435 research outputs found
Orbital ordering in LaSrMnO studied by model Hartree-Fock calculation
We have investigated orbital ordering in the half-doped manganite
LaSrMnO, which displays spin, charge and orbital ordering,
by means of unrestricted Hartree-Fock calculations on the multiband -
model. From recent experiment, it has become clear that
LaSrMnO exhibits a cross-type orbital
ordering rather than the widely believed rod-type orbital
ordering. The calculation reveals that cross-type orbital
ordering results from an effect of in-plane distortion as well as from the
relatively long out-of-plane Mn-O distance. For the "Mn" site, it is
shown that the elongation along the c-axis of the MnO octahedra leads to an
anisotropic charge distribution rather than the isotropic one.Comment: 4 pages, 5 figure
Linear Responses in Time-dependent Hartree-Fock-Bogoliubov Method with Gogny Interaction
A numerical method to integrate the time-dependent Hartree-Fock Bogoliubov
(TDHFB) equations with Gogny interaction is proposed. The feasibility of the
TDHFB code is illustrated by the conservation of the energy, particle numbers,
and center-of-mass in the small amplitude vibrations of oxygen 20. The TDHFB
code is applied to the isoscalar quadrupole and/or isovector dipole vibrations
in the linear (small amplitude) region in oxygen isotopes (masses A = 18,20,22
and 24), titanium isotopes (A = 44,50,52 and 54), neon isotope (A = 26), and
magnesium isotopes (A = 24 and 34). The isoscalar quadrupole and isovector
dipole strength functions are calculated from the expectation values of the
isoscalar quadrupole and isovector dipole moments.Comment: 10 pages, 13 figure
Indirect Effects of Wnt3a/β-Catenin Signalling Support Mouse Spermatogonial Stem Cells In Vitro
Proper regulation of spermatogonial stem cells (SSCs) is crucial for sustaining steady-state spermatogenesis. Previous work has identified several paracrine factors involved in this regulation, in particular, glial cell line-derived neurotrophic factor and fibroblast growth factor 2, which promote long-term SSC self-renewal. Using a SSC culture system, we have recently reported that Wnt5a promotes SSC self-renewal through a β-catenin-independent Wnt mechanism whereas the β-catenin-dependent Wnt pathway is not active in SSCs. In contrast, another study has reported that Wnt3a promotes SSC self-renewal through the β-catenin-dependent pathway, as it can stimulate the proliferation of a spermatogonia cell line. To reconcile these two contradictory reports, we assessed Wnt3a effects on SSCs and progenitor cells, rather than a cell line, in vitro. We observed that Wnt3a induced β-catenin-dependent signalling in a large subset of germ cells and increased SSC numbers. However, further investigation revealed that cell populations with greater β-catenin-signalling activity contained fewer SSCs. The increased maintenance of SSCs by Wnt3a coincided with more active cell cycling and the formation of germ cell aggregates, or communities, under feeder-free conditions. Therefore, the results of this study suggest that Wnt3a selectively stimulates proliferation of progenitors that are committed to differentiation or are in the process of exiting the SSC state, leading to enhanced formation of germ cell communities, which indirectly support SSCs and act as an in vitro niche
Representation of Neck Velocity and Neck–Vestibular Interactions in Pursuit Neurons in the Simian Frontal Eye Fields
The smooth pursuit system must interact with the vestibular system to maintain the accuracy of eye movements in space (i.e., gaze-movement) during head movement. Normally, the head moves on the stationary trunk. Vestibular signals cannot distinguish whether the head or whole body is moving. Neck proprioceptive inputs provide information about head movements relative to the trunk. Previous studies have shown that the majority of pursuit neurons in the frontal eye fields (FEF) carry visual information about target velocity, vestibular information about whole-body movements, and signal eye- or gaze-velocity. However, it is unknown whether FEF neurons carry neck proprioceptive signals. By passive trunk-on-head rotation, we tested neck inputs to FEF pursuit neurons in 2 monkeys. The majority of FEF pursuit neurons tested that had horizontal preferred directions (87%) responded to horizontal trunk-on-head rotation. The modulation consisted predominantly of velocity components. Discharge modulation during pursuit and trunk-on-head rotation added linearly. During passive head-on-trunk rotation, modulation to vestibular and neck inputs also added linearly in most neurons, although in half of gaze-velocity neurons neck responses were strongly influenced by the context of neck rotation. Our results suggest that neck inputs could contribute to representing eye- and gaze-velocity FEF signals in trunk coordinates
Electronic Structure of Noncentrosymmetric Superconductor Li(PdPt3)B Studied by Photoemission Spectroscopy
We have performed x-ray photoemission spectroscopy on the system of
noncentrosymmetric superconductor, Li(PdPt3)B. For
LiPtB, we found 2 major peaks with 2 other weak components, and the
band calculations were in agreement with the observation. The assignment of
valence band features using the calculated partial density of states determined
that Pt 5d and B 2p contribute to the density of states at the Fermi level. The
effect of antisymmetric spin-orbit coupling on the band structure might have
been probed, and the analysis on the effect of Pt incorporation into the system
