1,124 research outputs found

    Extended Superconformal Algebras and Free Field Realizations from Hamiltonian Reduction

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    We develop the method of the hamiltonian reduction of affine Lie superalgebras to obtain explicit and general expressions both for the classical and the quantum extended superconformal algebras. By performing the gauge transformation which connects the diagonal gauge with the Drinfeld-Sokolov gauge and considering the quantum corrections, we get generic expressions for the classical and quantum free field realizations of the algebras.Comment: 10 pages, NBI-HE-93-1

    Change of glaciers in Spitsbergen Island since 1933 observed with surface photographs

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    Change of several glaciers in Spitsbergen Island was investigated using surface photographs taken in 1933 and afterward. All glaciers investigated decreased their thickness and area at their terminal parts in the period from 1933 to 2004

    Increased Circulating Malondialdehyde-Modified Low-Density Lipoprotein Level Is Associated with High-Risk Plaque in Coronary Computed Tomography Angiography in Patients Receiving Statin Therapy

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    Objective: To evaluate the association of serum malondialdehyde low-density lipoprotein (MDA-LDL), an oxidatively modified LDL, with the prevalence of high-risk plaques (HRP) determined with coronary computed tomography angiography (CTA) in statin-treated patients. Methods: This study was a single-center retrospective cohort comprising 268 patients (mean age 67 years, 58% men) with statin therapy and who underwent coronary CTA for suspected stable coronary artery disease. Patients were classified into two groups according to median MDA-LDL level or median LDL-C level. Coronary CTA-verified HRP was defined when two or more characteristics, including positive remodeling, low-density plaques, and spotty calcification, were present. Results: Patients with HRP had higher MDA-LDL (p = 0.011), but not LDL-C (p = 0.867) than those without HRP. High MDA-LDL was independently associated with HRP (odds ratio 1.883, 95% confidential interval 1.082-3.279) after adjustment for traditional risk factors. Regarding incremental value of MDA-LDL for predicting CTA-verified HRP, addition of serum MDA-LDL levels to the baseline model significantly increased global chi-square score from 26.1 to 32.8 (p = 0.010). Conclusions: A high serum MDA-LDL level is an independent predictor of CTA-verified HRP, which can lead to cardiovascular events in statin-treated patients

    Differential scanning fluorimetric analysis of the amino-acid binding to taste receptor using a model receptor protein, the ligand-binding domain of fish T1r2a/T1r3

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    Taste receptor type 1 (T1r) is responsible for the perception of essential nutrients, such as sugars and amino acids, and evoking sweet and umami (savory) taste sensations. T1r receptors recognize many of the taste substances at their extracellular ligand-binding domains (LBDs). In order to detect a wide array of taste substances in the environment, T1r receptors often possess broad ligand specificities. However, the entire ranges of chemical spaces and their binding characteristics to any T1rLBDs have not been extensively analyzed. In this study, we exploited the differential scanning fluorimetry (DSF) to medaka T1r2a/T1r3LBD, a current sole T1rLBD heterodimer amenable for recombinant preparation, and analyzed their thermal stabilization by adding various amino acids. The assay showed that the agonist amino acids induced thermal stabilization and shifted the melting temperatures (T-m) of the protein. An agreement between the DSF results and the previous biophysical assay was observed, suggesting that DSF can detect ligand binding at the orthostericbinding site in T1r2a/T1r3LBD. The assay further demonstrated that most of the tested Lamino acids, but no D-amino acid, induced T-m shifts of T1r2a/T1r3LBD, indicating the broad L-amino acid specificities of the proteins probably with several different manners of recognition. The T-m shifts by each amino acid also showed a fair correlation with the responses exhibited by the full-length receptor, verifying the broad amino-acid binding profiles at the orthosteric site in LBD observed by DSF

    Factors Related to Positive Feelings of Caregivers Who Provide Home-Based Long-Term Care for Their Family Members in Japan

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    Background. The objective is to elucidate the factors related to the positive feelings of family caregivers who are engaged in home-based elderly care. Methods. The study utilized the data of a cross-sectional citywide survey in Japan. The survey was conducted with 1,821 subjects and the final analysis was performed on 435 subjects. Questions for recipients such as those on their care levels, causes of care, whereas the primary caregivers were asked about whether they had positive feelings toward caregiving, and whether their opinion was reflected in care policies. Results. The factors s that showed a positive association with positive feelings were “the caregiver’s opinion is reflected in care policies” (OR: 5.05, 95% CI: 2.60–9.87) and “the caregiver is in good health condition” (OR: 2.02, 95% CI: 1.02–3.93). The factors that showed a negative association were “the caregiver is a daughter-in-law of the care recipient” (OR: 0.42, 95% CI: 0.21–0.82) and “the care recipient is an elderly person with cognitive impairment” (OR: 0.36, 95% CI: 0.18–0.70). Conclusions. The study suggests the necessity of providing support for caregivers in terms of empowerment and health management. Furthermore, they suggest that special attention should be paid to caregivers at risk of being unable to sustain positive feelings toward caregiving

    Light-Induced Degradation Mechanism in Poly(3-hexylthiophene)/Fullerene Blend Solar Cells

