211 research outputs found
Electronic signature of the vacancy ordering in NbO (Nb3O3)
We investigated the electronic structure of the vacancy-ordered 4d-transition
metal monoxide NbO (Nb3O3) using angle-integrated soft- and hard-x-ray
photoelectron spectroscopy as well as ultra-violet angle-resolved photoelectron
spectroscopy. We found that density-functional-based band structure
calculations can describe the spectral features accurately provided that
self-interaction effects are taken into account. In the angle-resolved spectra
we were able to identify the so-called vacancy band that characterizes the
ordering of the vacancies. This together with the band structure results
indicates the important role of the very large inter-Nb-4d hybridization for
the formation of the ordered vacancies and the high thermal stability of the
ordered structure of niobium monoxide
Reliability, validity, and responsiveness of the Japanese version of the Neck Pain and Disability Scale
Abstract Background Until recently, no Japanese versions have existed of the more popular, patient-reported disability questionnaires for neck pain. This study aimed to test the reliability, validity, and responsiveness of the Japanese version of the Neck Pain and Disability Scale (NPDS), one of the most widely used questionnaires in patients with neck pain. Methods In this validation study, 167 outpatients with neck pain participated. Patients received the NPDS and the Medical Outcome Study Short Form 36-item Health Survey (SF-36), and used Visual Analog Scales (VASs) to assess pain and global health. To examine test-retest reliability, patients who were considered stable by clinicians were given the NPDS 2 weeks after baseline. To examine responsiveness, patients who had not undergone treatment at the time of the first data collection or had no change in treatment over 3 months were studied again 2 weeks after starting a new medication or physical therapy. Results Of the 167 participants, 143 completed the questionnaires (85.6%). Factor analysis showed two factors, defined as neck-pain-related disability (factor 1) and neck-related pain (factor 2). Cronbach's a coefficient for factor 1, factor 2, and total score was 0.94, 0.93, and 0.96. The intra-class correlation coefficients for the 19 more stable patients were 0.79, 0.88, and 0.87. For concurrent validity, the correlation between NPDS subscales and total score and SF-36 subscale scores ranged from r = -0.54 to -0.22 (p \ 0.01). Correlations between the NPDS subscales and total score and VAS of pain ranged from 0.56 to 0.77 (p \ 0.01) and those for VAS of global health ranged from 0.48 to 0.63 (p \ 0.01). The NPDS subscales and total scores of the 41 patients retested after treatment were significantly improved. Electronic supplementary material The online version of this articl
Spectroscopic evidence of Kondo-induced quasi-quartet in CeRhAs
CeRhAs is a new multiphase superconductor with strong suggestions for
an additional itinerant multipolar ordered phase. The modeling of the low
temperature properties of this heavy fermion compound requires a quartet
Ce crystal-field ground state. Here we provide the evidence for the
formation of such a quartet state using x-ray spectroscopy. Core-level
photoelectron and x-ray absorption spectroscopy confirm the presence of Kondo
hybridization in CeRhAs. The temperature dependence of the linear
dichroism unambiguously reveils the impact of Kondo physics for coupling the
Kramer's doublets into an effective quasi-quartet. Non-resonant inelastic x-ray
scattering data find that the state with its lobes along
the 110 direction of the tetragonal structure ( orientation) contributes
most to the multi-orbital ground state of CeRhAs.Comment: 8 pages, 7 figure
Effects of TGF-β1 and IGF-1 on proliferation of human nucleus pulposus cells in medium with different serum concentrations
BACKGROUND: The low proliferative viability of human nucleus pulposus(NP) cells is considered as a cause of intervertebral discs degeneration. Growth factors, such as TGF-β1 and IGF-1, have been implicated in cell proliferation and matrix synthesis. OBJECTIVE: To investigate the dose-response and time-course effect of transforming growth factorβ1(TGF-β1) and insulin-like growth factor-1(IGF-1) on proliferation of NP cells. STUDY DESIGN: 3-(4,5-dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide (MTT) is reduced by dehydrogenase in mitochondria of live cells. The proliferative viability of cells corresponds to the amount of MTT reduced, which is measured with an enzyme-linked immunosorbent assay plate reader. In this study, we assessed dose- and time-dependent effects of NP cells to TGF-β1 and IGF-1 in medium with different serum concentrations by MTT assay. METHODS: After release of informed consent, tissue samples of NP were obtained from anterior surgical procedures performed on five donors with idiopathic scoliosis. Isolated cells were cultured in F12 medium supplemented with 10% fetal bovine serum(FBS). Cells were seeded in 96-well plates at 1 × 10(3 )cells/well. After synchronization, medium was replaced by F12 containing 1% or 10% FBS with either single or combination of TGF-β1 and IGF-1. Dose-response and time-course effect were examined by MTT assay. RESULTS: In the presence of 1% FBS, the response to IGF-1 was less striking, whereas TGF-β1 had a remarkably stimulating effect on cell proliferation. In 10% FBS, both of the two growth factors had statistical significant mitogenic effects, especially TGF-β1. The dose-dependent effect of TGF and IGF on cell proliferation was found within different concentrations of each growth factor(TGF-β1 1–10 μg/L, IGF-1 10–100 μg/L). The time-course effect showed a significant elevation three days later. CONCLUSION: TGF-β1 and IGF-1 were efficient to stimulate cell proliferation of human NP cells in vitro with a dose- and time-dependent manner. These results support the therapeutic potentials of the two growth factors in the treatment of disc degeneration
Liposomes as a model for the biological membrane : studies on daunorubicin bilayer interaction
