958 resultados para 4,5-dihydroxy-1,3-benzène disulphonate


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RESUMO: Objectivo: Face à exiguidade de estudos em Portugal nesta temática, o objectivo do estudo foi a análise entre a aptidão cardiorrespiratória (ACR), e a prevalência da pré-obesidade e obesidade em crianças do 4º ano do 1º ciclo. Método: Foi efectuada uma revisão sistemática da literatura (RSL), evocando-se estudos tranversais e de RCT, cruzando-se com resultados do estudo observacional, do Agrupamento de Escolas Professor Armando Lucena, do concelho de Mafra, distrito de Lisboa. Do estudo de RSL, e estudo observacional, fez-se a análise da verificação da associação inversa, entre a “aptidão cardiorespiratória, a pré-obesidade e obesidade”. O estudo observacional, foi transversal, incidindo sobre 143 crianças, (73 raparigas) dos 9-12 anos de idade do concelho de Mafra. Foram utilizados os pontos de corte da International Obesity Task Force (IOTF), para definir a pré-obesidade e obesidade. Registou-se o IMC e a % Massa Gorda por bioimpedância. A avaliação da ACR foi efectuada através do teste Vaivém 20 metros Fitnessgram, utilizando-se equação de Fernhall et al., (1998). Os alunos foram avaliados por questionário sobre actividade física (AF) extra-curricular (QAD, Telama et al., 1997); os pais sobre os níveis AF (IPAQ, Bauman et al., 2009) e estatuto sócio-económico (ESE). Resultados: Os resultados do estudo observacional, corroboram os de outros estudos RSL. Não houve diferenças entre géneros na prevalência de pré-obesidade e obesidade: rapazes (20.55% e 8.21%) e raparigas (34.28% e 5.71%) (p<0.176). As crianças com maior ACR têm menor IMC (p<0.01) e MG (p<0.001) e a idade não esteve associada à ACR. Os pré-obesos são na sua maioria insuficientemente activos, e os normoponderais são insuficientemente activos (p=0.033). Não houve associação entre o ESE e AF dos pais e o IMC, ACR ou QAD dos alunos. Com base nos resultados encontrados na revisão, procurou-se situar diferentes abordagens teóricas sobre a actividade física, dando ênfase principal à importância “ da promoção (acesso) da actividade física através da educação física orientada pedagogicamente em todos os ciclos de ensino. Conclusão: As crianças que tiveram maior ACR registaram menor IMC e MG, independente da idade e do sexo. Verificou-se ainda que as variáveis de ESE e AF dos pais, não está associada aos resultados da ACR, IMC e MG das crianças. ABSTRACT: Objective: Given the paucity of studies in Portugal on this theme, the goal of the study was to analyse the of cardiorespiratory fitness (CRF), and the prevalence of overweight and obesity in children attending the fourth year of primary school. Method: A systematic literature review was conducted, in which cross-cutting studies and RCT were covered and, intersected with observational results obtained, from the group of Schools Professor Armando Lucena, located in, the municipality of Mafra, Lisbon district. From the systematic review of literature (SRL), plus the observational study, the verification analysis of the inverse association between 'cardiorespiratory fitness, pre-obesity and obesity' was performed.The observational study was cross-sectional, focusing on 143 children (73 girls) of 9-12 years old. To define overweight and obesity the IOTF cutoffs were used. BMI and percentage of fat mass were recorded by means of bioelectrical impedance. The assessment was made through the CRF test shuttle Fitnessgram 20 meters, using the equation proposed by Fernhall et al., (1998). Students were assessed by questionnaire on physical activity (PA), extra-curricular PA (PAF Telama et al., 1997); parents were questioned regarding their PA levels (IPAQ, Bauman et al., 2009) and socio-economic status (SES). Results: The results of the observational study, corroborate, other SRL studies. There were no gender differences in the prevalence of overweight and obesity: men (20. 55% and 8.21%) and girls (34.28% and 5.71%) (p <0.176). Children with higher BMI have a lower CRF (p <0.01) and MG (p <0.001). Age was not observed to be associated with CRF. The pre-obese are mostly insufficiently active, and the normalweight are insufficiently active (p = 0.033). There was no association between the PA, the ESS, the parents, and the BMI, the CRF or the PAF of the students. Based on the results found in the review, different theoretical approaches regarding physical activity were. Emphasis was given to the importance of promoting the access to physical activity through pedagogically oriented physical education in all cycles of education. Conclusion: Children who had higher ACR showed lower FAT and BMI, regardless of age and sex. Furthermore, it was found that parents’ SES and PA variables are, not associated to children’s CRF, BMI and FAT.

