used as drug vehicles for doxorubicin, displaying relative high drug loading rate and encapsulation rate. The vitro release profiles revealed that the drug release could be controlled by adjusting pH of the release media. The nanoparticles demonstrated apparent advantages such as simple preparation process, free of organic solvents, size controllable, good biodegradability and biocompatibility, and they could be potentially used in drug controlled release field.

  13. Physical characteristics of extruded cassava starch Características físicas de amido de mandioca extrusado

    Directory of Open Access Journals (Sweden)

    Magali Leonel

    2009-08-01

    Full Text Available Considering the importance of cassava starch for Brazilian industries, the current work aimed at evaluating the effects of extrusion parameters on the physical characteristics, mainly viscosity properties of extruded cassava starch. A factorial central composite design (2³ with three independent variables and the response surface methodology were used to evaluate the results of expansion index, specific volume, water absorption index, water solubility index, color and paste properties, according to the variations in the moisture content, barrel temperature and screw speed. Results indicated that barrel temperature influenced the expansion index, specific volume, water absorption index, all the color parameters, the initial viscosity, peak and final viscosity. Feed moisture influenced the specific volume, color parameters, final viscosity and retrogradation. The screw speed had effects on water absorption index, color components as well as on the final viscosity and retrogradation of extruded starch. High moisture, low screw speed and intermediate temperature provided lower starch degradation, which is desirable for pre-cooked starch.Considerando a importância do amido de mandioca para as indústrias brasileiras, este trabalho teve por objetivo avaliar os efeitos de parâmetros de extrusão sobre as características físicas e propriedades de pasta do amido de mandioca extrusado. Foi utilizado o delineamento fatorial do tipo central composto rotacional com três variáveis independentes (2³ e a metodologia de superfície de resposta para avaliar os resultados de índice de expansão, volume específico, índice de absorção de água, índice de solubilidade em água, cor e propriedades de pasta, de acordo com as variações de umidade, temperatura de extrusão e rotação da rosca. A temperatura de extrusão influenciou o índice de expansão, volume específico, índice de absorção de água, todos os parâmetros de cor e a viscosidade

  14. A novel method to highly versatile monomeric PNA building blocks by multi component reactions

    NARCIS (Netherlands)

    Dömling, Alexander; Chi, Kai-Zu; Barrère, Mathieux

    1999-01-01

    A novel approach to monomeric PNA building blocks by a solution phase Ugi multi component reaction (MCR) is described. The reaction is easily performed in 96 well plates. The products precipitate from the reaction solution and are thus obtained in high yields and purity. Those products are not amena

  15. Monomeric G-proteins as signal transducers in airway physiology and pathophysiology

    NARCIS (Netherlands)

    Schaafsma, Dedmer; Roscioni, Sara S.; Meurs, Herman; Schmidt, Martina

    2008-01-01

    Monomeric G-proteins, also referred to as small GTPases, function as biological hubs being activated by extracellular stimuli and regulate downstream signalling events, which result in different cellular responses. The importance of these mechanisms is mirrored by the fact that several pathological

  16. Self-healing mechanism based on dispersed solid particles of various monomeric bismaleimides

    NARCIS (Netherlands)

    Turkenburg, D.H.; Fischer, H.R.

    2016-01-01

    In view of self-healing materials for high temperature applications we have studied the use of solid monomeric bismaleimide particles as embedded self-healing component dispersed in a host material. Below the self-healing activation temperature, bismaleimides remain inert while above it they may rap

  17. Monomeric red fluorescent protein variants used for imaging studies in different species

    NARCIS (Netherlands)

    Mueller-Taubenberger, Annette; Vos, Michel J.; Boettger, Angelika; Lasi, Margherita; Lai, Frank P. L.; Fischer, Markus; Rottner, Klemens

    2006-01-01

    Fluorescent proteins have proven to be excellent tools for live-cell imaging studies. In addition to green fluorescent protein (GFP) and its variants, recent progress was achieved in the development of monomeric red fluorescent proteins (mRFPs) that show improved properties in respect to maturation

  18. Monomeric and dendritic second generation Grubbs- and Hoveyda-Grubbs-type catalysts for olefin metathesis Metallodendrimers Special Issue

    NARCIS (Netherlands)

    Pijnenburg, Niels J M; Tomás-Mendivil, Eder; Mayland, Kimberley E.; Kleijn, Henk; Lutz, Martin; Spek, Anthony L.; Van Koten, Gerard; Klein Gebbink, Bert

    2014-01-01

    The synthesis and characterization of monomeric and dendritic Grubbs II and Hoveyda-Grubbs II-based complexes are reported. These complexes were synthesized via a route based on the connection of monomeric or dendritic N-alkyl-N′-mesitylimidazol-2-ylidene pre-ligands to Grubbs I or Hoveyda-Grubbs I

  19. Efeito do processamento e das condições ambientais nas propriedades de materiais biodegradáveis de amido de aveia

    Directory of Open Access Journals (Sweden)

    Melicia Cintia Galdeano

    2014-01-01

    Full Text Available A característica hidrofílica dos biomateriais a base de amido resulta em alta instabilidade diante de diferentes condições ambientais. O amido de aveia, por possuir um conteúdo maior de lipídios em relação a outros amidos, torna-se uma fonte interessante, uma vez que a hidrofobicidade aumentada pode atuar reduzindo sua capacidade de sorção de umidade. O objetivo do trabalho foi investigar o comportamento de filmes e laminados de amido de aveia, produzidos por casting e extrusão, respectivamente, plastificados com glicerol, sorbitol e ureia e armazenados em diferentes condições de umidade relativa. Mesmo com a presença do lipídio nativo, os materiais ainda mostraram instabilidade diante do aumento da umidade relativa de armazenagem, sendo observado um decréscimo na força e um aumento na deformação nos testes de perfuração. Em geral os biomateriais plastificados com glicerol apresentaram maior capacidade de sorção de água. O sorbitol foi o plastificante mais efetivo, pois produziu materiais com propriedades mecânicas similares aos outros plastificantes mesmo sendo usado em menor concentração molar. O processo de extrusão resultou em materiais finais com estruturas mais abertas e fragmentadas.

  20. Redução da hidrofilicidade de filmes biodegradáveis à base de amido por meio de polimerização por plasma

    Directory of Open Access Journals (Sweden)

    Thiré Rossana M. S. M.

    2004-01-01

    Full Text Available Devido ao baixo custo de produção e excelente biodegradabilidade, o amido constitui-se em matéria-prima promissora para a produção de plásticos biodegradáveis. No entanto, a grande hidrofilicidade dos filmes à base de amido representa uma séria limitação tecnológica à sua comercialização, uma vez que as propriedades dos filmes são afetadas pela variação da umidade relativa do ar durante a sua estocagem ou o seu uso. Neste trabalho, filmes de amido termoplástico foram recobertos com uma fina camada protetora polimérica gerada por intermédio da tecnologia de plasma frio. 1-Buteno e 1,3-butadieno foram utilizados como monômeros para a polimerização por plasma. Os filmes recobertos apresentaram uma redução de até 80% na absorção de água e aumento do ângulo de contato em relação à água. Estes resultados indicaram uma redução significativa na natureza hidrofílica do material à base de amido após o recobrimento.

  1. Monomeric yeast PCNA mutants are defective in interacting with and stimulating the ATPase activity of RFC.

    Science.gov (United States)

    Ionescu, Costin N; Shea, Kathleen A; Mehra, Rajendra; Prundeanu, Lucia; McAlear, Michael A

    2002-10-29

    Yeast PCNA is a homo-trimeric, ring-shaped DNA polymerase accessory protein that can encircle duplex DNA. The integrity of this multimeric sliding DNA clamp is maintained through the protein-protein interactions at the interfaces of adjacent subunits. To investigate the importance of trimer stability for PCNA function, we introduced single amino acid substitutions at residues (A112T, S135F) that map to opposite ends of the monomeric protein. Recombinant wild-type and mutant PCNAs were purified from E. coli, and they were tested for their properties in vitro. Unlike the stable wild-type PCNA trimers, the mutant PCNA proteins behaved as monomers when diluted to low nanomolar concentrations. In contrast to what has been reported for a monomeric form of the beta clamp in E. coli, the monomeric PCNAs were compromised in their ability to interact with their associated clamp loader, replication factor C (RFC). Similarly, monomeric PCNAs were not effective in stimulating the ATPase activity of RFC. The mutant PCNAs were able to form mixed trimers with wild-type subunits, although these mixed trimers were unstable when loaded onto DNA. They were able to function as weak DNA polymerase delta processivity factors in vitro, and when the monomeric PCNA-41 (A112T, S135F double mutant) allele was introduced as the sole source of PCNA in vivo, the cells were viable and healthy. These pol30-41 mutants were, however, sensitive to UV irradiation and to the DNA damaging agent methylmethane sulfonate, implying that DNA repair pathways have a distinct requirement for stable DNA clamps.

  2. Digestibilidade aparente de dietas contendo diferentes níveis de amido para coelhos em crescimento Apparent digestibility of diets with different starch levels for growing rabbits

    Directory of Open Access Journals (Sweden)

    Alex Martins Varela de Arruda

    2000-06-01

    Full Text Available Com o objetivo de avaliar a influência do amido dietético sobre a digestibilidade aparente dos nutrientes, para coelhos em fase de crescimento, quatro dietas experimentais foram elaboradas de forma a conter níveis crescentes de amido de milho (23, 28, 33 e 38% de amido total na base da matéria seca (MS, os quais foram fornecidas a 20 coelhos da raça Nova Zelândia Branco, distribuídos em gaiolas de metabolismo individuais, segundo delineamento inteiramente casualizado. Os resultados obtidos demonstraram efeito linear crescente para os coeficientes de digestibilidade aparente da MS, matéria orgânica (MO, fibra em detergente neutro (FDN e amido, à medida que aumentou o nível de amido dietético nas dietas experimentais. O nível de 38% de amido dietético proporcionou, portanto, o melhor coeficiente de digestibilidade para o amido (87,26%. Não foram observadas diferenças para os coeficientes de digestibilidade aparente da proteína bruta (PB, energia bruta (EB e fibra em detergente ácido (FDA, em relação aos diferentes níveis de amido nas dietas experimentais. No entanto, para o teor de extrato etéreo (EE, foi verificado melhor aproveitamento (89,46% para os animais alimentados com a dieta contendo 23% de amido. Os coelhos foram eficientes em digerir o amido de milho, quando este apresentou alta participação na porção carboidrato total da dieta.With the objective to evaluate the effect of dietetic starch on the nutrients apparent digestibility for rabbits in the growing phase, four experimental diets were formulated to contain increasing corn starch levels (23, 28, 33 and 38% total starch levels in dry matter [DM] basis. A total of 20 White New Zealand rabbits were allotted to metabolism cages in a completely randomized design. The results showed a crescent linear effect for the coefficients of apparent digestibility for DM, organic matter (OM, neutral detergent fiber (NDF and starch as the dietary starch level increased in

  3. AMIDO E HIPOCLORITO DE SÓDIO NO ENRAIZAMENTO IN VITRO DO ABACAXIZEIRO ‘GOLD’ E SEUS EFEITOS NA ACLIMATIZAÇÃO

    Directory of Open Access Journals (Sweden)

    RODRIGO DA SILVA OLIVEIRA

    2015-06-01

    Full Text Available Este trabalho teve como objetivo avaliar a substituição total ou parcial do ágar por amidos de milho e mandioca e da esterilizaçãofísica em autoclave pela esterilização química com hipoclorito de sódio (NaClO no desenvolvimento de mudas deabacaxizeiro ‘Gold’ (Ananas comosus. Como agentes geleificantes,foram utilizados: M1: ágar (6,0 g L-1;M2: amido de milho (60,0 g L-1; M3: ágar (3,0 g L-1 + amido de milho (30,0 g L-1, e M4: ágar (3,0 g L-1 + amido de mandioca (30,0 g L-1. As esterilizações foram feitas por meio da autoclavagem a 121°C e da utilização de soluções de NaClO nas concentrações de 0,003% para o enxágue das vidrarias e 0,0003% para adição ao meio de cultivo. Após um mês de cultivo in vitro, não houve influência negativa do NaClO e dos agentes geleificantes no enraizamento das brotações para a maioria dos parâmetros avaliados. As mudas produzidas in vitro foram levadas para aclimatização em casa de vegetação, por 90 dias. Na aclimatização, as mudas oriundas dos tratamentos com esterilização química não diferiram das oriundas dos meios autoclavados em nenhum parâmetro avaliado, enquanto a combinação ágar + amido de milho proporcionou resultados inferiores entre os agentes geleificantes.

  4. Total allowable concentrations of monomeric inorganic aluminum and hydrated aluminum silicates in drinking water.

    Science.gov (United States)

    Willhite, Calvin C; Ball, Gwendolyn L; McLellan, Clifton J

    2012-05-01

    Maximum contaminant levels are used to control potential health hazards posed by chemicals in drinking water, but no primary national or international limits for aluminum (Al) have been adopted. Given the differences in toxicological profiles, the present evaluation derives total allowable concentrations for certain water-soluble inorganic Al compounds (including chloride, hydroxide, oxide, phosphate and sulfate) and for the hydrated Al silicates (including attapulgite, bentonite/montmorillonite, illite, kaolinite) in drinking water. The chemistry, toxicology and clinical experience with Al materials are extensive and depend upon the particular physical and chemical form. In general, the water solubility of the monomeric Al materials depends on pH and their water solubility and gastrointestinal bioavailability are much greater than that of the hydrated Al silicates. Other than Al-containing antacids and buffered aspirin, food is the primary source of Al exposure for most healthy people. Systemic uptake of Al after ingestion of the monomeric salts is somewhat greater from drinking water (0.28%) than from food (0.1%). Once absorbed, Al accumulates in bone, brain, liver and kidney, with bone as the major site for Al deposition in humans. Oral Al hydroxide is used routinely to bind phosphate salts in the gut to control hyperphosphatemia in people with compromised renal function. Signs of chronic Al toxicity in the musculoskeletal system include a vitamin D-resistant osteomalacia (deranged membranous bone formation characterized by accumulation of the osteoid matrix and reduced mineralization, reduced numbers of osteoblasts and osteoclasts, decreased lamellar and osteoid bands with elevated Al concentrations) presenting as bone pain and proximal myopathy. Aluminum-induced bone disease can progress to stress fractures of the ribs, femur, vertebrae, humerus and metatarsals. Serum Al ≥100 µg/L has a 75-88% positive predictive value for Al bone disease. Chronic Al

  5. Porous chitosan doped with graphene oxide as highly effective adsorbent for methyl orange and amido black 10B.

    Science.gov (United States)

    Wang, Ying; Xia, Guangmei; Wu, Cong; Sun, Jing; Song, Rui; Huang, Wei

    2015-01-22

    In the current study, porous chitosan aerogels doped with small amount of graphene oxide (CSGO aerogels) with high porosity (97.96-98.78%), extraordinarily high water absorption (5848-8917%) and low density (0.021-0.035 g cm(-3)) were prepared and used as adsorbents for two azo dyes methyl orange (MO) and amido black 10B (AB10B). The adsorption behavior of these CSGO aerogels and some influence factors such as pH value, graphene oxide (GO) loading, concentration of pollutants, as well as adsorption kinetics were studied. Specifically, the adsorption capacity for MO is 686.89 mg g(-1), the highest comparing with other publication results, and it is 573.47 mg g(-1) for AB10B. Since they are biodegradable, non-toxic, efficient, low-cost and easy to prepare, we believe that these porous CSGO aerogels will be a promising candidate for dye removal.

  6. Mechanism of Amido-Thiourea Catalyzed Enantioselective Imine Hydrocyanation: Transition State Stabilization via Multiple Non-Covalent Interactions

    Science.gov (United States)

    Zuend, Stephan J.

    2009-01-01

    An experimental and computational investigation of amido-thiourea promoted imine hydrocyanation has revealed a new and unexpected mechanism of catalysis. Rather than direct activation of the imine by the thiourea, as had been proposed previously in related systems, the data are consistent with a mechanism involving catalyst-promoted proton transfer from hydrogen isocyanide to imine to generate diastereomeric iminium/cyanide ion pairs that are bound to catalyst through multiple non-covalent interactions; these ion pairs collapse to form the enantiomeric α-aminonitrile products. This mechanistic proposal is supported by the observation of a statistically significant correlation between experimental and calculated enantioselectivities induced by eight different catalysts (P ≪ 0.01). The computed models reveal a basis for enantioselectivity that involves multiple stabilizing and destabilizing interactions between substrate and catalyst, including thiourea-cyanide and amide-iminium interactions. PMID:19778044

  7. Caracterização físico-química, reológica, morfológica e térmica dos amidos de milho normal, ceroso e com alto teor de amilose

    OpenAIRE

    Weber,Fernanda Hart; Collares-Queiroz, Fernanda Paula; Chang, Yoon Kil

    2009-01-01

    O objetivo do presente estudo foi avaliar os amidos de milho normal, ceroso e com alto teor de amilose, fabricados pela National Starch, por meio da determinação das suas características físico-químicas, morfológicas, térmicas e reológicas. O amido de milho com alto teor de amilose (AM) apresentou teor de amilose igual a 71%, sendo que os valores obtidos para o amido de milho normal (M) e o amido de milho ceroso (AP) foram de 27,8 e 1,8%, respectivamente. Traços de proteína e lipídios foram e...

  8. Monomeric carbohydrates production from olive tree pruning biomass: modeling of dilute acid hydrolysis.

    Science.gov (United States)

    Puentes, Juan G; Mateo, Soledad; Fonseca, Bruno G; Roberto, Inês C; Sánchez, Sebastián; Moya, Alberto J

    2013-12-01

    Statistical modeling and optimization of dilute sulfuric acid hydrolysis of olive tree pruning biomass has been performed using response surface methodology. Central composite rotatable design was applied to assess the effect of acid concentration, reaction time and temperature on efficiency and selectivity of hemicellulosic monomeric carbohydrates to d-xylose. Second-order polynomial model was fitted to experimental data to find the optimum reaction conditions by multiple regression analysis. The monomeric d-xylose recovery 85% (as predicted by the model) was achieved under optimized hydrolysis conditions (1.27% acid concentration, 96.5°C and 138 min), confirming the high validity of the developed model. The content of d-glucose (8.3%) and monosaccharide degradation products (0.1% furfural and 0.04% 5-hydroxymethylfurfural) provided a high quality subtract, ready for subsequent biochemical conversion to value-added products.

  9. The Roles of Monomeric GTP-Binding Proteins in Macroautophagy in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2014-10-01

    Full Text Available Autophagy is a cellular degradation process that sequesters components into a double-membrane structure called the autophagosome, which then fuses with the lysosome or vacuole for hydrolysis and recycling of building blocks. Bulk phase autophagy, also known as macroautophagy, controlled by specific Atg proteins, can be triggered by a variety of stresses, including starvation. Because autophagy relies extensively on membrane traffic to form the membranous structures, factors that control membrane traffic are essential for autophagy. Among these factors, the monomeric GTP-binding proteins that cycle between active and inactive conformations form an important group. In this review, we summarize the functions of the monomeric GTP-binding proteins in autophagy, especially with reference to experiments in Saccharomyces cerevisiae.

  10. Pentamethylcyclopentadienyl and bis(trimethylsilyl)amido complexes of the di- and trivalent lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Tilley, T.D.

    1982-03-01

    The reaction of the divalent iodides YbI/sub 2/ and EuI/sub 2/ with NaN(SiMe/sub 3/)/sub 2/ has provided pentane-soluble, monomeric derivatives of the divalent lanthanides. These compounds are isolated as the solvated species Eu(N(SiMe/sub 3/)/sub 2/)/sub 2/L/sub 2/ (L = thf or 1,2-dme), Yb(N(SiMe/sub 3/)/sub 2/)/sub 2/(thf)/sub 1/ /sub 5/ and Yb(N(SiMe/sub 3/)/sub 2/)/sub 2/L/sub 2/ (L = 1,2-dme or OEt/sub 2/), or as the sodium salts NaM(N(SiMe/sub 3/)/sub 2/)/sub 3/ (M = Eu or Yb). The pentamethylcyclopentadienyl ligand has been used to obtain trivalent derivatives of the type (C/sub 5/Me/sub 5/)/sub 2/MCl/sub 2/M'L/sub x/ (M = Nd, Sm or Yb; M' = Li or Na; L = OEt/sub 2/ or tmed) or (C/sub 5/Me/sub 5/)/sub 2/MCl(thf) (M = Nd or Yb). These compounds undergo metathesis reactions. The interaction of NaC/sub 5/Me/sub 5/ with EuCl/sub 3/ yields only the divalent (C/sub 5/Me/sub 5/)/sub 2/EuL (L = thf or OEt/sub 2/). Analogous compounds of ytterbium are obtained by reaction of YbI/sub 2/ with NaC/sub 5/Me/sub 5/ in thf or OEt/sub 2/. The ytterbium amine complexes are weakly paramagnetic, apparently due to charge transfer from ytterbium to the aromatic rings. The divalent phosphine complexes (C/sub 5/Me/sub 5/)/sub 2/ML (M = Eu or Yb; L = dmpe or dmpm) are also described. Crystallographic data are summarized.

  11. Multistage modeling of protein dynamics with monomeric Myc oncoprotein as an example

    Science.gov (United States)

    Liu, Jiaojiao; Dai, Jin; He, Jianfeng; Niemi, Antti J.; Ilieva, Nevena

    2017-03-01

    We propose to combine a mean-field approach with all-atom molecular dynamics (MD) into a multistage algorithm that can model protein folding and dynamics over very long time periods yet with atomic-level precision. As an example, we investigate an isolated monomeric Myc oncoprotein that has been implicated in carcinomas including those in colon, breast, and lungs. Under physiological conditions a monomeric Myc is presumed to be an example of intrinsically disordered proteins that pose a serious challenge to existing modeling techniques. We argue that a room-temperature monomeric Myc is in a dynamical state, it oscillates between different conformations that we identify. For this we adopt the C α backbone of Myc in a crystallographic heteromer as an initial ansatz for the monomeric structure. We construct a multisoliton of the pertinent Landau free energy to describe the C α profile with ultrahigh precision. We use Glauber dynamics to resolve how the multisoliton responds to repeated increases and decreases in ambient temperature. We confirm that the initial structure is unstable in isolation. We reveal a highly degenerate ground-state landscape, an attractive set towards which Glauber dynamics converges in the limit of vanishing ambient temperature. We analyze the thermal stability of this Glauber attractor using room-temperature molecular dynamics. We identify and scrutinize a particularly stable subset in which the two helical segments of the original multisoliton align in parallel next to each other. During the MD time evolution of a representative structure from this subset, we observe intermittent quasiparticle oscillations along the C-terminal α helix, some of which resemble a translating Davydov's Amide-I soliton. We propose that the presence of oscillatory motion is in line with the expected intrinsically disordered character of Myc.

  12. Fine blood vascular casting by monomeric methacrylate injection and microwave treatment

    OpenAIRE

    日根野谷, 仁

    1992-01-01

    A modified injection replica SEM method was introduced. Thorough injection of a resin mixture (monomeric metacrylate containing 1% benzoyl peroxide and 1% N, N-dimethylaniline) prior to the microwave treatment prepares good and fine blood vascular casts or replicas of brain, hypophysis, pineal body, thyroid gland and other organs. These casts sufficiently withstood ionbombardment and were useful for scanning electron microscopy. In this casting, preliminary perfusion fixation prior to the res...

  13. Heteroexpression and characterization of a monomeric isocitrate dehydrogenase from the multicellular prokaryote Streptomyces avermitilis MA-4680.

    Science.gov (United States)

    Wang, Ao; Cao, Zheng-Yu; Wang, Peng; Liu, Ai-Min; Pan, Wei; Wang, Jie; Zhu, Guo-Ping

    2011-08-01

    A monomeric NADP-dependent isocitrate dehydrogenase from the multicellular prokaryote Streptomyces avermitilis MA-4680 (SaIDH) was heteroexpressed in Escherichia coli, and the His-tagged enzyme was further purified to homogeneity. The molecular weight of SaIDH was about 80 kDa which is typical for monomeric isocitrate dehydrogenases. Structure-based sequence alignment reveals that the deduced amino acid sequence of SaIDH shows high sequence identity with known momomeric isocitrate dehydrogenase, and the coenzyme, substrate and metal ion binding sites are completely conserved. The optimal pH and temperature of SaIDH were found to be pH 9.4 and 45°C, respectively. Heat-inactivation studies showed that heating for 20 min at 50°C caused a 50% loss in enzymatic activity. In addition, SaIDH was absolutely specific for NADP+ as electron acceptor. Apparent Km values were 4.98 μM for NADP+ and 6,620 μM for NAD+, respectively, using Mn2+ as divalent cation. The enzyme performed a 33,000-fold greater specificity (kcat/Km) for NADP+ than NAD+. Moreover, SaIDH activity was entirely dependent on the presence of Mn2+ or Mg2+, but was strongly inhibited by Ca2+ and Zn2+. Taken together, our findings implicate the recombinant SaIDH is a divalent cation-dependent monomeric isocitrate dehydrogenase which presents a remarkably high cofactor preference for NADP+.

  14. Two mechanisms for dissipation of excess light in monomeric and trimeric light-harvesting complexes

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Osto, Luca [Univ. di Verona, Verona (Italy). Dipartimento di Biotecnologie; Cazzaniga, Stefano [Univ. di Verona, Verona (Italy). Dipartimento di Biotecnologie; Bressan, Mauro [Univ. di Verona, Verona (Italy). Dipartimento di Biotecnologie; Paleček, David [Lund Univ. (Sweden). Dept. of Chemical Physics; Židek, Karel [Lund Univ. (Sweden). Dept. of Chemical Physics; Niyogi, Krishna K. [Univ. of California, Berkeley, CA (United States). Howard Hughes Medical Inst., Dept. of Plant and Microbial Biology; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging Division; Fleming, Graham R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Biophysics and Integrated Bioimaging Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry, Graduate Group in Applied Science and Technology; Zigmantas, Donatas [Lund Univ. (Sweden). Dept. of Chemical Physics; Bassi, Roberto [Univ. di Verona, Verona (Italy). Dipartimento di Biotecnologie; Consiglio Nazionale delle Ricerche (CNR), Firenze (Italy). Istituto per la Protezione delle Piante (IPP)

    2017-04-10

    Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited states from light harvesting with the rate of electron transport from water to carbon dioxide. These photoprotective reactions prevent formation of reactive excited states and photoinhibition. The fastest response to excess illumination is the so-called non-photochemical quenching which, in higher plants, requires the luminal pH sensor PsbS and other yet unidentified components of the photosystem II antenna. Both trimeric light-harvesting complex II (LHCII) and monomeric LHC proteins have been indicated as site(s) of the heat-dissipative reactions. Different mechanisms have been proposed: Energy transfer to a lutein quencher in trimers, formation of a zeaxanthin radical cation in monomers. Here, we report on the construction of a mutant lacking all monomeric LHC proteins but retaining LHCII trimers. Its non-photochemical quenching induction rate was substantially slower with respect to the wild type. A carotenoid radical cation signal was detected in the wild type, although it was lost in the mutant. Here, we conclude that non-photochemical quenching is catalysed by two independent mechanisms, with the fastest activated response catalysed within monomeric LHC proteins depending on both zeaxanthin and lutein and on the formation of a radical cation. Trimeric LHCII was responsible for the slowly activated quenching component whereas inclusion in supercomplexes was not required. Finally, this latter activity does not depend on lutein nor on charge transfer events, whereas zeaxanthin was essential.

  15. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds.

    Science.gov (United States)

    Ma, Ruoshui; Guo, Mond; Lin, Kuan-Ting; Hebert, Vincent R; Zhang, Jinwen; Wolcott, Michael P; Quintero, Melissa; Ramasamy, Karthikeyan K; Chen, Xiaowen; Zhang, Xiao

    2016-07-25

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  16. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer as well as its complex side chain structures, it has been a challenge to effectively depolymerize lignin and produce high value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) inclduing 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPCs yields obtained were 18% and 22% based on the initial weight of the lignin in SESPL and DACSL respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47%. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  17. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  18. First synthesis and structural determination of a monomeric, unsolvated lithium amide, LiNH(2).

    Science.gov (United States)

    Grotjahn, D B; Sheridan, P M; Al Jihad, I; Ziurys, L M

    2001-06-13

    Alkali metal amides typically aggregate in solution and the solid phase, and even in the gas phase. In addition, even in the few known monomeric structures, the coordination number of the alkali metal is raised by binding of Lewis-basic solvent molecules, with concomitant changes in structure. In contrast, the simplest lithium amide LiNH(2) has never been made in a monomeric form, even though its structure has been theoretically predicted several times. Here, the first experimental structural data for a monomeric, unsolvated lithium amide are determined using a combination of gas-phase synthesis and millimeter/submillimeter-wave spectroscopy. All data point to a planar structure for LiNH(2). The r(o) structure of LiNH(2) has a Li-N distance of 1.736(3) A, an N-H distance of 1.022(3) A, and a H-N-H angle of 106.9(1) degrees. These results are compared with theoretical predictions for LiNH(2), and experimental data for oligomeric, solid-phase samples, which could not resolve the question of whether LiNH(2) is planar or not. In addition, comparisons are made with revised gas-phase and solid-phase data and calculated structures of NaNH(2).

  19. The peroxisomal protein import machinery displays a preference for monomeric substrates.

    Science.gov (United States)

    Freitas, Marta O; Francisco, Tânia; Rodrigues, Tony A; Lismont, Celien; Domingues, Pedro; Pinto, Manuel P; Grou, Cláudia P; Fransen, Marc; Azevedo, Jorge E

    2015-04-01

    Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and transported by the shuttling receptor PEX5 to the peroxisomal membrane docking/translocation machinery, where they are translocated into the organelle matrix. Under certain experimental conditions this protein import machinery has the remarkable capacity to accept already oligomerized proteins, a property that has heavily influenced current models on the mechanism of peroxisomal protein import. However, whether or not oligomeric proteins are really the best and most frequent clients of this machinery remain unclear. In this work, we present three lines of evidence suggesting that the peroxisomal import machinery displays a preference for monomeric proteins. First, in agreement with previous findings on catalase, we show that PEX5 binds newly synthesized (monomeric) acyl-CoA oxidase 1 (ACOX1) and urate oxidase (UOX), potently inhibiting their oligomerization. Second, in vitro import experiments suggest that monomeric ACOX1 and UOX are better peroxisomal import substrates than the corresponding oligomeric forms. Finally, we provide data strongly suggesting that although ACOX1 lacking a peroxisomal targeting signal can be imported into peroxisomes when co-expressed with ACOX1 containing its targeting signal, this import pathway is inefficient.

  20. Treatment of iron deficiency anemia: are monomeric iron compounds suitable for parenteral administration?

    Science.gov (United States)

    Gupta, A; Crumbliss, A L

    2000-11-01

    Iron deficiency is the most common nutritional problem worldwide, especially in the developing countries. Oral iron supplementation programs have failed because of noncompliance and gastrointestinal toxicity, thereby necessitating parenteral administration of iron. For parenteral administration, only iron-carbohydrate complexes are currently used, because monomeric iron salts release free iron, thereby causing oxidant injury. However, iron-carbohydrate complexes also have significant toxicity, and they are expensive. We have proposed the hypothesis that monomeric iron salts can be safely administered by the parenteral route if iron is tightly complexed to the ligand, thereby causing clinically insignificant release of free iron, and the kinetic properties of the compound allow rapid transfer of iron to plasma transferrin. A detailed analysis of the physicochemical and kinetic properties reveals that ferric iron complexed to pyrophosphate or acetohydroxamate anions may be suitable for parenteral administration. We have demonstrated that infusion of ferric pyrophosphate into the circulation via the dialysate is safe and effective in maintaining iron balance in patients undergoing maintenance hemodialysis. Parenteral administration of monomeric iron compounds is a promising approach to the treatment of iron deficiency in the general population and merits further investigation.

  1. Binding of the monomeric form of C-reactive protein to enzymatically-modified low-density lipoprotein: effects of phosphoethanolamine

    Science.gov (United States)

    Singh, Sanjay K.; Suresh, Madathilparambil V.; Hammond, David J.; Rusiñol, Antonio E.; Potempa, Lawrence A.; Agrawal, Alok

    2009-01-01

    Background The 5 subunits of native pentameric C-reactive protein (CRP) are dissociated to generate monomeric form of CRP (mCRP) in some in vitro conditions, both physiological and non-physiological, and also in vivo. Many bioactivities of mCRP generated by urea-treatment of CRP and of mCRP generated by mutating the primary structure of CRP have been reported. The bioactivities of mCRP generated by spontaneous dissociation of CRP are largely unexplored. Methods We purified mCRP generated by spontaneous dissociation of CRP and investigated the binding of mCRP to enzymatically-modified low-density lipoprotein (E-LDL). Results mCRP was approximately 60 times more potent than CRP in binding to E-LDL. In the presence of the small-molecule compound phosphoethanolamine (PEt), at 37°C, the binding of mCRP to E-LDL was enhanced 10-fold. In contrast, PEt inhibited the binding of both CRP and mCRP to pneumococcal C-polysaccharide, another phosphocholine-containing ligand to which CRP and mCRP were found to bind. We have not investigated yet whether PEt alters the structure of CRP at 37°C. Conclusions Combined data suggest that the targeting of CRP with the aim to monomerize CRP in vivo may be an effective approach to capture modified forms of LDL. PMID:19545552

  2. Avaliação da viscosidade durante a fabricação do doce de leite tradicional adicionado de amido de milho nativo.

    Directory of Open Access Journals (Sweden)

    Monique Colombo

    2009-10-01

    Full Text Available O doce de leite é o principal produto concentrado produzido no Brasil. Minas Gerais responde por 50% da produção brasileira de doce de leite tendo, por este motivo, o maior parque industrial. O objetivo deste trabalho foi estudar a variação da viscosidade durante a fabricação do doce de leite tradicional adicionado de amido de milho nativo. Os resultados encontrados mostram a elevação da viscosidade do doce durante a fabricação e um aumento pronunciado após 60 minutos de fervura, o que, baseado nas imagens microscópicas, pode ser atribuído à exposição da amilose por rompimento da estrutura do amido nativo.

  3. Insights into amine binding to biaryl phosphine palladium oxidative addition complexes and reductive elimination from biaryl phosphine arylpalladium amido complexes via density functional theory.

    Science.gov (United States)

    Barder, Timothy E; Buchwald, Stephen L

    2007-10-03

    We present results on the binding of a variety amines to monoligated oxidative addition complexes of the type L1Pd(Ar)Cl, where L is 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos, 1) or 2-dicyclohexylphosphino-2',4',6'-tri-ispropylbiphenyl (XPhos, 2). The binding of an amine to oxidative addition complexes composed of 1 and 2 is more complex than with smaller ligands as intermediate Pd(II) complexes with bulky biaryl phosphine ligands disfavor amine binding to favorable conformations of oxidative addition complexes. Additionally, thermodynamic and kinetic parameters for reductive elimination from complexes of the type L1Pd(amido)Ph (where amido = EtNH, Me2N, PhNH) are discussed. From this data, we suggest a possible mechanism for (biaryl phosphine) Pd-catalyzed amination reactions that is more intricate than previously thought.

  4. Synthesis, structure, and reactivity of tris(amidate) mono(amido) and tetrakis(amidate) complexes of group 4 transition metals.

    Science.gov (United States)

    Payne, Philippa R; Thomson, Robert K; Medeiros, Diane M; Wan, Geoff; Schafer, Laurel L

    2013-11-28

    The syntheses of a series of tris(amidate) mono(amido) titanium and zirconium complexes are reported. The binding motif of the amidate ligand has been determined to depend on the size of the metal centre for these sterically demanding N,O-chelating ligands; the larger zirconium metal centre supports three κ(2)-(N,O) bound amidate ligands while the titanium analogue has one ligand bound in a κ(1)-(O) fashion to alleviate steric strain. Reactivity studies indicate that, despite high steric crowding about the tris(amidate) mono(amido) zirconium metal centre, transamination of the reactive dimethylamido ligand can be achieved using aniline. This complex is also an active precatalyst for intramolecular alkene hydroamination, in which protonolysis of one amidate ligand in the presence of excess amine is observed as an initiation step prior to catalytic turnover. Eight-coordinate homoleptic κ(2)-amidate complexes of zirconium and hafnium have also been prepared.

  5. Synthesis of quaternary derivatives of ortho-coco di-amido toluene and investigation of these compounds as cationic bitumen emulsifier

    Energy Technology Data Exchange (ETDEWEB)

    Hassanzadeh, Masoumeh; Tayebi, Leila; Dezfouli, Hedieh; Kambarani, Masoud; Avval, Parviz Ahmadi [Tehran Univ. (Iran, Islamic Republic of). ACECR, Designing Chemical Process Research Group

    2012-05-15

    Bitumen emulsions are preferred over conventional pavement systems due to their biologically and environmentally acceptable formulation, safety, low viscosity, storage stability, and cost effectiveness. The present investigation deals with the systematic study to synthesize ortho-cocodi-amido toluene and four quaternary derivatives by amidation of coconut oil and ortho toluene diamine (OTD), followed by quaternization with formaldehyde, formic acid mixture, and acrylonitrile, resulted in a new quaternary compound useful as cationic emulsifier in bitumen emulsions. The roles of temperature and reaction time in determining optimum conditions were investigated as well. Emulsifying behavior of these quaternary compounds was studied by sieve residue test, settlement and storage stability test of emulsified asphalt, and water solubility. The results show that the acrylonitrile imidazolinium derivative of o-cocodi-amido toluene (VI) can be used as a rapid-medium setting emulsifier. (orig.)

  6. Adsorption of Amido Black 10B from aqueous solutions onto Zr (IV) surface-immobilized cross-linked chitosan/bentonite composite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lujie; Hu, Pan; Wang, Jing; Huang, Ruihua, E-mail: hrh20022002@163.com

    2016-04-30

    Graphical abstract: - Highlights: • Zr-CCB was prepared and characterized. • The adsorption of AB10B followed the Langmuir isotherm model. • The pseudo-second-order model described the kinetic behavior. - Abstract: Zr(IV) surface-immobilized cross-linked chitosan/bentonite composite was synthesized by immersing cross-linked chitosan/bentonite composite in zirconium oxychloride solution, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy techniques. The adsorption of an anionic dye, Amido Black 10B, from aqueous solution by Zr(IV) loaded cross-linked chitosan/bentonite composite was investigated as a function of loading amount of Zr(IV), adsorbent dosage, pH value of initial dye solution, and ionic strength. The removal of Amido Black 10B increased with an increase in loading amount of Zr(IV) and adsorbent dosage, but decreased with an increase in pH or ionic strength. The adsorption of AB10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite was favored at lower pH values and higher temperatures. The Langmuir isotherm model fitted well with the equilibrium adsorption isotherm data and the maximum monolayer adsorption capacity was 418.4 mg/g at natural pH value and 298 K. The pseudo-second-order kinetic model well described the adsorption process of Amido Black 10B onto Zr(IV) loaded cross-linked chitosan/bentonite composite. The possible mechanisms controlling Amido Black 10B adsorption included hydrogen bonding and electrostatic interactions.

  7. A novel tool for studying auxin-metabolism: the inhibition of grapevine indole-3-acetic acid-amido synthetases by a reaction intermediate analogue.

    Directory of Open Access Journals (Sweden)

    Christine Böttcher

    Full Text Available An important process for the regulation of auxin levels in plants is the inactivation of indole-3-acetic acid (IAA by conjugation to amino acids. The conjugation reaction is catalysed by IAA-amido synthetases belonging to the family of GH3 proteins. Genetic approaches to study the biological significance of these enzymes have been hampered by large gene numbers and a high degree of functional redundancy. To overcome these difficulties a chemical approach based on the reaction mechanism of GH3 proteins was employed to design a small molecule inhibitor of IAA-amido synthetase activity. Adenosine-5'-[2-(1H-indol-3-ylethyl]phosphate (AIEP mimics the adenylated intermediate of the IAA-conjugation reaction and was therefore proposed to compete with the binding of MgATP and IAA in the initial stages of catalysis. Two grapevine IAA-amido synthetases with different catalytic properties were chosen to test the inhibitory effects of AIEP in vitro. GH3-1 has previously been implicated in the grape berry ripening process and is restricted to two amino acid substrates, whereas GH3-6 conjugated IAA to 13 amino acids. AIEP is the most potent inhibitor of GH3 enzymes so far described and was shown to be competitive against MgATP and IAA binding to both enzymes with K(i-values 17-68-fold lower than the respective K(m-values. AIEP also exhibited in vivo activity in an ex planta test system using young grape berries. Exposure to 5-20 µM of the inhibitor led to decreased levels of the common conjugate IAA-Asp and reduced the accumulation of the corresponding Asp-conjugate upon treatment with a synthetic auxin. AIEP therefore represents a novel chemical probe with which to study IAA-amido synthetase function.

  8. Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyloxazoles

    Directory of Open Access Journals (Sweden)

    Kandasamy Rajaguru

    2015-10-01

    Full Text Available The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates. An interesting reaction is described wherein, with trifluoroacetic acid at lower temperature, it affords highly substituted 2-(trifluoromethyloxazoles. These flexible transformations proceed under solvent free conditions in good to excellent yields without any catalyst.

  9. Synthesis and Cytotoxicity Testing of New Amido-Substituted Triazolopyrrolo[2,1-c][1,4]benzodiazepine (PBDT Derivatives

    Directory of Open Access Journals (Sweden)

    Bo-Ying Bao

    2012-07-01

    Full Text Available A series of amido-substituted triazolopyrrolo[2,1-c][1,4]benzodiazepine (PBDT derivatives was synthesized from isatoic anhydride, and their cytotoxicity against the MRC-5 and Mahlavu cell lines was evaluated. The results suggest that compound PBDT-7i with the meta-trifluoromethylbenzoyl substituent can selectively inhibit the growth of Mahlavu cells and has low toxicity towards MRC-5 cells.

  10. How do the full-generation poly(amido)amine (PAMAM) dendrimers activate blood platelets? Activation of circulating platelets and formation of "fibrinogen aggregates" in the presence of polycations.

    Science.gov (United States)

    Watala, Cezary; Karolczak, Kamil; Kassassir, Hassan; Talar, Marcin; Przygodzki, Tomasz; Maczynska, Katarzyna; Labieniec-Watala, Magdalena

    2016-04-30

    Direct use of poly(amido)amine (PAMAM) dendrimers as drugs may be limited, due to uncertain (cyto)toxicity. Peripheral blood components, which constitute the first line of a contact with administered pharmaceuticals, may become vastly affected by PAMAM dendrimers. The aim of this study was to explore how PAMAMs' polycationicity might affect blood platelet activation and reactivity, and thus trigger various haemostatic events. We monitored blood platelet reactivity in rats with experimental diabetes upon a long-term administration of the unmodified PAMAM dendrimers. In parallel, the effects on blood flow in a systemic circulation was recorded intravitally in mice administered with PAMAM G2, G3 or G4. Compounding was the in vitro approach to monitor the impact of PAMAM dendrimers on blood platelet activation and reactivity and on selected haemostatic and protein conformation parameters. We demonstrated the activating effects of polycations on blood platelets. Some diversity of the revealed outcomes considerably depended on the used approach and the particular technique employed to monitor blood platelet function. We discovered undesirable impact of plain PAMAM dendrimers on primary haemostasis and their prothrombotic influence. We emphasize the need of a more profound verifying of all the promising findings collected for PAMAMs with the use of well-designed in vivo preclinical studies.

  11. Resposta plasmática de glicose e insulina em eqüinos alimentados com diferentes fontes de amido

    Directory of Open Access Journals (Sweden)

    Alexandre Augusto de Oliveira Gobesso

    2009-08-01

    Full Text Available O objetivo deste trabalho foi medir a resposta plasmática de glicose e insulina em cavalos alimentados com dietas contendo concentrados energéticos formulados com diferentes fontes de amido, tais como milho, aveia, sorgo e uma mistura de milho e aveia em partes iguais por peso. Foram utilizados quatro eqüinos com 36 meses de idade em media, mestiços, machos, castrados, com peso aproximado de 350 kg. O delineamento experimental utilizado foi um quadrado latino 4X4 (quatro animais, quatro tratamentos, quatro períodos. Os resultados foram processados através de programa computacional, a normalidade dos resíduos verificada pelo Teste de Shapiro - Wilk, e as variâncias comparadas pelo teste F. Não foram observadas diferenças nos níveis de glicose plasmática entre tratamentos. No caso da glicose, todos os tratamentos atingiram seu máximo nível duas horas e meia pós-ingestão O nível de insulina plasmática foi significativamente inferior antes da refeição em aqueles cavalos tratados com a mistura de milho e aveia, e significativamente superior nos cavalos alimentados com milho como fonte de energia três horas e meia pós ingesta. Os valores de glicose e insulina plasmática observados neste estudo podem ter sido influenciados pelo processamento das dietas na forma peletizada, promovendo uma maior absorção de glicose no intestino delgado. As dietas contendo diferentes fontes de amido não influenciaram nem o tempo nem a quantidade de glicose absorvida no intestino delgado. As variações observadas nos níveis de insulina indicam que um manejo alimentar apropriado pode influenciar os níveis deste hormônio, moderando os seus efeitos indesejáveis.

  12. Monomeric banana lectin at acidic pH overrules conformational stability of its native dimeric form.

    Directory of Open Access Journals (Sweden)

    Javed M Khan

    Full Text Available Banana lectin (BL is a homodimeric protein categorized among jacalin-related family of lectins. The effect of acidic pH was examined on conformational stability of BL by using circular dichroism, intrinsic fluorescence, 1-anilino-8-napthalene sulfonate (ANS binding, size exclusion chromatography (SEC and dynamic light scattering (DLS. During acid denaturation of BL, the monomerization of native dimeric protein was found at pH 2.0. The elution profile from SEC showed two different peaks (59.65 ml & 87.98 ml at pH 2.0 while single peak (61.45 ml at pH 7.4. The hydrodynamic radii (R h of native BL was 2.9 nm while at pH 2.0 two species were found with R h of 1.7 and 3.7 nm. Furthermore at, pH 2.0 the secondary structures of BL remained unaltered while tertiary structure was significantly disrupted with the exposure of hydrophobic clusters confirming the existence of molten globule like state. The unfolding of BL with different subunit status was further evaluated by urea and temperature mediated denaturation to check their stability. As inferred from high Cm and ΔG values, the monomeric form of BL offers more resistance towards chemical denaturation than the native dimeric form. Besides, dimeric BL exhibited a Tm of 77°C while no loss in secondary structures was observed in monomers even up to 95°C. To the best of our knowledge, this is the first report on monomeric subunit of lectins showing more stability against denaturants than its native dimeric state.

  13. Conformational equilibria in monomeric alpha-synuclein at the single-molecule level.

    Directory of Open Access Journals (Sweden)

    Massimo Sandal

    2008-01-01

    Full Text Available Human alpha-Synuclein (alphaSyn is a natively unfolded protein whose aggregation into amyloid fibrils is involved in the pathology of Parkinson disease. A full comprehension of the structure and dynamics of early intermediates leading to the aggregated states is an unsolved problem of essential importance to researchers attempting to decipher the molecular mechanisms of alphaSyn aggregation and formation of fibrils. Traditional bulk techniques used so far to solve this problem point to a direct correlation between alphaSyn's unique conformational properties and its propensity to aggregate, but these techniques can only provide ensemble-averaged information for monomers and oligomers alike. They therefore cannot characterize the full complexity of the conformational equilibria that trigger the aggregation process. We applied atomic force microscopy-based single-molecule mechanical unfolding methodology to study the conformational equilibrium of human wild-type and mutant alphaSyn. The conformational heterogeneity of monomeric alphaSyn was characterized at the single-molecule level. Three main classes of conformations, including disordered and "beta-like" structures, were directly observed and quantified without any interference from oligomeric soluble forms. The relative abundance of the "beta-like" structures significantly increased in different conditions promoting the aggregation of alphaSyn: the presence of Cu2+, the pathogenic A30P mutation, and high ionic strength. This methodology can explore the full conformational space of a protein at the single-molecule level, detecting even poorly populated conformers and measuring their distribution in a variety of biologically important conditions. To the best of our knowledge, we present for the first time evidence of a conformational equilibrium that controls the population of a specific class of monomeric alphaSyn conformers, positively correlated with conditions known to promote the formation of

  14. Isolation of monomeric photosystem II that retains the subunit PsbS.

    Science.gov (United States)

    Haniewicz, Patrycja; De Sanctis, Daniele; Büchel, Claudia; Schröder, Wolfgang P; Loi, Maria Cecilia; Kieselbach, Thomas; Bochtler, Matthias; Piano, Dario

    2013-12-01

    Photosystem II has been purified from a transplastomic strain of Nicotiana tabacum according to two different protocols. Using the procedure described in Piano et al. (Photosynth Res 106:221-226, 2010) it was possible to isolate highly active PSII composed of monomers and dimers but depleted in their PsbS protein content. A "milder" procedure than the protocol reported by Fey et al. (Biochim Biophys Acta 1777:1501-1509, 2008) led to almost exclusively monomeric PSII complexes which in part still bind the PsbS protein. This finding might support a role for PSII monomers in higher plants.

  15. Monomeric CH3: A Small, Stable Antibody Domain with Therapeutic Promise | Poster

    Science.gov (United States)

    By Ashley DeVine, Staff Writer Antibody domains are emerging as promising biopharmaceuticals because of their relatively small size compared to full-sized antibodies, which are too large to effectively penetrate tumors and bind to sterically restricted therapeutic targets. In an article published in The Journal of Biological Chemistry, Tianlei Ying, Ph.D., Dimiter Dimitrov, Ph.D., and their colleagues in the Protein Interactions Group, Cancer and Inflammation Program, Center for Cancer Research, reported their design of a novel antibody domain, monomeric CH3 (mCH3).

  16. The Beckman DxI 800 prolactin assay demonstrates superior specificity for monomeric prolactin.

    LENUS (Irish Health Repository)

    Byrne, Brendan

    2010-02-01

    Commercially available prolactin immunoassays detect macroprolactin to variable degrees. Best practice requires laboratories to assess the cross-reactivity of their prolactin assay with macroprolactin, and where appropriate, introduce a screen for the presence of macroprolactin. Our policy has been to reanalyse hyperprolactinaemic samples following polyethylene glycol (PEG) precipitation and to report the resultant value as the monomeric prolactin content of the sample. The goal of this study was to determine the need to continue PEG precipitation when prolactin measurements with the Wallac AutoDELFIA were replaced by the Beckman DxI 800.

  17. Effect of biodegradable starch packing on storage of processed cheese/ Efeito de embalagem biodegradável de amido no armazenamento de queijo processado

    Directory of Open Access Journals (Sweden)

    Maria Victória Eiras Grossmann

    2006-06-01

    Full Text Available There is an increasing interest in the utilization of renewable resources for the production of food packaging. Among the biopolymers, starches from several sources have been considered as one of the most promising material for this purpose; and the reasons for this are that starches are biodegradable, inexpensive and available in all world. This work had the objective of evaluate the effect of yam starch biodegradable packaging on storage (30 days / 4oC of comercial-processed cheese and to compare with conventional packaging. The results showed that conventional packaging presented the better behavior on weight and water activity retention of samples during all storage time than starch packaging. Considering microbiological counts, only control samples (unpackaged showed contamination. Titratable acidity and pH of packaged samples did not differ for starch or conventional package (Tukey test, p ? 0.05 during all storage time. Considering the presented results, yam starch could be used as an alternative to package processed cheese, but more studies have to be done to improve starch films as a water vapor barrier.Há um interesse crescente no emprego de matérias-primas provenientes de recursos renováveis para a produção de embalagens para alimentos. Dentre os biopolímeros mais promissores para este fim estão os amidos de diversas fontes botânicas, que são biodegradáveis, têm custo baixo e estão disponíveis em todo o mundo. Assim sendo, este trabalho teve como objetivo avaliar o efeito de embalagens biodegradáveis de amido de inhame no armazenamento (30 dias / 4oc de queijo processado obtido de fonte comercial, e comparar o seu desempenho com o de embalagens convencionais. Os resultados obtidos mostraram que a embalagem convencional foi mais eficaz na retenção do peso e atividade de água das amostras do que a embalagem de amido. Quanto à contagem microbiana, apenas as amostras não embaladas apresentaram contaminação. A acidez

  18. DNA Condensation by Partially Acetylated Poly(amido amine Dendrimers: Effects of Dendrimer Charge Density on Complex Formation

    Directory of Open Access Journals (Sweden)

    Ronald G. Larson

    2013-09-01

    Full Text Available The ability of poly(amido amine (or PAMAM dendrimers to condense semiflexible dsDNA and penetrate cell membranes gives them great potential in gene therapy and drug delivery but their high positive surface charge makes them cytotoxic. Here, we describe the effects of partial neutralization by acetylation on DNA condensation using light scattering, circular dichroism, and single molecule imaging of dendrimer-DNA complexes combed onto surfaces and tethered to those surfaces under flow. We find that DNA can be condensed by generation-five (G5 dendrimers even when the surface charges are more than 65% neutralized, but that such dendrimers bind negligibly when an end-tethered DNA is stretched in flow. We also find that when fully charged dendrimers are introduced by flow to end-tethered DNA, all DNA molecules become equally highly coated with dendrimers at a rate that becomes very fast at high dendrimer concentration, and that dendrimers remain bound during subsequent flow of dendrimer-free buffer. These results suggest that the presence of dendrimer-free DNA coexisting with dendrimer-bound DNA after bulk mixing of the two in solution may result from diffusion-limited irreversible dendrimer-DNA binding, rather than, or in addition to, the previously proposed cooperative binding mechanism of dendrimers to DNA.

  19. Combined Molecular Dynamics Simulations and Experimental Studies of the Structure and Dynamics of Poly-Amido-Saccharides.

    Science.gov (United States)

    Chin, Stacy L; Lu, Qing; Dane, Eric L; Dominguez, Laura; McKnight, Christopher J; Straub, John E; Grinstaff, Mark W

    2016-05-25

    Poly-amido-saccharides (PAS) are carbohydrate-based, enantiopure synthetic polymers in which sugar repeat units are joined by amide linkages. This unique and relatively rigid pyranose backbone contributes to their defined helical secondary structure and remarkable chemical properties. Glucose- (glc-) and galactose- (gal-) PAS 10-mer structures are synthesized and investigated with molecular dynamics (MD) simulations and experimental measurements. Quantum mechanical DFT energy minimization calculations, as well as experimental observables including circular dichroism, (1)H,(13)C-HSQC, and (1)H,(1)H-NOESY 2D-NMR studies, validated the all-atom simulation models produced using a modified CHARMM force field. Water radial distribution functions show distinct differences in the glc- and gal-PAS systems that correlate well with observed differences in solubility between gal-PASs and glc-PASs. The computational analysis and MD simulations are in good agreement with experimental results, validating the proposed models as reliable representations of novel glc- and gal-PASs.

  20. Ruthenium complexes of chelating amido-functionalized N-heterocyclic carbene ligands: Synthesis, structure and DFT studies

    Indian Academy of Sciences (India)

    Sachin Kumar; Anantha Narayanan; Mitta Nageswar Rao; Mobin M Shaikh; Prasenjit Ghosh

    2011-11-01

    Synthesis, structure and density functional theory (DFT) studies of a series of new ruthenium complexes, [1-(R)-3--(benzylacetamido)imidazol-2-ylidene]RuCl(-cymene) [R = Me (1c), -Pr (2c), CH2Ph (3c); -cymene = 4--propyltoluene] supported over /-functionalized N-heterocyclic carbene (NHC) ligands are reported. In particular, the ruthenium (1-3)c complexes were synthesized from the respective silver complexes, [1-(R)-3--(benzylacetamido)imidazol-2-ylidene]2Ag+Cl− [R = Me (1b), -Pr (2b), CH2Ph (3b)] by the treatment with [Ru(-cymene)Cl2]2 in 65-76% yields. The molecular structures of (1-3)c revealed the chelation of the N-heterocylic carbene ligand through the carbene center and an amido sidearm of the ligand in all of the three complexes. The density functional theory studies on the ruthenium (1-3)c complexes indicated strong binding of the NHC ligand to the metal center as was observed from the deeply buried NHC-Ru -bonding molecular orbitals.

  1. Mechanistic Studies of Hafnium-Pyridyl Amido-Catalyzed 1-Octene Polymerization and Chain Transfer Using Quench-Labeling Methods.

    Science.gov (United States)

    Cueny, Eric S; Johnson, Heather C; Anding, Bernie J; Landis, Clark R

    2017-08-30

    Chromophore quench-labeling applied to 1-octene polymerization as catalyzed by hafnium-pyridyl amido precursors enables quantification of the amount of active catalyst and observation of the molecular weight distribution (MWD) of Hf-bound polymers via UV-GPC analysis. Comparison of the UV-detected MWD with the MWD of the "bulk" (all polymers, from RI-GPC analysis) provides important mechanistic information. The time evolution of the dual-detection GPC data, concentration of active catalyst, and monomer consumption suggests optimal activation conditions for the Hf pre-catalyst in the presence of the activator [Ph3C][B(C6F5)4]. The chromophore quench-labeling agents do not react with the chain-transfer agent ZnEt2 under the reaction conditions. Thus, Hf-bound polymeryls are selectively labeled in the presence of zinc-polymeryls. Quench-labeling studies in the presence of ZnEt2 reveal that ZnEt2 does not influence the rate of propagation at the Hf center, and chain transfer of Hf-bound polymers to ZnEt2 is fast and quasi-irreversible. The quench-label techniques represent a means to study commercial polymerization catalysts that operate with high efficiency at low catalyst concentrations without the need for specialized equipment.

  2. Piano-Stool Lutetium Amido and Imido Compounds Supported by a Constrained Bis(oxazoline)cyclopentadienyl Ligand.

    Science.gov (United States)

    Lampland, Nicole L; Zhu, Jing; Hovey, Megan; Jana, Barun; Ellern, Arkady; Sadow, Aaron D

    2015-07-20

    {Bo(M)Cp(tet)}Lu(CH2Ph)2 (1; Bo(M)Cp(tet) = MeC(Ox(Me2))2C5Me4; Ox(Me2) = 4,4-dimethyl-2-oxazoline) was prepared in 95% yield from the reaction of Bo(M)Cp(tet)H and Lu(CH2Ph)3THF3. Compound 1 reacts with 1 or 2 equiv of H2NCH2R (R = C6H5, 1-C10H7) to give the corresponding imido complexes [{Bo(M)Cp(tet)}LuNCH2R]2 (R = C6H5 (2a), 1-C10H7 (2b)) or amido complexes {Bo(M)Cp(tet)}Lu(NHCH2R)2 (R = C6H5 (3a), 1-C10H7 (3b)). Once isolated, the imido species are insoluble in nonprotic organic solvents. Crystallographic characterization reveals dimeric [{Bo(M)Cp(tet)}LuNCH2(1-C10H7)]2 in the solid state. The reaction of 1 and NH3B(C6F5)3 affords crystallographically characterized {Bo(M)Cp(tet)}Lu{NHB(C6F5)2}C6F5. This species is proposed to form via a transient lutetium imido, which undergoes C6F5 migration to the lutetium center.

  3. Combinatorial Synthesis, Screening, and Binding Studies of Highly Functionalized Polyamino-amido Oligomers for Binding to Folded RNA

    Directory of Open Access Journals (Sweden)

    Jonathan K. Pokorski

    2012-01-01

    Full Text Available Folded RNA molecules have recently emerged as critical regulatory elements in biological pathways, serving not just as carriers of genetic information but also as key components in enzymatic assemblies. In particular, the transactivation response element (TAR of the HIV genome regulates transcriptional elongation by interacting specifically with the Tat protein, initiating the recruitment of the elongation complex. Preventing this interaction from occurring in vivo halts HIV replication, thus making RNA-binding molecules an intriguing pharmaceutical target. Using α-amino acids as starting materials, we have designed and synthesized a new class of polyamino-amido oligomers, called PAAs, specifically for binding to folded RNA structures. The PAA monomers were readily incorporated into a 125-member combinatorial library of PAA trimers. In order to rapidly assess RNA binding, a quantum dot-based fluorescent screen was developed to visualize RNA binding on-resin. The binding affinities of hits were quantified using a terbium footprinting assay, allowing us to identify a ligand (SFF with low micromolar affinity (kd=14 μM for TAR RNA. The work presented herein represents the development of a flexible scaffold that can be easily synthesized, screened, and subsequently modified to provide ligands specific for binding to folded RNAs.

  4. Allosteric Partial Inhibition of Monomeric Proteases. Sulfated Coumarins Induce Regulation, not just Inhibition, of Thrombin

    Science.gov (United States)

    Verespy III, Stephen; Mehta, Akul Y.; Afosah, Daniel; Al-Horani, Rami A.; Desai, Umesh R.

    2016-01-01

    Allosteric partial inhibition of soluble, monomeric proteases can offer major regulatory advantages, but remains a concept on paper to date; although it has been routinely documented for receptors and oligomeric proteins. Thrombin, a key protease of the coagulation cascade, displays significant conformational plasticity, which presents an attractive opportunity to discover small molecule probes that induce sub-maximal allosteric inhibition. We synthesized a focused library of some 36 sulfated coumarins to discover two agents that display sub-maximal efficacy (~50%), high potency (150-fold). Michaelis-Menten, competitive inhibition, and site-directed mutagenesis studies identified exosite 2 as the site of binding for the most potent sulfated coumarin. Stern-Volmer quenching of active site-labeled fluorophore suggested that the allosteric regulators induce intermediate structural changes in the active site as compared to those that display ~80–100% efficacy. Antithrombin inactivation of thrombin was impaired in the presence of the sulfated coumarins suggesting that allosteric partial inhibition arises from catalytic dysfunction of the active site. Overall, sulfated coumarins represent first-in-class, sub-maximal inhibitors of thrombin. The probes establish the concept of allosteric partial inhibition of soluble, monomeric proteins. This concept may lead to a new class of anticoagulants that are completely devoid of bleeding. PMID:27053426

  5. Nortriptyline inhibits aggregation and neurotoxicity of alpha-synuclein by enhancing reconfiguration of the monomeric form.

    Science.gov (United States)

    Collier, Timothy J; Srivastava, Kinshuk R; Justman, Craig; Grammatopoulous, Tom; Hutter-Paier, Birgit; Prokesch, Manuela; Havas, Daniel; Rochet, Jean-Christophe; Liu, Fang; Jock, Kevin; de Oliveira, Patrícia; Stirtz, Georgia L; Dettmer, Ulf; Sortwell, Caryl E; Feany, Mel B; Lansbury, Peter; Lapidus, Lisa; Paumier, Katrina L

    2017-10-01

    The pathology of Parkinson's disease and other synucleinopathies is characterized by the formation of intracellular inclusions comprised primarily of misfolded, fibrillar α-synuclein (α-syn). One strategy to slow disease progression is to prevent the misfolding and aggregation of its native monomeric form. Here we present findings that support the contention that the tricyclic antidepressant compound nortriptyline (NOR) has disease-modifying potential for synucleinopathies. Findings from in vitro aggregation and kinetics assays support the view that NOR inhibits aggregation of α-syn by directly binding to the soluble, monomeric form, and by enhancing reconfiguration of the monomer, inhibits formation of toxic conformations of the protein. We go on to demonstrate that NOR inhibits the accumulation, aggregation and neurotoxicity of α-syn in multiple cell and animal models. These findings suggest that NOR, a compound with established safety and efficacy for treatment of depression, may slow progression of α-syn pathology by directly binding to soluble, native, α-syn, thereby inhibiting pathological aggregation and preserving its normal functions. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Monomeric, Oligomeric and Polymeric Proteins in Huntington Disease and Other Diseases of Polyglutamine Expansion

    Directory of Open Access Journals (Sweden)

    Guylaine Hoffner

    2014-03-01

    Full Text Available Huntington disease and other diseases of polyglutamine expansion are each caused by a different protein bearing an excessively long polyglutamine sequence and are associated with neuronal death. Although these diseases affect largely different brain regions, they all share a number of characteristics, and, therefore, are likely to possess a common mechanism. In all of the diseases, the causative protein is proteolyzed, becomes abnormally folded and accumulates in oligomers and larger aggregates. The aggregated and possibly the monomeric expanded polyglutamine are likely to play a critical role in the pathogenesis and there is increasing evidence that the secondary structure of the protein influences its toxicity. We describe here, with special attention to huntingtin, the mechanisms of polyglutamine aggregation and the modulation of aggregation by the sequences flanking the polyglutamine. We give a comprehensive picture of the characteristics of monomeric and aggregated polyglutamine, including morphology, composition, seeding ability, secondary structure, and toxicity. The structural heterogeneity of aggregated polyglutamine may explain why polyglutamine-containing aggregates could paradoxically be either toxic or neuroprotective.

  7. Synthesis and characterization of a monomeric mutant Cu/Zn superoxide dismutase with partially reconstituted enzymic activity.

    Science.gov (United States)

    Banci, L; Bertini, I; Chiu, C Y; Mullenbach, G T; Viezzoli, M S

    1995-12-15

    A monomeric analog of human Cu/Zn superoxide dismutase (F50E/G51E SOD), previously characterized and found to have reduced enzymic activity, was here further modified by replacing Glu133 with Gln. This substitution does not dramatically affect the coordination geometry at the active site, but enhances enzymic activity, and also increases the affinity for anions at the active site. This behavior parallels earlier published results in which this point mutation was made in the dimeric wild-type enzyme. The analog described here has afforded for the first time a monomeric superoxide dismutase with substantial activity. This point mutation does not significantly influence the protein structure but interactions with anions, including superoxide, are altered with respect to the monomeric form. The present monomeric Glu133Gln mutant has partially restored enzymic activity. The diminished activity of the monomeric analogs is discussed in the light of possible minor structural changes and some of their characteristics are compared with those of naturally occurring mutants associated with various neurological diseases.

  8. Properties and metathesis activity of monomeric and dimeric Mo centres variously located on γ-alumina A DFT study

    Science.gov (United States)

    Handzlik, Jarosław

    2007-05-01

    Ethene metathesis proceeding on monomeric and dimeric Mo species on the (1 0 0) and (1 1 0) γ-alumina is investigated by density functional theory, applying the cluster approach. The calculated vibrational frequencies of the surface OH groups are assigned to the experimental IR bands. It is shown that both monomeric and dimeric Mo forms can be the active sites of olefin metathesis. Metathesis activity and stability of the Mo-methylidene centres depend on their location on alumina. The differences in the sites reactivity are explained on the basis of their geometrical and electronic structure parameters. For the monomeric centres, isomerisation of the trigonal bipyramidal intermediate to the stable square pyramidal molybdacyclobutane is kinetically favoured over the cycloreversal step. The situation is opposite in the case of the dimeric species.

