Cytokinesis-block micronucleus (CBMN) assay is a convenient and easy method of radiation biodosimetry that uses peripheral blood (PB) cells. However, for micronuclei (MN) frequency induced by ...ionising radiation, a dose-response relationship in abnormal condition, such as in cancer patients, has not been assessed. To clarify the difference between the dose-response curve generated by the CBMN assay in conditions when thyroid hormone levels were normal and during thyroid hormone withdrawal (THW) prior to (131)I treatment, 12 thyroid cancer patients who underwent thyroidectomy were studied. The collected PB mononuclear cells were exposed to 0.5-3.0 Gy X-ray irradiation. Under normal conditions, dose dependency and independency of MN frequency were observed in 92 % and 8 %, respectively. In contrast, during THW, the number of patients who showed dose independency significantly increased to 42 % in comparison with control. Furthermore, a higher concentration of serum thyroglobulin in dose-independent patients was observed. These results suggest that MN frequency in cytogenetic dosimetry is affected by thyroid hormones.
Here we examined whether the Matsuda-DeFronzo insulin sensitivity index (ISI-M) is more efficient than the homeostasis model assessment of insulin resistance (HOMA-IR) for assessing risk of ...hypertension. Cross-sectional and longitudinal analyses were conducted using normotensive subjects who were selected among 1399 subjects in the Tanno-Sobetsu cohort. In the cross-sectional analysis (n=740), blood pressure (BP) level was correlated with HOMA-IR and with ISI-M, but correlation coefficients indicate a tighter correlation with ISI-M. Multiple linear regression analysis adjusted by age, sex, body mass index (BMI) and serum triglyceride level (TG) showed contribution of ISI-M and fasting plasma glucose, but not of HOMA-IR. In the longitudinal analysis (n=607), 241 subjects (39.7%) developed hypertension during a 10-year follow-up period, and multiple logistic regression indicated that age, TG, systolic BP and ISI-M, but not HOMA-IR, were associated with development of hypertension. In subjects <60 years old, odds ratio of new-onset hypertension was higher in the low ISI-M group (ISI-M, less than the median) than in the high ISI-M group for any tertile of BMI. In conclusion, ISI-M is a better predictor of hypertension than is HOMA-IR. Non-hepatic IR may be a determinant, which is independent of TG, BP level and BMI, of the development of hypertension.
The dynamic stability of a liquid in a hemispherical tank covered with a plane diaphragm under vertical excitation was studied both theoretically and experimentally. In the analysis, the liquid was ...assumed to be incompressible, non-viscous, and irrotational, and the plane diaphragm was a clamped circular membrane. The equation of motion was derived using the Galerkin method. The central frequency and width parameter of the instability region, in which parametric vibration occurred, were obtained using the Hsu’s method. In the experiment, two silicon test membranes with a diameter of 500 mm and thicknesses of 0.22 mm and 0.34 mm, were used as test plane diaphragms. Each test membrane was uniformly tensioned in the radial direction at ten points that were uniformly spaced along the circumference of the edge of the membrane. The central frequency and instability regions were measured by vertically exciting the test tank and measuring their responses using a laser Doppler vibrometer. The effect of diaphragm tension on parametric instability regions is presented in this paper. A comparison of the instability region between the experimental and the theoretical results showed that they were in good agreement, including in the case of a free surface.
•Effect of tension of diaphragm on the dynamic stability of hemi-spherical tank was clarified.•Instability regions were compared with experiment and analysis.•Two test membranes with different thickness were used in the experiment.•Mathieu equation was derived and the instability regions were determined by Hsu’s method.
We demonstrate that globular cluster G1 could have been formed by tidal interaction between M 31 and a nucleated dwarf galaxy (dE,N). Our fully self-consistent numerical simulations show that during ...tidal interaction between M 31 and G1's progenitor dE,N with $M_{B} \sim -15$ mag and its nucleus mass of ~107 $M_{\odot}$, the dark matter and the outer stellar envelope of the dE,N are nearly completely stripped whereas the nucleus can survive the tidal stripping because of its initially compact nature. The naked nucleus (i.e., G1) has orbital properties similar to those of its progenitor dE,N. The stripped stars form a metal-poor (Fe/H ~ -1) stellar halo around M 31 and its structure and kinematics depend strongly on the initial orbit of G1's progenitor dE,N. We suggest that the observed large projected distance of G1 from M 31 (~40 kpc) can give some strong constraints on the central density of the dark matter halo of dE,N. We discuss these results in the context of substructures of M 31's stellar halo recently revealed by Ferguson et al. (CITE).
