1,011 research outputs found

    Profile, antioxidant potential, and applicability of phenolic compounds extracted from Spirulina platensis

    Get PDF
    This work aimed at an investigation of the profile of free phenolic compounds (PC) of Spirulina platensis and assesses their antioxidant potential, applying them as a natural conservative in minimally processed apples. The phenolic extract showed 396 &µg g-1 gallic acid, 347 µg g-1 of caffeic acid, 54 µg g-1 salicylic acid and 3.5 µg g-1 trans-1-cinmamic a total of 608 µg PC g-1 of S. platensis. With the use of PC, it was possible to inhibit the radical DPPH over 180 min with IC50 of PC 202 µg mL-1. The inhibition of polyphenol oxidase and peroxidase of PC were 19.9 and 9.7%. In addition, verifying the constants Km and Vmax, it was concluded that  inhibition of the peroxidase and polyphenol occurs in an uncompetitive manner. Application of crude extract of PC under minimally processed apples showed  inhibition of browning by 40%. The general acceptance of apples was not affected by the addition of PC.Key words: Apple, enzymatic browning, peroxidase, phenols, polyphenol oxidase

    Psychometric characteristics of DLQI-BRA and Skindex-16 to measure the impact of dermatological diseases on quality of life in Brazilian patients

    Get PDF
    OBJECTIVE: To compare the psychometric performance of the Dermatology Life Quality Index (DLQI-BRA) and Skindex-16 to assess quality of life (QoL) in Brazilian patients with dermatological diseases. METHODS: This was a cross-sectional study carried out in a dermatology outpatient clinic of the São Paulo State University, with 188 patients with dermatological diseases. QoL was evaluated using the Dermatology Life Quality Index (DLQI-BRA) and Skindex-16. Cronbach’s alpha and Intraclass Correlation for Perfect Concordance (ICC) were used to analyse the reliability and temporal stability, respectively. RESULTS: A positive correlation was found between the total Skindex-16 score and DLQI-BRA (0.75). Both instruments showed a significant (p0,7), but Skindex-16 displayed the highest Cronbach alpha (0.94; CI = 0.93–0.95). CONCLUSION: Both instruments tested showed a good psychometric performance assessing QoL in patients with skin dermatoses. The instruments displayed reliability and temporal stability as well as responsiveness

    Gauge symmetry and W-algebra in higher derivative systems

    Full text link
    The problem of gauge symmetry in higher derivative Lagrangian systems is discussed from a Hamiltonian point of view. The number of independent gauge parameters is shown to be in general {\it{less}} than the number of independent primary first class constraints, thereby distinguishing it from conventional first order systems. Different models have been considered as illustrative examples. In particular we show a direct connection between the gauge symmetry and the W-algebra for the rigid relativistic particle.Comment: 1+22 pages, 1 figure, LaTeX, v2; title changed, considerably expanded version with new results, to appear in JHE

    Digital Quantum Simulation of the Statistical Mechanics of a Frustrated Magnet

    Full text link
    Many interesting problems in physics, chemistry, and computer science are equivalent to problems of interacting spins. However, most of these problems require computational resources that are out of reach by classical computers. A promising solution to overcome this challenge is to exploit the laws of quantum mechanics to perform simulation. Several "analog" quantum simulations of interacting spin systems have been realized experimentally. However, relying on adiabatic techniques, these simulations are limited to preparing ground states only. Here we report the first experimental results on a "digital" quantum simulation on thermal states; we simulated a three-spin frustrated magnet, a building block of spin ice, with an NMR quantum information processor, and we are able to explore the phase diagram of the system at any simulated temperature and external field. These results serve as a guide for identifying the challenges for performing quantum simulation on physical systems at finite temperatures, and pave the way towards large scale experimental simulations of open quantum systems in condensed matter physics and chemistry.Comment: 7 pages for the main text plus 6 pages for the supplementary material

    Adaptation and validation of the Patient Expectations and Satisfaction with Prenatal Care instrument among Brazilian pregnant women

    Get PDF
    Objective: to adapt and validate the Patient Expectations and Satisfaction with Prenatal Care instrument for use in Brazil. It contains 41 items divided into two dimensions: expectations and satisfaction. The adapted version was submitted to analysis for stability, convergent construct validity, and internal consistency (Cronbach’s alpha) for distinct groups and dimensions. Method: 119 pregnant women receiving prenatal care were interviewed and 26 of these women answered the instrument twice (retest). Internal consistency was appropriate (Cronbach’s alpha ≥ 0.70); test-retest presented strong correlation (r=0.82; p<0.001) for the domain expectations and moderate correlation (r=0.66; p<0.001) for the satisfaction domain. The analysis confirmed that the instrument’s adapted version is valid in the studied group. Results: there is strong evidence for the validity and reliability of the instrument’s adaptation. Conclusion: the instrument needs to be tested in groups of pregnant women with different social characteristics.CAPESCAPE

    Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

    Get PDF
    A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%
    • …
    corecore