  9. Lyophilization-induced protein denaturation in phosphate buffer systems: monomeric and tetrameric beta-galactosidase.

    Science.gov (United States)

    Pikal-Cleland, K A; Carpenter, J F

    2001-09-01

    During freezing in phosphate buffers, selective precipitation of a less soluble buffer component and subsequent pH shifts may induce protein denaturation. Previous reports indicate significantly more inactivation and secondary structural perturbation of monomeric and tetrameric beta-galactosidase (beta-gal) during freeze-thawing in sodium phosphate (NaP) buffer as compared with potassium phosphate (KP) buffer. This observation was attributed to the significant pH shifts (from 7.0 to as low as 3.8) observed during freezing in the NaP buffer (1). In the current study, we investigated the impact of the additional stress of dehydration after freezing on the recovery of active protein on reconstitution and the retention of the native structure in the dried state. Freeze-drying monomeric and tetrameric beta-gal in either NaP or KP buffer resulted in significant secondary structural perturbations, which were greatest for the NaP samples. However, similar recoveries of active monomeric protein were observed after freeze-thawing and freeze-drying, indicating that most dehydration-induced unfolding was reversible on reconstitution of the freeze-dried protein. In contrast, the tetrameric protein was more susceptible to dehydration-induced denaturation as seen by the greater loss in activity after reconstitution of the freeze-dried samples relative to that measured after freeze-thawing. To ensure optimal protein stability during freeze-drying, the protein must be protected from both freezing and dehydration stresses. Although poly(ethylene glycol) and dextran are preferentially excluded solutes and should confer protection during freezing, they were unable to prevent lyophilization-induced denaturation. In addition, Tween did not foster maintenance of native protein during freeze-drying. However, sucrose, which hydrogen bonds to dried protein in the place of lost water, greatly reduced freezing- and drying-induced denaturation, as observed by the high retention of native

  10. Características estruturais, físico-químicas e funcionais dos amidos de mandioca e de milho com diferentes teores de amilose oxidados por ozônio

    OpenAIRE

    2015-01-01

    A oxidação é um método que visa a modificação do amido por agentes oxidantes diversos, introduzindo grupamentos funcionais e realizando cisão das ligações glicosídicas. Seus objetivos são reduzir a viscosidade do polissacarídeo, elevar a transparência da pasta e limitar sua retrogradação. O objetivo do presente estudo foi modificar os amidos de milho com diferentes teores de amilose e o amido de mandioca pelo tratamento com ozônio e também caracterizar as amostras oxidadas quanto às caracterí...

  11. Extracellular monomeric tau protein is sufficient to initiate the spread of tau protein pathology.

    Science.gov (United States)

    Michel, Claire H; Kumar, Satish; Pinotsi, Dorothea; Tunnacliffe, Alan; St George-Hyslop, Peter; Mandelkow, Eckhard; Mandelkow, Eva-Maria; Kaminski, Clemens F; Kaminski Schierle, Gabriele S

    2014-01-10

    Understanding the formation and propagation of aggregates of the Alzheimer disease-associated Tau protein in vivo is vital for the development of therapeutics for this devastating disorder. Using our recently developed live-cell aggregation sensor in neuron-like cells, we demonstrate that different variants of exogenous monomeric Tau, namely full-length Tau (hTau40) and the Tau-derived construct K18 comprising the repeat domain, initially accumulate in endosomal compartments, where they form fibrillar seeds that subsequently induce the aggregation of endogenous Tau. Using superresolution imaging, we confirm that fibrils consisting of endogenous and exogenous Tau are released from cells and demonstrate their potential to spread Tau pathology. Our data indicate a greater pathological risk and potential toxicity than hitherto suspected for extracellular soluble Tau.

  12. Monomeric GLP-1/GIP/glucagon triagonism corrects obesity, hepatosteatosis, and dyslipidemia in female mice

    DEFF Research Database (Denmark)

    Jall, Sigrid; Sachs, Stephan; Clemmensen, Christoffer

    2017-01-01

    . RESULTS: Our results show that GLP-1/GIP/glucagon triple agonism inhibits food intake and decreases body weight and body fat mass with comparable potency in male and female mice that have been matched for body fat mass. Treatment improved dyslipidemia in both sexes and reversed diet......OBJECTIVE: Obesity is a major health threat that affects men and women equally. Despite this fact, weight-loss potential of pharmacotherapies is typically first evaluated in male mouse models of diet-induced obesity (DIO). To address this disparity we herein determined whether a monomeric peptide...... mice and a cohort of fatmass-matched C57BL/6J male mice were treated for 27 days via subcutaneous injections with either the GLP-1/GIP/glucagon triagonist or PBS. A second cohort of C57BL/6J male mice was included to match the females in the duration of the high-fat, high-sugar diet (HFD) exposure...

  13. Novel Monomeric Phenanthroline—Thallium(Ⅲ) Complexes Multinuclear NMR Characterization in Organic Solvents

    Institute of Scientific and Technical Information of China (English)

    GuiBinMA; JuliusGLASER

    2002-01-01

    A novel complex of monomeric thallium (Ⅲ) with the nitrogen donor ligand phenanthroline (phen) has been prepared and characterized by multimuclear NMR(1H,13C,205Tl). The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the 205Tl NMR spectra. The 1H and 13C NMR spectra of tris-phen T1(Ⅲ) complex have been measured, where the spin-spin coupling between T1(I=1/2) and 13C or 1H signals were observed with the 1H and 13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.

  14. Novel Monomeric Phenanthroline - Thallium(Ⅲ) Complexes Multinuclear NMR Characterization in Organic Solvents

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel complex of monomeric thallium(III) with the nitrogen donor ligand phenanthrolinc (phen) has been prepared and characterized by multinuclear NMR (1H, 13C, 205T1).The three complexes exist in equilibria in DMSO and acetonitrile solution, which was proved by the 205Tl NMR spectra. The 1H and 13C NMR spectra of tris-phen Tl(III) complex have been measured, where the spin-spin coupling between TI (1 = 1/2) and 13C or 1H signals were observed with the 1H and 13C NMR spectroscopy in acetonitrile. The coupling constants are presented and the chemical shifts of complexes are discussed in detail.

  15. Nanocrystalline lanthanide nitride materials synthesised by thermal treatment of amido and ammine metallocenes: X-ray studies and DFT calculations.

    Science.gov (United States)

    Baisch, Ulrich; Pagano, Sandro; Zeuner, Martin; Barros, Noémi; Maron, Laurent; Schnick, Wolfgang

    2006-06-14

    The decomposition process of ammine lanthanide metallocenes was studied by X-ray diffractometry, spectroscopy and theoretical investigations. A series of ammine-tris(eta(5)-cyclopentadienyl)lanthanide(III) complexes 1-Ln (Lanthanide (Ln)=Sm, Gd, Dy, Ho, Er, Yb) was synthesised by the reaction of [Cp(3)Ln] complexes (Cp=cyclopentadienyl) with liquid ammonia at -78 degrees C and structurally characterised by X-ray diffraction methods, mass spectrometry and vibrational (IR, Raman) spectroscopy. Furthermore, amido-bis(eta(5)-cyclopentadienyl)lanthanide(III) complexes 2-Ln (Ln=Dy, Ho, Er, Yb) were synthesised by heating the respective ammine adduct 1-Ln in an inert gas atmosphere at temperatures of between 240 and 290 degrees C. X-ray diffraction studies, mass spectrometry and vibrational (IR, Raman) spectroscopy were carried out for several 2-Ln species and proved the formation of dimeric mu(2)-bridged compounds. Species 1-Ln are highly reactive coordination compounds and showed different behaviour regarding the decomposition to 2-Ln. The reaction of 1-Ln and 2-Ln with inorganic bases yielded lanthanide nitride LnN powders with an estimated crystallite size of between 40 and 90 nm at unprecedented low temperatures of 240 to 300 degrees C. Temperature-dependent X-ray powder diffraction and transmission electron microscopy (TEM) investigations were performed and showed that the decomposition reaction yielded nanocrystalline material. Structural optimisations were carried out for 1-Ln and 2-Ln by employing density functional (DFT) calculations. A good agreement was found between the observed and calculated structural parameters. Also, Gibbs free energies were calculated for 1-Ln, 2-Ln and the pyrolysis reaction to the nitride material, and were found to fit well with the expected ranges.

  16. Kinetics of carbon monoxide binding to monomeric hemoproteins. Role of the proximal histidine.

    Science.gov (United States)

    Coletta, M; Ascenzi, P; Traylor, T G; Brunori, M

    1985-04-10

    The effect of pH on (i) the second-order rate constant for CO binding and (ii) the spectral properties of the deoxygenated derivative of several monomeric hemoproteins has been investigated in the pH range between 2.3 and 9.0. As in the case of 3-[1-imidazolyl]-propylamide monomethyl ester mesoheme, the rate constant for CO binding to sperm whale, horse, Dermochelys coriacea, Coryphaena hippurus, and Aplysia limacina myoglobins (the latter only in the presence of acetate/acetic acid mixture) increases, as the pH is lowered, to a value at least 1 order of magnitude higher than at pH 7.0. Such an effect is not observed in A. limacina myoglobin (in the absence of the acetate/acetic acid mixture) and Chironomus thummi thummi erythrocruorin. Moreover, the absorption spectrum, in the visible region, of the deoxy derivative of all these monomeric hemoproteins (with the exception of A. limacina myoglobin in the absence of the acetate/acetic acid mixture) undergoes a transition as the pH is lowered, an effect observed previously with 3-[1-imidazolyl]-propylamide monomethyl ester protoheme. On the basis of analogous spectroscopic and kinetic properties of chelated heme model compounds we attribute this behavior to the protonation of the N epsilon of the proximal imidazole involved in the bond with the iron atom. On the basis of this model the movement of the iron atom to the heme plane appears as a crucial step for CO binding, the activation free energy of the process amounting to approximately 2 kcal/mol.

  17. 3-Amido pyrrolopyrazine JAK kinase inhibitors: development of a JAK3 vs JAK1 selective inhibitor and evaluation in cellular and in vivo models.

    Science.gov (United States)

    Soth, Michael; Hermann, Johannes C; Yee, Calvin; Alam, Muzaffar; Barnett, Jim W; Berry, Pamela; Browner, Michelle F; Frank, Karl; Frauchiger, Sandra; Harris, Seth; He, Yang; Hekmat-Nejad, Mohammad; Hendricks, Than; Henningsen, Robert; Hilgenkamp, Ramona; Ho, Hoangdung; Hoffman, Ann; Hsu, Pei-Yuan; Hu, Dong-Qing; Itano, Andrea; Jaime-Figueroa, Saul; Jahangir, Alam; Jin, Sue; Kuglstatter, Andreas; Kutach, Alan K; Liao, Cheng; Lynch, Stephen; Menke, John; Niu, Linghao; Patel, Vaishali; Railkar, Aruna; Roy, Douglas; Shao, Ada; Shaw, David; Steiner, Sandra; Sun, Yongliang; Tan, Seng-Lai; Wang, Sandra; Vu, Minh Diem

    2013-01-10

    The Janus kinases (JAKs) are involved in multiple signaling networks relevant to inflammatory diseases, and inhibition of one or more members of this class may modulate disease activity or progression. We optimized a new inhibitor scaffold, 3-amido-5-cyclopropylpyrrolopyrazines, to a potent example with reasonable kinome selectivity, including selectivity for JAK3 versus JAK1, and good biopharmaceutical properties. Evaluation of this analogue in cellular and in vivo models confirmed functional selectivity for modulation of a JAK3/JAK1-dependent IL-2 stimulated pathway over a JAK1/JAK2/Tyk2-dependent IL-6 stimulated pathway.

  18. Amido e farinha de cañihua (Chenopodium pallidicaule): extração, caracterização e desenvolvimento de filmes biodegradáveis

    OpenAIRE

    2016-01-01

    O desenvolvimento de materiais biodegradáveis, a partir de biopolímeros, para embalagens ou coberturas tem grande interesse para a indústria de alimentos. Na elaboração desses materiais, os amidos e as proteínas são muito usados por serem abundantes na natureza, de baixo custo e apresentam propriedades de formar filmes. A cañihua (Chenopodium pallidicaule), grão alto-andino pouco explorado industrialmente, tem altos conteúdos de carboidratos (~58 %) e proteínas (~18 %), e apresenta potencial ...

  19. Filmes poliméricos baseados em amido e lignossulfonatos: preparação, propriedades e avaliação da biodegradação

    Directory of Open Access Journals (Sweden)

    Marina Rodrigues Campagner

    2014-12-01

    Full Text Available Este trabalho envolveu a obtenção de filmes poliméricos a partir de amido de milho e incorporação de lignina na forma de lignossulfonato. A motivação deste trabalho está relacionada à utilização do amido na obtenção de filmes devido ao seu potencial de biodegradação, além do aproveitamento de resíduos de lignossulfonatos provenientes da indústria de celulose e papel. Para a obtenção dos filmes foram utilizados lignossulfonatos em pó e foram realizadas diversas moldagens com variação do tipo e da proporção (1% a 4% de lignossulfonato utilizado. Algumas análises foram realizadas nos filmes poliméricos para comparar propriedades térmicas por DSC (Calorimetria Exploratória Diferencial, e propriedades de tração, em equipamento de DMTA (Análise Térmica Dinâmico-Mecânica. Neste estudo são destacadas as análises da biodegradação e da emissão dos gases liberados utilizando a técnica de Cromatografia Gasosa. De acordo com os resultados de DMTA, a maioria dos filmes poliméricos contendo lignossulfonatos apresentou resistência à tração inferior quando comparados aos filmes poliméricos sem lignossulfonatos (1,024 MPa. Porém, os filmes contendo lignossulfonato modificado com sódio (Vixil S apresentaram maiores valores de resistência à tração quando comparado aos outros filmes contendo os lignossulfonatos utilizados (Vixil I e Vixil Tan. Nas análises térmicas foram notadas semelhanças entre os dois tipos principais de filmes poliméricos (amido; e amido com lignossulfonato, com alguns deslocamentos das temperaturas dos principais picos máximos dos filmes contendo lignossulfonato (4%, Vixil S. Na análise de biodegradabilidade foi verificado que os materiais são biodegradáveis e houve uma emissão maior de CO2 e N2O das amostras dos filmes contendo 4% lignossulfonato do tipo Vixil S, em comparação com as amostras sem lignossulfonato.

  20. Physical, chemical and functional features of apple starch / Propriedades físicas, químicas e funcionais de amido de maçã

    Directory of Open Access Journals (Sweden)

    Gilvan Wosiacki

    2003-05-01

    Full Text Available Physical, chemical and functional features of apple starch. Apple juice contains some chemical agents like starch that may cause long-term turbidity, both in room temperature and refrigerated storage, with depreciation of the commercial value explained by the undesirable appearance. The objective of this article was to characterize some physical, chemical and functional features of purified apple starch as an earlier step aiming to establish the best conditions for its elimination from apple juice, according to routine processing. Apple starch was purified by an alkaline treatment with NaOH 0.15 N and washed with tap water down to neutral pH, and then dried at room temperature. Dry and purified cassava and corn starches were used as standards. Moisture level of apple starch was 13.5 g/100g, crude protein 0.03 g/100g, ash 2.49 g/100g, ether extract 0.04 g/100g and crude fiber 1.56 g/100g. Apple starch was characterized concerning chemical and functional aspects including rheological features like viscoelasticity, clarity and gel strength of the pastes. Apple starch granules in aqueous suspension were submitted to different temperatures aiming to determine their swelling power and solubility. Apple starch granules were also observed in scanning electronic microscope at 3.180x zoom. The results clearly show the apple starch with a functional behavior intermediate to the starches of cassava and of corn used as reference and may be used in order to establish an industrial procedure aiming to remove completely the starch during the processing of clarified apple juice.Os sucos de maçã apresentam agentes causais de turvação, entre eles o amido que, tanto à temperatura ambiente quanto sob refrigeração pode alterar sua aparência, o que determina uma perda de valor econômico do produto. O objetivo deste trabalho foi caracterizar o amido de maçã em relação a propriedades físicas, químicas e funcionais e com isso gerar informações cient

  1. AVALIAÇÃO DAS PROPRIEDADES TÉRMICAS, REOLÓGICAS E ESTRUTURAIS DO AMIDO DE CASTANHA PORTUGUESA (Castanea sativa, Mill) MODIFICADO POR HIDRÓLISE ÁCIDO-ALCOÓLICA

    OpenAIRE

    2016-01-01

    A castanha portuguesa (Castanea sativa, Mill) possui vários nutrientes, sendo o amido o componente principal quimicamente formado por amilose e amilopectina. O amido é a principal substância de reserva para as plantas e a principal fonte energética para o homem, fornecendo de 70 a 80% das calorias diárias necessárias. Está presente em diversas fontes botânicas e pode ser utilizado em diversos setores industriais, sendo um ingrediente importante para os alimentos processados. Pode ser utilizad...

  2. Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

    Science.gov (United States)

    Nelson, Bryant C; Sharpless, Katherine E

    2003-01-29

    Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

  3. Principal component regression analysis of the relation between CIELAB color and monomeric anthocyanins in young Cabernet Sauvignon wines.

    Science.gov (United States)

    Han, Fu-Liang; Zhang, Wen-Na; Pan, Qiu-Hong; Zheng, Cheng-Rong; Chen, Hai-Yan; Duan, Chang-Qing

    2008-11-17

    Color is one of the key characteristics used to evaluate the sensory quality of red wine, and anthocyanins are the main contributors to color. Monomeric anthocyanins and CIELAB color values were investigated by HPLC-MS and spectrophotometry during fermentation of Cabernet Sauvignon red wine, and principal component regression (PCR), a statistical tool, was used to establish a linkage between the detected anthocyanins and wine coloring. The results showed that 14 monomeric anthocyanins could be identified in wine samples, and all of these anthocyanins were negatively correlated with the L*, b* and H*ab values, but positively correlated with a* and C*ab values. On an equal concentration basis for each detected anthocyanin, cyanidin-3-O-glucoside (Cy3-glu) had the most influence on CIELAB color value, while malvidin 3-O-glucoside (Mv3-glu) had the least. The color values of various monomeric anthocyanins were influenced by their structures, substituents on the B-ring, acyl groups on the glucoside and the molecular steric structure. This work develops a statistical method for evaluating correlation between wine color and monomeric anthocyanins, and also provides a basis for elucidating the effect of intramolecular copigmentation on wine coloring.

  4. Principal Component Regression Analysis of the Relation Between CIELAB Color and Monomeric Anthocyanins in Young Cabernet Sauvignon Wines

    Directory of Open Access Journals (Sweden)

    Chang-Qing Duan

    2008-11-01

    Full Text Available Color is one of the key characteristics used to evaluate the sensory quality of red wine, and anthocyanins are the main contributors to color. Monomeric anthocyanins and CIELAB color values were investigated by HPLC-MS and spectrophotometry during fermentation of Cabernet Sauvignon red wine, and principal component regression (PCR, a statistical tool, was used to establish a linkage between the detected anthocyanins and wine coloring. The results showed that 14 monomeric anthocyanins could be identified in wine samples, and all of these anthocyanins were negatively correlated with the L*, b* and H*ab values, but positively correlated with a* and C*ab values. On an equal concentration basis for each detected anthocyanin, cyanidin-3-O-glucoside (Cy3-glu had the most influence on CIELAB color value, while malvidin 3-O-glucoside (Mv3-glu had the least. The color values of various monomeric anthocyanins were influenced by their structures, substituents on the B-ring, acyl groups on the glucoside and the molecular steric structure. This work develops a statistical method for evaluating correlation between wine color and monomeric anthocyanins, and also provides a basis for elucidating the effect of intramolecular copigmentation on wine coloring.

  5. Dinuclear 1,4,7-triazacyclononane (tacn) complexes of cobalt(III) with amido and tacn bridges. Synthesis, characterization and reversible acid-accelerated bridge cleavage

    DEFF Research Database (Denmark)

    Andersen, Peter; Glerup, Jørgen; Gumm, Andreas

    2004-01-01

    Amido-bridged dinuclear cobalt(III) complexes with 1,4,7-triazacyclononane (tacn) were synthesized from [Co(tacn)(O3SCF3)3] by treatment with potassium amide in liquid ammonia at 100 degrees C. Two isomeric triply bridged complexes, [(tacn)Co(mu-NH2)3Co(tacn)]3+ and [(tacn)Co(mu-NH2)2[mu-tacn(-H)......Amido-bridged dinuclear cobalt(III) complexes with 1,4,7-triazacyclononane (tacn) were synthesized from [Co(tacn)(O3SCF3)3] by treatment with potassium amide in liquid ammonia at 100 degrees C. Two isomeric triply bridged complexes, [(tacn)Co(mu-NH2)3Co(tacn)]3+ and [(tacn)Co(mu-NH2)2[mu......)]4+. An isolated perchlorate of this complex appeared to be the salt of the trans-ammineaqua isomer as determined by X-ray diffraction. Equilibration from both sides fits the first-order rate constant dependence k(obs)=6.2(3) x 10(-5)[H+] + 2.1(2) x 10(-5)(s(-1)) at 40 degrees C. Prolonged treatment of the two...

  6. Synthesis and structural characterization of monomeric mercury(II) selenolate complexes derived from 2-phenylbenzamide ligands.

    Science.gov (United States)

    Patel, Saket; Meenakshi; Hodage, Ananda S; Verma, Ajay; Agrawal, Shailendra; Yadav, Abhimanyu; Kumar, Sangit

    2016-03-07

    Monomeric Hg(II) selenolate complexes derived from 2-phenylbenzamide ligands were prepared by oxidative addition of diselenides [{C6H4(CONR2)Se}2, R = Me, Et, iPr] to elemental Hg and reductive cleavage of the Se–N bond of isoselenazolone derivatives [(NO2)C6H3(CONSe)R, (R = allyl, nbutyl)] followed by the treatment with HgCl2. The complexes have been characterized by multinuclear NMR (1H, 13C and 77Se) spectroscopy and mass spectrometry which suggest the monomeric form of these in solution. The molecular structures of diselenides [C6H4(CONR2)Se]2 and mercury selenolates [Hg{(NO2)C6H3(CONH-C3H5) Se}2], [Hg{C6H4(CONiPr2)Se}2] and [Hg{C6H4(CONMe2)Se}2] were established by a single crystal X-ray diffraction study. Diselenides show strong intramolecular non-bonded Se⋯O interactions, which are influenced by the nature of C(O)NR̲2 and decrease with the sterically bulky alkyl substituent (Se⋯O =2.823 Å for R = di-Me, 2.760 Å for R = allyl, and 3.157 Å for R = di-iPr). Mercury complexes derived from less bulky 2-phenyl-N,N-dialkylbenzamide ligands associated with poor or no intramolecular nonbonded Hg⋯O interactions (4.91 Å for R = di-Me, 4.199 Å for R = allyl) and instead strong intermolecular Hg⋯O [2.792(3) and 2.820(4) Å] for di-Me and allyl and Hg⋯Se [3.3212(5) and 3.4076(8) Å] interactions were observed which lead to a dimeric form in the crystals. On the other hand, the mercury complex derived from the sterically bulky diisopropyl amide ligand shows a strong intramolecular non-bonded Hg⋯O (2.860 Å) interaction, adopts linear geometry and exists as a monomer. Thermogravimetric analysis (TGA) of the mercury selenolate complexes revealed two-step decomposition which leads to the formation of HgSe. The mercury selenolate complex 3c derived from the sterically bulky 2-phenyl-N,Ndiisopropylbenzamide ligand decomposed to give HgSe in the range of 220-300 °C.

  7. 11 Efficacy and Tolerability of HDM Injective Immunotherapy With Monomeric Allergoid

    Science.gov (United States)

    Compalati, Enrico; Atzeni, Isabella; Cabras, Sergio; Fancello, Paolo; Gaspardini, Giulio; Longo, Rocco; Patella, Vincenzo; Tore, Giorgio

    2012-01-01

    Background Subcutaneous immunotherapy (SCIT) is an effective treatment of respiratory allergy and carbamylated monomeric allergoids (monoids), by virtue of their reduced IgE-binding activity, resulted clinically safe by sublingual administration. Purpose of this study was to investigate the efficacy and tolerability of immunotherapy with house dust mites (HDM) monoid administered by injective route in patients with allergic rhinoconjunctivitis (AR). Methods A preparation of 0.70 mL of 10 BU/mL containing modified extract with 50% Dermatophagoides pteronyssinus and 50% Dermatophagoides farinae (amount of major allergen: 4 μg of group 1 per milliliter) was delivered monthly for 12 months, following a 5-week build-up induction phase (0.10–0.20–0.30–0.50–0.70 mL), to 58 patients (60% males, mean age 25.1 ± 12.7) suffering from AR due to mites for at least 2 years, whereas 60 patients with similar baseline characteristics were observed as controls. All patients were allowed to assume traditional drug therapy for their condition. At the end of the study changes from baseline in symptoms scores, in number of days with drug assumption, in severity of AR (according to ARIA classification) were compared between the 2 groups; moreover an overall assessment of clinical efficacy and tolerability was based on patients' and physicians' judgements (unsatisfactory, mild, good, optimal). Results In respect to baseline both groups showed, after 1 year, an improvement in symptoms score (P < 0.001) with a significant difference in favour of SCIT group (P < 0.05). Days of drug intake were significantly lower in patients receiving SCIT (P < 0.05). The number of patients with severe AR decreased in the first group while no variation was observed in controls. The subjective clinical overall assessment was optimal in 31 cases and good in 24 according to physicians' and patients' judgements; similarly 38 patients judged tolerability as optimal and 18 as good, whereas according to

  8. Holistic versus monomeric strategies for hydrological modelling of human-modified hydrosystems

    Science.gov (United States)

    Nalbantis, I.; Efstratiadis, A.; Rozos, E.; Kopsiafti, M.; Koutsoyiannis, D.

    2011-03-01

    The modelling of human-modified basins that are inadequately measured constitutes a challenge for hydrological science. Often, models for such systems are detailed and hydraulics-based for only one part of the system while for other parts oversimplified models or rough assumptions are used. This is typically a bottom-up approach, which seeks to exploit knowledge of hydrological processes at the micro-scale at some components of the system. Also, it is a monomeric approach in two ways: first, essential interactions among system components may be poorly represented or even omitted; second, differences in the level of detail of process representation can lead to uncontrolled errors. Additionally, the calibration procedure merely accounts for the reproduction of the observed responses using typical fitting criteria. The paper aims to raise some critical issues, regarding the entire modelling approach for such hydrosystems. For this, two alternative modelling strategies are examined that reflect two modelling approaches or philosophies: a dominant bottom-up approach, which is also monomeric and, very often, based on output information, and a top-down and holistic approach based on generalized information. Critical options are examined, which codify the differences between the two strategies: the representation of surface, groundwater and water management processes, the schematization and parameterization concepts and the parameter estimation methodology. The first strategy is based on stand-alone models for surface and groundwater processes and for water management, which are employed sequentially. For each model, a different (detailed or coarse) parameterization is used, which is dictated by the hydrosystem schematization. The second strategy involves model integration for all processes, parsimonious parameterization and hybrid manual-automatic parameter optimization based on multiple objectives. A test case is examined in a hydrosystem in Greece with high complexities

  9. Holistic versus monomeric strategies for hydrological modelling of human-modified hydrosystems

    Directory of Open Access Journals (Sweden)

    I. Nalbantis

    2011-03-01

    Full Text Available The modelling of human-modified basins that are inadequately measured constitutes a challenge for hydrological science. Often, models for such systems are detailed and hydraulics-based for only one part of the system while for other parts oversimplified models or rough assumptions are used. This is typically a bottom-up approach, which seeks to exploit knowledge of hydrological processes at the micro-scale at some components of the system. Also, it is a monomeric approach in two ways: first, essential interactions among system components may be poorly represented or even omitted; second, differences in the level of detail of process representation can lead to uncontrolled errors. Additionally, the calibration procedure merely accounts for the reproduction of the observed responses using typical fitting criteria. The paper aims to raise some critical issues, regarding the entire modelling approach for such hydrosystems. For this, two alternative modelling strategies are examined that reflect two modelling approaches or philosophies: a dominant bottom-up approach, which is also monomeric and, very often, based on output information, and a top-down and holistic approach based on generalized information. Critical options are examined, which codify the differences between the two strategies: the representation of surface, groundwater and water management processes, the schematization and parameterization concepts and the parameter estimation methodology. The first strategy is based on stand-alone models for surface and groundwater processes and for water management, which are employed sequentially. For each model, a different (detailed or coarse parameterization is used, which is dictated by the hydrosystem schematization. The second strategy involves model integration for all processes, parsimonious parameterization and hybrid manual-automatic parameter optimization based on multiple objectives. A test case is examined in a hydrosystem in Greece

  10. Introduction of ester and amido functions in tetrairon(III) single-molecule magnets: synthesis and physical characterization.

    Science.gov (United States)

    Rodriguez-Douton, Maria Jesus; Cornia, Andrea; Sessoli, Roberta; Sorace, Lorenzo; Barra, Anne-Laure

    2010-07-07

    Tetrairon(III) complexes with a propeller-like structure derived from [Fe(4)(OMe)(6)(dpm)(6)] (1) (Hdpm = 2,2,6,6-tetramethylheptane-3,5-dione) are providing a growing class of Single Molecule Magnets (SMMs) displaying unprecedented synthetic flexibility and ease of functionalization. Herein we report the synthesis, crystal structures and magnetic properties of two novel tetrairon(III) SMMs, [Fe(4)(esterC5)(2)(dpm)(6)] (2) and [Fe(4)(amideC5)(2)(dpm)(6)].Et(2)O.4MeOH (3.Et(2)O.4MeOH), in which functionalization of the cluster core is achieved using ester and amido linkages, respectively. To this aim, two new tripodal ligands were prepared by acylation of pentaerythritol (2,2-bis(hydroxymethyl)propane-1,3-diol) and TRIS (2-amino-2-(hydroxymethyl)propane-1,3-diol), namely H(3)esterC5 = RC(O)OCH(2)C(CH(2)OH)(3) and H(3)amideC5 = RC(O)NHC(CH(2)OH)(3) with R = n-butyl. The compounds were structurally investigated by single-crystal XRD, which demonstrated coordination of the tripodal ligands to the cluster core. The products display SMM behavior with anisotropy barriers U(eff)/k(B) congruent with 11 K due to a high-spin (S = 5) ground state and an easy axis anisotropy, described by D = -0.421 cm(-1) in 2 and -0.414 cm(-1) in 3.Et(2)O.4MeOH. The departure of U(eff) from the total splitting of the S = 5 ground multiplet, U/k(B) congruent with 15 K, has to be ascribed to the sizeable rhombic anisotropy that characterizes the two compounds (E = 0.021 cm(-1) in 2 and 0.019 cm(-1) in 3.Et(2)O.4MeOH), as confirmed by master matrix calculations of the temperature-dependent relaxation time.

  11. A structurally rigid bis(amido) ligand framework in low-coordinate Ni(I), Ni(II), and Ni(III) analogues provides access to a Ni(III) methyl complex via oxidative addition.

    Science.gov (United States)

    Lipschutz, Michael I; Yang, Xinzheng; Chatterjee, Ruchira; Tilley, T Don

    2013-10-16

    A structurally persistent bis-amido ligand framework capable of supporting nickel compounds in three different oxidation states has been identified. A highly unusual, isolable Ni(III) alkyl species has been prepared and characterized via a rare example of a two-electron oxidative addition of MeI to Ni(I).

  12. Avaliação do uso de amidos aniônicos hidrolisados como estabilizantes em nanocápsulas poliméricas para formulações tópicas

    Directory of Open Access Journals (Sweden)

    Ester P. dos Santos

    2013-01-01

    Full Text Available A proposta deste trabalho foi introduzir amidos modificados (aniônicos hidrolisados como tensoativos em uma formulação para a encapsulação da benzofenona-3 com uma matriz polimérica de poli(ε-caprolactona (PCL, avaliando a influência deste componente nas características físico-químicas das nanopartículas. As nanopartículas foram preparadas com a técnica de deposição interfacial do polímero pré-formado, empregando-se um planejamento de experimentos de mistura. Previamente, os amidos foram hidrolisados via processo enzimático e medidas de tensão superficial foram realizadas para avaliar a capacidade tensoativa das soluções aquosas dos amidos hidrolisados para aplicação nas formulações de nanocápsulas. Os resultados indicaram que os amidos avaliados podem ser empregados como tensoativos nas formulações, sem alterar significativamente propriedades, como diâmetro, polidispersão e percentual de encapsulação.

  13. Propriedades de barreira e solubilidade de filmes de amido de ervilha associado com goma xantana e glicerol Barrier properties of films of pea starch associated with xanthan gum and glycerol

    Directory of Open Access Journals (Sweden)

    Manoel D. da Matta Jr

    2011-01-01

    Full Text Available O objetivo do trabalho foi avaliar as propriedades de barreira e a solubilidade de biofilmes obtidos a partir de amido de ervilha de alto teor de amilose em associação à goma xantana e glicerol. Soluções filmogênicas (SF com diferentes teores de amido de ervilha (3, 4 e 5%, goma xantana (0, 0,05 e 0,1% e glicerol (proporção glicerol-amido de 1:5 P/P foram estudadas. As SF foram obtidas por ebulição (5 minutos, seguida de autoclavagem por 1 hora a 120 ºC e os filmes foram preparados por casting. O aumento da concentração de amido e de glicerol na composição causou aumento da espessura e da solubilidade dos filmes em água. O plastificante gerou ainda elevação dos coeficientes de permeabilidade ao vapor d'água e ao oxigênio. O aumento da concentração da goma xantana não interferiu nas propriedades estudadas. Os biofilmes obtidos a partir de amido de ervilha verde, associado ou não à goma xantana e glicerol, se comparados com filmes de amido de ervilha amarelas e outras fontes de amido, apresentaram boa barreira ao oxigênio e ao vapor d'água e baixa solubilidade em água.The aim of this work was to evaluate the barrier properties and solubility of biofilms made from wrinkled pea starch with high amylose content in association with xanthan gum and glycerol. Filmogenic solution (FS with different levels of pea starch (3, 4 and 5%, xanthan gum (0, 0.05 and 0.1% and glycerol (glycerol-starch 1:5 W/W were tested. FS was obtained by boiling (5 minutes, autoclaving for 1 hour at 120 ºC and the films were prepared by casting. The increased concentration of starch and glycerol in the composition caused increases in thickness of the films and in their solubility in water. The plasticizer also generated higher coefficients of water vapor and oxygen permeabilities to water vapor and to oxygen. The increasing concentration of xanthan gum did not interfere in the properties studied. Biofilms produced with wrinkled pea starch, with or

  14. Mapping the dynamics and nanoscale organization of synaptic adhesion proteins using monomeric streptavidin

    Science.gov (United States)

    Chamma, Ingrid; Letellier, Mathieu; Butler, Corey; Tessier, Béatrice; Lim, Kok-Hong; Gauthereau, Isabel; Choquet, Daniel; Sibarita, Jean-Baptiste; Park, Sheldon; Sainlos, Matthieu; Thoumine, Olivier

    2016-01-01

    The advent of super-resolution imaging (SRI) has created a need for optimized labelling strategies. We present a new method relying on fluorophore-conjugated monomeric streptavidin (mSA) to label membrane proteins carrying a short, enzymatically biotinylated tag, compatible with SRI techniques including uPAINT, STED and dSTORM. We demonstrate efficient and specific labelling of target proteins in confined intercellular and organotypic tissues, with reduced steric hindrance and no crosslinking compared with multivalent probes. We use mSA to decipher the dynamics and nanoscale organization of the synaptic adhesion molecules neurexin-1β, neuroligin-1 (Nlg1) and leucine-rich-repeat transmembrane protein 2 (LRRTM2) in a dual-colour configuration with GFP nanobody, and show that these proteins are diffusionally trapped at synapses where they form apposed trans-synaptic adhesive structures. Furthermore, Nlg1 is dynamic, disperse and sensitive to synaptic stimulation, whereas LRRTM2 is organized in compact and stable nanodomains. Thus, mSA is a versatile tool to image membrane proteins at high resolution in complex live environments, providing novel information about the nano-organization of biological structures. PMID:26979420

  15. SuperNova, a monomeric photosensitizing fluorescent protein for chromophore-assisted light inactivation.

    Science.gov (United States)

    Takemoto, Kiwamu; Matsuda, Tomoki; Sakai, Naoki; Fu, Donald; Noda, Masanori; Uchiyama, Susumu; Kotera, Ippei; Arai, Yoshiyuki; Horiuchi, Masataka; Fukui, Kiichi; Ayabe, Tokiyoshi; Inagaki, Fuyuhiko; Suzuki, Hiroshi; Nagai, Takeharu

    2013-01-01

    Chromophore-assisted light inactivation (CALI) is a powerful technique for acute perturbation of biomolecules in a spatio-temporally defined manner in living specimen with reactive oxygen species (ROS). Whereas a chemical photosensitizer including fluorescein must be added to specimens exogenously and cannot be restricted to particular cells or sub-cellular compartments, a genetically-encoded photosensitizer, KillerRed, can be controlled in its expression by tissue specific promoters or subcellular localization tags. Despite of this superiority, KillerRed hasn't yet become a versatile tool because its dimerization tendency prevents fusion with proteins of interest. Here, we report the development of monomeric variant of KillerRed (SuperNova) by direct evolution using random mutagenesis. In contrast to KillerRed, SuperNova in fusion with target proteins shows proper localization. Furthermore, unlike KillerRed, SuperNova expression alone doesn't perturb mitotic cell division. Supernova retains the ability to generate ROS, and hence promote CALI-based functional analysis of target proteins overcoming the major drawbacks of KillerRed.

  16. Hydrogen production from the monomeric sugars hydrolyzed from hemicellulose by Enterobacter aerogenes

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yunli; Wang, Jianji; Liu, Zhen; Ren, Yunlai; Li, Guozhi [School of Chemical Engineering and Pharmaceutics, Henan University of Science and Technology, Luoyang 471039, Henan (China)

    2009-12-15

    Relatively large percentages of xylose with glucose, arabinose, mannose, galactose and rhamnose constitute the hydrolysis products of hemicellulose. In this paper, hydrogen production performance of facultative anaerobe (Enterobacter aerogenes) has been investigated from these different monomeric sugars except glucose. It was shown that the stereoisomers of mannose and galactose were more effective for hydrogen production than those of xylose and arabinose. The substrate of 5 g/l xylose resulted in a relative high level of hydrogen yield (73.8 mmol/l), hydrogen production efficiency (2.2 mol/mol) and a maximum hydrogen production rate (249 ml/l/h). The hydrogen yield, hydrogen production efficiency and the maximum hydrogen production rate reached 104 mmol/l, 2.35 mol/mol and 290 ml/l/h, respectively, on a substrate of 10 g/l galactose. The hydrogen yields and the maximum hydrogen production rates increased with an increase of mannose concentrations and reached 119 mmol/l and 518 ml/l/h on the culture of 25 g/l mannose. However, rhamnose was a relative poor carbon resource for E. aerogenes to produce hydrogen, from which the hydrogen yield and hydrogen production efficiency were about one half of that from the mannose substrate. E. aerogenes was found to be a promising strain for hydrogen production from hydrolysis products of hemicellulose. (author)

  17. Generation of transgenic Wuzhishan miniature pigs expressing monomeric red fluorescent protein by somatic cell nuclear transfer.

    Science.gov (United States)

    Lu, Yue; Kang, Jin-Dan; Li, Suo; Wang, Wei; Jin, Jun-Xue; Hong, Yu; Cui, Cheng-du; Yan, Chang-Guo; Yin, Xi-Jun

    2013-08-01

    Red fluorescent protein and its variants enable researchers to study gene expression, localization, and protein-protein interactions in vitro in real-time. Fluorophores with higher wavelengths are usually preferred since they efficiently penetrate tissues and produce less toxic emissions. A recently developed fluorescent protein marker, monomeric red fluorescent protein (mRFP1), is particularly useful because of its rapid maturation and minimal interference with green fluorescent protein (GFP) and GFP-derived markers. We generated a pCX-mRFP1-pgk-neoR construct and evaluated the ability of mRFP1 to function as a fluorescent marker in transgenic Wuzhishan miniature pigs. Transgenic embryos were generated by somatic cell nuclear transfer (SCNT) of nuclei isolated from ear fibroblasts expressing mRFP1. Embryos generated by SCNT developed into blastocysts in vitro (11.65%; 31/266). Thereafter, a total of 685 transgenic embryos were transferred into the oviducts of three recipients, two of which became pregnant. Of these, one recipient had six aborted fetuses, whereas the other recipient gave birth to four offspring. All offspring expressed the pCX-mRFP1-pgk-neoR gene as shown by PCR and fluorescence in situ hybridization analysis. The transgenic pigs expressed mRFP1 in all organs and tissues at high levels. These results demonstrate that Wuzhishan miniature pigs can express mRFP1. To conclude, this transgenic animal represents an excellent model with widespread applications in medicine and agriculture.

  18. Retention mechanism for polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography with monomeric stationary phases.

    Science.gov (United States)

    Rafferty, Jake L; Siepmann, J Ilja; Schure, Mark R

    2011-12-23

    Reversed-phase liquid chromatography (RPLC) is the foremost technique for the separation of analytes that have very similar chemical functionalities, but differ only in their molecular shape. This ability is crucial in the analysis of various mixtures with environmental and biological importance including polycyclic aromatic hydrocarbons (PAHs) and steroids. A large amount of effort has been devoted to studying this phenomenon experimentally, but a detailed molecular-level description remains lacking. To provide some insight on the mechanism of shape selectivity in RPLC, particle-based simulations were carried out for stationary phases and chromatographic parameters that closely mimic those in an experimental study by Sentell and Dorsey [J. Chromatogr. 461 (1989) 193]. The retention of aromatic hydrocarbons ranging in size from benzene to the isomeric PAHs of the formula C(18)H(12) was examined for model RPLC systems consisting of monomeric dimethyl octadecylsilane (ODS) stationary phases with surface coverages ranging from 1.6 to 4.2 μmol/m(2) (i.e., stationary phases yielding low to intermediate shape selectivity) in contact with a 67/33 mol% acetonitrile/water mobile phase. The simulations show that the stationary phase acts as a very heterogeneous environment where analytes with different shapes prefer different spatial regions with specific local bonding environments of the ODS chains. However, these favorable retentive regions cannot be described as pre-existing cavities because the chain conformation in these local stationary phase regions adapts to accommodate the analytes.

  19. Model of a DNA-protein complex of the architectural monomeric protein MC1 from Euryarchaea.

    Directory of Open Access Journals (Sweden)

    Françoise Paquet

    Full Text Available In Archaea the two major modes of DNA packaging are wrapping by histone proteins or bending by architectural non-histone proteins. To supplement our knowledge about the binding mode of the different DNA-bending proteins observed across the three domains of life, we present here the first model of a complex in which the monomeric Methanogen Chromosomal protein 1 (MC1 from Euryarchaea binds to the concave side of a strongly bent DNA. In laboratory growth conditions MC1 is the most abundant architectural protein present in Methanosarcina thermophila CHTI55. Like most proteins that strongly bend DNA, MC1 is known to bind in the minor groove. Interaction areas for MC1 and DNA were mapped by Nuclear Magnetic Resonance (NMR data. The polarity of protein binding was determined using paramagnetic probes attached to the DNA. The first structural model of the DNA-MC1 complex we propose here was obtained by two complementary docking approaches and is in good agreement with the experimental data previously provided by electron microscopy and biochemistry. Residues essential to DNA-binding and -bending were highlighted and confirmed by site-directed mutagenesis. It was found that the Arg25 side-chain was essential to neutralize the negative charge of two phosphates that come very close in response to a dramatic curvature of the DNA.

  20. An Intrinsically Disordered Motif Mediates Diverse Actions of Monomeric C-reactive Protein.

    Science.gov (United States)

    Li, Hai-Yun; Wang, Jing; Meng, Fan; Jia, Zhe-Kun; Su, Yang; Bai, Qi-Feng; Lv, Ling-Ling; Ma, Fu-Rong; Potempa, Lawrence A; Yan, Yong-Bin; Ji, Shang-Rong; Wu, Yi

    2016-04-15

    Most proinflammatory actions of C-reactive protein (CRP) are only expressed following dissociation of its native pentameric assembly into monomeric form (mCRP). However, little is known about what underlies the greatly enhanced activities of mCRP. Here we show that a single sequence motif, i.e. cholesterol binding sequence (CBS; a.a. 35-47), is responsible for mediating the interactions of mCRP with diverse ligands. The binding of mCRP to lipoprotein component ApoB, to complement component C1q, to extracellular matrix components fibronectin and collagen, to blood coagulation component fibrinogen, and to membrane lipid component cholesterol, are all found to be markedly inhibited by the synthetic CBS peptide but not by other CRP sequences tested. Likewise, mutating CBS in mCRP also greatly impairs these interactions. Functional experiments further reveal that CBS peptide significantly reduces the effects of mCRP on activation of endothelial cells in vitro and on acute induction of IL-6 in mice. The potency and specificity of CBS are critically determined by the N-terminal residues Cys-36, Leu-37, and His-38; while the versatility of CBS appears to originate from its intrinsically disordered conformation polymorphism. Together, these data unexpectedly identify CBS as the major recognition site of mCRP and suggest that this motif may be exploited to tune the proinflammatory actions of mCRP.

  1. Design of monomeric water-soluble β-hairpin and β-sheet peptides.

    Science.gov (United States)

    Jiménez, M Angeles

    2014-01-01

    Since the first report in 1993 (JACS 115, 5887-5888) of a peptide able to form a monomeric β-hairpin structure in aqueous solution, the design of peptides forming either β-hairpins (two-stranded antiparallel β-sheets) or three-stranded antiparallel β-sheets has become a field of growing interest and activity. These studies have yielded great insights into the principles governing the stability and folding of β-hairpins and antiparallel β-sheets. This chapter provides an overview of the reported β-hairpin/β-sheet peptides focussed on the applied design criteria, reviews briefly the factors contributing to β-hairpin/β-sheet stability, and describes a protocol for the de novo design of β-sheet-forming peptides based on them. Guidelines to select appropriate turn and strand residues and to avoid self-association are provided. The methods employed to check the success of new designed peptides are also summarized. Since NMR is the best technique to that end, NOEs and chemical shifts characteristic of β-hairpins and three-stranded antiparallel β-sheets are given.

  2. Lipoamino acid-based micelles as promising delivery vehicles for monomeric amphotericin B.

    Science.gov (United States)

    Serafim, Cláudia; Ferreira, Inês; Rijo, Patrícia; Pinheiro, Lídia; Faustino, Célia; Calado, António; Garcia-Rio, Luis

    2016-01-30

    Lipoamino acid-based micelles have been developed as delivery vehicles for the hydrophobic drug amphotericin B (AmB). The micellar solubilisation of AmB by a gemini lipoamino acid (LAA) derived from cysteine and its equimolar mixtures with the bile salts sodium cholate (NaC) and sodium deoxycholate (NaDC), as well as the aggregation sate of the drug in the micellar systems, was studied under biomimetic conditions (phosphate buffered-saline, pH 7.4) using UV-vis spectroscopy. Pure surfactant systems and equimolar mixtures were characterized by tensiometry and important parameters were determined, such as critical micelle concentration (CMC), surface tension at the CMC (γCMC), maximum surface excess concentration (Γmax), and minimum area occupied per molecule at the water/air interface (Amin). Rheological behaviour from viscosity measurements at different shear rates was also addressed. Solubilisation capacity was quantified in terms of molar solubilisation ratio (χ), micelle-water partition coefficient (KM) and Gibbs energy of solubilisation (ΔGs°). Formulations of AmB in micellar media were compared in terms of drug loading, encapsulation efficiency, aggregation state of AmB and in vitro antifungal activity against Candida albicans. The LAA-containing micellar systems solubilise AmB in its monomeric and less toxic form and exhibit in vitro antifungal activity comparable to that of the commercial formulation Fungizone.

  3. Heterolytic cleavage of ammonia N-H bond by bifunctional activation in silica-grafted single site Ta(V) imido amido surface complex. Importance of the outer sphere NH3 assistance

    KAUST Repository

    Gouré, Eric

    2011-01-01

    Ammonia N-H bond is cleaved at room temperature by the silica-supported tantalum imido amido complex [(≡SiO)2Ta(NH)(-NH2)], 2, if excess ammonia is present, but requires 150 °C to achieve the same reaction if only one equivalent NH3 is added to 2. MAS solid-state 15N NMR and in situ IR spectroscopic studies of the reaction of either 15N or 2H labeled ammonia with 2 show that initial coordination of the ammonia is followed by scrambling of either 15N or 2H among ammonia, amido and imido groups. Density functional theory (DFT) calculations with a cluster model [{(μ-O)[(H3SiO) 2SiO]2}Ta(NH)(-NH2)(NH3)], 2 q·NH3, show that the intramolecular H transfer from Ta-NH2 to TaNH is ruled out, but the H transfers from the coordinated ammonia to the amido and imido groups have accessible energy barriers. The energy barrier for the ammonia N-H activation by the Ta-amido group is energetically preferred relative to the Ta-imido group. The importance of excess NH3 for getting full isotope scrambling is rationalized by an outer sphere assistance of ammonia acting as proton transfer agent, which equalizes the energy barriers for H transfer from coordinated ammonia to the amido and imido groups. In contrast, additional coordinated ammonia does not favor significantly the H transfer. These results rationalize the experimental conditions used. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011.

  4. Effect of enzymatic hydrolysis on some physicochemical properties of root and tuber granular starches Efeito da hidrólise enzimática sobre algumas propriedades físico-químicas de amidos de raízes e tubérculos

    Directory of Open Access Journals (Sweden)

    Thaís de Souza Rocha

    2010-06-01

    Full Text Available Enzymatic hydrolysis of granular starch is an important tool to provide information about granule structure. Cassava, sweet potato, Peruvian carrot, and potato starches were hydrolyzed by bacterial α-amylase at 37 °C for 48 hours, and the physicochemical properties of the residues from hydrolysis were determined. Cassava starch was the most susceptible to enzyme displaying 20.9% of hydrolysis, whereas potato starch was the most resistant with 5.9%. The granule average size varied from 10.8 to 23.4 μm for Peruvian carrot and potato starches, respectively. With the use of SEM, a smooth granule surface was observed for all native starches. Cassava and sweet potato starches displayed an A-type X-ray diffraction pattern, while Peruvian carrot and potato starches showed a B-type pattern. After hydrolysis, cassava, sweet potato, and Peruvian carrot starches showed some well degraded granules, whereas potato starch presented a slight sign of degradation. The amylose content of the starches decreased with hydrolysis for cassava, sweet potato, and Peruvian carrot starches and was kept unchanged for the potato starch. As expected, intrinsic viscosity and pasting properties decreased for all hydrolyzed starches. There is no difference between thermal properties of native and hydrolyzed starches. These results suggested that hydrolysis occurred in amorphous and crystalline areas of the granules. The B type diffraction pattern in conjunction with the big granule size of the potato starch may have contributed to the greatest resistance of this starch to hydrolysis.A hidrólise enzimática do amido pode fornecer informações importantes sobre sua estrutura granular. Amidos de mandioca, batata-doce, mandioquinha-salsa e batata foram hidrolisados por α-amilase bacteriana a 37 °C durante 48 horas, e algumas propriedades físico-químicas dos resíduos da hidrólise foram determinadas. O amido de mandioca foi o mais suscetível à enzima com 20,9% de hidr

  5. Starch films: production, properties and potential of utilization / Filmes de amido: produção, propriedades e potencial de utilização

    Directory of Open Access Journals (Sweden)

    Fábio Yamashita

    2010-04-01

    Full Text Available There is an increasing interest in the utilization of renewable resources for the production of food packaging. Among the biopolymers, starches from several sources have been considered as one of the most promising material for this purpose, and the reasons for this are that starches are biodegradable, are inexpensive and available in the worldwide. This work presents a bibliography review about biodegradable starch films characterization and potential of utilization. Discusses the starch films mechanical and barrier properties, the cristallinity and the effects of the use of plasticizers over these properties. The discussed informations indicate that exist great possibilities for these materials in food packaging, which depend on the production of more stable materials and the development of production technology in industrial scale.O interesse no emprego de matérias-primas provenientes de recursos renováveis para a produção de embalagens de alimentos vem crescendo. Dentre os biopolímeros mais promissores para este fim estão os amidos de diversas fontes botânicas, que são biodegradáveis, têm custo baixo e estão disponíveis em todo o mundo. Diante disto, este trabalho apresenta uma revisão bibliográfica sobre a caracterização e o potencial de utilização de filmes biodegradáveis a base de amido. Discute as propriedades mecânicas, de barreira e a cristalinidade dos filmes de amido e o efeito do uso de plastificantes sobre estas propriedades. As informações disponibilizadas mostram que existem grandes possibilidades de utilização destes materiais como embalagens de alimentos que, no entanto, dependem da produção de materiais mais estáveis às condições de armazenamento e do desenvolvimento de tecnologia de produção em escala industrial.

  6. Monomeric malonate precursors for the MOCVD of HfO2 and ZrO2 thin films.

    Science.gov (United States)

    Pothiraja, Ramasamy; Milanov, Andrian; Parala, Harish; Winter, Manuela; Fischer, Roland A; Devi, Anjana

    2009-01-28

    New Hf and Zr malonate complexes have been synthesized by the reaction of metal amides with different malonate ligands (L = dimethyl malonate (Hdmml), diethyl malonate (Hdeml), di-tert-butyl malonate (Hdbml) and bis(trimethylsilyl) malonate (Hbsml)). Homoleptic eight-coordinated monomeric compounds of the type ML4 were obtained for Hf with all the malonate ligands employed. In contrast, for Zr only Hdmml and Hdeml yielded the eight-coordinated monomeric compounds of the type ML4, while using the bulky Hdbml and Hbsml ligands resulted into mixed alkoxo-malonato six-coordinated compounds of the type [ML2(OR)2]. Single crystal X-ray diffraction studies of all the compounds are presented and discussed, and they are found to be monomeric. The complexes are solids and in solution, they retain their monomeric nature as evidenced by NMR measurements. Compared to the classical beta-diketonate complexes, [M(acac)4] and [M(thd)4] (M = Hf, Zr; acac: acetylacetonate; thd: tetramethylheptadione), the new malonate compounds are more volatile, decompose at lower temperatures and have lower melting points. In particular, the homoleptic diethyl malonate complexes of Hf and Zr melt at temperatures as low as 62 degrees C. In addition, the compounds are very stable in air and can be sublimed quantitatively. The promising thermal properties makes these compounds interesting for metal-organic chemical vapor deposition (MOCVD). This was demonstrated by depositing HfO2 and ZrO2 thin films successfully with two representative Hf and Zr complexes.

  7. Neurodevelopmental Expression Profile of Dimeric and Monomeric Group 1 mGluRs: Relevance to Schizophrenia Pathogenesis and Treatment

    Science.gov (United States)

    Lum, Jeremy S.; Fernandez, Francesca; Matosin, Natalie; Andrews, Jessica L.; Huang, Xu-Feng; Ooi, Lezanne; Newell, Kelly A.

    2016-01-01

    Group 1 metabotropic glutamate receptors (mGluR1/mGluR5) play an integral role in neurodevelopment and are implicated in psychiatric disorders, such as schizophrenia. mGluR1 and mGluR5 are expressed as homodimers, which is important for their functionality and pharmacology. We examined the protein expression of dimeric and monomeric mGluR1α and mGluR5 in the prefrontal cortex (PFC) and hippocampus throughout development (juvenile/adolescence/adulthood) and in the perinatal phencyclidine (PCP) model of schizophrenia. Under control conditions, mGluR1α dimer expression increased between juvenile and adolescence (209–328%), while monomeric levels remained consistent. Dimeric mGluR5 was steadily expressed across all time points; monomeric mGluR5 was present in juveniles, dramatically declining at adolescence and adulthood (−97–99%). The mGluR regulators, Homer 1b/c and Norbin, significantly increased with age in the PFC and hippocampus. Perinatal PCP treatment significantly increased juvenile dimeric mGluR5 levels in the PFC and hippocampus (37–50%) but decreased hippocampal mGluR1α (−50–56%). Perinatal PCP treatment also reduced mGluR1α dimer levels in the PFC at adulthood (−31%). These results suggest that Group 1 mGluRs have distinct dimeric and monomeric neurodevelopmental patterns, which may impact their pharmacological profiles at specific ages. Perinatal PCP treatment disrupted the early expression of Group 1 mGluRs which may underlie neurodevelopmental alterations observed in this model. PMID:27721389

  8. Monomerization of viral entry inhibitor griffithsin elucidates the relationship between multivalent binding to carbohydrates and anti-HIV activity.

    Science.gov (United States)

    Moulaei, Tinoush; Shenoy, Shilpa R; Giomarelli, Barbara; Thomas, Cheryl; McMahon, James B; Dauter, Zbigniew; O'Keefe, Barry R; Wlodawer, Alexander

    2010-09-08

    Mutations were introduced to the domain-swapped homodimer of the antiviral lectin griffithsin (GRFT). Whereas several single and double mutants remained dimeric, insertion of either two or four amino acids at the dimerization interface resulted in a monomeric form of the protein (mGRFT). Monomeric character of the modified proteins was confirmed by sedimentation equilibrium ultracentrifugation and by their high resolution X-ray crystal structures, whereas their binding to carbohydrates was assessed by isothermal titration calorimetry. Cell-based antiviral activity assays utilizing different variants of mGRFT indicated that the monomeric form of the lectin had greatly reduced activity against HIV-1, suggesting that the antiviral activity of GRFT stems from crosslinking and aggregation of viral particles via multivalent interactions between GRFT and oligosaccharides present on HIV envelope glycoproteins. Atomic resolution crystal structure of a complex between mGRFT and nonamannoside revealed that a single mGRFT molecule binds to two different nonamannoside molecules through all three carbohydrate-binding sites present on the monomer.

  9. Identification of the chromophores involved in aggregation-dependent energy quenching of the monomeric photosystem II antenna protein Lhcb5.

    Science.gov (United States)

    Ballottari, Matteo; Girardon, Julien; Betterle, Nico; Morosinotto, Tomas; Bassi, Roberto

    2010-09-03

    Non-photochemical quenching (NPQ) of excess absorbed light energy is a fundamental process that regulates photosynthetic light harvesting in higher plants. Among several proposed NPQ mechanisms, aggregation-dependent quenching (ADQ) and charge transfer quenching have received the most attention. In vitro spectroscopic features of both mechanisms correlate with very similar signals detected in more intact systems and in vivo, where full NPQ can be observed. A major difference between the models is the proposed quenching site, which is predominantly the major trimeric light-harvesting complex II in ADQ and exclusively monomeric Lhcb proteins in charge transfer quenching. Here, we studied ADQ in both monomeric and trimeric Lhcb proteins, investigating the activities of each antenna subunit and their dependence on zeaxanthin, a major modulator of NPQ in vivo. We found that monomeric Lhcb proteins undergo stronger quenching than light-harvesting complex II during aggregation and that this is enhanced by binding to zeaxanthin, as occurs during NPQ in vivo. Finally, the analysis of Lhcb5 mutants showed that chlorophyll 612 and 613, in close contact with lutein bound at site L1, are important facilitators of ADQ.

  10. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... to elicit antibodies preferentially neutralizing mutant variants of HIV-BRU lacking the N306 glycan. Therefore, two guinea pigs were immunized with monomeric wild-type HIV-BRU gp120 possessing the N306 glycan and immune sera were tested for neutralization against target viruses HIV-BRU, -A308, and -A308T321....... HIV-A308 and HIV-A308T321 lack the N306 glycan; HIV-A308T321 contains an additional mutation at the tip of V3 rendering it resistant to MAb binding at this epitope. Both immune sera preferentially neutralized the two mutant virus variants lacking the N306 glycan, with a 10- to 20-fold increase...

  11. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... to elicit antibodies preferentially neutralizing mutant variants of HIV-BRU lacking the N306 glycan. Therefore, two guinea pigs were immunized with monomeric wild-type HIV-BRU gp120 possessing the N306 glycan and immune sera were tested for neutralization against target viruses HIV-BRU, -A308, and -A308T321....... HIV-A308 and HIV-A308T321 lack the N306 glycan; HIV-A308T321 contains an additional mutation at the tip of V3 rendering it resistant to MAb binding at this epitope. Both immune sera preferentially neutralized the two mutant virus variants lacking the N306 glycan, with a 10- to 20-fold increase...

  12. Monomeric and gemini surfactants as antimicrobial agents - influence on environmental and reference strains.

    Science.gov (United States)

    Koziróg, Anna; Brycki, Bogumił

    2015-01-01

    Quaternary ammonium salts (QAS) belong to surfactant commonly used both, in the household and in different branches of industry, primarily in the process of cleaning and disinfection. They have several positive features inter alia effectively limiting the development of microorganisms on many surfaces. In the present work, two compounds were used as biocides: hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) that belongs to the gemini surfactant (GS), and its single analogue - dodecyl(trimethyl)ammonium bromide (DTAB). Two fold dilution method was used to determine the minimum concentration of compounds (MIC) which inhibit the growth of bacteria: Staphylococcus aureus (ATCC 6538 and an environmental strain), Pseudomonas aeruginosa (ATCC 85327 and an environmental strain), and yeast Candida albicans (ATCC 11509 and an environmental strain). The viability of cells in liquid cultures with addition of these substances at ¼ MIC, ½ MIC and MIC concentrations were also determined. The obtained results show that DTAB inhibits the growth of bacteria at the concentration of 0.126-1.010 µM/ml, and gemini surfactant is active at 0.036-0.029 µM/ml. Therefore, GS is active at more than 17-70-fold lower concentrations than its monomeric analogue. Strains isolated from natural environment are less sensitive upon testing biocides than the references strains. Both compounds at the MIC value reduced the number of cells of all strains. The use of too low concentration of biocides can limit the growth of microorganisms, but often only for a short period of time in case of special environmental strains. Later on, they can adapt to adverse environmental conditions and begin to evolve defence mechanisms.

  13. Production of transgenic cloned pigs expressing the far-red fluorescent protein monomeric Plum.

    Science.gov (United States)

    Watanabe, Masahito; Kobayashi, Mirina; Nagaya, Masaki; Matsunari, Hitomi; Nakano, Kazuaki; Maehara, Miki; Hayashida, Gota; Takayanagi, Shuko; Sakai, Rieko; Umeyama, Kazuhiro; Watanabe, Nobuyuki; Onodera, Masafumi; Nagashima, Hiroshi

    2015-01-01

    Monomeric Plum (Plum), a far-red fluorescent protein with photostability and photopermeability, is potentially suitable for in vivo imaging and detection of fluorescence in body tissues. The aim of this study was to generate transgenic cloned pigs exhibiting systemic expression of Plum using somatic cell nuclear transfer (SCNT) technology. Nuclear donor cells for SCNT were obtained by introducing a Plum-expression vector driven by a combination of the cytomegalovirus early enhancer and chicken beta-actin promoter into porcine fetal fibroblasts (PFFs). The cleavage and blastocyst formation rates of reconstructed SCNT embryos were 81.0% (34/42) and 78.6% (33/42), respectively. At 36-37 days of gestation, three fetuses systemically expressing Plum were obtained from one recipient to which 103 SCNT embryos were transferred (3/103, 2.9%). For generation of offspring expressing Plum, rejuvenated PFFs were established from one cloned fetus and used as nuclear donor cells. Four cloned offspring and one stillborn cloned offspring were produced from one recipient to which 117 SCNT embryos were transferred (5/117, 4.3%). All offspring exhibited high levels of Plum fluorescence in blood cells, such as lymphocytes, monocytes and granulocytes. In addition, the skin, heart, kidney, pancreas, liver and spleen also exhibited Plum expression. These observations demonstrated that transfer of the Plum gene did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of transgenic cloned pigs that systemically expressed Plum. This is the first report of the generation and characterization of transgenic cloned pigs expressing the far-red fluorescent protein Plum.

  14. Crystal structure of a monomeric thiolase-like protein type 1 (TLP1 from Mycobacterium smegmatis.

    Directory of Open Access Journals (Sweden)

    Neelanjana Janardan

    Full Text Available An analysis of the Mycobacterium smegmatis genome suggests that it codes for several thiolases and thiolase-like proteins. Thiolases are an important family of enzymes that are involved in fatty acid metabolism. They occur as either dimers or tetramers. Thiolases catalyze the Claisen condensation of two acetyl-Coenzyme A molecules in the synthetic direction and the thiolytic cleavage of 3-ketoacyl-Coenzyme A molecules in the degradative direction. Some of the M. smegmatis genes have been annotated as thiolases of the poorly characterized SCP2-thiolase subfamily. The mammalian SCP2-thiolase consists of an N-terminal thiolase domain followed by an additional C-terminal domain called sterol carrier protein-2 or SCP2. The M. smegmatis protein selected in the present study, referred to here as the thiolase-like protein type 1 (MsTLP1, has been biochemically and structurally characterized. Unlike classical thiolases, MsTLP1 is a monomer in solution. Its structure has been determined at 2.7 Å resolution by the single wavelength anomalous dispersion method. The structure of the protomer confirms that the N-terminal domain has the thiolase fold. An extra C-terminal domain is indeed observed. Interestingly, it consists of six β-strands forming an anti-parallel β-barrel which is completely different from the expected SCP2-fold. Detailed sequence and structural comparisons with thiolases show that the residues known to be essential for catalysis are not conserved in MsTLP1. Consistent with this observation, activity measurements show that MsTLP1 does not catalyze the thiolase reaction. This is the first structural report of a monomeric thiolase-like protein from any organism. These studies show that MsTLP1 belongs to a new group of thiolase related proteins of unknown function.

  15. Purification and biochemical characterization of a monomeric form of papaya mosaic potexvirus coat protein.

    Science.gov (United States)

    Lecours, Katia; Tremblay, Marie-Hélène; Gagné, Marie-Eve Laliberté; Gagné, Stéphane M; Leclerc, Denis

    2006-05-01

    Papaya mosaic virus (PapMV) is a flexuous rod shape virus made of 1400 subunits that assemble around a plus sense genomic RNA. The structure determination of PapMV and of flexuous viruses in general is a major challenge for both NMR and X-ray crystallography. In this report, we present the characterization of a truncated version of the PapMV coat protein (CP) that is suitable for NMR study. The deletion of the N-terminal 26 amino acids of the PapMV CP (CP27-215) generates a monomer that can be expressed to high level and easily purified for production of an adequate NMR sample. The RNA gel shift assay showed that CP27-215 lost its ability to bind RNA in vitro, suggesting that the multimerization of the subunit is important for this function. The fusion of a 6x His tag at the C-terminus improved the solubility of the monomer and allowed its concentration to 0.2 mM. The CD spectra of the truncated and the wild-type proteins were similar, suggesting that both proteins are well ordered and have a similar secondary structure. CP27-215 was 15N labeled for NMR studies and a 2D 1H-15N-HSQC spectrum confirmed the presence of a well-ordered structure and the monomeric form of the protein. These results show that CP27-215 is amenable to a complete and exhaustive NMR study that should lead to the first three-dimensional structure determination of a flexuous rod shape virus.

