1,152 research outputs found

    Capillary electrophoresis-mass spectrometry characterisation of secondary metabolites from the antihyperglycaemic plant Genista tenera

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    Genista tenera is endemic to the Portuguese island of Madeira, where an infusion of the aerial parts of the plant is used in folk medicine as an antidiabetic agent. Consequently the medicinal properties of the secondary metabolites of this plant have been the subject of an ongoing study. A recently reported LC-MS method using a 100 min separation allowed identification of five flavonoid components in an extract of the aerial parts of this plant. In order to obtain additional information on the range and complexity of the plant’s secondary metabolite components a CE-MS method has been developed and applied for the analysis of an extract of G. tenera. Twenty-six different components are distinguished in an analysis time of only 10 min. Results demonstrate that CE-MS/MS rapidly generates data complementary to those obtainable by LC-MS/MS and is particularly suited to the analysis of plant metabolites where concentration is not limiting.BBSRC, University of York, Treaty of Windsor Anglo-Portuguese joint research programme, Thermo Electron, Analytical Chemistry Trust Fund, Royal Society of Chemistry Analytical Division, Engineering and Physical Sciences Research Council (EPSRC)info:eu-repo/semantics/publishedVersio

    Three-dimensional analysis of jaw kinematic alterations in patients with chronic TMD - disc displacement with reduction

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    The study investigated whether chronic TMD patients with disc displacement with reduction (DDR), performing non-assisted maximum jaw movements, presented any changes in their mandibular kinematics with respect to an age-matched control group. Moreover, it was examined whether jaw kinematics and a valid clinic measure of oro-facial functional status have significant associations. Maximum mouth opening, mandible protrusion and bilateral laterotrusions were performed by 20 patients (18 women, 2 men; age, 18-34 years) and 20 healthy controls (17 women, 3 men; age, 20-31 years). The three-dimensional coordinates of their mandibular interincisor and condylar reference points were recorded by means of an optoelectronic motion analyser and were used to quantitatively assess their range of motion, velocity, symmetry and synchrony. Three functional indices (opening-closing, mandibular rototranslation, laterotrusion - right and left - and protrusion) were devised to summarise subject's overall performance, and their correlation with the outcome of a clinical protocol, the oro-facial myofunctional evaluation with scores (OMES), was investigated. TMD patients were able to reach maximum excursions of jaw movements comparable to healthy subjects' performances. However, their opening and closing mandibular movements were characterised by remarkable asynchrony of condylar translation. They had also reduced jaw closing velocity and asymmetric laterotrusions. The functional indices proved to well summarise the global condition of jaw kinematics, highlighting the presence of alterations in TMD-DDR patients, and were linearly correlated with the oro-facial functional status. The jaw kinematic alterations seem to reflect both oro-facial motor behaviour adaptation and a DDR-related articular impairment

    Planning Runtime Adaptation through Pragmatic Goal Model

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    Adaptivity is a capability that enables a system to choose amongst various alternatives to satisfy or maintain the satisfaction of certain requirements. The criteria of requirements satisfaction could be pragmatic and context-dependent. Contextual Goal Models (CGM) capture the power of context on banning or allowing certain alternatives to reach requirements (goals) and also deciding the quality of those alternatives with regards to certain quality measures (softgoals). It is used to depict facets of the decision making strategy and rationale of an adaptive system at the preliminary level of requirements. In this paper we argue the case for pragmatic requirements and extend the CGM with additional constructs to capture them and allow their analysis. We also develop an automated analysis which aids the planning and scheduling of tasks execution to meet pragmatic goals. Moreover, we evaluate our modelling and analysis regarding correctness and performance. Such an evaluation showed the applicability of the approach and its usefulness in aiding sensible decisions. It has also shown its capability to do so in a time short enough to suit run-time adaptation decision making

