1,219 research outputs found
Observational Constraints on Axion(s) with a Cosmological Constant
The present work deals with a dark energy model that has an oscillating
scalar field potential along with a cosmological constant (CC). The oscillating
part of the potential represents the contribution of a light axion field in the
dark energy that has its origin in the String-Axiverse scenario. The model has
been confronted with the latest cosmological observations. The results show
that a sub-Planckian value of the axion field decay constant is consistent at
1 confidence level. The oscillating feature in the scalar field
evolution and in the equation of state for the dark energy can be observed at
2 confidence interval. It is also observed that cluster number counts
in this axion model are suppressed compared to the CDM and this
suppression is enhanced for the sub-Planckian values for the axion decay
constant.Comment: 18 pages, LateX style. Comments welcom
Supersolid Stacks in Antidipolar Bose-Einstein Condensates
We theoretically investigate a novel supersolid structure taking the form of
stacked, disk-shaped superfluid droplets connected via a dilute superfluid, in
an antidipolar condensate. A phase diagram is determined for varying the
particle number and scattering length, identifying the regions of a regular
dipolar superfluid, supersolid stacks, and isolated stacked disk-shaped
droplets in an experimentally realizable trapping potential. The collective
Bogoliubov excitation spectrum across the superfluid-supersolid phase
transition is studied, and the transition point is found to be associated with
the breaking of the degeneracy of the two lowest-lying modes. The dynamical
generation of the supersolid stacks is also investigated by ramping down the
scattering length across the phase transition. Moreover, we have studied the
impact of vortex-line penetration on the phase transition. We have found that
the presence of a vortex line causes the supersolid region to move towards
weaker contact interactions. Our detailed numerical simulations highlight that
an antidipolar condensate can create such supersolid stacks within an
experimentally reachable parameter regime.Comment: 12 pages, 9 figure
Role of Androgens in Cardiovascular Diseases in Men: A Comprehensive Review
The present knowledge on the androgens role in cardiovascular physiology is not fully completed. It remains unclear whether low serum testosterone concentrations in men are an independent risk factor for cardiovascular diseases (CVDs) or a marker of the presence of CVD. However, we demonstrated that endogenous testosterone levels may be implicated in CVDs. Androgens role in modulating cardiovascular function is one of the highest importances, given that its deficiency is strongly associated with hypertension, atherosclerosis, diabetes, obesity, and cardiac hypertrophy. Although significant and independent association between testosterone levels and cardiovascular events in elderly men have not been confirmed in large prospective studies, cross-sectional studies, however, suggested that low testosterone levels in elderly men are associated with CVDs. The results of androgen therapy are not also conclusive. Perhaps, the effects of testosterone treatment of cardiovascular mortality and morbidity have not been extensively examined in control studies. Data on male animal experimentation of the effect of testosterone replacement therapy are either neutral or beneficial on the development of atherosclerosis. Since circulatory androgen levels modulation is expected to cause many other side effects, it seems to be essential to develop a strategy to target androgen receptor for better treating the CVDs
Synthesis of amine functionalized graphite nanosheets and their water-soluble derivative for drug loading and controlled release
A facile route to synthesize amine (–NH2) functionalized graphite nanosheets (AFGNS) by 2-step controlled chemical modification of microcrystalline graphite is described. The method begins with nitration by mixed acid (HNO3 : H2SO4 in 1 : 1 v/v ratio), followed by reduction with Na2S to form AFGNS. The AFGNS was reacted with carboxylic acid-terminated polyethylene glycol (PEG) chains (MeO–mPEG–COOH, MW = 5000 Da) in the presence of a carbodiimide coupling agent to obtain a water-soluble PEGylated AFGNS (P-AFGNS) composite. Anticancer drug doxorubicin (DOX) was loaded on this composite with a loading capacity of 0.296 mg mg−1 for an initial concentration of 0.232 mg mL−1 DOX and 0.136 mg mL−1 of P-AFGNS and the release of DOX from this water-soluble DOX loaded P-AFGNS composite at two different temperatures was found to be strongly pH dependent
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Irreversible Hemichorea–Hemiballism in a Case of Nonketotic Hyperglycemia Presenting as the Initial Manifestation of Diabetes Mellitus
Background: Hemichorea–hemiballism (HCHB) is a hyperkinetic movement disorder with features of both chorea and ballism occurring on the same side.
Case report: We present a case of HCHB due to nonketotic hyperglycemia (NKH) that was the initial presentation of diabetes and was irreversible clinically even after 6 months of optimal blood sugar control.
Discussion: Although HCHB due to hyperglycemia is a potentially reversible condition in the majority of patients, prolonged uncontrolled hyperglycemia may cause ischemic insult and persistent symptoms. Hyperglycemia should always be kept in the list of differentials while dealing with patients who are newly diagnosed with HCHB
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