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IMAC can be used to selectively enrich phosphopeptides from complex peptide mixtures, but co-retention of acidic peptides together with the failure to retain some phosphopeptides restricts the general utility of the method. In this study Fe(III)-IMAC was qualitatively and quantitatively assessed using a panel of phosphopeptides, both synthetic and derived from proteolysis of known phosphoproteins, to identify the causes of success and failure in the application of this technique. Here we demonstrate that, as expected, peptides with a more acidic amino acid content are generally more efficiently purified and detected by MALDI-MS after Fe(III)-IMAC than those with a more basic content. Modulating the loading buffer used for Fe(III)-IMAC significantly affects phosphopeptide binding and suggests that conformational factors that lead to steric hindrance and reduced accessibility to the phosphate are important. The use of 1,1,1,3,3,3-hexafluoroisopropanol is shown here to significantly improve Fe(III)-IMAC enrichment and subsequent detection of phosphopeptides by MALDI-MS.

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IMAC can be used to selectively enrich phosphopeptides from complex peptide mixtures, but co-retention of acidic peptides together with the failure to retain some phosphopeptides restricts the general utility of the method. In this study Fe(III)-IMAC was qualitatively and quantitatively assessed using a panel of phosphopeptides, both synthetic and derived from proteolysis of known phosphoproteins, to identify the causes of success and failure in the application of this technique. Here we demonstrate that, as expected, peptides with a more acidic amino acid content are generally more efficiently purified and detected by MALDI-MS after Fe(III)-IMAC than those with a more basic content. Modulating the loading buffer used for Fe(III)-IMAC significantly affects phosphopeptide binding and suggests that conformational factors that lead to steric hindrance and reduced accessibility to the phosphate are important. The use of 1,1,1,3,3,3-hexa-fluoroisopropanol is shown here to significantly improve Fe(III)-IMAC enrichment and subsequent detection of phosphopeptides by MALDI-MS.

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The chiral stabilised azomethine ylide formed from condensation of the dimethyl acetal of acetone with (5S)-5-phenylmorpholinone undergoes stereoselective exo-cycloaddition reactions with a range of doubly and singly activated dipolarophiles when generated in the presence of excess (MgBr2OEt2)-O-.. The cycloadducts can be degraded to yield enantiomerically pure proline derivatives.

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A highly efficient process for oxidative degradation of 1,3-dialkylimidazolium ionic liquids in hydrogen peroxide/acetic acid aqueous medium assisted by ultrasonic chemical irradiation is, for the first time, described. It is shown that more than 93% of the 1,3-dialkylimidazolium cation with the corresponding Cl-, Br-, BF4- and PF6- counter-anions at a concentration of 2.5 mM can be degraded at 50 degrees C within 12 h while at 72 h the conversions approach 99%. A tentative mechanism for the degradation of these ILs is for the first time proposed through a detailed kinetic analysis of several characteristic transients and/or immediate products, which are identified during the ILs degradation using GC-MS. The results clearly indicate that three hydrogen atoms in the imidazolium ring are the first sites preferably oxidized, followed by cleavage of the alkyl groups attached to the N atoms from the ring. The nature of the alkyl chain length on the imidazolium ring and the type of counter anion do not seem to affect the degradation process. Further, selective fragmentations of C-N bonds of the imidazolium or derived ring lead to ring opening, forming degraded intermediates. It is also shown that acetoxyacetic acid and biurea are the final kinetically stable degraded products from the ILs under the degradation conditions.

