554 research outputs found

    Evidence for charge delocalization crossover in the quantum critical superconductor CeRhIn5_5

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    The nature of charge degrees-of-freedom distinguishes scenarios for interpreting the character of a second order magnetic transition at zero temperature, that is, a magnetic quantum critical point (QCP). Heavy-fermion systems are prototypes of this paradigm, and in those, the relevant question is where, relative to a magnetic QCP, does the Kondo effect delocalize their ff-electron degrees-of-freedom. Herein, we use pressure-dependent Hall measurements to identify a finite-temperature scale ElocE_\text{loc} that signals a crossover from ff-localized to ff-delocalized character. As a function of pressure, Eloc(P)E_\text{loc}(P) extrapolates smoothly to zero temperature at the antiferromagnetic QCP of CeRhIn5_5 where its Fermi surface reconstructs, hallmarks of Kondo-breakdown criticality that generates critical magnetic and charge fluctuations. In 4.4% Sn-doped CeRhIn5_5, however, Eloc(P)E_\text{loc}(P) extrapolates into its magnetically ordered phase and is decoupled from the pressure-induced magnetic QCP, which implies a spin-density-wave (SDW) type of criticality that produces only critical fluctuations of the SDW order parameter. Our results demonstrate the importance of experimentally determining ElocE_\text{loc} to characterize quantum criticality and the associated consequences for understanding the pairing mechanism of superconductivity that reaches a maximum TcT_\text{c} in both materials at their respective magnetic QCP.Comment: 19 pages, 5 figures, published in Nature Communication

    Effect of two different exercises on balance, pain and ankle motor function in male college students with chronic ankle instability

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    Strength and proprioceptive exercise are known to be representative exercise methods used in patients with chronic ankle instability (CAI) and they are effective in restoring ankle stability and body balance, which gets reduced by repetitive ankle sprains. But, there is a lack of data comparing the effects of strengthening or proprioceptive exercise rehabilitation program for CAI patients. The purpose of this study is to investigate the effect of a 4-week exercise program on ankle range of motion (ROM), static/dynamic balance, and drop landing in college students with CAI. The subjects of this study were 21 male college students who had the Cumberland ankle instability tool (CAIT) questionnaire scores of 24 or less, and they were divided into three groups; the non-treated group (NTG), the traditional strength exercise group (SEG) and the proprioceptive exercise group (PEG). The exercise rehabilitation program was applied 3 times a week for 4 weeks. To examine the difference between groups, CAIT, visual analogue scale (VAS), body composition, ankle ROM, one-leg standing with eyes closed and Y-balance test (YBT) as well as center of pressure (COP) 95% confidence ellipse area during drop landing were measured before and after the exercise intervention. CAIT scores and static balance were significantly increased in the PEG compared to the NTG and the SEG, and ankle dorsiflexion ROM and Y-balance were significantly increased in the SEG and the PEG compared to the NTG. In addition, pain, ankle inversion ROM, and COP 95% confidence ellipse area were significantly reduced in the SEG and the PEG compared to the NTG. The proprioceptive exercise program is thought to be effective therapeutic approach on improving the symptoms of CAI patients

    Critical-point anomalies in doped CeRhIn5

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    The heavy-fermion compound CeRhIn5_5 can be tuned through a quantum critical point, when In is partially replaced by Sn. This way additional charge carriers are introduced and the antiferromagnetic order is gradually suppressed to zero temperature. Here we investigate the temperature-dependent optical properties of CeRh(In1x_{1-x}Snx_x)5_5 single crystals for x=4.4%x = 4.4\%, 6.9%6.9\% and 9.8%9.8\%. With increasing Sn concentration the infrared conductivity reveals a clear enhancement of the cc-ff hybridization strength. At low temperatures we observed a non-Fermi-liquid behavior in the frequency dependence of the scattering rate and effective mass in all three compounds. In addition, below a characteristic temperature T10T^* \approx 10 K, the temperature dependent resistivity ρ(T)\rho(T) follows a logT\log T behavior, typical for a non-Fermi liquid. The temperature-dependent magnetization also exhibits anomalous behavior below TT^*. Our investigation reveal that below TT^* the system shows a pronounced non-Fermi-liquid behavior and TT^* monotonically increases as the quantum critical point is approached