  16. Production of transgenic cloned pigs expressing the far-red fluorescent protein monomeric Plum

    Science.gov (United States)

    WATANABE, Masahito; KOBAYASHI, Mirina; NAGAYA, Masaki; MATSUNARI, Hitomi; NAKANO, Kazuaki; MAEHARA, Miki; HAYASHIDA, Gota; TAKAYANAGI, Shuko; SAKAI, Rieko; UMEYAMA, Kazuhiro; WATANABE, Nobuyuki; ONODERA, Masafumi; NAGASHIMA, Hiroshi

    2015-01-01

    Monomeric Plum (Plum), a far-red fluorescent protein with photostability and photopermeability, is potentially suitable for in vivo imaging and detection of fluorescence in body tissues. The aim of this study was to generate transgenic cloned pigs exhibiting systemic expression of Plum using somatic cell nuclear transfer (SCNT) technology. Nuclear donor cells for SCNT were obtained by introducing a Plum-expression vector driven by a combination of the cytomegalovirus early enhancer and chicken beta-actin promoter into porcine fetal fibroblasts (PFFs). The cleavage and blastocyst formation rates of reconstructed SCNT embryos were 81.0% (34/42) and 78.6% (33/42), respectively. At 36–37 days of gestation, three fetuses systemically expressing Plum were obtained from one recipient to which 103 SCNT embryos were transferred (3/103, 2.9%). For generation of offspring expressing Plum, rejuvenated PFFs were established from one cloned fetus and used as nuclear donor cells. Four cloned offspring and one stillborn cloned offspring were produced from one recipient to which 117 SCNT embryos were transferred (5/117, 4.3%). All offspring exhibited high levels of Plum fluorescence in blood cells, such as lymphocytes, monocytes and granulocytes. In addition, the skin, heart, kidney, pancreas, liver and spleen also exhibited Plum expression. These observations demonstrated that transfer of the Plum gene did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of transgenic cloned pigs that systemically expressed Plum. This is the first report of the generation and characterization of transgenic cloned pigs expressing the far-red fluorescent protein Plum. PMID:25739316

  17. Structural Analysis of Monomeric RNA-Dependent Polymerases: Evolutionary and Therapeutic Implications.

    Directory of Open Access Journals (Sweden)

    Rodrigo Jácome

    Full Text Available The crystal structures of monomeric RNA-dependent RNA polymerases and reverse transcriptases of more than 20 different viruses are available in the Protein Data Bank. They all share the characteristic right-hand shape of DNA- and RNA polymerases formed by the fingers, palm and thumb subdomains, and, in many cases, "fingertips" that extend from the fingers towards the thumb subdomain, giving the viral enzyme a closed right-hand appearance. Six conserved structural motifs that contain key residues for the proper functioning of the enzyme have been identified in all these RNA-dependent polymerases. These enzymes share a two divalent metal-ion mechanism of polymerization in which two conserved aspartate residues coordinate the interactions with the metal ions to catalyze the nucleotidyl transfer reaction. The recent availability of crystal structures of polymerases of the Orthomyxoviridae and Bunyaviridae families allowed us to make pairwise comparisons of the tertiary structures of polymerases belonging to the four main RNA viral groups, which has led to a phylogenetic tree in which single-stranded negative RNA viral polymerases have been included for the first time. This has also allowed us to use a homology-based structural prediction approach to develop a general three-dimensional model of the Ebola virus RNA-dependent RNA polymerase. Our model includes several of the conserved structural motifs and residues described in other viral RNA-dependent RNA polymerases that define the catalytic and highly conserved palm subdomain, as well as portions of the fingers and thumb subdomains. The results presented here help to understand the current use and apparent success of antivirals, i.e. Brincidofovir, Lamivudine and Favipiravir, originally aimed at other types of polymerases, to counteract the Ebola virus infection.

  18. One-pot chemical synthesis of small ubiquitin-like modifier protein-peptide conjugates using bis(2-sulfanylethyl)amido peptide latent thioester surrogates.

    Science.gov (United States)

    Boll, Emmanuelle; Drobecq, Hervé; Ollivier, Nathalie; Blanpain, Annick; Raibaut, Laurent; Desmet, Rémi; Vicogne, Jérôme; Melnyk, Oleg

    2015-02-01

    Small ubiquitin-like modifier (SUMO) post-translational modification (PTM) of proteins has a crucial role in the regulation of important cellular processes. This protocol describes the chemical synthesis of functional SUMO-peptide conjugates. The two crucial stages of this protocol are the solid-phase synthesis of peptide segments derivatized by thioester or bis(2-sulfanylethyl)amido (SEA) latent thioester functionalities and the one-pot assembly of the SUMO-peptide conjugate by a sequential native chemical ligation (NCL)/SEA native peptide ligation reaction sequence. This protocol also enables the isolation of a SUMO SEA latent thioester, which can be attached to a target peptide or protein in a subsequent step. It is compatible with 9-fluorenylmethoxycarbonyl (Fmoc) chemistry, and it gives access to homogeneous, reversible and functional SUMO conjugates that are not easily produced using living systems. The synthesis of SUMO-peptide conjugates on a milligram scale takes 20 working days.

  19. Estudo do comportamento de compostos de PVC com adição de amido Study of the behavior of PVC compounds with added starch

    Directory of Open Access Journals (Sweden)

    Lisandra Abatti

    2011-01-01

    Full Text Available Este trabalho apresenta o estudo do comportamento de compostos de PVC com adição de amido para aplicação especialmente na indústria calçadista. As propriedades mecânicas dos compostos nas proporções de 5, 7,5 e 10% foram estudadas através de ensaios de tração. Também foram verificados os índices de fluidez, alterações de propriedades quando submetidos ao envelhecimento artificial em estufa e natural ao expor às intempéries e enterrar no solo. A viabilidade da aplicação na indústria calçadista foi feita por injeção em gáspeas e tiras de sandálias, com testes de resistência, flexão e testes de campo. Os resultados demonstraram que o acréscimo de amido ao PVC provoca perda nas propriedades mecânicas, justificado pela baixa resistência mecânica do amido em relação ao PVC. Após envelhecimento em estufa o processo de retrogradação do amido deixa os compostos mais rígidos e com menor fluidez. Quando expostos às intempéries e ao solo, o PVC pode ser degradado com perda de HCl, o que leva à acidificação do solo. Nas aplicações em calçados e sandálias a resistência mecânica não atende aos requisitos do mercado. Apesar do baixo custo, o fraco comportamento mecânico dificulta sua viabilização para substituição em escala.This paper deals with the behavior of PVC compounds with addition of starch for applications, especially in the footwear industry. The mechanical properties of the compounds in the proportions of 5, 7.5 and 10% were studied using tensile tests. Also investigated were the flow rates, in addition to changes in properties when the material was subjected to artificial aging in an oven and exposed to natural weather and buried in the soil. The feasibility of application in the industry was evaluated with tests of endurance, strength and field tests in injection uppers and straps of sandals. The results showed that the addition of starch to PVC causes loss of mechanical properties, owing to

  20. Preparation of poly(ethylene glycol)-modified poly(amido amine) dendrimers encapsulating gold nanoparticles and their heat-generating ability.

    Science.gov (United States)

    Haba, Yasuhiro; Kojima, Chie; Harada, Atsushi; Ura, Tomoaki; Horinaka, Hiromichi; Kono, Kenji

    2007-05-01

    Loading of HAuCl4 in poly(amido amine) G4 dendrimers having poly(ethylene glycol) (PEG) grafts at all chain ends and subsequent reduction with NaBH4 yielded PEG-modified dendrimers encapsulating gold nanoparticles (Au NPs) of ca. 2 nm diameter. The Au NPs held in the dendrimers were stable in aqueous solutions and dissolved readily, even after freeze-drying. Despite their small particle size, the heat-generating ability of Au NPs held in the dendrimer was comparable to that of widely used Au NPs with ca. 11 nm diameter under visible light irradiation. The observed excellent colloidal stability, high heat-generating ability and their biocompatible surface confirm that the PEG-modified dendrimers encapsulating Au NPs are a promising tool for photothermal therapy and imaging.

  1. Adição de inulina em géis de amido e leite utilizando planejamento experimental de misturas Addition of inulin to starch and milk gels using an experimental mixture design

    Directory of Open Access Journals (Sweden)

    Luciana Pereira Lobato

    2012-06-01

    Full Text Available O objetivo deste estudo foi investigar o efeito combinado de inulina, amido e leite nas características texturais de géis e de propriedades de pastas empregando o planejamento experimental de misturas. Foram avaliados o perfil viscoamilográfico e a firmeza dos géis. Em todos os parâmetros avaliados, os modelos ajustados mostraram-se influenciados pela presença de inulina, amido e leite, assim como de algumas interações desses ingredientes. A viscosidade máxima e a viscosidade final foram influenciadas positivamente pela concentração de amido e negativamente pelas interações deste com leite e com inulina. A firmeza dos géis aumentou com o aumento do teor de amido, mas a interação amido-inulina foi antagônica, contribuindo para diminuir essa característica. O efeito da interação entre amido e inulina pode ser explicado pelo fato de que a inulina possui maior afinidade pela água, em relação ao amido, ou, ainda, por agir como diluente, fazendo com que haja menor contato entre os grânulos e/ou cadeias de amido. A partir dos resultados encontrados neste estudo, verifica-se que a inclusão da inulina em sistemas amido-leite pode influenciar nas características texturais e de viscosidade, possivelmente refletindo-se nas características sensoriais. Com isso, a avaliação das interações com outros ingredientes da formulação torna-se essencial.The objective of this work was to investigate the combined effect of milk, starch and inulin on the textural characteristics of gels and on the pasting properties, using an experimental mixture design. Gel firmness and the amylographic profile were evaluated. For all the parameters evaluated, the fitted models were shown to be influenced by the presence of inulin, starch and milk, as also some of the interactions between the ingredients. The maximum viscosity and final viscosity were positively influenced by the starch concentration and negatively by interactions between the starch and

  2. Características estruturais e físico-químicas de amidos de mandioquinha-salsa (Arracacia xanthorrhiza Structural and physicochemical characteristics of Peruvian carrot (Arracacia xanthorrhiza starch

    Directory of Open Access Journals (Sweden)

    Thaís Souza Rocha

    2008-09-01

    Full Text Available O amido apresenta propriedades físico-químicas importantes que são dependentes de sua fonte botânica e de suas características estruturais. O amido de mandioquinha-salsa possui características especiais que o tornam elegível para utilização em vários alimentos processados. Neste trabalho, amidos de duas variedades de mandioquinha-salsa, Amarela de Carandaí (AC e Amarela de Senador Amaral (ASA, foram isolados e suas características físico-químicas e estruturais determinadas. O amido obtido da variedade ASA apresentou grânulos com diâmetro médio maior que aqueles da variedade AC e mais que o dobro da quantidade de grânulos com tamanho >20 µm, quando comparado à outra variedade. Os amidos de ambas as variedades, observados em microscópio eletrônico de varredura, mostraram superfícies granulares lisas com formatos circulares e poliédricos para grânulos grandes e pequenos, respectivamente. A distribuição de tamanho molecular, viscosidade intrínseca e índice de cristalinidade dos amidos de ambas as variedades foram semelhantes, porém o teor de amilose foi maior para o amido da variedade AC. Maiores valores de viscosidade, poder de inchamento, e temperaturas de gelatinização foram observados para o amido da variedade ASA e podem estar relacionados ao menor teor de amilose e à maior proporção de grânulos grandes apresentados por este amido.Starch has very important physicochemical properties that depend on its botanical source and structural characteristics. Peruvian carrot starch displays special characteristics, which make it appropriate for industrial application in many processed foods. In this work, starch from two Peruvian carrot varieties, Amarela de Carandaí (AC and Amarela de Senador Amaral (ASA, were isolated and their physicochemical and structural properties were determined. Starch from the ASA variety exhibited granules with a greater average diameter than those from the AC variety and more than double

  3. Características físico-químicas e utilização em alimentos de amidos modificados por tratamento oxidativo Obtention, physicochemical characterization and applications in foods of starches modified by oxidative treatment

    Directory of Open Access Journals (Sweden)

    Marianne Ayumi Shirai

    2007-06-01

    Full Text Available A utilização de amidos modificados em alimentos tem sido uma alternativa para melhorar as características que os amidos nativos não podem conferir. Os objetivos deste trabalho foram: avaliar características físico-químicas de amidos modificados com peróxido de hidrogênio, utilizar os amidos obtidos para a elaboração de doce de leite e bala de goma americana e verificar a aceitação sensorial destes produtos. Para obtenção das amostras modificadas, os amidos foram suspensos em solução de Fe2SO4.7H2O 0,01% e, em seguida, adicionou-se peróxido de hidrogênio 1,25%, ajustou-se o pH para 3,0, deixou-se reagir a 45 °C/15 minutos, lavou-se e secou-se a amostra em estufa de ventilação forçada a 45 °C/24 horas. Os amidos modificados apresentaram maior expansão, conteúdo de carboxilas, poder redutor e susceptibilidade à sinérese. Em relação à viscosidade aparente, verificou-se que com a modificação química houve diminuição no pico de viscosidade, especialmente quando as amostras foram analisadas em pH 7,0. A análise sensorial do doce de leite revelou que houve preferência pelas amostras elaboradas com amido de mandioquinha-salsa modificado e com o amido de milho regular ácido-modificado. A bala de goma produzida com amido de mandioquinha-salsa modificado ocupou o segundo lugar entre a preferência dos julgadores.The use of modified starches in foods is made to improve characteristics that the native cannot confer. The objective of this work was to evaluate physicochemical characteristics of starches from several botanical sources after chemical modification with H2O2 considering technological properties of interest to the food industry. The modified starches were used in dulce de leche and starch gum and the sensorial acceptance of these products was verified. The chemical treatment included the suspension of the native starches in a 0.01% Fe2SO4, followed by addition of 1.25% H2O2 at pH 3.0 and reaction time of 15 min

  4. Monomeric adiponectin increases cell viability in porcine aortic endothelial cells cultured in normal and high glucose conditions: Data on kinases activation

    Directory of Open Access Journals (Sweden)

    Elena Grossini

    2016-09-01

    Full Text Available We found that monomeric adiponectin was able to increase cell viability in porcine aortic endothelial cells (PAE cultured both in normal and high glucose condition. Moreover, in normal glucose condition monomeric adiponectin increased p38MAPK, Akt, ERK1/2 and eNOS phosphorylation in a dose- and time-dependent way. Also in high glucose condition monomeric adiponectin increased eNOS and above kinases phosphorylation with similar patterns but at lower extent. For interpretation of the data presented in this article, please see the research article “Monomeric adiponectin modulates nitric oxide release and calcium movements in porcine aortic endothelial cells in normal/high glucose conditions” (Grossini et al., in press [1].

  5. A monomeric methyl and hydroxypropyl methacrylate injection medium and its utility in casting blood capillaries and liver bile canaliculi for scanning electron microscopy.

    Science.gov (United States)

    Murakami, T; Itoshima, T; Hitomi, K; Ohtsuka, A; Jones, A L

    1984-06-01

    A mixture of 50-60% monomeric methyl methacrylate and 40-50% monomeric 2-hydroxypropyl methacrylate was supplemented with 1.5% benzoyl peroxide (catalyst) and 1.5% N,N-dimethylaniline (accelerator) and injected into glutaraldehyde-perfusion fixed rat hypophyseal and other endocrine organ blood vessels and biliary tracts. This injection medium rapidly polymerized at room temperature and did not require partial polymerization prior to injection. Good casts of blood vessels, including the hypophyseal capillaries, were obtained for scanning electron microscopy. The monomeric methacrylate medium possesses a great advantage over previous ones, as its fluidity enables the casting of very fine vessels such as bile canaliculi. In the case of non-fixed tissues, the monomeric methacrylate medium should be injected carefully, as it is toxic and destructive to the vessels.

  6. Caracterização físico-química, reológica, morfológica e térmica dos amidos de milho normal, ceroso e com alto teor de amilose Physicochemical, rheological, morphological, and thermal characterization of normal, waxy, and high amylose corn starches

    OpenAIRE

    Fernanda Hart Weber; Fernanda Paula Collares-Queiroz; Yoon Kil Chang

    2009-01-01

    O objetivo do presente estudo foi avaliar os amidos de milho normal, ceroso e com alto teor de amilose, fabricados pela National Starch, por meio da determinação das suas características físico-químicas, morfológicas, térmicas e reológicas. O amido de milho com alto teor de amilose (AM) apresentou teor de amilose igual a 71%, sendo que os valores obtidos para o amido de milho normal (M) e o amido de milho ceroso (AP) foram de 27,8 e 1,8%, respectivamente. Traços de proteína e lipídios foram e...

  7. Single Enzyme Studies Reveal the Existence of Discrete Functional States for Monomeric Enzymes and How They Are “Selected” upon Allosteric Regulation

    DEFF Research Database (Denmark)

    Hatzakis, Nikos S.; Wei, Li; Jørgensen, Sune Klamer

    2012-01-01

    allosteric regulation of monomeric enzymes is poorly understood. Here we monitored for the first time allosteric regulation of enzymatic activity at the single molecule level. We measured single stochastic catalytic turnovers of a monomeric metabolic enzyme (Thermomyces lanuginosus Lipase) while titrating...... its proximity to a lipid membrane that acts as an allosteric effector. The single molecule measurements revealed the existence of discrete binary functional states that could not be identified in macroscopic measurements due to ensemble averaging. The discrete functional states correlate...

  8. Use of the quartz crystal microbalance to determine the monomeric friction coefficient of polyimides

    Science.gov (United States)

    Bechtold, Mary M.

    1995-01-01

    When a thin film of polymer is coated on to a quartz crystal microbalance (QCM), the QCM can be used to detect the rate of increase in weight of the polymer film as the volatile penetrant diffuses into the polymer. From this rate information the diffusion coefficient of the penetrant into the polymer can be computed. Calculations requiring this diffusion coefficient lead to values which approximate the monomeric friction coefficient of the polymer. This project has been concerned with the trial of crystal oscillating circuits suitable for driving polymer coated crystals in an atmosphere of penetrant. For these studies done at room temperature, natural rubber was used as an easily applied polymer that is readily penetrated by toluene vapors, qualities anticipated with polyimides when they are tested at T(g) in the presence of toluene. Three quartz crystal oscillator circuits were tested. The simplest circuit used +/- 5 volt dc and had a transistor to transistor logic (TTL) inverter chip that provides a 180 deg phase shift via a feed back loop. This oscillator circuit was stable but would not drive the crystal when the crystal was coated with polymer and subjected to toluene vapors. Removal of a variable resistor from this circuit increased stability but did not otherwise increase performance. Another driver circuit tested contained a two stage differential input, differential output, wide band video amplifier and also contain a feed back loop. The circuit voltage could not be varied and operated at +/- 5 volts dc; this circuit was also stable but failed to oscillate the polymer coated crystal in an atmosphere saturated with toluene vapors. The third oscillator circuit was of similar construction and relied on the same video amplifier but allowed operation with variable voltage. This circuit would drive the crystal when the crystal was submerged in liquid toluene and when the crystal was coated with polymer and immersed in toluene vapors. The frequency readings

  9. Efeito da concentração de acido, umidade e temperatura na hidrolise de amido de mandioca por extrusão termoplastica visando a produção de alcool

    OpenAIRE

    1989-01-01

    Resumo: Tem-se conhecimento que a produção de álcool a partir de amido de mandioca tornou-se economicamente inviável, devido ao processo requerer um alto consumo de energia e uso de grande quantidade de água e de enzima α-amilase e amiloglicosidase na etapa de gelatinização, liquefação e sacarificação do amido. Entretanto, a extrusão termoplástica é considerada uma tecnologia que permite a gelatinização e dextrinização de materiais amiláceos a seco com baixo consumo de energia. Portanto, o ob...

  10. Caracterização de amidos de mandioca nativos e modificados e utilização em produtos panificados Characterization of native and modified cassava starches and their use in baked products

    Directory of Open Access Journals (Sweden)

    Krischina Singer Aplevicz

    2007-09-01

    Full Text Available O amido de mandioca é utilizado como ingrediente principal na fabricação de biscoitos e pão de queijo. O polvilho azedo é um produto artesanal, sem padrão de qualidade estabelecido, com problemas de higiene em seu processamento e de oferta. O trabalho teve como objetivo caracterizar amidos de mandioca nativos e modificados e testá-los na elaboração de pão de queijo e biscoito de polvilho. As principais características que diferem o polvilho azedo do amido de mandioca nativo, também denominado polvilho doce são: acidez, grau de expansão, viscosidade, claridade de pasta, sinérese e poder redutor. Foram aplicados nos produtos panificados quatro tipos de amidos, sendo polvilho doce, azedo, amido modificado com peróxido de hidrogênio e amido modificado comercial Expandex® 160003. Obtidos os produtos panificados, foi determinada a composição físico-química e observado que os tipos de amidos influenciaram nas características internas, externas e no sabor. Os produtos panificados foram submetidos à análise sensorial de aceitabilidade, utilizando-se a escala hedônica de nove pontos, com provadores não-treinados. As amostras de pão de queijo contendo amido modificado oxidado com peróxido de hidrogênio foram as que apresentaram o melhor resultado entre as formulações. Para as amostras de biscoito de polvilho, as elaboradas com polvilho azedo e com Expandex® 160003 foram superiores e não diferiram estatisticamente.Cassava starch is used as the main ingredient in the production of biscuits and Brazilian cheese bread. The processing and sale of sour cassava starch - an artisanal product with no established standard of quality - is marked by hygiene problems and its commercial availability is uncertain. The purpose of this study was to characterize native and modified cassava starches and test them in cheese bread and cassava starch biscuit recipes. The main characteristics that differentiate sour starch from native cassava

  11. Caracterização físico-química do grândulo do amido do feijão caupi Physico-chemical characteristics of the granule of the starch of the cowpea bean

    Directory of Open Access Journals (Sweden)

    S.M. Salgado

    2005-09-01

    Full Text Available O presente trabalho objetivou caracterizar quimica e fisicamente o amido de feijão caupi nos estádios de maturação em que o grão é consumido. Grãos verdes e maduros de feijão caupi (Vigna unguiculata L. Walp foram submetidos à determinação da composição centesimal: proteína por Kjeldahl, lipídio por Soxleth, umidade a 105º, cinzas a 550ºC, fibra alimentar por método gravimétrico-enzimático, carboidratos totais por diferença, amido total, glicídios redutores e não redutores, por óxido-redução em solução de Fehling. O amido isolado das distintas amostras foi analisado quanto ao amido resistente (baseado no uso de enzimas amilolíticas, amilose e amilopectina (por espectrofotometria e tipificação (difração de raio-X. Os dados paramétricos foram avaliados pelo teste t de Student. Os resultados obtidos demonstraram que as frações de carboidratos diferiram em função do estádio de maturação dos grãos. O amido de feijão verde apresentou maior teor de amido resistente (AR tipo 2 em relação ao amido total e baixo conteúdo de amilose. A maturação influenciou nos padrões de cristalinidade, sendo encontrado padrão tipo C para o feijão verde e o A para o maduro. O estádio de maturação exerceu influência sobre aspectos qualitativos e quantitativos dos constituintes dos feijões. O aspecto morfológico dos grânulos de amido não sofreu influência do estádio de maturação dos grãos. O feijão verde apresenta um percentual da fibra alimentar solúvel compatível com a recomendação do FDA.This work aimed at characterizing the starch of the cowpea bean in the stages of maturation in which it is consumed both chemically and physically. The unripe and ripe grains of the cowpea bean (Vigna unguiculata L. Walp were submitted to determine the centesimal composition: protein by Kjeldahl, lipids by Soxleth, moisture at 105°C, ashes at 550°C, alimentary fiber by gravimetric-enzymatic method, total carbohydrates

  12. Características físico-químicas de amidos modificados de grau alimentício comercializados no Brasil Physicochemical characteristics of modified food starches commercialized in Brazil

    Directory of Open Access Journals (Sweden)

    Graziela de Oliveira da Silva

    2006-03-01

    Full Text Available Amidos nativos e modificados têm grande importância na indústria de alimentos, sendo empregados principalmente como espessantes e/ou estabilizantes. As limitações das pastas e géis obtidos a partir de amidos nativos tornaram necessário o desenvolvimento de muitos tipos de amidos modificados para aplicações alimentícias. Neste trabalho, algumas amostras de amidos modificados (n=20 disponíveis no Brasil foram recebidas de empresas produtoras e analisadas em relação a algumas características físico-químicas e propriedades tecnológicas. Um levantamento do uso de amidos modificados em alimentos também é apresentado, revelando crescente interesse pela indústria nesses ingredientes. Constatou-se que, enquanto alguns alimentos industrializados, como maioneses contêm em suas formulações amidos modificados, outros como condimento preparado de mostarda contêm apenas amido nativo. As análises físico-químicas permitiram concluir que alguns amidos modificados apresentavam teores elevados de acidez, relacionados à presença de reagentes utilizados em sua obtenção, não havendo presença de carboxilas nas suas macromoléculas. De maneira geral, os resultados de algumas propriedades tecnológicas avaliadas, tais como viscosidade aparente das pastas, resistência a congelamento/descongelamento e propriedade de expansão, estavam de acordo com a descrição dos produtos. As fontes mais observadas nas modificações foram, em ordem decrescente de importância, a mandioca, o milho ceroso e o milho regular.Native and modified starches are very valued for the food industry, being employed mainly as thickeners or stabilizers. Several technological limitations of native starch pastes or gels made it necessary to develop modified starches for the food industry. In the present work modified starch samples (n=20 available in Brazil were received from some producers and evaluated in relation to selected physicochemical characteristics and

  13. Structure/function analysis of PARP-1 in oxidative and nitrosative stress-induced monomeric ADPR formation.

    Directory of Open Access Journals (Sweden)

    Ben Buelow

    Full Text Available Poly adenosine diphosphate-ribose polymerase-1 (PARP-1 is a multifunctional enzyme that is involved in two major cellular responses to oxidative and nitrosative (O/N stress: detection and response to DNA damage via formation of protein-bound poly adenosine diphosphate-ribose (PAR, and formation of the soluble 2(nd messenger monomeric adenosine diphosphate-ribose (mADPR. Previous studies have delineated specific roles for several of PARP-1's structural domains in the context of its involvement in a DNA damage response. However, little is known about the relationship between the mechanisms through which PARP-1 participates in DNA damage detection/response and those involved in the generation of monomeric ADPR. To better understand the relationship between these events, we undertook a structure/function analysis of PARP-1 via reconstitution of PARP-1 deficient DT40 cells with PARP-1 variants deficient in catalysis, DNA binding, auto-PARylation, and PARP-1's BRCT protein interaction domain. Analysis of responses of the respective reconstituted cells to a model O/N stressor indicated that PARP-1 catalytic activity, DNA binding, and auto-PARylation are required for PARP-dependent mADPR formation, but that BRCT-mediated interactions are dispensable. As the BRCT domain is required for PARP-dependent recruitment of XRCC1 to sites of DNA damage, these results suggest that DNA repair and monomeric ADPR 2(nd messenger generation are parallel mechanisms through which PARP-1 modulates cellular responses to O/N stress.

  14. Monomeric Cu(Ⅱ) Complex Containing Chiral Phase-transfer Catalyst as Ligand and Its Asymmetrically Catalytic Reaction

    Institute of Scientific and Technical Information of China (English)

    QU Zhi-Rong; XIONG Ren-Gen

    2008-01-01

    The thermal treatment of CuCl2 with N-(4'-vinylbenzyl)cinchonidinitim chloride(L1)afforded a monomeric discrete homochiral copper(Ⅱ)complex N-4'-(vinylbenzyl)cinchonidinium trichlorocoprate(Ⅱ)(1).Their applications to the enantioselectively catalytic alkylation reaction of N-(diphenylmethylidene)glycine tert-butyl ester(3)show that the higher ee value observed in catalyst 1 than that in the corresponding free ligand L1 is probably due to the rigidity enhancement after the coordination of N atom of quinoline ring to the copper ion.

  15. Two-dimensional crystallization of monomeric bovine cytochrome c oxidase with bound cytochrome c in reconstituted lipid membranes.

    Science.gov (United States)

    Osuda, Yukiho; Shinzawa-Itoh, Kyoko; Tani, Kazutoshi; Maeda, Shintaro; Yoshikawa, Shinya; Tsukihara, Tomitake; Gerle, Christoph

    2016-06-01

    Mitochondrial cytochrome c oxidase utilizes electrons provided by cytochrome c for the active vectorial transport of protons across the inner mitochondrial membrane through the reduction of molecular oxygen to water. Direct structural evidence on the transient cytochrome c oxidase-cytochrome c complex thus far, however, remains elusive and its physiological relevant oligomeric form is unclear. Here, we report on the 2D crystallization of monomeric bovine cytochrome c oxidase with tightly bound cytochrome c at a molar ratio of 1:1 in reconstituted lipid membranes at the basic pH of 8.5 and low ionic strength.

  16. Características físicas de filmes biodegradáveis produzidos a partir de amidos modificados de mandioca Physical characteristics of cassava modified starch films

    Directory of Open Access Journals (Sweden)

    Celina Maria Henrique

    2008-03-01

    Full Text Available Amidos de mandioca podem ser matérias-primas para a obtenção de filmes biodegradáveis, sendo que para a formação destes é necessária a elaboração de suspensões filmogênicas. Alguns processos de modificação do amido podem torná-lo miscível em água fria, e outros processos de modificação podem alterar as propriedades dos filmes, tornando-os mais fortes e flexíveis. O objetivo deste trabalho foi verificar as características físicas de filmes biodegradáveis elaborados com amidos modificados de mandioca pelo processo de casting (desidratação de uma solução filmogênica sobre placas de Petri. Os amidos modificados utilizados foram: cross linked; carboximetilamido (CMA de baixa viscosidade e alta viscosidade e esterificado. A viscosidade é fator importante para a elaboração da suspensão filmogênica e foi avaliada utilizando-se o equipamento Rapid Visco Analyser (RVA. Os filmes elaborados foram comparados a um filme de PVC comercial com espessura de 0,0208 a 0,0217 mm. Os amidos foram caracterizados por avaliação da composição físico-química, granulometria, microscopia eletrônica e viscosidade (Rapid Visco Analyser. A análise por microscopia eletrônica dos filmes ressaltou as diferenças entre os diferentes amidos utilizados. O RVA mostrou que, com exceção do cross linked, todos os amidos modificados apresentaram certa solubilidade a frio, o que facilita o preparo das soluções filmogênicas, entretanto, todos os amidos modificados apresentaram redução acentuada da tendência à retrogradação, propriedade geralmente associada à formação de filmes. As espessuras dos filmes de amido variaram de 0,0551 a 0,1279 mm, cujas espessuras mínimas foram a dos filmes de amido cross linked. Os filmes mostraram-se transparentes, manuseáveis e bem homogêneos. Não houve interferência da espessura na permeabilidade ao vapor d'água, e os filmes com 5% de matéria-seca, independente do tipo de amido modificado

  17. Water barrier properties of starch-clay nanocomposite films Propriedades de barreira à água de filmes de nanocompósitos de amido e argila

    Directory of Open Access Journals (Sweden)

    Aníbal Marcelo Slavutsky

    2012-09-01

    Full Text Available The functional properties of corn starch based films were improved by incorporating nanoclay (Montmorillonite. Nanoclay was incorporated in the polymer matrix using two different methodologies and the films were formed by casting. The effect of film preparation methodology and of the nanoclay concentration on the physicochemical properties of the films was studied. Depending on film preparation method used, intercalated or exfoliated nanocomposite films were obtained. The FTIR spectra showed a strong interaction between the montmorillonite and the starch molecules. Opacity was dependent on the nanoclay dispersion method used. Water vapor solubility and permeability decreased with increasing montmorillonite content and were affected by the dispersion method. Water diffusion was only dependent on the nanoclay content due to the increase in tortuosity of the diffusion path, caused by the nanoparticles. The results showed that the incorporation of 5% of montmorillonite using an adequate dispersion method, improved the water resistance and barrier properties of corn starch based films. Nanoparticles reduced the damage caused to the properties of these hydrophilic films by the increase in moisture content.As propriedades funcionais de filmes à base de amido de milho foram melhoradas pela incorporação de nanoargila (montmorilonita. Nanoargila foi incorporada na matriz polimérica por meio de duas metodologias diferentes e os filmes foram produzidos por casting. Os efeitos da metodologia de preparação e da concentração de nanoargila nas propriedades físico-químicas dos filmes foram estudados. Conforme os métodos de elaboração, filmes intercalados e esfoliados de nanocompósitos foram obtidos. Os espectros FTIR mostraram uma forte interação entre a argila montmorilonita e as moléculas de amido. A opacidade foi dependente do método utilizado para a dispersão da nanoargila. A solubilidade e a permeabilidade ao vapor de água diminu

  18. Influência de hidrocolóides na textura de gel de amido de milho Influence of hydrocolloids in texture of corn starch gel

    Directory of Open Access Journals (Sweden)

    Maisa Peixoto Munhoz

    2004-09-01

    Full Text Available O presente trabalho tem como objetivo determinar a influência das interações das gomas xantana e guar com o amido de milho de alto teor de amilose na textura de gel durante o armazenamento. Foram utilizadas amostras de amido milho Hylon VII® (71% de amilose, National Starch, goma guar (Higum 55I®, Rhodia e goma xantana (Rhodigel 200®, Rhodia. Foram utilizadas diferentes concentrações das gomas guar e xantana, que variaram de 0 a 1%, de acordo com o delineamento experimental central composto rotacional. Em cada tratamento foram utilizadas 50g de amido com alto teor de amilose (Hylon VII, adicionadas das gomas. Estas amostras foram diluídas em água destilada e submetidas à agitação mecânica até completa dissolução. As soluções foram aquecidas até 95°C por 5 minutos para formação dos géis, os quais foram acondicionados em recipientes plásticos de 50mL e mantidos em temperatura de 5-10°C até 120h. Nos tempos T1 (24h, T2 (48h, T3 (72h, T4 (96h e T5 (120h de armazenamento foram feitas medidas da força máxima do gel de amilose em texturômetro (Stable Micro-System, Modelo TAX-T2. No período inicial, de 24 horas, a goma guar não apresentou influência positiva na redução da força do gel, sendo que a aplicação de goma xantana entre 0,7 e 1,0% apresentou os menores valores de força do gel de amilose. Após 120h de armazenamento, a força do gel de amilose diminuiu com a adição de 0,5-1,0% de goma xantana e 0-0,15% de goma guar.The main objective of this study was to determine the influence of the interactions between guar and xanthan gums with high amylose content corn starch on the texture of the gel during storage. The samples used were Hylon VII® corn starch (71% amylose (National Starch, Guar gum (Higum 551®, Rhodia and Xanthan gum (Rhodigel 200®, Rhodia. A central composite rotational design was used to formulate gels with different concentrations of the guar and xanthan gums, from 0 to 1%. For each treatment

  19. Caracterização físico-química, reológica, morfológica e térmica dos amidos de milho normal, ceroso e com alto teor de amilose Physicochemical, rheological, morphological, and thermal characterization of normal, waxy, and high amylose corn starches

    Directory of Open Access Journals (Sweden)

    Fernanda Hart Weber

    2009-12-01

    Full Text Available O objetivo do presente estudo foi avaliar os amidos de milho normal, ceroso e com alto teor de amilose, fabricados pela National Starch, por meio da determinação das suas características físico-químicas, morfológicas, térmicas e reológicas. O amido de milho com alto teor de amilose (AM apresentou teor de amilose igual a 71%, sendo que os valores obtidos para o amido de milho normal (M e o amido de milho ceroso (AP foram de 27,8 e 1,8%, respectivamente. Traços de proteína e lipídios foram encontrados nas amostras. O amido de milho ceroso apresentou maior viscosidade máxima e uma menor tendência à retrogradação, se comparado ao amido de milho normal. O amido AP apresentou menor entalpia de gelatinização, como pode ser observado nas análises de calorimetria exploratória diferencial (DSC, na qual a temperatura de gelatinização foi de 75 °C e o ΔH de 3,34 J.g-1, e também na análise de RVA (Rapid Visco Analyser, em que a temperatura de pasta foi de 71 °C. Apresentando, dessa forma, valores inferiores aos verificados para os outros amidos. O valor do ΔH de retrogradação do amido AP, mostrou-se 25,8% inferior ao ΔH do amido M. O amido AM apresentou o valor de 26,38 J.g-1, demonstrando o maior envolvimento da molécula de amilose no processo de retrogradação. Isso também foi evidenciado pela medida da força dos géis: o gel de AM apresentou força 99,18% superior, retrogradando mais que os outros amidos. As análises de difração de raio X mostraram que os amidos de milho normal e ceroso apresentaram um padrão de difração do tipo A e o amido de milho com alto teor de amilose apresentou padrão do tipo B.The objective of this work was to evaluate normal, waxy, and high amylose corn starches from National Starch, through the determination of the physicochemical, morphological, thermal, and rheological properties. The high amylose corn starch (AM presented amylose content of 71%, and the value of this component for the

  20. Conditions for homogeneous preparation of stable monomeric and oligomeric forms of activated Vip3A toxin from Bacillus thuringiensis.

    Science.gov (United States)

    Kunthic, Thittaya; Surya, Wahyu; Promdonkoy, Boonhiang; Torres, Jaume; Boonserm, Panadda

    2016-07-29

    Bacillus thuringiensis vegetative insecticidal proteins like Vip3A have been used for crop protection and to delay resistance to existing insecticidal Cry toxins. However, little is known about Vip3A's behavior or its mechanism of action, and a structural model is required. Herein, in an effort to facilitate future crystallization and functional studies, we have used the orthogonal biophysical techniques of light scattering and sedimentation to analyze the aggregation behavior and stability of trypsin-activated Vip3A toxin in solution. Both scattering and sedimentation data suggest that at pH 10 the toxin is monomeric and adopts an elongated shape, but after overnight incubation aggregation was observed at all pH values tested (5-12). The narrowest size distribution was observed at pH 7, but it was consistent with large oligomers of ~50 nm on average. The addition of β-D-glucopyranoside (OG) helped in achieving preparations that were stable and with a narrower particle size distribution. In this case, scattering was consistent with a 4-nm monomeric globular Vip3A form. After OG dialysis, 40-nm particles were detected, with a molecular weight consistent with homotetramers. Therefore, OG is proposed as the detergent of choice to obtain a Vip3A crystal for structural studies, either before (monomers) or after dialysis (tetramers).

  1. Structural analysis of the bright monomeric yellow-green fluorescent protein mNeonGreen obtained by directed evolution.

    Science.gov (United States)

    Clavel, Damien; Gotthard, Guillaume; von Stetten, David; De Sanctis, Daniele; Pasquier, Hélène; Lambert, Gerard G; Shaner, Nathan C; Royant, Antoine

    2016-12-01

    Until recently, genes coding for homologues of the autofluorescent protein GFP had only been identified in marine organisms from the phyla Cnidaria and Arthropoda. New fluorescent-protein genes have now been found in the phylum Chordata, coding for particularly bright oligomeric fluorescent proteins such as the tetrameric yellow fluorescent protein lanYFP from Branchiostoma lanceolatum. A successful monomerization attempt led to the development of the bright yellow-green fluorescent protein mNeonGreen. The structures of lanYFP and mNeonGreen have been determined and compared in order to rationalize the directed evolution process leading from a bright, tetrameric to a still bright, monomeric fluorescent protein. An unusual discolouration of crystals of mNeonGreen was observed after X-ray data collection, which was investigated using a combination of X-ray crystallography and UV-visible absorption and Raman spectroscopies, revealing the effects of specific radiation damage in the chromophore cavity. It is shown that X-rays rapidly lead to the protonation of the phenolate O atom of the chromophore and to the loss of its planarity at the methylene bridge.

  2. Processing and storage effects on monomeric anthocyanins, percent polymeric color, and antioxidant capacity of processed blueberry products.

    Science.gov (United States)

    Brownmiller, C; Howard, L R; Prior, R L

    2008-06-01

    This study evaluated the effects of processing and 6 mo of storage on total monomeric anthocyanins, percent polymeric color, and antioxidant capacity of blueberries that were canned in syrup (CS), canned in water (CW), pureed, and juiced (clarified and nonclarified). Total monomeric anthocyanins, percent polymeric color, and oxygen radical absorbing capacity (ORAC) assay using fluorescein (ORAC(FL)) were determined postprocessing after 1 d, and 1, 3, and 6 mo of storage. Thermal processing resulted in marked losses in total anthocyanins (28% to 59%) and ORAC(FL) values (43% to 71%) in all products, with the greatest losses occurring in clarified juices and the least in nonclarified juices. Storage at 25 degrees C for 6 mo resulted in dramatic losses in total anthocyanins, ranging from 62% in berries CW to 85% in clarified juices. This coincided with marked increases in percent polymeric color values of these products over the 6-mo storage. The ORAC(FL) values showed little change during storage, indicating that the formation of polymers compensated for the loss of antioxidant capacity due to anthocyanin degradation. Methods are needed to retain anthocyanins in thermally processed blueberries.

  3. Processing and storage effects on monomeric anthocyanins, percent polymeric color, and antioxidant capacity of processed black raspberry products.

    Science.gov (United States)

    Hager, A; Howard, L R; Prior, R L; Brownmiller, C

    2008-08-01

    This study evaluated the effects of processing and 6 mo of storage on total monomeric anthocyanins, percent polymeric color, and antioxidant capacity of black raspberries that were individually quick-frozen (IQF), canned-in-syrup, canned-in-water, pureed, and juiced (clarified and nonclarified). Total monomeric anthocyanins, percent polymeric color, and ORAC(FL) were determined 1 d postprocessing and after 1, 3, and 6 mo of storage. Thermal processing resulted in marked losses in total anthocyanins ranging from 37% in puree to 69% to 73% in nonclarified and clarified juices, respectively, but only the juices showed substantial losses (38% to 41%) in ORAC(FL). Storage at 25 degrees C of all thermally processed products resulted in dramatic losses in total anthocyanins ranging from 49% in canned-in-syrup to 75% in clarified juices. This coincided with marked increases in percent polymeric color values of these products over the 6-mo storage. ORAC(FL) values showed little change during storage, indicating that the formation of polymers compensated for the loss of antioxidant capacity due to anthocyanin degradation. Total anthocyanins and ORACFL of IQF berries were well retained during long-term storage at -20 degrees C.

  4. Interaction of Classical Platinum Agents with the Monomeric and Dimeric Atox1 Proteins: A Molecular Dynamics Simulation Study

    Directory of Open Access Journals (Sweden)

    Xiaolei Wang

    2013-12-01

    Full Text Available We carried out molecular dynamics simulations and free energy calculations for a series of binary and ternary models of the cisplatin, transplatin and oxaliplatin agents binding to a monomeric Atox1 protein and a dimeric Atox1 protein to investigate their interaction mechanisms. All three platinum agents could respectively combine with the monomeric Atox1 protein and the dimeric Atox1 protein to form a stable binary and ternary complex due to the covalent interaction of the platinum center with the Atox1 protein. The results suggested that the extra interaction from the oxaliplatin ligand–Atox1 protein interface increases its affinity only for the OxaliPt + Atox1 model. The binding of the oxaliplatin agent to the Atox1 protein might cause larger deformation of the protein than those of the cisplatin and transplatin agents due to the larger size of the oxaliplatin ligand. However, the extra interactions to facilitate the stabilities of the ternary CisPt + 2Atox1 and OxaliPt + 2Atox1 models come from the α1 helices and α2-β4 loops of the Atox1 protein–Atox1 protein interface due to the cis conformation of the platinum agents. The combinations of two Atox1 proteins in an asymmetric way in the three ternary models were analyzed. These investigations might provide detailed information for understanding the interaction mechanism of the platinum agents binding to the Atox1 protein in the cytoplasm.

  5. Combinações de fontes de nitrogênio e amido de alta e baixa degradabilidade ruminal avaliadas pela técnica in situ Combinations of starch and nitrogen sources in high and low ruminal degradability evaluated by in situ technique

    Directory of Open Access Journals (Sweden)

    Ivanor Nunes do Prado

    1998-10-01

    Full Text Available Este trabalho teve por objetivo avaliar a degradabilidade ruminal de quatro concentrados, os quais diferiam entre si pela diferença na degradação ruminal das fontes de amido e nitrogênio utilizadas. Foram utilizadas três vacas da raça Holandesa, com peso médio de 530kg e portadoras de cânula ruminal. Os concentrados formulados com fonte de amido e nitrogênio de alta degradabilidade ruminal apresentaram maiores valores de degradabilidade efetiva (DE da matéria seca, proteína bruta e amido para taxas de passagem de 2%/h, 5%/h e 8%/h e o inverso foi observado para os concentrados com fontes de amido e nitrogênio de baixa degradabilidade ruminal. Os concentrados formulados alternando as fontes de amido e de nitrogênio de alta e baixa degradabilidade ruminal apresentaram valores intermediários de DE da matéria seca e da proteína. A DE do amido foi influenciada pela fonte de amido independentemente da fonte de nitrogênio.The objective of this paper was to evaluate the ruminal degradability of four isonitrogenized and isoenergetic concentrates which differed as for starch and nitrogen sources. Three holstein cows with 530kg average weight and fistulated rumen were used in this investigation. The concentrates formulated with starch and nitrogen sources of high ruminal degradability presented higher values of drymatter, crude protein and starch effective degradability (ED for 2%/h, 5%/h and 8%/h passage rates, but the reverse was also observed for concentrates with starch and nitrogen sources of low ruminal degradability. The concentrates formulated by alternating starch and nitrogen sources of high and low ruminal degradability showed dry matter and protein ED intermediate values. The starch ED was influenced by the starch source independently of the nitrogen source.

  6. Oxidação dos amidos de mandioca e de milho comum fermentados: desenvolvimento da propriedade de expansão Oxidation of fermented cassava and corn starches: development of the expansion property

    Directory of Open Access Journals (Sweden)

    Alvaro Renato Guerra Dias

    2007-12-01

    Full Text Available Amidos de mandioca e de milho comum foram fermentados em laboratório a 20 °C, sendo uma fração seca ao sol e outra oxidada com peróxido de hidrogênio e secada artificialmente, visando o desenvolvimento da propriedade de expansão. Estudou-se a fermentação em 0, 10, 30 e 50 dias, sendo a propriedade de expansão no forneamento avaliada pelo teste do biscoito e o comportamento viscoamilográfico pelo RVA. Verificou-se que a fermentação promove modificação que auxilia na oxidação dos amidos de mandioca e de milho elevando a acidez titulável do produto. O amido de mandioca fermentado oxidado com exposição solar ou com peróxido de hidrogênio pode desenvolver a propriedade de expansão, já o amido de milho comum nessas condições não tem essa capacidade. Os melhores resultados para a propriedade de expansão foram no amido de mandioca oxidado com peróxido de hidrogênio aos 50 dias de fermentação.Cassava and corn starches were fermented in the laboratory at 20 °C, and a fraction was in the sun while another fraction was oxidized with hydrogen peroxide and dried artificially to develop the expansion property. Fermentation in 0, 10, 30 and 50 days was checked and the expansion property was evaluated by the baking test and viscoamilograph behavior (RVA. Fermentation was found to cause changes that help the oxidation of cassava and corn starches, increasing the product's titrable acidity. The fermented cassava starch, oxidized by exposure to sunlight or hydrogen peroxide, may develop the expansion property, but the corn starch did not display that ability under these conditions. The best results for the expansion property were obtained with cassava starch oxidized with hydrogen peroxide after 50 days of fermentation.

  7. No need to be HAMLET or BAMLET to interact with histones: binding of monomeric alpha-lactalbumin to histones and basic poly-amino acids.

    Science.gov (United States)

    Permyakov, Serge E; Pershikova, Irina V; Khokhlova, Tatyana I; Uversky, Vladimir N; Permyakov, Eugene A

    2004-05-18

    The ability of a specific complex of human alpha-lactalbumin with oleic acid (HAMLET) to induce cell death with selectivity for tumor and undifferentiated cells was shown recently to be mediated by interaction of HAMLET with histone proteins irreversibly disrupting chromatin structure [Duringer, C., et al. (2003) J. Biol. Chem. 278, 42131-42135]. Here we show that monomeric alpha-lactalbumin (alpha-LA) in the absence of fatty acids is also able to bind efficiently to the primary target of HAMLET, histone HIII, regardless of Ca(2+) content. Thus, the modification of alpha-LA by oleic acid is not required for binding to histones. We suggest that interaction of negatively charged alpha-LA with the basic histone stabilizes apo-alpha-LA and destabilizes the Ca(2+)-bound protein due to compensation for excess negative charge of alpha-LA's Ca(2+)-binding loop by positively charged residues of the histone. Spectrofluorimetric curves of titration of alpha-LA by histone H3 were well approximated by a scheme of cooperative binding of four alpha-LA molecules per molecule of histone, with an equilibrium dissociation constant of 1.0 microM. Such a stoichiometry of binding implies that the binding process is not site-specific with respect to histone and likely is driven by just electrostatic interactions. Co-incubation of positively charged poly-amino acids (poly-Lys and poly-Arg) with alpha-LA resulted in effects which were similar to those caused by histone HIII, confirming the electrostatic nature of the alpha-LA-histone interaction. In all cases that were studied, the binding was accompanied by aggregation. The data indicate that alpha-lactalbumin can be used as a basis for the design of antitumor agents, acting through disorganization of chromatin structure due to interaction between alpha-LA and histone proteins.

  8. Spectroscopic Characterization of a Monomeric, Cyclopentadienyl-Based Rhenium(V) Dioxo Complex

    DEFF Research Database (Denmark)

    Raju, Suresh; Jastrzebski, Johann T. B. H.; Lutz, Martin

    2015-01-01

    spectrometry. (Cpttt)ReO2 is shown to be the primary product of reduction of the rhenium(VII) complex (Cpttt)ReO3 with PPh3 and demonstrated to react with ethylene glycol significantly faster than its dimeric counterpart, supporting its role as an intermediate in rhenium-catalyzed deoxydehydration reactions....

  9. ELABORAÇÃO DE SALSICHAS UTILIZANDO GOMA GUAR E GOMA XANTANA EM SUBSTITUIÇÃO AO AMIDO DE MANDIOCA (MANIHOT ESCULENTA

    Directory of Open Access Journals (Sweden)

    Crispin Humberto GARCIA-CRUZ

    2009-07-01

    Full Text Available

    RESUMO: Foram elaboradas salsichas utilizando uma formulação padrão, na qual foi usado amido de mandioca na concentração de 2%, substituindo posteriormente por 1% das gomas guar e xantana. Para estes três tipos de salsichas foram determinadas a estabilidade ao calor, a análise da textura e a análise sensorial. Foram enlatadas e armazenadas por 90 dias à temperatura ambiente. Após este período foi determinada a concentração de gordura liberada na salmoura. Os resultados obtidos foram analisados estatisticamente e foi observado que as salsichas elaboradas com os hidrocolóides acima mencionados apresentaram a mesma estabilidade ao tratamento térmico e não apresentaram diferenças significativas em relação ao painel de provadores. Entretanto, as salsichas enlatadas preparadas com goma xantana retiveram maior quantidade de gordura, proporcionando um produto de melhor aparência. PALAVRAS-CHAVE: Hidrocolóides; elaboração de salsichas; emulsões de carne.

  10. Studies on the Rice LEAF INCLINATION1 (LC1),an IAA-amido Synthetase, Reveal the Effects of Auxin in Leaf Inclination Control

    Institute of Scientific and Technical Information of China (English)

    Shu-Qing Zhao; Jing-Jing Xiang; Hong-Wei Xue

    2013-01-01

    The angle of rice leaf inclination is an important agronomic trait and closely related to the yields and architecture of crops.Although few mutants with altered leaf angles have been reported,the molecular mechanism remains to be elucidated,especially whether hormones are involved in this process.Through genetic screening,a rice gain-offunction mutant leaf inclination1,Ic1-D,was identified from the Shanghai T-DNA Insertion Population (SHIP).Phenotypic analysis confirmed the exaggerated leaf angles of Ic1-D due to the stimulated cell elongation at the lamina joint.LC1 is transcribed in various tissues and encodes OsGH3-1,an indole-3-acetic acid (IAA) amido synthetase,whose homolog of Arabidopsis functions in maintaining the auxin homeostasis by conjugating excess IAA to various amino acids.Indeed,recombinant LC1 can catalyze the conjugation of IAA to Ala,Asp,and Asn in vitro,which is consistent with the decreased free IAA amount in Ic1-D mutant.Ic1-D is insensitive to IAA and hypersensitive to exogenous BR,in agreement with the microarray analysis that reveals the altered transcriptions of genes involved in auxin signaling and BR biosynthesis.These results indicate the crucial roles of auxin homeostasis in the leaf inclination control.

  11. Low-temperature CVD of iron, cobalt, and nickel nitride thin films from bis[di(tert-butyl)amido]metal(II) precursors and ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Cloud, Andrew N.; Abelson, John R., E-mail: abelson@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 201 Materials Science and Engineering Building, 1304 W. Green St., Urbana, Illinois 61801 (United States); Davis, Luke M.; Girolami, Gregory S., E-mail: girolami@scs.illinois.edu [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801 (United States)

    2014-03-15

    Thin films of late transition metal nitrides (where the metal is iron, cobalt, or nickel) are grown by low-pressure metalorganic chemical vapor deposition from bis[di(tert-butyl)amido]metal(II) precursors and ammonia. These metal nitrides are known to have useful mechanical and magnetic properties, but there are few thin film growth techniques to produce them based on a single precursor family. The authors report the deposition of metal nitride thin films below 300 °C from three recently synthesized M[N(t-Bu){sub 2}]{sub 2} precursors, where M = Fe, Co, and Ni, with growth onset as low as room temperature. Metal-rich phases are obtained with constant nitrogen content from growth onset to 200 °C over a range of feedstock partial pressures. Carbon contamination in the films is minimal for iron and cobalt nitride, but similar to the nitrogen concentration for nickel nitride. X-ray photoelectron spectroscopy indicates that the incorporated nitrogen is present as metal nitride, even for films grown at the reaction onset temperature. Deposition rates of up to 18 nm/min are observed. The film morphologies, growth rates, and compositions are consistent with a gas-phase transamination reaction that produces precursor species with high sticking coefficients and low surface mobilities.

  12. Diagnóstico bioquímico de la hiperprolactinemia monomérica Biochemical diagnosis of monomeric hyperprolactinemia

    Directory of Open Access Journals (Sweden)

    A. Rivero

    2011-08-01

    Full Text Available Fundamento. La prolactina se puede presentar bajo varias formas moleculares siendo la forma monomérica (PRLm la biológicamente activa. La presencia de macroprolactina (MPRL puede originar un falso diagnóstico de hiperprolactinemia debido a la interferencia en el procedimiento de medida. El objetivo ha sido desarrollar un protocolo que permita diagnosticar la hiperprolactinemia monomérica, que además sea complementario al procedimiento que detecta MPRL. Material y métodos. La población de referencia para PRLm estaba formada por 122 mujeres y 140 hombres aparentemente sanos a los que se les extrajo sangre para la cuantificación de PRL. Además, se recogieron 49 sueros (33 mujeres y 16 hombres hiperprolactinémicos. Se cuantificó PRL en todas las muestras en un Immulite 2000. La detección de MPRL y de PRLm se realizó tras precipitación con polietilenglicol. Se confirmó el resultado por cromatografía de filtración en gel. Para la obtención de los valores de referencia se siguieron las indicaciones del Panel de Expertos de la IFCC. Resultados. Los valores de referencia de PRLm fueron 3,4-26,6 μg/L y 4,6-16,4 μg/L en mujeres y varones, respectivamente. De los 49 pacientes hiperprolactinémicos, en el 57 % la concentración de PRLm tras PEG se encontraba fuera del intervalo de referencia previamente obtenido, confirmándose la presencia de hiperprolactinemia monomérica. Conclusiones. Se ha desarrollado e implantado un protocolo para la cuantificación de PRLm. La obtención de los valores de referencia de PRLm permite el diagnóstico de la hiperprolactinemia monomérica o activa de forma complementaria a la identificación de MPRL.Background. Prolactin can take several molecular forms of which the most biologically active is the monomeric form (PRLm. The presence of macroprolactin (MPRL can give rise to a false diagnosis of hyperprolactinemia due to interference in the measuring procedure. The aim was to develop a protocol that

  13. A monomeric G protein-coupled receptor isolated in a high-density lipoprotein particle efficiently activates its G protein

    DEFF Research Database (Denmark)

    Whorton, Matthew R; Bokoch, Michael P; Rasmussen, Søren Gøgsig Faarup;

    2007-01-01

    G protein-coupled receptors (GPCRs) respond to a diverse array of ligands, mediating cellular responses to hormones and neurotransmitters, as well as the senses of smell and taste. The structures of the GPCR rhodopsin and several G proteins have been determined by x-ray crystallography, yet...... the organization of the signaling complex between GPCRs and G proteins is poorly understood. The observations that some GPCRs are obligate heterodimers, and that many GPCRs form both homo- and heterodimers, has led to speculation that GPCR dimers may be required for efficient activation of G proteins. However......, technical limitations have precluded a definitive analysis of G protein coupling to monomeric GPCRs in a biochemically defined and membrane-bound system. Here we demonstrate that a prototypical GPCR, the beta2-adrenergic receptor (beta2AR), can be incorporated into a reconstituted high-density lipoprotein...

  14. Synthesis of monomeric and polymeric alkali and alkaline earth metal complexes using a phosphinoselenoic amide ligand in metal coordination sphere

    Indian Academy of Sciences (India)

    Jayeeta Bhattacharjee; Ravi K Kottalanka; Harinath Adimulam; Tarun K Panda

    2014-09-01

    We report the monomeric complexes of magnesium and calcium of composition [M(THF){2-Ph2P(Se)N(CMe3)}2] [M= Mg (3), n = 1 andM = Ca (4), n = 2)] and polymeric complexes of potassium and barium of composition [K(THF)2{Ph2P(Se)N(CMe3)}] (2) and [K(THF)Ba{Ph2P(Se)N(CMe3)}3](5) respectively. The potassium complex 2 was readily prepared by the reaction of potassium bis(trimethylsilyl)amide with phosphinoselenoic amide ligand (1) at ambient temperature. The calcium complex 4 was prepared by two synthetic routes: in the first method, commonly known as salt metathesis reaction, the potassium complex 2 was made to react with alkaline earth metal diiodide at room temperature to afford the corresponding calcium complex. The metal bis(trimethylsilyl)amides were made to react with protic ligand 1 in the second method to eliminate the volatile bis(trimethyl)silyl amine. The magnesium complex 3 and barium complex 5 were prepared only through the first method. Solid-state structures of all the new complexes were established by single crystal X-ray diffraction analysis. The smaller ionic radii of Mg2+ (0.72Å) and Ca2+ (0.99Å) ions form the monomeric complex, whereas the larger ions K+ (1.38Å) and Ba2+ (1.35Å) were found to form onedimensional polymeric complexes with monoanionic ligand 1. Compound 2 serves an example of magnesium complex with a Mg-Se direct bond.

  15. Urea Unfolding Study of E. coli Alanyl-tRNA Synthetase and Its Monomeric Variants Proves the Role of C-Terminal Domain in Stability

    Directory of Open Access Journals (Sweden)

    Baisakhi Banerjee

    2015-01-01

    Full Text Available E. coli alanyl-tRNA exists as a dimer in its native form and the C-terminal coiled-coil part plays an important role in the dimerization process. The truncated N-terminal containing the first 700 amino acids (1–700 forms a monomeric variant possessing similar aminoacylation activity like wild type. A point mutation in the C-terminal domain (G674D also produces a monomeric variant with a fivefold reduced aminoacylation activity compared to the wild type enzyme. Urea induced denaturation of these monomeric mutants along with another alaRS variant (N461 alaRS was studied together with the full-length enzyme using various spectroscopic techniques such as intrinsic tryptophan fluorescence, 1-anilino-8-naphthalene-sulfonic acid binding, near- and far-UV circular dichroism, and analytical ultracentrifugation. Aminoacylation activity assay after refolding from denatured state revealed that the monomeric mutants studied here were unable to regain their activity, whereas the dimeric full-length alaRS gets back similar activity as the native enzyme. This study indicates that dimerization is one of the key regulatory factors that is important in the proper folding and stability of E. coli alaRS.

  16. Crystallization and preliminary crystallographic analysis of decameric and monomeric forms of C49S mutant thioredoxin-dependent AhpC from Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Supangat [Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Seo, Kyung Hye; Furqoni, Ahmad [Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Kwon, Young-Chul; Cho, Myung-Je; Rhee, Kwang-Ho [Department of Microbiology, School of Medicine, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Lee, Sang Yeol; Lee, Kon Ho, E-mail: lkh@gsnu.ac.kr [Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of)

    2008-05-01

    Decameric and monomeric forms of recombinant C49S mutant AhpC from H. pylori have been crystallized. Diffraction data were collected to 2.8 and 2.25 Å, respectively. Cys49Ser mutant Helicobacter pylori alkyl hydroperoxide reductase (C49S HpAhpC) was purified under reducing conditions in monomeric and decameric forms. The monomeric form was crystallized by the hanging-drop vapour-diffusion method. The crystals diffracted to 2.25 Å resolution and belonged to space group C2, with unit-cell parameters a = 245.8, b = 140.7, c = 189.5 Å, β = 127°, and contained 20 molecules in the asymmetric unit. A crystal of the decameric form was obtained by the microbatch crystallization method and diffracted to 2.8 Å resolution. It belonged to space group C222, with unit-cell parameters a = 257.5, b = 417.5, c = 95.6 Å. The structure of the monomeric form of C49S HpAhpC has been solved by the molecular-replacement method.

  17. Urea Unfolding Study of E. coli Alanyl-tRNA Synthetase and Its Monomeric Variants Proves the Role of C-Terminal Domain in Stability

    Science.gov (United States)

    Banerjee, Baisakhi; Banerjee, Rajat

    2015-01-01

    E. coli alanyl-tRNA exists as a dimer in its native form and the C-terminal coiled-coil part plays an important role in the dimerization process. The truncated N-terminal containing the first 700 amino acids (1–700) forms a monomeric variant possessing similar aminoacylation activity like wild type. A point mutation in the C-terminal domain (G674D) also produces a monomeric variant with a fivefold reduced aminoacylation activity compared to the wild type enzyme. Urea induced denaturation of these monomeric mutants along with another alaRS variant (N461 alaRS) was studied together with the full-length enzyme using various spectroscopic techniques such as intrinsic tryptophan fluorescence, 1-anilino-8-naphthalene-sulfonic acid binding, near- and far-UV circular dichroism, and analytical ultracentrifugation. Aminoacylation activity assay after refolding from denatured state revealed that the monomeric mutants studied here were unable to regain their activity, whereas the dimeric full-length alaRS gets back similar activity as the native enzyme. This study indicates that dimerization is one of the key regulatory factors that is important in the proper folding and stability of E. coli alaRS. PMID:26617997

  18. Calcium, acylation, and molecular confinement favor folding of Bordetella pertussis adenylate cyclase CyaA toxin into a monomeric and cytotoxic form.

    Science.gov (United States)

    Karst, Johanna C; Ntsogo Enguéné, V Yvette; Cannella, Sara E; Subrini, Orso; Hessel, Audrey; Debard, Sylvain; Ladant, Daniel; Chenal, Alexandre

    2014-10-31

    The adenylate cyclase (CyaA) toxin, a multidomain protein of 1706 amino acids, is one of the major virulence factors produced by Bordetella pertussis, the causative agent of whooping cough. CyaA is able to invade eukaryotic target cells in which it produces high levels of cAMP, thus altering the cellular physiology. Although CyaA has been extensively studied by various cellular and molecular approaches, the structural and functional states of the toxin remain poorly characterized. Indeed, CyaA is a large protein and exhibits a pronounced hydrophobic character, making it prone to aggregation into multimeric forms. As a result, CyaA has usually been extracted and stored in denaturing conditions. Here, we define the experimental conditions allowing CyaA folding into a monomeric and functional species. We found that CyaA forms mainly multimers when refolded by dialysis, dilution, or buffer exchange. However, a significant fraction of monomeric, folded protein could be obtained by exploiting molecular confinement on size exclusion chromatography. Folding of CyaA into a monomeric form was found to be critically dependent upon the presence of calcium and post-translational acylation of the protein. We further show that the monomeric preparation displayed hemolytic and cytotoxic activities suggesting that the monomer is the genuine, physiologically active form of the toxin. We hypothesize that the structural role of the post-translational acylation in CyaA folding may apply to other RTX toxins.

  19. Analysis of by-product formation and sugar monomerization in sugarcane bagasse pretreated at pilot plant scale: Differences between autohydrolysis, alkaline and acid pretreatment

    NARCIS (Netherlands)

    Pol, van der E.C.; Bakker, R.; Zeeland, van A.N.T.; Sanchez Garcia, D.; Punt, A.M.; Eggink, G.

    2015-01-01

    Sugarcane bagasse is an interesting feedstock for the biobased economy since a large fraction is polymerized sugars. Autohydrolysis, alkaline and acid pretreatment conditions combined with enzyme hydrolysis were used on lignocellulose rich bagasse to acquire monomeric. By-products found after pretre

  20. Desempenho produtivo e atividade microbiana cecal de coelhos alimentados com dietas contendo diferentes níveis de amido Performance and cecal microbial activity of growing rabbits fed diets with different starch levels

    Directory of Open Access Journals (Sweden)

    Alex Martins Varela de Arruda

    2000-06-01

    Full Text Available Com o objetivo de avaliar a influência do amido dietético sobre o rendimento produtivo e a atividade microbiana cecal de coelhos em crescimento, quatro dietas experimentais foram elaboradas de forma a conter níveis crescentes de amido (23, 28, 33 e 38% de amido total na base da MS, os quais foram fornecidos a 32 coelhos da raça Nova Zelândia Branco, distribuídos em gaiolas de engorda individuais, seguindo um delineamento em blocos casualizados. Houve efeito linear decrescente para consumo e conversão alimentar, em que valores de 108,67 g/d e 3,216, respectivamente, foram obtidos para os animais alimentados com 38% de amido dietético. No entanto, o ganho de peso e o rendimento de carcaça não foram influenciados pelos tratamentos. Por outro lado, os valores de pH, as concentrações totais e as proporções molares dos ácidos graxos voláteis não foram influenciados pelos tratamentos, porém, para o ácido propiônico, houve efeito linear decrescente, sendo a maior proporção molar (12,06% verificada no conteúdo cecal de coelhos alimentados com 23% de amido dietético. O milho-grão apresentou maior influência sobre a atividade microbiana cecal que o amido de milho purificado, porém, sem alterar o desempenho e rendimento de carcaça.With the objective to evaluate the effect of dietary starch on the productive yield and cecal microbial activity for rabbits in the growing, four experimental diets were formulated to contain increasing corn starch levels (23, 28, 33 and 38 % total starch levels in dry matter basis. A total of 32 White New Zealand rabbits were allotted to finishing cages in a completely randomized block design. The results showed a decreasing linear effect for the feed intake and feed:gain ratio, where values of 108.67g/d and 3.216, respectively, were recorded for animals fed 38% dietary starch. However, no difference was observed for the weight gain and carcass yield. Regarding to cecal microbial activity, pH and

  1. The Systemic Acquired Resistance Regulator OsNPR1 Attenuates Growth by Repressing Auxin Signaling through Promoting IAA-Amido Synthase Expression1[OPEN

    Science.gov (United States)

    2016-01-01

    Systemic acquired resistance is a long-lasting and broad-spectrum disease resistance to pathogens. Our previous study demonstrated that overexpression of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (OsNPR1), a master gene for systemic acquired resistance in rice (Oryza sativa), greatly enhanced resistance to bacterial blight caused by Xanthomonas oryzae pv oryzae. However, the growth and development of the OsNPR1 overexpression (OsNPR1-OX) plants were restrained, and the mechanism remained elusive. In this study, we dissected the OsNPR1-induced growth inhibition. We found that the OsNPR1-OX lines displayed phenotypes mimicking auxin-defective mutants, with decreases in root system, seed number and weight, internode elongation, and tiller number. Whole-genome expression analysis revealed that genes related to the auxin metabolism and signaling pathway were differentially expressed between the OsNPR1-OX and wild-type plants. Consistently, the indole-3-acetic acid (IAA) content was decreased and the auxin distribution pattern was altered in OsNPR1-OX plants. Importantly, we found that some GH3 family members, in particular OsGH3.8 coding IAA-amido synthetase, were constitutively up-regulated in OsNPR1-OX plants. Decreased OsGH3.8 expression by RNA interference could partially restore IAA level and largely rescue the restrained growth and development phenotypes but did not affect the disease resistance of OsNPR1-OX plants. Taken together, we revealed that OsNPR1 affects rice growth and development by disrupting the auxin pathway at least partially through indirectly up-regulating OsGH3.8 expression. PMID:27378815

  2. The Systemic Acquired Resistance Regulator OsNPR1 Attenuates Growth by Repressing Auxin Signaling through Promoting IAA-Amido Synthase Expression.