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    The mechanism of light-induced degradation in organic solar cells based on regioregular poly(3-hexylthiophene) and indene-C60 bisadduct is studied by transient absorption (TA) and electron spin resonance (ESR) measurements. After 45 h light exposure under simulated solar illumination at 100 mW cm-2, the short-circuit current density, open-circuit voltage, and fill factor are all degraded by about 20%-30% relative to the initial photovoltaic parameters. For the assignment of limiting conversion processes in the degraded solar cells, exciton diffusion into a donor/acceptor interface, charge transfer at the interface, charge dissociation into free charge carriers, and charge collection to each electrode are observed before and after the light exposure by the TA measurement. As a result, it is found that the charge collection deteriorates after the light exposure because of light-induced charge trap formation in the bulk of the active layer. The origin of charge traps is further discussed on the basis of ESR measurements and density functional theory calculation

    Association of Oxidized Low-Density Lipoprotein in Nonalcoholic Fatty Liver Disease with High-Risk Plaque on Coronary Computed Tomography Angiography: A Matched Case-Control Study

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    Nonalcoholic fatty liver disease (NAFLD) is a risk factor for the development of atherosclerotic cardiovascular diseases (CVDs), and oxidative stress has been proposed as a shared pathophysiological condition. This study examined whether oxidized low-density lipoprotein (LDL) is involved in the underlying mechanism that links coronary atherosclerosis and NAFLD. This study included 631 patients who underwent coronary computed tomography angiography (CTA) for suspected coronary artery disease. NAFLD was defined on CT images as a liver-to-spleen attenuation ratio of <1.0. Serum-malondialdehyde-modified LDL (MDA-LDL) and coronary CTA findings were analyzed in a propensity-score-matched cohort of patients with NAFLD (n = 150) and those without NAFLD (n = 150). This study analyzed 300 patients (median age, 65 years; 64% men). Patients with NAFLD had higher MDA-LDL levels and a greater presence of CTA-verified high-risk plaques than those without NAFLD. In the multivariate linear regression analysis, MDA-LDL was independently associated with NAFLD (beta = 11.337, p = 0.005) and high-risk plaques (beta = 12.487, p = 0.007). Increased MDA-LDL may be a mediator between NAFLD and high-risk coronary plaque on coronary CTA. Increased oxidative stress in NAFLD, as assessed using MDA-LDL, may be involved in the development of CVDs

    ヒト角化上皮細胞における5-FU誘発性酸化ストレスおよび炎症応答に対するresveratrolの保護効果

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    Although 5-fluorouracil (5-FU) is currently used as an anti-cancer chemotherapy, adverse effects such as oral mucositis potentially limit its clinical application. Additionally, the prevention of 5-FU-induced side effects are scarce. Resveratrol is known to decrease oxidative damage and inflammation. In this study, we examined the protective effects of resveratrol on 5-FU-induced oxidative stress and inflammatory responses in normal human keratinocytes (HaCaT cell) as in vitro oral mucositis model. HaCaT cells were exposed to 5-FU and simultaneously treated with resveratrol. The effects of resveratrol on 5-FU-induced cytotoxicity were evaluated using cell viability assay. The production of reactive oxygen species (ROS) was measured using a fluorescence spectrophotometer. The effects of resveratrol on nuclear factor erythroid 2-related factor 2 (Nrf2), silent information regulator transcript-1 (SIRT-1), and nuclear factor kappa B (NF-κB) signaling and inflammatory cytokine expression were examined. Resveratrol suppressed 5-FU-induced overproduction of ROS by upregulating anti-oxidant defense genes through Nrf2 activation and SIRT-1 expression. Concerning inflammatory responses, resveratrol suppressed the 5-FU-induced expression of pro-inflammatory cytokines via NF-κB nuclear translocation. Conversely, N-acetylcysteine reduced ROS levels without affecting the expression of pro-inflammatory cytokines. Resveratrol might be useful for preventing 5-FU-induced adverse effects by activating anti-oxidant and anti-inflammatory responses

    Association of perivascular fat attenuation on computed tomography and heart failure with preserved ejection fraction

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    Aims Heart failure with a preserved ejection fraction (HFpEF) is associated with chronic inflammation. We aimed to investigate the association between pericoronary adipose tissue attenuation (PCATA) on coronary computed tomography angiography as a novel noninvasive marker of pericoronary inflammation and the presence of HFpEF. Methods and results This retrospective study included 607 outpatients (median age, 65 years; 50% male) who underwent both echocardiography and coronary computed tomography angiography. Patients with obstructive coronary artery disease were excluded from this study. PCATA was compared between patients with and without HFpEF, which was diagnosed according to the Heart Failure Association (HFA)-PEFF score. PCATA was assessed at the proximal 40-mm segments of all three major coronary arteries on coronary computed tomography angiography. Patients with HFpEF had higher PCATA in all coronary arteries compared to the control participants: left anterior descending artery (LAD), -65.2 +/- 6.9 Hounsfield units (HU) vs. -68.1 +/- 6.7 HU; left circumflex artery (LCX), -62.7 +/- 6.8 HU vs. -65.4 +/- 6.6 HU; and right coronary artery (RCA), -63.6 +/- 8.5 HU vs. -65.5 +/- 7.7 HU (P Conclusions High PCATA score was significantly associated with the presence of HFpEF. Our results suggest that inflammation in the pericoronary artery adipose tissue is one of the underlying mechanisms of HFpEF
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