    Structural and histological characterization of oviductal magnum and lectin-binding patterns in Gallus domesticus

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    <p>Abstract</p> <p>Background</p> <p>Although chicken oviduct is a useful model and target tissue for reproductive biology and transgenesis, little is known because of the highly specific hormonal regulation and the lack of fundamental researches, including lectin-binding activities and glycobiology. Because lectin is attached to secreted glycoproteins, we hypothesized that lectin could be bound to secretory egg-white proteins, and played a crucial role in the generation of egg-white protein in the oviduct. Hence, the purpose of this study was to investigate the structural, histological and lectin-binding characteristics of the chicken oviductal magnum from juvenile and adult hens.</p> <p>Methods</p> <p>The oviductal magnums from juvenile and adult hens were prepared for ultrastructural analysis, qRT-PCR and immunostaining. Immunohistochemistry of anti-ovalbumin, anti-ESR1 and anti-PGR, and mRNA expression of egg-white genes and steroid hormone receptor genes were evaluated. Lectin histochemical staining was also conducted in juvenile and adult oviductal magnum tissues.</p> <p>Results</p> <p>The ultrastructural analysis showed that ciliated cells were rarely developed on luminal surface in juvenile magnum, but not tubular gland cells. In adult magnum, two types of epithelium and three types of tubular gland cells were observed. qRT-PCR analysis showed that egg-white genes were highly expressed in adult oviduct compared with the juvenile. However, mRNA expressions of <it>ESR1 </it>and <it>PGR </it>were considerably higher in juvenile oviduct than adult (<it>P </it>< 0.05). The immunohistochemical analysis showed that anti-ovalbumin antibody was detected in adult oviduct not in juvenile, unlikely anti-ESR1 and anti-PGR antibodies that were stained in both oviducts. In histological analysis, Toluidine blue was stained in juvenile and adult oviductal epithelia, and adult tubular glands located in the outer layer of oviductal magnum. In contrast, PAS was positive only in adult oviductal tubular gland. Lectins were selectively bound to oviductal epithelium, stroma, and tubular gland cells. Particularly, lectin-ConA and WGA were bound to electron-dense secretory granules in tubular gland.</p> <p>Conclusions</p> <p>The observation of ultrastructural analysis, mRNA expression, immunohistochemistry and lectin staining showed structural and physiological characterization of juvenile and adult oviductal magnum. Consequently, oviduct study could be helped to <it>in vitro </it>culture of chicken oviductal cells, to develop epithelial or tubular gland cell-specific markers, and to understand female reproductive biology and endocrinology.</p

    Appropriate number of observations for determining hand hygiene compliance among healthcare workers

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    Abstract We sought to determine the minimum number of observations needed to determine hand hygiene (HH) compliance among healthcare workers. The study was conducted at a referral hospital in South Korea. We retrospectively analyzed the result of HH monitoring from January to December 2018. HH compliance was calculated by dividing the number of observed HH actions by the total number of opportunities. Optimal HH compliance rates were calculated based on adherence to the six-step technique recommended by the World Health Organization. The minimum number of required observations (n) was calculated by the following equation using overall mean value (ρ), absolute precision (d), and confidence interval (CI) (1 − α) [the equation: nZα/22×ρ×(1ρ)/d2{\text{n}} \ge Z_{\alpha /2}^{2} \times \rho \times \left( {1 - \rho } \right)/d^{2} n ≥ Z α / 2 2 × ρ × 1 - ρ / d 2 ]. We considered ds of 5%, 10%, 20%, and 30%, with CIs of 99%, 95%, and 90%. During the study period, 8791 HH opportunities among 1168 healthcare workers were monitored. Mean HH compliance and optimal HH compliance rates were 80.3% and 59.7%, respectively. The minimum number of observations required to determine HH compliance rates ranged from 2 ( dd d : 30%, CI: 90%) to 624 ( dd d : 5%, CI: 99%), and that for optimal HH compliance ranged from 5 ( dd d : 30%, CI: 90%) to 642 ( dd d : 5%, CI: 99%). Therefore, we found that our hospital required at least five observations to determine optimal HH compliance

