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DMFT Reveals the Non-Hermitian Topology and Fermi Arcs in Heavy-Fermion Systems.
When a strongly correlated system supports well-defined quasiparticles, it allows for an elegant one-body effective description within the non-Hermitian topological theory. While the microscopic many-body Hamiltonian of a closed system remains Hermitian, the one-body quasiparticle Hamiltonian is non-Hermitian due to the finite quasiparticle lifetime. We use such a non-Hermitian description in the heavy-fermion two-dimensional systems with the momentum-dependent hybridization to reveal a fascinating phenomenon which can be directly probed by the spectroscopic measurements, the bulk "Fermi arcs." Starting from a simple two-band model, we first combine the phenomenological approach with the perturbation theory to show the existence of the Fermi arcs and reveal their connection to the topological exceptional points, special points in the Brillouin zone where the Hamiltonian is nondiagonalizable. The appearance of such points necessarily requires that the electrons belonging to different orbitals have different lifetimes. This requirement is naturally satisfied in the heavy-fermion systems, where the itinerant c electrons experience much weaker interaction than the localized f electrons. We then utilize the dynamical mean field theory to numerically calculate the spectral function and confirm our findings. We show that the concept of the exceptional points in the non-Hermitian quasiparticle Hamiltonians is a powerful tool for predicting new phenomena in strongly correlated electron systems
Fat-free mass and calf circumference as body composition indices to determine non-exercise activity thermogenesis in patients with diabetes
13301甲第4345号博士(医学)金沢大学博士論文本文Full 以下に掲載:Journal of Diabetes Investigation 7(3) pp.352-358 2016. Asian Association for the Study of Diabetes and John Wiley & Sons Australia, Ltd. 共著者:Yuki Isobe, Masaru Sakurai, Yuki Kita, Yumie Takeshita, Hirofumi Misu, Shuichi Kaneko, Toshinari Takamur
High Time-Resolution Monitoring of Free-Tropospheric Sulfur Dioxide and Nitric Acid at the Summit of Mt. Fuji, Japan
This is the first paper that describes the atmospheric sulfur dioxide (SO2) and nitric acid (HNO3) monitored with a good time-resolution at the summit (3,776 m a.s.l.), which is located in the free troposphere, and southeastern foot (1,284 m a.s.l.) of Mt. Fuji. Japan. During the summer of 2012, two analytical systems consisting mainly of a parallel-plate wet denuder and ion chromatograph operated simultaneously at both the sampling sites. All the samples collected at both the sampling sites contained detectable levels of sulfate from gas-phase SO2 while the nitrate from gas-phase HNO3 was detectable in 97.8% of air samples at the southeastern foot and 88.4% at the summit. The average concentrations of SO2 and HNO3 were, respectively, 0.061 ± 0.071 and 0.031 ± 0.020 ppbv at the summit (n = 672), and 0.347 ± 0.425 and 0.146 ± 0.070 ppbv at the southeastern foot (n = 1344) of Mt. Fuji. Both the acidic gases at the southeastern foot and the HNO3 at the summit showed a diurnal pattern with daytime maxima and nighttime minima. Meanwhile, the SO2 at the summit did not show a distinct shift, which indicates the SO2 concentrations at the summit would be principally controlled by the advection of air parcel in the free troposphere
Fat-free mass and calf circumference as body composition indices to determine non-exercise activity thermogenesis in patients with diabetes
Aims/Introduction: To investigate the clinical and anthropometrical parameters that are associated with non-exercise activity thermogenesis that is composed of basal energy expenditure (BEE) and diet-induced thermogenesis (DIT) in patients with diabetes. Materials and Methods: Body composition was assessed using bioelectrical impedance, and BEE and DIT were measured using indirect calorimetry in 40 Japanese patients with diabetes. Results: BEE correlated positively with bodyweight, body mass index, fat mass, and fat-free mass, and correlated negatively with age in both men and women. In multivariate logistic regression analysis, BEE correlated positively with both fat mass and fat-free mass independently of sex and age. In addition, DIT correlated positively with bodyweight, body mass index, fat mass and fat-free mass, and correlated negatively with age in women, but not men. Fat-free mass contributed to DIT at least partly, and an aging-related decrease in DIT was observed. The best anthropometric parameter that reflected fat mass and fat-free mass was hip circumference (HC) and calf circumference (CC), respectively, in both men and women. Indeed, both HC (men β = 0.600, P < 0.001; women β = 0.752, P < 0.001) and CC (men β = 0.810, P = 0.012; women β = 0.821, P = 0.002) were correlated with BEE independently of age and sex. In addition, CC (β = 0.653, P = 0.009), but not HC was correlated with DIT significantly only in females, independently of age. Conclusions: HC reflects fat mass and was positively associated with BEE, but not with DIT. In contrast, CC reflects fat-free mass, and was positively associated with BEE in both men and women, and with DIT in women. © 2015 Asian Association for the Study of Diabetes and Wiley Publishing Asia Pty Ltd
Stellar and AGN Feedback Probed with Outflows in JWST Galaxies at z=3-9: Implications of Frequent Nearly-Spherical Galactic Fountains
We study outflows in 130 galaxies with -22<MUV<-16 at z=3-9 identified in
JWST NIRSpec and NIRCam WFSS data taken by the ERO, CEERS, FRESCO, GLASS, and
JADES programs. We identify 30 out of the 130 galaxies with broad components of
FWHM~200-700 km/s in the emission lines of H and [OIII] that trace
ionized outflows, and find no excesses from the star-formation main sequence.
