155 research outputs found

    Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa

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    We have constructed a pressure-temperature (PTP-T) phase diagram of PP-induced superconductivity in EuFe2_2As2_2 single crystals, via resistivity (ρ\rho) measurements up to 3.2 GPa. As hydrostatic pressure is applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at T0T_\mathrm{0} shifts to lower temperatures, and the corresponding resistive anomaly becomes undetectable for PP \ge 2.5 GPa. This suggests that the critical pressure PcP_\mathrm{c} where T0T_\mathrm{0} becomes zero is about 2.5 GPa. We have found that the AF order of the Eu2+^{2+} moments survives up to 3.2 GPa without significant changes in the AF ordering temperature TNT_\mathrm{N}. The superconducting (SC) ground state with a sharp transition to zero resistivity at TcT_\mathrm{c} \sim 30 K, indicative of bulk superconductivity, emerges in a pressure range from PcP_\mathrm{c} \sim 2.5 GPa to \sim 3.0 GPa. At pressures close to but outside the SC phase, the ρ(T)\rho(T) curve shows a partial SC transition (i.e., zero resistivity is not attained) followed by a reentrant-like hump at approximately TNT_\mathrm{N} with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like strain component is applied using a solid pressure medium, the partial superconductivity is continuously observed in a wide pressure range from 1.1 GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B, selected as "Editors' Suggestion

    Gastric Endocrine Cell Carcinoma with Long-Term Survival Developing Metachronous Remnant Cancer

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    A rare case of primary gastric endocrine cell carcinoma in a 79-year-old man is reported. Upper gastrointestinal endoscopy showed a large Bormann's type 2 tumour located in the middle of the stomach. On computed tomography, the gastric wall was thickened by the large tumour, and there were no distant metastases. Distal gastrectomy, lymph node dissection, and partial resection of the transverse colon were performed because the tumour involved the transverse mesocolon. The final pathological diagnosis was endocrine cell carcinoma, with tumour infiltration up to the subserous layer. Adjuvant chemotherapy was given, but metachronous remnant gastric cancer developed 2 years after surgery. Endoscopic submucosal dissection was performed for the early 0-IIc type gastric cancer, and the surgical margin was preserved. The patient has survived for 5 years after the primary surgery, remaining disease-free so far

    Cyclotron resonance and mass enhancement by electron correlation in KFe2_2As2_2

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    Cyclotron resonance (CR) measurements for the Fe-based superconductor KFe2_2As2_2 are performed. One signal for CR is observed, and is attributed to the two-dimensional α\alpha Fermi surface at the Γ\Gamma point. We found a large discrepancy in the effective masses of CR [(3.4±\pm0.05)mem_e (mem_e is the free electron mass)] and de-Haas van Alphen (dHvA) results, a direct evidence of mass enhancement due to electronic correlation. A comparison of the CR and dHvA results shows that both intra- and interband electronic correlations contribute to the mass enhancement in KFe2_2As2_2.Comment: 5 pages, 4 figure

    Diagnosing nocturnal frontal lobe epilepsy: A case study of two children

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    AbstractWe describe two children of nocturnal frontal lobe epilepsy (NFLE) diagnosed using carefully observed nocturnal sleep EEGs and detailed patient histories.Case #1, a 14-year-old boy, showed repeated generalized tonic convulsions and frequent eyes opening seizures during sleep. Conventional EEGs – done with the patient awake or in sleep stage I – showed no abnormalities, while a nocturnal sleep EEG – done during in sleep stage II – revealed the repeated, sharp wave bursts predominantly in the right frontal lobe characteristic of NFLE. During these wave bursts, we noticed the boy's eyes opening, although his parents had not been aware this NFLE symptom.Case #2, a 12-year-old boy, showed one daytime generalized convulsion. He had also been suffering from repeated paroxysmal episodes similar to parasomnia – waking up, sitting, walking, screaming, and speaking – which always followed the same patterns lasting several minutes. During the nocturnal sleep EEG, episodes occurred twice, showing abnormal epileptic discharges predominantly in the frontal lobe. His parents did not mention the episodes to us until questioned, as they had recognized them as parasomnia. The previous conventional EEG showed abnormal slow waves in the frontal lobe, which led us to suspect frontal lobe epilepsy and to take a detailed patient history.The frequency and stereotypy of their symptoms during sleep caused us to perform nocturnal sleep EEGs and led us NFLE diagnosis. Detailed patient histories including sleep habits and carefully observed nocturnal sleep EEGs enabled us to recognize these NFLE clinical features

