268 research outputs found

    Localised surface plasmon resonance inducing cooperative Jahn–Teller effect for crystal phase-change in a nanocrystal

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    結晶中の電子の集団的な運動が原子を動かすプラズモン誘起原子変位を初めて発見 --見えない光学センサーなど新技術の実現に期待--. 京都大学プレスリリース. 2023-08-01.The Jahn–Teller effect, a phase transition phenomenon involving the spontaneous breakdown of symmetry in molecules and crystals, causes important physical and chemical changes that affect various fields of science. In this study, we discovered that localised surface plasmon resonance (LSPR) induced the cooperative Jahn–Teller effect in covellite CuS nanocrystals (NCs), causing metastable displacive ion movements. Electron diffraction measurements under photo illumination, ultrafast time-resolved electron diffraction analyses, and theoretical calculations of semiconductive plasmonic CuS NCs showed that metastable displacive ion movements due to the LSPR-induced cooperative Jahn–Teller effect delayed the relaxation of LSPR in the microsecond region. Furthermore, the displacive ion movements caused photo-switching of the conductivity in CuS NC films at room temperature (22 °C), such as in transparent variable resistance infrared sensors. This study pushes the limits of plasmonics from tentative control of collective oscillation to metastable crystal structure manipulation

    Lower FEV1 in non-COPD, nonasthmatic subjects: association with smoking, annual decline in FEV1, total IgE levels, and TSLP genotypes

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    Few studies have investigated the significance of decreased FEV1 in non-COPD, nonasthmatic healthy subjects. We hypothesized that a lower FEV1 in these subjects is a potential marker of an increased susceptibility to obstructive lung disease such as asthma and COPD. This was a cross-sectional analysis of 1505 Japanese adults. We divided the population of healthy adults with no respiratory diseases whose FEV1/FVC ratio was ≥70% (n = 1369) into 2 groups according to their prebronchodilator FEV1 (% predicted) measurements: <80% (n = 217) and ≥80% (n = 1152). We compared clinical data – including gender, age, smoking habits, total IgE levels, and annual decline of FEV1 – between these 2 groups. In addition, as our group recently found that TSLP variants are associated with asthma and reduced lung function, we assessed whether TSLP single nucleotide polymorphisms (SNPs) were associated with baseline lung function in non-COPD, nonasthmatic healthy subjects (n = 1368). Although about half of the subjects with lower FEV1 had never smoked, smoking was the main risk factor for the decreased FEV1 in non-COPD, nonasthmatic subjects. However, the subjects with lower FEV1 had a significantly higher annual decline in FEV1 independent of smoking status. Airflow obstruction was associated with increased levels of total serum IgE (P = 0.029) and with 2 functional TSLP SNPs (corrected P = 0.027–0.058 for FEV1% predicted, corrected P = 0.015–0.033 for FEV1/FVC). This study highlights the importance of early recognition of a decreased FEV1 in healthy subjects without evident pulmonary diseases because it predicts a rapid decline in FEV1 irrespective of smoking status. Our series of studies identified TSLP variants as a potential susceptibility locus to asthma and to lower lung function in non-COPD, nonasthmatic healthy subjects, which may support the contention that genetic determinants of lung function influence susceptibility to asthma

    Neurovascular Compression in Atypical Odontalgia Patients

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    Background. Persistent idiopathic facial pain (PIFP) is the unexplained pain along the territory of the trigeminal nerve, including nonorganic tooth pain called atypical odontalgia (AO). Though PIFP is debilitating to patients’ livelihood and well-being, its pathophysiology remains poorly understood. Although neurovascular compression (NVC) of the trigeminal nerve is known to be associated with trigeminal neuralgia (TN), the relationship between NVC and other orofacial pains has not been fully elucidated. Methods. In this study, we investigated the differences in the characteristics of PIFP (primarily AO) patients in the presence or absence of NVC. A retrospective analysis was performed on data from 121 consecutive patients who had been diagnosed with unilateral PIFP according to the criteria of the International Classification of Headache Disorders (ICHD)–3 and underwent magnetic resonance imaging scans of the head. Results. In the group without NVC, characteristic findings were significant for psychiatric morbidity, somatization, and pain disability, when compared with the group with NVC. Furthermore, the group without NVC exhibited significant headache, noncardiac chest pain, shortness of breath, and pain catastrophizing. Conclusions. These results suggest that PIFP patients can be divided into two groups: one consistent with a neuropathic pain phenotype when NVC is present and a functional somatic symptom phenotype when presenting without NVC. Our findings may enable a more precise understanding of pathophysiology of PIFP and lead to better treatment strategies

    Electronic structure of multiferroic BiFeO3 by resonant soft x-ray emission spectroscopy

