555 research outputs found
Composición química-funcional de aceites de Terminalia catappa de diferentes variedades
This study aimed to extract and physical-chemically characterize Terminalia catappa L. kernel oil from purple (CR) and yellow (CA) varieties. Physical-chemical parameters, composition of fatty acids, nutritional quality indices, bioactive compounds and antioxidant capacity of both oil varieties were evaluated according to the literature. Both oils presented low levels of acidity and peroxides, besides the predominance of unsaturated fatty acids, ~63% of oleic and ~26% of linoleic acids, which influenced its nutritional indices. The CR oil variety exhibited a higher content in anthocyanin (18.3 ± 1.5 mg·100 g-1), ascorbic acid (68.4 ± 2.02 mg·100 g-1) and total polyphenol contents (152.3 ± 2.4 mg GAE·g-1), and a good antioxidant activity (38.6 ± 2.2 μg TE·g-1) determined by TEAC assay, when compared to the CA oil (p < 0.05). Therefore, the results confirm the importance of T. catappa as a lipid source for human consumption to be used in the development of food products.El objetivo de este estudio fue extraer y caracterizar físico-químicamente aceite de semilla de Terminalia catappa de las variedades violeta (CR) y amarilla (CA). Se evaluaron parámetros fisicoquímicos, composición de ácidos grasos, índices de calidad nutricional, compuestos bioactivos y capacidad antioxidante de ambas variedades de aceite de acuerdo con a la literatura. Como resultado, ambos aceites presentaron bajos niveles de acidez y peróxidos, y predominio de ácidos grasos insaturados, ~63% de ácido oleico y ~26% de ácido linoleico, lo cual influyó en su perfil nutricional. La variedad de aceite CR presentó un mayor contenido de antocianina (18,3 ± 1,5 mg·100 g-1), ácido ascórbico (68,4 ± 2,02 mg·100 g-1) y contenido total de polifenoles (152,3 ± 2,4 mg GAE·g-1), y una alta actividad antioxidante (38,6 ± 2,2 μg TE·g-1) determinado por ensayo TEAC, en comparación con el aceite CA (p<0.05). En conclusión, los resultados presentados refuerzan la importancia de T. catappa como fuente de lípidos para la ingesta humana y para su uso en el desarrollo de productos alimenticios
Entanglement in the One-dimensional Kondo Necklace Model
We discuss the thermal and magnetic entanglement in the one-dimensional Kondo
necklace model. Firstly, we show how the entanglement naturally present at zero
temperature is distributed among pairs of spins according to the strength of
the two couplings of the chain, namely, the Kondo exchange interaction and the
hopping energy. The effect of the temperature and the presence of an external
magnetic field is then investigated, being discussed the adjustment of these
variables in order to control the entanglement available in the system. In
particular, it is indicated the existence of a critical magnetic field above
which the entanglement undergoes a sharp variation, leading the ground state to
a completely unentangled phase.Comment: 8 pages, 13 EPS figures. v2: four references adde
Large scale numerical investigation of excited states in poly(phenylene)
A density matrix renormalisation group scheme is developed, allowing for the
first time essentially exact numerical solutions for the important excited
states of a realistic semi-empirical model for oligo-phenylenes. By monitoring
the evolution of the energies with chain length and comparing them to the
experimental absorption peaks of oligomers and thin films, we assign the four
characteristic absorption peaks of phenyl-based polymers. We also determine the
position and nature of the nonlinear optical states in this model.Comment: RevTeX, 10 pages, 4 eps figures included using eps
Double quantum dot turnstile as an electron spin entangler
We study the conditions for a double quantum dot system to work as a reliable
electron spin entangler, and the efficiency of a beam splitter as a detector
for the resulting entangled electron pairs. In particular, we focus on the
relative strengths of the tunneling matrix elements, the applied bias and gate
voltage, the necessity of time-dependent input/output barriers, and the
consequence of considering wavepacket states for the electrons as they leave
the double dot to enter the beam splitter. We show that a double quantum dot
turnstile is, in principle, an efficient electron spin entangler or
entanglement filter because of the exchange coupling between the dots and the