In this study the interaction of the antitumoral drug daunorubicin with egg phosphatidylcholine (EPC) liposomes, used as a cell membrane model, was quantified by determination of the partition coefficient (Kp). The liposome/aqueous-phase Kp of daunorubicin was determined by derivative spectrophotometry and measurement of the zeta-potential. Mathematical models were used to fit the experimental data, enabling determination of Kp. In the partition of daunorubicin within the membrane both superficial electrostatic and inner hydrophobic interactions seem to be involved. The results are affected by the two types of interaction since spectrophotometry measures mainly hydrophobic interactions, while zeta-potential is affected by both interpenetration of amphiphilic charged molecules in the bilayer and superficial electrostatic interaction. Moreover, the degree of the partition of daunorubicin with the membrane changes with the drug concentration, due mainly to saturation factors. Derivative spectrophotometry and zeta-potential variation results, together with the broad range of concentrations studied, revealed the different types of interactions involved. The mathematical formalism applied also allowed quantification of the number of lipid molecules associated with one drug molecule
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Charge-transfer energy in iridates: A hard x-ray photoelectron spectroscopy study
We have investigated the electronic structure of iridates in the double perovskite crystal structure containing either Ir4+ or Ir5+ using hard x-ray photoelectron spectroscopy. The experimental valence band spectra can be well reproduced using tight-binding calculations including only the Ir 5d, O 2p, and O 2s orbitals with parameters based on the downfolding of the density-functional band structure results. We found that, regardless of the A and B cations, the A2BIrO6 iridates have essentially zero O 2p to Ir 5d charge-transfer energies. Hence double perovskite iridates turn out to be extremely covalent systems with the consequence being that the magnetic exchange interactions become very long ranged, thereby hampering the materialization of the long-sought Kitaev physics. Nevertheless, it still would be possible to realize a spin-liquid system using the iridates with a proper tuning of the various competing exchange interactions
Social entrepreneurship: problems and ways of their solution
For modern constantly developing societies, it is normal to create categories in the process of the activity of the participants of socio-economic processes themselves. Practice is theoretical, and theory is pragmatic, because it creates those concepts in which «practice» exists and develops. Such a category is "social entrepreneurship", which is "umbrella" for a number of socio-economic phenomena. The general term for social entrepreneurship includes those types of entrepreneurial activity that contradict the traditional notion of entrepreneurship as an activity of independent economic entities aimed at maximizing their profits. The development of social entrepreneurship is an indicator of the quality of the business climate in the region and requires a set of measures to ensure the mechanism and access of non-governmental organizations to the provision of services in the social sphere, the provision of state support to socially-oriented non-profit organizations, and the promotion of the development of PPP practices in the social sphere
DUX4 is a multifunctional factor priming human embryonic genome activation
Double homeobox 4 (DUX4) is expressed at the early pre-implantation stage in human embryos. Here we show that induced human DUX4 expression substantially alters the chromatin accessibility of non-coding DNA and activates thousands of newly identified transcribed enhance-like regions, preferentially located within ERVL-MaLR repeat elements. CRISPR activation of transcribed enhancers by C-terminal DUX4 motifs results in the increased expression of target embryonic genome activation (EGA) genes ZSCAN4 and KHDC1P1. We show that DUX4 is markedly enriched in human zygotes, followed by intense nuclear DUX4 localization preceding and coinciding Kith minor EGA. DUX4 knockdown in human zygotes led to changes in the EGA transcriptome but did not terminate the embryos. We also show that the DUX4 protein interacts with the Mediator complex via the C-terminal KIX binding motif. Our findings contribute to the understanding of DUX4 as a regulator of the non-coding genome.Peer reviewe
CaCu3Ru4O12: a high-kondo-temperature transition-metal oxide
遷移金属酸化物の近藤効果を初めて実証 --電子相関物性の設計・探索の新たなプラットホームを開拓--. 京都大学プレスリリース. 2022-01-31.Open access publication funded by the Max Planck Society.We present a comprehensive study of CaCu₃Ru₄O₁₂ using bulk sensitive hard and soft x-ray spectroscopy combined with local-density approximation + dynamical mean-field theory (DMFT) calculations. Correlation effects on both the Cu and Ru ions can be observed. From the Cu 2p core-level spectra, we deduce the presence of magnetic Cu²⁺ ions hybridized with a reservoir of itinerant electrons. The strong photon energy dependence of the valence band allows us to disentangle the Ru, Cu, and O contributions and, thus, to optimize the DMFT calculations. The calculated spin and charge susceptibilities show that the transition metal oxide CaCu₃Ru₄O₁₂ must be classified as a Kondo system and that the Kondo temperature is in the range of 500–1000 K
Hypersomnolence and Sleep-related Complaints in Metropolitan, Urban, and Rural Georgia
Persistent daytime hypersomnolence is associated with significant morbidity and mortality, but its prevalence in the population has been poorly documented. This study sought to characterize the prevalence of persistent daytime hypersomnolence, difficulties initiating and maintaining sleep, unrefreshing sleep, snoring, and the presence of physician-diagnosed sleep disorders in metropolitan, urban, and rural US Georgia populations. Between September 2004 and July 2005, a total of 6,530 randomly selected well and unwell adults, identified by screening interviews of 10,837 households (contacted by random digit dialing), completed a detailed phone interview. Sixteen percent reported persistent problems staying awake during the day; 26% reported persistent problems falling asleep at night; 31% experienced problems sleeping through the night; 34% were bothered by unrefreshing sleep; and 33% reported that they snored. In spite of the high occurrence of reported persistent sleep problems, only 10% of the survey participants reported having been diagnosed with a sleep disorder. These study findings highlight the need for increased public and clinician awareness with respect to proactively indentifying signs and symptoms of sleep disorders, a better understanding of their adverse impact upon morbidity and mortality, and their negative impact upon socioeconomic and academic potential
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