Activity of Hokkaido University Neutron Source, HUNS

AbstractHokkaido University neutron source, HUNS was completed in 1973, and has been used actively for developments of moderators, neutron instruments, neutron devices and new methods for 40 years although its power is not so high. Recently, a pulsed neutron imaging method has been developed and a new type of small angle neutron scattering method has been also developed. The pulsed neutron imaging is a unique method that can give the physical quantities such as crystallographic quantities of materials over wide area of the real space. So far, the small angle neutron scattering (SANS) is considered to be impossible at a neutron source with a power of HUNS. However, mini focusing SANS (mfSANS) was developed and proved to be useful. Here, we present the present activities on the pulsed neutron imaging and mfSANS at HUNS

Effects of calcium channel blockers on glucose tolerance, inflammatory state, and circulating progenitor cells in non-diabetic patients with essential hypertension: a comparative study between Azelnidipine and amlodipine on glucose tolerance and endothelial function - a crossover trial (AGENT)

<p>Abstract</p> <p>Background</p> <p>Hypertension is associated with impaired glucose tolerance and insulin resistance. Medical treatment that interferes with various steps in the renin-angiotensin system improves glucose tolerance and insulin resistance. However, it remains unclear if long-acting calcium channel blockers (CCBs) such as azelnidipine and amlodipine affect glucose tolerance and insulin resistance in clinical practice.</p> <p>Methods</p> <p>Seventeen non-diabetic patients with essential hypertension who had controlled blood pressure levels using amlodipine (5 mg/day) were enrolled in this study. After randomization, either azelnidipine (16 mg/day) or amlodipine (5 mg/day) was administered in a crossover design for 12-weeks. At baseline and the end of each CCB therapy, samples of blood and urine were collected and 75 g oral glucose tolerance test (OGTT) was performed. In addition, hematopoietic progenitor cells (HPCs) were measured at each point by flow cytometry and endothelial functions were measured by fingertip pulse amplitude tonometry using EndoPAT.</p> <p>Results</p> <p>Although blood pressure levels were identical after each CCB treatment, the heart rate significantly decreased after azelnidipine administration than that after amlodipine administration (<it>P </it>< 0.005). Compared with amlodipine administration, azelnidipine significantly decreased levels of glucose and insulin 120 min after the 75 g OGTT (both <it>P </it>< 0.05). Serum levels of high-sensitivity C-reactive protein (<it>P </it>= 0.067) and interleukin-6 (<it>P </it>= 0.035) were decreased. Although endothelial functions were not different between the two medication groups, the number of circulating HPCs was significantly increased after azelnidipine administration (<it>P </it>= 0.016).</p> <p>Conclusions</p> <p>These results suggest that azelnidipine treatment may have beneficial effects on glucose tolerance, insulin sensitivity, the inflammatory state, and number of circulating progenitor cells in non-diabetic patients with essential hypertension.</p

Enhanced production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in very long chain saturated fatty acid-accumulated macrophages

<p>Abstract</p> <p>Background</p> <p>Deterioration of peroxisomal β-oxidation activity causes an accumulation of very long chain saturated fatty acids (VLCSFA) in various organs. We have recently reported that the levels of VLCSFA in the plasma and/or membranes of blood cells were significantly higher in patients with metabolic syndrome and in patients with coronary artery disease than the controls. The aim of the present study is to investigate the effect of VLCSFA accumulation on inflammatory and oxidative responses in VLCSFA-accumulated macrophages derived from X-linked adrenoleukodystrophy (X-ALD) protein (ALDP)-deficient mice.</p> <p>Results</p> <p>Elevated levels of VLCSFA were confirmed in macrophages from ALDP-deficient mice. The levels of nitric oxide (NO) production stimulated by lipopolysaccharide (LPS) and interferon-γ (IFN-γ), intracellular reactive oxygen species (ROS), and pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interluekin-6 (IL-6), and interleukin-12p70 (IL-12p70), were significantly higher in macrophages from ALDP-deficient mice than in those from wild-type mice. The inducible NO synthase (iNOS) mRNA expression also showed an increase in macrophages from ALDP-deficient mice.</p> <p>Conclusion</p> <p>These results suggested that VLCSFA accumulation in macrophages may contribute to the pathogenesis of inflammatory diseases through the enhancement of inflammatory and oxidative responses.</p

Study on phase transition of Pb-Bi eutectic alloy by neutron transmission spectroscopy

LBE (Lead Bismuth Eutectic), which is a candidate for spallation targets, has some problems. One of them is expansion after solidification, which may bring about serious damage of an LBE loop. Two solid phases of β-phase (inter-metallic compound) and γ-phase (solid solution of Pb in Bi) appear in LBE, and it was reported that an increase of the γ-phase observed by X-ray corresponds to the volume expansion of LBE. We performed neutron spectroscopic transmission experiments using a pulsed neutron source in order to observe crystal transformation depending on the position and time for slow and rapid cooling LBE samples. It was found that the crystal structure of the slow cooling LBE varied depending on position while it was rather homogeneous for the rapid cooling sample. The re-crystallization of the γ-phase was more clearly observed for the rapid cooling sample than the slow one. We were able to obtain information of re-crystallization over the whole volume of the samples

Pulsed neutron spectroscopic imaging for crystallographic texture and microstructure

A time-of-flight (TOF) spectroscopic neutron imaging at a pulsed neutron source is expected to be a new material analysis tool because this method can non-destructively investigate the spatial dependence of the crystallographic and metallographic information in a bulk material. For quantitative evaluation of such information, a spectral analysis code for the transmission data is necessary. Therefore, we have developed a Rietveld-like analysis code, RITS. Furthermore, we have applied the RITS code to evaluation of the position dependence of the crystal orientation anisotropy, the preferred orientation and the crystallite size of a welded α-iron plate, and we have successfully obtained the information on the texture and the microstructure. However, the reliability of the values given by the RITS code has not been evaluated yet in detail. For this reason, we compared the parameters provided by the RITS code with the parameters obtained by the neutron TOF powder diffractometry and its Rietveld analysis. Both the RITS code and the Rietveld analysis software indicated values close to each other, but there were systematic differences on the preferred orientation and the crystallite size

Angular distributions of absorbed dose of Bremsstrahlung and secondary electrons induced by 18-, 28- and 38-MeV electron beams in thick targets

Angular distributions of absorbed dose of Bremsstrahlung photons and secondary electrons at a wide range of emission angles from 0 to 135, were experimentally obtained using an ion chamber with a 0.6 cm(3) air volume covered with or without a build-up cap. The Bremsstrahlung photons and electrons were produced by 18-, 28- and 38-MeV electron beams bombarding tungsten, copper, aluminium and carbon targets. The absorbed doses were also calculated from simulated photon and electron energy spectra by multiplying simulated response functions of the ion chambers, simulated with the MCNPX code. Calculated-to-experimental (C/E) dose ratios obtained are from 0.70 to 1.57 for high-Z targets of W and Cu, from 15 to 135 and the C/E range from 0.6 to 1.4 at 0; however, the values of C/E for low-Z targets of Al and C are from 0.5 to 1.8 from 0 to 135. Angular distributions at the forward angles decrease with increasing angles; on the other hand, the angular distributions at the backward angles depend on the target species. The dependences of absorbed doses on electron energy and target thickness were compared between the measured and simulated results. The attenuation profiles of absorbed doses of Bremsstrahlung beams at 0, 30 and 135 were also measured