Risk Evaluation for Coronary Artery Disease in Patients With Impaired Glucose Tolerance After a Successful Coronary Intervention

信州大学博士（医学）・学位論文・平成23年3月31日授与（甲第880号）・堀込充章This is a non-final version of an article published in final form in CLINICAL NUCLEAR MEDICINE. 36(7):546-552 (2011)Purpose: Patients with coronary artery disease (CAD) often have risk factors that may influence endothelial function. The purpose of this study was to evaluate the endothelial function and its association with coronary risk factors after percutaneous coronary intervention (PCI). Materials and Methods: A total of 14 patients with impaired glucose tolerance and CAD underwent positron emission tomography with N-13 ammonia to measure myocardial blood flow (MBF) at rest and during a cold pressor test (CPT), to estimate endothelial function as a percent increase (%increase) of MBF. The results were compared among normal segments (normal), reperfused segments with PCI (PCI), and nonculprit CAD segments without PCI (non-PCI). Correlations between the %increase and major risk factors were also investigated. Results: CPT induced significant increase in MBF in all groups. The %increase of normal, non-PCI, and PCI groups were 33% +/- 22%, 21% +/- 23%, and 26% +/- 23%, respectively. Comparison with risk factors demonstrated significant correlations only in the non-PCI group. Specifically, there were negative correlations between %increase and fasting blood sugar (r = -0.64, P < 0.05), hemoglobin A1c (r = -0.74, P < 0.05), total cholesterol (r = -0.87, P < 0.05), triglyceride (r = -0.71, P < 0.05), and low-density lipoprotein cholesterol (r = -0.92, P < 0.005), respectively. Conclusions: Although impaired glucose tolerance patients with a PCI-treated coronary stenosis showed preserved response to CPT, the %increase negatively correlated with risk factors in the non-PCI segments. Therefore, coronary risk factors may affect CAD lesions in PCI-treated patients.ArticleCLINICAL NUCLEAR MEDICINE. 36(7):546-552 (2011)journal articl

Nonlinear restoring force of spring with stopper for ferroelectric dipole electret-based electrostatic vibration energy harvesters

Previously, we succeeded in developing a new electret [termed a ferroelectric dipole electret (FDE)] having an extremely high electric field using a polarized ferroelectric material. However, the pull-in, in which an oscillator sticks to the FDE under its strong electrostatic force, poses a problem for practical vibration energy harvesters. In this study, we propose use of nonlinear restoring force of a spring with a stopper in order to prevent pull-in for FDE-based vibration energy harvesters. The spring with a stopper was designed using a finite element method (FEM) analysis such that the restoring force of the spring will exceed the electrostatic force of the FDE. The proposed harvester combines the FDE and the spring successfully, and generated electricity without the pull-in. It also showed the highest figure of merit of output power and wide frequency band when compared with other available electret-based vibration energy harvesters. © 2016 Author(s)

High concentrations of omega-3 fatty acids are associated with the development of atrial fibrillation in the Japanese population

The favorable effect of fish oils rich in n-3 polyunsaturated fatty acids (PUFAs) on the development of atrial fibrillation (AF) is controversial. The relationship between the serum concentrations of n-3 PUFAs and the incidence of AF is unclear; therefore, in the present study, we aimed to elucidate this relationship. We evaluated the serum concentrations of n-3 PUFAs in 110 patients with AF, 46 patients with ischemic heart disease (IHD) and no AF, and 36 healthy volunteers. Thirty-six patients had a history of IHD (IHD-AF group) and 74 did not (L-AF group). The eicosapentaenoic acid (EPA) levels in the L-AF group were higher than those in the IHD-AF and control groups (117 +/- A 64, 76 +/- A 30, and 68 +/- A 23 mu g/ml, respectively); the docosahexaenoic acid (DHA) levels showed the same pattern (170 +/- A 50, 127 +/- A 27, and 126 +/- A 35 mu g/ml, respectively). In both the L-AF and IHD-AF groups, the EPA levels in patients with persistent and permanent AF were higher than those in patients with paroxysmal AF (L-AF 131 +/- A 74 vs. 105 +/- A 51 mu g/ml; IHD-AF 82 +/- A 28 vs 70 +/- A 33 mu g/ml). Multivariate analysis showed that cases of AF were associated with higher levels of EPA but not DHA. In this Japanese population study, the EPA and DHA levels in patients with L-AF were higher than those in normal subjects. In particular, the EPA level was associated with the incidence of AF. These findings suggest that an excess of EPA might be a precipitating factor of AF.ArticleHEART AND VESSELS. 28(4):497-504 (2013)journal articl

ATM Modulates the Loading of Recombination Proteins onto a Chromosomal Translocation Breakpoint Hotspot