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Two polymeric azido bridged complexes [Ni2L2(N-3)(3)](n)(ClO4). (1) and [Cu(bpdS)(2)(N-3)],(ClO4),(H2O)(2.5n) (2) [L = Schiff base, obtained from the condensation of pyridine-2-aldehyde with N,N,2,2-tetramethyl-1,3-propanediamine; bpds = 4,4'-bipyridyl disulfide] have been synthesized and their crystal structures have been determined. Complex 1, C26H42ClN15Ni2O4, crystallizes in a triclinic system, space group P1 with a 8.089(13), b = 9.392(14), c = 12.267(18) angstrom, a = 107.28(l), b 95.95(1), gamma = 96.92(1)degrees and Z = 2; complex 2, C20H21ClCuN7O6.5S4, crystallizes in an orthorhombic system, space group Pnna with a = 10.839(14), b = 13.208(17), c = 19.75(2) angstrom and Z = 4. The crystal structure of I consists of 1D polymers of nickel(L) units, alternatively connected by single and double bridging mu-(1,3-N-3) ligand with isolated perchlorate anions. Variable temperature magnetic susceptibility data of the complex have been measured and the fitting,of magnetic data was carried out applying the Borris-Almenar formula for such types of alternating one-dimensional S = 1 systems, based on the Hamiltonian H = -J Sigma(S2iS2i-1 + aS(2i)S(2i+1)). The best-fit parameters obtained are J = -106.7 +/- 2 cm(-1); a = 0.82 +/- 0.02; g = 2.21 +/- 0.02. Complex 2 is a 2D network of 4,4 topology with the nodes occupied by the Cu-II ions, and the edges formed by single azide and double bpds connectors. The perchlorate anions are located between pairs of bpds. The magnetic data have been fitted considering the complex as a pseudo-one-dimensional system, with all copper((II)) atoms linked by [mu(1,3-azido) bridging ligands at axial positions (long Cu...N-3 distances) since the coupling through long bpds is almost nil. The best-fit parameters obtained with this model are J = -1.21 +/- 0.2 cm(-1), g 2.14 +/- 0.02. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).

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In the crystal structure of the title compound [systematic name: 5H-dibenzo[a,d]cycloheptatriene-5-carboxamide-1,4dioxane(2/1)], 2C(16)H(13)NO center dot C4H8O2, the cytenamide molecules form a hydrogen-bonded R-2(2)(8) dimer. The solvent molecule is located between two adjacent cytenamide dimers and forms N-H center dot center dot center dot O hydrogen bonds with one cytenamide molecule from each dimer.

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The IR and ligand field spectra and the structure of the mixed-ligand compound [N,N-dimethyl-N′-ethyl-1,2-diaminoethane(1-phenyl-1,3-butanedionato)(perchlorato)copper(II)]), [Cu(dmeen)bzac(OClO3)], are reported. The structure was determined by single crystal X-ray diffraction analysis (triclinic, space group ). The structure is square pyramidal with the apical position occupied by one oxygen of the tetrahedral perchlorato group (distance from copper 2.452(5) Å). The plane of the phenyl ring is tilted forming an angle of 16.72(14)° with the plane of the β-dionato moiety. The nitrogenous base adopts the gauche conformation with torsional angle of 108.72(14)°. The ethyl group is cis oriented relative to the phenyl group, occupying the equatorial position with the vector of the carbon-nitrogen bond forming an angle of 143.9(3)° with the CuNN plane. The interactions of the adjacent axial hydrogen with an oxygen of the perchlorato group result in hydrogen bond formation. The IR spectra reveal that in the solid state the Br− or Cl− displace easily the ClO4− group. The shifts in the ligand field spectra indicate that polar solvents participate in donor-acceptor interactions with the metal centre along an axis perpendicular to the CuN2O2 plane.

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Copper(II) acetate reacts with benzene-1,2-dioxyacetic acid (bdoaH2) in aqueous media to give [Cu(bdoa)(H2O)2] (1). Complex 1 reacts with the N-donor ligands pyridine (py), ammonia and 1,10-phenanthroline (phen) to give [Cu(bdoa)(NH3)2]·H2O (2), [Cu(bdoa)(py)2]·H2O (3) and [Cu2(bdoa)(phen)4]bdoa·13H2O (4), respectively. The X-ray crystal structure of the dicopper(II,II) complex 4 shows each copper atom at the centre of a distorted trigonal bipyramid comprising four nitrogen atoms from two chelating phen ligands and a single oxygen atom from one of the carboxylate moieties of the bridging bdoa2− ligand. The cyclic voltammogram of 4 shows a single reversible wave for the Cu2+/Cu+ couple at E = + 115 mV (vs Ag/AgCl). Spectroscopic and magnetic data for the complexes are given.