    Science.gov (United States)

    Li, Xiaozun; Yang, Dong-Lei; Sun, Li; Li, Qun; Mao, Bizeng; He, Zuhua

    2016-09-01

    Systemic acquired resistance is a long-lasting and broad-spectrum disease resistance to pathogens. Our previous study demonstrated that overexpression of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (OsNPR1), a master gene for systemic acquired resistance in rice (Oryza sativa), greatly enhanced resistance to bacterial blight caused by Xanthomonas oryzae pv oryzae However, the growth and development of the OsNPR1 overexpression (OsNPR1-OX) plants were restrained, and the mechanism remained elusive. In this study, we dissected the OsNPR1-induced growth inhibition. We found that the OsNPR1-OX lines displayed phenotypes mimicking auxin-defective mutants, with decreases in root system, seed number and weight, internode elongation, and tiller number. Whole-genome expression analysis revealed that genes related to the auxin metabolism and signaling pathway were differentially expressed between the OsNPR1-OX and wild-type plants. Consistently, the indole-3-acetic acid (IAA) content was decreased and the auxin distribution pattern was altered in OsNPR1-OX plants. Importantly, we found that some GH3 family members, in particular OsGH3.8 coding IAA-amido synthetase, were constitutively up-regulated in OsNPR1-OX plants. Decreased OsGH3.8 expression by RNA interference could partially restore IAA level and largely rescue the restrained growth and development phenotypes but did not affect the disease resistance of OsNPR1-OX plants. Taken together, we revealed that OsNPR1 affects rice growth and development by disrupting the auxin pathway at least partially through indirectly up-regulating OsGH3.8 expression.

  3. Half-Sandwich Alkyl, Amido, and Iodo Samarium(II) Complexes: Non-Conventional Sterically Governed Oxidation of (tBu4 Carb)2 Sm.

    Science.gov (United States)

    Selikhov, Alexander N; Mahrova, Tatyana V; Cherkasov, Anton V; Fukin, Georgy K; Maron, Laurent; Trifonov, Alexander A

    2017-01-26

    The half-sandwich tetra-tert-butylcarbazol-9-yl iodo complex [(tBu4 Carb)Sm(μ-I)(THF)2 ]2 (1) was synthesized by the salt metathesis reaction of tBu4 CarbK and SmI2 (THF)2 in THF. Complex 1 along with metallic Cu was also isolated from the oxidation reaction of (tBu4 Carb)2 Sm by CuI. The formation of stable radical tBu4 Carb(.) was detected in this non-conventional process, indicating preferential oxidation of anion tBu4 Carb(-) vs. Sm(II) . The treatment of 1 with two equivalents of dibenzo-18-crown-6 resulted in heterolytic dissociation of a η(5) -bond Sm-tBu4 Carb and afforded an ionic compound [tBu4 carb(-) ][SmI(crown)(THF)2 ](+) (4). Alkylation of 1 with o-NMe2 C6 H4 CH2 K (1:2 molar ratio) in THF allowed for the synthesis of half-sandwich Sm(II) alkyl complex (tBu4 Carb)SmCH2 (o-NMe2 C6 H4 CH2 )(THF)2 (5) in 55 % yield. The amido complex (tBu4 Carb)SmN(SiMe3 )2 (DME) (6) was obtained by the reaction of 1 with two molar equivalents of NaN(SiMe3 )2 in THF in 89 % yield. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Arabidopsis Acetyl-Amido Synthetase GH3.5 Involvement in Camalexin Biosynthesis through Conjugation of Indole-3-Carboxylic Acid and Cysteine and Upregulation of Camalexin Biosynthesis Genes

    Institute of Scientific and Technical Information of China (English)

    Mu-Yang Wang; Xue-Ting Liu; Ying Chen; Xiao-Jing Xu; Biao Yu; Shu-Qun Zhang; Qun Li; Zu-Hua He

    2012-01-01

    Camalexin (3-thiazol-2'-yl-indole) is the major phytoalexin found in Arabidopsis thaliana.Several key intermediates and corresponding enzymes have been identified in camalexin biosynthesis through mutant screening and biochemical experiments.Camalexin is formed when indole-3-acetonitrile (IAN)is catalyzed by the cytochrome P450 monooxygenase CYP71A13.Here,we demonstrate that the Arabidopsis GH3.5 protein,a multifunctional acetyl-amido synthetase,is involved in camalexin biosynthesis via conjugating indole-3-carboxylic acid (ICA) and cysteine (Cys) and regulating camalexin biosynthesis genes.Camalexin levels were increased in the activation-tagged mutant gh3.5-1D in both Col-0 and cyp71A13-2 mutant backgrounds after pathogen infection.The recombinant GH3.5 protein catalyzed the conjugation of ICA and Cys to form a possible intermediate indole-3-acyl-cysteinate (ICA(Cys)) in vitro.In support of the in vitro reaction,feeding with ICA and Cys increased camalexin levels in Col-0 and gh3.5-1D.Dihydrocamalexic acid (DHCA),the precursor of camalexin and the substrate for PAD3,was accumulated in gh3.5-1Dlpad3-1,suggesting that ICA(Cys) could be an additional precursor of DHCA for camalexin biosynthesis.Furthermore,expression of the major camalexin biosynthesis genes CYP79B2,CYP71A12,CYP71A13 and PAD3 was strongly induced in gh3.5-1D.Our study suggests that GH3.5 is involved in camalexin biosynthesis through direct catalyzation of the formation of ICA(Cys),and upregulation of the major biosynthetic pathway genes.

  5. Análise da forma e tamanho de grânulos de amidos de diferentes fontes botânicas Analysis of the shape and size of starch grains from different botanical species

    Directory of Open Access Journals (Sweden)

    Magali Leonel

    2007-09-01

    Full Text Available Neste trabalho, objetivou-se avaliar a forma e tamanho de grânulos de amido de diferentes fontes botânicas, visando fornecer informações que contribuam para aplicabilidade destas como matérias-primas amiláceas. As féculas foram obtidas a partir do processamento das tuberosas em planta piloto de extração. Para a análise da forma dos grânulos utilizou-se o microscópio eletrônico de varredura, com as amostras diluídas em álcool etílico e metalizadas com ouro. A análise do tamanho dos grânulos foi realizada em microscópio ótico, sendo as amostras diluídas em solução de água e glicerina. Foram realizadas 500 determinações das medidas de tamanho (diâmetro menor, diâmetro maior e diferenças entre diâmetros por fonte botânica. Os resultados obtidos mostraram diferentes formas para os grânulos de amidos e das tuberosas estudadas. Os grânulos de amido de menor tamanho foram os de taioba (Xanthosoma sp. 12,87 µm, e os de maior tamanho os de biri (Canna edulis 59,61 µm. Observou-se distribuição bastante regular para os grânulos de amido de ahipa (Pachyrhizus ahipa.An analysis was made of the shape and size of starch grains from different botanical species, aiming to improve the potential applicability of these species as starch raw materials. The starches were obtained from the processing of tubers in a pilot extraction plant. The shape of the starch grains was analyzed by scanning electron microscopy (SEM, to which end the samples were mounted on SEM stubs and coated with gold. The size of the starch grains was determined by optical microscopy, for which the samples were diluted in a water and glycerin solution. The sizes of 500 grains of each botanical species were measured to determine the largest and smallest diameters and the difference between diameters. The results revealed different starch grain shapes and sizes, with Xanthosoma sp showing the smallest (12.87 µm and Canna edulis the largest grain size (56

  6. Estudo da adição de vital glúten à farinha de arroz, farinha de aveia e amido de trigo na qualidade de pães

    Directory of Open Access Journals (Sweden)

    TEDRUS Guilherme de A. S.

    2001-01-01

    Full Text Available Farinhas de arroz e de aveia e amido de trigo foram adicionados de vital glúten e avaliados pelo Teste de Panificação. Usou-se como padrão uma amostra de farinha de trigo com características adequadas para produção de pão. Os níveis de adição de vital glúten foram de 10, 15, 17,5, 20 e 30% para a farinha de arroz e de 10, 20 e 30% para a farinha de aveia. Ao amido de trigo, extraído da farinha de trigo utilizada como padrão, foi adicionado vital glúten de forma a reconstituir o teor de glúten original da farinha. Os melhores resultados do teste de panificação foram obtidos com 17,5% de vital glúten na farinha de arroz e 20% de vital glúten na farinha de aveia. Foram obtidos pães com volumes específicos inferiores aos de trigo (2,67cm³/g para vital glúten + farinha de arroz, 3,07cm³/g para vital glúten + farinha de aveia e 4,14cm³/g para vital glúten + amido de trigo contra 5,15cm³/g para os de farinha de trigo. As melhores misturas foram analisadas quanto às suas características reológicas e comparadas com a farinha de trigo original. A mistura de amido de trigo e vital glúten apresentou características farinográficas extensográficas inferiores à farinha de trigo e deu origem a pães de menor volume e com estrutura compacta. No geral, a adição de vital glúten propiciou a obtenção de pães com características aceitáveis, embora inferiores às do pão de farinha de trigo. As características dos pães contendo vital glúten foram: pouca simetria e quebra praticamente inexistente. São necessários novos estudos sobre a interação do vital glúten com os demais componentes da farinha de trigo e sua influência na qualidade do produto final.

  7. Functional alteration of a dimeric insecticidal lectin to a monomeric antifungal protein correlated to its oligomeric status.

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    Nilanjana Banerjee

    Full Text Available BACKGROUND: Allium sativum leaf agglutinin (ASAL is a 25-kDa homodimeric, insecticidal, mannose binding lectin whose subunits are assembled by the C-terminal exchange process. An attempt was made to convert dimeric ASAL into a monomeric form to correlate the relevance of quaternary association of subunits and their functional specificity. Using SWISS-MODEL program a stable monomer was designed by altering five amino acid residues near the C-terminus of ASAL. METHODOLOGY/PRINCIPAL FINDINGS: By introduction of 5 site-specific mutations (-DNSNN-, a β turn was incorporated between the 11(th and 12(th β strands of subunits of ASAL, resulting in a stable monomeric mutant ASAL (mASAL. mASAL was cloned and subsequently purified from a pMAL-c2X system. CD spectroscopic analysis confirmed the conservation of secondary structure in mASAL. Mannose binding assay confirmed that molecular mannose binds efficiently to both mASAL and ASAL. In contrast to ASAL, the hemagglutination activity of purified mASAL against rabbit erythrocytes was lost. An artificial diet bioassay of Lipaphis erysimi with mASAL displayed an insignificant level of insecticidal activity compared to ASAL. Fascinatingly, mASAL exhibited strong antifungal activity against the pathogenic fungi Fusarium oxysporum, Rhizoctonia solani and Alternaria brassicicola in a disc diffusion assay. A propidium iodide uptake assay suggested that the inhibitory activity of mASAL might be associated with the alteration of the membrane permeability of the fungus. Furthermore, a ligand blot assay of the membrane subproteome of R. solani with mASAL detected a glycoprotein receptor having interaction with mASAL. CONCLUSIONS/SIGNIFICANCE: Conversion of ASAL into a stable monomer resulted in antifungal activity. From an evolutionary aspect, these data implied that variable quaternary organization of lectins might be the outcome of defense-related adaptations to diverse situations in plants. Incorporation of m

  8. Functional alteration of a dimeric insecticidal lectin to a monomeric antifungal protein correlated to its oligomeric status.

    Science.gov (United States)

    Banerjee, Nilanjana; Sengupta, Subhadipa; Roy, Amit; Ghosh, Prithwi; Das, Kalipada; Das, Sampa

    2011-04-07

    Allium sativum leaf agglutinin (ASAL) is a 25-kDa homodimeric, insecticidal, mannose binding lectin whose subunits are assembled by the C-terminal exchange process. An attempt was made to convert dimeric ASAL into a monomeric form to correlate the relevance of quaternary association of subunits and their functional specificity. Using SWISS-MODEL program a stable monomer was designed by altering five amino acid residues near the C-terminus of ASAL. By introduction of 5 site-specific mutations (-DNSNN-), a β turn was incorporated between the 11(th) and 12(th) β strands of subunits of ASAL, resulting in a stable monomeric mutant ASAL (mASAL). mASAL was cloned and subsequently purified from a pMAL-c2X system. CD spectroscopic analysis confirmed the conservation of secondary structure in mASAL. Mannose binding assay confirmed that molecular mannose binds efficiently to both mASAL and ASAL. In contrast to ASAL, the hemagglutination activity of purified mASAL against rabbit erythrocytes was lost. An artificial diet bioassay of Lipaphis erysimi with mASAL displayed an insignificant level of insecticidal activity compared to ASAL. Fascinatingly, mASAL exhibited strong antifungal activity against the pathogenic fungi Fusarium oxysporum, Rhizoctonia solani and Alternaria brassicicola in a disc diffusion assay. A propidium iodide uptake assay suggested that the inhibitory activity of mASAL might be associated with the alteration of the membrane permeability of the fungus. Furthermore, a ligand blot assay of the membrane subproteome of R. solani with mASAL detected a glycoprotein receptor having interaction with mASAL. Conversion of ASAL into a stable monomer resulted in antifungal activity. From an evolutionary aspect, these data implied that variable quaternary organization of lectins might be the outcome of defense-related adaptations to diverse situations in plants. Incorporation of mASAL into agronomically-important crops could be an alternative method to protect them

  9. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro

    Science.gov (United States)

    Tamaddon, M.; Burrows, M.; Ferreira, S. A.; Dazzi, F.; Apperley, J. F.; Bradshaw, A.; Brand, D. D.; Czernuszka, J.; Gentleman, E.

    2017-03-01

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS – which was released from scaffolds quickly – significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

  10. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro.

    Science.gov (United States)

    Tamaddon, M; Burrows, M; Ferreira, S A; Dazzi, F; Apperley, J F; Bradshaw, A; Brand, D D; Czernuszka, J; Gentleman, E

    2017-03-03

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS - which was released from scaffolds quickly - significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

  11. Age-dependent preferential dense-core vesicle exocytosis in neuroendocrine cells revealed by newly developed monomeric fluorescent timer protein.

    Science.gov (United States)

    Tsuboi, Takashi; Kitaguchi, Tetsuya; Karasawa, Satoshi; Fukuda, Mitsunori; Miyawaki, Atsushi

    2010-01-01

    Although it is evident that only a few secretory vesicles accumulating in neuroendocrine cells are qualified to fuse with the plasma membrane and release their contents to the extracellular space, the molecular mechanisms that regulate their exocytosis are poorly understood. For example, it has been controversial whether secretory vesicles are exocytosed randomly or preferentially according to their age. Using a newly developed protein-based fluorescent timer, monomeric Kusabira Green Orange (mK-GO), which changes color with a predictable time course, here we show that small GTPase Rab27A effectors regulate age-dependent exocytosis of secretory vesicles in PC12 cells. When the vesicles were labeled with mK-GO-tagged neuropeptide Y or tissue-type plasminogen activator, punctate structures with green or red fluorescence were observed. Application of high [K(+)] stimulation induced exocytosis of new (green) fluorescent secretory vesicles but not of old (red) vesicles. Overexpression or depletion of rabphilin and synaptotagmin-like protein4-a (Slp4-a), which regulate exocytosis positively and negatively, respectively, disturbed the age-dependent exocytosis of the secretory vesicles in different manners. Our results suggest that coordinate functions of the two effectors of Rab27A, rabphilin and Slp4-a, are required for regulated secretory pathway.

  12. Differing modes of interaction between monomeric Aβ(1-40) peptides and model lipid membranes: an AFM study.

    Science.gov (United States)

    Sheikh, Khizar; Giordani, Cristiano; McManus, Jennifer J; Hovgaard, Mads Bruun; Jarvis, Suzanne P

    2012-02-01

    Membrane interactions with β-amyloid peptides are implicated in the pathology of Alzheimer's disease and cholesterol has been shown to be key modulator of this interaction, yet little is known about the mechanism of this interaction. Using atomic force microscopy, we investigated the interaction of monomeric Aβ(1-40) peptides with planar mica-supported bilayers composed of DOPC and DPPC containing varying concentrations of cholesterol. We show that below the bilayer melting temperature, Aβ monomers adsorb to, and assemble on, the surface of DPPC bilayers to form layers that grow laterally and normal to the bilayer plane. Above the bilayer melting temperature, we observe protofibril formation. In contrast, in DOPC bilayers, Aβ monomers exhibit a detergent-like action, forming defects in the bilayer structure. The kinetics of both modes of interaction significantly increases with increasing membrane cholesterol content. We conclude that the mode and rate of the interaction of Aβ monomers with lipid bilayers are strongly dependent on lipid composition, phase state and cholesterol content.

  13. The full-length cell-cell fusogen EFF-1 is monomeric and upright on the membrane

    Science.gov (United States)

    Zeev-Ben-Mordehai, Tzviya; Vasishtan, Daven; Siebert, C. Alistair; Grünewald, Kay

    2014-05-01

    Fusogens are membrane proteins that remodel lipid bilayers to facilitate membrane merging. Although several fusogen ectodomain structures have been solved, structural information on full-length, natively membrane-anchored fusogens is scarce. Here we present the electron cryo microscopy three-dimensional reconstruction of the Caenorhabditis elegans epithelial fusion failure 1 (EFF-1) protein natively anchored in cell-derived membrane vesicles. This reveals a membrane protruding, asymmetric, elongated monomer. Flexible fitting of a protomer of the EFF-1 crystal structure, which is homologous to viral class-II fusion proteins, shows that EFF-1 has a hairpin monomeric conformation before fusion. These structural insights, when combined with our observations of membrane-merging intermediates between vesicles, enable us to propose a model for EFF-1 mediated fusion. This process, involving identical proteins on both membranes to be fused, follows a mechanism that shares features of SNARE-mediated fusion while using the structural building blocks of the unilaterally acting class-II viral fusion proteins.

  14. Rational design of a monomeric and photostable far-red fluorescent protein for fluorescence imaging in vivo.

    Science.gov (United States)

    Yu, Dan; Dong, Zhiqiang; Gustafson, William Clay; Ruiz-González, Rubén; Signor, Luca; Marzocca, Fanny; Borel, Franck; Klassen, Matthew P; Makhijani, Kalpana; Royant, Antoine; Jan, Yuh-Nung; Weiss, William A; Guo, Su; Shu, Xiaokun

    2016-02-01

    Fluorescent proteins (FPs) are powerful tools for cell and molecular biology. Here based on structural analysis, a blue-shifted mutant of a recently engineered monomeric infrared fluorescent protein (mIFP) has been rationally designed. This variant, named iBlueberry, bears a single mutation that shifts both excitation and emission spectra by approximately 40 nm. Furthermore, iBlueberry is four times more photostable than mIFP, rendering it more advantageous for imaging protein dynamics. By tagging iBlueberry to centrin, it has been demonstrated that the fusion protein labels the centrosome in the developing zebrafish embryo. Together with GFP-labeled nucleus and tdTomato-labeled plasma membrane, time-lapse imaging to visualize the dynamics of centrosomes in radial glia neural progenitors in the intact zebrafish brain has been demonstrated. It is further shown that iBlueberry can be used together with mIFP in two-color protein labeling in living cells and in two-color tumor labeling in mice.

  15. Influência da concentração de soro de leite e de amido modificado sobre algumas características de composição de bebidas lácteas não fermentadas

    Directory of Open Access Journals (Sweden)

    Shana P. Ferreira

    2009-12-01

    Full Text Available Este trabalho teve como objetivo estudar a influência da concentração de soro de leite (26, 30, 40, 50 e 54% e de amido modificado (0,1; 0,2; 0,4; 0,6 e 0,7% sobre os teores de lactose, sólidos totais e acidez titulável de bebidas lácteas não fermentadas. Foram elaboradas 11 formulações empregando-se o planejamento estatístico Delineamento Composto Central Rotacional (DCCR para avaliar a influência dos fatores estudados, sobre as variáveis avaliadas. Para análise estatística dos resultados realizou-se análise de regressão. Constatou-se que as concentrações de soro avaliadas apresentaram efeito significativo sobre os teores de lactose, sólidos totais e acidez titulável, e o amido modificado não apresentou efeito significativo.

  16. Efeito do tamanho dos grânulos nas características estruturais e físico-químicas do amido de trigo Effect of granule size on the structural and physicochemical characteristics of wheat starch

    Directory of Open Access Journals (Sweden)

    Patrícia Guedes Yonemoto

    2007-12-01

    Full Text Available A distribuição de tamanho dos grânulos influencia diretamente a composição química do amido, afetando sua funcionalidade, características de gelatinização, susceptibilidade enzimática, e cristalinidade. Os grânulos de amido de trigo possuem distribuição bimodal de tamanho e são divididos em grânulos tipo A (10-40 µm e B (15 µm e pequenos (Granule size distribution directly influences the chemical composition of starch, affecting its functionality, characteristics of gelatinization, enzymatic susceptibility and crystallinity. Wheat starch granules exhibit a bimodal size distribution and are divided into type A (10-40 µm and type B (15 µm and small granules (<10 µm. Starches of different sizes were analyzed to determine their lysophospholipid and amylose content, X-ray patterns, enzymatic susceptibility, swelling power, and thermal and pasting properties. They were also examined under a scanning electron microscope. Independent of the cultivar studied, large granules showed an average diameter of 22 µm and were lentil-shaped, while small granules showed an average diameter of 6 µm and were spherical. The large granules exhibited lower lysophospholipids content, higher amylose content and a lower index of crystallinity (IC than the small granules. Despite their higher crystallinity, small granules were more susceptible to hydrolysis than large ones, suggesting that the enzymatic susceptibility of small granules is related to its larger surface area.

  17. Métodos de determinação dos teores de amido e pectina em alimentos para animais (Determination methods of starch and pectin levels in animal feeds

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2006-01-01

    Full Text Available A separação dos carboidratos não fibrosos (CNF em frações nutricionalmente mais relevantes, por meio de análises de seus componentes, tais como ácidos orgânicos, mono e oligossacarídeos, amido e fibra solúvel contribuem para avanços na formulação de dietas. A pectina, embora seja um carboidrato associado à parede celular, não é covalentemente unida às porções lignificadas e é completamente digerida no rúmen (90 a 100%. Com a importância destes compostos na alimentação de ruminantes, esta revisão tem por objetivo descrever alguns métodos de avaliação de amido e pectina em alimentos para animais. The separation of non fiber carbohydrates (NFC in nutritionally more relevant fractions, by analysis of its components, such as organic acids, mono and oligosaccharides, starch and soluble fiber contribute to advances in diet formulation. Pectin, although an cellular wall associated carbohydrate, is not covalent linked to lignified portions and is completely digested in the rumen (90 and 100%. With the importance of these components in ruminant feeding, this revision has the objective of describe some starch and pectin evaluation methods in animal feeds

  18. Hydrolyzed collagen, modified starch and guar gum addition in turkey ham Adição de colágeno hidrolisado, amido modificado e goma guar em presunto de peru

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Prestes

    2012-07-01

    Full Text Available The main problems observed in cooked hams are bad sliceability and excessive fluid loss after cooking. To reduce these problems the industry uses non-meat ingredients such as soy protein and carrageenan, but under Brazilian law, it is not allowed to add starch or modified starch in hams. Three ingredients were tested in the present research: modified starch (0 to 2.0%, gum guar (0 to 0.30% and hydrolyzed collagen (0 to 2.0%, following a 2³ full factorial design with five repetitions in the central point. The guar gum produced low resistance to reheating, however in losses by cooling, the results were adequate. The hydrolyzed collagen tested did not give satisfactory results, showing low acceptance due to formation of gel in the ham and high losses. The developed products were not different from the commercial product in relation to texture (P>0.05. The formulation F6 (2.0% of modified starch was the one with the best results and greater acceptance as detected by the tasters. Based on the results obtained it seems appropriate to propose the legal permission of starch in ham or the creation of a new class of product in which starch addition would be allowed.Os principais problemas observados em presuntos são a má fatiabilidade e a perda excessiva de líquidos após o cozimento. Para reduzir esses problemas, a indústria utiliza ingredientes não cárneos, tais como a proteína de soja e a carragena, porém, segundo a legislação brasileira, não é permitida a adição de amido ou amido modificado. Neste trabalho, foram testados três ingredientes, em presunto cozido de peru: amido modificado (0 a 2,0%, goma guar (0 a 0,30% e colágeno hidrolisado (0 a 2,0%, seguindo um delineamento fatorial completo 2³ com cinco repetições no ponto central. A goma guar apresentou baixa resistência ao reaquecimento, no entanto, nas perdas por resfriamento, os resultados foram adequados. O colágeno hidrolisado testado não proporcionou resultados satisfat

  19. CD44-Targeted Hyaluronic Acid-Coated Redox-Responsive Hyperbranched Poly(amido amine)/Plasmid DNA Ternary Nanoassemblies for Efficient Gene Delivery.

    Science.gov (United States)

    Gu, Jijin; Chen, Xinyi; Ren, Xiaoqing; Zhang, Xiulei; Fang, Xiaoling; Sha, Xianyi

    2016-07-20

    Hyaluronic acid (HA), which can specifically bind to CD44 receptor, is a specific ligand for targeting to CD44-overexpressing cancer cells. The current study aimed to develop ternary nanoassemblies based on HA-coating for targeted gene delivery to CD44-positive tumors. A novel reducible hyperbranched poly(amido amine) (RHB) was assembled with plasmid DNA (pDNA) to form RHB/pDNA nanoassemblies. HA/RHB/pDNA nanoassemblies were fabricated by coating HA on the surface of the RHB/pDNA nanoassembly core through electrostatic interaction. After optimization, HA/RHB/pDNA nanoassemblies were spherical, core-shell nanoparticles with nanosize (187.6 ± 11.4 nm) and negative charge (-9.1 ± 0.3 mV). The ternary nanoassemblies could efficiently protect the condensed pDNA from enzymatic degradation by DNase I, and HA could significantly improve the stability of nanoassemblies in the sodium heparin solution or serum in vitro. As expected, HA significantly decreased the cytotoxicity of RHB/pDNA nanoassemblies due to the negative surface charges. Moreover, it revealed that HA/RHB/pDNA nanoassemblies showed higher transfection activity than RHB/pDNA nanoassemblies in B16F10 cells, especially in the presence of serum in vitro. Because of the active recognition between HA and CD44 receptor, there was significantly different transfection efficiency between B16F10 (CD44+) and NIH3T3 (CD44-) cells after treatment with HA/RHB/pDNA nanoassemblies. In addition, the cellular targeting and transfection activity of HA/RHB/pDNA nanoassemblies were further evaluated in vivo. The results indicated that the interaction between HA and CD44 receptor dramatically improved the accumulation of HA/RHB/pDNA nanoassemblies in CD44-positive tumor, leading to higher gene expression than RHB/pDNA nanoassemblies. Therefore, HA/RHB/pDNA ternary nanoassemblies may be a potential gene vector for delivery of therapeutic genes to treat CD44-overexpressing tumors in vivo.

  20. Caracterização do grânulo de amido de bananas (Musa AAA-Nanicão e Musa AAB-Terra Characterization of starch granules from bananas Musa AAA-Nanicão and Musa AAB-Terra

    Directory of Open Access Journals (Sweden)

    M.C.J. Freitas

    2005-06-01

    Full Text Available O amido de bananas tem sido pesquisado na área de nutrição a partir da introdução do conceito de Amido Resistente. O amido de Musa AAA-Nanicão e Musa AAB-Terra foram caracterizados quanto as suas respostas fisiológicas [12]. Em continuidade, o presente trabalho estudou características físicas e morfológicas dos grânulos de amido de ambas as espécies de banana comparando-as com amido nativo de milho comercial. O amido de bananas foi extraído segundo CHIANG, CHU & CHU [3]. A morfologia dos grânulos foi realizada após tratamento enzimático in vitro a 37°C/24h com alfa-amilase pancreática. Foram efetuados os respectivos amilogramas e difractogramas de raios-X. Os grânulos de amido da Musa Tipo AAA-Nanicão apresentaram comprimento entre 30-40µm. Em Musa AAB-Terra, os grânulos, também ovais e alongados, eram um pouco menores, 20-30µm. A corrosão enzimática in vitro iniciava-se sobre a superfície anteriormente lisa e formavam estrias superficiais e apicais. A Microscopia Eletrônica de Varredura (MEV mostrou que a hidrólise in vitro por 24 horas foi pequena e ocorria sobretudo nas camadas amorfas dos grânulos de ambas as espécies. O padrão de corrosão demonstrou-se distinto daquele ocorrido no amido de milho. As suspensões de amido de bananas ao viscosímetro demonstraram forte capacidade de hidratação e menor capacidade de retrogradação em relação ao milho, sobretudo do amido de Musa Tipo AAA-Nanicão; o amido de Musa Tipo AAB-Terra apresentou maior estabilidade de pasta. Na análise de difração de raios-X, os grânulos de bananas apresentaram padrão tipo B e C para Musa Tipo AAA-Nanicão e Musa Tipo AAB-Terra, respectivamente. Conclui-se que os amidos de Musa AAA-Nanicão e Musa AAB-Terra são estruturalmente distintos, justificando as respostas fisiológicas distintas encontradas posteriormente pelos mesmos autores. As distinções das propriedades físicas e bioquímicas obtidas para os grânulos, embora

  1. New strategy for high-level expression and purification of biologically active monomeric TGF-β1/C77S in Escherichia coli.

    Science.gov (United States)

    Kim, Yana V; Gasparian, Marine E; Bocharov, Eduard V; Chertkova, Rita V; Tkach, Elena N; Dolgikh, Dmitry A; Kirpichnikov, Mikhail P

    2015-02-01

    Mature transforming growth factor beta1 (TGF-β1) is a homodimeric protein with a single disulfide bridge between Cys77 on the respective monomers. The synthetic DNA sequence encoding the mature human TGF-β1/C77S (further termed TGF-β1m) was cloned into plasmid pET-32a downstream to the gene of fusion partner thioredoxin (Trx) immediately after the DNA sequence encoding enteropeptidase recognition site. High-level expression (~1.5 g l(-1)) of Trx/TGF-β1m fusion was achieved in Escherichia coli BL21(DE3) strain mainly in insoluble form. The fusion was solubilized and refolded in glutathione redox system in the presence of zwitterionic detergent CHAPS. After refolding, Trx/TGF-β1m fusion was cleaved by enteropeptidase, and the carrier protein of TGF-β1m was separated from thioredoxin on Ni-NTA agarose. Separation of monomeric molecules from the noncovalently bounded oligomers was done using cation-exchange chromatography. The structure of purified TGF-β1m was confirmed by circular dichroism analysis. The developed technology allowed purifying biologically active tag-free monomeric TGF-β1m from bacteria with a yield of about 2.8 mg from 100 ml cell culture. The low-cost and easy purification steps allow considering that our proposed preparation of recombinant monomeric TGF-β1 could be employed for in vitro and in vivo experiments as well as for therapeutic intervention.

  2. Granules morphology and rheological behavior of green banana (Musa cavendishii and corn (Zea mays starch gels Morfologia dos grânulos e comportamento reológico dos géis de amido de banana verde (Musa cavendishii e milho (Zea mays

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    Dayane Rosalyn Izidoro

    2007-10-01

    Full Text Available In this work, it was used starch obtained from green banana (Musa cavendishii and commercial corn (Zea mays starch in order to compare the granule morphology and the rheological behavior of these gel-starches. Images of starch granules morphology were obtained from scanning electron microscope (SEM. The banana starch granules presented an oval and ellipsoidal shape with irregular diameters. Neverthless, the granules of corn starch showed a poliedric shape, with different sizes. The rheological behavior of gel starch solutions showed a non-newtonian character with a pseudoplastic behavior. Herschel-Bulkley model gave a good description on the rheological behavior of the gel starch. Banana gel-starch solutions showed higher values of shear stress and apparent viscosity when compared with corn gel-starch solutions. A progressive decrease in shear stress and viscosity occurred with the addition of sodium chloride and sucrose.No presente trabalho foi utilizado amido obtido de banana verde (Musa cavendishii e amido de milho (Zea mays comercial, com o objetivo de comparar a morfologia dos grânulos e o comportamento reológico dos géis. As imagens da morfologia dos grânulos foram obtidas por microscopia eletrônica de varredura. Os grânulos de amido da banana apresentaram forma oval e elipsoidal com diâmetros irregulares, todavia, os grânulos do amido de milho mostraram forma poliédrica e diferentes tamanhos. As análises reológicas dos géis das soluções de amido mostraram caráter não-newtoniano, pseudoplástico. O modelo de Herschel-Bulkley foi o que melhor representou comportamento reológico dos géis. O gel de amido de banana verde obteve maiores valores de tensão de cisalhamento e viscosidade aparente quando comparada ao gel de amido de milho. Ocorreu um decréscimo progressivo na tensão de cisalhamento e na viscosidade com a adição de cloreto de sódio e sacarose aos géis.

  3. Effect of addition of different hydrocolloids on pasting, thermal, and rheological properties of cassava starch Efeito da adição de diferentes hidrocoloides sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca

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    Tatiana Dias Leite

    2012-09-01

    Full Text Available Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture, and water mobility. Starch-gum interaction in food systems can change the starch granule swelling and its gelatinization and rheological properties. In this study, the effect of the addition of xanthan gum (XG, sodium carboxymethyl cellulose (SCMC, and carrageenan (CAR at the concentrations of the 0.15, 0.25, 0.35 and 0.45% (w/v on the pasting, thermal, and rheological properties of cassava starch was studied. The swelling power (SP and the scanning electron microscopy (SEM of the starch gels were also evaluated. The results obtained showed that xanthan gum (XG had a strong interaction with the cassava starch penetrating between starch granules causing increase in pasting viscosities, SP, storage and loss (G', and G", respectively modulus and reduction in the setback of the starch; sodium carboxymethyl cellulose (SCMC greatly increased the pasting viscosities, the SP, and the storage and loss (G', and G", respectively modulus of the starch-mixtures, mainly due to its greater capacity to hold water and not due to the interaction with cassava starch. Carrageenan (CAR did not change any of the starch properties since there was no interaction between this gum and cassava starch at the concentrations used.Amidos e gomas são hidrocoloides frequentemente usados em sistemas alimentícios com a finalidade de fornecer textura, umidade e mobilidade de água. A interação amido-goma em sistemas alimentícios pode alterar o inchamento do grânulo de amido e as suas propriedades de gelatinização e reológicas. Neste trabalho, o efeito da adição de goma xantana (GX, carboximetilcelulose sódica (CMC e carragena (CAR nas concentrações de 0,15, 0,25, 0,35 e 0,45% (p/v sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca foi estudado. O Poder de inchamento (PI e a Microscopia Eletrônica de Varredura (MEV dos géis de amido tamb

  4. The effect of acid hydrolysis on the technological functional properties of pinhão (Araucaria brasiliensis starch Efeito da hidrólise ácida nas propriedades funcionais tecnológicas do amido de pinhão (Araucaria brasiliensis

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    Roberta Cruz Silveira Thys

    2013-02-01

    Full Text Available Technological functional properties of native and acid-thinned pinhão (seeds of Araucária angustifolia, Brazilian pine starches were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed (3.2 mol.L-1 HCl, 44 ºC, 6 hours and evaluated before and after the hydrolysis reaction in terms of formation, melting point and thermo-reversibility of gel starches, retrogradation (in a 30-day period and measurements every three days, paste freezing and thawing stability (after six freezing and thawing cycles, swelling power, and solubility. The results of light transmittance (% of pastes of native and acid-thinned pinhão starches was higher (lower tendency to retrogradation than that obtained for corn starches after similar storage period. Native pinhão starch (NPS presented lower syneresis than native corn starch (NCS when submitted to freeze-thaw cycles. The acid hydrolysis increased the syneresis of the two native varieties under storage at 5 ºC and after freezing and thawing cycles. The solubility of NPS was lower than that of native corn starch at 25, 50, and 70 ºC. However, for the acid-thinned pinhão starch (APS, this property was significantly higher (p As propriedades funcionais tecnológicas do amido nativo e modificado (hidrólise ácida de pinhão (Araucaria angustifólia foram comparadas às propriedades do amido nativo e ácido hidrolisado de milho. As espécies de amido foram hidrolisadas (3.2 mol.L-1 HCl, 44 ºC, 6 horas e avaliadas, antes e após a reação de hidrólise, de acordo com as análises de formação, fusão e termorreversão do gel, retrogradação (em um período de 30 dias, com medidas a cada 3 dias, estabilidade ao congelamento e descongelamento (após 6 ciclos de congelamento e descongelamento, poder de inchamento e índice de solubilidade. Os resultados obtidos demonstraram que o amido de pinhão apresenta menor tendência à retrogradação quando comparado ao amido

  5. Recognition profile of Morus nigra agglutinin (Morniga G) expressed by monomeric ligands, simple clusters and mammalian polyvalent glycotopes.

    Science.gov (United States)

    Singh, Tanuja; Wu, June H; Peumans, Willy J; Rougé, Pierre; Van Damme, Els J M; Wu, Albert M

    2007-01-01

    The carbohydrate binding properties of a novel member of the subfamily of galactose-specific jacalin-related lectin isolated from the bark of black mulberry (Morus nigra) (Morniga G) was studied in detail by enzyme-linked lectinosorbent and inhibition assays using panels of monomeric saccharides, mammalian polyvalent glycotopes and polysaccharides. Among the natural glycans tested for lectin binding, Morniga G reacted best with glycoproteins (gps) presenting a high density of tumor-associated carbohydrate antigens Tn (GalNAcalpha1-Ser/Thr) and Talpha (Galbeta1-3GalNAcalpha1-). Their reactivities, on a nanogram basis, were up to 72.5, 3.9x10(3), 6.0x10(3), 8.8x10(3) and 2.9x10(4) times higher than that of Tn-containing glycopeptides (M.W.Man/Glc, GlcNAc and lFuc; (ii) the mammalian glycotope specificity is Talpha1-benzyl>T>Tn>GalNAcbeta1-3Gal (P), while B/E (Galalpha1-3/4Gal), I/II (Galbeta1-3/4GlcNAc), S (GalNAcbeta1-4Gal), F/A (GalNAcalpha1-3GalNAc/Gal) and L (Galbeta1-4Glc) are inactive; (iii) the most active ligand is T/Tn; (iv) simple clustered Tn or triantennary N-glycans with II termini (Tri-II) have limited impact; (v) high-density polyvalent glycotopes play a prominent role for enhancing Morniga G reactivity. These results provide evidence for the binding of this lectin to dense cell surface T/Tn glycoconjugates and facilitate future usage of this lectin in biotechnological and medical applications.

  6. Pleiotropic benefit of monomeric and oligomeric flavanols on vascular health--a randomized controlled clinical pilot study.

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    Antje R Weseler

    Full Text Available BACKGROUND: Cardiovascular diseases are expanding to a major social-economic burden in the Western World and undermine man's deep desire for healthy ageing. Epidemiological studies suggest that flavanol-rich foods (e.g. grapes, wine, chocolate sustain cardiovascular health. For an evidenced-based application, however, sound clinical data on their efficacy are strongly demanded. METHODS: In a double-blind, randomized, placebo-controlled intervention study we supplemented 28 male smokers with 200 mg per day of monomeric and oligomeric flavanols (MOF from grape seeds. At baseline, after 4 and 8 weeks we measured macro- and microvascular function and a cluster of systemic biomarkers for major pathological processes occurring in the vasculature: disturbances in lipid metabolism and cellular redox balance, and activation of inflammatory cells and platelets. RESULTS: In the MOF group serum total cholesterol and LDL decreased significantly (P ≤ 0.05 by 5% (n = 11 and 7% (n = 9, respectively in volunteers with elevated baseline levels. Additionally, after 8 weeks the ratio of glutathione to glutathione disulphide in erythrocytes rose from baseline by 22% (n = 15, P<0.05 in MOF supplemented subjects. We also observed that MOF supplementation exerts anti-inflammatory effects in blood towards ex vivo added bacterial endotoxin and significantly reduces expression of inflammatory genes in leukocytes. Conversely, alterations in macro- and microvascular function, platelet aggregation, plasma levels of nitric oxide surrogates, endothelin-1, C-reactive protein, fibrinogen, prostaglandin F2alpha, plasma antioxidant capacity and gene expression levels of antioxidant defense enzymes did not reach statistical significance after 8 weeks MOF supplementation. However, integrating all measured effects into a global, so-called vascular health index revealed a significant improvement of overall vascular health by MOF compared to placebo (P ≤ 0.05. CONCLUSION: Our

  7. Aggregation of a slow-folding mutant of a beta-clam protein proceeds through a monomeric nucleus.

    Science.gov (United States)

    Ignatova, Zoya; Gierasch, Lila M

    2005-05-17

    Mechanistic understanding of protein aggregation, leading either to structured amyloid fibrils or to amorphous inclusion body-like deposits, should facilitate the identification of potential therapeutic intervention strategies for the devastating amyloid-based diseases. Here we focus on the in vitro aggregation of a slow-folding mutant of the beta-clam protein, cellular retinoic acid-binding protein I (P39A CRABP I), which forms inclusion bodies when expressed in Escherichia coli. Aggregation was monitored by observing the fluorescence of a fluorescein-based biarsenical dye (FlAsH) that ligates to a tetra-Cys motif, here incorporated into a flexible Omega-loop. The fluorescence signal of FlAsH on the tetra-Cys-containing P39A CRABP I is sensitive to whether this protein is native or unfolded, and was used in combination with other techniques to follow aggregate formation. The aggregation time course is compatible with a nucleation-dependent polymerization model, and detailed kinetic analysis showed that the energetically unfavorable nucleus is monomeric. A similar conclusion was reached previously for poly(Gln) species [Chen, S., Ferrone, F. A., and Wetzel, R. (2002) Proc. Natl. Acad. Sci. U.S.A. 99, 11884-11889] and points to an unfavorable equilibrium between the misfolded intermediate and the bulk pool of monomers as causative in aggregation. The P39A mutation, which removes a helix-stop signal, may slow closure of the beta-barrel in P39A CRABP I relative to the wild type, leaving it vulnerable to aggregation. Wide-angle X-ray scattering showed that the amorphous aggregates formed by the aggregation-prone intermediates of P39A CRABP I contain predominantly beta-strands structured in a lamellar fashion with 10.03 A spacing between adjacent beta-sheets.

  8. Occurrence and Speciation of Polymeric Chromium(III), Monomeric Chromium(III) and Chromium(VI) in Environmental Samples

    Science.gov (United States)

    HU, LIGANG; CAI, YONG; JIANG, GUIBIN

    2016-01-01

    Laboratory experiments suggest that polymeric Cr(III) could exist in aqueous solution for a relative long period of time. However, the occurrence of polymeric Cr(III) has not been reported in environmental media due partially to the lack of method for speciating polymeric Cr. We observed an unknown Cr species during the course of study on speciation of Cr in the leachates of chromated-copper-arsenate (CCA)-treated wood. Efforts were made to identify structure of the unknown Cr species. Considering the forms of Cr existed in the CCA-treated woods, we mainly focused our efforts to determine if the unknown species were polymeric Cr(III), complex of Cr/As or complex of Cr with dissolved organic matter (DOM). In order to evaluate whether polymeric Cr(III) largely exist in wood leachates, high performance liquid chromatography coupled with inductively coupled mass spectrometry (HPLC-ICPMS was used) for simultaneous speciation of monomeric Cr(III), polymeric Cr(III), and Cr(VI). In addition to wood leachates where polymeric Cr (III) ranged from 39.1 to 67.4 %, occurrence of the unknown Cr species in other environmental matrices, including surface waters, tap and waste waters, was also investigated. It was found that polymeric Cr(III) could exist in environmental samples containing μg/L level of Cr, at a level up to 60% of total Cr, suggesting that polymeric Cr(III) could significantly exist in natural environments. Failure in quantifying polymeric Cr(III) would lead to the underestimation of total Cr and bias in Cr speciation. The environmental implication of the presence of polymeric Cr(III) species in the environment deserves further study. PMID:27156211

  9. Stability, structural and functional properties of a monomeric, calcium–loaded adenylate cyclase toxin, CyaA, from Bordetella pertussis

    Science.gov (United States)

    Cannella, Sara E.; Ntsogo Enguéné, Véronique Yvette; Davi, Marilyne; Malosse, Christian; Sotomayor Pérez, Ana Cristina; Chamot-Rooke, Julia; Vachette, Patrice; Durand, Dominique; Ladant, Daniel; Chenal, Alexandre

    2017-01-01

    Bordetella pertussis, the causative agent of whooping cough, secretes an adenylate cyclase toxin, CyaA, which invades eukaryotic cells and alters their physiology by cAMP overproduction. Calcium is an essential cofactor of CyaA, as it is the case for most members of the Repeat-in-ToXins (RTX) family. We show that the calcium-bound, monomeric form of CyaA, hCyaAm, conserves its permeabilization and haemolytic activities, even in a fully calcium-free environment. In contrast, hCyaAm requires sub-millimolar calcium in solution for cell invasion, indicating that free calcium in solution is involved in the CyaA toxin translocation process. We further report the first in solution structural characterization of hCyaAm, as deduced from SAXS, mass spectrometry and hydrodynamic studies. We show that hCyaAm adopts a compact and stable state that can transiently conserve its conformation even in a fully calcium-free environment. Our results therefore suggest that in hCyaAm, the C-terminal RTX-domain is stabilized in a high-affinity calcium-binding state by the N-terminal domains while, conversely, calcium binding to the C-terminal RTX-domain strongly stabilizes the N-terminal regions. Hence, the different regions of hCyaAm appear tightly connected, leading to stabilization effects between domains. The hysteretic behaviour of CyaA in response to calcium is likely shared by other RTX cytolysins. PMID:28186111

  10. Production of Monomeric Aromatic Compounds from Oil Palm Empty Fruit Bunch Fiber Lignin by Chemical and Enzymatic Methods.

    Science.gov (United States)

    Tang, Pei-Ling; Hassan, Osman; Maskat, Mohamad Yusof; Badri, Khairiah

    2015-01-01

    In this study, oil palm empty fruit bunch (OPEFBF) was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen) and enzymatic [cutinase versus manganese peroxidase (MnP)] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt.) and reaction time (30, 90, and 180 minutes) on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17 ± 49.44 ppm hydroxybenzoic acid, 5.67 ± 0.25 ppm p-hydroxybenzaldehyde, 25.57 ± 1.64 ppm vanillic acid, 168.68 ± 23.23 ppm vanillin, 75.44 ± 6.71 ppm syringic acid, 815.26 ± 41.77 ppm syringaldehyde, 15.21 ± 2.19 ppm p-coumaric acid, and 44.75 ± 3.40 ppm ferulic acid), among the tested methods. High sodium hydroxide concentration (10% wt.) was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid). Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g(-1) lignin at pH 8 and 55°C for 24 hours, about 642.83 ± 14.45 ppm hydroxybenzoic acid, 70.19 ± 3.31 ppm syringaldehyde, 22.80 ± 1.04 ppm vanillin, 27.06 ± 1.20 ppm p-coumaric acid, and 50.19 ± 2.23 ppm ferulic acid were produced.

  11. MISTURAS DE FARINHA DE AVEIA E AMIDO DE MILHO COM ALTO TEOR DE AMILOPECTINA PARA PRODUÇÃO DE "SNACKS" OAT FLOUR/WAXY CORN STARCH BLENDS FOR SNACKS PRODUCTION

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    Laura Beatriz KARAM

    2001-08-01

    Full Text Available O potencial de uso do amido modificado com alto teor de amilopectina combinado à farinha de aveia para produção de "snacks" extrusados foi investigado. O processamento foi executado em extrusor mono-rosca, de acordo com um delienamento fatorial (2(5 incompleto, com 3 repetições no ponto central. As variáveis independentes controladas foram: umidade da matéria-prima, temperatura de extrusão, rotação do parafuso, diâmetro da matriz e teor de amido modificado. Como respostas, avaliou-se o volume específico, a dureza e a fraturabilidade. A partir da modelagem exploratória foram definidas as variáveis significativas e novos deslocamentos na área experimental, até se atingir o ponto ótimo para produção de "snacks". A melhor combinação de variáveis encontrada, para obter um produto com boas propriedades de expansão e de textura, foi: 17% de umidade de matéria-prima, 183°C de temperatura de extrusão, 100rpm de rotação do parafuso, 4mm de diâmetro da matriz e 30% de amido modificado. O produto obtido nessas condições apresentou 7,2mL/g de volume específico, 5,41N de dureza e 2,02N de fraturabilidade, assemelhando-se, por essas características, aos produtos comerciais de milho.The potential application of modified starch to enhance properties of oat flour extruded products was investigated. The process was performed using a single screw extruder, applying a 2(5 factorial design with 3 repetitions on the central point. The independent variables were: feed moisture, extrusion temperature, screw speed, die diameter and modified starch level and depended studied variables were: specific volume, hardness and fracturability. Based on results of the experiments a new experimental design was proposed to optimize product characteristics. The best combination of variables to obtain snacks with good expansion and texture was: 17% feed moisture, 183°C temperature, 100rpm screw speed, 4mm die diameter and 30% waxy starch. The product

  12. Estrutura dos grânulos de amido e sua relação com propriedades físico-químicas Starch granules structure and its regards with physicochemical properties

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    Cristiane Casagrande Denardin

    2009-06-01

    Full Text Available Devido aos escassos trabalhos brasileiros sobre a estrutura dos grânulos de amido, o objetivo desta revisão foi demonstrar os avanços atuais na elucidação da arquitetura e da estrutura química desse polímero. Muitas pesquisas sobre a avaliação da relação existente entre a estrutura molecular do amido e seu comportamento em algumas propriedades físico-químicas sugerem que diversas características estruturais, tais como teor de amilose, distribuição de comprimento das cadeias de amilopectina e grau de cristalinidade no grânulo, estejam intimamente relacionadas a eventos associados à gelatinização e retrogradação, como inchamento do grânulo, lixiviação de amilose e/ou amilopectina, perda da estrutura radial (birrefringência, supra-molecular (cristalinidade e molecular e recristalização. O foco principal desta revisão foi a compilação de estudos a fim de obter melhor entendimento da estrutura e das características dos componentes do amido e sua relação com propriedades físico-químicas, principalmente no que diz respeito à gelatinização e retrogradação, as quais apresentam grande importância nutricional e tecnológica.Due to poor Brazilians work on the structure of starch granules, the purpose of this review was to demonstrate the advances in current understanding of architecture and chemical structure of this polymer. Many studies evaluating the relationship between the molecular structure of starch and its behavior in some physicochemical properties, suggest that several structural features, such as amylose content, amylopectin chain length distribution and the degree of crystallinity in the granule, are closely related to the events associated with gelatinization and retrogradation as starch granule swelling, amylose and/or amylopectin leaching, loss of radial structure (birefringence, supra-molecular (crystallinity and molecular order, and recrystallization. The main focus of this review was to make a

  13. Blendas compatíveis de amido termoplástico e polietileno de baixa densidade compatibilizadas com ácido cítrico Compatible blends of thermoplastic starch and low density polyethylene compatibilized with citric acid

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    Vinícius R. Miranda

    2011-01-01

    Full Text Available Blendas de polietileno de baixa densidade (PEBD e amido termoplástico (TPS modificado foram preparadas via extrusão reativa (REX e caracterizadas por microscopia eletrônica de varredura (MEV, espectroscopia na região do infravermelho com transformada de Fourier (FTIR, absorção de umidade em ambiente com 53% de umidade relativa e difração de raios-X. Em uma primeira etapa, foi preparado o TPS- modificado, via REX a partir de uma mistura de amido de milho, ácido cítrico e glicerol. As blendas TPS-PEBD foram preparadas pelo processamento de uma mistura do TPS modificado e PEBD, ambos em peletes, em uma extrusora de rosca simples. Foi observado um significativo efeito de compatibilização, atribuído especialmente à redução da viscosidade da fase TPS e consequente redução da tensão interfacial entre as fases de TPS e PEBD. Os espectros de FTIR apresentaram deslocamentos de bandas de absorção do amido confirmando o efeito de compatibilização pelo ácido cítrico. Observou-se também significativa alteração da morfologia das blendas, especialmente para as blendas preparadas com adição de 1,0 - 1,5 % de ácido cítrico, que apresentaram estrutura da fase dispersa mais fina e homogênea.Blends of citric acid-modified thermoplastic starch (TPS and low density polyethylene (LDPE were prepared by reactive extrusion (REX and characterized by scanning electron microscopy (SEM of the fragile fracture surfaces, Fourier-transform infrared spectroscopy (FTIR, water absorption in 53% relative humidity environment and by X-ray diffraction. The modified TPS was prepared by the reactive extrusion of a mixture of corn starch, citric acid and glycerol (30%. TPS-LDPE blends were then prepared by the processing of TPS and PEBD both in pellets in a single screw extruder. It was observed an important compatibilization effect, attributed to the reduction of TPS melt viscosity and consequently the reduction of the interfacial tension between TPS and

  14. Fracionamento a seco da farinha de aveia e modificação química da fração rica em amido Dry fractionation of oatmeal and chemical modification of starch rich fraction

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    Ana Paula Daniel

    2006-12-01

    Full Text Available O estudo teve por objetivo obter frações de farinha de aveia enriquecidas em amido e em fibras pelo fracionamento a seco e modificar quimicamente (fosfatação o amido da fração rica neste constituinte, avaliando suas propriedades funcionais. O fracionamento foi efetuado utilizando-se as granulometrias > 300, 212-300, 150-212, e 300 µm e 212-300 µm foram semelhantes, com aumento de aproximadamente 1,5 e 2,7 vezes nos teores de proteína e fibra, e redução de 0,5-0,6 vezes no teor de amido, quando comparadas à farinha integral. As frações 212-150 µm e The objective of this study was to obtain starch and fiber enriched oatmeal fractions through sieving, chemically modifying (phosphorylation the starch enriched fraction, and evaluating its functional properties. Fractionation was performed using > 300, 212-300, 150-212, and 300 µm and 212-300 µm were similar and had increased protein and fiber content (1.5 and 2.7 fold, but reduced starch content (0.5-0.6 fold when compared to whole oatmeal. Fractions 212-150 µm and < 150 µm were similar and had the highest starch content (around 70%. The starch-rich fraction < 150 µm that had the highest yield during sieving (35.5% was phosphorylated with sodium tripolyphosphate at 150-155 °C for 20 and 40 min, yielding 0.39 and 0.32% phosphorus bound, respectively. Cold water binding capacity increased (1.9-3.3 fold, while syneresis at 5 °C or after freezing/thawing was significantly reduced (6-20 and 5-6 fold, respectively in phosphorylated starch fraction when compared to the native starch fraction. Phosphorylation reduced the increase of pasta opacity during storage at 5 °C, which indicates a lower retrogradation tendency. Thus, oatmeal sieving yielded fractions either enriched in fiber and protein or enriched in starch. Moreover, phosphorylation of the starch-rich fraction improved their functional properties, which may increase the potential applicability and economic value of this

  15. Production of rhesus monkey cloned embryos expressing monomeric red fluorescent protein by interspecies somatic cell nuclear transfer

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hai-Ying; Kang, Jin-Dan; Li, Suo; Jin, Jun-Xue; Hong, Yu; Jin, Long; Guo, Qing; Gao, Qing-Shan; Yan, Chang-Guo; Yin, Xi-Jun, E-mail: yinxj33@msn.com

    2014-02-21

    Highlights: • Rhesus monkey cells were electroporated with a plasmid containing mRFP1, and an mRFP1-expressing cell line was generated. • For the first time, mRFP1-expressing rhesus monkey cells were used as donor cells for iSCNT. • The effect of VPA on the development of embryos cloned using iSCNT was determined. - Abstract: Interspecies somatic cell nuclear transfer (iSCNT) is a promising method to clone endangered animals from which oocytes are difficult to obtain. Monomeric red fluorescent protein 1 (mRFP1) is an excellent selection marker for transgenically modified cloned embryos during somatic cell nuclear transfer (SCNT). In this study, mRFP-expressing rhesus monkey cells or porcine cells were transferred into enucleated porcine oocytes to generate iSCNT and SCNT embryos, respectively. The development of these embryos was studied in vitro. The percentage of embryos that underwent cleavage did not significantly differ between iSCNT and SCNT embryos (P > 0.05; 71.53% vs. 80.30%). However, significantly fewer iSCNT embryos than SCNT embryos reached the blastocyst stage (2.04% vs. 10.19%, P < 0.05). Valproic acid was used in an attempt to increase the percentage of iSCNT embryos that developed to the blastocyst stage. However, the percentages of embryos that underwent cleavage and reached the blastocyst stage were similar between untreated iSCNT embryos and iSCNT embryos treated with 2 mM valproic acid for 24 h (72.12% vs. 70.83% and 2.67% vs. 2.35%, respectively). These data suggest that porcine-rhesus monkey interspecies embryos can be generated that efficiently express mRFP1. However, a significantly lower proportion of iSCNT embryos than SCNT embryos reach the blastocyst stage. Valproic acid does not increase the percentage of porcine-rhesus monkey iSCNT embryos that reach the blastocyst stage. The mechanisms underling nuclear reprogramming and epigenetic modifications in iSCNT need to be investigated further.

  16. Production of Monomeric Aromatic Compounds from Oil Palm Empty Fruit Bunch Fiber Lignin by Chemical and Enzymatic Methods

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    Pei-Ling Tang

    2015-01-01

    Full Text Available In this study, oil palm empty fruit bunch (OPEFBF was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen and enzymatic [cutinase versus manganese peroxidase (MnP] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt. and reaction time (30, 90, and 180 minutes on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17±49.44 ppm hydroxybenzoic acid, 5.67±0.25 ppm p-hydroxybenzaldehyde, 25.57±1.64 ppm vanillic acid, 168.68±23.23 ppm vanillin, 75.44±6.71 ppm syringic acid, 815.26±41.77 ppm syringaldehyde, 15.21±2.19 ppm p-coumaric acid, and 44.75±3.40 ppm ferulic acid, among the tested methods. High sodium hydroxide concentration (10% wt. was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid. Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g−1 lignin at pH 8 and 55°C for 24 hours, about 642.83±14.45 ppm hydroxybenzoic acid, 70.19±3.31 ppm syringaldehyde, 22.80±1.04 ppm vanillin, 27.06±1.20 ppm p-coumaric acid, and 50.19±2.23 ppm ferulic acid were produced.

  17. Development and characterization of mouse monoclonal antibodies against monomeric dengue virus non-structural glycoprotein 1 (NS1).

    Science.gov (United States)

    Gelanew, Tesfaye; Poole-Smith, B Katherine; Hunsperger, Elizabeth

    2015-09-15

    Dengue virus (DENV) nonstructural-1 (NS1) glycoprotein is useful for diagnosis of DENV infections in the first 8 days of illness with any of the four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4). However, NS1 diagnostics are less sensitive for secondary DENV infections so the utility of NS1 diagnostics in dengue endemic countries where there is predominantly secondary infections is being questioned. Heat-mediated immunecomplex dissociation (ICD) prior to testing serum samples can significantly improve NS1 test sensitivity in secondary infections but requires monoclonal antibodies (MAbs) reactive to heat-denatured NS1. In order to incorporate a simple heat-mediated ICD step, a crucial step was to develop new MAbs with high affinity and specificity to heat-denatured DENV NS1 protein. In the present study, six new MAbs were isolated from BALB/c mice immunized with recombinant monomeric NS1 of DENV-1 and DENV-2. Characterization using three different methods: indirect ELISA, fixed cell ELISA and western blot revealed that all six MAbs are serotype-cross-reactive and capable of recognizing dimeric and hexameric isoforms as well as heat-denatured NS1 from all four DENV serotypes. No cross-reactivity to NS1 of West Nile virus and Yellow fever virus was observed on western blot and indirect ELISA. Five of the six MAbs mapped to the DENV NS1 region of 105-119 amino acids. The remaining MAb mapped to DENV NS1 region of 25-39 amino acids. These two NS1 regions were found to be highly conserved among all four DENV serotypes by sequences analysis and database comparison. These MAbs were used to develop an NS1 capture ELISA and tested using a small panel of clinical specimens. The results from the NS1 capture ELISA indicated at least a three-fold increase in NS1 antigen detection in heat-denatured samples compared to untreated specimens. Furthermore, artificial immunecomplexed results also demonstrated the binding efficiency of these MAbs to heat denatured NS1. Taken together

  18. Synthesis, physical-chemical characterisation and biological evaluation of novel 2-amido-3-hydroxypyridin-4(1H)-ones: Iron chelators with the potential for treating Alzheimer's disease.

    Science.gov (United States)

    Gaeta, Alessandra; Molina-Holgado, Francisco; Kong, Xiao L; Salvage, Sarah; Fakih, Sarah; Francis, Paul T; Williams, Robert J; Hider, Robert C

    2011-02-01

    A novel class of 2-amido-3-hydroxypyridin-4-one iron chelators is described. These compounds have been designed to behave as suitable molecular probes which will improve our knowledge of the role of iron in neurodegenerative conditions. Neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson disease (PD), can be considered as diverse pathological conditions sharing critical metabolic processes such as protein aggregation and oxidative stress. Interestingly, both these metabolic alterations seem to be associated with the involvement of metal ions, including iron. Iron chelation is therefore a potential therapeutic approach. The physico-chemical (pK(a), pFe(3+) and logP) and biological properties (inhibition of iron-containing enzymes) of these chelators have been investigated in order to obtain a suitable profile for the treatment of neurodegenerative conditions. Studies with neuronal cell cultures confirm that the new iron chelators are neuroprotective against β-amyloid-induced toxicity.

  19. Influência do ácido giberélico na degradação do amido durante o amadurecimento da banana Influence of gibberellic acid in the starch breakdown during banana ripening

    Directory of Open Access Journals (Sweden)

    Maria Rosecler Miranda Rossetto

    2004-03-01

    Full Text Available O ácido giberélico (GA3 tem sido estudado com particular interesse na pós-colheita, pois melhora a qualidade e retarda a senescência dos frutos através de um complexo mecanismo de sinalização, interligado à atividade de enzimas responsáveis pelo processo do amadurecimento. Este hormônio vegetal, quando aplicado exogenamente, desempenha um papel importante no atraso da atividade de enzimas de parede celular, na síntese de carotenóides, degradação da clorofila e, em mangas, o GA3 diminuiu a atividade de amilases e peroxidases. A banana, fruto climatérico, tem como principal fonte de energia o amido. Este polissacarídeo é reduzido durante o climatério de teores que variam de 12 a 20%, dependendo da cultivar de banana, a menos de 1%, e o teor de sacarose pode aumentar até 12 vezes quando a fruta está amadurecida. No metabolismo de hidrólise do amido, as amilases parecem desempenhar um papel fundamental no início desta degradação, pois acredita-se que só endoamilases são capazes de atacar grânulos inteiros, fornecendo substrato para atuação de outras enzimas até a formação de açúcares. O objetivo deste trabalho foi avaliar o efeito da infiltração de giberelina A3 em fatias de banana no amadurecimento e degradação do amido. Observou-se que o fitohormônio não interferiu no climatério respiratório, porém atrasou a degradação do amido e o acúmulo de açúcares solúveis em pelo menos dois dias e o pico de atividade amilásica também foi atrasado.The gibberellic acid (GA3 has been studied with particular interest in the posharvest, therefore it improves the quality and it delay the senescence of the fruits through a complex mechanism of signaling, linked to the activity of responsible enzymes for the process of the ripening. This phytohormone, when applied exogenous, it plays an important role in the delay of the activity of enzymes, especially of the cellular wall, in the synthesis of carotene, degradation

  20. Viscosidade extensional e em cisalhamento de suspensões acidificadas de amido de amaranto e caseinato de sódio Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions

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    Angela Maria Gozzo

    2009-09-01

    Full Text Available Foram avaliadas as viscosidades extensional e em cisalhamento de suspensões acidificadas de amido de amaranto-caseinato de sódio. Sistemas mistos de amido de amaranto-caseinato de sódio acidificados com glucona-delta-lactona (GDL foram estudados por ensaios reológicos em compressão biaxial e cisalhamento. Os efeitos da velocidade de acidificação (lenta e rápida e pH final (neutro e no ponto isoelétrico da caseína foram avaliados considerando as interações entre os biopolímeros e sua consequente influência nos parâmetros reológicos. Todas as amostras apresentaram comportamento pseudoplástico, no entanto, a adição de caseinato de sódio nas suspensões de amido, em pH neutro, promoveu um efeito negativo sobre a viscosidade aparente. Amostras acidificadas apresentaram um aumento na complexidade do sistema devido à formação da rede de amido e caseína, observando que a força necessária para o escoamento foi sempre maior para as amostras contendo concentrações maiores de caseinato. Isso mostra que a agregação e gelificação da proteína promovidas pela acidificação, impediram a microsseparação de fases. Esta rede foi mais forte em sistemas gelificados lentamente, devido à formação de uma rede de proteína mais organizada. Apesar da técnica de compressão biaxial imperfeita ser limitada para avaliação de determinados sistemas, neste estudo, mostrou ser um modo prático e eficiente de se mensurar o comportamento reológico.Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions were evaluated. Mixed systems of amaranth starch-sodium caseinate acidified with glucone-delta-lactone (GDL were studied using rheological measurements under biaxial compression and shear. The effects of the acidification rate (slow and fast and final pH (neutral and isoelectric point of casein were evaluated considering the interactions between biopolymers and their influence on the rheological parameters

  1. ENZYMATIC DETERMINATION OF STARCH IN DOCE DE LEITE USING DIALYSIS DETERMINAÇÃO ENZIMÁTICA DE AMIDO EM DOCE DE LEITE COM USO DE DIÁLISE

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    Ivo Motim DEMIATE

    2001-12-01

    Full Text Available The importance of starch for the food industry makes it necessary to develop new, fast, economic and accurate methodologies for its quantification. In the present paper starch hydrolysis using commercial enzymes of industrial grade are studied aiming to develop an easy and cheap analysis, available to a greater number of industries and technicians. The proposed method is simple, divided in a first step where soluble sugars are eliminated from the samples by using dialysis, followed by starch hydrolysis of the retained fraction with a thermoresistent bacterial alfa-amylase (Termamyl 120L® and an amyloglucosidase (AMG 300L®. The hydrolysis conditions were those suggested by the enzyme producer. After the hydrolysis step the material was dialysed again for the extraction of glucose that was quantified by the glucose-oxidase colorimetric reactant. The results allowed the construction of calibration equations for starch determination on the analyzed samples. These samples were produced on a laboratory scale and native and acid-modified corn starches were added in known concentrations. By considering the final dilutions employed for glucose determination on the samples, it was possible to confirm that they were identical to that of the glucose-oxidase reactant calibration.A ampla utilização de amido pelas indústrias de alimentos faz com que haja necessidade de desenvolvimento de novas metodologias, mais rápidas, econômicas e precisas para a sua quantificação. Conforme proposto neste trabalho, a hidrólise utilizando enzimas comercias de uso industrial pode vir a agilizar e baratear os custos da análise em laboratórios e indústrias, com resultados confiáveis. A metodologia proposta é simples envolvendo, em uma primeira etapa a eliminação dos açúcares solúveis das amostras por diálise seguida da hidrólise, do material retido com uma alfa-amilase bacteriana termorresistente (Termamyl 120L® e uma amiloglucosidade (AMG 300L®. A hidr

  2. The amide C-N bond of isatins as the directing group and the internal oxidant in Ru-catalyzed C-H activation and annulation reactions: access to 8-amido isocoumarins.