indicates the smooth evolution of electronic structures. We presented the
measurements of core levels (Pd 3d, Pt 4f, and B 1s) and discussed the chemical
bonding states and electronic structures from them.Comment: 14 pages, 5 figure
Children’s coping with in vivo peer rejection: An experimental investigation
We examined children's behavioral coping in response to an in vivo peer rejection manipulation. Participants (N=186) ranging between 10 and 13 years of age, played a computer game based on the television show Survivor and were randomized to either peer rejection (i.e., being voted out of the game) or non-rejection control. During a five-min. post-feedback waiting period children's use of several behavioral coping strategies was assessed. Rejection elicited a marked shift toward more negative affect, but higher levels of perceived social competence attenuated the negative mood shift. Children higher in depressive symptoms were more likely to engage in passive and avoidant coping behavior. Types of coping were largely unaffected by gender and perceived social competence. Implications are discussed. © 2006 Springer Science+Business Media, LLC
A Practical, One-Pot Synthesis of Highly Substituted Thiophenes and Benzo[b]thiophenes from Bromoenynes and o-Alkynylbromobenzenes
An efficient synthesis of thiophenes and benzo[b]thiophenes has been developed from easily available bromoenynes and o-alkynylbromobenzene derivatives. This novel one-pot procedure involves a Pd-catalyzed C–S bond formation using a hydrogen sulfide surrogate followed by a heterocyclization reaction. Moreover, in situ functionalization with selected electrophiles further expands the potential of this methodology to the preparation of the corresponding highly substituted sulfur heterocycles.Junta de Castilla y Leon (BU021A09 and GR-172) and Ministerio de Ciencia e Innovacion (MICINN) and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) for financial support. P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsJunta de Castilla y Leon (BU021A09 and GR-172) and Ministerio de Ciencia e Innovacion (MICINN) and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) for financial support. P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in
Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher
Recommended core outcome instruments for health‐related quality of life, long‐term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting
BackgroundThe Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema (AE) clinical trials. Previous consensus meetings have agreed on preferred instruments for clinician‐reported signs (Eczema Area and Severity Index, EASI) and patient‐reported symptoms (Patient‐Oriented Eczema Measure, POEM). This paper reports consensus decisions from the HOME VII meeting.ObjectivesTo complete the core outcome set for AE by agreeing on core outcome instruments for the domains of quality of life (QoL), long‐term control and itch intensity.MethodsA face‐to‐face consensus meeting was held in Tokyo, Japan (8–10 April 2019) including 75 participants (49 healthcare professionals/methodologists, 14 patients, 12 industry representatives) from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using predefined consensus rules.ResultsIt was agreed by consensus that QoL should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children’s Dermatology Life Quality Index (CDLQI) for children and the Infant’s Dermatology Quality of Life Index (IDQoL) for infants. For long‐term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long‐term control. The peak itch numerical rating scale (NRS)‐11 past 24 h was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum.ConclusionsFor now, the core outcome set for clinical trials in AE is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments
CD24 Expression is an Independent Prognostic Marker in Cholangiocarcinoma
CD24 has been described as an adverse prognostic marker in several malignancies. This study evaluates CD24 expression in cholangiocarcinoma and correlates the findings with clinicopathologic data and patient survival. Between 1996 and 2002, 22 consecutive patients with cholangiocarcinoma were treated at our institution. Demographic data, SEER stage, pathologic data, treatment, expression of CD24, mitogen-activated protein kinase (MAPK), phosphorylated MAPK, and survival were analyzed. The majority of the tumors demonstrated CD24 (81.8%) and p-MAPK (87%) expression. A negative association was noted between the expression of CD24 and p-MAPK. Median survival for patients with low expression of CD24 was 36 months and high expression was 8 months. Median survival for patients who received chemotherapy with low CD24 expression was 163 months, and for seven patients with high CD24 expression, it was 17 months (p = 0.04). With the addition of radiation therapy, median survival for patients with low expression of CD24 was 52 months and high expression was 17 months (p = 0.08). On multivariate analysis, the use of chemotherapy (p = 0.0014, hazard ratio 0.069) and the CD24 overexpression (p = 0.02, hazard ratio 7.528) were predictive of survival. CD24 is commonly expressed in cholangiocarcinoma, and overexpression is predictive of poor survival and possibly of lack of response to chemotherapy and radiation therapy. These findings may improve selection of patients for the appropriate treatment modality and the development of CD24-targeted therapy
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