41 resultados para CENTER-DOT-PT
Resumo:
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT center dot There is increasing concern about the use of those medicines in children which have not been fully studied and licensed for childhood use. Such use is not uncommon, due in large part to a lack of availability of fully licensed products and formulations that are suitable for children. center dot There is little published information on the views of the public on this important area of paediatric care. WHAT THIS STUDY ADDS center dot A survey of 1000 members of the public in Northern Ireland indicated that such use of medicines in children is not well known. center dot However, when informed about this practice, the majority believed that it would compromise safety and increase the likelihood of adverse effects. They also believed that parents/guardians should be told if their child was prescribed a medicine that had not been fully tested in children. center dot Participants in the survey indicated that they would be reluctant to involve their child in a clinical trial to help with the licensing process unless the child was suffering from a life-threatening illness. To explore awareness and views of the general public on unlicensed use of medicines in children and on the participation of children in clinical trials. Members of the public completed a questionnaire survey administered by face-to-face interview in public areas in N. Ireland. The main outcome measures were the views on unlicensed use of medicines in children and on clinical trials in children. One thousand participants (59.2% female) took part; 610 were parents. Most participants (86%) had no previous knowledge about unlicensed use of medicines in children. Being a parent did not influence this nor did being a parent of a child who suffered from a health problem (P > 0.05). Most participants (92%) felt that parents should be told about unlicensed use of medicines, with the doctor most frequently selected as the person who should inform parents. At the outset, only 1.8% of participants felt that the use of medicines in children was unsafe. However, having been informed about unlicensed use of medicines, this proportion increased dramatically (62.4%; P <0.001). Views on whether participants would enter a child of their own into a clinical trial varied according to the health status of the child (P <0.05) i.e. a child in good health (3.9%) vs a child with a life-threatening condition (41.9%). There is limited public knowledge of unlicensed use of medicines in children and a general reluctance to involve children in clinical trials unless the child to be involved has a life-threatening condition.
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A study has been carried Out to determine the relative activity Of triclabendazole (TCBZ) and its sulphoxide (TCBZ(center dot)SO) and sulphone (TCBZ(center dot)SO(2)) metabolites against the adult stage of the liver fluke, Fasciola hepatica. Flukes were incubated for 24 h in vitro in 15 mu g/ml of each of the compounds and prepared for scanning and transmission electron microscopy.
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The task-specific ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N], was used to dissolve metal oxides and hydroxides. The crystal structures of the resulting metal betaine bistriflimide complexes exhibit a rich structural variety. A trimeric structure was found for the cobalt(II) compound, [Co-3(bet)(8)(Hbet)(2)(H2O)(2)][Tf2N](9)[Hbet], a tetrameric structure for the manganese(II) and zinc(II) compound, [Mn-4(bet)(10)(H2O)(4)][Tf2N](8) and [Zn-4(bet)(10)(H2O)(2)][Tf2N](8), respectively, a pentameric structure for the nickel(II) compound, [Ni-5(bet)(12)(H2O)(6)][Tf2N](10), an oxo-hydroxo-cluster formation for the lead(II) compound, [(Pb4O)Pb(OH)(bet)(8)(Tf2N)3] [Tf2N](4)center dot MeOH, and a polymeric structure for the silver(I) compound, [Ag-2(bet)(2)(Tf2N)Ag-2(bet)(2)][Tf2N](3). The zwitterionic nature of the betaine ligand and the weakly coordinating ability of the bis(trifluoromethylsulfonyl)imide [Tf2N]- anion facilitates the incorporation of metal ions into oligonuclear and polynuclear metal complexes.