Four out of the 30 outflowing galaxies are Type 1 AGN whose H
emission lines include line profile components as broad as FWHM>1000 km/s. With
the velocity shift and line widths of the outflow broad lines, we obtain
~80-500 km/s for the outflow velocities. We find that the outflow velocities as
a function of star-formation rate are comparable to or higher than those of
galaxies at z~1, accounting for the selection bias, while the outflow
velocities of AGN are large but not significantly different from the others.
Interestingly, these outflow velocities are typically not high enough to escape
from the galactic potentials, suggestive of fountain-type outflows, which are
concluded on the basis of thorough comparisons with recent JWST results. We
estimate mass loading factors to be 0.1-1 that are not particularly
large, but comparable with those of z~1 outflows. The large fraction of
galaxies with outflows (30% with high resolution data) provides constraints on
outflow parameters, suggesting a wide opening angle of >45 deg and a large
duty-cycle of >30%, which gives a picture of more frequent and spherical
outflows in high-z galaxies.Comment: 16 pages, 11 figures, submitted to the Astrophysical Journa
JWST Measurements of Neutral Hydrogen Fractions and Ionized Bubble Sizes at Obtained with Ly Damping Wing Absorptions in 26 Bright Continuum Galaxies
We present volume-averaged neutral hydrogen fractions x_{\rm \HI} and
ionized bubble radii measured with Ly damping wing
absorptions of galaxies at the epoch of reionization. We combine JWST/NIRSpec
spectra taken by CEERS, GO-1433, and DDT-2750 programs, and obtain 26 bright
UV-continuum galaxies at . We construct 4 composite spectra binned by
redshift, and find the clear evolution of spectral flattening towards high
redshift at the rest-frame \AA\ suggesting the increase of Ly
damping wing absorption. We estimate Ly damping wing absorption in the
composite spectra with realistic templates including Ly emission and
circum-galactic medium absorptions. Assuming the standard inside-out
reionization picture having an ionized bubble with around a galaxy
in the inter-galactic medium of x_{\rm \HI}, we obtain x_{\rm \HI} () values monotonically increasing (decreasing) from x_{\rm
\HI}={0.46}^{+0.36}_{-0.32} to ( to comoving Mpc)
at redshift to . The
redshift evolution of x_{\rm \HI} indicates moderately late reionization
history consistent with the one suggested from the electron scattering of
cosmic microwave background and the evolution of UV luminosity function with an
escape fraction . Our measurements are
about 20 times larger than the cosmic average values estimated by analytic
calculations for a given x_{\rm \HI}, while our measurements are
comparable with the values for merged ionized bubbles around bright galaxies
predicted by recent numerical simulations
Pure Spectroscopic Constraints on UV Luminosity Functions and Cosmic Star Formation History From 25 Galaxies at Confirmed with JWST/NIRSpec
We present pure spectroscopic constraints on the UV luminosity functions and
cosmic star formation rate (SFR) densities from 25 galaxies at
. By reducing the JWST/NIRSpec spectra taken in
multiple programs of ERO, ERS, GO, and DDT with our analysis technique, we
independently confirm 16 galaxies at including new
redshift determinations, and a bright interloper at that
was claimed as a photometric candidate at z~16. In conjunction with nine
galaxies at redshifts up to in the literature, we make
a sample of 25 spectroscopically-confirmed galaxies in total and carefully
derive the best estimates and lower limits of the UV luminosity functions.