    Science.gov (United States)

    Kaishap, Partha Pratim; Sarma, Bipul; Gogoi, Sanjib

    2016-07-28

    The N-O, N-N and O-O bonds are the frequently used internally oxidative directing groups used in various redox-neutral coupling reactions. The sole use of the C-N bond as the oxidizing directing group was reported recently by Li X. and co-workers for the Rh(iii)-catalyzed C-H activation of phenacyl ammonium salts. Herein, we report the use of the amide C-N bond of isatins as the oxidizing directing group for the Ru(ii)-catalyzed redox-neutral C-H activation and annulation reactions with alkynes which afford 8-amido isocoumarins. The reaction also features excellent regioselectivity with alkyl aryl substituted alkynes.

  3. PHYSICAL AND PHYSICOCHEMICAL CHARACTERIZATION OF Hedychium coronarium RHIZOMES AND STARCH CARACTERIZAÇÃO FÍSICA E FÍSICO-QUÍMICA DE RIZOMAS E AMIDO DO LÍRIO-DO-BREJO (Hedychium coronarium

    Directory of Open Access Journals (Sweden)

    Diego Palmiro Ramirez ascheri

    2010-05-01

    ,serif;">O presente trabalho teve por objetivos avaliar a composição de rizomas do lírio-do-bejo (Hedychium coronarium e isolar e caracterizar seu amido, por meio de análises físicas e físico-químicas. A composição química dos grânulos de amido isolados dos rizomas também foi determinada, bem como o formato, tamanho, distribuição de tamanho de partícula por difração a laser, viscosidade de pasta em analisador rápido de viscosidade, poder de inchamento, índice de solubilidade em água, propriedade térmica por calorimetria diferencial de varredura e cristalinidade por difração de raios X. Observou-se que os rizomas apresentaram elevado teor de água e baixos teores de matéria graxa, carboidratos, cinzas, proteínas e fibras. Os rizomas de lírio-do-brejo apresentam-se inadequados para produção de amido, devido ao baixo teor de matéria seca (17,3%, com 21,97% de amido, bem como fibras longas e látex, que dificultam a extração do amido. O amido extraído apresentou pureza de 99,2%, com 37,2% de amilose. Os grânulos de amido apresentaram forma poliédrica irregular e tamanho médio de 38,2 ?m. Constatou-se que a estrutura cristalina dos grânulos de amido é do tipo A, a qual é mantida por intensas forças associativas internas, que reduzem sua solubilidade em água. A temperatura de gelatinização do amido ocorre entre 73,1ºC e 78,7°C. O perfil de viscosidade de pasta do amido mostrou alta estabilidade a 95°C e grande tendência à retrogradação, sendo indicado para uso em indústria de adesivos e alimentos.

    Caracterización fisicoquímica de almidones de tubérculos cultivados en Yucatán, México Caracterização físico-química de amidos de tubérculos cultivados em Yucatán, México

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    Marilyn Hernández-Medina

    2008-09-01

    Full Text Available Se realizó la evaluación de las propiedades fisicoquímicas y funcionales de almidones de tubérculos: makal (Xanthosoma yucatanensis, camote (Ipomea batata, yuca (Manihot esculenta Crantz y sagú (Marantha arundinacea. El tamaño promedio de los gránulos de almidón varió de 10,6 a 16,5 µm. La amilosa fue de 23,6, 19,6, 17,0 y 22,7%, para el makal, camote, yuca y sagú. Las temperaturas de gelatinización fueron de 78,4, 61,3, 65,2 y 74,9 °C, respectivamente. El almidón de yuca fue el que presentó mayor poder de hinchamiento y solubilidad. La viscosidad máxima fue para el almidón de yuca. El almidón de camote presentó la mayor claridad de gel (51,8% y el de makal, la menor (10,9%. El almidón de yuca fue el más elástico (36,2%. Los almidones de makal y de sagú pueden ser utilizados en productos que requieren altas temperaturas de procesamiento. Los almidones de camote y de yuca pueden ser incluidos en sistemas alimenticios como espesantes, estabilizantes y gelificantes en alimentos refrigerados y congelados.Foram avaliadas as propriedades físico-químicas e funcionais de amidos dos seguintes tubérculos: makal (Xanthosoma yucatanensis, batata-doce (Ipomea batata, mandioca (Manihot esculenta Crantz e araruta (Marantha arundinacea. O tamanho médio dos grânulos de amido variou de 10,6 a 16,5 µm. A amilose foi de 23,6, 19,6, 17,0 e 22,7%, para makal, batata-doce, mandioca e araruta. As temperaturas de gelatinização foram de 78,4, 61,3, 65,2 e 74,9 °C, respectivamente. O amido de mandioca foi o que apresentou maior poder de inchamento e solubilidade. A viscosidade máxima foi para o amido de mandioca. O amido de batata-doce apresentou a maior claridade de gel (51,8% e o amido de makal, a menor (10,9%. O amido de mandioca foi o mais elástico (36,2%. Os amidos de makal e de araruta podem ser utilizados em produtos que requerem altas temperaturas de processamento. Os amidos de batata-doce e de mandioca podem ser incluídos em

  4. Método de determinação de açúcares aldeídicos a partir do amido de bambu Method for aldehydic sugar determination from bamboo starch

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    Anísio Azzini

    1985-01-01

    Full Text Available O amido de bambu foi hidrolisado sob diferentes condições de sacarificação, empregando-se soluções de ácido clorídrico com diversas concentrações (0,5; 1,0; 1,5; 2,5; 5,0 e 10,0% base v/v e tempos de reação (30, 60 e 90 minutos. Os resultados mostraram que o amido de bambu foi completamente hidrolisado, após 60 minutos de reação sob refluxo em solução ácida com 2,5% de concentração. Os açúcares aldeídicos obtidos foram determinados por um método volumétrico, baseado na oxidação dos açúcares por uma solução de iodo (KI/I2. Este método analítico é simples, de fácil execução e apresentou bom nível de exatidão avaliado através de curva-padrão.Bamboo starch was hydrolized under different saccharification conditions using hydrochloric acid at several concentrations (0.5;1.5; 2.5; 5.0 and 10.0% and reaction time (30; 60 and 90 min. The results showed that bamboo starch was completely hydrolized by hydrochloric acid solution (2.5 % after 60 min of reaction. The aldehydic sugars obtained, were determined by a volumetric method based on sugar oxidation by a KI/I2 solution and tritation of the I2 excess with a solution of Na2S2O3. The method is rapid, easy, precise, and can be used routinely for determination of aldehydic sugars (glucose after saccharification.

  5. Unique fluorophores in the dimeric archaeal histones hMfB and hPyA1 reveal the impact of nonnative structure in a monomeric kinetic intermediate.

    Science.gov (United States)

    Stump, Matthew R; Gloss, Lisa M

    2008-02-01

    Homodimeric archaeal histones and heterodimeric eukaryotic histones share a conserved structure but fold through different kinetic mechanisms, with a correlation between faster folding/association rates and the population of kinetic intermediates. Wild-type hMfB (from Methanothermus fervidus) has no intrinsic fluorophores; Met35, which is Tyr in hyperthermophilic archaeal histones such as hPyA1 (from Pyrococcus strain GB-3A), was mutated to Tyr and Trp. Two Tyr-to-Trp mutants of hPyA1 were also characterized. All fluorophores were introduced into the long, central alpha-helix of the histone fold. Far-UV circular dichroism (CD) indicated that the fluorophores did not significantly alter the helical content of the histones. The equilibrium unfolding transitions of the histone variants were two-state, reversible processes, with DeltaG degrees (H2O) values within 1 kcal/mol of the wild-type dimers. The hPyA1 Trp variants fold by two-state kinetic mechanisms like wild-type hPyA1, but with increased folding and unfolding rates, suggesting that the mutated residues (Tyr-32 and Tyr-36) contribute to transition state structure. Like wild-type hMfB, M35Y and M35W hMfB fold by a three-state mechanism, with a stopped-flow CD burst-phase monomeric intermediate. The M35 mutants populate monomeric intermediates with increased secondary structure and stability but exhibit decreased folding rates; this suggests that nonnative interactions occur from burial of the hydrophobic Tyr and Trp residues in this kinetic intermediate. These results implicate the long central helix as a key component of the structure in the kinetic monomeric intermediates of hMfB as well as the dimerization transition state in the folding of hPyA1.

  6. Trapping of Vibrio cholerae cytolysin in the membrane-bound monomeric state blocks membrane insertion and functional pore formation by the toxin.

    Science.gov (United States)

    Rai, Anand Kumar; Chattopadhyay, Kausik

    2014-06-13

    Vibrio cholerae cytolysin (VCC) is a potent membrane-damaging cytolytic toxin that belongs to the family of β barrel pore-forming protein toxins. VCC induces lysis of its target eukaryotic cells by forming transmembrane oligomeric β barrel pores. The mechanism of membrane pore formation by VCC follows the overall scheme of the archetypical β barrel pore-forming protein toxin mode of action, in which the water-soluble monomeric form of the toxin first binds to the target cell membrane, then assembles into a prepore oligomeric intermediate, and finally converts into the functional transmembrane oligomeric β barrel pore. However, there exists a vast knowledge gap in our understanding regarding the intricate details of the membrane pore formation process employed by VCC. In particular, the membrane oligomerization and membrane insertion steps of the process have only been described to a limited extent. In this study, we determined the key residues in VCC that are critical to trigger membrane oligomerization of the toxin. Alteration of such key residues traps the toxin in its membrane-bound monomeric state and abrogates subsequent oligomerization, membrane insertion, and functional transmembrane pore-formation events. The results obtained from our study also suggest that the membrane insertion of VCC depends critically on the oligomerization process and that it cannot be initiated in the membrane-bound monomeric form of the toxin. In sum, our study, for the first time, dissects membrane binding from the subsequent oligomerization and membrane insertion steps and, thus, defines the exact sequence of events in the membrane pore formation process by VCC.

  7. The impact of single nucleotide polymorphism in monomeric alpha-amylase inhibitor genes from wild emmer wheat, primarily from Israel and Golan

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    Yan Ze-Hong

    2010-06-01

    Full Text Available Abstract Background Various enzyme inhibitors act on key insect gut digestive hydrolases, including alpha-amylases and proteinases. Alpha-amylase inhibitors have been widely investigated for their possible use in strengthening a plant's defense against insects that are highly dependent on starch as an energy source. We attempted to unravel the diversity of monomeric alpha-amylase inhibitor genes of Israeli and Golan Heights' wild emmer wheat with different ecological factors (e.g., geography, water, and temperature. Population methods that analyze the nature and frequency of allele diversity within a species and the codon analysis method (comparing patterns of synonymous and non-synonymous changes in protein coding sequences were used to detect natural selection. Results Three hundred and forty-eight sequences encoding monomeric alpha-amylase inhibitors (WMAI were obtained from 14 populations of wild emmer wheat. The frequency of SNPs in WMAI genes was 1 out of 16.3 bases, where 28 SNPs were detected in the coding sequence. The results of purifying and the positive selection hypothesis (p Conclusions Great diversity at the WMAI locus, both between and within populations, was detected in the populations of wild emmer wheat. It was revealed that WMAI were naturally selected for across populations by a ratio of dN/dS as expected. Ecological factors, singly or in combination, explained a significant proportion of the variations in the SNPs. A sharp genetic divergence over very short geographic distances compared to a small genetic divergence between large geographic distances also suggested that the SNPs were subjected to natural selection, and ecological factors had an important evolutionary role in polymorphisms at this locus. According to population and codon analysis, these results suggested that monomeric alpha-amylase inhibitors are adaptively selected under different environmental conditions.

  8. Directed evolution of a monomeric, bright and photostable version of Clavularia cyan fluorescent protein: structural characterization and applications in fluorescence imaging

    Energy Technology Data Exchange (ETDEWEB)

    Al, Hui-wang; Henderson, J. Nathan; Remington, S. James; Campbell, Robert E. (Alberta); (Oregon)

    2008-05-07

    The arsenal of engineered variants of the GFP [green FP (fluorescent protein)] from Aequorea jellyfish provides researchers with a powerful set of tools for use in biochemical and cell biology research. The recent discovery of diverse FPs in Anthozoa coral species has provided protein engineers with an abundance of alternative progenitor FPs from which improved variants that complement or supersede existing Aequorea GFP variants could be derived. Here, we report the engineering of the first monomeric version of the tetrameric CFP (cyan FP) cFP484 from Clavularia coral. Starting from a designed synthetic gene library with mammalian codon preferences, we identified dimeric cFP484 variants with fluorescent brightness significantly greater than the wild-type protein. Following incorporation of dimer-breaking mutations and extensive directed evolution with selection for blue-shifted emission, high fluorescent brightness and photostability, we arrived at an optimized variant that we have named mTFP1 [monomeric TFP1 (teal FP 1)]. The new mTFP1 is one of the brightest and most photostable FPs reported to date. In addition, the fluorescence is insensitive to physiologically relevant pH changes and the fluorescence lifetime decay is best fitted as a single exponential. The 1.19 {angstrom} crystal structure (1 {angstrom}=0.1 nm) of mTFP1 confirms the monomeric structure and reveals an unusually distorted chromophore conformation. As we experimentally demonstrate, the high quantum yield of mTFP1 (0.85) makes it particularly suitable as a replacement for ECFP (enhanced CFP) or Cerulean as a FRET (fluorescence resonance energy transfer) donor to either a yellow or orange FP acceptor.

  9. Efeito do teor de água, amilose, amilopectina e grau de gelatinização no crescimento do biscoito de amido de mandioca obtido por fermentação natural Effect of the water, amylose, amylopectin contents and the degree of gelatinization on the sour cassava (Manihot sculenta, K. starch biscuit growth

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    Claudio Ernani MENDES DA SILVA

    1998-04-01

    Full Text Available O amido de mandioca, assim como o amido de araruta, modificado por fermentação natural, quando formulado com água, sal e gordura vegetal hidrogenada para produzir o biscoito de "polvilho azedo", tem a propriedade de se expandir durante a cocção, como se nessa formulação existisse um agente aerante. O produto final obtido, tem uma estrutura alveolar, crocante e de baixa densidade. Pouco se conhece a respeito do mecanismo que envolve essa expansão e sobre os fatores que interferem na mesma. No presente trabalho, investigamos a influência do teor de água, o efeito da pré-gelatinização do amido fermentado e a adição de amilose e de amilopectina no crescimento do biscoito. O tempo de formação do biscoito, demonstrou ser altamente dependente do teor de água presente na sua formulação. A gelatinização total do amido modificado por fermentação, parece destruir completamente suas propriedades de expansão, pois não foi observado crescimento do biscoito com uma formulação padrão contendo apenas amido totalmente gelatinizado. Biscoitos formulados com amilose ou amilopectina em substituição ao amido fermentado, apresentaram baixo grau de expansão quando comparados ao padrão.The sour cassava starch (and also ararut starch is unique in the ability to produce a biscuit (made of water, shortening and salt that oven springs during baking as if it has in its formulation a leavening agent. The final product has an alveolar structure, it is crocant and low density. The fators that control its growth are unknown. In this paper were investigated the effects of the water, pregelatinized sour cassava starch, amylose and amylopectin contents on the biscuit growth. It has been showed that the time of formation of the biscuit structure depends on the water formulation content. The complete gelatinization of this starch seems to destroy its unique property to grow with heat as if it had a leavening agent in its formulation. Biscuits made of

  10. Antioxidant effects of phenolic rye (Secale cereale L.) extracts, monomeric hydroxycinnamates, and ferulic acid dehydrodimers on human low-density lipoproteins

    DEFF Research Database (Denmark)

    Andreasen, Mette Findal; Landbo, A K; Christensen, L P

    2001-01-01

    Dietary antioxidants that protect low-density lipoprotein (LDL) from oxidation may help to prevent atherosclerosis and coronary heart disease. The antioxidant activities of purified monomeric and dimeric hydroxycinnamates and of phenolic extracts from rye (whole grain, bran, and flour) were...... investigated using an in vitro copper-catalyzed human LDL oxidation assay. The most abundant ferulic acid dehydrodimer (diFA) found in rye, 8-O-4-diFA, was a slightly better antioxidant than ferulic acid and p-coumaric acid. The antioxidant activity of the 8-5-diFA was comparable to that of ferulic acid...

  11. Antioxidant effects of phenolic rye (Secale cereale L.) extracts, monomeric hydroxycinnamates, and ferulic acid dehydrodimers on human low-density lipoproteins

    DEFF Research Database (Denmark)

    Andreasen, M.F.; Landbo, Anne-Katrine Regel; Christensen, L.P.

    2001-01-01

    Dietary antioxidants that protect low-density lipoprotein (LDL) from oxidation may help to prevent atherosclerosis and coronary heart disease. The antioxidant activities of purified monomeric and dimeric hydroxycinnamates and of phenolic extracts from rye (whole grain, bran, and flour) were...... investigated using an in vitro copper-catalyzed human LDL oxidation assay. The most abundant ferulic acid dehydrodimer (diFA) found in rye, 8-O-4- diFA, was a slightly better antioxidant than ferulic acid and p-coumaric acid. The antioxidant activity of the 8-5-diFA was comparable to that of ferulic acid...

  12. Primary fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, S; Jensen, L T; Foldager, M

    1990-01-01

    Serum concentrations of procollagen type III aminoterminal peptide have previously been reported to be low in some patients with primary fibromyalgia and the aim of this study was to determine if such patients differ clinically from primary fibromyalgia patients with normal levels of procollagen...... type III aminoterminal peptide. Subjective symptoms, tender points and dynamic muscle strength in 45 women with primary fibromyalgia were related to serum concentrations of procollagen type III aminoterminal peptide. Patients with low serum concentrations of procollagen type III aminoterminal peptide...... concentrations of procollagen type III aminoterminal peptide of primary fibromyalgia patients are connected to the disease impact....

  13. Absorption spectrum of monomeric pseudoisocyanine: A new perspective and its implications for formation and spectral response of J-aggregates in solution and in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Guelen, Demet [Physics Department, Middle East Technical University (METU), 06531 Ankara (Turkey)], E-mail: dgul@metu.edu.tr; Ozcelik, Serdar [Chemistry Department, Izmir Institute of Technology, Urla 35430, Izmir (Turkey)

    2008-05-15

    We argued against the current spectral assignment for absorption spectrum of monomeric PIC which is widely accepted since the pioneering works of Scheibe and Jelley [G. Scheibe, Angew. Chem. 49 (1936) 563; E.E. Jelly, Nature 138 (1936) 1009]. A new spectrum is presented along with its conceptual basis. The hypothesized spectrum attributes the previous 0-0 ({approx}525 nm) and 0-1 ({approx}490 nm) assignments, respectively, to intermediates acting as the precursor of J-aggregates and to the 0-0 transition of monomeric PIC and brings the spectrum in accord with the seemingly universal spectral fingerprint of cyanines. The hypothesis is used to analyze and interpret the temperature dependence of the UV-vis absorption of PIC aggregates in saline aqueous solution by incorporating the J-band simulations within frenkel exciton formalism. Its implications for aggregate formation kinetics are given on the basis of current spectroscopic evidence. The hypothesis readily answers several long-standing questions: Why compared to many other cyanines at least an order of magnitude higher dye concentration is needed to form J-aggregates of PIC? Why are there no precursors, since aggregation is expected to be a consecutive process? A large number of observations on steady-state and time-resolved spectral properties, and aggregation kinetics in solution/thin films are likely to find reasonable explanations within this hypothesis.

  14. Useful Method for the Preparation of Low-Coordinate Nickel(I) Complexes via Transformations of the Ni(I) Bis(amido) Complex K{Ni[N(SiMe3)(2,6- (i) Pr2-C6H3)]2}

    Science.gov (United States)

    Lipschutz, Michael I; Tilley, T Don

    2014-10-13

    A convenient method of preparing two- and three-coordinate Ni(I) complexes of the form L-Ni(I)-X (L = P (t) Bu3, P (i) Pr3, DPPE, NHC; X = -N(SiMe3)(2,6- (i) Pr-C6H3), -O(2,6- (t) Bu2-4-Me-C6H2)) is reported. Protonation of the easily prepared anionic Ni(I) bis(amido) complex K{Ni[N(SiMe3)(2,6- (i) Pr-C6H3)]2} in the presence of an appropriate L-type ligand results in loss of HN(SiMe3)(2,6- (i) Pr-C6H3) and trapping of the resulting neutral Ni(I)-amido fragment to yield neutral, paramagnetic, two- and three-coordinate Ni(I) complexes. Protonation of these neutral amido complexes by the bulky phenol HO(2,6- (t) Bu2-4-Me-C6H2) results in loss of the second amido moiety and trapping by the resulting phenoxide to yield Ni(I)-O(2,6- (t) Bu2-4-Me-C6H2) complexes. The hapticity of the phenoxide ligand is influenced by the π-accepting ability of the L-type ligand. Where L = P (t) Bu3, a poor π-acceptor, the phenoxide acts as a π-acceptor and adopts a η(5)-bonding mode through dearomatization of the phenyl ring. When L = NHC, a competent π-acceptor, the phenoxide acts as a π-donor, adopting a η(1)-bonding mode through the O atom. The modular nature of this synthetic strategy allows variation of both the L- and X-type ligands of the complex in a stepwise fashion and should be extendable to a wide variety of ligand types for new Ni(I) complexes.

  15. Efeito do teor de amido danificado na produção de biscoitos tipo semi-duros Effect of damaged starch in the production of sugar-snap cookie type

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Gutkoski

    2007-03-01

    Full Text Available O trabalho objetivou estudar a danificação do amido de farinha de trigo por moagem e o seu efeito na produção de biscoitos tipo semi-duros. Amostras de trigo dos cultivares BR 23, BRS Angico e Rubi, com características diferentes quanto à dureza foram moídas em moinho de rolos através de uma passagem pelo conjunto de quebra; quebra mais três reduções na umidade 16% e quebra mais três reduções na umidade 12%. Neste tratamento, a moagem foi complementada pelo emprego de moinho de bolas. Nas farinhas, foram realizadas análises físicas, químicas, reológicas e funcionais, utilizando delineamento casualizado em planejamento fatorial completo 3 x 3, totalizando nove tratamentos. Os resultados foram analisados estatisticamente e, nos modelos significativos, as médias comparadas entre si pelo teste de Tukey a 5% de probabilidade de erro. Os resultados rendimento de quebra, proteína bruta, amido danificado, força geral do glúten (W x 10-4J e relação tenacidade/extensibilidade (P/L indicam que a farinha do cultivar BRS Angico apresentou melhores características para a produção de biscoitos seguido de BR 23 e Rubi. O teor de amido danificado produzido durante a moagem dos trigos influencia nas propriedades funcionais dos biscoitos apresentando melhor resultado aqueles obtidos a partir de uma passagem pelo conjunto de quebra.The objective of this research was to study the damage starch of wheat flour which occurred in the milling process and its effect in the production of sugar-snap cookie type. Samples of the wheat by cultivars BR 23, BRS Angico and Rubi, with different hardness were milled in a roller-mill through a passage for the break system; a break and three reductions in the 16% of moisture, a break and three reductions in the 12% of moisture. In this treatment, the milling was complemented using a ball-mill. The flours were analyzed with respect to physical, chemistry, rheology and functional characteristics, using a 3 x

  16. Lecitina, silicone e amido na adubação foliar de couve (Brassica oleracea L. Lecithin, silicon and starch in the foliar feeding on collard green (Brassica oleracea L.

    Directory of Open Access Journals (Sweden)

    Rosmany Aires Cunha Martins

    2010-12-01

    Full Text Available Objetivou-se, no presente trabalho, avaliar os efeitos que a lecitina, amido e silicone possam ter na eficiência da adubação foliar, utilizando-se sais e quelatos como fonte de micronutrientes. Para isso foi realizado um experimento em que avaliaram-se os efeitos da adição de diferentes adjuvantes em relação à absorção e translocação de zinco e manganês na forma de sais e quelatos. O delineamento utilizado foi o inteiramente casualizado, com seis repetições, com quatro fatores em estudo e dois níveis cada, perfazendo um fatorial 2x2x2x2, totalizando dezesseis tratamentos. Além dos tratamentos, foi adicionada testemunha como tratamento adicional, perfazendo, assim, um total de 102 parcelas. Cada parcela foi constituída por um vaso, contendo uma planta de couve-manteiga (Brassica oleracea L. var. acephala DC.. Os tratamentos constaram de combinações entre 2 fontes (sulfato e quelato e de presença ou ausência de três substâncias na calda de pulverização: lecitina de soja desengordurada, um siliconado comercial e gel de amido de mandioca. A determinação dos efeitos constituiu-se na análise do teor de zinco e manganês nas folhas novas 30 dias após a pulverização. A adição de lecitina aumentou a absorção do sulfato de zinco ao passo que o produto siliconado aumentou a absorção do zinco quelatizado. Tanto a lecitina quanto o produto siliconado, quando adicionados à calda de pulverização, aumentaram o teor de manganês. O gel de amido não aumentou a absorção de nenhum micronutriente.The objective of the present work was to evaluate the effect of lecithin, starch and silicon may have in the efficiency of foliar feeding, using salts and chelates as source of nutrients. The experiment was carried out under greenhouse condition at Univerdidade Federal de Goiás (Jataí unit - GO, set in a completely randomized design, with six replications, four factors in study and two levels each, making a 2x2x2x2 factorial

  17. Influência da adição de amido de mandioca na biodegradação da blenda polimérica PHBV/Ecoflex®

    Directory of Open Access Journals (Sweden)

    Marilia Pellicano

    2009-01-01

    Full Text Available Os polímeros derivados do petróleo são amplamente utilizados devido à sua versatilidade, propriedades mecânicas e custo relativamente baixo, mas causam impacto ambiental como conseqüência da grande quantidade de resíduos lançados ao meio ambiente. Os problemas gerados pelo descarte de plásticos de origem petroquímica impulsionam o desenvolvimento, produção e aplicação de polímeros biodegradáveis. Entretanto, estes polímeros apresentam custo elevado e propriedades nem sempre satisfatórias. Portanto, neste trabalho fez-se um estudo do composto polimérico formado por poli(hidroxibutirato-co-valerato - PHBV (Biocycle®, poli(butilenoadipato-tereftalato - Ecoflex® e amido de mandioca. Este composto polimérico foi avaliado quanto ao índice de fluidez (MFI, Microscopia Eletrônica de Varredura (MEV, ensaios mecânicos de tração e de impacto, e ensaio de biodegradação. Os resultados obtidos nas diversas técnicas indicaram: que o amido de mandioca atua como uma carga inerte; que existe uma baixa adesão matriz/carga no composto polimérico e que a adição de amido aumenta a taxa de biodegradação do composto, em relação aos polímeros puros. No estudo realizado foi possível obter um material para aplicação no curto prazo, com um custo viável, propriedades físico-mecânicas adequadas e excelente taxa de biodegradação.Plastic materials produced from petrochemicals are widely used due to their versatility, mechanical properties and low cost, but they cause environmental impact as a consequence of the accumulation of great amount of these conventional synthetic polymers. The problems caused by the waste disposal of these plastics have motivated the development, production and application of biodegradable polymers; however these polymers have high costs and non-suitable mechanical and physical properties. Therefore, a study of polymeric compounds made of poly(hydroxyburyrate-co-valerate - PHBV, poly

  18. Fibra solúvel e amido como fontes de carboidratos para terminação de novilhos em confinamento Soluble fiber and starch as carbohydrates sources for finishing feedlot steers

    Directory of Open Access Journals (Sweden)

    Cristian Faturi

    2006-10-01

    Full Text Available Avaliou-se o efeito da utilização de duas fontes de carboidratos solúveis, amido ou fibra solúvel em detergente neutro, associadas a dois níveis de FDN, sobre o desempenho de novilhos de corte em confinamento na fase de terminação. Foram confinados 24 novilhos ½ Angus x ½ Nelore, com idade inicial de 18 meses e peso de 329 ± 24 kg. As quatro dietas foram calculadas para fornecer nível de PB suficiente para ganho diário de 1,4 kg. As dietas foram constituídas de 40% de silagem de milho e 60% de concentrado (grão de milho, polpa cítrica e casca de soja, além de minerais e uréia, arranjados de forma a promover nível alto de amido associado a dois níveis de FDN (48 e 39% ou nível alto de fibra solúvel associado aos dois níveis de FDN. Observou-se que os animais alimentados com a dieta com maior nível de polpa cítrica (45%, com baixos teores de fibra solúvel e FDN, apresentaram consumo reduzido e, conseqüentemente, baixo ganho de peso e pior conversão alimentar. Entre as dietas com maior nível de FDN, verificou-se que os animais alimentados com fibra solúvel apresentaram o melhor ganho de peso (1,435 vs 1,262 kg/dia e a melhor conversão alimentar (7,494 vs 8,651, mas não diferiram daqueles do tratamento com amido e baixo teor de FDN. Os resultados demonstraram que é possível alterar o desempenho animal manipulando a fonte e a concentração dos carboidratos solúveis.The effects of starch or neutral detergent soluble fiber associated with two dietary levels of NDF on performance of finishing feedlot beef steers were evaluated in this trial. Twenty-four crossbred ½ Angus x ½ Nellore steers averaging 18 months of age and 329 ± 24 kg of body weight at the beginning of the trial were used. All four diets were balanced to supply the crude protein requirements for a daily weight gain of approximately 1.4 kg. Diets were composed (dry matter basis by 40% of corn silage and 60% of concentrate containing corn grain, citrus

  19. Primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Parulekar, A.H.

    Photosynthetic production in the oceans in relation to light, nutrients and mixing processes is discussed. Primary productivity in the estuarine region is reported to be high in comparison to coastal and oceanic waters. Upwelling phenomenon...

  1. Primary hyperparathyroidism

    OpenAIRE

    Madkhali, Tarıq; Alhefdhi, Amal; Chen, Herbert; Elfenbein, Dawn

    2016-01-01

    Primary hyperparathyroidism is a common endocrine disorder caused by overactivation of parathyroid glands resulting in excessive release of parathyroid hormone. The resultant hypercalcemia leads to a myriad of symptoms. Primary hyperparathyroidism may increase a patient’s morbidity and even mortality if left untreated. During the last few decades, disease presentation has shifted from the classic presentation of severe bone and kidney manifestations to most patients now being diagnosed on rou...

  2. Investigation of monomeric and oligomeric wine stilbenoids in red wines by ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Moss, Ryan; Mao, Qinyong; Taylor, Dennis; Saucier, Cédric

    2013-08-30

    Stilbenoids are secondary plant metabolites responsible for the protection of multiple plant species including grape vine from bacterial and fungal infection. Red wine has been shown to be a major source of these compounds in the human diet, where they display an array of health benefits. Providing a more complete profile of the stilbenoids present in red wine, this study detects 41 stilbenoid compounds, 23 of which have never before been detected in red wine. Red wine extracts were scanned using an ultra-high-performance liquid chromatograph coupled to a hybrid quadrupole time-of-flight mass analyzer. Multiple targeted MS/MS precursor ion scan experiments were performed using electrospray ionization operated in negative mode. Precursor ion masses were scanned for the monomeric and oligomeric stilbenoids, as well as modifications such as O-glycosylation, methoxylation and oxidation products of these compounds. Accurate mass precursor and characteristic product ions afforded partial structural elucidation and assignment of these compounds. A total of 41 (both known and novel) stilbenoids were detected in extracted red wine. In addition to the well-known monomeric stilbenes, several resveratrol-resveratrol homodimers (m/z 453.1344), resveratrol-piceatannol heterodimers (m/z 469.1293) and piceatannol-piceatannol homodimers (m/z 485.1236) were detected. Modified dimers of resveratrol including O-glycosylated (m/z 615.1872), methoxylated (m/z 485.1606) and oxidized (m/z 471.1449) dimers were also detected. Multiple trimers of resveratrol (m/z 679.1978) were detected for the first time in red wine, as well as some known and some novel stilbenoid tetramers (m/z 905.2604). In summary, 41 stilbenoids were detected in red wine, 23 for the first time. Both monomeric and oligomeric stilbenoids were partially identified and assigned by their accurate mass precursor ions and characteristic stilbenoid fragmentation patterns. Knowledge gained from these experiments contributes to

  3. Evaluating the effect of wood ultrastructural changes from mechanical treatment on kinetics of monomeric sugars and chemicals production in acid bisulfite treatment.

    Science.gov (United States)

    Liu, Yalan; Wang, Jinwu; Wolcott, Michael P

    2017-02-01

    Currently, various chemical-mechanical treatments were widely used in biofuel production to achieve high total sugar yields. However, the interaction between two treatments was scarcely investigated. In this study, we employed a ball milling process to create ultrastructural changes for Douglas-fir (Pseudotsuga menziesii) micronized wood powders. The 0, 30, and 60min ball milled wood powders resulted in a crystallinity index of 0.41, 0.21, and 0.10 respectively. It was found that the ultrastructural changes accelerate monomeric sugars production without influencing the yield of sugar degradation products. The optimal acid bisulfite treatment time was substantially decreased from 120min to 40min as the cellulose crystallinity decreased. Meanwhile, total sugar yield increased from 65% to 92% and had a linear relation with a decrease of the cellulose crystallinity.

  4. Corrosion inhibition of aluminum with a series of aniline monomeric surfactants and their analog polymers in 0.5 M HCl solution

    Directory of Open Access Journals (Sweden)

    M.M. El-Deeb

    2015-07-01

    Full Text Available The inhibition effect of 3-(12-sodiumsulfonate dodecyloxy aniline monomeric surfactant (MC12 and its analog polymer Poly 3-(dodecyloxy sulfonic acid aniline (PC12 on the corrosion of aluminum in 0.5 M HCl solution was investigated using weight loss and potentiodynamic polarization techniques. The presence of these two compounds in 0.5 M HCl inhibits the corrosion of aluminum without modifying the mechanism of corrosion process. It was found that these inhibitors act as mixed-type inhibitors with anodic predominance as well as the inhibition efficiency increases with increasing inhibitor concentration, but decreases with raising temperature. Langmuir and Frumkin adsorption isotherms fit well with the experimental data. Thermodynamic functions for both dissolution and adsorption processes were determined. The obtained results from weight loss and potentiodynamic polarization techniques are in good agreement with contact angle measurements.

  5. Plant small monomeric G-proteins (RAC/ROPs) of barley are common elements of susceptibility to fungal leaf pathogens, cell expansion and stomata development.

    Science.gov (United States)

    Pathuri, Indira Priyadarshini; Eichmann, Ruth; Hückelhoven, Ralph

    2009-02-01

    Small monomeric RAC/ROP GTPases act as molecular switches in signal transduction processes of plant development and stress responses. They emerged as crucial players in plant-pathogen interactions either by supporting susceptibility or resistance. In a recent publication, we showed that constitutively activated (CA) mutants of different barley (Hordeum vulgare) RAC/ROPs regulate susceptibility to barley fungal leaf pathogens of different life style in a contrasting way. This illustrates the distinctive signalling roles of RAC/ROPs for different plant-pathogen combinations. We also reported the involvement of RAC/ROPs in plant epidermis development in a monocotyledonous plant. Here we further discuss a failure of CA HvRAC/ROP-expressing barley to normally develop stomata.

  6. PENGARUH PENGOLAHAN PANAS TERHADAP KONSENTRASI ANTOSIANIN MONOMERIK UBI JALAR UNGU (Ipomoea batatas L (Efect of Heat Processing on Monomeric Anthocyanin of Purple Sweet Potato (Ipomoea batatas L

    Directory of Open Access Journals (Sweden)

    Ai Mahmudatussa'adah

    2015-09-01

    content in PSP during heat processing of flakes. The other purpose of this reseach was to observe the order kinetics model of effect temperature and time baking on total anthocyanin monomeric of fresh PSP and rehydration PSP flakes. The experimental applied a completely randomized design with three replications. The color and amount of anthocyanin (L * = 23.38 ± 0.71, C = 9.84 ± 0.98, Hue = 12.25 ± 1.61. Total monomeric anthocyanin in fresh PSP was 1.45 ± 0.00 mg cyanidin equivalent (CyE/g dry basis (db. In general, the color and the amount of PSP anthocyanin changed during the flakes processing. Steamed PSP for 7 minutes turned its color into a bright purple (L * = 25.88 ± 0.47, C = 24.64 ± 0.25, Hue = 348.83 ± 0.33 with the amount of monomeric anthocyanin increased to 3.76 ± 0.01 CyE mg/g db. Flakes PSP was very bright purple (L * = 36.12 ± 0.11, C = 9.97 ± 0.18, Hue = 359.29 ± 0.31 and the amount of monomericanthocyanin was slightly lower than that of steamed sweet potato (3.19 ± 0.12 mg CyE / g db. Total monomeric anthocyanin of fresh PSP and rehydration flakes PSP decrease during baking time. Keywords: Color, anthocyanin, purple sweet potato, flakes, degradation kinetics   ABSTRAK Antosianin merupakan salah satu kelompok zat warna alami yang terdapat pada tanaman, seperti daun, bunga, umbi, buah atau sayur. Salah satu sumber antosianin pada tanaman adalah ubi jalar ungu (UJU yang mengandung lebih dari 98% antosianin terasilasi dari konsentrasi antosianin umbi. Warna antosianin bervariasi mulai dari merah, ungu, biru, sampai kuning. Warna dan konsentrasi antosianin dapat berubah karena pengaruh panas. Penelitian ini bertujuan untuk mempelajari perubahan warna dan konsentrasi antosianin monomerik sebagai akibat proses pengolahan dalam pembuatan  UJU. Penelitian ini mengkaji juga mengenai model kinetika reaksi pengaruh suhu dan waktu panggang terhadap konsentrasi antosianin UJU segar dan  rehidrasi. Penelitian menggunakan rancangan acak lengkap

  7. Purified monomeric ligand.MD-2 complexes reveal molecular and structural requirements for activation and antagonism of TLR4 by Gram-negative bacterial endotoxins.

    Science.gov (United States)

    Gioannini, Theresa L; Teghanemt, Athmane; Zhang, DeSheng; Esparza, Gregory; Yu, Liping; Weiss, Jerrold

    2014-08-01

    A major focus of work in our laboratory concerns the molecular mechanisms and structural bases of Gram-negative bacterial endotoxin recognition by host (e.g., human) endotoxin-recognition proteins that mediate and/or regulate activation of Toll-like receptor (TLR) 4. Here, we review studies of wild-type and variant monomeric endotoxin.MD-2 complexes first produced and characterized in our laboratories. These purified complexes have provided unique experimental reagents, revealing both quantitative and qualitative determinants of TLR4 activation and antagonism. This review is dedicated to the memory of Dr. Theresa L. Gioannini (1949-2014) who played a central role in many of the studies and discoveries that are reviewed.

  8. Optimization of ultrasound-assisted extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant (Solanum melongena L.) peel.

    Science.gov (United States)

    Dranca, Florina; Oroian, Mircea

    2016-07-01

    The present study describes the extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant peel using ultrasonic treatments and methanol and 2-propanol as extraction solvents. The extraction yields were optimized by varying the solvent concentration, ultrasonic frequency, temperature and time of ultrasonic treatment. Box-Behnken design was used to investigate the effect of process variables on the ultrasound-assisted extraction. The results showed that for TPC extraction the optimal condition were obtained with a methanol concentration of 76.6%, 33.88 kHz ultrasonic frequency, a temperature of 69.4 °C and 57.5 min extraction time. For TMA the optimal condition were the following: 54.4% methanol concentration, 37 kHz, 55.1 °C and process time of 44.85 min. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Zn-bis-glutathionate is the best co-substrate of the monomeric phytochelatin synthase from the photosynthetic heavy metal-hyperaccumulator Euglena gracilis.

    Science.gov (United States)

    García-García, Jorge D; Girard, Lourdes; Hernández, Georgina; Saavedra, Emma; Pardo, Juan P; Rodríguez-Zavala, José S; Encalada, Rusely; Reyes-Prieto, Adrián; Mendoza-Cózatl, David G; Moreno-Sánchez, Rafael

    2014-03-01

    The phytochelatin synthase from photosynthetic Euglena gracilis (EgPCS) was analyzed at the transcriptional, kinetic, functional, and phylogenetic levels. Recombinant EgPCS was a monomeric enzyme able to synthesize, in the presence of Zn(2+) or Cd(2+), phytochelatin2-phytochelatin4 (PC2-PC4) using GSH or S-methyl-GS (S-methyl-glutathione), but not γ-glutamylcysteine or PC2 as a substrate. Kinetic analysis of EgPCS firmly established a two-substrate reaction mechanism for PC2 synthesis with Km values of 14-22 mM for GSH and 1.6-2.5 μM for metal-bis-glutathionate (Me-GS2). EgPCS showed the highest Vmax and catalytic efficiency with Zn-(GS)2, and was inactivated by peroxides. The EgPCS N-terminal domain showed high similarity to that of other PCSases, in which the typical catalytic core (Cys-70, His-179 and Asp-197) was identified. In contrast, the C-terminal domain showed no similarity to other PCSases. An EgPCS mutant comprising only the N-terminal 235 amino acid residues was inactive, suggesting that the C-terminal domain is essential for activity/stability. EgPCS transcription in Euglena cells was not modified by Cd(2+), whereas its heterologous expression in ycf-1 yeast cells provided resistance to Cd(2+) stress. Phylogenetic analysis of the N-terminal domain showed that EgPCS is distant from plants and other photosynthetic organisms, suggesting that it evolved independently. Although EgPCS showed typical features of PCSases (constitutive expression; conserved N-terminal domain; kinetic mechanism), it also exhibited distinct characteristics such as preference for Zn-(GS)2 over Cd-(GS)2 as a co-substrate, a monomeric structure, and ability to solely synthesize short-chain PCs, which may be involved in conferring enhanced heavy-metal resistance.

  10. Resolution of two native monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina and the sequence of two napA genes

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Philippa J.L. [School of Chemistry, University of Sydney, NSW 2006 (Australia); McKinzie, Audra A. [School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, NSW 2006 (Australia); Codd, Rachel, E-mail: rachel.codd@sydney.edu.au [School of Chemistry, University of Sydney, NSW 2006 (Australia); School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, NSW 2006 (Australia)

    2010-07-16

    Research highlights: {yields} Two monomeric 90 kDa nitrate reductase active proteins from Shewanella gelidimarina. {yields} Sequence of napA from napEDABC-type operon and napA from NapDAGHB-type operon. {yields} Isolation of NAP as NapA or NapAB correlated with NapA P47E amino acid substitution. -- Abstract: The reduction of nitrate to nitrite in the bacterial periplasm occurs in the 90 kDa NapA subunit of the periplasmic nitrate reductase (NAP) system. Most Shewanella genomes contain two nap operons: napEDABC and napDAGHB, which is an unusual feature of this genus. Two native, monomeric, 90 kDa nitrate reductase active proteins were resolved by hydrophobic interaction chromatography from aerobic cultures of Shewanella gelidimarina replete with reduced nitrogen compounds. The 90 kDa protein obtained in higher yield was characterized as NapA by electronic absorption and electron paramagnetic resonance spectroscopies and was identified by LC/MS/MS and MALDI-TOF/TOF MS as NapA from the napEDABC-type operon. The other 90 kDa protein, which was unstable and produced in low yields, was posited as NapA from the napDAGHB-type operon. Two napA genes have been sequenced from the napEDABC-type and napDAGHB-type operons of S. gelidimarina. Native NAP from S. putrefaciens was resolved as one NapA monomer and one NapAB heterodimer. Two amino acid substitutions in NapA correlated with the isolation of NAP as a NapA monomer or a NapAB heterodimer. The resolution of native, redox-active NapA isoforms in Shewanella provides new insight into the respiratory versatility of this genus, which has implications in bioremediation and the assembly of microbial fuel cells.

  11. Salt anions promote the conversion of HypF-N into amyloid-like oligomers and modulate the structure of the oligomers and the monomeric precursor state.

    Science.gov (United States)

    Campioni, Silvia; Mannini, Benedetta; López-Alonso, Jorge P; Shalova, Irina N; Penco, Amanda; Mulvihill, Estefania; Laurents, Douglas V; Relini, Annalisa; Chiti, Fabrizio

    2012-12-07

    An understanding of the solution factors contributing to the rate of aggregation of a protein into amyloid oligomers, to the modulation of the conformational state populated prior to aggregation and to the structure/morphology of the resulting oligomers is one of the goals of present research in this field. We have studied the influence of six different salts on the conversion of the N-terminal domain of Escherichiacoli HypF (HypF-N) into amyloid-like oligomers under conditions of acidic pH. Our results show that salts having different anions (NaCl, NaClO(4), NaI, Na(2)SO(4)) accelerate oligomerization with an efficacy that follows the electroselectivity series of the anions (SO(4)(2-)≥ ClO(4)(-)>I(-)>Cl(-)). By contrast, salts with different cations (NaCl, LiCl, KCl) have similar effects. We also investigated the effect of salts on the structure of the final and initial states of HypF-N aggregation. The electroselectivity series does not apply to the effect of anions on the structure of the oligomers. By contrast, it applies to their effect on the content of secondary structure and on the exposure of hydrophobic clusters of the monomeric precursor state. The results therefore indicate that the binding of anions to the positively charged residues of HypF-N at low pH is the mechanism by which salts modulate the rate of oligomerization and the structure of the monomeric precursor state but not the structure of the resulting oligomers. Overall, the data contribute to rationalize the effect of salts on amyloid-like oligomer formation and to explain the role of charged biological macromolecules in protein aggregation processes.

  12. Influência do tratamento térmico e da acidez no comportamento reológico de amidos nativos funcionais de milho cerosos orgânicos comerciais Heat treatment and acidity influence on the rheological behavior of commercial organic waxy corn starch

    Directory of Open Access Journals (Sweden)

    Lizielle Maria Ricardo Guerreiro

    2009-06-01

    Full Text Available Os amidos são amplamente utilizados em alimentos como molhos para salada, molhos e pratos prontos. Entretanto, as propriedades funcionais de amidos nativos não resistem aos processos estressantes tais como tratamento térmico, acidez e alto cisalhamento. Os amidos podem ser modificados quimicamente neste sentido, mas não atribuem ao alimento o rótulo de "natural". Uma outra opção é obter amidos naturais resistentes às condições de estresse. O objetivo do presente trabalho foi a avaliação de dois amidos que se comercializam rotulados como nativos e orgânicos frente ao tratamento térmico e à acidez. Suspensões dos amidos nativos funcionais orgânicos (9460 e 9560, National Starch and Chemical Industrial preparadas numa concentração de 5% (peso/volume, foram acidificadas com ácido cítrico 1M ou autoclavadas a 121 °C por 30 minutos. O resultado dos tratamentos foi avaliado por microscopia óptica, pelas curvas de escoamento e pelos espectros mecânicos, obtidos por reologia estacionária e dinâmica. A acidez e o tratamento térmico aumentaram a estruturação dos géis dos amidos, que resistiram aos processos estressantes. Os géis apresentaram comportamento não newtoniano, (pseudoplástico e tixotrópico. O comportamento pode ser modelado pela equação Lei da Potência ou Herschel-Bukley. Todos os géis apresentaram comportamento viscoelástico de gel fraco que foi preservado nos diversos tratamentos.Starches are widely utilized in foodstuffs as salad dressing, sauce, and processed foods. However, the functional properties of native starches are affected by processes such as heat treatment, acidity, and high shear stress. Starches can be modified chemically in order to have characteristics required by industries, but not to attribute the food a "natural and safe" label. Another option is to obtain native starches resistant to food processing stress conditions. The objective of this paper is the evaluation of commercial

  13. Determinação da cor, imagem superficial topográfica e ângulo de contato de biofilmes de diferentes fontes de amido Determination of color, topographic superficial image and contact angle of the biofilms of different starch sources

    Directory of Open Access Journals (Sweden)

    Washington Azevêdo da Silva

    2007-02-01

    Full Text Available Atualmente, um dos problemas que acometem o meio ambiente é a poluição ocasionada pelo descarte de filmes plásticos de polímeros sintéticos sem nenhum controle. Uma das alternativas para minimizar este problema é a utilização de amido na elaboração de materiais biodegradáveis que possuem alta degradabilidade quando lançados no meio ambiente. Apesar do número crescente de trabalhos de pesquisas utilizando diferentes materiais biodegradáveis, o conhecimento das propriedades físicas de biofilmes elaborados com amido ainda é bastante reduzido. Objetivou-se com este trabalho determinar a diferença de cor, a imagem superficial topográfica por microscopia eletrônica de varredura e o ângulo de contato de biofilmes elaborados com três diferentes tipos de amido: filme de fécula de batata (FFB, filme de fécula de mandioca (FFM e filme de amido de milho (FAM com três concentrações: 1, 2 e 3% empregando-se um delineamento inteiramente casualizado com três repetições. A interação concentração e tipo de amido foi estatisticamente significativa para ângulo de contato e não significativa para a diferença de cor. A diferença de cor foi afetada pela fonte de amido e o maior valor observado para filme de fécula de mandioca. Com o aumento da concentração de amido, o ângulo de contato diminuiu para filmes de fécula de mandioca e de batata, diferentemente para os biofilmes de milho, onde esta relação foi constante.Nowadays, the pollution has considerably increased by the large amount of the non-degradable synthetic plastics that is discarded everyday in the environment. One of the alternatives that could contribute to minimize this problem would be the use of the starch as main composite in biodegradable films also called biofilms; in other words, this material is easily degradable when disposed in the environment. Despite the growing number of the scientific papers there is a lack of knowledge of the physical properties of

  14. Hidrofilicidade de filmes de amido/poli(butileno adipato co-tereftalato (Pbat adicionados de tween 80 e óleo de soja Hydrophilicity of starch and poly(butylene adipate-co-terephthalate (Pbat films containing tween 80 and soybean oil

    Directory of Open Access Journals (Sweden)

    Renata P. Herrera Brandelero

    2013-01-01

    Full Text Available A incorporação de amido ao polímero poli (butilenoadipatoco-tereftalato (PBAT através de blendas com alto teor de amido pode ser uma alternativa para obter embalagens biodegradáveis, minimizar custos e o uso de recursos não renováveis. No entanto, a adição de amido aumenta a permeabilidade ao vapor de água (PVA. A incorporação em filmes com amido de substâncias como óleos vegetais e surfactantes pode diminuir a hidrofilicidade, favorecendo as aplicações destes como embalagens. A hidrofilicidade dos filmes elaborados por blendas de amido/PBAT adicionados de óleo de soja (OS e tween 80 (TW foi avaliada considerando o efeito do OS e TW nas isotermas de sorção dos filmes, na PVA e nos coeficientes de difusão (Dw e solubilidade (β do vapor de água. Filmes com OS com ou sem TW apresentaram menor quantidade de água de sorção, sendo os filmes com menores quantidades de OS e sem TW menos hidrofílicos e menos permeáveis aos vapores de água. A adição de OS reduziu os valores de β e Dw dos filmes de amido/PBAT. O efeito foi relacionado com o aumento das porções hidrofóbicas e da compatibilidade entre o amido e PBAT na presença de OS.Incorporating starch into the poly(butylene adipate-co-terephthalate (PBAT polymer by means of blends with high starch contents is a possible option for producing biodegradable packaging using renewable resources and reducing costs. However, the addition of starch increases the water vapour permeability (WVP. The incorporation of substances as lipids and surfactants can reduce the hydrophilicity of films containing starch, favouring their use as packaging. The hydrophilicity of films produced from blends of starch/PBAT with added soybean oil (SO and tween 80 (TW was studied. The effects of these substances on the sorption isotherm, on the WVP and on the water vapour diffusion (Dw and solubility (β coefficients of the films were evaluated. The water sorption in films with SO, with or without TW

  15. Características físico-químicas de amidos modificados com permanganato de potássio/ácido lático e hipoclorito de sódio/ácido lático Physicochemical characteristics of starches modified with potassium permanganate/lactic acid and sodium hypochlorite/lactic acid

    Directory of Open Access Journals (Sweden)

    Roberto Marques Silva

    2008-03-01

    Full Text Available Amidos oxidados em elevadas concentrações produzem pastas fluidas, são estáveis à retrogradação e aplicados em indústrias de papel, têxtil e de alimentos. Esta propriedade é atribuída à presença de carboxilas, com cargas negativas e mais volumosas que as hidroxilas. Neste trabalho, amidos de batata, batata doce, mandioca, mandioquinha salsa, milho e milho ceroso foram modificados com KMnO4/ácido lático e NaOCl/ácido lático e caracterizados quanto ao teor de carboxilas, poder redutor, coloração diferencial, propriedade de expansão e propriedades viscoamilográficas, em água e tampões acetato (pH 4,0 e fosfato (pH 7,0. Amidos de milho ceroso e de mandioca modificados com KMnO4/ácido lático apresentaram elevadas expansões (25,8 e 24,1 mL.g-1, respectivamente. As pastas de amido de milho ceroso resistiram a ciclos de congelamento/descongelamento. A coloração diferencial e o teor de carboxilas não permitiram diferenciar as amostras; apenas o amido de batata reagiu com azul de metileno devido aos grupos fosfato. Quanto ao pH e acidez, as amostras apresentaram valores próximos da neutralidade, exceto o amido de milho e milho ceroso modificados com NaOCl. Amidos oxidados com KMnO4/ácido lático apresentaram picos de viscosidade inferiores aos tratados com NaOCl. Os picos de viscosidade em tampão fosfato foram inferiores aos em água e em tampão acetato.Oxidized starches produce low-viscosity pastes even in high concentrations, are stable to retrogradation and are used in the paper, textile and food industries. This property is attributed to the presence of carboxyl groups, which have negative charges and are bulkier than hydroxyls. In this work, potato, sweet potato, Peruvian carrot, cassava, corn and waxy corn starches were modified with oxidative reagents and characterized with respect to their carboxyl content, reducing power, differential dyeing, expansion power and viscographic properties, in water, acetate buffer (p

  16. Nanostructured ZnO-TiO2 thin film oxide as anode material in electrooxidation of organic pollutants. Application to the removal of dye Amido black 10B from water.

    Science.gov (United States)

    El-Kacemi, Sana; Zazou, Hicham; Oturan, Nihal; Dietze, Matthias; Hamdani, Mohamed; Es-Souni, Mohammed; Oturan, Mehmet A

    2017-01-01

    Electrochemical oxidative degradation of diazo dye Amido black 10B (AB10B) as model pollutant in water has been studied using nanostructured ZnO-TiO2 thin films deposited on graphite felt (GrF) substrate as anode. The influence of various operating parameters, namely the current intensity, the nature and concentration of catalyst, the nature of electrode materials (anode/cathode), and the adsorption of dye and ambient light were investigated. It was found that the oxidative degradation of AB10B followed pseudo first-order kinetics. The optimal operating conditions for the degradation of 0.12 mM (74 mg L(-1)) dye concentration and mineralization of its aqueous solution were determined as GrF-ZnO-TiO2 thin film anode, 100 mA current intensity, and 0.1 mM Fe(2+) (catalyst) concentration. Under these operating conditions, discoloration of AB10B solution was reached at 60 min while 6 h treatment needed for a mineralization degree of 91 %. Therefore, this study confirmed that the electrochemical process is effective for the degradation of AB10B in water using nanostructured ZnO-TiO2 thin film anodes.

  17. Amido resistente, a última geração no controle de energia e digestão saudável Resistant starch, the latest generation of energy control and healthy digestion

    Directory of Open Access Journals (Sweden)

    Karla Dellanoce Pereira

    2007-08-01

    Full Text Available Estudos clínicos demonstraram que amido resistente tem propriedades semelhantes a fibras e mostra benefícios fisiológicos em humanos, podendo resultar em prevenção de doenças. A Organização Mundial de Saúde (OMS recomenda que cerca de 55% da energia ingerida seja proveniente de carboidratos. A preocupação com o tipo de carboidrato ingerido é importante, pois há fibras, por exemplo, que devem ser ingeridas de 25-30 g/dia/pessoa, e normalmente não o são. Por ser um alimento resistente à digestão e fermentado no intestino grosso, principalmente pelas bifidobactérias, o amido resistente é um alimento prebiótico. Durante a fermentação ocorre a produção de ácidos graxos de cadeia curta, principalmente o butirato, que contribui muito para a saúde do cólon, inibindo o crescimento de células cancerígenas devido à redução do pH no intestino grosso. Além disso, contribui para a produção da energia difusa progressiva (EDP, que é a energia liberada ao longo do tempo de uma digestão lenta, e para a queda do índice glicêmico dos alimentos, proporcionando uma menor resposta glicêmica e, conseqüentemente, uma resposta insulínica mais adequada, auxiliando no tratamento da diabete, principalmente do tipo 2 e mantendo o indivíduo com sensação de saciedade por um período maior de tempo. A National Starch Food Innovation possui o Hi-Maize 260 como amido resistente que, quando comparado com as fibras convencionais, apresenta muitas vantagens. É branco e possui sabor brando, tamanho pequeno de partícula e baixa capacidade de retenção de água, praticamente não altera a textura de produtos de baixa umidade como pães, macarrão, barrinha de cereais, etc, ao contrário das fibras convencionais, o que permite formular produtos com alto teor de fibras e ainda ser rotulado como simplesmente "amido de milho". Também apresenta teor calórico reduzido e pode ser usado como agente de corpo complementar em formulações com

  18. Carbon-carbon cross-coupling reactions catalyzed by a two-coordinate nickel(II)-bis(amido) complex via observable Ni(I) , Ni(II) , and Ni(III) intermediates.

    Science.gov (United States)

    Lipschutz, Michael I; Tilley, T Don

    2014-07-01

    Recently, the development of more sustainable catalytic systems based on abundant first-row metals, especially nickel, for cross-coupling reactions has attracted significant interest. One of the key intermediates invoked in these reactions is a Ni(III) -alkyl species, but no such species that is part of a competent catalytic cycle has yet been isolated. Herein, we report a carbon-carbon cross-coupling system based on a two-coordinate Ni(II) -bis(amido) complex in which a Ni(III) -alkyl species can be isolated and fully characterized. This study details compelling experimental evidence of the role played by this Ni(III) -alkyl species as well as those of other key Ni(I) and Ni(II) intermediates. The catalytic cycle described herein is also one of the first examples of a two-coordinate complex that competently catalyzes an organic transformation, potentially leading to a new class of catalysts based on the unique ability of first-row transition metals to accommodate two-coordinate complexes.

  19. Primary Myelofibrosis

    Science.gov (United States)

    ... the blood cells. Symptoms of primary myelofibrosis include pain below the ribs on the left side and feeling very tired. ... if you have any of the following: Feeling pain or fullness below the ribs on the left side. Feeling full sooner than ...

  20. [Primary hyperaldosteronism

    NARCIS (Netherlands)

    Meiracker, A.H. van den; Deinum, J.

    2003-01-01

    Primary hyperaldosteronism (PHA), autonomic secretion of aldosterone by the adrenal gland, is rare. PHA usually results in therapy-resistant hypertension and is often but not always accompanied by hypokalaemia. Common causes of PHA are an aldosterone-producing adenoma, idiopathic aldosterone hyperse

  1. [Primary hyperaldosteronism

    NARCIS (Netherlands)

    Meiracker, A.H. van den; Deinum, J.

    2003-01-01

    Primary hyperaldosteronism (PHA), autonomic secretion of aldosterone by the adrenal gland, is rare. PHA usually results in therapy-resistant hypertension and is often but not always accompanied by hypokalaemia. Common causes of PHA are an aldosterone-producing adenoma, idiopathic aldosterone hyperse

  2. Primary Processing

    NARCIS (Netherlands)

    Mulder, W.J.; Harmsen, P.F.H.; Sanders, J.P.M.; Carre, P.; Kamm, B.; Schoenicke, P.

    2012-01-01

    Primary processing of oil-containing material involves pre-treatment processes, oil recovery processes and the extraction and valorisation of valuable compounds from waste streams. Pre-treatment processes, e.g. thermal, enzymatic, electrical and radio frequency, have an important effect on the oil r

  3. Hyperthyroidism (primary)

    DEFF Research Database (Denmark)

    Nygaard, Birte

    2010-01-01

    Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone. The main causes of hyperthyroidism are Graves' disease, toxic multinodular goitre, and toxic adenoma. About 20 times more women than men have hyperthyroidism....... METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments for primary hyperthyroidism? What are the effects of surgical treatments for primary hyperthyroidism? What are the effects of treatments for subclinical...... hyperthyroidism? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US...

  4. Hyperthyroidism (primary)

    OpenAIRE

    Nygaard, Birte

    2008-01-01

    Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone. Thyrotoxicosis is the clinical effect of high levels of thyroid hormones, whether or not the thyroid gland is the primary source.The main causes of hyperthyroidism are Graves' disease, toxic multinodular goitre, and toxic adenoma.About 20 times more women than men have hyperthyroidism.

  5. Hyperthyroidism (primary)

    OpenAIRE

    Nygaard, Birte

    2010-01-01

    Hyperthyroidism is characterised by high levels of serum thyroxine and triiodothyronine, and low levels of thyroid-stimulating hormone (TSH). Thyrotoxicosis is the clinical effect of high levels of thyroid hormones, whether or not the thyroid gland is the primary source.The main causes of hyperthyroidism are Graves' disease, toxic multinodular goitre, and toxic adenoma.About 20 times more women than men have hyperthyroidism.

  6. Efeito de fontes e formas de processamento do amido sobre o desempenho e o metabolismo do nitrogênio em vacas Holandesas em lactação Effect of starch sources and processing on performance and nitrogen metabolism in lactating Holstein cows

    Directory of Open Access Journals (Sweden)

    Alexandre Vaz Pires

    2008-08-01

    Full Text Available Avaliou-se a influência das fontes e formas de processamento do amido utilizado na dieta sobre o desempenho e o metabolismo do nitrogênio em vacas Holandesas em lactação alimentadas com cana-de-açúcar como volumoso. Utilizaram-se cinco vacas pluríparas, canuladas no rúmen e no duodeno, distribuídas em quadrado latino 5 × 5. As rações foram compostas de 40% de cana-de-açúcar e 60% de concentrado e diferiram quanto ao processamento ou à fonte principal de amido: milho moído grosso; milho moído fino; milho floculado a 310 g/L; milho floculado a 360 g/L ou raspa de mandioca. A taxa de hidrólise in vitro do amido da raspa de mandioca foi superior à obtida com as demais fontes de amido testadas. O amido do milho floculado apresentou maior taxa de hidrólise em comparação ao amido do milho moído. Os percentuais médios totais de amido hidrolisado foram de 93,5% para raspa de mandioca, 85,6% para milho floculado a 310 g/L, 83,7% para milho floculado a 360 g/L e 37,8% para milho moído. As fontes de amido e seu tipo de processamento não influenciaram o consumo de matéria seca, os teores de gordura e proteína do leite, a síntese microbiana e a concentração plasmática de glicose. A utilização da raspa de mandioca reduziu as produções diárias de gordura e proteína e a produção de leite corrigida para 3,5% de gordura, cujos valores médios foram de 0,40; 0,45 e 12,48 kg/dia; 0,68; 0,64 e 19,74 kg/dia; 0,57; 0,62 e 17,37 kg para raspa de mandioca, milho floculado e milho moído, respectivamente. A concentração de amônia ruminal foi menor quando fornecidas as rações contendo milho floculado ou raspa de mandioca, o que indica fermentação mais ativa destas fontes de amido. Apesar de apresentar maior taxa de hidrólise do amido, a raspa de mandioca alterou o metabolismo protéico dos animais ocasionando redução da síntese de proteína microbiana.The objective of this trial was to evaluate the effect of starch sources

  7. Calcitonina monomérica plasmática e hipercalcemia em pacientes portadores de neoplasia pulmonar Monomeric plasmatic calcitonin and hypercalcemia in lung cancer patients

    Directory of Open Access Journals (Sweden)

    R. Coifman

    1997-06-01

    lung cancer, and its correlation with hypercalcemia, a very common complication in these tumors. METHOD. Blood were sampled from 56 patients with malignant lung disease for the CT and ionized calcium determinations. Calcitonin was measured using a specific radioimmunoassay for the monomeric form of the molecule, in a previous silica extracted serum probe. RESULTS. We did not find elevated levels of monomeric CT in lung cancer. Only 3 patients had mild elevated levels, while in the others CT was normal or undetectable. Hypercalcemia was found in 21.4% of these patients, but only one with supranormal CT levels. CONCLUSION. Monomeric CT serum levels are normal in lung cancer, what makes the latter use an unreliable tumor marker.

  8. Primary fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Jensen, L T; Foldager, Marie Viftrup

    1990-01-01

    type III aminoterminal peptide. Subjective symptoms, tender points and dynamic muscle strength in 45 women with primary fibromyalgia were related to serum concentrations of procollagen type III aminoterminal peptide. Patients with low serum concentrations of procollagen type III aminoterminal peptide...... had more symptoms, a higher frequency of tender points and lesser quality of sleep compared to patients with normal serum concentrations of procollagen type III aminoterminal peptide (P less than 0.05). They also had a lower dynamic muscle strength (P less than 0.0005). We conclude that the serum...

  9. The Escherichia coli P and Type 1 Pilus Assembly Chaperones PapD and FimC Are Monomeric in Solution

    Energy Technology Data Exchange (ETDEWEB)

    Sarowar, Samema; Hu, Olivia J.; Werneburg, Glenn T.; Thanassi, David G.; Li, Huilin; Christie, P. J.

    2016-06-27

    ABSTRACT

    The chaperone/usher pathway is used by Gram-negative bacteria to assemble adhesive surface structures known as pili or fimbriae. Uropathogenic strains ofEscherichia coliuse this pathway to assemble P and type 1 pili, which facilitate colonization of the kidney and bladder, respectively. Pilus assembly requires a periplasmic chaperone and outer membrane protein termed the usher. The chaperone allows folding of pilus subunits and escorts the subunits to the usher for polymerization into pili and secretion to the cell surface. Based on previous structures of mutant versions of the P pilus chaperone PapD, it was suggested that the chaperone dimerizes in the periplasm as a self-capping mechanism. Such dimerization is counterintuitive because the chaperone G1 strand, important for chaperone-subunit interaction, is buried at the dimer interface. Here, we show that the wild-type PapD chaperone also forms a dimer in the crystal lattice; however, the dimer interface is different from the previously solved structures. In contrast to the crystal structures, we found that both PapD and the type 1 pilus chaperone, FimC, are monomeric in solution. Our findings indicate that pilus chaperones do not sequester their G1 β-strand by forming a dimer. Instead, the chaperones may expose their G1 strand for facile interaction with pilus subunits. We also found that the type 1 pilus adhesin, FimH, is flexible in solution while in complex with its chaperone, whereas the P pilus adhesin, PapGII, is rigid. Our study clarifies a crucial step in pilus biogenesis and reveals pilus-specific differences that may relate to biological function.