tunable input/output potential barriers, provided certain conditions are
satisfied in the experimental set-up.Comment: published version; minor error correcte
Placental expression of eNOS, iNOS and the major protein components of caveolae in women with pre-eclampsia
Caveolae regulate many cardiovascular functions and thus could be of interest in relation to pre-eclampsia, a pregnancy specific disorder characterised by hypertension and proteinuria. We examined placental mRNA and protein expression/localisation of the caveolae components Caveolin 1-3, Cavin 1-4 as well as eNOS/ iNOS in normotensive control (n=24) and pre-eclamptic pregnancies (n=19). Placental mRNA expression of caveolin-1, cavin 1-3, was lower and eNOS expression was increased in pre-eclampsia (P<0.05 for all). Additionally Caveolin-1 protein expression was also reduced in pre-eclampsia (P=0.007); this could be an adaptive response in pre-eclampsia, possibly to attenuate the oxidative stress/inflammation
An analysis of the FIR/RADIO Continuum Correlation in the Small Magellanic Cloud
The local correlation between far-infrared (FIR) emission and radio-continuum
(RC) emission for the Small Magellanic Cloud (SMC) is investigated over scales
from 3 kpc to 0.01 kpc. Here, we report good FIR/RC correlation down to ~15 pc.
The reciprocal slope of the FIR/RC emission correlation (RC/FIR) in the SMC is
shown to be greatest in the most active star forming regions with a power law
slope of ~1.14 indicating that the RC emission increases faster than the FIR
emission. The slope of the other regions and the SMC are much flatter and in
the range of 0.63-0.85. The slopes tend to follow the thermal fractions of the
regions which range from 0.5 to 0.95. The thermal fraction of the RC emission
alone can provide the expected FIR/RC correlation. The results are consistent
with a common source for ultraviolet (UV) photons heating dust and Cosmic Ray
electrons (CRe-s) diffusing away from the star forming regions. Since the CRe-s
appear to escape the SMC so readily, the results here may not provide support
for coupling between the local gas density and the magnetic field intensity.Comment: 19 pages, 7 Figure
Decoherence in trapped ions due to polarization of the residual background gas
We investigate the mechanism of damping and heating of trapped ions
associated with the polarization of the residual background gas induced by the
oscillating ions themselves. Reasoning by analogy with the physics of surface
electrons in liquid helium, we demonstrate that the decay of Rabi oscillations
observed in experiments on 9Be+ can be attributed to the polarization phenomena
investigated here. The measured sensitivity of the damping of Rabi oscillations
with respect to the vibrational quantum number of a trapped ion is also
predicted in our polarization model.Comment: 26 pdf pages with 5 figures, http://www.df.ufscar.br/~quantum
Toward an internally consistent astronomical distance scale
Accurate astronomical distance determination is crucial for all fields in
astrophysics, from Galactic to cosmological scales. Despite, or perhaps because
of, significant efforts to determine accurate distances, using a wide range of
methods, tracers, and techniques, an internally consistent astronomical
distance framework has not yet been established. We review current efforts to
homogenize the Local Group's distance framework, with particular emphasis on
the potential of RR Lyrae stars as distance indicators, and attempt to extend
this in an internally consistent manner to cosmological distances. Calibration
based on Type Ia supernovae and distance determinations based on gravitational
lensing represent particularly promising approaches. We provide a positive
outlook to improvements to the status quo expected from future surveys,
missions, and facilities. Astronomical distance determination has clearly
reached maturity and near-consistency.Comment: Review article, 59 pages (4 figures); Space Science Reviews, in press
(chapter 8 of a special collection resulting from the May 2016 ISSI-BJ
workshop on Astronomical Distance Determination in the Space Age
Electron irradiation of nuclear graphite studied by transmission electron microscopy and electron energy loss spectroscopy
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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