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Two new Mn(III) complexes of formulas [MnL1(N-3)(OMe)](2) (1) and [MnL2(N-3)(2)](n) (2) have been synthesized by using two tridentate NNO-donor Schiff base ligands HL1{(2-[(3-methylaminoethylimino)-methyl]-phenol)} and HL2 {(2-[1-(2-dimethylaminoethylimino)methyl]-phenol)}, respectively. Substitution of the H atom on the secondary amine group of the N-methyldiamine fragment of the Schiff base by a methyl group leads to a drastic structural change from a methoxido-bridged dimer (1) to a single mu(1,3)-azido-bridged 1D helical polymer (2). Both complexes were characterized by single-crystal X-ray structural analyses and variable-temperature magnetic susceptibility measurements. The magnetic properties of compound I show the presence of weak ferromagnetic exchange interactions mediated by double methoiddo bridges (J = 0.95 cm(-1)). Compound 2 shows the existence of a weak antiferromangetic coupling along the chain (J = -8.5 cm(-1)) through the single mu(1,3)-N-3 bridge with a spin canting that leads to a long-range antiferromagnetic order at T-c approximate to 9.3 K and a canting leading to a weak ferromagnetic long-range order at T-c approximate to 8.5 K. It also exibits metamagnetic behavior at low temperatures with a critical field of ca.1.2 T due to the weak antiferromagnetic interchain interactions that appear in the canted ordered phase.

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Rapeseed meal (RSM) hydrolysate was evaluated as substitute for commercial nutrient supplements in 1,3-propanediol (PDO) fermentation using the strain Clostridium butyricum VPI 1718. RSM was enzymatically converted into a generic fermentation feedstock, enriched in amino acids, peptides and various micro-nutrients, using crude enzyme consortia produced via solid state fermentation by a fungal strain of Aspergillus oryzae. Initial free amino nitrogen concentration influenced PDO production in batch cultures. RSM hydrolysates were compared with commercial nutrient supplements regarding PDO production in fed-batch cultures carried out in a bench-scale bioreactor. The utilization of RSM hydrolysates in repeated batch cultivation resulted in a PDO concentration of 65.5 g/L with an overall productivity of 1.15 g/L/h that was almost 2 times higher than the productivity achieved when yeast extract was used as nutrient supplement.

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1,3-beta-Glucan depolymerizing enzymes have considerable biotechnological applications including biofuel production, feedstock-chemicals and pharmaceuticals. Here we describe a comprehensive functional characterization and low-resolution structure of a hyperthermophilic laminarinase from Thermotoga petrophila (TpLam). We determine TpLam enzymatic mode of operation, which specifically cleaves internal beta-1,3-glucosidic bonds. The enzyme most frequently attacks the bond between the 3rd and 4th residue from the non-reducing end, producing glucose, laminaribiose and laminaritriose as major products. Far-UV circular dichroism demonstrates that TpLam is formed mainly by beta structural elements, and the secondary structure is maintained after incubation at 90 degrees C. The structure resolved by small angle X-ray scattering, reveals a multi-domain structural architecture of a V-shape envelope with a catalytic domain flanked by two carbohydrate-binding modules. Crown Copyright (C) 2011 Published by Elsevier Inc. All rights reserved.

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The major beta-1,3-glucanase from Tenebrio molitor (TLam) was purified to homogeneity (yield, 6%; enrichment, 113 fold; specific activity, 4.4 U/mg). TLam has a molecular weight of 50 kDa and a pH optimum of 6. It is an encloglucanase that hydrolyzes beta-1,3-glucans as laminarin and yeast beta-1,3-1,6-glucan, but is inactive toward other polysaccharides (as unbranched beta-1,3-glucans or mixed beta-1,3-1,4-glucan from cereals) or disaccharides. The enzyme is not inhibited by high substrate concentrations and has low processivity (0.6). TLam has two ionizable groups involved in catalysis, and His, Tyr and Arg residues plus a divalent ion at the active site. A Cys residue important for TLam activity is exposed after laminarin binding. The cDNA coding for this enzyme was cloned and sequenced. It belongs to glycoside hydrolase family 16, and is related to other insect glucanases and glucan-binding proteins. Sequence analysis and homology modeling allowed the identification of some residues (E174, E179, H204, Y304, R127 and R181) at the active site of the enzyme, which may be important for TLam activity. TLam efficiently lyses fungal cells, suggesting a role in making available walls and cell contents to digestion and in protecting the midgut from pathogen infections. (C) 2009 Elsevier Ltd. All rights reserved.