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The complex formation of the uranyl ion, UO22+, with chloride ions in acetonitrile has been investigated by factor analysis of UV-vis absorption and U L-3 edge EXAFS (extended X-ray absorption fine structure) spectra. As a function of increasing [Cl-]/[UO22+] ratio, the five monomeric species [UO2(H2O)(5)](2+), [UO2Cl(H2O)(2)(MeCN)(2)](+), [UO2Cl2(H2O)(MeCN)(2)], [UO2Cl3(MeCN)(2)](-), and [UO2Cl4](2-) have been observed. The distances determined in the first coordination sphere are: U-O-ax = 1.77 angstrom, U-O-H2O = 2.43 angstrom, U-N-MeCN = 2.53 angstrom, and U-Cl = 2.68 angstrom. A crystalline material has been obtained from the intermediate solution with the [Cl-]/[UO22+] ratio of similar to 2, where [UO2Cl2(H2O)(MeCN)(2)] is the dominating species. The crystal structure analysis of this material revealed a tetrameric complex, [(UO2)(4)(mu(2)-Cl)(4)(mu(3)-O)(2)(H2O)(2)(CH3CN)(4)]center dot(CH3CN). The crystal data are: monoclinic, space group P2(1)/n, a 10.6388(5) angstrom, b = 14.8441(5) angstrom, c = 10.8521(5) angstrom, beta = 109.164(5)degrees, and Z = 2. The U(VI) coordination of the solution species [UO2Cl2(H2O)(MeCN)(2)] changes during the crystallization by replacing one MeCN molecule with a bridging mu(3)-O atom in the tetramer.
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Single crystals of mercuric bis(N-imino-methyl-formamidate), Hg(Imf)(2), were obtained from aqueous solutions of 1,2,4-triazole and Hg(NO3)(2)center dot 2H(2)O. The crystal structure [monoclinic, P2(1)/c (no. 14), a = 499.6(2), b = 1051.2(4), c = 711.1(3) pm, beta = 117.55(1)degrees, Z = 2, R, for 890 reflections with I-0 > 2 sigma(I-0): 0.0369] contains linear centrosymmetric Hg(Imf)(2) molecules with Hg-N distances of only 203.5(7)pm. Two plus two intra- and intermolecular nitrogen atoms add to an effective coordination number of 6.
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The dissolution process of metal complexes in ionic liquids was investigated by a multiple-technique approach to reveal the solvate species of the metal in solution. The task-specific ionic liquid betainium bis(trifluoromethylsulfonyl)imide ([Hbet][Tf2N]) is able to dissolve stoichiometric amounts of the oxides of the rare-earth elements. The crystal structures of the compounds [Eu-2(bet)(8)(H2O)(4)][Tf2N](6), [Eu-2(bet)(8)(H2O)(2)][Tf2N](6)center dot 2H(2)O, and [Y-2(bet)(6)(H2O)(4)][Tf2N](6) were found to consist of dimers. These rare-earth complexes are well soluble in the ionic liquids [Hbet][Tf2N] and [C(4)mim]- [Tf2N] (C(4)mim = 1-butyl-3-methylimidazolium). The speciation of the metal complexes after dissolution in these ionic liquids was investigated by luminescence spectroscopy, H-1, C-13, and Y-89 NMR spectroscopy, and by the synchrotron techniques EXAFS (extended X-ray absorption fine structure) and HEXS (high-energy X-ray scattering). The combination of these complementary analytical techniques reveals that the cationic dimers decompose into monomers after dissolution of the complexes in the ionic liquids. Deeper insight into the solution processes of metal compounds is desirable for applications of ionic liquids in the field of electrochemistry, catalysis, and materials chemistry.
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center dot The concept of self-management plans for patients with chronic obstructive pulmonary disease (COPD) is derived from their success in asthma management.
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Complex I (NADH: ubiquinone oxidoreductase) is generally regarded as one of the major sources of mitochondrial reactive oxygen species (ROS). Mitochondrial membranes from the obligate aerobic yeast Yarrowia lipolytica, as well as the purified and reconstituted enzyme, can be used to measure complex I-dependent generation of superoxide (O-2(center dot-)). The use of isolated complex I excludes interference with other respiratory chain complexes and matrix enzymes during superoxide dismutase-sensitive reduction of acetylated cytochrome c. Alternately. hydrogen peroxide formation can be measured by the Amplex Red/horseradish peroxidase assay. Both methods allow the determination of complex I-generated ROS, depending on substrates (NADH, artificial ubiquinones), membrane potential, and active/deactive transition. ROS production by Yorrowia complex I in the
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Ionic liquids are shown to be good solvents for elemental sulfur, selenium, phosphorus and tellurium, and can be designed to maximise the solubility of these elements. The presence of the [S-3](center dot-) radical anion in diluted solutions of sulfur in some ionic liquids has been confirmed, and is the origin of their intense blue colour (cf. lapis lazuli).
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center dot Inappropriate antimicrobial use has been associated with increased morbidity and hospital costs.
