400 research outputs found
Structural phase transitions and their influence on Cu+ mobility in superionic ferroelastic Cu6PS5I single crystals
The structural origin of Cu+ ions conductivity in Cu6PS5I single crystals is
described in terms of structural phase transitions studied by X-ray
diffraction, polarizing microscope and calorimetric measurements. Below the
phase transition at Tc=(144-169) K Cu6PS5I belongs to monoclinic, ferroelastic
phase, space group Cc. Above Tc crystal changes the symmetry to cubic
superstructure, space group F-43c (a=19.528); finally at 274K disordering of
the Cu+ ions increases the symmetry to F-43m, (a=9.794). The phase transition
at 274K coincides well with a strong anomaly in electrical conductivity
observed in the Arrhenius plot. Diffusion paths for Cu+ ions are evidenced by
means of the atomic displacement factors and split model. Influence of the
copper stechiometry on the Tc is also discussed.Comment: conference pape
Guanfacine treatment improves ADHD phenotypes of impulsivity and hyperactivity in a neurofibromatosis type 1 mouse model
BACKGROUND:
Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with a mutation in one copy of the neurofibromin gene (NF1+/-). Even though approximately 40-60% of children with NF1 meet the criteria for attention deficit hyperactivity disorder (ADHD), very few preclinical studies, if any, have investigated alterations in impulsivity and risk-taking behavior. Mice with deletion of a single NF1 gene (Nf1+/-) recapitulate many of the phenotypes of NF1 patients.
METHODS:
We compared wild-type (WT) and Nf1+/- mouse strains to investigate differences in impulsivity and hyperactivity using the delay discounting task (DDT), cliff avoidance reaction (CAR) test, and open field. We also investigated whether treatment with the clinically effective alpha-2A adrenergic receptor agonist, guanfacine (0.3 mg/kg, i.p.), would reverse deficits observed in behavioral inhibition.
RESULTS:
Nf1+/- mice chose a higher percentage of smaller rewards when both 10- and 20-s delays were administered compared to WT mice, suggesting Nf1+/- mice are more impulsive. When treated with guanfacine (0.3 mg/kg, i.p.), Nf1+/- mice exhibited decreased impulsive choice by waiting for the larger, delayed reward. Nf1+/- mice also exhibited deficits in behavioral inhibition compared to WT mice in the CAR test by repetitively entering the outer edge of the platform where they risk falling. Treatment with guanfacine ameliorated these deficits. In addition, Nf1+/- mice exhibited hyperactivity as increased distance was traveled compared to WT controls in the open field. This hyperactivity in Nf1+/- mice was reduced with guanfacine pre-treatment.
CONCLUSIONS:
Overall, our study confirms that Nf1+/- mice exhibit deficits in behavioral inhibition in multiple contexts, a key feature of ADHD, and can be used as a model system to identify alterations in neural circuitry associated with symptoms of ADHD in children with NF1
Optimization of an Alkylpolyglucoside-Based Dishwashing Detergent Formulation.
The aim of this work was to formulate and optimize the washing performance of an alkylpolyglucoside-based dishwashing detergent. The liquid detergent was formulated with five ingredients of commercial origin: anionic (linear sodium alkylbenzenesulfonate and sodium laurylethersulfate), nonionic (C12–C14 alkylpolyglucoside) and zwitterionic (a fatty acid amide derivative with a betaine structure) surfactants, and NaCl for viscosity control. In addition to the plate test, other properties were investigated including ‘‘cloud point’’, viscosity, and emulsion stability. Statistical analysis software was used to generate a central composite experimental design. Then, a second order design and analysis of experiments approach, known as the Response Surface Methodology, was set up to investigate the effects of the five components of the formulation on the studied properties in the region covering plausible component ranges. The method proved to be efficient for locating the domains of concentrations where the desired properties were met
Changes in Clinical Context for Kaposi's Sarcoma and Non-Hodgkin Lymphoma Among People With HIV Infection in the United States
The biology of HIV-associated cancers may differ depending on immunologic and virologic context during development. Therefore, an understanding of the burden of Kaposi's sarcoma (KS) and non-Hodgkin lymphoma (NHL) relative to antiretroviral therapy (ART), virologic suppression, and CD4 count is important
The Universal One-Loop Effective Action
We present the universal one-loop effective action for all operators of
dimension up to six obtained by integrating out massive, non-degenerate
multiplets. Our general expression may be applied to loops of heavy fermions or
bosons, and has been checked against partial results available in the
literature. The broad applicability of this approach simplifies one-loop
matching from an ultraviolet model to a lower-energy effective field theory
(EFT), a procedure which is now reduced to the evaluation of a combination of
matrices in our universal expression, without any loop integrals to evaluate.
