5,134 research outputs found
The magnetic structure of the chain family NaCaVO determined by muon-spin rotation
We present muon-spin rotation measurements on polycrystalline samples of the
complete family of the antiferromagnetic (AF) chain compounds,
NaCaVO. In this family, we explore the magnetic properties
from the metallic NaVO to the insulating CaVO. We find a
critical which separates the low and high Na-concentration
dependent transition temperature and its magnetic ground state. In the
compounds, the magnetic ordered phase is characterized by a single homogenous
phase and the formation of incommensurate spin-density-wave order. Whereas in
the compounds, multiple sub-phases appear with temperature and .
Based on the muon data obtained in zero external magnetic field, a careful
dipolar field simulation was able to reproduce the muon behavior and indicates
a modulated helical incommensurate spin structure of the metallic AF phase. The
incommensurate modulation period obtained by the simulation agrees with that
determined by neutron diffraction.Comment: 7 pages, 7 figures, accepted for publication in PR
The magnetic phase of the perovskite CaCrO studied with SR
We investigated the magnetic phase of the perovskite CaCrO by using the
muon spin relaxation technique accompanied by susceptibility measurements. A
thermal hysteresis loop is identified with a width of about 1 K at the
transition temperature. Within the time scale of the muon lifetime, a static
antiferromagnetic order is revealed with distinct multiple internal fields
which are experienced in the muon interstitial sites below the phase-transition
temperature, . Above , lattice deformations are indicated by
transverse-field muon-spin rotation and relaxation suggesting a magneto-elastic
mechanism.Comment: 5 pages, 4 figures. Accepted for publication in PR
Shamans and nativism:postcolonial trauma in Spirits’ Homecoming (2016) and Manshin: Ten Thousand Spirits (2013)
Comparing bladder neck contracture rate between robotic intracorporeal and extracorporeal neobladder construction
Robot-assisted radical cystectomy (RARC) has become more accessible to surgeons worldwide, and descriptions of intracorporeal urinary diversion techniques, such as orthotopic neobladder construction, have increased. In this study, we aim to compare the rate of bladder neck contracture (BNC) formation between RARC and two different urinary diversion techniques. We retrospectively reviewed our institutional database for patients with bladder cancer who underwent RARC with intracorporeal neobladder (ICNB) construction (n = 11) or extracorporeal neobladder (ECNB) construction (n = 11) between 2012 and 2020. BNC was defined by the need for an additional surgical procedure (e.g., dilatation, urethrotomy). Patients who underwent RARC with ICNB (n = 11) were compared to patients who underwent RARC with ECNB (n = 11) across patient characteristics and postoperative BNC formation rates. Kaplan-Meier curves were generated for freedom from BNC based on the neobladder approach and compared with the log-rank test. For patients who received an ECNB, 73% (8/11) developed a BNC; in comparison, none of the patients in the ICNB group experienced a BNC. Kaplan-Meier survival analysis demonstrates the ECNB group\u27s median probability of freedom from BNC as 1.3 years, while the ICNB group was free of BNC over the study period (p \u3c 0.001). RARC with ICNB creation demonstrated a significantly reduced BNC rate in contrast to RARC with ECNB construction. Longer-term follow-up is needed to assess the durability of this difference in BNC rates
Revival-collapse phenomenon in the fluctuations of quadrature field components of the multiphoton Jaynes-Cummings model
In this paper we consider a system consisting of a two-level atom, initially
prepared in a coherent superposition of upper and lower levels, interacting
with a radiation field prepared in generalized quantum states in the framework
of multiphoton Jaynes-Cummings model. For this system we show that there is a
class of states for which the fluctuation factors can exhibit revival-collapse
phenomenon (RCP) similar to that exhibited in the corresponding atomic
inversion. This is shown not only for normal fluctuations but also for
amplitude-squared fluctuations. Furthermore, apart from this class of states we
generally demonstrate that the fluctuation factors associated with three-photon