In this study, to simulate liquid sloshing in a spacecraft fuel tank, the effect of tension of a plane diaphragm on the hydroelastic coupled vibration of the liquid in a hemispherical tank was ...investigated both analytically and experimentally. In the theoretical analysis, the liquid was assumed to be incompressible, non-viscous, and irrotational, and the plane diaphragm corresponded to a clamped circular membrane. The influence of tension of the diaphragm on the natural frequency was investigated. In addition, its natural frequencies and vibration modes were compared with those of a liquid in a cylindrical tank. The comparison revealed that the natural vibration characteristics of a liquid in a hemispherical tank approximate those of a liquid with the same volume in a cylindrical tank. In the experiment, two silicon test membranes with diameters of 500 mm, one 0.22 mm thick and the other 0.34 mm thick, were used as plane diaphragms. Each test membrane was uniformly tensioned in the radial direction at ten points that were uniformly spaced along the circumference of the edge of the membrane. The natural frequencies were measured by tapping the test membranes with a finger and conducting an FFT analysis of the response. The vibration modes were measured by exciting the membranes acoustically and measuring their responses using a scanning laser Doppler vibrometer. A comparison between the experimental and theoretical results showed that they were in good agreement, even in the case of an empty tank. This demonstrates the validity of the theoretical analysis and accuracy of the experimental results.
•Investigated effect of tension on hydroelastic coupled vibration of liquid in tank covered with plane diaphragm from both theoretically and experimentally.•Two test silicon membranes used as plane diaphragms were uniformly tensioned.•Sloshing characteristic of liquid in a hemispherical tank covered with plane diaphragm can be approximated with that of liquid having the same volume in a cylindrical tank.•Experimental results and theoretical results showed good agreement.
Augmented oxidative stress induced by hyperglycaemia possibly contributes to the pathogenesis of diabetic complications. Oxidative stress is known to increase the conversion of deoxyguanosine to ...8-oxo, 2'-deoxyguanosine in DNA. To investigate the possible contribution of oxidative DNA damage to the pathogenesis of diabetic complications, we measured the content of 8-oxo, 2'-deoxyguanosine in the urine and the blood mononuclear cells of Type II (non-insulin-dependent) diabetic patients.
We studied 53 Type II diabetic patients and 39 age-matched healthy control subjects. We assayed 8-oxo, 2'-deoxyguanosine by HPLC-electrochemical detection method.
The content of 8-oxo, 2'-deoxyguanosine in the urine and the mononuclear cells of the Type II diabetic patients was much higher than that of the control subjects. Urinary 8-oxo, 2'-deoxyguanosine excretion and the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells from the diabetic patients with complications were higher than those from the diabetic patients without complications. Urinary excretion of 8-oxo, 2'-deoxyguanosine was significantly correlated with the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells. The 8-oxo, 2'-deoxyguanosine content in the urine and mononuclear cells was correlated with the haemoglobin A1c value.
This is the first report of a direct association between oxidative DNA damage and the complications of diabetes. The augmented oxidative DNA damage in diabetes is speculated to contribute to the pathogenesis of diabetic complications.
Self-healing coatings with capsules containing healing agents have been developed for the corrosion protection of metal. In this paper, polyurethane capsules were synthesized under different ...conditions to examine the size and shape of capsules, and self-healing ability of coatings with capsules dispersed was examined after damaging the coated layer by scratching with a cutter blade. The size and shape of capsules depended on the concentration of chlorobenzene in cyclohexanone used as a solvent of prepolymer solution. The capsule formed with 70 % of chlorobenzene gave a self-healing capability to the coated layer by releasing the healing agent after damaging. The amount of glycerol added for the formation of the polyurethane capsule shell affected the self-healing ability of the coated layer. The coating with the capsule formed with small amounts of glycerol showed a high healing ability, while, with large amounts of glycerol, the self-healing ability was relatively low.
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