341 research outputs found

    Hole Transport in p-Type ZnO

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    A two-band model involving the A- and B-valence bands was adopted to analyze the temperature dependent Hall effect measured on N-doped \textit{p}-type ZnO. The hole transport characteristics (mobilities, and effective Hall factor) are calculated using the ``relaxation time approximation'' as a function of temperature. It is shown that the lattice scattering by the acoustic deformation potential is dominant. In the calculation of the scattering rate for ionized impurity mechanism, the activation energy of 100 or 170 meV is used at different compensation ratios between donor and acceptor concentrations. The theoretical Hall mobility at acceptor concentration of 7×10187 \times 10^{18} cm3^3 is about 70 cm2^2V1^{-1}s1^{-1} with the activation energy of 100 meV and the compensation ratio of 0.8 at 300 K. We also found that the compensation ratios conspicuously affected the Hall mobilities.Comment: 5page, 5 figures, accepted for publication in Jpn. J. Appl. Phy

    Clinical Features of Oral Multiple Primary Carcinomas Compared with Oral Single Primary Carcinoma

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    [Background] Owing to the increase in the older population and the increased life span, the number of patients with oral multiple primary carcinomas will increase. Predicting the second and third carcinoma clinically is difficult, and the presence of second or third carcinomas is a factor that determines the prognosis of oral carcinoma. In this study, we examined the clinical features of oral multiple primary carcinomas treated in our department. [Methods] We retrospectively reviewed the medical records of patients with oral squamous cell carcinoma who underwent radical treatment at and were followed by the Department of Oral and Maxillofacial Surgery, Tottori University Hospital from January 2003 to October 2017. [Results] This study included 261 patients: 241 patients had oral single primary carcinoma and 20 patients had oral multiple primary carcinomas. Oral multiple primary carcinomas showed female predilection and occurred more frequently in the lower gingiva and significantly less frequently in the tongue (P < 0.01). Oral multiple primary carcinomas showed a significantly higher recurrence rate (P < 0.01). The 5-year overall survival of oral single primary carcinoma patients was 88.0% compared with 95% for oral multiple primary carcinomas, with no significant difference (log rank test, P = 0.54). However, the 15-year survival rate dropped to 28.1% in oral multiple primary carcinomas. The cumulative disease incidence rates of metachronous second primary carcinoma from first carcinoma at 5 years and 10 years were 3.45% and 5.36%, respectively. [Conclusion] Oral multiple primary carcinomas rarely occur in the tongue. The 5-year survival rate showed no difference between single and multiple carcinoma patients, but over longer observation, the prognosis of multiple carcinoma was poor owing to a high recurrence rate. Because of the high recurrence rate and risk of further metachronous carcinoma in oral multiple primary carcinomas, longer-term follow-up is required

    経験類似度に基づくボラティリティ予測

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    要旨あり高頻度金融データに基づく統計的推測とモデリング原著論

    Behavioral Alterations in Response to Fear-Provoking Stimuli and Tranylcypromine Induced by Perinatal Exposure to Bisphenol A and Nonylphenol in Male Rats

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    The purpose of this study was to examine whether perinatal exposure to two major environmental endocrine-disrupting chemicals, bisphenol A (BPA; 0.1 mg/kg/day orally) and nonylphenol [NP; 0.1 mg/kg/day (low dose) and 10 mg/kg/day (high dose) orally] daily from gestational day 3 to postnatal day 20 (transplacental and lactational exposures) would lead to behavioral alterations in the male offspring of F344 rats. Neither BPA nor NP exposure affected behavioral characteristics in an open-field test (8 weeks of age), in a measurement of spontaneous motor activity (12 weeks of age), or in an elevated plus-maze test (14 weeks of age). A passive avoidance test (13 weeks of age) showed that both BPA- and NP-treated offspring tended to delay entry into a dark compartment. An active avoidance test at 15 weeks of age revealed that BPA-treated offspring showed significantly fewer avoidance responses and low-dose NP-treated offspring exhibited slightly fewer avoidance responses. Furthermore, BPA-treated offspring significantly increased the number of failures to avoid electrical unconditioned stimuli within 5-sec electrical shock presentation compared with the control offspring. In a monoamine-disruption test using 5 mg/kg (intraperitoneal) tranylcypromine (Tcy), a monoamine oxidase inhibitor, both BPA-treated and low-dose NP-treated offspring at 22–24 weeks of age failed to show a significant increment in locomotion in response to Tcy, whereas control and high-dose NP-treated offspring significantly increased locomotion behavior after Tcy injection. In addition, when only saline was injected during a monoamine-disruption test, low-dose NP-treated offspring showed frequent rearing compared with the control offspring. The present results indicate that perinatal low-dose BPA or NP exposure irreversibly influenced the reception of fear-provoking stimuli (e.g., electrical shock), as well as monoaminergic neural pathways

    Association between Mammographic Breast Density and Lifestyle in Japanese Women

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    A high mammographic breast density is considered to be a risk factor for breast cancer. However, only a small number of studies on the association between breast density and lifestyle have been performed. A cross-sectional study was performed using a survey with 29 questions on life history and lifestyle. The breast density on mammography was classified into 4 categories following the BI-RADS criteria. The subjects were 522 women with no medical history of breast cancer. The mean age was 53.3 years old. On multivariate analysis, only BMI was a significant factor determining breast density in premenopausal women (parameter estimate, -0.403;p value, 0.0005), and the density decreased as BMI rose. In postmenopausal women, BMI (parameter estimate, -0.196;p value, 0.0143) and number of deliveries (parameter estimate, -0.388;p value, 0.0186) were significant factors determining breast density;breast density decreased as BMI and number of deliveries increased. Only BMI and number of deliveries were identified as factors significantly influencing breast density. BMI was inversely correlated with breast density before and after menopause, whereas the influence of number of deliveries on breast density was significant only in postmenopausal women in their 50 and 60s

