1,104 research outputs found
Lattice polarization effects on the screened Coulomb interaction of the GW approximation
In polar insulators where longitudinal and transverse optical phonon modes
differ substantially, the electron-phonon coupling affects the energy-band
structure primarily through the long-range Fr\"ohlich contribution to the Fan
term. This diagram has the same structure as the self-energy where
originates from the electron part of the screened coulomb interaction. The two
can be conveniently combined by combining electron and lattice contributions to
the polarizability. Both contributions are nonanalytic at the origin, and
diverge as so that the predominant contribution comes from a small
region around . Here we adopt a simple estimate for the Fr\"ohlich
contribution by assuming that the entire phonon part can be attributed to a
small volume of near . We estimate the magnitude for
from a generalized Lyddane-Sachs-Teller relation,
and the radius from the inverse of the polaron length scale. The gap correction
is shown to agree with Fr\"ohlich's simple estimate of
the polaron effect
Self-rated effects of reading, TV viewing and daily activities on dreaming in adolescents and adults: The UK library study.
The continuity hypothesis of dreaming states that our daily activities like reading books and watching films,
movies and shows should be represented in our dreams. The majority of participants in the UK library study (N = 1375)
stated that their dreams are affected by their reading and TV consumption, and by their daily activities. The more time
they spend with an activity, the more likely they reported an effect of this activity on dreaming. Future studies should use
daily logs and dream diaries to validate the present findings. In addition, measures of emotional intensity of the waking
life experience and attitude towards dreaming should be included as these factors might have an effect on the continuity
between waking and dreaming
Improved quasiparticle self-consistent electronic band structure and excitons in -LiGaO
The band structure of -LiGaO is calculated using the quasiparticle
self-consistent QS method where the screened Coulomb interaction is evaluated including electron-hole interaction ladder diagrams and is
the one-electron Green's function. Improved convergence compared to previous
calculations leads to a significantly larger band gap of about 7.0 eV. However,
exciton binding energies are found to be large and lead to an exciton gap of
about 6.0 eV if also a zero-point-motion correction of about eV is
included. These results are in excellent agreement with recent experimental
results on the onset of absorption. Besides the excitons observed thus far, the
calculations indicate the existence of a Rydberg-like series of exciton excited
states, which is however modified from the classical Wannier exciton model by
the anisotropies of the material and the more complex mixing of Bloch states in
the excitons resulting from the Bethe-Salpeter equation. The exciton fine
structure and the exciton wave functions are visualized and analyzed in various
ways
Optical response and band structure of LiCoO2 including electron-hole interaction effects
The optical response functions and band structures of LiCoO are studied
at different levels of approximation, from density functional theory (DFT) in
the generalized gradient approximation (GGA) to quasiparticle self-consistent
QS (with for Green's function and for screened Coulomb interaction)
without and with ladder diagrams (QS) and the Bethe Salpeter Equation
(BSE) approach. The QS method is found to strongly overestimate the band
gap and electron-hole or excitonic effects are found to be important. They
lower the quasiparticle gap by only about 11~\% but the lowest energy peaks in
absorption are found to be excitonic in nature. The contributions from
different band to band transitions and the relation of excitons to band-to-band
transitions are analyzed. The excitons are found to be strongly localized. A
comparison to experimental data is presented.Comment: 10 pages, 9 figure
Self-rated effects of reading, TV viewing and daily activities on dreaming in adolescents and adults: The UK library study.
