3,239 research outputs found
Metabolomics application in maternal-fetal medicine
Metabolomics in maternal-fetal medicine is still an "embryonic" science. However, there is already an increasing interest in metabolome of normal and complicated pregnancies, and neonatal outcomes. Tissues used for metabolomics interrogations of pregnant women, fetuses and newborns are amniotic fluid, blood, plasma, cord blood, placenta, urine, and vaginal secretions. All published papers highlight the strong correlation between biomarkers found in these tissues and fetal malformations, preterm delivery, premature rupture of membranes, gestational diabetes mellitus, preeclampsia, neonatal asphyxia, and hypoxic-ischemic encephalopathy. The aim of this review is to summarize and comment on original data available in relevant published works in order to emphasize the clinical potential of metabolomics in obstetrics in the immediate future
Controlled flavor violation in the MSSM from a unified flavor symmetry
We study the phenomenology of a unified supersymmetric theory with a flavor
symmetry . The model accommodates quark and lepton masses, mixing
angles and CP phases. In this model, the Dirac and Majorana mass matrices have
a unified texture zero structure in the entry that leads to the
Gatto-Sartori-Tonin relation between the Cabibbo angle and ratios of the masses
in the quark sectors, and to a natural departure from zero of the
angle in the lepton sector. We derive the flavor structures
of the trilinears and soft mass matrices, and show their general
non-universality. This causes large flavor violating effects. As a consequence,
the parameter space for this model is constrained, allowing it to be
(dis)proven by flavor violation searches in the next decade. Although the
results are model specific, we compare them to previous studies to show similar
flavour effects (and associated constraints) are expected in general in
supersymmetric flavor models, and may be used to distinguish them.Comment: 21 pages, 6 figure
Leptogenesis in with a Universal Texture Zero
We investigate the possibility of viable leptogenesis in an appealing
model with a universal texture zero in the (1,1) entry. The model
accommodates the mass spectrum, mixing and CP phases for both quarks and
leptons and allows for grand unification. Flavoured Boltzmann equations for the
lepton asymmetries are solved numerically, taking into account both and
right-handed neutrino decays. The -dominated scenario is successful
and the most natural option for the model, with GeV,
and , which constrains the parameter space of the
underlying model and yields lower bounds on the respective Yukawa couplings.
Viable leptogenesis is also possible in the -dominated scenario, with the
asymmetry in the electron flavour protected from washout by the texture
zero. However, this occurs in a region of parameter space which has a stronger
mass hierarchy , and relatively close to , which
is not a natural expectation of the model.Comment: v2: 20 pages, 2 figures. Version accepted in JHE
The Chemical Composition of an Extrasolar Minor Planet
We report the relative abundances of 17 elements in the atmosphere of the
white dwarf star GD 362, material that, very probably, was contained previously
in a large asteroid or asteroids with composition similar to the Earth/Moon
system. The asteroid may have once been part of a larger parent body not unlike
one of the terrestrial planets of our solar system.Comment: ApJ, in pres
Density functional theory calculations of the stress of oxidised (1 1 0) silicon surfaces
The measurement of the lattice-parameter of silicon by x-ray interferometry assumes the use of strain-free crystals. This might not be the case because surface relaxation, reconstruction, and oxidation cause strains without the application of any external force. In a previous work, this intrinsic strain was estimated by a finite element analysis, where the surface stress was modeled by an elastic membrane having a 1 N m(-1) tensile strength. The present paper quantifies the surface stress by a density functional theory calculation. We found a value exceeding the nominal value used, which potentially affects the measurement accuracy
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