    Effects of lifestyle and single nucleotide polymorphisms on breast cancer risk: a case-control study in Japanese women

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    Background: Lifestyle factors, including food and nutrition, physical activity, body composition and reproductive factors, and single nucleotide polymorphisms (SNPs) are associated with breast cancer risk, but few studies of these factors have been performed in the Japanese population. Thus, the goals of this study were to validate the association between reported SNPs and breast cancer risk in the Japanese population and to evaluate the effects of SNP genotypes and lifestyle factors on breast cancer risk. Methods: A case-control study in 472 patients and 464 controls was conducted from December 2010 to November 2011. Lifestyle was examined using a self-administered questionnaire. We analyzed 16 breast cancer-associated SNPs based on previous GWAS or candidate-gene association studies. Age or multivariate-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were estimated from logistic regression analyses. Results: High BMI and current or former smoking were significantly associated with an increased breast cancer risk, while intake of meat, mushrooms, yellow and green vegetables, coffee, and green tea, current leisure-time exercise, and education were significantly associated with a decreased risk. Three SNPs were significantly associated with a breast cancer risk in multivariate analysis: rs2046210 (per allele OR = 1.37 [95% CI: 1.11-1.70]), rs3757318 (OR = 1.33[1.05-1.69]), and rs3803662 (OR = 1.28 [1.07-1.55]). In 2046210 risk allele carriers, leisure-time exercise was associated with a significantly decreased risk for breast cancer, whereas current smoking and high BMI were associated with a significantly decreased risk in non-risk allele carriers. Conclusion: In Japanese women, rs2046210 and 3757318 located near the ESR1 gene are associated with a risk of breast cancer, as in other Asian women. However, our findings suggest that exercise can decrease this risk in allele carriers

    Changes in Corrected QT Interval May Be Associated with Clinical Responses in Burning Mouth Syndrome

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    Backgrounds: Burning mouth syndrome (BMS) is characterized by a burning sensation of the oral mucosa in the absence of underlying dental causes. Only a minority of BMS patients will achieve satisfactory pain relief and little is known about clinical makers for the response. The objective of this study was to consider whether corrected QT interval (QTc) is a useful biomarker for clinical responses. Methods: We conducted a single-center retrospective observational study and evaluated 51 BMS patients treated with amitriptyline. We calculated QTc changes with amitriptyline and examined the relationship between changes in QTc and visual analogue scale (VAS). Results: Of 51 subjects, 13 (25.5%) were amitriptyline-responders and 38 (74.5%) were non-responders. The changes in QTc interval were significantly correlated with changes in VAS (Spearman's rank correlation coefficient r = 0.389, p = 0.006). Conclusions: Changes in QTc interval may be a non-invasive estimation of clinical responses in BMS patients

    Overexpression of Cortactin Increases Invasion Potential in Oral Squamous Cell Carcinoma.

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    Cortactin, an F-actin binding protein, stabilizes F-actin networks and promotes actin polymerization by activating the Arp2/3 complex. Overexpression of cortactin has been reported in several human cancers. Cortactin stimulates cell migration, invasion, and experimental metastasis. However, the underlying mechanism is not still understood. In the present study, we therefore evaluated the possibility that cortactin could be appropriate as a molecular target for cancer gene therapy. In 70 primary oral squamous cell carcinomas and 10 normal oral mucosal specimens, cortactin expression was evaluated by immunological analyses, and the correlations of the overexpression of cortactin with clinicopathologic factors were evaluated. Overexpression of cortactin was detected in 32 of 70 oral squamous cell carcinomas; significantly more frequently than in normal oral mucosa. Cortactin overexpression was more frequent in higher grade cancers according to T classification, N classifications, and invasive pattern. Moreover, RNAi-mediated decrease in cortactin expression reduced invasion. Downregulation of cortactin expression increased the expression levels of E-cadherin, beta-catenin, and EpCAM. The siRNA of cortactin also reduced PTHrP expression via EGF signaling. These results consistently indicate that the overexpression of cortactin is strongly associated with an aggressive phenotype of oral squamous cell carcinoma. In conclusion, we propose that cortactin could be a potential molecular target of gene therapy by RNAi targeting in oral squamous cell carcinoma

    Radiative B-L symmetry breaking and the Z' mediated SUSY breaking

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    We explore a mechanism of radiative B-L symmetry breaking in analogous to the radiative electroweak symmetry breaking. The breaking scale of B-L symmetry is related to the neutrino masses through the see-saw mechanism. Once we incorporate the U(1)_{B-L} gauge symmetry in SUSY models, the U(1)_{B-L} gaugino appears, and it can mediate the SUSY breaking (Z-prime mediated SUSY breaking) at around the scale of 10^6 GeV. Then we find a links between the neutrino mass (more precisly the see-saw or B-L scale of order 10^{6} GeV) and the Z-prime mediated SUSY breaking scale. It is also very interesting that the gluino at the weak scale becomes relatively light, and almost compressed mass spectra for the gaugino sector can be realized in this scenario, which is very interesting in scope of the LHC.Comment: 20 pages, 5 figures; the version to appear in Phys. Lett.
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