Chromosome translocations induced by DNA damaging agents, such as ionizing radiation and certain chemotherapies, alter genetic information resulting in malignant transformation. Abrogation or loss of the ataxia-telangiectasia mutated (ATM) protein, a DNA damage signaling regulator, increases the incidence of chromosome translocations. However, how ATM protects cells from chromosome translocations is still unclear. Chromosome translocations involving the MLL gene on 11q23 are the most frequent chromosome abnormalities in secondary leukemias associated with chemotherapy employing etoposide, a topoisomerase II poison. Here we show that ATM deficiency results in the excessive binding of the DNA recombination protein RAD51 at the translocation breakpoint hotspot of 11q23 chromosome translocation after etoposide exposure. Binding of Replication protein A (RPA) and the chromatin remodeler INO80, which facilitate RAD51 loading on damaged DNA, to the hotspot were also increased by ATM deficiency. Thus, in addition to activating DNA damage signaling, ATM may avert chromosome translocations by preventing excessive loading of recombinational repair proteins onto translocation breakpoint hotspots

Nonlinear restoring force of spring with stopper for ferroelectric dipole electret-based electrostatic vibration energy harvesters

Previously, we succeeded in developing a new electret [termed a ferroelectric dipole electret (FDE)] having an extremely high electric field using a polarized ferroelectric material. However, the pull-in, in which an oscillator sticks to the FDE under its strong electrostatic force, poses a problem for practical vibration energy harvesters. In this study, we propose use of nonlinear restoring force of a spring with a stopper in order to prevent pull-in for FDE-based vibration energy harvesters. The spring with a stopper was designed using a finite element method (FEM) analysis such that the restoring force of the spring will exceed the electrostatic force of the FDE. The proposed harvester combines the FDE and the spring successfully, and generated electricity without the pull-in. It also showed the highest figure of merit of output power and wide frequency band when compared with other available electret-based vibration energy harvesters. © 2016 Author(s)

Uncertainty in positioning ion chamber at reference depth for various water phantoms

BackgroundUncertainty in the calibration of high-energy radiation sources is dependent on user and equipment type.AimWe evaluated the uncertainty in the positioning of a cylindrical chamber at a reference depth for reference dosimetry of high-energy photon beams and the resulting uncertainty in the chamber readings for 6- and 10-MV photon beams. The aim was to investigate major contributions to the positioning uncertainty to reduce the uncertainty in calibration for external photon beam radiotherapy.Materials and methodsThe following phantoms were used: DoseView 1D, WP1D, 1D SCANNER, and QWP-07 as one-dimensional (1D) phantoms for a vertical-beam geometry; GRI-7632 as a phantom for a fixed waterproofing sleeve; and PTW type 41023 and QWP-04 as 1D phantoms for a horizontal-beam geometry. The uncertainties were analyzed as per the Guide to the Expression of Uncertainty in Measurement.ResultsThe positioning and resultant uncertainties in chamber readings ranged from 0.22 to 0.35[[ce:hsp sp="0.25"/]]mm and 0.12–0.25%, respectively, among the phantoms (using a coverage factor k[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]1 in both cases). The major contributions to positioning uncertainty are: definition of the origin for phantoms among users for the 1D phantoms for a vertical-beam geometry, water level adjustment among users for the phantom for a fixed waterproofing sleeve, phantom window deformation, and non-water material of the window for the 1D phantoms for a horizontal-beam geometry.ConclusionThe positioning and resultant uncertainties in chamber readings exhibited minor differences among the seven phantoms. The major components of these uncertainties differed among the phantom types investigated

Pulsed laser deposition of air-sensitive hydride epitaxial thin films: LiH

We report on the epitaxial thin film growth of an air-sensitive hydride, lithium hydride (LiH), using pulsed laser deposition (PLD). We first synthesized a dense LiH target, which is key for PLD growth of high-quality hydride films. Then, we obtained epitaxial thin films of [100]-oriented LiH on a MgO(100) substrate at 250 °C under a hydrogen pressure of 1.3 × 10−2 Pa. Atomic force microscopy revealed that the film demonstrates a Stranski-Krastanov growth mode and that the film with a thickness of ∼10 nm has a good surface flatness, with root-mean-square roughness RRMS of ∼0.4 nm

Investigation of Silicon Core-Based Fiber Bragg Grating for Simultaneous Detection of Temperature and Refractive Index

In this article, we theoretically designed and simulated a silicon core fiber for the simultaneous detection of temperature and refractive index. We first discussed the parameters of the silicon core fiber for near single-mode operation. Second, we designed and simulated a silicon core-based fiber Bragg grating and applied it for simultaneous sensing of temperature and environmental refractive index. The sensitivities for the temperature and refractive index were 80.5 pm/°C and 208.76 dB/RIU, respectively, within a temperature range of 0 to 50 °C and a refractive index range of 1.0 to 1.4. The proposed fiber sensor head can provide a method with simple structure and high sensitivity for various sensing targets