We illustrate the relationship of our results to the Standard Model (SM) EFT,
using as an example the supersymmetric stop and sbottom squark Lagrangian and
extracting from our universal expression the Wilson coefficients of
dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version
accepted for publication in JHE
Multi-Scalar-Singlet Extension of the Standard Model - the Case for Dark Matter and an Invisible Higgs Boson
We consider a simple extension of the Standard Model by the addition of N
real scalar gauge singlets \vp that are candidates for Dark Matter. By
collecting theoretical and experimental constraints we determine the space of
allowed parameters of the model. The possibility of ameliorating the little
hierarchy problem within the multi-singlet model is discussed. The
Spergel-Steinhardt solution of the Dark Matter density cusp problem is
revisited. It is shown that fitting the recent CRESST-II data for Dark Matter
nucleus scattering implies that the standard Higgs boson decays predominantly
into pairs of Dark Matter scalars. It that case discovery of the Higgs boson at
LHC and Tevatron is impossible. The most likely mass of the dark scalars is in
the range 15 GeV \lsim \mvp \lsim 50 GeV with BR(h \to \vp\vp) up to 96%.Comment: 18 pages, 15 figure
Ten-year Survival by Race/Ethnicity and Sex Among Treated, HIV-infected Adults in the United States
BackgroundEnsuring equal access to antiretroviral therapy (henceforth therapy) should alleviate disparities in health outcomes among persons infected with human immunodeficiency virus (HIV). However, evidence supporting the persistence of disparities in survival following therapy initiation is mixed.MethodsPatients initiating therapy in eight academic medical centers in the Centers for AIDS Research Network of Integrated Clinical Systems between 1 January 1998 and 30 December 2011. Patients (n = 10 017) were followed from therapy initiation until death from any cause, administrative censoring at 10 years after therapy initiation or the end of follow-up on 31 December 2011. The 10-year risk of all-cause mortality was calculated from standardized Kaplan-Meier survival curves.ResultsPatients were followed for a median of 4.7 years (interquartile range: 2.2, 8.2). During 51 121 person-years of follow-up, 1224 of the 10 017 patients died. The overall 10-year mortality risk was 20.2% (95% confidence interval [CI], 19.2%, 21.3%). Black men and women experienced standardized 10-year all-cause mortality risks that were 7.2% (95% CI, 4.3%, 10.1%) and 7.9% (95% CI, 3.9%, 12.0%) larger (absolute difference) than white men. White women, Hispanic men, and Hispanic women all had lower 10-year mortality than white men.ConclusionsThese data serve as a call to action to identify modifiable mechanisms leading to these observed mortality disparities among HIV-infected black patients. Effective interventions are needed to ensure that the goal of the National HIV/AIDS Strategy to overcome health disparities becomes a reality
Constraining parameter space in type-II two-Higgs doublet model in light of a 126 GeV Higgs boson
We explore the implications of a 126 GeV Higgs boson indicated by the recent
LHC results for two-Higgs doublet model (2HDM). Identifying the 126 GeV Higgs
boson as either the lighter or heavier of CP even neutral Higgs bosons in 2HDM,
we examine how the masses of Higgs fields and mixing parameters can be
constrained by the theoretical conditions and experimental constraints. The
theoretical conditions taken into account are the vacuum stability,
perturbativity and unitarity required to be satisfied up to a cut-off scale. We
also show how bounds on the masses of Higgs bosons and mixing parameters depend
on the cut-off scale. In addition, we investigate whether the allowed regions
of parameter space can accommodate particularly the enhanced di-photon signals,
ZZ* and WW* decay modes of the Higgs boson, and examine the prediction of the
signal strength of Z{\gamma} decay mode for the allowed regions of the
parameter space.Comment: To be published in JHEP, 20 pages, 11 figures, Figures and results
are updated for the recent LHC result
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