These UV luminosity function constraints are consistent with the previous
photometric estimates within the uncertainties and indicate mild redshift
evolution towards z~12 showing tensions with some theoretical models of rapid
evolution. With these spectroscopic constraints, we obtain firm lower limits of
the cosmic SFR densities and spectroscopically confirm a high SFR density at
z~12 beyond the constant star-formation efficiency models, which supports
earlier claims from the photometric studies. While there are no
spectroscopically-confirmed galaxies with very large stellar masses violating
the CDM model due to the removal of the bright interloper, we confirm
star-forming galaxies at with stellar masses much
higher than model predictions. Our results indicate possibilities of high
star-formation efficiency (>5%), hidden AGN, top-heavy initial mass function
(possibly with Pop-III), and large scatter/variance. Having these successful
and unsuccessful spectroscopy results, we suggest observational strategies for
efficiently removing low redshift interlopers for future JWST programs.Comment: 27 pages, 18 figures, submitted to Ap
Formation of vv lacunary polyoxovanadates and interconversion reactions of dodecavanadate species
金沢大学理工研究域物質化学系Oxidation, reactions of the reduced decavanadate [VIV2Vv8O26]4- (1) with halide guest anions were investigated for the synthesis of Vv host molecules. The reaction with Cl- afforded a new dodecavanadate, [HVV12O32(C1)]4-(3), which incorporated the guest chloride anion. The polyoxovanadate framework of 3 is different from, the bowl-shaped dodecavanadate [VV12O 32(CH3CN)]4- (2). The structure of 3 is regarded as a trilacunary counterpart of the pentadecavanadate [V V9VIV8O36C1] 4-. Employment: of an F-template yielded the layered polyoxovanadate [HVV11O29F2] 4- (4). The framework of 4 is a monolacunary structure of the fluoride-incorporated dodecavanadate [H6VV2VIv10O30F2] 6-, in which one of the VO groups at the belt position is removed. The three vana-dium atoms in the capping units are connected, by (μ3-F bridges. Reaction with Br provided [HVv12O32(Br)]4- (5) with minor formation of [H3VV10O28]3- Interconversion reactions between 2, 3, and 4 proceeded as follows: the reaction of 2 with Cl- prompted, an isomerization reaction of the bowl-type framework, affording 3; the reaction of 3 with F- gave 4; the reaction of 4 with CH3CN reproduced acetonitrile-incorporated 2. Complexes 3 and 4 were characterized by X-ray analysis. Polyoxovanadates 3 and 4, with the highest oxidation cores, exhibited distinct signals in the 51V NMR spectra, corresponding to lacunary polyoxovanadate geometries. © Wiley-VCH Verlag GmbH & Co. KGaA
A Comprehensive Study on Galaxies at z~9-17 Found in the Early JWST Data: UV Luminosity Functions and Cosmic Star-Formation History at the Pre-Reionization Epoch
We conduct a comprehensive study on dropout galaxy candidates at
using the first 90 arcmin JWST/NIRCam images taken by the early release
observations (ERO) and early release science (ERS) programs. With the JWST
simulation images, we find that a number of foreground interlopers are selected
with a weak photo- determination (). We thus carefully
apply a secure photo- selection criterion () and
conventional color criteria with confirmations of the ERO NIRSpec spectroscopic
redshifts, and obtain a total of 25 dropout galaxies at , including
two candidates at and
. We perform thorough comparisons of dropout galaxies
found in our work with recent JWST studies, and conclude that our galaxy sample
is reliable enough for statistical analyses. We derive the UV luminosity
functions at , and confirm that our UV luminosity functions at
and agree with those determined by previous HST and JWST
studies. The cosmic star-formation rate density decreases from to
, and perhaps to , but the densities at are higher than
the constant star formation efficiency model. Interestingly, there are six
bright galaxy candidates at with whose stellar
masses are very high, . Because a majority () of
these galaxies shows no signatures of AGNs in their morphologies, the high
cosmic star-formation rate densities and the existence of these stellar massive
galaxies are explained by no suppression of star-formation by the UV background
radiation at the pre-reionization epoch or an efficient UV radiation production
by Population III-like star formation.Comment: 36 pages, 19 figures. Submitted to ApJS. Comments welcom
Sitagliptin versus mitiglinide switched from mealtime dosing of a rapid-acting insulin analog in patients with type 2 diabetes: a randomized, parallel-group study
Purpose We determined the feasibility of substituting sitagliptin or mitiglinide for bolus insulin injection therapy in patients with type 2 diabetes. Methods 60 patients with type 2 diabetes were enrolled and randomized to switch from mealtime dosing of a rapid-acting insulin analog to either sitagliptin or mitiglinide for 16 weeks. Results Body weight, body mass index, and waist circumference decreased significantly in both groups at the end of the study. Mitiglinide significantly increased fasting plasma glucose (FPG) levels at the end of the study from 146.5±36.3 to 168.0±38.8 mg/dL, whereas sitagliptin did not affect FPG. Glycated hemoglobin (HbA1c) and 1,5-anhydroglucitol increased significantly in both groups. The C peptide immunoreactivity (CPR) responses after arginine were diminished in both groups. γ-GTP and triglycerides increased, and high-density lipoprotein cholesterol and adiponectin decreased, in the sitagliptin group, but not in the mitiglinide group. Mean Diabetes Treatment Satisfaction Questionnaire scores improved significantly in both groups. Patients whose mean total daily doses of rapid-acting insulin analog were 16.6 and 17.8 units were switched to sitagliptin and mitiglinide, respectively, without a change in the HbA1c level. Total insulin doses/body weight predicted changes in HbA1c only in the sitagliptin group, but not in the mitiglinide group. Use of >0.27 IU/kg of a rapid-acting insulin analog predicted an increase in HbA1c after switching to sitagliptin. The CPR index (CPI) was also a predictor for a change in HbA1c in the sitagliptin group, but not in the mitiglinide group; patients with a CPI<1.4 developed a worse HbA1c after switching to sitagliptin. Conclusions Sitagliptin may predominantly act on FPG, whereas mitiglinide may act on postprandial plasma glucose to achieve glycemic control after switching from a bolus insulin regimen. Additional therapy to sitagliptin or mitiglinide is clearly required to obtain equivalent glycemic control in patients using a higher dose of insulin
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