    IMPORTANCEPili are critical virulence factors for many bacterial pathogens. UropathogenicE. colirelies on P and type 1 pili assembled by the chaperone/usher pathway to

  10. Folded-back solution structure of monomeric factor H of human complement by synchrotron X-ray and neutron scattering, analytical ultracentrifugation and constrained molecular modelling.

    Science.gov (United States)

    Aslam, M; Perkins, S J

    2001-06-22

    Factor H (FH) is a regulatory cofactor for the protease factor I in the breakdown of C3b in the complement system of immune defence, and binds to heparin and other polyanionic substrates. FH is composed of 20 short consensus/complement repeat (SCR) domains, for which the overall arrangement in solution is unknown. As previous studies had shown that FH can form monomeric or dimeric structures, X-ray and neutron scattering was accordingly performed with FH in the concentration range between 0.7 and 14 mg ml(-1). The radius of gyration of FH was determined to be 11.1-11.3 nm by both methods, and the radii of gyration of the cross-section were 4.4 nm and 1.7 nm. The distance distribution function P(r) showed that the overall length of FH was 38 nm. The neutron data showed that FH was monomeric with a molecular mass of 165,000(+/-17,000) Da. Analytical ultracentrifugation data confirmed this, where sedimentation equilibrium curve fits gave a mean molecular mass of 155,000(+/-3,000) Da. Sedimentation velocity experiments using the g*(s) derivative method showed that FH was monodisperse and had a sedimentation coefficient of 5.3(+/-0.1) S. In order to construct a full model of FH for scattering curve and sedimentation coefficient fits, homology models were constructed for 17 of the 20 SCR domains using knowledge of the NMR structures for FH SCR-5, SCR-15 and SCR-16, and vaccinia coat protein SCR-3 and SCR-4. Molecular dynamics simulations were used to generate a large conformational library for each of the 19 SCR-SCR linker peptides. Peptides from these libraries were combined with the 20 SCR structures in order to generate stereochemically complete models for the FH structure. Using an automated constrained fit procedure, the analysis of 16,752 possible FH models showed that only those models in which the 20 SCR domains were bent back upon themselves were able to account for the scattering and sedimentation data. The best-fit models showed that FH had an overall length

  11. Electrophysiological effects of kainic acid on vasopressin-enhanced green fluorescent protein and oxytocin-monomeric red fluorescent protein 1 neurones isolated from the supraoptic nucleus in transgenic rats.

    Science.gov (United States)

    Ohkubo, J; Ohbuchi, T; Yoshimura, M; Maruyama, T; Ishikura, T; Matsuura, T; Suzuki, H; Ueta, Y

    2014-01-01

    The supraoptic nucleus (SON) contains two types of magnocellular neurosecretory cells: arginine vasopressin (AVP)-producing and oxytocin (OXT)-producing cells. We recently generated and characterised two transgenic rat lines: one expressing an AVP-enhanced green fluorescent protein (eGFP) and the other expressing an OXT-monomeric red fluorescent protein 1 (mRFP1). These transgenic rats enable the visualisation of AVP or OXT neurones in the SON. In the present study, we compared the electrophysiological responses of AVP-eGFP and OXT-mRFP1 neurones to glutamic acid in SON primary cultures. Glutamate mediates fast synaptic transmission through three classes of ionotrophic receptors: the NMDA, AMPA and kainate receptors. We investigated the contributions of the three classes of ionotrophic receptors in glutamate-induced currents. Three different antagonists were used, each predominantly selective for one of the classes of ionotrophic receptor. Next, we focused on the kainate receptors (KARs). We examined the electrophysiological effects of kainic acid (KA) on AVP-eGFP and OXT-mRFP1 neurones. In current clamp mode, KA induced depolarisation and increased firing rates. These KA-induced responses were inhibited by the non-NMDA ionotrophic receptor antagonist 6-cyano-7-nitroquinoxaline-2,3(1H4H)-dione in both AVP-eGFP and OXT-mRFP1 neurones. In voltage clamp mode, the application of KA evoked inward currents in a dose-dependent manner. The KA-induced currents were significantly larger in OXT-mRFP1 neurones than in AVP-eGFP neurones. This significant difference in KA-induced currents was abolished by the GluK1-containing KAR antagonist UBP302. At high concentrations (250-500 μm), the specific GluK1-containing KAR agonist (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl) propanoic acid (ATPA) induced significantly larger currents in OXT-mRFP1 neurones than in AVP-eGFP neurones. Furthermore, the difference between the AVP-eGFP and OXT-mRFP1 neurones in the ATPA currents

  12. Structural proteins of the primary cell wall: extraction, purification, and analysis.

    Science.gov (United States)

    Lamport, Derek T A; Tan, Li; Kieliszewski, Marcia J

    2011-01-01

    Structural proteins of the primary cell wall present unusual but interesting problems for structural biologists in particular and plant biologists in general. As structure is the key to function; then the biochemical isolation of these glycoproteins for further study is paramount. Here, we detail the "classical" method for isolating soluble extensin monomers by elution of monomeric precursors to network extensin from tissue cultures. We also outline an additional approach involving genetic engineering that can potentially yield the complete genomic range of extensins and other hydroxyproline-rich glycoprotein (HRGPs) currently underutilized for biotechnology.

  13. Atividade microbiana cecal e contribuição nutricional da cecotrofia em coelhos alimentados com rações contendo diferentes fontes de fibra e níveis de amido Caecal microbial activity and caecotrophy nutritional contribution in rabbits fed diets with different starch levels and fiber sources

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    Alex Martins Varela de Arruda

    2003-08-01

    Full Text Available Objetivou-se neste estudo a avaliação da atividade microbiana cecal e a contribuição nutricional da cecotrofia em coelhos alimentados com rações contendo diferentes níveis de amido (22 a 32% em média mediante a inclusão de milho grão e diferentes fontes de fibra (feno de alfafa ou casca de soja, em esquema fatorial 2x2. No primeiro experimento, 40 coelhos alojados em gaiolas de engorda individuais, em delineamento inteiramente casualizado e alimentados à vontade dos 45 aos 85 dias de idade, foram abatidos para coleta dos conteúdos ileais e cecais. A concentração de ácidos graxos voláteis foi influenciada pela interação entre tratamentos, sendo 93,82 mmol/l para ração de maior nível de amido com casca de soja e 80,03 mmol/l para ração de menor nível de amido com feno de alfafa. No segundo experimento, 40 coelhos aos 65 dias de idade, alojados em gaiolas de engorda individuais, em delineamento inteiramente casualizado, foram alimentados à vontade por 10 dias, e receberam colares de madeira para permitir a coleta total de cecotrofos. Houve influência da interação entre tratamentos sobre os teores de proteína e energia dos cecotrofos, sendo de 29,66% e 4204,87 kcal/kg para ração contendo maiores níveis de amido e casca de soja e de 27,98% e 4080,46 kcal/kg para ração contendo menores níveis de amido e feno de alfafa. As rações de alto amido ou com casca de soja propiciaram maior enriquecimento do conteúdo cecal e melhor aporte nutricional para os coelhos.The objective of this study was to evaluate the caecal microbial activity and caecotrophy nutritional contribution in rabbits fed diets with differents starch levels (22 or 32% on average from a high or low inclusion of corn grain and differents fiber sources (alfalfa hay or soybean hulls, in a 2x2 factorial design. In the first experiment, 40 rabbits were individually housed in fattening cages within entirely randomized design, and fed ad libitum from 45 to 85

  14. Digestibilidade e atividade enzimática intestinal de coelhos em crescimento alimentados com diferentes fontes de amido processadas ou não por extrusão Digestibility and intestinal enzymatic activity of growing rabbits fed different sources of starch processed or not by extrusion

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    Luciana Kazue Otutumi

    2005-04-01

    Full Text Available Foram conduzidos dois experimentos para avaliar a digestibilidade do amido e a atividade específica das enzimas amilase (ATAM e maltase (ATMAL, em duas porções do intestino delgado (jejuno e íleo, em coelhos com idades iniciais de 28 e 49 dias, alimentados com quatro fontes de amido (milho, sorgo, triticale e mandioca, processados ou não por extrusão. Em cada experimento, foram utilizados 64 coelhos da raça Nova Zelândia Branco, distribuídos em um delineamento inteiramente casualizado com oito tratamentos e oito repetições. Ao final do período experimental, os animais foram abatidos para retirada de amostra do conteúdo do jejuno e íleo, além da raspagem da mucosa do jejuno, para determinação da ATAM e ATMAL. O processamento melhorou o coeficiente de digestibilidade (CD do amido do milho e do sorgo. Entre as fontes não-extrusadas, os maiores CD do amido foram apresentados pelo triticale e pela mandioca. A ATAM da parede do jejuno foi maior aos 60 dias. A ATMAL no conteúdo do jejuno e do íleo foi maior aos 37 dias. As diferentes fontes de amido diferiram entre si quanto à ATMAL e ATAM do conteúdo do jejuno e do íleo. A ATMAL foi maior no jejuno. Maiores ATAM do conteúdo do jejuno ocorreu aos 60 dias para os animais que receberam milho extrusado e sorgo. A ATAM aos 37 dias foi maior no íleo em comparação com o jejuno para os animais que receberam milho e sorgo. O processamento foi efetivo para o milho e sorgo, porém, todas as fontes, processadas ou não, apresentaram bom CD do amido, podendo ser utilizadas na alimentação de coelhos.Two experiments were carried out to study the digestibility of starch and the specific activity of amylase (ACAMY and maltase (ACMAL enzymes in two portions of small intestine (jejunum and ileum, in rabbits with initial ages of 28 and 49 days, fed with four sources of starch (corn, sorghum, triticale and cassava processed or not by extrusion. Sixty-four White New Zealand rabbits were used in

  15. Efeito de fibras vegetais nas propriedades de compósitos biodegradáveis de amido de mandioca produzidos via extrusão Effects of vegetal fibers on properties of cassava starch biodegradable composites produced by extrusion

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    Flávia Debiagi

    2010-12-01

    Full Text Available A preocupação com o volume de lixo tem gerado interesse no desenvolvimento de embalagens biodegradáveis capazes de substituir, ao menos em parte, os plásticos convencionais sintéticos, como é o caso das embalagens de poliestireno expandido (Isopor. Ojvetivou-se,neste trabalho caracterizar, quanto ao índice de expansão (IE, densidade, índice de absorção em água (IAA, índice de solubilidade em água (ISA e cor (coordenadas L*, a* e b*, compósitos biodegradáveis expandidos produzidos via extrusão, a partir da mistura de amido de mandioca, glicerol (plastificante e dois tipos de fibras vegetais. Os compósitos foram preparados em extrusora mono-rosca, com três diferentes teores de fibras de aveia ou de cana-de-açúcar (0, 5 e 10 g/100 g amido, dois teores de umidade (18 e 26% e teor fixo de glicerol (20g/100 g sólidos. A adição das fibras não afetou significativamente o IE, a densidade e o IAA, porém diminuiu o ISA dos materiais, o que é uma vantagem, favorecendo a utilização das fibras no reforço dos compósitos. A adição de fibras levou ao escurecimento das amostras, com decréscimo da luminosidade (L* e, ainda, ao aumento nos valores dos parâmetros de cor a* e b*. Este estudo é passo fundamental para produção em escala industrial dos compósitos, que necessitam de condições de processo que forneçam resultados reprodutíveis de expansão e capacidade de absorção e solubilidade em água, propriedades de grande importância nesses produtos.The concern with the volume of waste has generated interest in the development of biodegradable packaging able to replace, at least in part, the conventional synthetic plastics, such as packs of expanded polystyrene (Isopor. This study aimed to characterize the expansion index, density, the water absorption index (WAI, water solubility index (WSI and color (coordinates L*, a* and b* of expanded biodegradable composites produced by extrusion, from the mixture cassava starch

  16. Revestimento ativo de amido na conservação pós-colheita de pera Williams minimamente processada Starch-based edible coating on extending shelf life of fresh-cut pear

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    Diego Alvarenga Botrel

    2010-08-01

    Full Text Available A pera é uma das frutas de clima temperado mais consumidas no Brasil, no entanto sua conservação é limitada devido ao seu escurecimento quando sofre danos ou tratamentos físicos. Os revestimentos comestíveis interagem favoravelmente com o alimento, aumentando sua vida de prateleira. Este trabalho objetivou avaliar a ação de revestimento de amido adicionado de lactato de cálcio e L-cisteína na inibição do escurecimento enzimático, na redução do crescimento de psicrotrófilos e enterobactérias e na manutenção da textura. As peras fatiadas foram cobertas com revestimentos comestíveis à base de amido incorporados com cisteína e lactato de cálcio, exceto o controle - sem revestimento (C. Os tratamentos foram: apenas revestimento (T1; 2,0% lactato de cálcio e 1,0% L-cisteína (T2 e 2,0% lactato de cálcio e 1,5% L-cisteína (T3. As amostragens foram feitas nos tempos zero, dois, quatro e seis dias. As amostras foram mantidas sob refrigeração (7°C±2°C. As peras submetidas aos tratamentos T2 e T3 apresentaram-se significativamente mais firmes (PPear is one of the most consumed temperate fruits in Brazil; however their conservation is limited due to browning when it suffers injuries or physical treatments. The edibles coating interact with the food positively extending its shelf life. This research aimed to evaluate the action of starch edible coating incorporated with calcium lactate and L-cysteine on enzymatic browning inhibition, on psychrotrophs and enterobacteriaceae growing reduction and on firmness maintenance. The sliced pears were coated with starch edible coating incorporated with L-cysteine and calcium lactate, except control, without coating (C. The treatment were: only coating (T1; 2,0% calcium lactate and 1,0% L-cysteine (T2; 2,0% calcium lactate and 1,5% L-cysteine (T3. The samples were taken at 0, 2, 4 and 6 days. Pears were keeped under refrigeration (7°C±2°C. Pears submitted to treatments T2 and T3 show

  17. Capacidade tamponante, pH e consistência das fezes em equinos submetidos à sobrecarga dietética com amido Buffer capacity, pH and faeces consistency in horses submitted to dietetic starch overload

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    Tiago Marques dos Santos

    2009-09-01

    Full Text Available Este trabalho teve como objetivo avaliar a capacidade tamponante (CT, o pH e a consistência das fezes em equinos submetidos à sobrecarga dietética com amido. Seis equinos adultos foram submetidos à sobrecarga com infusão gástrica de 17,6g de amido kg-1 de peso corporal através de sonda nasogástrica. Amostras fecais foram coletadas, antes e quatro, oito, 12, 16, 20, 24, 28, 32 e 36 horas pós-sobrecarga, e imediatamente submetidas à avaliação do pH, da CT e da consistência. Os resultados de pH foram comparados pelo teste t de student (P0,05 no pH fecal ao longo de 36 horas pós-sobrecarga, com valores médios variando de 6,09 a 4,46. A partir do modelo pH = 6,083 - 0,003t - 0,001t² (R² = 0,634, houve decréscimo de 0,004 no pH fecal a cada hora, de 0,028 a cada quatro horas e de 1,404 ao final de 36 horas após a sobrecarga, respectivamente. Além do pH, houve redução (PThis study aimed to evaluate buffer capacity (BC, pH and faeces consistency of horses submitted to dietetic starch overload. Six crossbreed mature horses were submitted to starch overload with gastric infusion of 17.6g starch kg-1 body weight through nasogastric tube. Faecal samples were collected, before and at 4, 8, 12, 16, 20, 24, 28, 32 and 36 hours post-overload, and immediately submitted to evaluation of pH, BC and consistency. The pH data were compared by t student test (P0.05, with means values varying from 6.09 to 4.46. Based on the model pH = 6.083 - 0.003t - 0.001t² (R² = 0.634, faecal pH decreased 0.004 per hour, 0.028 to each four hours and 1.404 at 36 hours after overload, respectively. As pH, faeces BC decreased (P<0.05 in function of the time after overload. Positive relationship was observed (r = 0.65; P<0.0001 between pH and BC of faeces. All horses presented normal consistency faeces (score 3 until eight hours after overload, following by reduction (P<0.05 up to 36 hours. Results demonstrated that starch overload reduce faecal consistency

  18. Valor nutritivo de rações compostas de fontes de amido e de nitrogênio com alta e baixa degradabilidade ruminal Nutritive value of diets composed by starch and nitrogen sources with high and low ruminal degradability

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    Lúcia Maria Zeoula

    1999-01-01

    Full Text Available O objetivo deste estudo foi avaliar o consumo, o coeficiente de digestibilidade aparente (CDA, o balanço de nitrogênio, o pH e a concentração de nitrogênio amoniacal no líquido ruminal de ovinos. Os animais foram alimentados com rações compostas de concentrados com diferentes degradabilidade ruminal das frações amido e nitrogênio das seguintes fontes: amido (AM de alta (triticale e baixa (milho degradabilidade ruminal combinada com fontes de nitrogênio (N de alta (farelo de canola + uréia e baixa (farelo de algodão + farinha de carne e ossos degradabilidade ruminal. Dezesseis carneiros Suffok castrados com peso médio de 37 kg PV foram usados para estimar os CDA por intermédio do método de coleta total de fezes e urina. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 2 x 2, com quatro repetições por tratamento. Na avaliação do pH e nitrogênio amoniacal, o delineamento usado foi de parcelas subdivididas, sendo os tratamentos considerados como parcelas e os tempos de amostragem como subparcelas. Maiores consumos de matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN foram observados nos animais alimentados com as rações que continham fontes de N de baixa degradabilidade ruminal. Maiores CDA da MS, PB e energia bruta foram observados para as rações com fontes de N de alta degradabilidade ruminal e do AM, para as rações com fontes de AM e N de alta degradabilidade ruminal. A fonte de N de baixa degradabilidade ruminal propiciou o maior valor de pH e a mais baixa concentração de amônia ruminal.The objective of this study was to evaluate the intake, apparent digestibility coefficient (ADC, nitrogen balance, pH and nitrogen ammonia concentration (N-NH3 in the ruminal fluid of sheep. The animals were fed diets composed by concentrates with different ruminal degradability of the fractions starch and protein from the used sources: starch with high (triticale and low (corn

  19. Efeito das fontes de amido e nitrogênio de diferentes degradabilidades ruminais.1. Digestibilidades parcial e total Effect of starch and nitrogen sources of different ruminal degradability. 1. Total and partial digestibility

    Directory of Open Access Journals (Sweden)

    Fábio Luiz Fregadolli

    2001-06-01

    Full Text Available Avaliaram-se as digestibilidades parcial e total de rações combinando fontes de amido (AM de alta (casca de mandioca desidratada e baixa (milho degradabilidade ruminal, com fontes de nitrogênio (N de alta (levedura e baixa (farelo de algodão + farinha de carne e ossos degradabilidade ruminal, em arranjo fatorial 2x2. Foram utilizados quatro novilhos da raça Holandesa (334 kg, portadores de cânula ruminal e duodenal, distribuídos em delineamento quadrado latino 4x4. O óxido crômico foi utilizado como indicador de fluxo de matéria seca. Houve interação das fontes de AM e N sobre o coeficiente de digestibilidade aparente (CDA da proteína bruta (PB e fibra em detergente neutro (FDN. As rações com milho e levedura e as com casca de mandioca e farelo de algodão + farinha de carne e ossos apresentaram maior CDA para PB do que as rações com milho e farelo de algodão + farinha de carne e osso e com as casca de mandioca e levedura. A ração com amido e N de alta degradabilidade ruminal (casca de mandioca e levedura propiciou menor valor sobre o CDA da FDN do que as demais rações, que não diferiram entre si. A digestão ruminal da FDN foi maior quando a fonte de AM foi o milho, comparada àquela contendo casca de mandioca. A maior digestão do AM foi para as rações com casca de mandioca, comparada às rações com milho, em todos os segmentos do trato digestivo. Observaram-se valores negativos para a digestão ruminal da PB para as rações experimentais. A fonte de N influenciou a digestão ruminal e intestinal da energia bruta. A maior a digestão ruminal ocorreu nas rações com levedura e a maior digestão intestinal, nas rações com farelo de algodão + farinha de carne e ossos.Total and partial digestibility of diets combining the starch sources of high degradability (dried cassava hulls and low degradability (corn, with nitrogen sources of high (yeast and low (cottonseed meal and meat and bone meal degradability, in a 2 x 2

  20. Synergistic action of starch and honey against Candida albicans in correlation with diastase number Ação sinergística de amido e mel sobre Cândida albicans em relação ao índice de diastase

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    Laïd Boukraa

    2008-03-01

    Full Text Available To evaluate the synergistic action of starch on the antifungal activity of honey, a comparative method of adding honey with and without starch to culture media was used. Candida albicans has been used to determine the minimum inhibitory concentration (MIC of five varieties of honey. In a second step, lower concentrations of honey than the MIC were incubated with a set of concentrations of starch added to media to determine the minimum synergistic inhibitory concentration (MSIC. The MIC for the five varieties of honey without starch against C. albicans ranged between 40% and 45% (v/v. When starch was incubated with honey and then added to media, a MIC drop has been noticed with each variety. It ranged between 7% and 25%. A negative correlation has been established between the MIC drop and the diastase number (DN.Para avaliar a ação sinergística do amido na atividade antifúngica do mel, utilizou-se um método comparativo de adição ou não de mel ao meio de cultura com e sem amido. Cândida albicans foi utilizada para determinar a Concentração Inibitória Mínima (CIM de cinco variedades de mel. Na etapa seguinte, determinou-se a Concentração Inibitória Sinergística Mínima (CISM empregando-se méis em concentração abaixo da CIM incubados com amido em diferentes concentrações.

  1. Efeito da concentração de ácido lático sobre a propriedade de expansão em amidos modificados fotoquimicamente Effect of lactic acid concentration on expansion property of photochemically modified starches

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    Ana Carolina Dal Bianco Garcia

    2005-06-01

    Full Text Available Uma característica valorizada pelo setor alimentício é a propriedade de expansão dos grânulos de amido. Com este trabalho, teve-se por objetivo avaliar o efeito da concentração de ácido lático durante tratamento de modificação fotoquímica das féculas de batata-doce (Ipomoea batatas, biri (Canna edulis, mandioca (Manihot esculenta e taioba (Xanthosoma sagittifolium. Pelos resultados obtidos neste experimento, nas condições em que este foi realizado, conclui-se que a concentração de ácido lático interferiu na propriedade de expansão das féculas de batata-doce, mandioca e taioba e não apresentou efeito na fécula de biri, devendo ser ajustado para cada tipo de fécula a ser modificada. Os índices de expansão obtidos nas diferentes féculas foram considerados baixos, quando comparados aos índices obtidos para fécula de mandioca modificada.The expansion property of starch granules is of great importance to the food industries. The effect of lactic acid concentration during photochemical treatment of sweet potato (Ipomoea batatas, edible canna (Canna edulis, cassava (Manihot esculenta and cocoyam (Xanthosoma sagittifolium starches was evaluated. The results showed that the acid concentration influenced the expansion property of sweet potato, cassava and cocoyam starches, but no differences were observed in edible canna starch, so that the acid concentration must be adjusted for each starch. The expansion ranges observed in all starches were lower that in modified cassava starch.

  2. Propriedades termodinâmicas de adsorção de água do amido de rizomas do lírio-do-brejo (Hedychium coronarium Thermodynamic properties of water adsortion of the starch of rhizome of swamp lily (Hedychium coronarium

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    Diego Palmiro Ramirez Ascheri

    2009-06-01

    Full Text Available Determinaram-se as propriedades termodinâmicas (entalpia diferencial, entropia diferencial, entalpia integral e entropia integral do amido de rizomas do lírio-do-brejo (Hedychium coronarium por meio de isotermas de adsorção de água. As isotermas foram determinadas em atividades de água no intervalo de 0,11 a 0,84, sob temperaturas que variaram de 30 a 50 °C. A Equação de GAB, que se ajustou bem às isotermas experimentais, foi utilizada para estimar as propriedades termodinâmicas de adsorção. As isotermas apresentaram ligeira inversão, indicando a precença de amido danificado. A entalpia diferencial e a entropia diferencial aumentaram com a diminuição da umidade de equilíbrio e correlacionaram entre si confirmando a compensação química linear. Um modelo exponencial do tipo Y = b.e(a/Xe descreveu adequadamente a dependência destas propriedades diferenciais ao teor de umidade de equilíbrio. A entalpia integral e a entropia integral aumentaram continuamente com o teor de umidade de equil��brio, porém com valores negativos para a entropia integral. Estas propriedades termodinâmicas de adsorção de água demonstraram que o amido extraído dos rizomas do lírio-do-brejo possui baixa higrocopicidade apesar da ocorrência de grânulos de amido danificados.Thermodynamic properties where determined (differential enthalpy, of differential entropy, integral enthalpy, and integral entropy of the starch of rhizomes of swamp lily through water adsorption isotherms. The isotherms were determined in water activities in the range of 0.11 to 0.84, in temperatures ranging from 30 to 50 °C. The GAB equation which fits well to the experimental isotherms was used to estimate the properties of thermodynamic adsorption. The slight reversal of the isotherms indicates damaged starch. The enthalpy and entropy differential gap increased with the decrease in moisture and correlated to each other confirming the chemical linear compensation. An

  3. EFEITO DA EMBALAGEM COM SACOS DE POLIETILENO NO COMPORTAMENTO DO AMIDO NA POLPA DE BANANA DO CULTIVAR PRATA (Musa sp. NO PERÍODO DE CONSERVAÇÃO E MATURAÇÃO EFFECT OF POLYETHYLENE PACKING BAGS ON THE STARCH BEHAVIOR IN THE CONSERVATION MATURATION PERIOD OF BANANA PULP CULTIVAR “PRATA” (Musa sp.

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    Lincoln F. Zica

    2007-09-01

    Full Text Available

    Neste trabalho estudou-se o comportamento do amido da polpa de banana do cultivar “Prata" (Musa sp., sob os seguintes tratamentos: Testemunha, sem embalagem; Plástico perfurado; Plástico perfurado, contendo absorvente; Plástico sem perfuração; Plástico, sem perfuração, contendo absorvente. As bananas tratadas, foram acondicionadas em uma câmara com temperatura constante de 22 ± 1°C e umidade relativa de 90 ± 3%. Uma vez por dia era feita a ventilação da câmara. De dois em dois dias, retiravam-se amostras de cada tratamento e faziam-se as análises. Com auxílio das análises estatísticas dos dados obtidos conclui-se que: a. A embalagem com polietileno atrasa o início da queda do amido, mas não impede a sua transformação. b. a percentagem de amido na polpa, permanece constante até que, em dado momento, que varia com os tratamentos, inicia a sua variação. c. O uso de absorvente de etileno dentro da embalagem plástica, sem perfuração, atrasa mais o início da queda do amido, mas não impede que os frutos se tornem imprestáveis para o consumo.

    In this experiment, the behavior of starch in the pulp of banana Prata (Musa sp., was studied under the following treatments: bananas without packing, perforated plastic, perforated plastic with an absorbent, unperforated plastic, unperforated plastic containing an absorbent. The treated bananas, were shelved at 22 ± 1°C and a relative humidity of 90 ± 3%. Every 2 days, samples of each treatment were collected and analysis were made. With the help of statistical analyses of the data, the following conclusions were reached: a. The packaging with polyethylene delays the starch breakdown, but does not impede its transformation. b. The percentage of starch of the pulp remains constant until a given moment, which varies with each treatment, when its

  4. Primary hyperparathyroidism.

    Science.gov (United States)

    Muñoz-Torres, Manuel; García-Martín, Antonia

    2017-10-06

    Primary hyperparathyroidism (PHPT) is a common endocrinological process, characterized by chronic elevation of serum concentrations of calcium and parathyroid hormone (PTH). Many years ago, the most frequent forms of clinical presentation were symptomatic renal or skeletal disease with moderate or severe hypercalcemia; however, currently, most patients have few symptoms and mild hypercalcemia. A new form of presentation called normocalcemic PHPT has also been described but clinical consequences are not well established. The biochemical profile of PHPT is characterized by hypercalcemia and high or inappropriately normal PTH concentrations. Parathyroidectomy is the only definitive cure. Medical treatment with the calcimimetic cinacalcet has been shown to normalize calcemia in a high percentage of cases. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  5. Primary Hyperoxaluria

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    Jérôme Harambat

    2011-01-01

    Full Text Available Primary hyperoxalurias (PH are inborn errors in the metabolism of glyoxylate and oxalate. PH type 1, the most common form, is an autosomal recessive disorder caused by a deficiency of the liver-specific enzyme alanine, glyoxylate aminotransferase (AGT resulting in overproduction and excessive urinary excretion of oxalate. Recurrent urolithiasis and nephrocalcinosis are the hallmarks of the disease. As glomerular filtration rate decreases due to progressive renal damage, oxalate accumulates leading to systemic oxalosis. Diagnosis is often delayed and is based on clinical and sonographic findings, urinary oxalate assessment, DNA analysis, and, if necessary, direct AGT activity measurement in liver biopsy tissue. Early initiation of conservative treatment, including high fluid intake, inhibitors of calcium oxalate crystallization, and pyridoxine in responsive cases, can help to maintain renal function in compliant subjects. In end-stage renal disease patients, the best outcomes have been achieved with combined liver-kidney transplantation which corrects the enzyme defect.

  6. Salt bridges regulate both dimer formation and monomeric flexibility in HdeB and may have a role in periplasmic chaperone function.

    Science.gov (United States)

    Wang, Wenjian; Rasmussen, Tim; Harding, Amanda J; Booth, Nuala A; Booth, Ian R; Naismith, James H

    2012-01-20

    Escherichia coli and Gram-negative bacteria that live in the human gut must be able to tolerate rapid and large changes in environmental pH. Low pH irreversibly denatures and precipitates many bacterial proteins. While cytoplasmic proteins are well buffered against such swings, periplasmic proteins are not. Instead, it appears that some bacteria utilize chaperone proteins that stabilize periplasmic proteins, preventing their precipitation. Two highly expressed and related proteins, HdeA and HdeB, have been identified as acid-activated chaperones. The structure of HdeA is known and a mechanism for activation has been proposed. In this model, dimeric HdeA dissociates at low pH, and the exposed dimeric interface binds exposed hydrophobic surfaces of acid-denatured proteins, preventing their irreversible aggregation. We now report the structure and biophysical characterization of the HdeB protein. The monomer of HdeB shares a similar structure with HdeA, but its dimeric interface is different in composition and spatial location. We have used fluorescence to study the behavior of HdeB as pH is lowered, and like HdeA, it dissociates to monomers. We have identified one of the key intersubunit interactions that controls pH-induced monomerization. Our analysis identifies a structural interaction within the HdeB monomer that is disrupted as pH is lowered, leading to enhanced structural flexibility.

  7. Salt Bridges Regulate Both Dimer Formation and Monomeric Flexibility in HdeB and May Have a Role in Periplasmic Chaperone Function

    Science.gov (United States)

    Wang, Wenjian; Rasmussen, Tim; Harding, Amanda J.; Booth, Nuala A.; Booth, Ian R.; Naismith, James H.

    2012-01-01

    Escherichia coli and Gram-negative bacteria that live in the human gut must be able to tolerate rapid and large changes in environmental pH. Low pH irreversibly denatures and precipitates many bacterial proteins. While cytoplasmic proteins are well buffered against such swings, periplasmic proteins are not. Instead, it appears that some bacteria utilize chaperone proteins that stabilize periplasmic proteins, preventing their precipitation. Two highly expressed and related proteins, HdeA and HdeB, have been identified as acid-activated chaperones. The structure of HdeA is known and a mechanism for activation has been proposed. In this model, dimeric HdeA dissociates at low pH, and the exposed dimeric interface binds exposed hydrophobic surfaces of acid-denatured proteins, preventing their irreversible aggregation. We now report the structure and biophysical characterization of the HdeB protein. The monomer of HdeB shares a similar structure with HdeA, but its dimeric interface is different in composition and spatial location. We have used fluorescence to study the behavior of HdeB as pH is lowered, and like HdeA, it dissociates to monomers. We have identified one of the key intersubunit interactions that controls pH-induced monomerization. Our analysis identifies a structural interaction within the HdeB monomer that is disrupted as pH is lowered, leading to enhanced structural flexibility. PMID:22138344

  8. The sigma-1 receptors are present in monomeric and oligomeric forms in living cells in the presence and absence of ligands

    Science.gov (United States)

    Singh, Deo R.; Biener, Gabriel; Yang, Jay; Oliver, Julie A.; Ruoho, Arnold; Raicu, Valerică

    2015-01-01

    The sigma-1 receptor (S1R) is a 223-amino-acid membrane protein that resides in the endoplasmic reticulum and the plasma membrane of some mammalian cells. The S1R is regulated by various synthetic molecules including (+)-pentazocine, cocaine and haloperidol and endogenous molecules such as sphingosine, dimethyltryptamine and dehydroepiandrosterone. Ligand-regulated protein chaperone functions linked to oxidative stress and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and neuropathic pain have been attributed to the S1R. Several client proteins that interact with S1R have been identified including various types of ion channels and G-protein coupled receptors (GPCRs). When S1R constructs containing C-terminal monomeric GFP2 and YFP fusions were co-expressed in COS-7 cells and subjected to FRET spectrometry analysis, monomers, dimers and higher oligomeric forms of S1R were identified under non-liganded conditions. In the presence of the prototypic S1R agonist, (+)-pentazocine, however, monomers and dimers were the prevailing forms of S1R. The prototypic antagonist, haloperidol, on the other hand, favoured higher order S1R oligomers. These data, in sum, indicate that heterologously expressed S1Rs occur in vivo in COS-7 cells in multiple oligomeric forms and that S1R ligands alter these oligomeric structures. We suggest that the S1R oligomerization states may regulate its function(s). PMID:25510962

  9. Structural and enzymatic insights into Lambda glutathione transferases from Populus trichocarpa, monomeric enzymes constituting an early divergent class specific to terrestrial plants.

    Science.gov (United States)

    Lallement, Pierre-Alexandre; Meux, Edgar; Gualberto, José M; Prosper, Pascalita; Didierjean, Claude; Saul, Frederick; Haouz, Ahmed; Rouhier, Nicolas; Hecker, Arnaud

    2014-08-15

    GSTs represent a superfamily of multifunctional proteins which play crucial roles in detoxification processes and secondary metabolism. Instead of promoting the conjugation of glutathione to acceptor molecules as do most GSTs, members of the Lambda class (GSTLs) catalyse deglutathionylation reactions via a catalytic cysteine residue. Three GSTL genes (Pt-GSTL1, Pt-GSTL2 and Pt-GSTL3) are present in Populus trichocarpa, but two transcripts, differing in their 5' extremities, were identified for Pt-GSTL3. Transcripts for these genes were primarily found in flowers, fruits, petioles and buds, but not in leaves and roots, suggesting roles associated with secondary metabolism in these organs. The expression of GFP-fusion proteins in tobacco showed that Pt-GSTL1 is localized in plastids, whereas Pt-GSTL2 and Pt-GSTL3A and Pt-GSTL3B are found in both the cytoplasm and the nucleus. The resolution of Pt-GSTL1 and Pt-GSTL3 structures by X-ray crystallography indicated that, although these proteins adopt a canonical GST fold quite similar to that found in dimeric Omega GSTs, their non-plant counterparts, they are strictly monomeric. This might explain some differences in the enzymatic properties of both enzyme types. Finally, from competition experiments between aromatic substrates and a fluorescent probe, we determined that the recognition of glutathionylated substrates is favoured over non-glutathionylated forms.

  10. Solvent exposure of Tyr10 as a probe of structural differences between monomeric and aggregated forms of the amyloid-β peptide

    Science.gov (United States)

    Aran Terol, Pablo; Kumita, Janet R.; Hook, Sharon C.; Dobson, Christopher M.; Esbjörner, Elin K.

    2015-01-01

    Aggregation of amyloid-β (Aβ) peptides is a characteristic pathological feature of Alzheimer's disease. We have exploited the relationship between solvent exposure and intrinsic fluorescence of a single tyrosine residue, Tyr10, in the Aβ sequence to probe structural features of the monomeric, oligomeric and fibrillar forms of the 42-residue Aβ1-42. By monitoring the quenching of Tyr10 fluorescence upon addition of water-soluble acrylamide, we show that in Aβ1-42 oligomers this residue is solvent-exposed to a similar extent to that found in the unfolded monomer. By contrast, Tyr10 is significantly shielded from acrylamide quenching in Aβ1-42 fibrils, consistent with its proximity to the fibrillar cross-β core. Furthermore, circular dichroism measurements reveal that Aβ1-42 oligomers have a considerably lower β-sheet content than the Aβ1-42 fibrils, indicative of a less ordered molecular arrangement in the former. Taken together these findings suggest significant differences in the structural assembly of oligomers and fibrils that are consistent with differences in their biological effects. PMID:26551456

  11. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O' Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  12. Effect of the gamma radiation in the properties of PEBD / amphiprotic starch blend;Efeito da radiacao gama nas propriedades da blenda de PEBD / amido anfotero

    Energy Technology Data Exchange (ETDEWEB)

    Texeira, Magno F.H.B.I.; Caetano, Viviane F.; Ferreira, Flavia G.D.; Almeida, Yeda M.B. de; Vinhas, Gloria M., E-mail: gloria.vinhas@ufpe.b [Universidade Federal de Pernambuco (DEQ/UFPE), Recife, PE (Brazil). Dept. de Engenharia Quimica

    2009-07-01

    The degradation of the polyethylene of low density (PEBD) it can be accelerated through the addition of natural polymer, minimizing the impact caused by the residues discarded in the environment. In this work the effect of the radiation gamma was evaluated in the PEBD / amphiprotic starch blend, in the doses of 25, 60 and 120 kGy. This blend after exposed to gamma radiation was analyzed by differential scanning calorimeter (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and mechanical properties. The blends after irradiation in the doses of 60 and 25 kGy had not presented change in the melting point temperature. Already the blends radiated in the dose of 120 kGy presented two melting point temperatures. Through the analyses in the infrared was detected the presence of the group carbonyl and primary and secondary alcohols as a result of the structural alteration in function of the radiolytic degradation. In the mechanical rehearsals, the blends presented decrease in the specific deformation in the rupture and in the module of elasticity when irradiated in the doses of 25, 60 and 120 kGy, respectively. Already the tension results in the rupture stayed practically unaffected with the effect of the gamma radiation. (author)

  13. Primary immunodeficiency

    Directory of Open Access Journals (Sweden)

    McCusker Christine

    2011-11-01

    Full Text Available Abstract Primary immunodeficiency disorder (PID refers to a heterogeneous group of over 130 disorders that result from defects in immune system development and/or function. PIDs are broadly classified as disorders of adaptive immunity (i.e., T-cell, B-cell or combined immunodeficiencies or of innate immunity (e.g., phagocyte and complement disorders. Although the clinical manifestations of PIDs are highly variable, most disorders involve at least an increased susceptibility to infection. Early diagnosis and treatment are imperative for preventing significant disease-associated morbidity and, therefore, consultation with a clinical immunologist is essential. PIDs should be suspected in patients with: recurrent sinus or ear infections or pneumonias within a 1 year period; failure to thrive; poor response to prolonged use of antibiotics; persistent thrush or skin abscesses; or a family history of PID. Patients with multiple autoimmune diseases should also be evaluated. Diagnostic testing often involves lymphocyte proliferation assays, flow cytometry, measurement of serum immunoglobulin (Ig levels, assessment of serum specific antibody titers in response to vaccine antigens, neutrophil function assays, stimulation assays for cytokine responses, and complement studies. The treatment of PIDs is complex and generally requires both supportive and definitive strategies. Ig replacement therapy is the mainstay of therapy for B-cell disorders, and is also an important supportive treatment for many patients with combined immunodeficiency disorders. The heterogeneous group of disorders involving the T-cell arm of the adaptive system, such as severe combined immunodeficiency (SCID, require immune reconstitution as soon as possible. The treatment of innate immunodeficiency disorders varies depending on the type of defect, but may involve antifungal and antibiotic prophylaxis, cytokine replacement, vaccinations and bone marrow transplantation. This article

  14. Otimização das condições de cultivo para a produção de amilases pelo termofílico Bacillus sp. e hidrólise de amidos pela ação da enzima Optimization of culture conditions for the production of amylases by thermophilic Bacillus sp. and hydrolysis of starches by the action of the enzymes

    Directory of Open Access Journals (Sweden)

    Raquel Vieira de Carvalho

    2008-06-01

    Full Text Available A otimização das condições de cultivo para a produção de α-amilase por um termofílico Bacillus sp. cepa SMIA-2 foi realizada. Além disso, a hidrólise enzimática do amido, proveniente de várias fontes tais como batata, mandioca e milho, foi também investigada. A produção de α-amilase por Bacillus sp. SMIA-2, cultivado em meio líquido contendo amido (5 g.L-1 como fonte de carbono e suplementado com 0,5 g.L-1 de proteínas do soro de leite e 2 g.L-1 de peptona, alcançou o máximo em 32 horas com níveis de 37 U.mL-1. O microrganismo foi capaz de utilizar diversas fontes de carbono, porém a atividade da amilase variou com cada fonte. O amido foi a melhor fonte de carbono para a secreção da amilase, enquanto a sacarose, lactose, maltose, galactose e glicose não foram muito efetivas. Uma redução na concentração de amido de até 2,5 g.L-1 no meio de cultura melhorou o crescimento do organismo e a atividade enzimática. Em altas concentrações de amido, a produção da enzima foi comparativamente menor. Em relação às fontes de nitrogênio orgânico e inorgânico, a peptona (2 g.L-1 foi considerada a melhor. Considerando a quantidade de proteínas do soro de leite no meio de cultivo, a concentração de 0,25 g.L-1 foi considerada a mais efetiva para a secreção da α-amilase pelo microrganismo. A produção máxima da atividade enzimática foi observada a 50 °C e pH 8,5. A enzima foi capaz de degradar todos os amidos testados. A hidrólise do amido de batata resultou num alto rendimento de açúcares redutores em comparação às outras fontes de amido. Amido solúvel e amido de mandioca ocuparam, respectivamente, a segunda e terceira posição em relação à liberação dos açúcares redutores, enquanto que a amilase estudada mostrou apenas uma ligeira afinidade pelo amido de milho. Com o aumento da temperatura da reação para 70 °C, a hidrólise dos substratos, com exceção do amido solúvel, resultou em maiores

  15. Analysis of amino acid residues involved in cold activity of monomeric isocitrate dehydrogenase from psychrophilic bacteria, Colwellia maris and Colwellia psychrerythraea.

    Science.gov (United States)

    Yasuda, Wataru; Kobayashi, Miyuki; Takada, Yasuhiro

    2013-11-01

    Monomeric isocitrate dehydrogenases from psychrophilic bacteria, Colwellia maris and Colwellia psychrerythraea (CmIDH-II and CpIDH-M, respectively) are cold-adapted enzymes and show a high degree of amino acid sequential identity to each other (77%). However, maximum activity of CpIDH-M at optimum temperature is much less than that of CmIDH-II. In the C-terminal region 3 of these enzymes, which was suggested from previous study to be responsible for their distinct catalytic ability, several sequential differences of amino acid residue are present. Among them, ten amino acid residues were exchanged between them by site-directed mutagenesis and several properties of the mutated enzymes were examined in this study. The mutated enzymes of CmIDH-II substituted its Gln671, Leu724 and Phe735 residues with the corresponding residues of CpIDH-M (termed Q671K, L724Q and F735L, respectively) showed lower specific activity and thermostability for activity than the wild-type enzyme. Furthermore, the decreased specific activity was also observed in L693F. In contrast, the corresponding mutants of CpIDH-M, F693L, Q724L and L735F, showed the increased specific activity and thermostability for activity. The catalytic efficiency (k(cat)/K(m)) values of these mutated CmIDH-II and CpIDH-M were lower and higher than those of their wild-type IDHs, respectively. These results suggest that the Gln671, Leu693, Leu724 and Phe735 residues of CmIDH-II are important for exerting its high catalytic ability.

  16. Effect of the disulfide bond on the monomeric structure of human amylin studied by combined Hamiltonian and temperature replica exchange molecular dynamics simulations.

    Science.gov (United States)

    Laghaei, Rozita; Mousseau, Normand; Wei, Guanghong

    2010-05-27

    The human Islet amyloid polypeptide (hIAPP or amylin) is a 37-residue peptide hormone that is normally cosecreted with insulin by the pancreatic beta-cells. In patients with type 2 diabetes, hIAPP deposits as amyloid fibrils in the extracellular spaces of the pancreatic islets. Recent experimental studies show that the intramolecular disulfide bond between Cys2 and Cys7 plays a central role in the process of fibril formation. However, the effect of the disulfide bond on the intrinsic structural properties of monomeric hIAPP is yet to be determined. In this study, we characterize the atomic structure and the thermodynamics of full-length hIAPP in the presence and absence of a disulfide bond using extensive combined Hamiltonian and temperature replica exchange molecular dynamics simulations (HT-REMD) with a coarse grained protein force field. Our simulations show that HT-REMD is more efficient in sampling than temperature REMD. On the basis of a total simulation time of 28 mus, we find that, although native hIAPP (in the presence of a disulfide bond) essentially adopts a disordered conformation in solution, consistent with the signal measured by ultraviolet-circular dichroism (UV-CD) spectroscopy, it also transiently samples alpha-helical structure for residues 5-16. In comparison with the N-terminal region, the C-terminal region is highly disordered and populates a much lesser content of isolated beta-strand conformation for residues 22-26 and 30-35. Moreover, the absence of the disulfide bond greatly decreases the extent of helix formed throughout residues 5-9 in favor of random coil and beta-sheet structure. Implications of the stabilization of N-terminal helical structure by disulfide bond on the initialization of hIAPP amyloid formation are discussed.

  17. Monomeric Immunoglobulin A from Plasma Inhibits Human Th17 Responses In Vitro Independent of FcαRI and DC-SIGN

    Science.gov (United States)

    Saha, Chaitrali; Das, Mrinmoy; Patil, Veerupaxagouda; Stephen-Victor, Emmanuel; Sharma, Meenu; Wymann, Sandra; Jordi, Monika; Vonarburg, Cédric; Kaveri, Srini V.; Bayry, Jagadeesh

    2017-01-01

    Circulating immunoglobulins including immunoglobulin G (IgG) and IgM play a critical role in the immune homeostasis by modulating functions of immune cells. These functions are mediated in part by natural antibodies. However, despite being second most abundant antibody in the circulation, the immunoregulatory function of IgA is relatively unexplored. As Th17 cells are the key mediators of a variety of autoimmune, inflammatory, and allergic diseases, we investigated the ability of monomeric IgA (mIgA) isolated from pooled plasma of healthy donors to modulate human Th17 cells. We show that mIgA inhibits differentiation and amplification of human Th17 cells and the production of their effector cytokine IL-17A. mIgA also suppresses IFN-γ responses under these experimental conditions. Suppressive effect of mIgA on Th17 responses is associated with reciprocal expansion of FoxP3-positive regulatory T cells. The effect of mIgA on Th17 cells is dependent on F(ab′)2 fragments and independent of FcαRI (CD89) and DC-SIGN. Mechanistically, the modulatory effect of mIgA on Th17 cells implicates suppression of phosphorylation of signal transducer and activator of transcription 3. Furthermore, mIgA binds to CD4+ T cells and recognizes in a dose-dependent manner the receptors for cytokines (IL-6Rα and IL-1RI) that mediate Th17 responses. Our findings thus reveal novel anti-inflammatory functions of IgA and suggest potential therapeutic utility of mIgA in autoimmune and inflammatory diseases that implicate Th17 cells. PMID:28352269

  18. Monomeric TonB and the Ton box are required for the Formation of a High-Affinity Transporter-TonB Complex†

    Science.gov (United States)

    Freed, Daniel M.; Lukasik, Stephen M.; Sikora, Arthur; Mokdad, Audrey; Cafiso, David S.

    2013-01-01

    The energy-dependent uptake of trace nutrients by Gram-negative bacteria involves the coupling of an outer membrane transport protein to the transperiplasmic protein TonB. In the present study, a soluble construct of Escherichia coli TonB (residues 33–239) was used to determine the affinity of TonB to the outer membrane transporters BtuB, FecA and FhuA. Using fluorescence anisotropy, TonB(33–239) was found to bind with high-affinity (tens of nM) to both BtuB and FhuA; however, no high-affinity binding was observed to FecA. In BtuB, the high affinity binding of TonB(33–239) was eliminated by mutations in the Ton box, which yield transport-defective protein, or by the addition of a Colicin E3 fragment, which stabilizes the Ton box in a folded state. These results indicate that transport requires a high-affinity transporter-TonB interaction that is mediated by the Ton box. Characterization of TonB(33–239) using double electron-electron resonance (DEER) demonstrates that a significant population of TonB(33–239) exists as a dimer; moreover, interspin distances are in approximate agreement with interlocked dimers observed previously by crystallography for shorter TonB fragments. When bound to the outer membrane transporter, DEER shows that the TonB(33–239) dimer is converted to a monomeric form, suggesting that a dimer-monomer conversion takes place at the outer membrane during the TonB-dependent transport cycle. PMID:23517233

  19. Monomeric TonB and the Ton box are required for the formation of a high-affinity transporter-TonB complex.

    Science.gov (United States)

    Freed, Daniel M; Lukasik, Stephen M; Sikora, Arthur; Mokdad, Audrey; Cafiso, David S

    2013-04-16

    The energy-dependent uptake of trace nutrients by Gram-negative bacteria involves the coupling of an outer membrane transport protein to the transperiplasmic protein TonB. In this study, a soluble construct of Escherichia coli TonB (residues 33-239) was used to determine the affinity of TonB for outer membrane transporters BtuB, FecA, and FhuA. Using fluorescence anisotropy, TonB(33-239) was found to bind with high affinity (tens of nanomolar) to both BtuB and FhuA; however, no high-affinity binding to FecA was observed. In BtuB, the high-affinity binding of TonB(33-239) was eliminated by mutations in the Ton box, which yield transport-defective protein, or by the addition of a Colicin E3 fragment, which stabilizes the Ton box in a folded state. These results indicate that transport requires a high-affinity transporter-TonB interaction that is mediated by the Ton box. Characterization of TonB(33-239) using double electron-electron resonance (DEER) demonstrates that a significant population of TonB(33-239) exists as a dimer; moreover, interspin distances are in approximate agreement with interlocked dimers observed previously by crystallography for shorter TonB fragments. When the TonB(33-239) dimer is bound to the outer membrane transporter, DEER shows that the TonB(33-239) dimer is converted to a monomeric form, suggesting that a dimer-monomer conversion takes place at the outer membrane during the TonB-dependent transport cycle.

  20. Resolution of two native monomeric 90kDa nitrate reductase active proteins from Shewanella gelidimarina and the sequence of two napA genes.

    Science.gov (United States)

    Simpson, Philippa J L; McKinzie, Audra A; Codd, Rachel

    2010-07-16

    The reduction of nitrate to nitrite in the bacterial periplasm occurs in the 90kDa NapA subunit of the periplasmic nitrate reductase (NAP) system. Most Shewanella genomes contain two nap operons: napEDABC and napDAGHB, which is an unusual feature of this genus. Two native, monomeric, 90kDa nitrate reductase active proteins were resolved by hydrophobic interaction chromatography from aerobic cultures of Shewanella gelidimarina replete with reduced nitrogen compounds. The 90kDa protein obtained in higher yield was characterized as NapA by electronic absorption and electron paramagnetic resonance spectroscopies and was identified by LC/MS/MS and MALDI-TOF/TOF MS as NapA from the napEDABC-type operon. The other 90kDa protein, which was unstable and produced in low yields, was posited as NapA from the napDAGHB-type operon. Two napA genes have been sequenced from the napEDABC-type and napDAGHB-type operons of S. gelidimarina. Native NAP from S. putrefaciens was resolved as one NapA monomer and one NapAB heterodimer. Two amino acid substitutions in NapA correlated with the isolation of NAP as a NapA monomer or a NapAB heterodimer. The resolution of native, redox-active NapA isoforms in Shewanella provides new insight into the respiratory versatility of this genus, which has implications in bioremediation and the assembly of microbial fuel cells.

  1. X-ray Crystal Structures of Monomeric and Dimeric Peptide Inhibitors in Complex with the Human Neonatal Fc Receptor, FcRn

    Energy Technology Data Exchange (ETDEWEB)

    Mezo, Adam R.; Sridhar, Vandana; Badger, John; Sakorafas, Paul; Nienaber, Vicki (Zenobia); (Biogen)

    2010-10-28

    The neonatal Fc receptor, FcRn, is responsible for the long half-life of IgG molecules in vivo and is a potential therapeutic target for the treatment of autoimmune diseases. A family of peptides comprising the consensus motif GHFGGXY, where X is preferably a hydrophobic amino acid, was shown previously to inhibit the human IgG:human FcRn protein-protein interaction (Mezo, A. R., McDonnell, K. A., Tan Hehir, C. A., Low, S. C., Palombella, V. J., Stattel, J. M., Kamphaus, G. D., Fraley, C., Zhang, Y., Dumont, J. A., and Bitonti, A. J. (2008) Proc. Natl. Acad. Sci. U.S.A., 105, 2337-2342). Herein, the x-ray crystal structure of a representative monomeric peptide in complex with human FcRn was solved to 2.6 {angstrom} resolution. The structure shows that the peptide binds to human FcRn at the same general binding site as does the Fc domain of IgG. The data correlate well with structure-activity relationship data relating to how the peptide family binds to human FcRn. In addition, the x-ray crystal structure of a representative dimeric peptide in complex with human FcRn shows how the bivalent ligand can bridge two FcRn molecules, which may be relevant to the mechanism by which the dimeric peptides inhibit FcRn and increase IgG catabolism in vivo. Modeling of the peptide:FcRn structure as compared with available structural data on Fc and FcRn suggest that the His-6 and Phe-7 (peptide) partially mimic the interaction of His-310 and Ile-253 (Fc) in binding to FcRn, but using a different backbone topology.

  2. The photophysics of monomeric bacteriochlorophylls c and d and their derivatives: properties of the triplet state and singlet oxygen photogeneration and quenching

    Science.gov (United States)

    Krasnovsky, A. A. Jr; Cheng, P.; Blankenship, R. E.; Moore, T. A.; Gust, D.

    1993-01-01

    Measurements of pigment triplet-triplet absorption, pigment phosphorescence and photosensitized singlet oxygen luminescence were carried out on solutions containing monomeric bacteriochlorophylls (Bchl) c and d, isolated from green photosynthetic bacteria, and their magnesium-free and farnesyl-free analogs. The energies of the pigment triplet states fell in the range 1.29-1.34 eV. The triplet lifetimes in aerobic solutions were 200-250 ns; they increased to 280 +/- 70 microseconds after nitrogen purging in liquid solutions and to 0.7-2.1 ms in a solid matrix at ambient or liquid nitrogen temperatures. Rate constants for quenching of the pigment triplet state by oxygen were (2.0-2.5) x 10(9) M-1 s-1, which is close to 1/9 of the rate constant for diffusion-controlled reactions. This quenching was accompanied by singlet oxygen formation. The quantum yields for the triplet state formation and singlet oxygen production were 55-75% in air-saturated solutions. Singlet oxygen quenching by ground-state pigment molecules was observed. Quenching was the most efficient for magnesium-containing pigments, kq = (0.31-1.2) x 10(9) M-1 s-1. It is caused mainly by a physical process of singlet oxygen (1O2) deactivation. Thus, Bchl c and d and their derivatives, as well as chlorophyll and Bchl a, combine a high efficiency of singlet oxygen production with the ability to protect photochemical and photobiological systems against damage by singlet oxygen.

  3. [Primary lipodystrophies].

    Science.gov (United States)

    Capeau, J; Magré, J; Lascols, O; Caron, M; Béréziat, V; Vigouroux, C

    2007-02-01

    Primary lipodystrophies represent a heterogeneous group of very rare diseases with a prevalence of less than 1 case for 100.000, inherited or acquired, caracterized by a loss of body fat either generalized or localized (lipoatrophy). In some forms, lipoatrophy is associated with a selective hypertrophy of other fat depots. Clinical signs of insulin resistance are often present: acanthosis nigricans, signs of hyperandrogenism. All lipodystrophies are associated with dysmetabolic alterations with insulin resistance, altered glucose tolerance or diabetes and hypertriglyceridemia leading to a risk of acute pancreatitis. Chronic complications are those resulting from diabetes involving the retina, kidney and nerves, cardiovascular complications and steatotic liver lesions that could result in cirrhosis. Genetic forms of generalized lipodystrophy (or Berardinelli-Seip syndrome) result, in most cases, from recessive mutations in one of two genes: either BSCL2 coding seipin or BSCL1 coding AGPAT2, an acyl-transferase involved in triglyceride synthesis. Acquired generalized lipodystrophy (Lawrence syndrome) is of unknown origin but is sometimes associated with signs of autoimmunity. Partial lipodystrophies can be familial with dominant transmission. Heterozygous mutations have been identified in the LMNA gene encoding nuclear lamin A/C belonging to the nuclear lamina, or in PPARG encoding the adipogenic transcription factor PPARgamma. Some less typical lipodystrophies, associated with signs of premature aging, have been linked to mutations in LMNA or in the ZMPSTE24 gene encoding the protease responsible for the maturation of prelamin A into lamin A. Acquired partial lipodystrophy (Barraquer-Simons syndrome) is characterized by cephalothoracic fat loss. Its aetiology is unknown but mutations in LMNB2, encoding the lamina protein lamin B2, could represent susceptibility factors. Highly active antiretroviral treatments for HIV infection are currently the most frequent cause

  4. Estabilidade de géis de amido de milho normal, ceroso e com alto teor de amilose adicionados de gomas guar e xantana durante os processos de congelamento e descongelamento Freeze-thaw stability of normal, waxy and high amylose corn starch gels with added guar and xanthan gums

    Directory of Open Access Journals (Sweden)

    Fernanda Hart Weber

    2008-06-01

    Full Text Available O objetivo do presente trabalho foi estudar os efeitos das gomas guar e xantana sobre a estabilidade dos géis de amido de milho normal, ceroso e com alto teor de amilose submetidos aos processos de congelamento e descongelamento. Os géis desses amidos, com concentração total de sólidos de 10% e adicionados das gomas (0,15; 0,50; 0,85 e 1%, foram submetidos a 5 ciclos de congelamento (20 horas a -18 °C e descongelamento (4 horas a 25 °C, com exceção dos géis com alto teor de amilose, que foram submetidos a apenas 1 ciclo, devido à perda da estrutura de gel. A determinação da sinérese (porcentagem de água liberada foi realizada pela diferença entre a massa inicial e a massa final das amostras. O gel de amido de milho normal liberou 74,45% de água, sendo que a adição de 1% da goma xantana reduziu significativamente a sinérese para 66,43%. A adição de 0,85 e 1% da goma xantana também reduziu a sinérese dos géis de amido ceroso. O menor teor de sinérese foi obtido com a utilização de 1% de goma xantana ao gel de amido de milho com alto teor de amilose, evidenciando a ação crioprotetora desta goma.The objective of the present work was to study the effects of guar and xanthan gums on the stability of normal, waxy and high amylose corn starch gels, submitted to freeze-thaw processes. The gels of these starches with a total solids content of 10% and added gums (0.15;0.50;0.85and1%, were submitted to 5 freezing (20 hours, -18 °C and thawing (4 hours, 25 °C cycles, with exception of the high amylose gels that were submitted to only 1 cycle. Syneresis (% water released was determined by the difference between the initial and final masses of the samples. The normal corn starch gel released 74.45% water and the addition of 1% xanthan gum significantly reduced syneresis to 66.43%. The incorporation of 0.85 and 1% xanthan gum also reduced syneresis of waxy starch gels. The lowest level of syneresis was reached with the use of 1

  5. CARACTERIZACIÓN MORFOLÓGICA DE PELÍCULAS BIODEGRADABLES A PARTIR DE ALMIDÓN MODIFICADO DE YUCA, AGENTE ANTIMICROBIANO Y PLASTIFICANTE CARACTERIZAÇÃO MORFOLÓGICA DE FILMES BIODEGRADÁVEIS A PARTIR DE AMIDO MODIFICADO DE MANDIOCA, AGENTE ANTIMICROBIANO E PLASTIFICANTE MORPHOLOGICAL CHARACTERIZATION OF BIODEGRADABLE FILMS MADE FROM MODIFIED CASSAVA STARCH, ANTIMICROBIAL AGENT AND PLASTICIZER

    Directory of Open Access Journals (Sweden)

    REINALDO VELASCO M

    2012-12-01

    Full Text Available Se ha evaluado la morfología superficial de almidones termoplásticos (TPS obtenidos de tres variedades de almidón modificado de yuca, plastificante y un agente antimicrobiano. Las películas fueron obtenidas por extrusión soplado, se acondicionaron a una temperatura de 25°C y humedad relativa de 50% durante 48 horas y se extendieron sobre un portaobjetos; se procedió a tomar las fotomicrografías con los objetivos de 4x y 10x. Se usó la técnica microscopia óptica de alta resolución (MOAR para caracterizar las imágenes. La técnica mostró que la adición del plastificante afecta la microestructura de películas de almidón de yuca demostrando una falta de homogeneidad, sin embargo se presentaron regiones lisas relacionadas con el tamaño y forma del gránulo de almidón, la concentración del plastificante y las condiciones del proceso de extrusión como la velocidad del tornillo y el perfil de temperatura. Esta investigación contribuyó a caracterizar las propiedades microestructurales de los almidones termoplásticos, que son imprescindibles para la continuidad en el estudio de películas biodegradables.Avaliou-se a morfologia superficial dos amidos termoplásticos (TPS obtidos de três variedades de amido modificado da mandioca, plastificante e um agente antimicrobiano. Os filmes foram obtidos por extrusão soprada e espalhados sobre uma lâmina; passou - se a tomar as fotomicrografias com os objetivos de 4x e 10x. Foi usada a técnica da microscopia óptica de alta resolução (MOAR para caracterizar as imagens. A técnica mostrou que a adição do plastificante afeta a microestrutura dos filmes de amido de mandioca mostrando uma falta de homogeneidade, no entanto presentearam - se regiões lisas relacionadas com o tamanho y forma do granulo do amido, a concentração de plastificante e as condições do processo de extrusão como a velocidade do parafuso e o perfil de temperatura. Esta pesquisa contribuiu a caracterizar as

  6. Atividade da amilase no intestino delgado de coelhos alimentados com dietas contendo diferentes níveis de amido antes e após desmame = Amylase activity in the small intestine of rabbits fed with diets containing starch levels before and after weaning

    Directory of Open Access Journals (Sweden)

    Haroldo Garcia de Faria

    2006-07-01

    Full Text Available Para avaliar a atividade amilásica em coelhos após a desmama, foram utilizados 200 animais da Raça Nova Zelândia Branco, submetidos a diferentes padrões de alimentação desde a fase de lactação. Quarenta deles foram abatidos aos 35 dias de idade e 80, aos 50 e aos 70 dias de idade. Para modular o padrão de consumo de leite e ração antes da desmama, as ninhadas equalizadas em 8 láparos do nascimento até ao 16º dia de idade, a partir desta idade, até a desmama, foram submetidos à alta e baixa disponibilidade de leite, mantendo ninhadas com 4 ou 8 láparos recebendo dietas com nível normal (15% e alto (24% de amido. A partir da desmama, os animais de cada um dos 4 padrões de alimentação até a desmama passaram a receber as mesmasdietas com níveis normal e alto de amido, em um esquema fatorial 2x2x2 (ninhadas submetidas à baixa e alta disponibilidade de leite versus dois níveis de amido na dieta até a desmama versus doisníveis de amido na dieta após a desmama. Os resultados mostraram que a manutenção de ninhadas com 4 ou 8 animais entre o 16º e 35º dia de lactação não modificou (P>0,05 a atividade da amilase em qualquer das idades avaliadas após o desmame. O uso de dietas com alto teor de amido durante a lactação aumentou (POne experiment was carried out to study the amylase activity in the small intestine (jejunum and ileum of rabbits from litters maintained on different feeding patterns. Two hundred White New Zealand rabbits were analyzed, out of which 40 35- days-old rabbits, 80 50-days-old rabbits and 80 70-days-old rabbits were slaughtered. To modulate the pattern of feed and milk intake before weaning, the litters were modulated for eight young rabbits until 16 days old. From 16 days until weaning, they were submitted to low or high milkavailability, litters maintained with four or eight young rabbits receiving diets containing normal or high starch level. The animals were distributed in a factorial design 2

  7. A biodegradabilidade da blenda de poli(β-Hidroxibutirato-co-Valerato/amido anfótero na presença de microrganismos The Biodegradation of polyhydroxybutyrate-co-valerate/amphiprotic starch in the presence of microorganisms

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    Nadjane S. Coelho

    2008-09-01

    Full Text Available O crescimento do consumo de plásticos vem gerando grandes problemas ambientais, pois um polímero, uma vez descartado no ambiente, necessita de mais de cem anos para se degradar. O plástico ideal deve apresentar propriedades industriais desejáveis e, ao mesmo tempo ser degradável num período considerado satisfatório. Busca-se desenvolver plásticos com boas propriedades para embalagens e que possam ser biodegradados quando descartados ao ambiente. Neste trabalho avaliamos a biodegradação da blenda do copolímero poli(β-hidroxibutirato-co-valerato, PHB-HV, que é um termoplástico natural, biodegradável e biocompatível, e do amido anfótero, na proporção de 75 e 25% m/m, respectivamente. Os resultados foram obtidos através do teste de Sturm, uma metodologia para a avaliação da biodegradação na presença de uma cultura mista dos fungos Phanerochaete chrysosporium e Talaromyces wortmannii. Os resultados evidenciam a biodegradação da blenda em função do tempo, de acordo com os resultados do teste de Sturm, com o aparecimento de grupos carboxílicos terminais. Foi detectado também o aparecimento de nova simetria cristalina na estrutura polimérica.The increasing consumption of plastics has generated environmental problems because it takes more than a hundred years for a discarded polymer to degrade. The ideal plastic should present desirable industrial properties and be degradable within a satisfactory time period. Researches is conducted to plastics with good properties for packaging, but that are biodegradable when discarded to the environment. In this work we evaluated the biodegradation of the blend of the copolymer poly(hydroxybutyrate-hydroxyvalerate, PHB-HV, which is a natural, biodegradable and biocompatible thermoplastic, and of the starch amphiprotic, in the proportion of 75 and 25% m/m, respectively. The results were obtained through the Sturm test, a methodology for the evaluation of biodegradation in the presence

  8. A ruthenium-grafted hydrotalcite as a multifunctional catalyst for direct alpha-alkylation of nitriles with primary alcohols.