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    [[abstract]]The electronic structure of multiferroic BiFeO3 has been studied using soft x-ray emission spectroscopy. The fluorescence spectra exhibit that the valence band is mainly composed of O 2p state hybridized with Fe 3d state. The band gap corresponding to the energy separation between the top of the O 2p valence band and the bottom of the Fe 3d conduction band is 1.3 eV. The soft x-ray Raman scattering reflects the features due to the charge-transfer transition from O 2p valence band to Fe 3d conduction band. These findings are similar to the result of electronic structure calculation by density-functional theory within the local spin-density approximation that included the effect of Coulomb repulsion between localized d states.[[booktype]]紙本[[booktype]]電子

    A clinicopathological study of perineural invasion and vascular invasion in oral tongue squamous cell carcinoma

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    The risk factors for recurrence of head and neck cancer are classified as being of high or intermediate risk. Those of intermediate risk include multiple positive nodes without extracapsular nodal spread, perineural/vascular invasion, pT3/T4 primary tumours, and positive level IV/V nodes. However, little evidence is available to validate these intermediate risk factors. We analyzed perineural/vascular invasion in 89 patients who underwent radical surgery for oral tongue squamous cell carcinoma, whose records were reviewed retrospectively. Perineural invasion was found in 27.0% of cases and vascular invasion in 23.6%; both had a strong relationship with histopathological nodal status (P = 0.005). The 5-year disease-specific survival (DSS) and overall survival rates of patients with perineural invasion were significantly lower than those of patients without perineural invasion (P < 0.001 and P = 0.002, respectively). The 5-year DSS of UICC stage I and II cases with perineural/vascular invasion was significantly lower than those without (P < 0.001 and P = 0.008, respectively). Perineural invasion and vascular invasion are risk factors for regional metastasis and a poor prognosis. We recommend elective neck dissection when perineural/vascular invasion is found in clinical stage I and II cases. The accumulation of further evidence to consider intermediate risks is required

    Oral carcinoma: Clinical evaluation using diffusion kurtosis imaging and its correlation with histopathologic findings

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    PURPOSE: In this study, we aimed to determine the usefulness of diffusion kurtosis imaging (DKI) as a noninvasive method for evaluation of the histologic grade and lymph node metastasis in patients with oral carcinoma. MATERIALS AND METHODS: Twenty-seven patients with oral carcinoma were examined with a 3-T MR system and 16-channel coil. DKI data were obtained by a single-shot echo-planar imaging sequence with repetition time, 10,000ms; echo time, 94ms; field of view, 250x204.25ms; matrix, 120x98; section thickness, 4mm; four b values of 0, 500, 1000, and 2000s/mm(2); and motion-probing gradients in three orthogonal directions. Diffusivity (D) and kurtosis (K) were calculated using the equation: S=S0 exp(-b D+b(2) D(2) K/6). Conventional apparent diffusion coefficient (ADC) was also calculated. The MR images were compared with the histopathologic findings. RESULTS: Relative to the histologic grades (Grades 1, 2, and 3) of the 27 oral carcinomas, D values showed a significant inverse correlation (r=-0.885; P<0.001) and K values showed a significant positive correlation (r=0.869; P<0.001), whereas ADC values showed no significant correlation (r=-0.311; P=0.115). When comparing between metastatic and non-metastatic lymph nodes, significant differences in the D values (P<0.001) and K values (P<0.001), but not the ADC values (P=0.110) became apparent. CONCLUSIONS: In patients with oral carcinoma, DKI seems to be clinically useful for the evaluation of histologic grades and lymph node metastasis

    Genetic association of the functional CDHR3 genotype with early-onset adult asthma in Japanese populations

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    BackgroundRecent studies have demonstrated that a coding SNP (rs6967330, Cys529→Tyr) in cadherin-related family member 3 (CDHR3), which was previously associated with wheezing illness and hospitalizations in infancy, could support efficient human rhinovirus C (RV-C) entry and replication. Here, we sought to examine the genetic contribution of this variant to the development of adult asthma.MethodsWe performed a candidate gene case–control association study of 2 independent Japanese populations (a total of 3366 adults). The odds ratios (ORs) for association of the A allele at rs6967330 with adult asthma were calculated according to age at onset of asthma. In addition, the effect of the CDHR3 genotype on the development of specific asthma phenotypes was examined.ResultsThe A allele was associated with asthma (OR = 1.56; Mantel–Haenszel p = 0.0040) when the analysis was limited to patients with early-onset adult asthma. In addition, when the analysis was limited to atopic individuals, a stronger association of the CDHR3 variant with early-onset asthma was found, and interaction of the CDHR3 genotype with atopy was demonstrated. Finally, a significant association of this variant was specifically found with a phenotype of asthma characterized by atopy, early-onset, and lower lung function.ConclusionsOur study supports the concept that the CDHR3 variant is an important susceptibility factor for severe adult asthma in individuals who develop the disease in early life. The interaction between the CDHR3 variant and atopy indicates that genetic predisposition to early respiratory viral infection is combined with atopy in promoting asthma
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