transition can provide RCP similar to that occurring in the atomic inversion of
the one-photon transition. These are novel results and their consequence is
that RCP occurred in the atomic inversion can be measured via a homodyne
detector. Furthermore, we discuss the influence of the atomic relative phases
on such phenomenon.Comment: 17 pages, 4 figure
Ionic and electronic properties of the topological insulator BiTeSe investigated using -detected nuclear magnetic relaxation and resonance of Li
We report measurements on the high temperature ionic and low temperature
electronic properties of the 3D topological insulator BiTeSe using
ion-implanted Li -detected nuclear magnetic relaxation and
resonance. With implantation energies in the range 5-28 keV, the probes
penetrate beyond the expected range of the topological surface state, but are
still within 250 nm of the surface. At temperatures above ~150 K, spin-lattice
relaxation measurements reveal isolated Li diffusion with an
activation energy eV and attempt frequency s for atomic site-to-site hopping. At lower
temperature, we find a linear Korringa-like relaxation mechanism with a field
dependent slope and intercept, which is accompanied by an anomalous field
dependence to the resonance shift. We suggest that these may be related to a
strong contribution from orbital currents or the magnetic freezeout of charge
carriers in this heavily compensated semiconductor, but that conventional
theories are unable to account for the extent of the field dependence.
Conventional NMR of the stable host nuclei may help elucidate their origin.Comment: 17 pages, 12 figures, submitted to Phys. Rev.
Degenerate Rotating Black Holes, Chiral CFTs and Fermi Surfaces I - Analytic Results for Quasinormal Modes
In this work we discuss charged rotating black holes in
that degenerate to extremal black holes with zero entropy. These black holes
have scaling properties between charge and angular momentum similar to those of
Fermi surface operators in a subsector of SYM. We add a
massless uncharged scalar to the five dimensional supergravity theory, such
that it still forms a consistent truncation of the type IIB ten dimensional
supergravity and analyze its quasinormal modes. Separating the equation of
motion to a radial and angular part, we proceed to solve the radial equation
using the asymptotic matching expansion method applied to a Heun equation with
two nearby singularities. We use the continued fraction method for the angular
Heun equation and obtain numerical results for the quasinormal modes. In the
case of the supersymmetric black hole we present some analytic results for the
decay rates of the scalar perturbations. The spectrum of quasinormal modes
obtained is similar to that of a chiral 1+1 CFT, which is consistent with the
conjectured field-theoretic dual. In addition, some of the modes can be found
analytically.Comment: 41 pages, 1 figure, LaTeX; v2: typos corrected, references adde
Prognostic parameters for recurrence of papillary thyroid microcarcinoma
<p>Abstract</p> <p>Background</p> <p>Papillary thyroid microcarcinoma (PTMC) is defined as a papillary thyroid carcinoma less than or equal to 1.0 cm in size. Independent prognostic factors for clinical recurrence of PTMC have not been clearly delineated.</p> <p>Methods</p> <p>Clinicopathological parameters predicting PTMC recurrence were determined by retrospective analysis of 307 patients.</p> <p>Results</p> <p>Of the 293 patients eligible for analysis, 14 (5%) had recurrence during a median follow-up time of 65 months. Recurrence was observed in 8 of 166 patients (0.5%) treated with total or near-total thyroidectomy; gender (P = 0.02) and presence of lateral cervical node metastases at initial surgery (P = 0.01) were associated with recurrence. Six of the 127 patients (0.5%) treated with hemi- or subtotal thyroidectomy experience recurrences, but no significant prognostic factor for recurrence was identified. Multivariate Cox-regression analysis showed that gender and cervical lymph node metastasis were significant variables</p> <p>Conclusion</p> <p>PTMC showed very diverse disease extent and could not be regarded as indolent, relatively benign disease based on the primary tumor size. The extent of surgery should be based on prognostic parameters, such as gender and lateral neck node metastasis, in patients with PTMC.</p
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