    Triple-sinusoid hedgehog lattice in a centrosymmetric Kondo metal

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    Superposed symmetry-equivalent magnetic ordering wave vectors can lead to topologically non-trivial spin textures, such as magnetic skyrmions and hedgehogs, and give rise to novel quantum phenomena due to fictitious magnetic fields associated with a non-zero Berry curvature of these spin textures. To date, all known spin textures are constructed through the superposition of multiple spiral orders, where spins vary in directions with constant amplitude. Recent theoretical studies have suggested that multiple sinusoidal orders, where collinear spins vary in amplitude, can construct distinct topological spin textures regarding chirality properties. However, such textures have yet to be experimentally realised. In this work, we report the observation of a zero-field magnetic hedgehog lattice from a superposition of triple sinusoidal wave vectors in the magnetically frustrated Kondo lattice CePtAl4Ge2. Notably, we also observe the emergence of anomalous electrical and thermodynamic behaviours near the field-induced transition from the zero-field topological hedgehog lattice to a non-topological sinusoidal state. These observations highlight the role of Kondo coupling in stabilising the zero-field hedgehog state in the Kondo lattice and warrant an expedited search for other topological magnetic structures coupled with Kondo coupling

    Progress in Understanding and Sequencing the Genome of Brassica rapa

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    Brassica rapa, which is closely related to Arabidopsis thaliana, is an important crop and a model plant for studying genome evolution via polyploidization. We report the current understanding of the genome structure of B. rapa and efforts for the whole-genome sequencing of the species. The tribe Brassicaceae, which comprises ca. 240 species, descended from a common hexaploid ancestor with a basic genome similar to that of Arabidopsis. Chromosome rearrangements, including fusions and/or fissions, resulted in the present-day “diploid” Brassica species with variation in chromosome number and phenotype. Triplicated genomic segments of B. rapa are collinear to those of A. thaliana with InDels. The genome triplication has led to an approximately 1.7-fold increase in the B. rapa gene number compared to that of A. thaliana. Repetitive DNA of B. rapa has also been extensively amplified and has diverged from that of A. thaliana. For its whole-genome sequencing, the Brassica rapa Genome Sequencing Project (BrGSP) consortium has developed suitable genomic resources and constructed genetic and physical maps. Ten chromosomes of B. rapa are being allocated to BrGSP consortium participants, and each chromosome will be sequenced by a BAC-by-BAC approach. Genome sequencing of B. rapa will offer a new perspective for plant biology and evolution in the context of polyploidization

    Orbital-selective confinement effect of Ru 4d4d orbitals in SrRuO3_3 ultrathin film

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    The electronic structure of SrRuO3_3 thin film with thickness from 50 to 1 unit cell (u.c.) is investigated via the resonant inelastic x-ray scattering (RIXS) technique at the O K-edge to unravel the intriguing interplay of orbital and charge degrees of freedom. We found that orbital-selective quantum confinement effect (QCE) induces the splitting of Ru 4d4d orbitals. At the same time, we observed a clear suppression of the electron-hole continuum across the metal-to-insulator transition (MIT) occurring at the 4 u.c. sample. From these two clear observations we conclude that QCE gives rise to a Mott insulating phase in ultrathin SrRuO3_3 films. Our interpretation of the RIXS spectra is supported by the configuration interaction calculations of RuO6_6 clusters.Comment: 7 pages, 7 figure
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