    Science.gov (United States)

    Motokura, Ken; Nishimura, Daisuke; Mori, Kohsuke; Mizugaki, Tomoo; Ebitani, Kohki; Kaneda, Kiyotomi

    2004-05-12

    Treatment of a hydrotacite, Mg6Al2(OH)16CO3, with an aqueous solution of RuCl3.nH2O afforded a monomeric Ru(IV) species on the surface of the hydrotalcite. This novel Ru-grafted hydrotalcite (Ru/HT) efficiently catalyzed alpha-alkylation of nitriles with primary alcohols through the cooperative catalysis between the Ru species and the surface base sites. The catalyst system could be further extended for the one-pot synthesis of alpha,alpha-dialkylated phenylacetonitriles via the base-catalyzed Michael reaction of alpha-alkylated phenylacetonitrile with activate olefins.

  9. Genetic and spectrally distinct in vivo imaging: embryonic stem cells and mice with widespread expression of a monomeric red fluorescent protein

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    Hadjantonakis Anna-Katerina

    2005-07-01

    permit deeper tissue imaging. Our work in generating CAG::mRFP1 transgenic ES cells and mice demonstrates the developmental neutrality of mRFP1 in an organismal context. It paves the way for the use of DsRed-based monomeric RFPs in transgenic and gene targeted approaches which often necessitate spatially and/or temporally restricted reporter expression. Moreover animals of the CAG::mRFP1 transgenic strain serve as a source of RFP tagged tissue for the derivation of cell lines and explant, transplant and embryo chimera experiments.

  10. Intercalation of Amido Cationic Drug with Montmorillonite

    Institute of Scientific and Technical Information of China (English)

    ZHENG Junping; WANG Hongyan; ZHUANG Hong; XI Lifei; YAO Kangde

    2007-01-01

    The intercalation of drug molecules with montmorillonit (MMT) using Acyclovir (ACV) as the model drug was focused on. The optimum conditions were studied based on orthogonal design, such as intercalation time and temperature. The intercalation composites were characterized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR), and thermogravimetric analysis (TGA). The experimental results reveal that ACV is successfully intercalated into the interlayers of MMT. The in vitro release experiments reveal that ACV is released from MMT steadily and pH dependent

  11. Iodo e Amido! Ptose, miose e hemianidrose.

    OpenAIRE

    Ivo Julião; Mário Pires

    2014-01-01

    Apresenta-se um homem de 66 anos seguido em consulta de Ortopedia por cervicobraquialgia esquerda refratária e radiculopatiade C5 e C6. Realizou RMN que revelou lesão no ápex pulmonaresquerdo com destruição óssea adjacente, sendo internado no Serviço de Medicina para estudo dirigido com biópsia, que reveloucarcinoma epidermóide do pulmão. Apresentava ptose palpebral eanisocoria com miose esquerdas.

  12. Iodo e Amido! Ptose, miose e hemianidrose.

    Directory of Open Access Journals (Sweden)

    Ivo Julião

    2014-09-01

    Full Text Available Apresenta-se um homem de 66 anos seguido em consulta de Ortopedia por cervicobraquialgia esquerda refratária e radiculopatiade C5 e C6. Realizou RMN que revelou lesão no ápex pulmonaresquerdo com destruição óssea adjacente, sendo internado no Serviço de Medicina para estudo dirigido com biópsia, que reveloucarcinoma epidermóide do pulmão. Apresentava ptose palpebral eanisocoria com miose esquerdas.

  13. Fontes de amido de diferentes degradabilidades e sua substituição parcial por polpa de citrus em dietas para vacas leiteiras Starch sources with different degradabilities and their partial replacement by citrus pulp for lactating dairy cows

    Directory of Open Access Journals (Sweden)

    Alexandre Vaz Pires

    2002-04-01

    Full Text Available Foram utilizadas quatro vacas Holandesas, no terço final de lactação, canuladas no rúmen, com o objetivo de comparar milho moído fino, moído grosso ou floculado, assim como a substituição parcial dessas fontes de amido por polpa de citrus peletizada. O delineamento experimental utilizado foi um Quadrado Latino 5 x 4. As dietas continham silagem de milho como volumoso exclusivo e os tratamentos testados foram: milho moído fino (MF, floculado (F, moído grosso (MG, moído fino + polpa de citrus (MFP e floculado + polpa de citrus (FP. O tratamento MG resultou em menores produções de leite, gordura e proteína, enquanto que o tratamento MFP resultou em maiores produções de leite corrigido, gordura e proteína. As digestibilidades no trato total da MS, PB, FDN, FDA foram maiores para o tratamento FP, enquanto que o tratamento F teve efeito negativo na digestão de fibra. O pH ruminal foi menor para o tratamento FP. Os teores médios de N-amoniacal e AGV totais ruminais não foram afetados pelos tratamentos. O tratamento F reduziu as concentrações molares de acetato e butirato, enquanto que a inclusão de polpa favoreceu a produção ruminal destes. A glicose plasmática não foi afetada, mas os teores de N-uréico foram superiores no tratamento MFP comparados com MG.Four late lactating Holstein cows, canulated in rumen, were used in a 5x4 Latin Square Design to compare coarsely ground, finely ground and flaked corn and the partial replacement of these starch sources by citrus pulp. All diets contained corn silage as forage source. The treatments were finely ground corn (MF, steam-flaked corn (F, coarsely ground corn (MG, finely ground corn+ citrus pulp (MFP, steam-flaked corn + citrus pulp (FP. The MG treatment resulted in the lowest dry matter intake and lowest milk, fat and protein yields, while the FP treatment resulted in the highest dry matter intake, 3.5% fat corrected milk, fat and protein yields. The DM, CP, NDF and ADF total

  14. Proteína degradável no rúmen associada a fontes de amido de alta ou baixa degradabilidade: digestibilidade in vitro e desempenho de novilhos em crescimento Rumen degradable protein associated to starch sources of different ruminal degradability: in vitro digestibility and performance of growing steers

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    Saul Ferreira Caldas Neto

    2007-04-01

    Full Text Available Objetivou-se avaliar os efeitos de teores crescentes de proteína degradável no rúmen (PDR = 47, 52, 57 e 62% associados a fontes de amido de baixa (milho ou de alta (farinha de varredura de mandioca - FVM degradabilidade ruminal em rações com 50:50% volumoso:concentrado sobre a digestibilidade in vitro da MS (DIVMS e o ganho de peso de novilhos em crescimento. Para determinação da DIVMS, foi utilizada a técnica de dois estádios de Tilley & Terry (1963. As médias obtidas para a DIVMS foram submetidas às análises de variância e regressão em função do teor de PDR da ração. Para o ensaio de desempenho animal, foram utilizados 32 novilhos mestiços (Nelore x Red Angus, não-castrados (275 kg de PV, alojados em duplas, em delineamento experimental inteiramente casualizado. Não foi observado efeito do teor de PDR de dietas contendo milho sobre a DIVMS, indicando que não houve deficiência de nitrogênio e que, possivelmente, a digestibilidade da fonte de amido (milho foi o fator limitante. Observou-se efeito quadrático do teor de PDR sobre a DIVMS para as dietas contendo FVM, o que indica a ocorrência do efeito de sincronização entre a disponibilidade de energia e nitrogênio, permitindo aumento da atividade microbiana nos níveis mais elevados de PDR na ração e melhor utilização da energia proveniente da fonte de amido de alta degradabilidade ruminal. Não foi observado efeito dos diferentes teores de PDR e da fonte de amido de alta degradabilidade ruminal sobre o consumo de MS, o ganho de peso médio e a conversão alimentar dos animais.The objective of this study was to evaluate the effects of increasing levels of rumen-degradable protein (RDP = 47, 52, 57 and 62% associated to starch sources of low (corn and high (cassava by-product (CBP ruminal degradability on in vitro DM digestibility (IVDMD and average daily gain of growing steers. In vitro DM digestibility was determined by using the Tilley and Terry (1963 technique

  15. Hue-shifted monomeric variants of Clavularia cyan fluorescent protein: identification of the molecular determinants of color and applications in fluorescence imaging

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    Davidson Michael W

    2008-03-01

    Full Text Available Abstract Background In the 15 years that have passed since the cloning of Aequorea victoria green fluorescent protein (avGFP, the expanding set of fluorescent protein (FP variants has become entrenched as an indispensable toolkit for cell biology research. One of the latest additions to the toolkit is monomeric teal FP (mTFP1, a bright and photostable FP derived from Clavularia cyan FP. To gain insight into the molecular basis for the blue-shifted fluorescence emission we undertook a mutagenesis-based study of residues in the immediate environment of the chromophore. We also employed site-directed and random mutagenesis in combination with library screening to create new hues of mTFP1-derived variants with wavelength-shifted excitation and emission spectra. Results Our results demonstrate that the protein-chromophore interactions responsible for blue-shifting the absorbance and emission maxima of mTFP1 operate independently of the chromophore structure. This conclusion is supported by the observation that the Tyr67Trp and Tyr67His mutants of mTFP1 retain a blue-shifted fluorescence emission relative to their avGFP counterparts (that is, Tyr66Trp and Tyr66His. Based on previous work with close homologs, His197 and His163 are likely to be the residues with the greatest contribution towards blue-shifting the fluorescence emission. Indeed we have identified the substitutions His163Met and Thr73Ala that abolish or disrupt the interactions of these residues with the chromophore. The mTFP1-Thr73Ala/His163Met double mutant has an emission peak that is 23 nm red-shifted from that of mTFP1 itself. Directed evolution of this double mutant resulted in the development of mWasabi, a new green fluorescing protein that offers certain advantages over enhanced avGFP (EGFP. To assess the usefulness of mTFP1 and mWasabi in live cell imaging applications, we constructed and imaged more than 20 different fusion proteins. Conclusion Based on the results of our

  16. Effects of dexamethasone on proliferation of and fibronectin synthesis by human primary prostatic stromal cells in vitro.

    Science.gov (United States)

    Albrecht, M; Janssen, M; Konrad, L; Renneberg, H; Aumüller, G

    2002-02-01

    Glucocorticoids are anti inflammatory stress hormones and have been suggested to be involved in a large number of pathological processes. To test the effects of glucocorticoids on stromal prostatic cell growth and proliferation in vitro, the influence of a synthetic glucocorticoid (dexamethasone, dex) on recently established human primary cells from prostatic stroma (hPCPs) was analysed. The localization and distribution of the glucocorticoid receptor (GR) was investigated by immunohistochemistry. In addition, expression of the active isoform of the receptor (alpha-GR) was examined by reverse transcription PCR, and the effect of different doses of dex on proliferation of the stromal cells evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and amido black assays. alpha-GR mRNA was expressed by the hPCPs, and the GR protein was detected in the cytoplasm and nucleus of these cells. Incubating the cells with dex resulted in an enhanced cell proliferation that was mainly restricted to the fibroblasts. Moreover, fibronectin (FN) gene expression and secretion of the protein was increased by high doses of dex (> or = 10(-8) M), whereas low doses of dex (10(-10)M) showed no effect. Human prostatic stromal cells show sensitivity to dex in vitro, resulting in an increase in cell proliferation and FN synthesis. The authors assume that locally accumulating glucocorticoids can also influence the regulation of cell growth and extracellular matrix synthesis in the human prostate in vivo and may play a role in the pathologically altered prostate.

  17. Primary Considerations for Primary TEFL in China

    Institute of Scientific and Technical Information of China (English)

    Yvonne Griffiths

    2007-01-01

    This article will focus on five key areas relating to Primary TEFL in China. Firstly, the real TEFL context in Chinese primary schools will be discussed in terms of its special characteristics. Secondly, the current methodological approach will be examined from both a theoretical perspective, focusing on government (MOE) policy for primary TEFL, and a practical perspective, based on personal observations of classroom practice. The third section of the article will highlight some perceived shortcomings of current practice, while the fourth will outline the actual needs of primary learners in the Chinese educational system. Finally, the question of how teachers can meet these needs will be examined in relation to: methodological integration;integration of skills and sub-skills teaching/learning; and the exploitation of materials and activities to provide learners with three different types of language input and output opportunities (extensive, intensive and analysed: Swan, 2006).

  18. Brain tumor - primary - adults

    Science.gov (United States)

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  19. Primary Hyperparathyroidism: An Overview

    OpenAIRE

    Jessica MacKenzie-Feder; Sandra Sirrs; Donald Anderson; Jibran Sharif; Aneal Khan

    2011-01-01

    Primary hyperparathyroidism is a common condition that affects 0.3% of the general population. Primary and tertiary care specialists can encounter patients with primary hyperparathyroidism, and prompt recognition and treatment can greatly reduce morbidity and mortality from this disease. In this paper we will review the basic physiology of calcium homeostasis and then consider genetic associations as well as common etiologies and presentations of primary hyperparathyroidism. We will consider...

  20. Primary Meningeal Rhabdomyosarcoma

    OpenAIRE

    2011-01-01

    Primary meningeal rhabdomyosarcoma is a rare primary brain malignancy, with scant case reports. While most reports of primary intracranial rhabdomyosarcoma occur in pediatric patients, a handful of cases in adult patients have been reported in the medical literature. We report the case of a 44-year-old male who developed primary meningeal rhabdomyosarcoma. After developing episodes of right lower extremity weakness, word finding difficulty, and headaches, a brain magnetic resonance imagin...

  1. Primary Care's Dim Prognosis

    Science.gov (United States)

    Alper, Philip R.

    2010-01-01

    Given the chorus of approval for primary care emanating from every party to the health reform debate, one might suppose that the future for primary physicians is bright. Yet this is far from certain. And when one looks to history and recognizes that primary care medicine has failed virtually every conceivable market test in recent years, its…

  2. Investigating Primary Source Literacy

    Science.gov (United States)

    Archer, Joanne; Hanlon, Ann M.; Levine, Jennie A.

    2009-01-01

    Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind "primary source literacy". The study also evaluated students' strengths and weaknesses when conducting primary source research. (Contains 3…

  3. Primary Hyperparathyroidism: An Overview

    Directory of Open Access Journals (Sweden)

    Jessica MacKenzie-Feder

    2011-01-01

    Full Text Available Primary hyperparathyroidism is a common condition that affects 0.3% of the general population. Primary and tertiary care specialists can encounter patients with primary hyperparathyroidism, and prompt recognition and treatment can greatly reduce morbidity and mortality from this disease. In this paper we will review the basic physiology of calcium homeostasis and then consider genetic associations as well as common etiologies and presentations of primary hyperparathyroidism. We will consider emerging trends in detection and measurement of parathyroid hormone as well as available imaging modalities for the parathyroid glands. Surgical indications and approach will be reviewed as well as medical management of primary hyperparathyroidism with bisphosphonates and calcimimetics.

  4. Influence of filled d pi-manifold and L/L' ligands on the structure, basicity, and bond rotations of the octahedral and d(6) amido complexes TpRu(L)(L')(NHPh) (Tp = hydridotris(pyrazolyl)borate; L = L' = PMe(3) or P(OMe)(3), or L = CO and L' = PPh(3)): solid-state structures of [TpRu(PMe(3))(2)(NH(2)Ph)][OTf], [TpRu[P(OMe)(3)](2)(NH(2)Ph)][OTf], and TpRu[P(OMe)(3)](2)(NHPh).

    Science.gov (United States)

    Conner, David; Jayaprakash, K N; Gunnoe, T Brent; Boyle, Paul D

    2002-06-03

    It has been suggested that the reactivity of pi-donating ligands bound to late-transition-metal complexes is heightened due to high d-electron counts. Herein, the synthesis and characterization of the Ru(II) amine and Ru(II) amido complexes [TpRuL(2)(NH(2)Ph)][OTf] (OTf = trifluoromethanesulfonate) and TpRuL(2)(NHPh) (L = PMe(3) or P(OMe)(3)) are presented, including solid-state X-ray diffraction studies of [TpRu(PMe(3))(2)(NH(2)Ph)][OTf], [TpRu[P(OMe)(3)](2)(NH(2)Ph)][OTf], and TpRu[P(OMe)(3)](2)(NHPh). The pK(a)'s of the Ru(II) amine complexes and the previously reported [TpRu(CO)(PPh(3))(NH(2)Ph)](+) have been estimated to be comparable to that of malononitrile in methylene chloride. In addition, the impact of the filled dpi-manifold (i.e., Ru(II) and d(6) octahedral systems) on barriers to rotation of the Ru-NHPh moieties has been studied. For TpRu(PMe(3))(2)(NHPh) and TpRu[P(OMe)(3)](2)(NHPh), evidence for hindered rotation about the amido nitrogen and phenyl ipso carbon has been observed, and the relative N-C and Ru-N bond rotational barriers for the series of three amido complexes are discussed in terms of the pi-conflict.

  5. Digestibilidade e balanço de nitrogênio de rações com diferentes teores de proteína degradável no rúmen e milho moído como fonte de amido em ovinos Digestibility and nitrogen balance of sheep diets containing different levels of ruminal degradable protein and ground corn

    Directory of Open Access Journals (Sweden)

    Lúcia Maria Zeoula

    2006-10-01

    Full Text Available O objetivo neste trabalho foi avaliar a digestibilidade aparente de rações com diferentes teores de proteína degradável no rúmen (PDR e fonte de amido de baixa degradabilidade ruminal (milho moído em ovinos. Utilizaram-se quatro ovinos castrados, sem raça definida (SRD, com peso vivo médio de 38,5 kg, em um delineamento experimental quadrado latino 4 x 4. As quatro rações experimentais utilizadas foram compostas de 75% de volumoso (feno de aveia e 25% de concentrado à base de milho moído (MM, farelo de soja (FS, farelo de algodão (FA, farinha de peixe (FP, uréia e sal mineral, compostas com quatro teores de PDR (46, 50, 54 e 58% de PDR nas rações. Determinaram-se a digestibilidade aparente total dos nutrientes e o balanço de nitrogênio nos animais alimentados com as rações experimentais. Os consumos de MS, MO, PB, amido, FDN e FDA não diferiram entre as rações testadas. Da mesma forma, o nitrogênio ingerido (NI, o N excretado nas fezes e na urina, em g/dia, o balanço de nitrogênio (%NI e os coeficientes de digestibilidade da MS, MO, PB, FDN e FDA não diferiram entre as rações experimentais, sendo estimados valores médios de 31,68; 6,34; 11,31 g/dia e 44,27% NI, respectivamente, e de 71,90; 73,00; 79,70; 61,10; e 52,00%, respectivamente. Independentemente dos teores de PDR em rações contendo milho como fonte de amido de baixa degradabilidade ruminal, não houve efeitos sobre a digestibilidade aparente dos nutrientes e o balanço de nitrogênio em ovinos.Four castrated sheep averaging 38.5 kg of body weight were randomly assigned to a 4 x 4 Latin square to evaluate the apparent digestibility of nutrients and nitrogen balance (NB on diets containing different levels of rumen degradable protein (RDP: 46, 50, 54, and 58% and ground corn. The four experimental diets were composed by 75% of forage (oat hay and 25% of concentrate containing ground corn (GC, soybean meal (SM, cottonseed meal (CM, fish meal (FM, urea, and

  6. Estudo das propriedades de compósitos biodegradáveis de amido/glúten de milho/glicerol reforçados com fibras de sisal Study of properties of biodegradable composites of starch/gluten/glycerol reinforced with sisal fibers

    Directory of Open Access Journals (Sweden)

    Elisângela Corradini

    2008-01-01

    Full Text Available Neste estudo, fibras de sisal foram utilizadas como reforço para a matriz constituída de amido, glúten de milho e glicerol. O teor de fibra em relação a matriz variou de 5 a 30%. O processamento da matriz e dos compósitos foi realizado em um reômetro de torque Haake à 130 °C, 50 rpm por 10 minutos. As misturas obtidas foram moldadas por compressão à quente. As propriedades mecânicas; termodinâmico-mecânico (DMTA e de absorção de água foram investigadas em função do teor de fibras na matriz de amido/glúten de milho/glicerol. O aumento do conteúdo de fibra provocou uma melhoria nas propriedades mecânicas dos compósitos com relação à matriz. O compósito reforçado com 30% de fibra de sisal apresentou aumento no módulo de elasticidade e tensão na ruptura de aproximadamente de 560 e 162%, respectivamente e diminuição nos valores de elongação na ruptura de 81%. Os resultados obtidos por DMTA mostraram aumento progressivo do módulo de armazenamento (E' e diminuição do módulo de amortecimento (tan d com o aumento do teor de fibra, confirmando o efeito de reforço das fibras de sisal na matriz de amido/glúten de milho/glicerol. A incorporação das fibras na matriz também provocou diminuição da absorção de umidade e no coeficiente de difusão de água. A análise da morfologia dos compósitos mostrou boa dispersão das fibras na matriz.Biocomposites using starch/gluten/glycerol as matrix and sisal fibers were produced by melt-mixing in an intensive batch mixer connected to a torque rheometer at 130 °C. The samples were compression molded and than characterized by water absorption and mechanical test. In tensile test, the increasing in the Young's modulus and ultimate tensile strenght were respectively of aproximately 560 and 162% in relation to matrix, whereas elongation at break decreased. The storage modulus increased with increasing fiber content whereas tan d curves decreased, confirming the reinforcing

  7. Anatomia dos órgãos vegetativos de Dieffenbachia picta Schott (Araceae com ênfase na distribuição de cristais, laticíferos e grãos de amido Anatomy of the vegetative organs from Dieffenbachia picta Schott (Araceae with an emphasis on crystals, laticifers and starch grains

    Directory of Open Access Journals (Sweden)

    Leandro de Santis Ferreira

    2006-12-01

    Full Text Available A distribuição dos cristais, laticíferos e grãos de amido foi estudada nos órgãos vegetativos de Dieffenbachia picta Schott (Araceae, conhecida por comigo-ninguém-pode, por tais estruturas serem citadas como responsáveis pela irritação mecânica e química provocada pela planta. A anatomia da folha, do caule aéreo, do rizoma e da raiz foi descrita por meio de seções histológicas coradas com azul de toluidina. A natureza química dos cristais e a presença de lipídios, alcalóides, grãos de amido e proteínas foram verificadas por reagentes diversos. Drusas e ráfides de oxalato de cálcio, associadas a lipídios, alcalóides e proteínas, ocorreram no interior de células presentes no parênquima de todos os órgãos, no colênquima caulinar e nos meristemas da raiz. O tempo de dissolução dos cristais das folhas jovem e adulta foi semelhante, o do caule foi maior que o da folha e o do rizoma maior que o da raiz. Grãos de amido, associados a proteínas, ocorreram no clorênquima do caule aéreo (forma de bastonetes e rizoma (formas esférica e bastonete. Laticíferos ocorreram entremeando o colênquima e o parênquima; o látex continha ráfides, alcalóides e lipídios. Maior número de idioblastos cristalíferos e laticíferos foi observado no caule aéreo, sendo este, portanto, o órgão que mais representa perigo.We studied the distribution of crystals, laticifers and starch grains of the vegetative organs from dumb cane, Dieffenbachia picta Schott (Araceae, known in Brazil as "comigo-ninguém-pode" for such structures are meant to be responsible for mechanical and chemical irritation events carried out by the plant. We described the anatomy of leaves, aerial stems, rhizomes and roots with histological sections dyed in toluidine blue. We checked the chemical nature of crystals and the presence of lipids, alkaloids, starch grains and proteins with various reagents. Druses and calcium oxalate raphides - associated with lipids

  8. Primary Intraosseous Meningioma.

    Science.gov (United States)

    Chen, Thomas C

    2016-04-01

    Primary intraosseous meningiomas are a subtype of primary extradural meningiomas. They represent approximately two-thirds of extradural meningiomas and fewer than 2% of meningiomas overall. These tumors originate within the bones of the skull and can have a clinical presentation and radiographic differential diagnosis different from those for intradural meningiomas. Primary intraosseous meningiomas are classified based on location and histopathologic characteristics. Treatment is primarily surgical resection with wide margins if possible. Sparse literature exists regarding the use of adjuvant therapies. The literature regarding primary intraosseous meningiomas consists primarily of clinical case reports and case series. This literature is reviewed and summarized in this article.

  9. Hyperaldosteronism - primary and secondary

    Science.gov (United States)

    Primary and secondary hyperaldosteronism have common symptoms, including: High blood pressure High level of calcium in the blood Fatigue Headache Muscle weakness Numbness Paralysis that comes and goes

  10. Primary osteosarcoma of breast

    Science.gov (United States)

    Gull, Sadaf; Patil, Prashant; Spence, Roy AJ

    2011-01-01

    Primary osteosarcoma of breast is rare. The authors present a case of a 51-year-old female who was admitted with a large necrotising tumour involving the right breast. CT scan confirmed chest wall invasion along with a solitary lung metastasis. She underwent a primary mastectomy with chest wall reconstruction. Unfortunately 3 months later she developed local recurrence. PMID:22688473

  11. Using Primary Source Documents.

    Science.gov (United States)

    Mintz, Steven

    2003-01-01

    Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

  12. Primary Spinal Meningeal Melanocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Dong Ho [Dong-A University, Busan (Korea, Republic of)

    2009-12-15

    Primary meningeal melanocytic neoplasms are rare lesions that originate from leptomeningeal melanocytes. An intradural meningeal melanocytoma in the thoracic spine is less common than a malignant melanoma, which is its malignant counterpart. We report a case of a histopathologically confirmed primary intradural meningeal melanocytoma in the thoracic spine along with a literature.

  13. Using Primary Source Documents.

    Science.gov (United States)

    Mintz, Steven

    2003-01-01

    Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

  14. Bilateral primary writing tremor.

    Science.gov (United States)

    Jimenez-Jimenez; Cabrera-Valdivia; Orti-Pareja; Gasalla; Tallon-Barranco; Zurdo

    1998-11-01

    Primary writing tremor is a task-specific tremor that is considered to be unilateral. We report a 59-year-old man with a 5-year history of a typical primary writing tremor in the right hand who developed similar symptoms in the left hand. Copyright 1998 Lippincott Williams & Wilkins

  15. Transforming Primary Mathematics

    Science.gov (United States)

    Askew, Mike

    2011-01-01

    What is good mathematics teaching? What is mathematics teaching good for? Who is mathematics teaching for? These are just some of the questions addressed in "Transforming Primary Mathematics", a highly timely new resource for teachers which accessibly sets out the key theories and latest research in primary maths today. Under-pinned by findings…

  16. Primary health care.

    Science.gov (United States)

    Kitai, A

    1986-07-01

    Development of primary care in Japan in still relatively unorganized and unstructured. As mentioned above, the author describes some strengths and weaknesses of the Japanese primary care system. In addressing the weaknesses the following suggestions are offered for the Japanese primary care delivery system: Increase the number of emergency rooms for all day, especially on holidays and at night. Introduce an appointment system. Introduce an open system of hospitals. Coordinate with public hospitals and primary care clinics. Organize the referral system between private practitioners and community hospitals. Increase the number of paramedical staff. Strengthen group practice among primary care physicians. Increase the establishment of departments of primary care practice with government financial incentives to medical schools and teaching hospitals. Develop a more active and direct teaching role for primary care practice or family practice at undergraduate, graduate, and postgraduate levels. Improve and maintain present health insurance payment method, shifting from quantity of care to quality and continuity of care. Introduce formal continuing education. Introduce formal training programs of primary care and strengthen ambulatory care teaching programs.

  17. Amido no megagametófito de Araucaria angustifolia (Bert. O. Ktze: degradação durante a germinação e desenvolvimento do esporófito Starchy reserve of the megagametophyte of Araucaria angustifolia (Bert. O. Ktze: mobilization during germination and on the developing sporophyte

    Directory of Open Access Journals (Sweden)

    Rosa Maris Rosado

    1994-07-01

    Full Text Available O pinheiro brasileiro possui um diásporo de grandes dimensões, o pinhão, rico em reservas amiláceas. A mobilização dessas reservas pelo embrião foi quantificada em secções transversais do megagametófito, em cinco estágios de desenvolvimento da plântula, sob dois tratamentos, na luz e no escuro. Na luz, o consumo das reservas do megagametófito pela plântula é mais rápido do que no escuro e, existe uma tendência ao consumo do amido realizar-se primeiro na região do megagametófito próxima ao embrião.The parana pine has a very large dispore, the "pinhão", rich in starchy reserves. The mobilization of these reserves by the embryo was quantified in transversal sections of the megagametophyte, in five stages of seedling development, sampled in the light and in the darkness. The consuption of starch grains was in plantlets grown in light than those grown in darkness. There was a tendency to quicker use up of the the megagametophyte starch near to embryo.

  18. Primary myelofibrosis L.

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    L. M. Meshcheryakova

    2014-07-01

    Full Text Available Literature data of idiopathic myelofibrosis are presented: classification, diagnostic criteria, morphological and molecular features. Particular attention is given to therapy of various clinical forms of primary myelofibrosis.

  19. Primary meningeal rhabdomyosarcoma.

    Science.gov (United States)

    Palta, Manisha; Riedel, Richard F; Vredenburgh, James J; Cummings, Thomas J; Green, Scott; Chang, Zheng; Kirkpatrick, John P

    2011-01-01

    Primary meningeal rhabdomyosarcoma is a rare primary brain malignancy, with scant case reports. While most reports of primary intracranial rhabdomyosarcoma occur in pediatric patients, a handful of cases in adult patients have been reported in the medical literature. We report the case of a 44-year-old male who developed primary meningeal rhabdomyosarcoma. After developing episodes of right lower extremity weakness, word finding difficulty, and headaches, a brain magnetic resonance imaging (MRI) demonstrated a vertex lesion with radiographic appearance of a meningeal-derived tumor. Subtotal surgical resection was performed due to sagittal sinus invasion and initial pathology was interpreted as an anaplastic meningioma. Re-review of pathology demonstrated rhabdomyosarcoma negative for alveolar translocation t(2;13). Staging studies revealed no evidence of disseminated disease. He was treated with stereotactic radiotherapy with concurrent temozolamide to be followed by vincristine, actinomycin-D, and cyclophosphamide (VAC) systemic therapy.

  20. Primary infertility (image)

    Science.gov (United States)

    Primary infertility is a term used to describe a couple that has never been able to conceive a pregnancy ... to do so through unprotected intercourse. Causes of infertility include a wide range of physical as well ...

  1. Histoplasmosis - acute (primary) pulmonary

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000098.htm Histoplasmosis - acute (primary) pulmonary To use the sharing features on this page, please enable JavaScript. Acute pulmonary histoplasmosis is a respiratory infection that is caused by ...

  2. Primary Amoebic Meningoencephalitis

    National Research Council Canada - National Science Library

    Gupta, Ritu; Parashar, M K; Kale, Aditya

    2015-01-01

    Primary amoebic meningoencephalitis due to free living amoeba, also called 'brain eating amoeba', Naegleria fowleri, was detected in retroviral disease patient of 40 years who has history of using well water...

  3. Primary Meningeal Rhabdomyosarcoma

    Directory of Open Access Journals (Sweden)

    Manisha Palta

    2011-01-01

    Full Text Available Primary meningeal rhabdomyosarcoma is a rare primary brain malignancy, with scant case reports. While most reports of primary intracranial rhabdomyosarcoma occur in pediatric patients, a handful of cases in adult patients have been reported in the medical literature. We report the case of a 44-year-old male who developed primary meningeal rhabdomyosarcoma. After developing episodes of right lower extremity weakness, word finding difficulty, and headaches, a brain magnetic resonance imaging (MRI demonstrated a vertex lesion with radiographic appearance of a meningeal-derived tumor. Subtotal surgical resection was performed due to sagittal sinus invasion and initial pathology was interpreted as an anaplastic meningioma. Re-review of pathology demonstrated rhabdomyosarcoma negative for alveolar translocation t(2;13. Staging studies revealed no evidence of disseminated disease. He was treated with stereotactic radiotherapy with concurrent temozolamide to be followed by vincristine, actinomycin-D, and cyclophosphamide (VAC systemic therapy.

  4. ESTHETICS IN PRIMARY TEETH

    National Research Council Canada - National Science Library

    Mathew Renu Ann

    2013-01-01

    .... Esthetic restoration of primary anterior teeth can be especially challenging due to the small size of the teeth, close proximity of pulp to tooth surface, relatively thin enamel and surface area...

  5. Primary headache disorders.

    Science.gov (United States)

    Benoliel, Rafael; Eliav, Eli

    2013-07-01

    Primary headache disorders include migraine, tension-type headaches, and the trigeminal autonomic cephalgias (TACs). "Primary" refers to a lack of clear underlying causative pathology, trauma, or systemic disease. The TACs include cluster headache, paroxysmal hemicrania, and short-lasting neuralgiform headache attacks with conjunctival injection and tearing; hemicrania continua, although classified separately by the International Headache Society, shares many features of both migraine and the TACs. This article describes the features and treatment of these disorders.

  6. Teaching primary care obstetrics

    Science.gov (United States)

    Koppula, Sudha; Brown, Judith B.; Jordan, John M.

    2014-01-01

    Abstract Objective To explore the experiences and recommendations for recruitment of family physicians who practise and teach primary care obstetrics. Design Qualitative study using in-depth interviews. Setting Six primary care obstetrics groups in Edmonton, Alta, that were involved in teaching family medicine residents in the Department of Family Medicine at the University of Alberta. Participants Twelve family physicians who practised obstetrics in groups. All participants were women, which was reasonably representative of primary care obstetrics providers in Edmonton. Methods Each participant underwent an in-depth interview. The interviews were audiotaped and transcribed verbatim. The investigators independently reviewed the transcripts and then analyzed the transcripts together in an iterative and interpretive manner. Main findings Themes identified in this study include lack of confidence in teaching, challenges of having learners, benefits of having learners, and recommendations for recruiting learners to primary care obstetrics. While participants described insecurity and challenges related to teaching, they also identified positive aspects, and offered suggestions for recruiting learners to primary care obstetrics. Conclusion Despite describing poor confidence as teachers and having challenges with learners, the participants identified positive experiences that sustained their interest in teaching. Supporting these teachers and recruiting more such role models is important to encourage family medicine learners to enter careers such as primary care obstetrics. PMID:24627402

  7. Primary biliary cirrhosis: Report

    Directory of Open Access Journals (Sweden)

    Filipović Branka

    2002-01-01

    Full Text Available Chronic non-suppurative destructive cholangitis, the so-called primary biliary cirrhosis, is characterised by changes, which occur in intrahepatic bile ducts in early stages and in hepatic parenchyma as the disease progresses. The disease gradually evolves into the full-blown picture of biliary cirrhosis. Primary biliary cirrhosis predominantly affects women between 35 and 60 years of age in all social classes and in all races. Our patient was a woman, old 78 years old who admitted for treatment of hypertrophie cardiomyopathy. During the routine laboratory exploration signs of cholestasis were noted: higher values of alkaline phosphatase and gamma glutamyl transferase, combined with low level of platelets, probably of autoimmune origin. Hypercholesterolaemia (7.8 mmol/L associated with normal values of triglycerides was observed. The main criterion for establishing the diagnosis of primary biliary cirrhosis was the titer of antimito-chondrial antibodies in the serum, which was 1:640. At the same time, she had a urinary infection, caused by Escherichia coli, which confirmed possible relationship between primary biliary cirrhosis and occurence of some Gramm negative bacteria, reported elsewhere. On the other hand, biopsy of the liver was just an auxiliary method, serving for the confirmation of diagnosis. Ursodeoxycholic acid was used as the main drug in the therapy of primary biliary cirrhosis. This case of primary biliary cirrhosis is a worth report because of the comorbidity with cardiac symptoms, which were covering symptoms of hepatic disorder.

  8. Characterization of the Sweet Taste Receptor Tas1r2 from an Old World Monkey Species Rhesus Monkey and Species-Dependent Activation of the Monomeric Receptor by an Intense Sweetener Perillartine.

    Science.gov (United States)

    Cai, Chenggu; Jiang, Hua; Li, Lei; Liu, Tianming; Song, Xuejie; Liu, Bo

    2016-01-01

    Sweet state is a basic physiological sensation of humans and other mammals which is mediated by the broadly acting sweet taste receptor-the heterodimer of Tas1r2 (taste receptor type 1 member 2) and Tas1r3 (taste receptor type 1 member 3). Various sweeteners interact with either Tas1r2 or Tas1r3 and then activate the receptor. In this study, we cloned, expressed and functionally characterized the taste receptor Tas1r2 from a species of Old World monkeys, the rhesus monkey. Paired with the human TAS1R3, it was shown that the rhesus monkey Tas1r2 could respond to natural sugars, amino acids and their derivates. Furthermore, similar to human TAS1R2, rhesus monkey Tas1r2 could respond to artificial sweeteners and sweet-tasting proteins. However, the responses induced by rhesus monkey Tas1r2 could not be inhibited by the sweet inhibitor amiloride. Moreover, we found a species-dependent activation of the Tas1r2 monomeric receptors of human, rhesus monkey and squirrel monkey but not mouse by an intense sweetener perillartine. Molecular modeling and sequence analysis indicate that the receptor has the conserved domains and ligand-specific interactive residues, which have been identified in the characterized sweet taste receptors up to now. This is the first report of the functional characterization of sweet taste receptors from an Old World monkey species.

  9. Characterization of the Sweet Taste Receptor Tas1r2 from an Old World Monkey Species Rhesus Monkey and Species-Dependent Activation of the Monomeric Receptor by an Intense Sweetener Perillartine

    Science.gov (United States)

    Cai, Chenggu; Jiang, Hua; Li, Lei; Liu, Tianming; Song, Xuejie; Liu, Bo

    2016-01-01

    Sweet state is a basic physiological sensation of humans and other mammals which is mediated by the broadly acting sweet taste receptor-the heterodimer of Tas1r2 (taste receptor type 1 member 2) and Tas1r3 (taste receptor type 1 member 3). Various sweeteners interact with either Tas1r2 or Tas1r3 and then activate the receptor. In this study, we cloned, expressed and functionally characterized the taste receptor Tas1r2 from a species of Old World monkeys, the rhesus monkey. Paired with the human TAS1R3, it was shown that the rhesus monkey Tas1r2 could respond to natural sugars, amino acids and their derivates. Furthermore, similar to human TAS1R2, rhesus monkey Tas1r2 could respond to artificial sweeteners and sweet-tasting proteins. However, the responses induced by rhesus monkey Tas1r2 could not be inhibited by the sweet inhibitor amiloride. Moreover, we found a species-dependent activation of the Tas1r2 monomeric receptors of human, rhesus monkey and squirrel monkey but not mouse by an intense sweetener perillartine. Molecular modeling and sequence analysis indicate that the receptor has the conserved domains and ligand-specific interactive residues, which have been identified in the characterized sweet taste receptors up to now. This is the first report of the functional characterization of sweet taste receptors from an Old World monkey species. PMID:27479072

  10. Crystal structure and photoluminescence properties of a new monomeric copper(II) complex: bis(3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenolato-κ(3)O,N,O')copper(II).

    Science.gov (United States)

    Kocak, Cagdas; Oylumluoglu, Gorkem; Donmez, Adem; Coban, M Burak; Erkarslan, Ugur; Aygun, Muhittin; Kara, Hulya

    2017-05-01

    Copper(II)-Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric Cu(II) complex, [Cu(C10H11N2O4)2], has been synthesized by the reaction of 3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenol (H2L) and copper(II) acetate monohydrate in methanol, and was characterized by elemental analysis, UV and IR spectroscopies, single-crystal X-ray diffraction analysis and a photoluminescence study. The Cu(II) atom is located on a centre of inversion and is coordinated by two imine N atoms, two phenoxy O atoms in a mutual trans disposition and two hydroxy O atoms in axial positions, forming an elongated octahedral geometry. In the crystal, intermolecular O-H...O hydrogen bonds link the molecules to form a one-dimensional chain structure and π-π contacts also connect the molecules to form a three-dimensional structure. The solid-state photoluminescence properties of the complex and free H2L have been investigated at room temperature in the visible region. When the complex and H2L are excited under UV light at 349 nm, the complex displays a strong green emission at 520 nm and H2L displays a blue emission at 480 nm.

  11. A major barley allergen associated with baker's asthma disease is a glycosylated monomeric inhibitor of insect alpha-amylase: cDNA cloning and chromosomal location of the gene.

    Science.gov (United States)

    Mena, M; Sanchez-Monge, R; Gomez, L; Salcedo, G; Carbonero, P

    1992-11-01

    A 14.5 kDa barley endosperm protein that is a major allergen in baker's asthma disease, as previously shown by both in vitro (IgE binding) and in vivo tests, has been identified as a glycosylated monomeric member of the multigene family of inhibitors of alpha-amylase/trypsin from cereals. A cDNA encoding this allergen (renamed BMAI-1) has been isolated and characterized. The deduced sequence for the mature protein, which is 132 residues long, is identical in its N-terminal end to the 20 amino acid partial sequence previously determined from the purified allergen, and fully confirms that it is a member of the multigene family of cereal inhibitors. Southern-blot analysis of wheat/barley addition lines using the insert in the BMAI-1 cDNA clone as a probe, has led to the location of the allergen gene (Iam1) in barley chromosome 2, while another related member of this protein family, the barley dimeric alpha-amylase inhibitor BDAI-1 gene (Iad1) has been located in chromosome 6. Iam1 is the first member of this inhibitor family in cereals to be assigned to chromosome group 2, thus extending the dispersion of genes in the family to five out of the seven homology groups of chromosomes in wheat and barley (chromosomes 2, 3, 4, 6 and 7).

  12. Stereospecific approach to the synthesis of ring-A oxygenated sarpagine indole alkaloids. Total synthesis of the dimeric indole alkaloid P-(+)-dispegatrine and six other monomeric indole alkaloids.

    Science.gov (United States)

    Edwankar, Chitra R; Edwankar, Rahul V; Namjoshi, Ojas A; Liao, Xuebin; Cook, James M

    2013-07-05

    The first regio- and stereocontrolled total synthesis of the bisphenolic, bisquaternary alkaloid (+)-dispegatrine (1) has been accomplished in an overall yield of 8.3% (12 reaction vessels) from 5-methoxy-d-tryptophan ethyl ester (17). A crucial late-stage thallium(III) mediated intermolecular oxidative dehydrodimerization was employed in the formation of the C9-C9' biaryl axis in 1. The complete stereocontrol observed in this key biaryl coupling step is due to the asymmetric induction by the natural sarpagine configuration of the monomer lochnerine (6) and was confirmed by both the Suzuki and the oxidative dehydrodimerization model studies on the tetrahydro β-carboline (35). The axial chirality of the lochnerine dimer (40) and in turn dispegatrine (1) was established by X-ray crystallography and was determined to be P(S). Additionally, the first total synthesis of the monomeric indole alkaloids (+)-spegatrine (2), (+)-10-methoxyvellosimine (5), (+)-lochnerine (6), lochvinerine (7), (+)-sarpagine (8), and (+)-lochneram (11) were also achieved via the common pentacyclic intermediate 16.

  13. Other primary headaches

    Directory of Open Access Journals (Sweden)

    Anish Bahra

    2012-01-01

    Full Text Available The ′Other Primary Headaches′ include eight recognised benign headache disorders. Primary stabbing headache is a generally benign disorder which often co-exists with other primary headache disorders such as migraine and cluster headache. Primary cough headache is headache precipitated by valsalva; secondary cough has been reported particularly in association with posterior fossa pathology. Primary exertional headache can occur with sudden or gradual onset during, or immediately after, exercise. Similarly headache associated with sexual activity can occur with gradual evolution or sudden onset. Secondary headache is more likely with both exertional and sexual headache of sudden onset. Sudden onset headache, with maximum intensity reached within a minute, is termed thunderclap headache. A benign form of thunderclap headache exists. However, isolated primary and secondary thunderclap headache cannot be clinically differentiated. Therefore all headache of thunderclap onset should be investigated. The primary forms of the aforementioned paroxysmal headaches appear to be Indomethacin sensitive disorders. Hypnic headache is a rare disorder which is termed ′alarm clock headache′, exclusively waking patients from sleep. The disorder can be Indomethacin responsive, but can also respond to Lithium and caffeine. New daily persistent headache is a rare and often intractable headache which starts one day and persists daily thereafter for at least 3 months. The clinical syndrome more often has migrainous features or is otherwise has a chronic tension-type headache phenotype. Management is that of the clinical syndrome. Hemicrania continua straddles the disorders of migraine and the trigeminal autonomic cephalalgias and is not dealt with in this review.

  14. Primary hepatic carcinoid tumor

    Directory of Open Access Journals (Sweden)

    Gao Jinbo

    2011-11-01

    Full Text Available Abstract Primary hepatic carcinoid tumor is rare and poses a challenge for diagnosis and management. We presented a case of primary hepatic carcinoid tumor in a 53-year-old female with a complaint of right upper abdominal pain. Computer tomography scans revealed a hypervascular mass in segment 4 of the liver. An ultrasonography-guided biopsy showed a carcinoid tumor. No other lesions were found by the radiological investigations. Surgery resection was performed and histopathological examination revealed a primary hepatic carcinoid tumor. Three years later, recurrence was found and transcatheter arterial chemoembolization was performed. After transcatheter arterial chemoembolization, the patient has been free of symptom and had no radiological disease progression for over 6 months. Surgical resection combination with transcatheter arterial chemoembolization is effective to offer excellent palliation.

  15. Primary renal synovial sarcoma

    Directory of Open Access Journals (Sweden)

    Girish D. Bakhshi

    2012-03-01

    Full Text Available Primary Renal Sarcoma is rare tumor comprising only 1% of all renal tumours. Synovial sarcomas are generally deep-seated tumors arising in the proximity of large joints of adolescents and young adults and account for 5-10% of all soft tissue tumours. Primary synovial sarcoma of kidney is rare and has poor prognosis. It can only be diagnosed by immunohistochemistry. It should be considered as a differential in sarcomatoid and spindle cell tumours. We present a case of 33-year-old female, who underwent left sided radical nephrectomy for renal tumour. Histopathology and genetic analysis diagnosed it to be primary renal synovial sarcoma. Patient underwent radiation therapy and 2 years follow up is uneventful. A brief case report with review of literature is presented.

  16. Normocalcemic primary hyperparathyroidism

    Science.gov (United States)

    Bilezikian, John P.; Silverberg, Shonni J.

    2011-01-01

    SUMMARY Primary hyperparathyroidism is a common disorder of mineral metabolism characterized by incompletely regulated, excessive secretion of parathyroid hormone from one or more of the parathyroid glands. The historical view of this disease describes two distinct entities marked by two eras. When primary hyperparathyroidism was first discovered about 80 years ago, it was always symptomatic with kidney stones, bone disease and marked hypercalcemia. With the advent of the multichannel autoanalyzer about 40 years ago, the clinical phenotype changed to a disorder characterized by mild hypercalcemia and the absence of classical other features of the disease. We may now be entering a 3rd era in the history of this disease in which patients are being discovered with normal total and ionized serum calcium concentrations but with parathyroid hormone levels that are consistently elevated. In this article, we describe this new entity, normocalcemic primary hyperparathyroidism, a forme fruste of the disease. PMID:20485897

  17. Primary lymphoma of the brain

    Science.gov (United States)

    Brain lymphoma; Cerebral lymphoma; Primary lymphoma of the central nervous system; Lymphoma - brain ... The cause of primary brain lymphoma is not known. People with a weakened immune system are at high risk for primary lymphoma of the brain. ...

  18. Primary leptomeningeal lymphoma

    Science.gov (United States)

    Taylor, Jennie W.; Flanagan, Eoin P.; O'Neill, Brian P.; Siegal, Tali; Omuro, Antonio; DeAngelis, Lisa; Baehring, Joachim; Nishikawa, Ryo; Pinto, Fernando; Chamberlain, Marc; Hoang-Xuan, Khe; Gonzalez-Aguilar, Alberto; Batchelor, Tracy; Blay, Jean-Yves; Korfel, Agnieszka; Betensky, Rebecca A.; Lopes, Maria-Beatriz S.

    2013-01-01

    Objective: To evaluate clinical presentation, optimal diagnostic evaluation and treatment, and outcome in primary leptomeningeal lymphoma, a rare form of primary CNS lymphoma without parenchymal or systemic involvement. Methods: The International Primary CNS Lymphoma Collaborative Group, a multidisciplinary group of physicians with a particular interest in primary CNS lymphoma, retrospectively identified cases of lymphoma isolated to the leptomeninges as diagnosed by CSF cytology, flow cytometry, or biopsy, without systemic or parenchymal brain/spinal cord lymphoma or immunodeficiency. Results: Forty-eight patients were identified, with median age at diagnosis of 51 years and median Eastern Cooperative Oncology Group performance status of 2. Presenting symptoms were multifocal in 68%. Leptomeningeal enhancement was seen in 74% and CSF profile was abnormal in all cases. CSF cytology detected malignant lymphocytes in 67%. Flow cytometry identified monoclonal population in 80%, as did receptor gene rearrangement studies in 71%. Sixty-two percent had B-cell lymphoma, 19% T-cell, and 19% unclassified. Treatment varied and included fractionated radiotherapy (36%), systemic chemotherapy (78%), and intra-CSF chemotherapy (66%), with 66% receiving ≥2 modalities. Seventy-one percent had a favorable clinical response; ultimately, 44% received salvage treatment. Median overall survival was 24 months, with 11 patients still alive at 50 months follow-up. Conclusion: Primary leptomeningeal lymphoma is a rare form of primary CNS lymphoma. Patients usually present with multifocal symptoms, with evidence of leptomeningeal enhancement and diagnostic CSF analysis. Although treatment is highly variable, patients have a better prognosis than previously reported and a subset may be cured. PMID:24107866

  19. A human antibody to the CD4 binding site of gp120 capable of highly potent but sporadic cross clade neutralization of primary HIV-1.

    Directory of Open Access Journals (Sweden)

    Johannes S Gach

    Full Text Available Primary isolates of HIV-1 resist neutralization by most antibodies to the CD4 binding site (CD4bs on gp120 due to occlusion of this site on the trimeric spike. We describe 1F7, a human CD4bs monoclonal antibody that was found to be exceptionally potent against the HIV-1 primary isolate JR-FL. However, 1F7 failed to neutralize a patient-matched primary isolate, JR-CSF even though the two isolates differ by <10% in gp120 at the protein level. In an HIV-1 cross clade panel (n = 157, 1F7 exhibited moderate breadth, but occasionally achieved considerable potency. In binding experiments using monomeric gp120s of select resistant isolates and domain-swap chimeras between JR-FL and JR-CSF, recognition by 1F7 was limited by sequence polymorphisms involving at least the C2 region of Env. Putative N-linked glycosylation site (PNGS mutations, notably at position 197, allowed 1F7 to neutralize JR-CSF potently without improving binding to the cognate, monomeric gp120. In contrast, flow cytometry experiments using the same PNGS mutants revealed that 1F7 binding is enhanced on cognate trimeric Env. BN-PAGE mobility shift experiments revealed that 1F7 is sensitive to the diagnostic mutation D368R in the CD4 binding loop of gp120. Our data on 1F7 reinforce how exquisitely targeted CD4bs antibodies must be to achieve cross neutralization of two closely related primary isolates. High-resolution analyses of trimeric Env that show the orientation of glycans and polymorphic elements of the CD4bs that affect binding to antibodies like 1F7 are desirable to understand how to promote immunogenicity of more conserved elements of the CD4bs.

  20. Primary cutaneous leiomysarcoma

    Directory of Open Access Journals (Sweden)

    Shubhangi Vinayak Agale

    2011-01-01

    Full Text Available Primary cutaneous leiomyosarcoma of the skin is a rare soft tissue neoplasm, accounting for about 2-3% of all superficial soft tissue sarcomas. It arises between the ages of 50 and 70 years, and shows a greater predilection for the lower extremities. Clinically, it presents with solitary, well-circumscribed nodule and, microscopically, consists of fascicles of spindle-shaped cells with "cigar-shaped" nuclei. Local recurrence is known in this tumor. We document a case of primary cutaneous leiomyosarcoma in a 77-year-old man and discuss the histological features and immunohistochemical profile of this uncommon neoplasm.

  1. Bilateral Primary Intraocular Lymphoma

    Directory of Open Access Journals (Sweden)

    Mehrdad Karimi

    2011-01-01

    Full Text Available Purpose: To report a case of bilateral primary intraocular lymphoma. Case report: A 33-year-old man presented with bilateral blurred vision since two years ago. Examination revealed large keratic precipitates, anterior chamber reaction, posterior subcapsular cataracts, and vitreous infiltration. After a short trial of topical and periocular steroids, diagnostic 25-gauge pars plana vitrectomy was performed and cytologic evaluation of the aspirate confirmed a diagnosis of intraocular lymphoma. The patient was subsequently managed with intravitreal methotrexate in both eyes and responded favorably. Central nervous system workup for lymphoma was negative. Conclusion: Primary intraocular lymphoma should be considered in young adults suffering from chronic recalcitrant panuveitis.

  2. Melatonin for primary insomnia?

    Science.gov (United States)

    2009-07-01

    Melatonin, a hormone produced by the pineal gland, has a key role in regulating circadian rhythms, most importantly, the sleep-wake cycle. Melatonin's action has led to its being tried as a treatment for a wide range of sleep disorders, such as jet lag, primary insomnia, sleep-wake cycle disruption and sleep problems in children with neuro-developmental disorders. Until recently, it had not been licensed in the UK for any indication. Prolonged-release melatonin (Circadin - Lundbeck) has now been licensed as a treatment for primary insomnia. Here we consider whether this product has a place in the management of people with this condition.

  3. Desenvolvimento e avaliação da eficácia de filmes biodegradáveis de amido de mandioca com nanocelulose como reforço e com extrato de erva-mate como aditivo antioxidante Development and evaluation of the effectiveness of biodegradable films of cassava starch with nanocelulose as reinforcement and yerba mate extract as an additive antioxidant

    Directory of Open Access Journals (Sweden)

    Bruna Aparecida Souza Machado

    2012-11-01

    Full Text Available O objetivo do trabalho foi desenvolver uma embalagem biodegradável utilizando como matriz polimérica o amido de mandioca plastificada com glicerol e reforçada com a incorporação de nanocelulose da fibra de coco, bem como, avaliar o efeito da adição de um aditivo natural (erva-mate nas formulações de nanobiocompósitos com ação antioxidante. Os nanocristais de celulose (L/D=39 foram obtidos por hidrólise ácida com H2SO4 a 65%. Os filmes foram preparados por casting contendo 4,5 e 6,0% de amido, 0,5 e 1,5% de glicerol, 0,3% de nanocelulose e 20% de extrato de erva-mate. O armazenamento do azeite de dendê embalado com os filmes contendo o aditivo foi monitorado por 40 dias sob condições de oxidação acelerada (63%UR/30°C. Constatou-se que, à medida que aumentam as perdas de Polifenóis Totais nos filmes, ocorre um menor aumento do Índice de Peróxidos do produto embalado, demonstrando, assim, que, ao invés do produto, os compostos da embalagem é quem estão sofrendo oxidação. A incorporação de extrato de erva-mate não alterou as propriedades mecânicas e de barreira desses filmes.The objective was to develop biodegradable packaging using a polymer matrix as the cassava starch plasticized with glycerol and reinforced with the incorporation of nanocelulose of coconut fiber, as well as to evaluate the effect of the addition of an additive nature (yerba mate in nanobiocompósitos formulations with antioxidant action. The nanocrystal cellulose (L/D=39 were obtained by acid hydrolysis with 65% H2SO4. The films were prepared by casting containing 4.5 and 6.0% starch, 0.5 and 1.5% glycerol, 0.3% nanocelulose and 20% extract of yerba mate. The palm oil storage packed with films containing the additive was monitored for 40 days under conditions of accelerated oxidation (63%UR/30°C. It was found that as the losses increase polyphenol films, there is a smaller increase of the peroxide value of the packaged product, thus

  4. Fermentation and recovery of L-glutamic acid from cassava starch hydrolysate by ion-exchange resin column Produção de ácido L-glutâmico a partir de um hidrolisado de amido de mandioca usando resina de troca iônica

    Directory of Open Access Journals (Sweden)

    K. Madhavan Nampoothiri

    1999-07-01

    Full Text Available Investigations were carried out with the aim of producing L-glutamic acid from Brevibacterium sp. by utilizing a locally available starchy substrate, cassava (Manihot esculenta Crantz. Initial studies were carried out in shake flasks, which showed that even though the yield was high with 85-90 DE (Dextrose Equivalent value, the maximum conversion yield (~34% was obtained by using only partially digested starch hydrolysate, i.e. 45-50 DE. Fermentations were carried out in batch mode in a 5 L fermenter, using suitably diluted cassava starch hydrolysate, using a 85-90 DE value hydrolysate. Media supplemented with nutrients resulted in an accumulation of 21 g/L glutamic acid with a fairly high (66.3% conversation yield of glucose to glutamic acid (based on glucose consumed and on 81.74% theoretical conversion rate. The bioreactor conditions most conducive for maximum production were pH 7.5, temperature 30°C and an agitation of 180 rpm. When fermentation was conducted in fed-batch mode by keeping the residual reducing sugar concentration at 5% w/v, 25.0 g/L of glutamate was obtained after 40 h fermentation (16% more the batch mode. Chromatographic separation by ion-exchange resin was used for the recovery and purification of glutamic acid. It was further crystallized and separated by making use of its low solubility at the isoelectric point (pH 3.2.Pesquisas foram realizadas com o objetivo de produzir ácido glutâmico a partir de Brevibacterium sp. utilizando um substrato disponível na região, a mandioca (Manihot esculenta Crantz. Estudos iniciais, desenvolvidos em shaker, demonstraram que mesmo obtendo elevado rendimento com 85-90 DE (Dextrose Equivalent value, a taxa de conversão máxima (~34% foi obtida usando um hidrolisado de amido parcialmente digerido, i.e. 45-50 DE. As fermentações foram realizadas em um fermentador de 5 L, usando um hidrolisado de amido de mandioca adequadamente diluído, preparado à partir de um valor DE de 85-90. O

  5. Quantificação de açúcares solúveis totais, açúcares redutores e amido nos grãos verdes de cultivares de milho na colheita Quantification of total soluble sugars, reducing sugars and starch in immature kernels of corn cultivars

    Directory of Open Access Journals (Sweden)

    Fernanda Fátima Caniato

    2007-12-01

    Full Text Available O objetivo deste trabalho foi quantificar os teores de açúcares solúveis totais (AST, açúcares redutores (AR e amido em nove cultivares de milho colhidos no estádio verde, uma vez que estes influenciam diretamente o sabor, o aroma e a aceitação do consumidor. O experimento foi conduzido em Ponte Nova, MG, no ano agrícola 2002/2003. Para a determinação das características, foi retirada uma amostra de três espigas de cada unidade experimental. O ponto de colheita foi identificado por método empírico, quando o estilo-estigma se desprendia da espiga com facilidade. As cultivares apresentaram umidades diferentes no momento da colheita, variando de 56 a 64%. Não foi detectada diferença entre as cultivares quanto aos teores de AR, porém, P3232 e AG4051 apresentaram boa relação entre AR e AST, destacando-se para esta finalidade.Total soluble sugars (TSS, reducing sugars (RS, moisture and starch directly influence flavor and consumption. In this work, TSS, RS and starch were determined at harvest in young kernels of nine corn cultivars. The experiment was carried out in Ponte Nova, MG, Brazil. To determine chemical characters of young kernels a sample was obtained of three cobs from each experimental plot. Corn ears were harvested using an empirical method, when the silk was loose from the ear. Moisture varied among samples of different cultivars at harvest. Moisture content ranged from 56 to 64%. There were no differences among cultivars regarding RS. However, cultivars P3232 and AG4051 showed good RS to TSS ratio, being adequate for fresh consumption.

  6. Neurobiology in primary headaches

    DEFF Research Database (Denmark)

    Edvinsson, Lars; Uddman, Rolf

    2005-01-01

    , usually accompanied by nausea, vomiting, photophobia and/or phonophobia. A number of hypothesis have emerged to explain the specific causes of migraine. Current theories suggest that the initiation of a migraine attack involves a primary central nervous system (CNS) event. It has been suggested...

  7. Healthcare is primary.

    Science.gov (United States)

    Kumar, Raman

    2015-01-01

    India is undergoing a rapid transformation in terms of governance, administrative reforms, newer policy develoment, and social movements. India is also considered one of the most vibrant economies in the world. The current discourse in public space is dominated by issues such as economic development, security, corruption free governance, gender equity, and women safety. Healthcare though remains a pressing need of population; seems to have taken a backseat. In the era of decreasing subsidies and cautious investment in social sectors, the 2(nd) National Conference on Family Medicine and Primary Care 2015 (FMPC) brought a focus on "healthcare" in India. The theme of this conference was "Healthcare is Primary." The conference participants discussed on the theme of why healthcare should be a national priority and why strong primary care should remain at the center of healthcare delivery system. The experts recommended that India needs to strengthen the "general health system" instead of focusing on disease based vertical programs. Public health system should have capacity and skill pool to be able to deliver person centered comprehensive health services to the community. Proactive implementation of policies towards human resource in health is the need of the hour. As the draft National Health Policy 2015 is being debated, "family medicine" (academic primary care), the unfinished agenda of National Health Policy 2002, remains a priority area of implementation.

  8. Primary Pulmonary Hodgkin Lymphoma

    OpenAIRE

    Shumaila Tanveer; Ahmed El Damati; Ayman El Baz; Ahmed Alsayyah; Tarek ElSharkawy; Mohamed Regal

    2015-01-01

    Primary pulmonary Hodgkin lymphoma (PPHL) is a rare disease. Herein, we report a case of PPHL with diagnostic concerns encountered during initial evaluation which is of paramount importance to keep the differential diagnosis in cases with high index of sus- picion for this rare entity.

  9. Assembly of primary cilia

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Veland, Iben R; Schrøder, Jacob M

    2008-01-01

    in primary cilia assembly or function have been associated with a panoply of disorders and diseases, including polycystic kidney disease, left-right asymmetry defects, hydrocephalus, and Bardet Biedl Syndrome. Here we provide an up-to-date review focused on the molecular mechanisms involved in the assembly...

  10. Philosophy in Primary Schools?

    Science.gov (United States)

    White, John

    2012-01-01

    The article is a critical discussion of the aims behind the teaching of philosophy in British primary schools. It begins by reviewing the recent Special Issue of the "Journal of Philosophy of Education" Vol 45 Issue 2 2011 on "Philosophy for Children in Transition", so as to see what light this might throw on the topic just…

  11. Primary and Presidential Candidates

    DEFF Research Database (Denmark)

    Goddard, Joseph

    2012-01-01

    This article looks at primary and presidential candidates in 2008 and 2012. Evidence suggests that voters are less influenced by candidates’ color, gender, or religious observation than previously. Conversely, markers of difference remain salient in the imaginations of pollsters and journalists...

  12. Philosophy in Primary Schools?

    Science.gov (United States)

    White, John

    2012-01-01

    The article is a critical discussion of the aims behind the teaching of philosophy in British primary schools. It begins by reviewing the recent Special Issue of the "Journal of Philosophy of Education" Vol 45 Issue 2 2011 on "Philosophy for Children in Transition", so as to see what light this might throw on the topic just mentioned. The result…

  13. Primary cutaneous myoepithelial carcinoma

    DEFF Research Database (Denmark)

    Frost, Markus Winther; Steiniche, Torben; Damsgaard, Tine Engberg

    2013-01-01

    This study describes a case of primary myoepithelial carcinoma of the skin and reviews the available literature on this topic. Myoepitheliomas and carcinomas arise most frequently from myoepithelial cells within the salivary glands but are found in many anatomical locations. We documented a case...

  14. Multiple Primary Cancer Monograph

    Science.gov (United States)

    To identify groups of cancer survivors that are at increased risk for multiple primary cancers, investigators led an effort to provide the first comprehensive population-based analysis of the risk of subsequent cancer in the U.S., resulting in a monograph.

  15. Surgery of Primary Melanomas

    Energy Technology Data Exchange (ETDEWEB)

    Rutkowski, Piotr, E-mail: rutkowskip@coi.waw.pl; Zdzienicki, Marcin; Nowecki, Zbigniew I. [Soft Tissue/Bone Sarcoma and Melanoma Department, M. Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw (Poland); Akkooi, Alexander C. J. van [Erasmus University Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2010-05-11

    Surgery remains the mainstay of melanoma therapy, regardless of the tumor site. Only the early diagnosis combined with proper surgical therapy currently gives patients affected by this malignancy the chance for a full cure. The main goal of surgical therapy is to provide the local control of the disease and to secure long-term survival of the patient without reasonable functional and esthetic impairment. The recommended method of biopsy—excisional biopsy, as an initial diagnostic and, to some extent, therapeutic procedure—is performed under local anesthesia as an elliptical incision with visual clear margins of 1–3 mm and with some mm of subcutaneous tissue. The extent of radical excision of the primary tumor (or scar after excisional biopsy) is based on the histopathologic characteristics of the primary tumor and usually consists of 1–2 cm margins with primary closure. The philosophy behind conducted randomized clinical trials has been to find the most conservative surgical approach that is able to guarantee the same results as more demolitive treatment. This has been the background of the trials designed to define the correct margins of excision around a primary cutaneous melanoma. Much less definition can be dedicated to the surgical management of patients with non-cutaneous melanomas.

  16. Primary diffuse leptomeningeal gliosarcomatosis.

    Science.gov (United States)

    Moon, Ju Hyung; Kim, Se Hoon; Kim, Eui Hyun; Kang, Seok-Gu; Chang, Jong Hee

    2015-04-01

    Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare condition with a fatal outcome, characterized by diffuse infiltration of the leptomeninges by neoplastic glial cells without evidence of primary tumor in the brain or spinal cord parenchyma. In particular, PDLG histologically diagnosed as gliosarcoma is extremely rare, with only 2 cases reported to date. We report a case of primary diffuse leptomeningeal gliosarcomatosis. A 68-year-old man presented with fever, chilling, headache, and a brief episode of mental deterioration. Initial T1-weighted post-contrast brain magnetic resonance imaging (MRI) showed diffuse leptomeningeal enhancement without a definite intraparenchymal lesion. Based on clinical and imaging findings, antiviral treatment was initiated. Despite the treatment, the patient's neurologic symptoms and mental status progressively deteriorated and follow-up MRI showed rapid progression of the disease. A meningeal biopsy revealed gliosarcoma and was conclusive for the diagnosis of primary diffuse leptomeningeal gliosarcomatosis. We suggest the inclusion of PDLG in the potential differential diagnosis of patients who present with nonspecific neurologic symptoms in the presence of leptomeningeal involvement on MRI.

  17. Primary ectopic frontotemporal craniopharyngioma

    Science.gov (United States)

    Ortega-Porcayo, Luis Alberto; Ponce-Gómez, Juan Antonio; Martínez-Moreno, Mauricio; Portocarrero-Ortíz, Lesly; Tena-Suck, Martha Lilia; Gómez-Amador, Juan Luis

    2015-01-01

    Introduction Primary ectopic craniopharyngiomas have only rarely been reported. Craniopharyngiomas involve usually the sellar and suprasellar region, but can be originated from cell remnants of the obliterated craniopharyngeal duct or metaplastic change of andenohypophyseal cells. We present the first case of a primary ectopic frontotemporal craniopharyngioma. Presentation of case A 35-year old woman presented with a one-year history of headache and diplopia. MRI showed a large frontotemporal cystic lesion. Tumor resection was performed with a keyhole endoscopic frontal lateral approach. The pathological features showed an adamantinomatous craniopharyngioma with a cholesterol granuloma reaction. Discussion There have been reported different localizations for primary ectopic craniopharyngioma. Our case presented a lobulated frontotemporal cystic mass formed by a dense eosinophilic proteinaceous material dystrophic calcifications and cholesterol crystals, with epithelial remnants. No tumor regrowth was observed in the magnetic resonance image 27 months postoperatively. Conclusion Primary ectopic craniopharyngioma is a rare entity with a pathogenesis that remains uncertain. This is an unusual anatomic location associated with unique clinical findings. PMID:25725331

  18. Primary Episodic Ataxias

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-10-01

    Full Text Available The clinical and genetic diagnosis, genotype-phenotype correlations, pathophysiology and treatment of primary episodic ataxia syndromes are reviewed by researchers from Departments of Neurology, UCLA School of Medicine, Los Angeles, CA; National Hospital for Neurology, Queen Square, London, UK; Johns Hopkins University School of Medicine, Baltimore, MD; and University of Rochester School of Medicine, NY, USA.

