Blue light-emitting diode based on ZnO

A near-band-edge bluish electroluminescence (EL) band centered at around 440 nm was observed from ZnO p-i-n homojunction diodes through a semi-transparent electrode deposited on the p-type ZnO top layer. The EL peak energy coincided with the photoluminescence peak energy of an equivalent p-type ZnO layer, indicating that the electron injection from the n-type layer to the p-type layer dominates the current, giving rise to the radiative recombination in the p-type layer. The imbalance in charge injection is considered to originate from the lower majority carrier concentration in the p-type layer, which is one or two orders of magnitude lower than that in the n-type one. The current-voltage characteristics showed the presence of series resistance of several hundreds ohms, corresponding to the current spread resistance within the bottom n-type ZnO. The employment of conducting ZnO substrates may solve the latter problem.Comment: 13 pages, 4 figures. Jpn. J. Appl. Phys. in pres

The thyroid function of Graves' disease patients is aggravated by depressive personality during antithyroid drug treatment

<p>Abstract</p> <p>Background</p> <p>We previously reported that depressive personality (the scores of hypochondriasis, depression and psychasthenia determined by the Minnesota Multiphasic Personality Inventory (MMPI)) and daily hassles of Graves' disease (GD) patients treated long trem with antithyroid drug (ATD) were significantly higher in a relapsed group than in a remitted group, even in the euthyroid state. The present study aims to examine the relationship among depressive personality, emotional stresses, thyroid function and the prognosis of hyperthyroidism in newly diagnosed GD patients.</p> <p>Methods</p> <p>Sixty-four untreated GD patients responded to the MMPI for personality traits, the Natsume's Stress Inventory for major life events, and the Hayashi's Daily Life Stress Inventory for daily life stresses before and during ATD treatment.</p> <p>Results</p> <p>In the untreated thyrotoxic state, depressive personality (T-scores of hypochondriasis, depression or psychasthenia greater than 60 points in MMPI) were found for 44 patients (69%). For 15 (23%) of these patients, the scores decreased to the normal range after treatment. However, depressive personality persisted after treatment in the remaining 29 patients (46%). Normal scores before treatment were found for 20 patients (31%), and the scores were persistently normal for 15 patients (23%). The remaining 5 patients (8%) had higher depressive personality after treatment. Such depressive personality was not associated with the severity of hyperthyroidism. Serum TSH receptor antibody activity at three years after treatment was significantly (p = 0.0351) greater in the depression group than in the non- depression group. The remission rate at four years after treatment was significantly (p = 0.0305) lower in the depression group than in the non- depression group (22% vs 52%).</p> <p>Conclusion</p> <p>The data indicate that in GD patients treated with ATD, depressive personality during treatment reflects the effect of emotional stress more than that of thyrotoxicosis and that it aggravates hyperthyroidism. Psychosomatic therapeutic approaches including antipsychiatric drugs and/or psychotherapy appears to be useful for improving the prognosis of hyperthyroidism.</p

Spectral transitions of an ultraluminous X-ray source, NGC 2403 Source 3

Suzaku observation of an ultraluminous X-ray source, NGC 2403 Source 3, performed on 2006 March 16--17, is reported. The Suzaku XIS spectrum of Source 3 was described with a multi-color black-body-like emission from an optically thick accretion disk. The innermost temperature and radius of the accretion disk was measured to be $T_{\rm in} = 1.08_{-0.03}^{+0.02}$ keV and $R_{\rm in} = 122.1_{-6.8}^{+7.7} \alpha^{1/2}$ km, respectively, where $\alpha = (\cos 60^\circ /\cos i)$ with $i$ being the disk inclination. The bolometric luminosity of the source was estimated to be $L_{\rm bol} = 1.82 \times 10^{39} \alpha$ ergs s$^{-1}$. Archival Chandra and XMM-Newton data of the source were analyzed for long-term spectral variations. In almost all observations, the source showed multi-color black-body-like X-ray spectra with parameters similar to those in the Suzaku observation. In only one Chandra observation, however, Source 3 was found to exhibit a power-law-like spectrum, with a photon index of $\Gamma = 2.37 \pm 0.08$, when it was fainter by about $\sim 15$ than in the Suzaku observation. The spectral behavior is naturally explained in terms of a transition between the slim disk state and the "very high" states, both found in Galactic black hole binaries when their luminosity approach the Eddington limit. These results are utilized to argue that ultraluminous X-ray sources generally have significantly higher black-hole masses than ordinary stellar-mass black holes.Comment: Accepted for PASJ 3nd Suzaku special issu

