12,607 research outputs found
Thyroid hormone receptors and ligand, tissue distribution and sexual behavior
The thyroid hormones (THs) triiodothyronine (T3) and tetraiodothyronine,
or thyroxine (T4), not only dramatically impact on
development and differentiation, but also on the sexual and
reproductive function. There is large body of literature, in fact, on
the effects of THs on the reproductive function in both humans
(Poppe and Velkeniers, 2004; Wajner et al., 2009) and animals
(Hapon et al., 2010; Nelson et al., 2011).
For a long time the gonads were thought to be unresponsive to
THs, but TH receptors (TR) were discovered in rat (Jannini et al.,
1990; Palmero et al., 1988) and then in human testis (Jannini
et al., 2000). In women, the association of menstrual disturbance
with thyroid disease was described as early as 1840 by von Basedow,
but the discovery of TRs in the ovary was carried out at the
end of last century (Wakim et al., 1994b). Therefore, the link between
thyroid and reproductive function was well established.
Since then, research has shown that thyroid dysfunction is associated
with an adverse effect on fertility, both in men (Wagner et al.,
2009) and women (Dittrich et al., 2011). There is also evidence that
THs can affect the sex steroid hormone axis (Bagamasbad and
Denver, 2011), consequently sexual hormones and the pituitary
gland can mediate the action of THs on the reproductive
physiology.
While the effects of THs on fertility have been widely studied,
little is known about their influence on sexual function. In the last
few years, an increasing number of evidences have shown the influence
of THs on male sexual function, particularly on ejaculation
control as well on desire and erectile function (Carani et al., 2005;
Corona et al., 2012b; Di Sante et al., 2016). The female sexual
function and the relationship with thyroid function is still less
studied. Furthermore, studies conducted on animals have shown
the presence of TRs in the male (Carosa et al., 2010) and female
genitalia (Rodriguez-Castelan et al., 2017). Moreover, knockout
mice for TRs showed alterations in sexual behavior (Dellovade et al.,
2000).
The purpose of this review is to summarize and discuss the
available data on the influence of THs on male and female sexual
function to understand the molecular mechanisms of the influence
of the thyroid gland on sexual behavior and function
Nilsson-SU3 selfconsistency in heavy N=Z nuclei
It is argued that there exist natural shell model spaces optimally adapted to
the operation of two variants of Elliott' SU3 symmetry that provide accurate
predictions of quadrupole moments of deformed states. A selfconsistent
Nilsson-like calculation describes the competition between the realistic
quadrupole force and the central field, indicating a {\em remarkable stability
of the quadruplole moments}---which remain close to their quasi and pseudo SU3
values---as the single particle splittings increase. A detailed study of the
even nuclei from Ni to Cd reveals that the region of
prolate deformation is bounded by a pair of transitional nuclei Kr and
Mo in which prolate ground state bands are predicted to dominate, though
coexisting with oblate ones,Comment: Replacement I) Title simplified. II) Major revision: structure of
paper kept but two thirds totally rewritten (same number of pages); 20
references adde
Isospin-breaking interactions studied through mirror energy differences
Background: Information on charge-dependent (i.e., isospin-non-conserving) interactions is extracted from excited states of mirror nuclei.
Purpose: Specifically, the purpose of the study is to extract effective isovector (Vpp 12Vnn) interactions which, in general, can either be of Coulomb or nuclear origin.
Methods: A comprehensive shell-model description of isospin-breaking effects is used to fit data on mirror energy differences in the A = 42\u201354 region. The angular-momentum dependence of isospin-breaking interactions was determined from a systematic study of mirror energy differences.
Results: The results reveal a significant isovector term, with a very strong spin dependence, beyond that expected of a two-body Coulomb interaction.