    Perspetivas de utilização de nanomateriais em nanodiagnóstico

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    Conventional diagnostic methods are exclusively focused on the detection of the symptoms associated to a given pathology. Any process able to determine with anticipation the occurrence of a disease, inclusively before the first symptoms, or providing the means to predict the possibility of occurrence of that disease, would significantly reinforce the effectiveness of the therapy allowing, at the same time, the establishment of prevention measures to avoid its progression. Much of the worldwide health research aims at the development of expedite devices or strategies capable of carrying out the monitoring of first level signs, or able to early detect and quantify biomarkers, usually at very low concentrations, associated to a given illness. In the search for alternative diagnostic methods able to overcome the limitations of available technology nanomaterials assume a decisive role and anticipate extremely promising developments in healthcare medicine. Os métodos de diagnósticos convencionais estão exclusivamente empenhados na deteção de sintomas associados a uma dada patologia. Qualquer processo que permita determinar o mais antecipadamente possível a ocorrência da doença, inclusive antes de surgirem os primeiros indícios, ou que permita avaliar o risco da doença ocorrer, reforçaria significativamente as hipóteses de sucesso da terapia e tornaria até praticável tomar medidas preventivas para evitar a sua progressão. Muita da investigação em curso na área da medicina passa pelo desenvolvimento de estratégias ou dispositivos capazes de efetuar a monitorização, o mais antecipadamente possível, destes indícios, ou então capazes de detetar e quantificar precocemente marcadores biológicos, usualmente em concentrações muito baixas, associados a uma dada patologia. Na pesquisa por métodos de diagnósticos alternativos, aptos a ultrapassar algumas das limitações dos métodos atuais, os nanomateriais assumem um papel decisivo e abrem perspetivas de desenvolvimento extremamente promissoras para a área do nanodiagnóstico.

    Magnetic phenomena in 5d transition metal nanowires

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    We have carried out fully relativistic full-potential, spin-polarized, all-electron density-functional calculations for straight, monatomic nanowires of the 5d transition and noble metals Os, Ir, Pt and Au. We find that, of these metal nanowires, Os and Pt have mean-field magnetic moments for values of the bond length at equilibrium. In the case of Au and Ir, the wires need to be slightly stretched in order to spin polarize. An analysis of the band structures of the wires indicate that the superparamagnetic state that our calculations suggest will affect the conductance through the wires -- though not by a large amount -- at least in the absence of magnetic domain walls. It should thus lead to a characteristic temperature- and field dependent conductance, and may also cause a significant spin polarization of the transmitted current.Comment: 7 pages, 5 figure

    Oral Angiotensin-(1–7) prevented obesity and hepatic inflammation by inhibition of resistin/TLR4/MAPK/NF-κB in rats fed with high-fat diet

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    AbstractObesity is characterized by a pro-inflammatory state commonly associated with type 2 diabetes and fat-liver disease. In the last few years, different studies pointed out the role of Angiotensin (Ang)-(1–7) in the metabolic regulation. The aim of the present study was to evaluate the effect of oral-administration of Ang-(1–7) in metabolism and inflammatory state of high-fat feed rats. Twenty-four male Sprague Dawley rats were randomized into three groups: High Fat Diet (HFD); Standard Diet (ST); High Fat Diet+Angiotensin-(1–7) [HFD+Ang-(1–7)]. Glycemic profile was evaluated by glucose tolerance and insulin sensitivity tests, plasmatic glucose and insulin. Cholesterol, HDL and triglycerides analyses presented lipidic profile. RT-PCR evaluated mRNA expression to ACE, ACE2, resistin, TLR4, IL-6, TNF-α and NF-κB genes. The main results showed that oral Ang-(1–7) decreased body weight and abdominal fat-mass. In addition, HFD+Ang-(1–7) treated rats presented enhanced glucose tolerance, insulin-sensitivity and decreased plasma-insulin levels, as well as a significant decrease in circulating lipid levels. These alterations were accompanied by a marked decreased expression of resistin, TLR4, ACE and increased ACE2 expression in liver. Furthermore, Ang-(1–7) decreases phosphorylation of MAPK and increases NF-κB expression. These alterations diminished expression of interleukin-6 and TNF-α, ameliorate inflammatory state in liver. In summary, the present study showed that oral-treatment with Ang-(1–7) in high-fat feed rats improved metabolism down-regulating resistin/TLR4/NF-κB-pathway

    Influence of dietary Chlorella vulgaris and carbohydrate-active enzymes on growth performance, meat quality and lipid composition of broiler chickens