Electronic Structure and Electron Correlation in LaFeAsO_{1-x}F_x and LaFePO_{1-x}F_x

Photoemission spectroscopy is used to investigate the electronic structure of the newly discovered iron-based superconductors LaFeAsO_{1-x}F_x and LaFePO_{1-x}F_x. Line shapes of the Fe 2p core-level spectra suggest an itinerant character of Fe 3d electrons. The valence-band spectra are generally consistent with band-structure calculations except for the shifts of Fe 3d-derived peaks toward the Fermi level. From spectra taken in the Fe 3p -> 3d core-absorption region, we have obtained the experimental Fe 3d partial density of states, and explained it in terms of a band-structure calculation with a phenomenological self-energy correction, yielding a mass renormalization factor of ~< 2.Comment: 4 pages, 5 figure

Primary Follicular Lymphoma of the Duodenum with Erosions as Atypical Macroscopic Features

A 52-year-old Japanese woman who was eventually diagnosed with primary follicular lymphoma of the duodenum showed atypical endoscopic features, namely, erosions with peripheral whitish edematous mucosa. Initial biopsy specimens taken from the erosions revealed insufficient numbers of lymphoma cells for histological diagnosis. Subsequent biopsy specimens from the peripheral mucosa containing the whitish enlarged villi showed infiltration of the lymphoma cells forming lymphoid follicles, which led us to the appropriate diagnosis. This case indicates that endoscopists should take biopsy samples from the peripheral mucosa with whitish enlarged villi rather than erosions in the rare instances that erosions appear as the main macroscopic feature of intestinal follicular lymphoma

A rechargeable lithium metal battery operating at intermediate temperatures using molten alkali bis(trifluoromethylsulfonyl)amide mixture as an electrolyte

The physicochemical properties of molten alkali bis(trifluoromethylsulfonyl)amide, MTFSI (M = Li, K, Cs), mixture (xLiTFSI = 0.20, xKTFSI = 0.10, xCsTFSI = 0.70) were studied to develop a new rechargeable lithium battery operating at intermediate temperature (100–180 °C). The viscosity and ionic conductivity of this melt at 150 °C are 87.2 cP and 14.2 mS cm⁻¹, respectively. The cyclic voltammetry revealed that the electrochemical window at 150 °C is as wide as 5.0 V, and that the electrochemical deposition/dissolution of lithium metal occurs at the cathode limit. A Li/MTFSI (M = Li, K, Cs)/LiFePO₄ cell showed an excellent cycle performance at a constant current rate of C/10 at 150 °C; 95% of the initial discharge capacity was maintained after 50 cycles. Except for the initial few cycles, the coulombic efficiencies were approximately 100% for all the cycles, indicating the stabilities of the molten MTFSI mixture and all the electrode materials

Pathophysiological Investigation of the Gastric Surface Mucous Gel Layer of Patients with Helicobacter pylori Infection by Using Immunoassays for Trefoil Factor Family 2 and Gastric Gland Mucous Cell-Type Mucin in Gastric Juice

Background The trefoil factor family (TFF) 2 protein is produced by gastric gland mucous cells (GMCs), and the secreted TFF2 shares a mucosal barrier function with GMC-type mucin. Recently, we presented an enzyme-linked immunosorbent assay (ELISA) method for measurement of GMC-type mucin in the gastric juice. Aims We aimed to develop an ELISA for TFF2 and to assess pathophysiological changes in the gastric surface mucous gel layer (SMGL) of patients with Helicobacter pylori infection. Methods The distribution of TFF2 and GMC-type mucin in the SMGL was immunohistochemically determined. The ELISA for TFF2 was based on a polyclonal goat antibody. Recombinant TFF2 was employed to prepare the calibrators. TFF2 and GMC-type mucin in the gastric juice in healthy individuals (n = 33) and patients with gastritis (n = 37), gastric ulcer (n = 16), and duodenal ulcer (n = 10) were assayed using ELISA. Results TFF2 and GMC-type mucin were immunohistochemically co-localized in the gastric SMGL and GMCs. The TFF2 levels in the patients were significantly higher than those in the healthy individuals. Further, the TFF2 levels in the H. pylori-positive patients were significantly higher than those in the H. pylori-negative patients, and decreased after the eradication of the infection. GMC-type mucin levels showed a tendency similar to that of TFF2 levels. Conclusions The upregulation of TFF2 and GMC-type mucin secretion may reflect the response of the gastric mucosa to H. pylori-induced injuries. TFF2 and GMC-type mucin secreted into the SMGL may protect the gastric mucosa against H. pylori.ArticleDIGESTIVE DISEASES AND SCIENCES. 56(12):3498-3506 (2011)journal articl