    Person-centered dementia care during COVID-19: a qualitative case study of impact on and collaborations between caregivers

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    BackgroundLittle is known about the actual impact of COVID-19 on caregivers of older people with dementia and resultant collaborations among them to provide continued person-centered care while undertaking infection control measures. In this study, we explored the impact of providing dementia care during COVID-19 on caregivers involved in dementia care.MethodsThis is an exploratory qualitative case study. The participants were family members living with older people with dementia, care managers, and the medical and long-term care facility staff. Data were collected from 46 caregivers via face-to-face and semi-structured interviews and analyzed using thematic analysis.ResultsThe interviews identified 22 themes related to the impact of COVID-19 on different positions of the caregivers involved in dementia care and their collaboration, and we categorized them into six categories. The core themes were “re-acknowledgement of care priorities” and “rebuilding of relationships.” When caregivers’ perceptions were aligned in the decision-making processes regarding care priorities, “reaffirmation of trust” and “strengthening of intimate relationships” emerged as positive changes in their relationships. Furthermore, the differences in the ability of each caregiver to access and select correct and appropriate information about COVID-19, and the extent of infection spread in the region were related to “anxiety during COVID-19 pandemic” and caused a “gap in perception” regarding infection control.ConclusionsThe present study clarified that the process of aligning the perceptions of caregivers to the objectives and priorities of care for older people with dementia during COVID-19 pandemic strengthened the relationships among caregivers. The findings of this study are useful for caregivers involved in person-centered dementia care

    Bioorganic synthesis of a recombinant HIV-1 fusion inhibitor, SC35EK, with an N-terminal pyroglutamate capping group.

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    The bioorganic synthesis of an end-capped anti-HIV peptide from a recombinant protein was investigated. Cyanogen bromide-mediated cleavage of two Met-Gln sites across the target anti-HIV sequence generated an HIV-1 fusion inhibitor (SC35EK) analog bearing an N-terminal pyroglutamate (pGlu) residue and a C-terminal homoserine lactone (Hsl) residue. The end-capped peptide, pGlu-SC35EK-Hsl, had similar bioactivity and biophysical properties to the parent peptide, and an improved resistance to peptidase-mediated degradation was observed compared with the non-end-capped peptide obtained using standard recombinant technology

    Spatial infinity in higher dimensional spacetimes

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    Motivated by recent studies on the uniqueness or non-uniqueness of higher dimensional black hole spacetime, we investigate the asymptotic structure of spatial infinity in n-dimensional spacetimes(n4n \geq 4). It turns out that the geometry of spatial infinity does not have maximal symmetry due to the non-trivial Weyl tensor {}^{(n-1)}C_{abcd} in general. We also address static spacetime and its multipole moments P_{a_1 a_2 ... a_s}. Contrasting with four dimensions, we stress that the local structure of spacetimes cannot be unique under fixed a multipole moments in static vacuum spacetimes. For example, we will consider the generalized Schwarzschild spacetimes which are deformed black hole spacetimes with the same multipole moments as spherical Schwarzschild black holes. To specify the local structure of static vacuum solution we need some additional information, at least, the Weyl tensor {}^{(n-2)}C_{abcd} at spatial infinity.Comment: 6 pages, accepted for publication in Physical Review D, published versio
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