  19. Primary cultures of astrocytes

    DEFF Research Database (Denmark)

    Lange, Sofie C; Bak, Lasse Kristoffer; Waagepetersen, Helle S;

    2012-01-01

    During the past few decades of astrocyte research it has become increasingly clear that astrocytes have taken a central position in all central nervous system activities. Much of our new understanding of astrocytes has been derived from studies conducted with primary cultures of astrocytes. Such ...

  20. Restoring primary anterior teeth.

    Science.gov (United States)

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen.

  1. Development of Broadly Neutralizing Antibodies and Their Mapping by Monomeric gp120 in Human Immunodeficiency Virus Type 1-Infected Humans and Simian-Human Immunodeficiency Virus SHIVSF162P3N-Infected Macaques

    Science.gov (United States)

    Jia, Manxue; Lu, Hong; Markowitz, Martin; Cheng-Mayer, Cecilia

    2016-01-01

    ABSTRACT To improve our understanding of the similarities and differences between neutralizing antibodies elicited by simian-human immunodeficiency virus (SHIV)-infected rhesus macaques and human immunodeficiency virus type 1 (HIV-1)-infected humans, we examined the plasma of 13 viremic macaques infected with SHIVSF162P3N and 85 HIV-1-infected humans with known times of infection. We identified 5 macaques (38%) from 1 to 2 years postinfection (p.i.) with broadly neutralizing antibodies (bnAbs) against tier 2 HIV-1. In comparison, only 2 out of 42 (5%) human plasma samples collected in a similar time frame of 1 to 3 years p.i. exhibited comparable neutralizing breadths and potencies, with the number increasing to 7 out of 21 (30%) after 3 years p.i. Plasma mapping with monomeric gp120 identified only 2 out of 9 humans and 2 out of 4 macaques that contained gp120-reactive neutralizing antibodies, indicating distinct specificities in these plasma samples, with most of them recognizing the envelope trimer (including gp41) rather than the gp120 monomer. Indeed, a total of 20 gp120-directed monoclonal antibodies (MAbs) isolated from a human subject (AD358) and a Chinese rhesus macaque (GB40) displayed no or limited neutralizing activity against tier 2 strains. These isolated MAbs, mapped to the CD4-binding site, the V3 loop, the inner domain, and the C5 region of gp120, revealed genetic similarity between the human and macaque immunoglobulin genes used to encode some V3-directed MAbs. These results also support the use of envelope trimer probes for efficient isolation of HIV-1 bnAbs. IMPORTANCE HIV-1 vaccine research can benefit from understanding the development of broadly neutralizing antibodies (bnAbs) in rhesus macaques, commonly used to assess vaccine immunogenicity and efficacy. Here, we examined 85 HIV-1-infected humans and 13 SHIVSF162P3N-infected macaques for bnAbs and found that, similar to HIV-1-infected humans, bnAbs in SHIV-infected macaques are also rare

  2. Influence of osmolarity of contrast medium and saline flush on computed tomography angiography: Comparison of monomeric and dimeric iodinated contrast media with different iodine concentrations at an identical iodine delivery rate

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Miori, E-mail: miori@mx6.et.tiki.ne.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Doi, Shoko, E-mail: s16024@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Shimizu, Junichiro, E-mail: s01163@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Lee, Ki-Ja, E-mail: s01173@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Iwasaki, Toshiroh, E-mail: bpag2180@cc.tuat.ac.j [Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8, Fuchu 183-8509 (Japan); Miyake, Yoh-Ichi, E-mail: miyake@obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Yamada, Kazutaka, E-mail: kyamada@obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan)

    2010-10-15

    Purpose: To evaluate the influence of osmolarity of iodinated contrast media and saline flush on the contrast effect in thoracic computed tomography angiography (CTA) at an identical iodine delivery rate (IDR). Materials and methods: Seven beagles were used in a cross-over experiment. The contrast media used were iohexol 350 mgI/ml (IOH350; osmolarity 844 mmol/kg) and iodixanol 320 mgI/ml (IDX320; osmolarity 290 mmol/kg). Each contrast medium was administered to groups with and without saline flush at 40.0 mgI/kg/s for all experiments. Dynamic CT scanning was performed at the ninth thoracic vertebra level. The peak value, area under the curve (AUC), and time to peak (TTP) were calculated from the time attenuation curves of the pulmonary artery and aorta. Results: There was no significant difference between IOH350 and IDX320 with or without saline flush in the peak values for the pulmonary artery and aorta. AUC was significantly higher in groups with saline flush for both contrast media and arteries (p < 0.05) with no significant difference between contrast media. TTP was significantly longer in groups with saline flush than without saline flush for both contrast media and arteries (p < 0.05), with no significant difference between contrast media. Conclusions: There were no significant differences in the contrast effects of monomeric IOH350 and dimeric IDX320 in thoracic CTA when used at an identical IDR. Moreover, saline flush prolonged the peak duration at 600 mgI/kg.

  3. Fluorescent visualisation of the hypothalamic oxytocin neurones activated by cholecystokinin-8 in rats expressing c-fos-enhanced green fluorescent protein and oxytocin-monomeric red fluorescent protein 1 fusion transgenes.

    Science.gov (United States)

    Katoh, A; Shoguchi, K; Matsuoka, H; Yoshimura, M; Ohkubo, J-I; Matsuura, T; Maruyama, T; Ishikura, T; Aritomi, T; Fujihara, H; Hashimoto, H; Suzuki, H; Murphy, D; Ueta, Y

    2014-05-01

    The up-regulation of c-fos gene expression is widely used as a marker of neuronal activation elicited by various stimuli. Anatomically precise observation of c-fos gene products can be achieved at the RNA level by in situ hybridisation or at the protein level by immunocytochemistry. Both of these methods are time and labour intensive. We have developed a novel transgenic rat system that enables the trivial visualisation of c-fos expression using an enhanced green fluorescent protein (eGFP) tag. These rats express a transgene consisting of c-fos gene regulatory sequences that drive the expression of a c-fos-eGFP fusion protein. In c-fos-eGFP transgenic rats, robust nuclear eGFP fluorescence was observed in osmosensitive brain regions 90 min after i.p. administration of hypertonic saline. Nuclear eGFP fluorescence was also observed in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) 90 min after i.p. administration of cholecystokinin (CCK)-8, which selectively activates oxytocin (OXT)-secreting neurones in the hypothalamus. In double transgenic rats that express c-fos-eGFP and an OXT-monomeric red fluorescent protein 1 (mRFP1) fusion gene, almost all mRFP1-positive neurones in the SON and PVN expressed nuclear eGFP fluorescence 90 min after i.p. administration of CCK-8. It is possible that not only a plane image, but also three-dimensional reconstruction image may identify cytoplasmic vesicles in an activated neurone at the same time.

  4. Hydrogen for fluorine exchange in C6F6 and C6F5H by monomeric [1,3,4-(Me3C)3C5H2]2CeH: experimental and computational studies.

    Science.gov (United States)

    Maron, Laurent; Werkema, Evan L; Perrin, Lionel; Eisenstein, Odile; Andersen, Richard A

    2005-01-12

    The net reaction of monomeric Cp'(2)CeH [Cp' = 1,3,4-(Me(3)C)(3)(C(5)H(2))] in C(6)D(6) with C(6)F(6) is Cp'(2)CeF, H(2), and tetrafluorobenzyne. The pentafluorophenylmetallocene, Cp'(2)Ce(C(6)F(5)), is formed as an intermediate that decomposes slowly to Cp'(2)CeF and C(6)F(4) (tetrafluorobenzyne), and the latter is trapped by the solvent C(6)D(6) as a [2+4] cycloadduct. In C(6)F(5)H, the final products are also Cp'(2)CeF and H(2), which are formed from the intermediates Cp'(2)Ce(C(6)F(5)) and Cp'(2)Ce(2,3,5,6-C(6)F(4)H) and from an unidentified metallocene of cerium and the [2+4] cycloadducts of tetra- and trifluorobenzyne with C(6)D(6). The hydride, fluoride, and pentafluorophenylmetallocenes are isolated and characterized by X-ray crystallography. DFT(B3PW91) calculations have been used to explore the pathways leading to the observed products of the exergonic reactions. A key step is a H/F exchange reaction which transforms C(6)F(6) and the cerium hydride into C(6)F(5)H and Cp'(2)CeF. This reaction starts by an eta(1)-F-C(6)F(5) interaction, which serves as a hook. The reaction proceeds via a sigma bond metathesis where the fluorine ortho to the hook migrates toward H with a relatively low activation energy. All products observed experimentally are accommodated by pathways that involve C-F and C-H bond cleavages.

  5. Acupuncture in primary care.

    Science.gov (United States)

    Mao, Jun J; Kapur, Rahul

    2010-03-01

    Acupuncture, an ancient traditional Chinese medical therapy, is used widely around the world. When practiced by a certified provider, it is safe and patients often find it calming and relaxing. Animal and human studies have found a physiologic basis for acupuncture needling in that it affects the complex central and peripheral neurohormonal network. Although it is unclear whether acupuncture is beneficial over sham/placebo acupuncture, acupuncture care yields clinically relevant short- and long-term benefits for low back pain, knee osteoarthritis, chronic neck pain, and headache. The integration of acupuncture into a primary care setting also appears to be cost-effective. The practice of acupuncture in primary care requires rigorous training, financial discipline, and good communication skills. When done correctly, acupuncture is beneficial for both patients and providers.

  6. Cancer of unknown primary

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Yderstræde, Knud Bonnet; Gerke, Oke

    2017-01-01

    Cancer of unknown primary (CUP) ranges within top 10 cancers in both incidence and mortality. As primary identification is crucial to choosing treatment, guidelines on CUP emphasize the diagnostic strategy. Whether guidelines are complied with, or if they are indeed helpful, is however unclear. We...... to procedures and patient survival. The cohort was investigated in terms of validity of diagnosis through cross-referencing with the Cancer Registry (CR), which served as gold standard for cancer diagnoses and patients' cancer histories.The NPR cohort consisted of 542 patients (275 males, 264 females) of whom...... after 4 years.The validity of a CUP diagnosis in NPR was low when using data from CR as reference. More than half the suspected CUP patients had a previous cancer diagnosis with CUP being the most frequent. Patients were diagnosed in compliance with guidelines indicating high external validity, but less...

  7. [Basics of primary immunodeficiencies].

    Science.gov (United States)

    Hernández-Martínez, Claudia; Espinosa-Rosales, Francisco; Espinosa-Padilla, Sara Elva; Hernández-Martínez, Ana Rosa; Blancas-Galicia, Lizbeth

    2016-01-01

    Primary immunodeficiencies (PID) are a heterogeneous group of inherited disorders, the etiology are the defects in the development or function of the immune system. The principal PID manifestations are the infections in early age, malignancy and diseases of immune dysregulation as autoimmunity and allergy. PIDs are genetics disorders and most of them are inherited as autosomal recessive, also this group of diseases is more prevalent in males and in childhood. The antibody immunodeficiency is the PID more common in adults. The more frequent disorders are the infections in the respiratory tract, abscesses, candidiasis, diarrhea, BCGosis etc. Initial approach included a complete blood count and quantification of immunoglobulins. The delay in diagnosis could be explained due to a perception that the recurrent infections are normal process or think that they are exclusively of childhood. The early diagnosis of PID by primary care physicians is important to opportune treatment and better prognosis.

  8. Primary hyperparathyroidism and nephrolithiasis.

    Science.gov (United States)

    Vestergaard, Peter

    2015-05-01

    Calcifications in the kidneys may occur in the parenchyma (nephrocalcinosis), pelvis renis (nephrolithiasis) or ureters (ureterolithiasis). Several factors may protect against stone formation or promote precipitation of stones. Most stones contain calcium, and the hypercalciuria seen in primary hyperparathyroidism is a contributing factor to stone formation in the kidneys and urinary tract. In early case series, renal stone formation was frequent, whereas the proportion of patients with symptomatic renal stones has declined in recent years. However, a substantial proportion of patients presents with asymptomatic nephrocalcinosis or nephrolithiasis. Before diagnosis and treatment of primary hyperparathyroidism, renal stone events are more frequent than in the general population. However, even after surgical cure, an increased rate of renal stone events may be seen. This may to some extent be the result of stones or calcifications already present at the time of diagnosis or sequelae to prior stones such as infections or ureter strictures.

  9. Primary renal hydatidosis

    Directory of Open Access Journals (Sweden)

    Johnsy Merla Joel

    2016-01-01

    Full Text Available Echinococcosis or hydatidosis caused by the tapeworm, Echinococcus granulosus, has the highest prevalence in endemic regions and sheep farming areas. The most common organ involved is the liver (50–75% followed by the lungs (15–20% and other organs (10–20%. Primary involvement of the kidney without the involvement of the liver and lungs, i.e., isolated renal hydatid disease is extremely rare even in endemic areas. The incidence of renal echinococcosis is 2–4%. Renal hydatid cysts usually remain asymptomatic for many years and are multiloculated. A 63-year-old male presented with left loin pain. Computed tomography scan abdomen revealed a presumptive diagnosis of renal hydatid disease. The nephrectomy specimen received in histopathology confirmed the diagnosis. We describe a rare case of primary renal hydatidosis.

  10. [Primary care in France].

    Science.gov (United States)

    Sánchez-Sagrado, T

    2016-01-01

    The poor planning of health care professionals in Spain has led to an exodus of doctors leaving the country. France is one of the chosen countries for Spanish doctors to develop their professional career. The French health care system belongs to the Bismarck model. In this model, health care system is financed jointly by workers and employers through payroll deduction. The right to health care is linked to the job, and provision of services is done by sickness-funds controlled by the Government. Primary care in France is quite different from Spanish primary care. General practitioners are independent workers who have the right to set up a practice anywhere in France. This lack of regulation has generated a great problem of "medical desertification" with problems of health care access and inequalities in health. French doctors do not want to work in rural areas or outside cities because "they are not value for money". Medical salary is linked to professional activity. The role of doctors is to give punctual care. Team work team does not exist, and coordination between primary and secondary care is lacking. Access to diagnostic tests, hospitals and specialists is unlimited. Duplicity of services, adverse events and inefficiencies are the norm. Patients can freely choose their doctor, and they have a co-payment for visits and hospital care settings. Two years training is required to become a general practitioner. After that, continuing medical education is compulsory, but it is not regulated. Although the French medical Health System was named by the WHO in 2000 as the best health care system in the world, is it not that good. While primary care in Spain has room for improvement, there is a long way for France to be like Spain. Copyright © 2015 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Primary care for refugees.

    Science.gov (United States)

    Eckstein, Barbara

    2011-02-15

    Over the past decade, at least 600,000 refugees from more than 60 different countries have been resettled in the United States. The personal history of a refugee is often marked by physical and emotional trauma. Although refugees come from many different countries and cultures, their shared pattern of experiences allows for some generalizations to be made about their health care needs and challenges. Before being accepted for resettlement in the United States, all refugees must pass an overseas medical screening examination, the purpose of which is to identify conditions that could result in ineligibility for admission to the United States. Primary care physicians have the opportunity to care for members of this unique population once they resettle. Refugees present to primary care physicians with a variety of health problems, including musculoskeletal and pain issues, mental and social health problems, infectious diseases, and longstanding undiagnosed chronic illnesses. Important infectious diseases to consider in the symptomatic patient include tuberculosis, parasites, and malaria. Health maintenance and immunizations should also be addressed. Language barriers, cross-cultural medicine issues, and low levels of health literacy provide additional challenges to caring for this population. The purpose of this article is to provide primary care physicians with a guide to some of the common issues that arise when caring for refugee patients.

  12. Primary stabbing headache.

    Science.gov (United States)

    Pareja, Juan A; Sjaastad, Ottar

    2010-01-01

    Primary stabbing headache is characterized by transient, cephalic ultrashort stabs of pain. It is a frequent complaint with a prevalence of 35.2%, a female preponderance, and a mean age of onset of 28 years (Vågå study). Attacks are generally characterized by moderate to severe, jabbing or stabbing pain, lasting from a fraction of a second to 3s. Attack frequency is generally low, with one or a few attacks per day. The paroxysms generally occur spontaneously, during daytime. Most patients exhibit a sporadic pattern, with an erratic, unpredictable alternation between symptomatic and non-symptomatic periods. Paroxysms are almost invariably unilateral. Temporal and fronto-ocular areas are most frequently affected. Attacks tend to move from one area to another, in either the same or the opposite hemicranium. Jabs may be accompanied by a shock-like feeling and even by head movement - "jolts" -or vocalization. On rare occasions, conjunctival hemorrhage and monocular vision loss have been described as associated features. Primary stabbing headache may concur, synchronously or independently, with other primary headaches. In contrast to what is the case in adults, in childhood it is not usually associated with other headaches. Treatment is rarely necessary. Indomethacin, 75-150 mg daily, may seem to be of some avail. Celecoxib, nifedipine, melatonin, and gabapentin have been reported to be effective in isolated cases and small series of patients. The drug studies need corroboration. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Achieving Value in Primary Care: The Primary Care Value Model.

    Science.gov (United States)

    Rollow, William; Cucchiara, Peter

    2016-03-01

    The patient-centered medical home (PCMH) model provides a compelling vision for primary care transformation, but studies of its impact have used insufficiently patient-centered metrics with inconsistent results. We propose a framework for defining patient-centered value and a new model for value-based primary care transformation: the primary care value model (PCVM). We advocate for use of patient-centered value when measuring the impact of primary care transformation, recognition, and performance-based payment; for financial support and research and development to better define primary care value-creating activities and their implementation; and for use of the model to support primary care organizations in transformation.

  14. Localization of primary aldosteronism

    Energy Technology Data Exchange (ETDEWEB)

    Pagny, J.Y.; Chatellier, G.; Raynaud, A.; Plouin, P.F.; Corvol, P.

    1988-01-01

    After diagnosis of primary aldosteronism on the basis of biochemical evidence, the detection of the tumour is of crucial importance in the management of the disease. The efficacy of CT-Scan, Iodo-Cholesterol Scintigraphy, digitalized phlebography, adrenal vein sampling for steroid measurements (AVS), and Nuclear Magnetic Resonance (NMR) in 160 hypertensive patients with primary aldosteronism was reviewed. Diagnosis of Conn's adenoma (n=96) or Adrenal Hyperplasia (n=40) was confirmed by surgery or at least two concordant tumour localization tests. Scintigraphy gave a correct diagnosis in 53% of the 51 exams, CT-Scan in 82% of the 85 exams, and phlebography in 79% of 61 exams. Plasma Aldosterone/Cortisol ratio was 5 times higher on the side of adenoma in 55% of the 47 cases but this ratio was also present in 23% of 22 patients with adrenal hyperplasia. Each procedure exhibited few false positive and false negative cases. NMR performed in 15 patients with Conn's adenoma identified all the cases. But tumours displayed a signal close to the liver signal and identical to the normal adrenal. These results and the risk of invasive procedure failure of catheterization of the right adrenal vein (n=6) and adrenal haematoma (n=2) lead to propose a schema of exploration of patients with primary aldosteronism. The CT-Scan could be performed at the first step once the biological diagnosis confirmed. Phlebography and AVS will be performed only if tumour was less than 1 cm at the CT-Scan despite important biological abnormalities. This schema requires to be validated by a prospective evaluation.

  15. Bilateral primary breast lymphoma

    Institute of Scientific and Technical Information of China (English)

    Jung Im Yi; Byung Joo Chae; Ja Seong Bae; Bong Joo Kang; Ahwon Lee; Byung Joo Song; Sang Seol Jung

    2010-01-01

    @@ Primary breast lymphoma (PBL) is rare, accounting for 0.04%-0.50% of breast malignancies and 1.7% of extranodal lymphoma.1,2 The originally described diagnostic criteria for PBL2 remains the standard definition for this disease. These criteria are breast location as the clinical site of presentation, absence of history of previous lymphoma or evidence of widespread disease at diagnosis, close association of lymphoma with breast tissue in pathologic specimens, and involvement of ipsilateral lymph nodes if they develop simultaneously with PBL.

  16. Primary Prevention With Statins

    DEFF Research Database (Denmark)

    Mortensen, Martin B; Afzal, Shoaib; Nordestgaard, Børge G

    2015-01-01

    BACKGROUND: Guidelines recommend initiating primary prevention for atherosclerotic cardiovascular disease (ASCVD) with statins based on absolute ASCVD risk assessment. Recently, alternative trial-based and hybrid approaches were suggested for statin treatment eligibility. OBJECTIVES: This study...... prevention of ASCVD with statins was superior to the trial-based and hybrid approaches. Our results indicate that the ACC/AHA guidelines will prevent more ASCVD events than the trial-based and hybrid approaches, while treating fewer people compared with the trial-based approach....

  17. PRIMARY SCHOOL TEACHER

    CERN Multimedia

    Madeleine Dittus

    2002-01-01

    For January 2003, the A.P.E.G. has an opening for a primary school teacher in the German national language program. The position requires one afternoon of teaching (13:30 till 16:30) every Tuesday at the Collège in Prévessin. The candidate should be a native speaker of German and have some knowledge of French. If you are interested, please send your CV, a copy of your diploma, and a short letter of motivation, until December 9th, to the following address. Madeleine Dittus Présidente A.P.E.G. 5, La vie Destraz 01630 St. Genis-Pouilly (France)

  18. Primary Pancreatic Lymphomas

    Directory of Open Access Journals (Sweden)

    Muhammad Wasif Saif

    2006-05-01

    Full Text Available Extranodal non-Hodgkin’s lymphomas (NHLs represent up to 30-40% of all NHL cases. The gastrointestinal tract is the most commonly involved extranodal site; accounting for about half of such cases [1]. Stomach and the small intestine constitute the most common gastrointestinal sites. Secondary invasion of the pancreas from contiguous, retroperitoneal lymph node disease is the prevalent mode of involvement. Secondary involvement of the pancreas from the duodenum or adjacent peripancreatic lymphadenopathy is well-known. Primary pancreatic lymphoma (PPL is an extremely rare disease [2]. PPL can present as an isolated mass mimicking pancreatic carcinoma. However, unlike carcinomas, PPL are potentially treatable [3].

  19. PRIMARY CARIES: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2012-01-01

    Full Text Available Primary caries is an initial lesions produced by direct extension from an external surface. Dental caries is called as tooth decay or a cavity is a disease in which bacterial processes changes carbohydrate to acid which than dematerializes the hard tooth structure like enamel, dentin and cementum. Streptococcus mutans and Lactobacillus are the bacteria responsible for the dental caries by acid production. This article throws light on the dental caries disease, its sign and symptoms, treatment and prevention of it. A review of some patents on dental caries is also provided that summarizes the recent technical advancements taken place in this area.

  20. Primary leptomeningeal melanoma.

    Science.gov (United States)

    Xie, Zhao-Yu; Hsieh, Kevin Li-Chun; Tsang, Yuk-Ming; Cheung, Wing-Keung; Hsieh, Chen-Hsi

    2014-06-01

    Primary melanoma of the central nervous system is a rare melanocytic tumor typically located in the leptomeninges. We report a 57-year-old woman with an intracranial leptomeningeal melanoma who presented with myoclonic seizures. Brain CT scan and MRI revealed a hemorrhagic intracranial tumor. The tumor was completely removed and leptomeningeal melanoma was proven pathologically. Follow-up imaging studies up to 19 months showed no recurrence of the disease. Here we present radiological, gross, and pathological images of leptomeningeal melanoma, discuss its characteristics, and review the relevant literature.

  1. Teacher of primary English

    CERN Multimedia

    2003-01-01

    Part-time teacher of primary English needed for September 2003 to teach English National Curriculum (KS2) and NLS to mother tongue or good second language English-speakers aged 7-10. 4 hours contact time per week, team planning, marking and meetings. Candidates should be English mother tongue qualified teachers, confident, flexible classroom practitioners and team players. For further details and how to apply see http://enpferney.org/staff_vacancies.htm English National Programme, Lycée International, Ferney-Voltaire (http://enpferney.org/)

  2. Epigenetics and primary care.

    Science.gov (United States)

    Wright, Robert; Saul, Robert A

    2013-12-01

    Epigenetics, the study of functionally relevant chemical modifications to DNA that do not involve a change in the DNA nucleotide sequence, is at the interface between research and clinical medicine. Research on epigenetic marks, which regulate gene expression independently of the underlying genetic code, has dramatically changed our understanding of the interplay between genes and the environment. This interplay alters human biology and developmental trajectories, and can lead to programmed human disease years after the environmental exposure. In addition, epigenetic marks are potentially heritable. In this article, we discuss the underlying concepts of epigenetics and address its current and potential applicability for primary care providers.

  3. Primary Sclerosing Cholangitis

    Directory of Open Access Journals (Sweden)

    A Stiehl

    2000-01-01

    Full Text Available Primary sclerosing cholangitis (PSC is a chronic cholestatic liver disease characterized by fibrosing inflammation and obliteration of intra- and/or extrahepatic bile ducts. The disease is one of the most common cholestatic diseases in adults and is diagnosed with increasing frequency. It is very often associated with ulcerative colitis. Patients with PSC have an increased incidence of bile duct carcinomas, and those with ulcerative colitis also have an increased incidence of colonic carcinomas. In end-stage disease, liver transplantation is the treatment of choice. Immunosuppressive treatment has little effect. Ursodeoxycholic acid (UDCA, which has been shown to improve liver histology and survival in patients with primary biliary cirrhosis, has a beneficial effect in PSC, provided that patients who develop major duct stenoses are treated endoscopically. The aim is to treat patients as early as possible to prevent progression to the advanced stages of the disease. During treatment with UDCA, stenoses of major ducts may develop, and early endoscopic dilation is highly effective. Because UDCA treatment improves but does not cure cholestatic liver diseases, permanent treatment seems to be necessary. Such prolonged treatment with UDCA may be recommended because, until now, no side effects have been reported. In patients with end-stage disease, UDCA is not effective and liver transplantation is indicated.

  4. Primary pediatric gastrointestinal lymphoma

    Directory of Open Access Journals (Sweden)

    Ranjana Bandyopadhyay

    2011-01-01

    Full Text Available Background: Primary non-Hodgkin′s lymphoma (NHL of the gastrointestinal (GI tract is the most common extranodal lymphoma in pediatric age group. Yet, the overall incidence is very low. The rarity of the disease as well as variable clinical presentation prevents early detection when the possibility of cure exists. Materials and Methods: We studied six cases of primary GI NHL in pediatric age group with reference to their clinical presentation, anatomic distribution and histopathologic characteristics. Results: All were males except one. Intestinal obstruction was the presenting feature in 50%. Half the cases showed ileocaecal involvement, while large bowel was involved in 16%. Histology showed four cases of diffuse large B-cell lymphoma (DLBCL, one case of Burkitt lymphoma, and one Burkitt-like lymphoma. Immunohistochemistry for Tdt, CD20, CD3, CD30, bcl2, bcl6 confirmed the morphological diagnosis. Conclusion: Pediatric GI lymphoma commonly involves the ileocaecal region and presents with intestinal obstruction. A higher prevalence of DLBCL is found compared to other series. A high proliferative index is useful in differentiating Burkitt-like lymphoma from DLBCL.

  5. Primary pulmonary choriocarcinoma

    Science.gov (United States)

    Snoj, Ziga; Kocijancic, Igor

    2017-01-01

    Abstract Background The aim of the study was to establish whether there are different clinical entities of primary pulmonary choriocarcinoma (PPC) that deserve different diagnostic approach and the most optimal treatment. Patients and methods A systematic review with PubMed search was conducted to identify studies that reported cases of PPC. The eligibility criteria were histological diagnosis of pulmonary choriocarcinoma and thorough examination of the reproductive organs to exclude potential primary choriocarcinoma in the gonads. Furthermore, to illustrate the review we additionally present a patient referred at our institution. Results 55 cases (17 men) were included in the review with a median age of 34 years. Women with the history of gestational event showed better survival outcome than women without the history of gestational event. Patients treated with combined modality treatment (surgery and chemotherapy) survived longer than the patients without combined modality treatment. Furthermore, multivariate analysis of prognostic factors showed that the combined modality treatment had independent prognostic significance. Size of the tumour showed significant prognostic influence in univariate and multivariate analysis. Conclusions PPC is an extreme rarity with variable clinical characteristics and outcome. It is important to capture and treat patients in the early stages of the disease. Women with the history of gestational event may show better survival, therefore genetic examination could help us to predict patient’s prognosis. Surgery followed by adjuvant chemotherapy appears to represent the best treatment for PPC.

  6. Methotrexate for primary biliary cirrhosis

    DEFF Research Database (Denmark)

    Giljaca, Vanja; Poropat, Goran; Stimac, Davor;

    2010-01-01

    Methotrexate has been used to treat patients with primary biliary cirrhosis as it possesses immunosuppressive properties. The previously prepared version of this review from 2005 showed that methotrexate seemed to significantly increase mortality in patients with primary biliary cirrhosis. Since...

  7. Genetics Home Reference: primary myelofibrosis

    Science.gov (United States)

    ... Other Diagnosis and Management Resources (3 links) Merck Manual Professional Version: Primary Myelofibrosis Myeloproliferative Neoplasm (MPN) Research Foundation: Primary Myelofibrosis (PMF) National Organization for Rare Disorders (NORD) Physician Guide General Information ...

  8. Bezafibrate for primary biliary cirrhosis

    DEFF Research Database (Denmark)

    Rudic, Jelena S; Poropat, Goran; Krstic, Miodrag N;

    2012-01-01

    Treatment of primary biliary cirrhosis is complicated. There are studies suggesting that bezafibrate, alone or in combination with ursodeoxycholic acid (UDCA), is effective in the treatment of primary biliary cirrhosis, but no systematic review has summarised the evidence yet....

  9. Manipulation of peptide conformations by fine-tuning of the environment and/or the primary sequence.

    Science.gov (United States)

    Li, S C; Kim, P K; Deber, C M

    1995-06-01

    The widely observed phenomenon that peptides are capable of adopting multiple conformations in different environments suggests that secondary structure formation in a peptide segment is a process involving not only the peptide itself but also the surrounding solvent media. The influence of the primary sequence and the molecular environment on peptide conformations are now investigated using synthetic peptides of amino acid sequence H2N-(Ser-Lys)2-Ala-X-Gly-Ala-X-Gly-Trp-Ala-X-Gly-(Lys-Ser)3-OH, where X = Ile or Val. These two peptides, namely 3I (X = Ile) and 3V (X = Val), are found to lack defined secondary structure in aqueous buffer. However, discrete conformational states, e.g., alpha-helices and beta-sheets, are readily generated and interconverted for both peptides when the buffer is modulated with the addition of methanol, sodium dodecyl sulfate (SDS) micelles, or phospholipid vesicles. The role of the primary sequence in affecting peptide conformations is manifested in that peptides 3I and 3V, which differ respectively in their content of beta-branched Ile or Val residues, differ in their secondary structures at monomeric concentrations in 2 mM SDS and in mixed lipid vesicles of phosphatidic acid and phosphatidylcholine. The overall results suggest that peptide segments can be conformationally flexible entities poised to react to minor modulation in either the molecular environment or the primary sequence, a circumstance that may be relevant to protein functioning and folding.

  10. 聚酰胺一胺树形分子的合成及其包覆的CdSe@CdS核壳结构量子点的性能研究%Synthesis of Poly(amido amine) Dendrimers and Property of Its Capped CdSe@CdS Core-shell Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    靳玉娟; 罗运军; 李国平

    2012-01-01

    以乙二胺和丙烯酸甲酯为原料,采用扩散法合成了不同端基类型不同代数的聚酰胺-胺(PAMAM)树形分子,并用红外光谱进行表征;以G5.0-NHzPAMAM树形分子为模板,以二甲基亚砜为溶剂,在常温下制备了稳定的PAMAM树形分子包覆的CdSe@CdS核壳结构量子点,并用紫外-可见吸收光谱和荧光发射光谱进行表征。结果表明,适当厚度CdS的包覆修饰可以有效提高CdSe量子点的发光性能;与单一组分的CdSe量子点相比,CdSe@,CdS核壳结构量子点的相对荧光强度最大提高约123%。%Poly(amido amine)(PAMAM) dendrimers with different terminal groups and generations were synthesized from ethylene amine and methyl acrylate via diffusion method, and the product was characterized using infrared spectra. PAMAM capped CdSe@CdS core-shell structure quantum dots was prepared taking GS. 0-NH2 PAMAM as templates at room temperature in dimethyl sulfoxide(DMSO) and characterized using UV-Vis absorption spectra and photoluminescence(PL) emission spectra. The coating of CdS on the surface of CdSe quantum dots was confirmed an effective method of enhancing photoluminescence property of CdSe quantum dots. Compared with neat CdSe quantum dots, the PL intensity of CdSe@CdS quantum dots was enhanced by 123 G.

  11. 含氨基膦酸螯合树脂的合成及其在铀提取中的性能研究%Synthesis of a chelate resin with amido and phosphoric acid and its character in uranium extraction

    Institute of Scientific and Technical Information of China (English)

    仇月双; 张建国; 封宇; 赵潮娅

    2013-01-01

    A chelate resin(D814) with amido and phosphoric acid functional group was synthetized by means of the reactions of stytene-divinyl benzene chloromethylated sphere with ethylenedianmine and orth-phosphorous acid and formaldehyde. This resin can be used to adsorb uranium from leaching solution with high chloride ion in the rang of pH 1. 33-9. 05,and the adsorption rate of uranium was above 95%. D814 resin had a good ability resistant to high chloride ion. The loading capacity for uranium was not apparently effected when chlorid ion concentration in solution was 60 g/L. The results of the adsorption experiment show that when the ratio of saturation volume to breakthrough volume was 1. 82, the uranium saturation capacity of D814 was 40. 5 mg/g dry resin. NaCl+NaHCO3 was used for elu-ting agent,and the eluting rate of uranium was 96. 7%. Adsorption uranium mechanism by D814 was also discussed.%苯乙烯-二乙烯苯氯球与乙二胺、亚磷酸、甲醛反应合成了一种带有氨基膦酸螯合基团的大孔树脂(D814),此树脂适用范围宽,能够从pH为1.33~9.05的高氯根浸出液中有效吸附铀,铀吸附率大于94%.树脂耐氯性能好,当原液中ρ(Cl-)达到60 g/L时,对树脂铀的吸附性能仍无明显影响.动态吸附表明,树脂吸附饱和体积与穿透树脂体积之比为1.82,每g干树脂铀吸附饱和容量为40.5 mg.选用NaCl+ NaHCO3混合淋洗剂,铀的淋洗率达到96.7%.对D814树脂的铀吸附机制进行了初步分析.

  12. Estudo da ação do extrato de Ginkgo biloba e amido hidroxietílico hipertônico na atenuação de alterações decorrentes de isquemia e reperfusão de órgãos esplâncnicos em ratos

    Directory of Open Access Journals (Sweden)

    Macarenco Ricardo Silvestre e Silva

    2001-01-01

    Full Text Available A oclusão e reperfusão das artérias esplâncnicas ocasiona choque circulatório, causado principalmente pelo aumento de permeabilidade vascular e pela agressão celular provocada por radicais livres derivados do oxigênio. Este estudo tem por finalidade verificar a ação do extrato de Ginkgo biloba (Egb-761 e do amido hidroxietílico (AHH na prevenção do choque circulatório produzido pela isquemia e reperfusão de órgãos esplâncnicos. O Egb-761 tem propriedades antioxidantes relatadas na literatura. O AHH, tem sido utilizado como recurso terapêutico do choque hipovolêmico. Ratos anestesiados receberam infusão contínua de Egb-761 ou AHH, sendo submetidos à isquemia (oclusão do tronco celíaco, artéria mesentérica superior e artéria mesentérica inferior por 30 minutos e reperfusão (por 90 minutos dos órgãos esplâncnicos. Foram feitas: análise histopatológica ileal, dosagem de malondialdeído ileal e determinação contínua da pressão arterial média (PAM. A PAM ao final do período de reperfusão foi significativamente mais elevada nos animais tratados com Egb-761 e AHH, que no grupo controle (F=18,29; p0,10 e quanto às alterações histológicas (H=6,003; p>0,10. Em conclusão, houve melhora nas condições hemodinâmicas, com atenuação do choque nos ratos que receberam Egb-761 ou AHH. Novos estudos serão necessários para se avaliar melhor as alterações histológicas e para esclarecer a formação de produtos finais da peroxidação lipídica.

  13. Primary Teacher Education in Malaysia

    Science.gov (United States)

    Ching, Chin Phoi; Yee, Chin Peng

    2012-01-01

    In Malaysia the training of primary school teachers is solely carried out by teacher training institutes which offer the Bachelor of Teaching with Honors (Primary education) program and was first launched in 2007. This program prepares primary school teachers specializing in various subjects or major and is carried out in 27 teacher training…

  14. Primary and secondary stabbing headache.

    Science.gov (United States)

    Robbins, Matthew S; Evans, Randolph W

    2015-04-01

    Eight out of the 33 cases of primary stabbing headache seen in a general neurology clinic (40% have headache as their chief complaint) in the last 3.5 years are presented. The epidemiology, association with other primary headache disorders, secondary associations, testing, and treatment of primary stabbing headache are reviewed.

  15. Primary osteoporosis in children.

    Science.gov (United States)

    Tan, Lay Ong; Lim, Soo Yen; Vasanwala, Rashida Farhad

    2017-09-01

    Osteoporosis in childhood is uncommon, and it may be secondary to a spectrum of diverse conditions. Idiopathic juvenile osteoporosis is a primary osteoporosis of unknown aetiology present in previously well children and is a diagnosis of exclusion. We describe a 10-year-old prepubertal boy who presented with back pain of 1-week duration. His spinal X-ray showed generalised loss of vertebral body heights in keeping with osteoporosis. Endocrine and haematological work-up were normal. He was treated with vitamin D supplement and intravenous pamidronate. This case illustrates the general work-up and causes for paediatric osteoporosis, and the management for idiopathic juvenile osteoporosis. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. Primary conjunctival amyloidosis

    Directory of Open Access Journals (Sweden)

    Chandana Chakraborti

    2014-01-01

    Full Text Available A 19-year-old previously healthy male presented with a 4 year history of painless drooping of right upper eyelid.On eversion of the right upper eyelid, a yellowish pink mass was seen in the tarsal region. Rest of the ocular examination was normal in both the eyes. Initial biopsy showed chronic inflammation. Subsequently, the entire mass was excised and histopathological examination showed the presence of amyloid in the subconjunctival stroma. At 3 months follow-up, similar lesion was detected in the right lower, left upper, and lower lid, which were treated with cryotherapy, with partial resolution. Patient has been followed up for more than 2 years without any complaints. To our knowledge, this is the first case report of an isolated primary conjunctival amyloidosis with involvement of both the upper and lower palpebral conjunctiva of either eye. It was treated successfully by excision and cryotherapy.

  17. Apoptosis in Primary Hyperparathyroidism.

    Science.gov (United States)

    Segiet, Oliwia Anna; Mielańczyk, Łukasz; Piecuch, Adam; Michalski, Marek; Tyczyński, Szczepan; Brzozowa-Zasada, Marlena; Deska, Mariusz; Wojnicz, Romuald

    2017-03-31

    Primary hyperparathyroidism (PHPT) is defined by inappropriate elevation of parathormone, caused by parathyroid hyperplasia, also known as multi-gland disease (MGD), parathyroid adenoma (PA), or parathyroid carcinoma (PC). Although several studies have already been conducted, there is a lack of a definite diagnostic marker, which could unambiguously distinguish MGD from PA or PC. The accurate and prompt diagnosis has the key meaning for effective treatment and follow-up. This review paper presents the role of apoptosis in PHPT. The comparison of the expression of Fas, TRAIL, BCL-2 family members, p53 in MGD, PA, and PC, among others, was described. The expression of described factors varies among proliferative lesions of parathyroid gland; therefore, these could serve as additional markers to assist in the diagnosis.

  18. PRIMARY SCHOOL TEACHER

    CERN Multimedia

    Madeleine Dittus

    2002-01-01

    For the beginning of the school year 2002/2003, the A.P.E.G. has an opening for a primary school teacher in the German national language program. The position requires one afternoon of teaching (13:30 till 16:30) every Tuesday at the Collège in Prévessin. The candidate should be a native speaker of German and have some knowledge of French. If you are interested, please send your CV, a copy of your diploma, and a short letter of motivation, until March 10th, to the following address. Madeleine Dittus - Présidente A.P.E.G. 5, La vie Destraz 01630 St. Genis-Pouilly - France

  19. Primary care guidelines

    DEFF Research Database (Denmark)

    Ijäs, Jarja; Alanen, Seija; Kaila, Minna

    2009-01-01

    -sectional telephone survey. SETTING: All municipal health centres in Finland. SUBJECTS: Health centres where both the head physician and the senior nursing officer responded. MAIN OUTCOME MEASURES: Agreement in views of the senior executives on the adoption of clinical practices as recommended in the Hypertension......OBJECTIVE: To describe the adoption of the national Hypertension Guideline in primary care and to evaluate the consistency of the views of the health centre senior executives on the guideline's impact on clinical practices in the treatment of hypertension in their health centres. DESIGN: A cross...... Guideline. RESULTS: Data were available from 143 health centres in Finland (49%). The views of head physicians and senior nursing officers on the adoption of the Hypertension Guideline were not consistent. Head physicians more often than senior nursing officers (44% vs. 29%, p

  20. [Primary spontaneous pneumomediastinum].

    Science.gov (United States)

    Togashi, K; Hosaka, Y

    2007-12-01

    We report 5 cases of spontaneous pneumomediastinum. They were 4 men and 1 female with a mean age of 17 (14-25). Four patients developed sport-related pneumomediastinum and 1 patient had a karaoke-related condition. Primary spontaneous pneumomediasinum is a rare condition. In addition, there is no previous report describing karaoke-related spontaneous pneumomediastinum. Each of the patients experienced chest pain and/or neck pain before consulting our hospital. Chest roentgenogram and chest computed tomography showed pneumomediastinum without esophageal or tracheal injury. Four patients did not require hospitalization, but 1 patient was necessary to hospitalize for 7 days because of severe chest and neck pain. None of these 5 patients has had any recurrence for more than 1 year. Differentiating this entity from other diseases involving anterior chest pain is important.

  1. Primary hyperparathyroidism in pregnancy.

    Science.gov (United States)

    Kamenický, Peter; Lecoq, Anne-Lise; Chanson, Philippe

    2016-06-01

    Primary hyperparathyroidism (PHPT) is one of the most common endocrine disorders in the general population but is rarely diagnosed during pregnancy. Symptoms of gestational PHPT may be unrecognized, or masked by physiological changes in calcium homeostasis associated with pregnancy. Gestational PHPT may have severe consequences for both mother and fetus. However, nowadays, gestational PHPT is usually diagnosed in earlier stages and milder forms, with low complication rates. Treatment should be individually tailored according to gestational age, the severity of hypercalcemia, and the risk-benefit balance. The conservative approach is preferred in mild forms, whereas surgery, usually performed during the second trimester, is reserved for symptomatic hypercalcemic PHPT. Given the young age of the patients, genetic causes should be considered.

  2. Primary aldosteronism. Clinical management

    Energy Technology Data Exchange (ETDEWEB)

    Grant, C.S.; Carpenter, P.; van Heerden, J.A.; Hamberger, B.

    1984-05-01

    We retrospectively reviewed the clinical features, methods of diagnosis and localization, and results of treatment in 105 patients with primary aldosteronism seen between 1969 and 1981. Coincident with the use of computed tomography (CT), /sup 131/I-6-beta-iodomethyl norcholesterol scans (NP-59), and postural response studies, the study group was temporally divided into pre-1976 and post-1976 groups, and subdivided into groups with aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) due to bilateral adrenal hyperplasia. Our results indicate that aldosterone postural response studies and CT differentiate and localize APA and IHA reliably. Adrenalectomy is a safe and effective treatment for APA, whereas medical treatment alone is preferable for IHA.

  3. Primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    Plavec Goran

    2004-01-01

    Full Text Available In patients with chronic respiratory diseases that last since the early childhood, primary ciliary dyskinesia (PCD needs to be considered. Four patients reviewed in this paper were with typical disease history and clinical picture, as well as clear ciliary axonema damage. Complete examination was performed in all the patients, including bronchoscopy with bronchography, and the examination of the biopsy samples of respiratory airways’ mucous membrane, obtained by transmission electron microscope (TEM. In two of the patients spermatozoa were also examined by TEM. Large anatomic deffects of airways were found in all the patients, but pulmonary function was normal (except in one case, representing one of PCD’s significant characteristics. First two cases fulfilled the criteria for Kartagener’s syndrome, which was initially sufficient for the diagnosis of PCD.

  4. Primary Fallopian Tube Carcinoma

    Directory of Open Access Journals (Sweden)

    Prasad K Shetty

    2011-01-01

    Full Text Available Primary Fallopian Tube Carcinoma (PFTC is rare and accounts for about 0.3% of all gynecologic cancers. Less than 1500 cases have been reported in the literature. It arises in postmenopausal women and typically presents with abdominal pelvic pain, vaginal bleeding and watery discharge. However, a correct diagnosis is rarely achieved preoperative, and in many cases, the diagnosis is made after incidental surgery for unrelated conditions commonly being ovarian carcinoma . Compared with ovarian carcinoma, PFTC more often presents at early stages, but it has a worse prognosis. PFTC is usually managed in the same manner as ovarian cancer. We report a case of Left PFTC that presented as Left ovarian mass, and we briefly review the literature.

  5. Primary thrombocytosis in children

    Science.gov (United States)

    Kucine, Nicole; Chastain, Katherine M.; Mahler, Michelle B.; Bussel, James B.

    2014-01-01

    Myeloproliferative neoplasms are uncommon disorders in children, for which we have limited understanding of the pathogenesis and optimal management. JAK2 and MPL mutations, while common drivers of myeloproliferative neoplasms in adult patients, are not clearly linked to pediatric disease. Management and clinical outcomes in adults have been well delineated with defined recommendations for risk stratification and treatment. This is not the case for pediatric patients, for whom there is neither a standard approach to workup nor any consensus regarding management. This review will discuss thrombocytosis in children, including causes of thrombocytosis in children, the limited knowledge we have regarding pediatric primary thrombocytosis, and our thoughts on potential risk stratification and management, and future questions to be answered by laboratory research and collaborative clinical study. PMID:24688110

  6. Primary mediastinal hemangiopericytoma

    Directory of Open Access Journals (Sweden)

    Efstathiou A

    2006-04-01

    Full Text Available Abstract Background Hemangiopericytoma is a rare mesenchymal neoplasm, accounting for about 1% of vascular tumors The tumor occurs most commonly in the skin, subcutaneous soft tissues, muscles of the extremities, retroperitoneum but rarely in the lung, trachea or mediastinum. Case presentation A rare case of primary mediastinal hemangiopericytoma is presented. A 72-year-old woman was treated by complete surgical resection of the tumor. Details of the clinical and radiographic feature are presented. The patient's postoperative course was uneventful with no evidence of recurrence 9 months after the operation. Conclusion Hemangiopericytoma is an uncommon, potentially malignant tumor originating from pericytes in the small vessels and surgical radical excision is the treatment of choice, although the criteria for determining the area of resection have not been established. International literature has demonstrated that recurrent disease usually occurs within 2 years and therefore a long-term careful follow-up is required.

  7. Primary fallopian tube carcinoma

    Directory of Open Access Journals (Sweden)

    Mladenović-Segedi Ljiljana

    2009-01-01

    Full Text Available Introduction. Primary fallopian tube carcinoma is extremely rare, making 0.3-1.6% of all female genital tract malignancies. Although the etymology of this tumor is unknown, it is suggested to be associated with chronic tubal inflammation, infertility, tuberculous salpingitis and tubal endometriosis. High parity is considered to be protective. Cytogenetic studies show the disease to be associated with over expression of p53, HER2/neu and c-myb. There is also some evidence that BRCA1 and BRCA2 mutations have a role in umorogeneis. Clinical features. The most prevailing symptoms with fallopian tube carcinoma are abdominal pain, abnormal vaginal discharge/bleeding and the most common finding is an adnexal mass. In many patients, fallopian tube carcinoma is asymptomatic. Diagnosis. Due to its rarity, preoperative diagnosis of primary fallopian tube carcinoma is rarely made. It is usually misdiagnosed as ovarian carcinoma, tuboovarian abscess or ectopic pregnancy. Sonographic features of the tumor are non-specific and include the presence of a fluid-filled adnexal structure with a significant solid component, a sausage-shaped mass, a cystic mass with papillary projections within, a cystic mass with cog wheel appearance and an ovoid-shaped structure containing an incomplete separation and a highly vascular solid nodule. More than 80% of patients have elevated pretreatment serum CA-125 levels, which is useful in follow-up after the definite treatment. Treatment. The treatment approach is similar to that of ovarian carcinoma, and includes total abdominal hysterectomy and bilateral salpingo-oophorectomy. Staging is followed with chemotherapy.

  8. Comparison between two methods for estimating the digestibility of starch and other nutrients in high moisture sorghum grain silage in horses Comparação entre dois métodos para estimativa da digestibilidade do amido e de outros nutrientes em silagem de grãos úmidos de sorgo em equinos

    Directory of Open Access Journals (Sweden)

    Augusta Martins Romaniello Gollcher

    2010-06-01

    coleta total de fezes na estimativa da digestibilidade aparente do amido e de outros nutrientes em silagens de grãos úmidos de sorgo em equinos. Foram utilizados quatro cavalos adultos sem raça definida, com 7 anos de idade e peso corporal médio de 330 kg. No primeiro ensaio, avaliou-se a digestibilidade dos nutrientes da silagem de grãos úmidos de sorgo com baixo teor de tanino utilizando a coleta total de fezes e a técnica do saco de náilon móvel com amostras da silagem moídas em três granulometrias. No segundo ensaio, foram utilizados os dois métodos na estimativa da digestibilidade dos nutrientes da silagem de grãos úmidos de sorgo alto tanino. O delineamento experimental foi o de blocos casualizados, considerando cada animal um bloco. Também foi avaliado em laboratório o desaparecimento, nos sacos de náilon, dos nutrientes das amostras das silagens de grãos de sorgo úmidos moídas em três granulometrias (1, 8 e 13 mm. A ingestão diária de matéria seca foi de 2,0% do peso corporal, e as dietas-teste foram compostas de 30% de silagem de grãos úmidos de sorgo e 70% de feno de coast-cross. Os coeficientes de digestibilidade da matéria seca, energia e proteína de ambas as silagens foram semelhantes entre as metodologias de coleta total de fezes e a técnica de sacos de náilon móveis quando utilizadas amostras de alimento de 8 mm. O coeficiente de digestibilidade do amido foi similar entre os métodos quando as amostras de sorgo foram moídas a 1 mm na técnica de sacos de náilon móveis. A redução da granulometria aumentou as perdas dos nutrientes dos sacos de náilon após lavagem em água. A técnica dos sacos de náilon móveis permite estimar o coeficiente de digestibilidade dos nutrientes, entretanto devem ser realizados mais estudos para avaliação da granulometria das amostras.

  9. Primary total elbow arthroplasty

    Directory of Open Access Journals (Sweden)

    Suresh Kumar

    2013-01-01

    Full Text Available Background: Primary total elbow arthroplasty (TEA is a challenging procedure for orthopedic surgeons. It is not performed as frequently as compared to hip or knee arthroplasty. The elbow is a nonweight-bearing joint; however, static loading can create forces up to three times the body weight and dynamic loading up to six times. For elderly patients with deformity and ankylosis of the elbow due to posttraumatic arthritis or rheumatoid arthritis or comminuted fracture distal humerus, arthroplasty is one of the option. The aim of this study is to analyze the role of primary total elbow arthroplasty in cases of crippling deformity of elbow. Materials and Methods: We analyzed 11 cases of TEA, between December 2002 and September 2012. There were 8 females and 3 males. The average age was 40 years (range 30-69 years. The indications for TEA were rheumatoid arthritis, comminuted fracture distal humerus with intraarticular extension, and posttraumatic bony ankylosis of elbow joint. The Baksi sloppy (semi constrained hinge elbow prosthesis was used. Clinico-radiological followup was done at 1 month, 3 months, 6 months, 1 year, and then yearly basis. Results: In the present study, average supination was 70° (range 60-80° and average pronation was 70° (range 60-80°. Average flexion was 135° (range 130-135°. However, in 5 cases, there was loss of 15 to 35° (average 25° of extension (45° out of 11 cases. The mean Mayo elbow performance score was 95.4 points (range 70-100. Arm length discrepancy was only in four patients which was 36% out of 11 cases. Clinico-radiologically all the elbows were stable except in one case and no immediate postoperative complication was noted. Radiolucency or loosening of ulnar stem was seen in 2 cases (18% out of 11 cases, in 1 case it was noted after 5 years and in another after 10 years. In second case, revision arthroplasty was done, in which only ulnar hinge section, hinge screw and lock screw with hexagonal head

  10. Liquid cathode primary batteries

    Science.gov (United States)

    Schlaikjer, Carl R.

    1985-03-01

    Lithium/liquid cathode/carbon primary batteries offer from 3 to 6 times the volumetric energy density of zinc/alkaline manganese cells, improved stability during elevated temperature storage, satisfactory operation at temperatures from -40 to +150 °C, and efficient discharge at moderate rates. he lithium/sulfur dioxide cell is the most efficient system at temperatures below 0 °C. Although chemical reactions leading to electrolyte degradation and lithium corrosion are known, the rates of these reactions are slow. While the normal temperature cell reaction produces lithium dithionite, discharge at 60 °C leads to a reduction in capacity due to side reactions involving sulfur dioxide and discharge intermediates. Lithium/thionyl chloride and lithium/sulfuryl chloride cells have the highest practical gravimetric and volumetric energy densities when compared with aqueous and most other nonaqueous systems. For thionyl chloride, discharge proceeds through a series of intermediates to sulfur, sulfur dioxide and lithium chloride. Catalysis, leading to improved rate capability and capacity, has been achieved. The causes of rapid reactions leading to thermal runaway are thought to be chemical in nature. Lithium/sulfuryl chloride cells, which produce sulfur dioxide and lithium chloride on discharge, experience more extensive anode corrosion. An inorganic cosolvent and suitable salt are capable of alleviating this corrosion. Calcium/oxyhalide cells have been studied because of their promise of increased safety without substantial sacrifice of energy density relative to lithium cells. Anode corrosion, particularly during discharge, has delayed practical development.

  11. Management of primary hypothyroidism.

    Science.gov (United States)

    Nordyke, R A; Gilbert, F I

    1990-07-01

    Primary hypothyroidism is a common condition requiring lifelong treatment and monitoring. The type and amount of thyroid hormone replacement, selection of laboratory tests, and timing of office visits are all important for optimizing patient well-being and reducing the costs of medical care. The aim of treatment is to bring the patient to the euthyroid state. Currently this is defined as a normal serum concentration of TSH by recently developed sensitive and specific immunometric assays, and is accomplished by titrating the dose of levothyroxine and changing it not more often than at 4- to 6-week intervals. As an indicator of euthyroidism, the sensitive TSH assay has advantages over tests of serum T4, FT4I, T3, FT4, and TSH by RIA because it is independent of TBG changes that result from pregnancy, birth-control pills, and estrogen replacement, is not spuriously elevated by the levothyroxine treatment itself, and is the only test that detects both subclinical hypothyroidism and subclinical hyperthyroidism. Additional serum tests are not usually necessary but have advantages under special circumstances. Once the optimal replacement dose is determined, monitoring can be done yearly or even bi-yearly, depending on the adequacy of patient education and patient compliance.

  12. Primary sclerosing cholangitis

    Directory of Open Access Journals (Sweden)

    Marina G Silveira

    2008-01-01

    Full Text Available Primary sclerosing cholangitis (PSC is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the bile ducts, resulting in end-stage liver disease and reduced life expectancy. PSC primarily affects young and middle-aged men, often in association with underlying inflammatory bowel disease. The etiology of PSC includes immune-mediated components and elements of undefined nature. A cholestatic picture of liver biochemistries with elevations in serum alkaline phosphatase, nonspecific autoantibodies such as perinuclear antineutrophilic antibody, antinuclear antibodies and smooth muscle antibodies, and diffuse multifocal biliary strictures, resulting in a ‘beaded’ appearance on radiographic studies, are the hallmarks of the disease. No effective medical therapy is currently available, although clinical studies are in progress. Ursodeoxycholic acid at high doses (28 mg/kg/day to 30 mg/kg/day is the most promising agent but is unproven so far. Liver transplantation is currently the only life-extending therapy for patients with end-stage disease, although recurrent disease can be observed in the transplanted liver. The multiple complications of PSC include pruritus, fatigue, vitamin deficiencies, metabolic bone disease, peristomal varices, bacterial cholangitis, dominant biliary strictures, gallbladder stones and polyps, and malignancy, particularly cholangiocarcinoma, which is the most lethal complication of PSC.

  13. Primary sclerosing cholangitis

    Directory of Open Access Journals (Sweden)

    Chapman Roger

    2006-10-01

    Full Text Available Abstract Primary sclerosing cholangitis (PSC is a chronic cholestatic liver disease of unknown aetiology characterised by inflammation and fibrosis of the biliary tree. The mean age at diagnosis is 40 years and men are affected twice as often as women. There is a reported annual incidence of PSC of 0.9–1.31/100,000 and point prevalence of 8.5–13.6/100,000. The onset of PSC is usually insidious and many patients are asymptomatic at diagnosis or have mild symptoms only such as fatigue, abdominal discomfort and pruritus In late stages, splenomegaly and jaundice may be a feature. In most, the disease progresses to cirrhosis and liver failure. Cholangiocarcinoma develops in 8–30% of patients. PSC is thought to be immune mediated and is often associated with inflammatory bowel disease, especially ulcerative colitis. The disease is diagnosed on typical cholangiographic and histological findings and after exclusion of secondary sclerosing cholangitis. Median survival has been estimated to be 12 years from diagnosis in symptomatic patients. Patients who are asymptomatic at diagnosis, the majority of whom will develop progressive disease, have a survival rate greater than 70% at 16 years after diagnosis. Liver transplantation remains the only effective therapeutic option for patients with end-stage liver disease from PSC, although high dose ursodeoxycholic acid may have a beneficial effect.

  14. Primary multidrug resistant tuberculosis

    Directory of Open Access Journals (Sweden)

    Sarkar Supriya

    2007-01-01

    Full Text Available A 37-year old man presented at our institution with back pain, low-grade fever and weight-loss. X-ray of chest (postero-anterior view showed multiple opacities with erosion of right 2nd and left 6th ribs. CT-scan of thorax and CT-guided FNAC con-firmed the diagnosis of tuberculosis of ribs. Even after 5-months of treatment with four first line drugs, the patient developed a cold abscess at the back. Mycobacterial culture and drug sensitivity of material aspirated by Radiometric method from the cold abscess showed growth of Mycobacterium tuberculosis, and those bacilli were resistant to both isoniazide and rifampicin. The patient did not have anti-tubercu-lar medication in the past, and that established the diagnosis of primary multidrug resistant tuberculosis of ribs. Patient was treated successfully with 2nd line drugs at the cost of moderate degree of hearing loss. After one and half years of treatment X-ray of chest (PA view showed complete healing of rib erosions with new bone formation.

  15. Liquid cathode primary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schlaikjer, C.R.

    1985-01-15

    Lithium/liquid cathode/carbon primary batteries offer from 3 to 6 times the volumetric energy density of zinc/alkaline manganese cells, improved stability during elevated temperature storage, satisfactory operation at temperatures from -40 to +150/sup 0/C, and efficient discharge at moderate rates. The lithium/sulfur dioxide cell is the most efficient system at temperatures below 0/sup 0/C. Although chemical reactions leading to electrolyte degradation and lithium corrosion are known, the rates of these reactions are slow. While the normal temperature cell reaction produces lithium dithionite, discharge at 60/sup 0/C leads to a reduction in capacity due to side reactions involving sulfur dioxide and discharge intermediates. Lithium/thionyl chloride and lithium/sulfuryl chloride cells have the highest practical gravimetric and volumetric energy densities when compared with aqueous and most other nonaqueous systems. For thionyl chloride, discharge proceeds through a series of intermediates to sulfur, sulfur dioxide and lithium chloride. Catalysis, leading to improved rate capability and capacity, has been achieved. The causes of rapid reactions leading to thermal runaway are thought to be chemical in nature. Lithium/sulfuryl chloride cells, which produce sulfur dioxide and lithium chloride on discharge, experience more extensive anode corrosion. An inorganic cosolvent and suitable salt are capable of alleviating this corrosion. Calcium/oxyhalide cells have been studied because of their promise of increased safety without substantial sacrifice of energy density relative to lithium cells. Anode corrosion, particularly during discharge, has delayed practical development.

  16. Primary gastrointestinal lymphoma

    Institute of Scientific and Technical Information of China (English)

    Prasanna Ghimire; Guang-Yao Wu; Ling Zhu

    2011-01-01

    Gastrointestinal tract is the most common extranodal site involved by lymphoma with the majority being non-Hodgkin type. Although lymphoma can involve any part of the gastrointestinal tract, the most frequent sites in order of its occurrence are the stomach followed by small intestine and ileocecal region. Gastrointestinal tract lymphoma is usually secondary to the widespread nodal diseases and primary gastrointestinal tract lymphoma is relatively rare. Gastrointestinal lymphomas are usually not clinically specific and indistinguishable from other benign and malignant conditions. Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma in essentially all sites of the gastrointestinal tract, although recently the frequency of other forms has also increased in certain regions of the world. Although some radiological features such as bulky lymph nodes and maintenance of fat plane are more suggestive of lymphoma, they are not specific,thus mandating histopathological analysis for its definitive diagnosis. There has been a tremendous leap in the diagnosis, staging and management of gastrointestinal lymphoma in the last two decades attributed to a better insight into its etiology and molecular aspect as well as the knowledge about its critical signaling pathways.

  17. Primary hyperoxaluria in infants

    Directory of Open Access Journals (Sweden)

    Manel Jellouli

    2016-01-01

    Full Text Available The infantile form of primary hyperoxaluria type-1 (PH-1 is characterized by a rapid progression to the end-stage renal disease (ESRD due to both increased oxalate load and reduced glomerular filtration rate. In the literature, data on this form are limited. The purpose of this study is to analyze retrospectively the clinical, biological, and radiological features of children who were diagnosed with PH-1 during the 1styear of life. We reviewed the records of all children with PH-1 diagnosed and followed-up at our department between January 1995 and December 2013. Among them, only infants younger than 12 months of age were retrospectively enrolled in the study. Fourteen infants with the median age of two months were enrolled in the study. At diagnosis, 11 patients had ESRD. All patients had nephrocalcinosis and two of them had calculi. The diagnosis was established in nine patients on the basis of the positive family history of PH-1, bilateral nephrocalcinosis, and quantitative crystalluria. In four patients, the diagnosis was made with molecular analysis of DNA. Kidney biopsy contributed to the diagnosis in one patient. During follow-up, two patients were pyridoxine sensitive and preserved renal function. Seven among 11 patients who had ESRD died, four patients are currently undergoing peritoneal dialysis. Children with infantile PH and ESRD are at high risk of early death. Peritoneal dialysis is not a treatment of choice. Combined liver-kidney transplantation is mandatory.

  18. Primary pulmonary hypertension.

    Science.gov (United States)

    Rashid, A; Lehrman, S; Romano, P; Frishman, W; Dobkin, J; Reichel, J

    2000-01-01

    Primary pulmonary hypertension (PPH) is a condition characterized by sustained elevation of pulmonary artery pressure (PAP) without demonstrable cause. The most common symptom at presentation is dyspnea. Other complaints include fatigue, chest pain, syncope, leg edema, and palpitations. Right heart catheterization is diagnostic, showing a mean PAP >25 mmHg at rest and >30 mmHg during exercise, with a normal pulmonary capillary wedge pressure. In the National Institutes of Health-PPH registry, the median survival period was 2.8 years. Treatment is aimed at lowering PAP, increasing cardiac output, and decreasing in situ thrombosis. Vasodilators have been used with some success in the treatment of PPH. They include prostacyclin, calcium-channel blockers, nitric oxide and adenosine. Anticoagulation has also been advised for the prevention of deep vein thrombosis, pulmonary embolism, and in situ thromboses of the lungs. New drug treatments under investigation include L-arginine, plasma endothelin-I, and bosentan. Use of oxygen, digoxin, and diuretics for symptomatic relief have also been recommended. Patients with severe PPH refractory to medical management should be considered for surgery.

  19. The primary hyperoxalurias.

    Science.gov (United States)

    Bobrowski, Amy E; Langman, Craig B

    2008-03-01

    The primary hyperoxalurias (PHs) are rare autosomal-recessive inborn errors of metabolism. In the most severe form (type 1), recurrent kidney stones and progressive nephrocalcinosis lead to the loss of kidney function, accompanied by systemic oxalosis, and often requires dialysis and/or transplantation. The variety of genetic mutations leading to PH increasingly are being defined, resulting in the ability to diagnose most patients accurately via minimally invasive means. During and after definitive diagnosis, supportive therapies with pyridoxine supplementation, urinary crystallization inhibitors, and hydration should be used, but have varying success. Emerging information about the renal tubular and intestinal transport of oxalate is leading to increasing evidence to support the use of oxalate-degrading bacteria (probiotics) and enzymes in the treatment of PH. Organ transplantation historically has offered the only potential cure for PH, and may include kidney-alone, combined liver-kidney, or pre-emptive liver-alone transplantation. Exciting new approaches in the treatment of type 1 PH, however, are under investigation. These include the restoration of defective enzymatic activity through the use of chemical chaperones, hepatocyte cell transplantation, or enzyme replacement by recombinant gene therapy. These novel approaches illustrate the goal for the ideal treatment of PH: correcting the genetic defect without exposing patients to the life-long risks associated with organ transplantation.

  20. Parapharyngeal space primary tumours.

    Science.gov (United States)

    Grilli, Gianluigi; Suarez, Vanessa; Muñoz, María Gabriela; Costales, María; Llorente, José Luis

    The aim of this study is to present our experience with the diagnostic and therapeutic approaches for parapharyngeal space tumours. This study is a retrospective review of 90 patients diagnosed with tumours of the parapharyngeal space and treated surgically between 1984 and 2015. Patients whose tumours were not primary but invaded the parapharyngeal space expanding from another region, tumours originating in the deep lobe of the parotid gland and head and neck metastasis were excluded from this study. 74% percent of the parapharyngeal space neoplasms were benign and 26% were malignant. Pleomorphic adenoma was the most common neoplasm (27%), followed by paragangliomas (25%), miscellaneous malignant tumours (16%), neurogenic tumours (12%), miscellaneous benign tumours (10