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    Article in pressHerein, we investigated the effect of Chlorella vulgaris as ingredient (10% of incorporation) in broiler diets, supplemented or not with 2 formulations of Carbohydrate-Active enZymes (CAZymes; Rovabio Excel AP and a mixture of recombinant CAZymes, composed by an exo-b-glucosaminidase, an alginate lyase, a peptidoglycan N-acetylmuramic acid deacetylase and a lysozyme), on growth performance, meat quality, fatty acid composition, oxidative stability, and sensory traits. One hundred twenty 1-day-old Ross 308 male birds were randomly assigned to one of the 4 experimental diets (n 5 30): corn-soybean meal–basal diet (control), basal diet with 10% C. vulgaris (CV), CV supplemented with 0.005% of a commercialCAZymecocktail (Rovabio Excel AP), (CV1R), and CV supplemented with 0.01% of a 4- CAZyme mixture previously selected (CV 1 M) during the experimental period lasted from day 21 to day 35. Body weight gain and feed conversion rate of broilers were not affected by C. vulgaris but digesta viscosity increased more than 2-fold (P , 0.001) relative to the control. In addition, neither cooking loss, shear force, juiciness, flavor nor off-flavor was impaired by dietary treatments (P.0.05). By contrast, the dietary C. vulgaris increased tenderness, yellowness (b*) and total carotenoids in breast and thigh meats. However, no additional protective effect against lipid oxidation was observed in meat with the inclusion of microalga. Chlorella vulgaris, independently of CAZymes, had a minor impact on meat fatty acid composition but improved the proportion of some beneficial fatty acids. In summary, our data indicate a slight improvement of broiler meat quality and lipid nutritional value, without impairment of broilers’ growth performance, thus supporting the usefulness of this microalga in poultry diets, up to this high level of incorporation. By contrast, the selected CAZyme mixtures used do not significantly improve the release of microalga nutrients in poultry diets, through the disruption of microalga cell wall, which warrants further researchinfo:eu-repo/semantics/acceptedVersio

    BPS Condensates, Matrix Models and Emergent String Theory

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    A prescription is given for computing anomalous dimensions of single trace operators in SYM at strong coupling and large NN using a reduced model of matrix quantum mechanics. The method involves treating some parts of the operators as "BPS condensates" which, in certain limit, have a dual description as null geodesics on the S5S^5. In the gauge theory, the condensate is similar to a representative of the chiral ring and it is described by a background of commuting matrices. Excitations around these condensates correspond to excitations around this background and take the form of "string bits" which are dual to the "giant magnons" of Hofman and Maldacena. In fact, the matrix model approach gives a {\it quantum} description of these string configurations and explains why the infinite momentum limit suppresses the quantum effects. This method allows, not only to derive part of the classical sigma model Hamiltonian of the dual string (in the infinite momentum limit), but also its quantum canonical structure. Therefore, it provides an alternative method of testing the AdS/CFT correspondence without the need of integrability.Comment: 36 pages, 1 figure, 2 appendices, v2: references adde

    Giant Gravitons - with Strings Attached (III)

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    We develop techniques to compute the one-loop anomalous dimensions of operators in the N=4{\cal N}=4 super Yang-Mills theory that are dual to open strings ending on boundstates of sphere giant gravitons. Our results, which are applicable to excitations involving an arbitrary number of open strings, generalize the single string results of hep-th/0701067. The open strings we consider carry angular momentum on an S3^3 embedded in the S5^5 of the AdS5×_5\timesS5^5 background. The problem of computing the one loop anomalous dimensions is replaced with the problem of diagonalizing an interacting Cuntz oscillator Hamiltonian. Our Cuntz oscillator dynamics illustrates how the Chan-Paton factors for open strings propagating on multiple branes can arise dynamically.Comment: 66 pages; v2: improved presentatio

    Current-Induced Effects in Nanoscale Conductors

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    We present an overview of current-induced effects in nanoscale conductors with emphasis on their description at the atomic level. In particular, we discuss steady-state current fluctuations, current-induced forces, inelastic scattering and local heating. All of these properties are calculated in terms of single-particle wavefunctions computed using a scattering approach within the static density-functional theory of many-electron systems. Examples of current-induced effects in atomic and molecular wires will be given and comparison with experimental results will be provided when available.Comment: revtex, 10 pages, 8 figure
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