The continuity hypothesis of dreaming states that our daily activities like reading books and watching films,
movies and shows should be represented in our dreams. The majority of participants in the UK library study (N = 1375)
stated that their dreams are affected by their reading and TV consumption, and by their daily activities. The more time
they spend with an activity, the more likely they reported an effect of this activity on dreaming. Future studies should use
daily logs and dream diaries to validate the present findings. In addition, measures of emotional intensity of the waking
life experience and attitude towards dreaming should be included as these factors might have an effect on the continuity
between waking and dreaming
Livestock ownership is associated with higher odds of anaemia among preschoolâaged children, but not women of reproductive age in Ghana
Livestock ownership may influence anaemia through complex and possibly contradictory mechanisms. In this study, we aimed to determine the association of household livestock ownership with anaemia among women aged 15â49Â years and children aged 6â59Â months in Ghana and to examine the contribution of animal source foods (ASFs) to consumption patterns as a potential mechanism mediating this association. We analysed data on 4,441 women and 2,735 children from the 2014 Ghana Demographic and Health Survey and 16,772 households from the Ghana Living Standards Survey Round 6. Haemoglobin measurements were used to define anaemia (nonâpregnant women: <120Â g/L; children: <110Â g/L). Childâ and householdâlevel ASF consumption data were collected from 24âhour food group intake and food consumption and expenditure surveys, respectively. In multiple logistic regression models, household livestock ownership was associated with anaemia among children (OR, 95% CI: 1.5 [1.1, 2.0]), but not women (1.0 [0.83, 1.2]). Household ownership of chickens was associated with higher odds of anaemia among children (1.6 [1.2, 2.2]), but ownership of other animal species was not associated with anaemia among women or children. In path analyses, we observed no evidence of mediation of the association of household livestock ownership with child anaemia by ASF consumption. Ownership of livestock likely has limited importance for consumption of ASFs among young children in Ghana and may in fact place children at an increased risk of anaemia. Further research is needed to elucidate if and how pathogen exposure associated with livestock rearing may underlie this increased risk of anaemia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144629/1/mcn12604_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144629/2/mcn12604.pd
An anti-siglec-8 antibody depletes sputum eosinophils from asthmatic subjects and inhibits lung mast cells
Background Sialic acid-binding immunoglobulin-like lectin (Siglec)-8 is expressed on mast cells and eosinophils, but information about Siglec-8 expression and function in the lung is limited. A humanized antibody, AK002, targeting Siglec-8 is undergoing development for treatment of diseases associated with mast cell and eosinophil-driven inflammation. Objective To characterize Siglec-8 expression in the airway in asthma and determine whether antibodies that target Siglec-8 (S8mAbs) can decrease airway eosinophils in asthma or inhibit lung mast cell activation. Methods Gene expression profiling and flow cytometry were used to characterize Siglec-8 expression in sputum cells from stable asthma. An antibody-dependent cellular cytotoxicity (ADCC) assay was used to determine whether an S8mAb can decrease eosinophils in sputum from asthma patients ex vivo. A mast cell activation assay was used to determine whether an S8mAb can inhibit mast cell activation in human lung tissue ex vivo. Results Gene expression for Siglec-8 is increased in sputum cells in asthma and correlates with gene expression for eosinophils and mast cells. Gene expression for Siglec-8 is inversely and significantly correlated with measures of airflow obstruction in asthma patients. Siglec-8 is prominently expressed on the surface of eosinophils and mast cells in sputum. S8mAbs decrease eosinophils in sputum from patients with asthma and inhibit Fc epsilon R1-activated mast cells in lung tissues. Conclusions and Clinical Relevance Siglec-8 is highly expressed on eosinophils and mast cells in asthmatic sputum and targeting Siglec-8 with an antibody is a plausible strategy to decrease sputum eosinophils and inhibit lung mast cells in asthma
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Carnauba wax nanoparticles enhance strong systemic and mucosal cellular and humoral immune responses to HIV-gp140 antigen
Induction of humoral responses to HIV at mucosal compartments without inflammation is important for vaccine design. We developed charged wax nanoparticles that efficiently adsorb protein antigens and are internalized by DC in the absence of inflammation. HIV-gp140-adsorbed nanoparticles induced stronger in vitro T-cell proliferation responses than antigen alone. Such responses were greatly enhanced when antigen was co-adsorbed with TLR ligands. Immunogenicity studies in mice showed that intradermal vaccination with HIV-gp140 antigen-adsorbed nanoparticles induced high levels of specific IgG. Importantly, intranasal immunization with HIV-gp140-adsorbed nanoparticles greatly enhanced serum and vaginal IgG and IgA responses. Our results show that HIV-gp140-carrying wax nanoparticles can induce strong cellular/humoral immune responses without inflammation and may be of potential use as effective mucosal adjuvants for HIV vaccine candidates
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