Conclusions: The isospin-breaking terms that are extracted have a J dependence that is not consistent with the known CSB properties of the bare nucleon-nucleon interaction
Neutron Skins and Halo Orbits in the sd and pf Shells
open3siThe strong dependence of Coulomb energies on nuclear radii makes it possible to extract the latter from
calculations of the former. The resulting estimates of neutron skins indicate that two mechanisms are
involved. The first one --isovector monopole polarizabilityâamounts to noting that when a particle is
added to a system it drives the radii of neutrons and protons in different directions, tending to equalize the
radii of both fluids independently of the neutron excess. This mechanism is well understood and the Duflo-
Zuker (small) neutron skin values derived 14 years ago are consistent with recent measures and estimates.
The alternative mechanism involves halo orbits whose huge sizes tend to make the neutron skins larger and
have a subtle influence on the radial behavior of sd and f shell nuclei. In particular, they account for the
sudden rise in the isotope shifts of nuclei beyond N=28 and the near constancy of radii in the A=40â56
region. This mechanism, detected here for the first time, is not well understood and may well go beyond the
Efimov physics usually associated with halo orbits.openBonnard, JEREMY CHRISTIAN FREDERIC; Lenzi, SILVIA MONICA; Zuker, A. P.Bonnard, JEREMY CHRISTIAN FREDERIC; Lenzi, SILVIA MONICA; Zuker, A. P
Excitation of the GDR and the Compressional Isoscalar Dipole State by alpha scattering
The excitation of the isovector giant dipole resonance (GDR) by alpha
scattering is investigated as a method of probing the neutron excess in exotic
nuclei. DWBA calculations are presented for 28O and 70Ca and the interplay of
Coulomb and nuclear excitation is discussed. Since the magnitude of the Coulomb
excitation amplitude is strongly influenced by the Q-value, the neutron excess
plays an important role, as it tends to lower the energy of the GDR. The
excitation of the compressional isoscalar dipole state in 70Ca by alpha
scattering is also investigated. It is shown that the population of this latter
state may be an even more sensitive probe of the neutron skin than the
isovector GDR.Comment: 7 pages, 5 figures, Latex2
Are the therapeutic strategies in anorexia of ageing effective on nutritional status? A systematic review with meta-analysis
BACKGROUND:
Anorexia of ageing (AA) may be considered as a risk factor for frailty and has an important impact on quality of life, morbidity and mortality.
METHODS:
A systematic review and a meta-analysis were performed to summarise the results from several trials on the effectiveness of treatments in AA, as associated with depression, sensory impairment of taste and smell, decreased appetite or early satiety, and disability. Eligible studies were required to report baseline and follow-up values, the mean change (â-change) from baseline, and/or the mean difference among intervention groups versus control group, concerning food intake (kcal/daily) and/or nutritional outcomes, such as body weight, body mass index, albumin and Mini Nutritional Assessment.
RESULTS:
The systematic review included 20 papers based on different therapeutic approaches concerning food intake and/or nutritional outcomes. The results of the meta-analysis indicate that the interventions for AA have an important impact on body weight [+1.59 kg; 95% confidence interval (CI) = 1.48-+1.71 kg; P < 0.001) and on energy intake (+56.09 kcal; 95% CI = -54.05 to +166.25 kcal; P = 0.32). Regarding secondary outcomes, it was not possible to meta-analyse the limited amount of data availab le.
CONCLUSIONS:
The different variants of AA need to be defined because diverse therapeutic approaches are available. A more precise definition of the functional impairments associated with AA may allow a more correct decision about the most appropriate therapy to be prescribed. Moreover, this may allow for a more effective performance of the different therapeutic approaches once they are better targeted to the different scenarios of AA
Coulomb displacement energies, energy differenced and neutron skins
A Fock space representation of the monopole part of the Coulomb potential is
presented. Quantum effects show through a small orbital term in . Once
it is averaged out, the classical electrostatic energy emerges as an
essentially exact expression, which makes it possible to eliminate the
Nolen-Schiffer anomaly, and to estimate neutron skins and the evolution of
radii along yrast states of mirror nuclei. The energy differences of the latter
are quantitatively reproduced by the monopole term and a schematic multipole
one.Comment: 4 pages, 3 figures, Revte
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