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Collagen-related peptide is a selective agonist for the platelet collagen receptor Glycoprotein VI. The triple helical peptide contains ten GPO triplets/strand (single letter amino acid nomenclature, where O is hydroxyproline) and so over-represents GPO compared with native collagen sequence. To investigate the ability of Glycoprotein VI to recognize GPO triplets in a setting more representative of the collagens, we synthesized a set of triple helical peptides containing fewer GPO triplets, varying their number and spacing within an inert (GPP)(n) backbone. The adhesion of recombinant human Glycoprotein VI ectodomain, like that of human platelets, to these peptides increased with their GPO content, and platelet adhesion was abolished by the specific anti-Glycoprotein VI-blocking antibody, 10B12. Platelet aggregation and protein tyrosine phosphorylation were induced only by cross-linked peptides and only those that contained two or more GPO triplets. Such peptides were less potent than cross-linked collagen-related peptide. Our data suggest that both the sequences GPOGPO and GPO center dot center dot center dot center dot center dot center dot center dot center dot center dot GPO represent functional Glycoprotein VI recognition motifs within collagen. Furthermore, we propose that the (GPO)(4) motif can support simultaneous binding of two glycoprotein VI molecules, in either a parallel or anti-parallel stacking arrangement, which could play an important role in activation of signaling.
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Two stable nanofluids comprising of mixed valent copper(I,II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(4)mim][OAc], and copper(II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl) phosphonium acetate, [P-88812][OAc], were synthesised in a facile one-pot reaction from solutions of copper(II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using 13C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)2 in 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc], crystals were obtained that revealed the structure of [C2mim][Cu3(OAc)5(OH)2(H2O)]center dot H2O, indicating the formation of copper hydroxo-clusters in the course of the reaction. Synthesised nanostructures were studied using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Physical properties of the prepared IL-nanofluids were examined using IR and UV-VIS spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and densitometry.
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The electrochemistry of elemental sulfur (S-8) and the polysulfides Na2S4 and Na2S6 has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S-8 in the ionic liquids is different to the behavior reported in some organic solvents, with two reductions and one oxidation peak observed. Supported by in situ UV-vis spectro-electrochemical experiments, the main reduction products of S-8 in [C(4)mim][DCA] ([C(4)mim] = 1-butyl-3-methylimidazolium; DCA = dicyanamide) have been identified as s(6)(2-) and S-4(2-), and plausible pathways for the formation of these species are proposed. Dissociation and/or disproportionation of the polyanions S-6(2-) and S-4(2-) appears to be slow in the ionic liquid, with only small amounts of the blue radical species S3(center dot-) formed in the solutions at r.t., in contrast with that observed in most molecular solvents.
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The formation of various phases during boronizing of silicided molybdenum substrates (MoSi2/Mo) was investigated. Boronizing treatments were conducted in molten salts under an inert gas atmosphere in the 700-1000 degrees C temperature range for 3-7 h. Depending on the process type (non-current or electrochemical) and molten salt temperature, the formation of different boride phases (MoB, Mo2B5, MoB2, MoB4) was observed. At the same time, substantial oxidation of the bulk molybdenum disilicide phase (MoSi2) to the Mo5Si3 phase was observed in non-current boronizing. The oxidation resistance of the coatings was investigated by the weight change in an air-water (2.3 vol.%) mixture at a temperature of 500 degrees C for a period up to 700 h. Results indicated that a two-phase microstructure consisting of the MoSi2, matrix phase with 12-15 wt.% of the MoB4 phase greatly improved the oxidation resistance of the molybdenum substrates. The weight gain rate observed was 6.5 center dot 10(-4) mg/cm(2) h. (c) 2006 Elsevier B.V. All rights reserved.
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The preparation and characterisation are described of a robust, reversible, hydrogen peroxide optical sensor, based on the fluorescent quenching of the dye ion-pair [Ru(bpy)(3)(2+)(Ph4B-)(2)], by O-2 produced by the catalytic breakdown of H2O2, utilizing the inorganic catalyst RuO2 center dot xH(2)O. The main feature of this system is the one-pot formulation of a coating ink that, when dried, forms an active single-layer fluorescence-based H2O2 sensor, demonstrably capable of detecting H2O2 over the range of 0.01 to 1 M, with a relative standard deviation of ca. 4% and a calculated lower limit of detection of 0.1 mM. These sensors are sterilisable, using dry-heat, and stable when stored over 40 days, without exhibiting any loss in sensitivity or response characteristics.