Incision and suture to maintain motility

Background : Heineke-Mikulicz (HM) strictureplasty is commonly used to treat short stenoses in Crohn’s disease. However, the degree to which intestinal motility is maintained remains unclear. We compared the peristalsis and transport capacity of the sutured intestines with HM configuration and transverse (TS) and longitudinal (LS) incisions. Methods : The intestinal diameter, intraluminal pressure, and bead transit time of each sutured group were compared with that of the non-treatment (NT) group in the isolated proximal colon of rats. Propulsive contractions were induced using hydroxy-α-sanshool (HAS), a constituent of Japanese pepper. Results : There was no change in the intestinal diameter between HM, TS, and NT groups ; however, it was significantly narrowed at the suture site and its distal side in the LS group. After HAS administration, the intestinal diameter at the suture site in the HM group was higher than that in the LS group. The intraluminal pressure was higher and the transit time was shorter in the HM group compared to those in the LS group. Conclusions : The HM configuration, which widens the incision site and distal diameter and shortens the cut surface of the circular muscle in the longitudinal direction, may help maintain basal and HAS-induced intestinal peristalsis and motility

Senescence marker protein 30 inhibits angiotensin II-induced cardiac hypertrophy and diastolic dysfunction

AbstractBackground and objectiveSenescence marker protein 30 (SMP30) is assumed to behave as an anti-aging factor. Recently, we have demonstrated that deficiency of SMP30 exacerbates angiotensin II-induced cardiac hypertrophy, dysfunction and remodeling, suggesting that SMP30 may have a protective role in the heart. Thus, this study aimed to test the hypothesis that up-regulation of SMP30 inhibits cardiac adverse remodeling in response to angiotensin II.MethodsWe generated transgenic mice with cardiac-specific overexpression of SMP30 gene using α-myosin heavy chain promoter. Transgenic mice and wild-type littermate mice were subjected to continuous angiotensin II infusion (800ng/kg/min).ResultsAfter 14days, heart weight and left ventricular weight were lower in transgenic mice than in wild-type mice, although blood pressure was similarly elevated during angiotensin II infusion. Cardiac hypertrophy and diastolic dysfunction in response to angiotensin II were prevented in transgenic mice compared with wild-type mice. The degree of cardiac fibrosis by angiotensin II was lower in transgenic mice than in wild-type mice. Angiotensin II-induced generation of superoxide and subsequent cellular senescence were attenuated in transgenic mouse hearts compared with wild-type mice.ConclusionsCardiac-specific overexpression of SMP30 inhibited angiotensin II-induced cardiac adverse remodeling. SMP30 has a cardio-protective role with anti-oxidative and anti-aging effects and could be a novel therapeutic target to prevent cardiac hypertrophy and remodeling due to hypertension

Electromagnetic transitions of excited baryons in a deformed oscillator quark model

We study electromagnetic transitions of excited baryons in a deformed oscillator quark model, where baryon excited states are described as rotational bands of deformed intrinsic states. We describe all necessary tools to compute transition amplitudes in multipole basis, which are then related to the commonly used helicity amplitudes. We pay a special attention on the sign of the amplitudes as well as their absolute values by computing the photon and pion couplings simultaneously. We have found that the effect of deformation on the transition amplitudes is rather weak. The difficulty in reproducing the empirical amplitude of the Roper state is discussed.Comment: 29 pages, 3 figures, LaTeX2e, epsf.sty and AMSLaTeX package are required; typos corrected, published versio