Characterization of a retroreflector array for 320-GHz interferometer system in Heliotron J.

A retroreflector array, composed of a cluster of small retroreflectors, is experimentally studied for application to a Michelson-type interferometer system in the fusion plasma experiment. Such a new-type reflector has the potential to be a vital and effective tool at a spatially limited location, such as on the vacuum chamber wall of plasma experimental devices. To investigate the effect of retroreflector array on the reflected beam properties, a tabletop experiment is performed with the retroreflector array composed of 4 mm corner-cube retroreflectors and with a 320-GHz (λ ∼ 0.937 mm) submillimeter wave source. An imaging camera is utilized to measure the submillimeter wave beam profile and is scanned perpendicularly to the beam propagation direction if necessary. The experimental result exhibits a diffraction effect on the reflected beam, resulting in the emergence of discrete peaks on the reflected beam profile, as predicted in the past numerical study; however, the most reflected beam power converges on the one reflected into the incident direction, resulting from a property as a retroreflector. Furthermore, the dependence of the reflected beam on the incident beam angle is characterized while fixing the detector position, and the retroreflection beam intensity is found to vary due to the diffraction effect. Such an undesired variation of beam intensity induced by the diffraction can be suppressed with a focusing lens placed in front of the detector in the practical application to an interferometer.

Measurement of Paα line from pellet ablation cloud in Heliotron J.

The Paα line (1875.13 nm) in the near-infrared (NIR) region was evaluated to apply Stark broadening of the line spectrum to the electron density measurement of the small-pellet ablation cloud in Heliotron J, a medium-sized helical-axis heliotron device. Paα is three-to-four times broader than the visible Hß line (486.13 nm) for the same electron density. Using a portable NIR spectrometer, preliminary proof-of-concept experiments determined the marginal density, below which the broadening was undetectable. The lower detection density limit can be decreased using a narrower entrance slit or a denser grating.

Development and initial results of 320 GHz interferometer system in Heliotron J.

A new 320 GHz solid-state source interferometer is installed in the Heliotron J helical device to explore the physics of high-density plasmas (ne > 2-3 × 1019 m-3, typically) realized with advanced fueling techniques. This interferometry system is of the Michelson type and is based on the heterodyne principle, with two independent solid-state sources that can deliver an output power of up to 50 mW. A high time resolution measurement of <1 µs can be derived by tuning the frequency of one source in the frequency range of 312-324 GHz on the new system, which can realize the fluctuation measurement. We successfully measured the line-averaged electron density in high-density plasma experiments. The measured density agreed well with a microwave interferometer measurement using a different viewing chord, demonstrating that the new system can be used for routine diagnostics of electron density in Heliotron J.

Three-dimensional dynamics of fluctuations appearing during pellet ablation process around a pellet in a fusion plasma experiment.

Understanding pellet ablation physics is crucial to realizing efficient fueling into a high temperature plasma for the steady state operation of ITER and future fusion reactors. Here we report the first observation of the formation of fluctuation structures in the pellet plasmoid during the pellet ablation process by a fast camera in a medium-sized fusion device, Heliotron J. The fluctuation has a normalized fluctuation level of ~ 15% and propagates around the moving pellet across the magnetic field. By comparing the fluctuation structures with the shape of magnetic field lines calculated with the field line tracing code, we successfully reconstruct the spatio-temporal structure of the fluctuations during the pellet ablation process. The fluctuations are located at the locations displaced toroidally from the pellet and propagate in the cross-field direction around the pellet axis along the field line, indicating a three-dimensional behavior and structure of fluctuations. The fluctuation would be driven by a strong inhomogeneity formed around the pellet and invoke the relaxation of the gradient through a cross-field transport induced by the fluctuations, which could affect the pellet ablation and pellet fueling processes. Such fluctuations can be ubiquitously present at the inhomogeneity formed around a pellet in the pellet ablation process in fusion devices.

Protective effect of Lactobacillus casei strain Shirota against lethal infection with multi-drug resistant Salmonella enterica serovar Typhimurium DT104 in mice.

AIMS: The anti-infectious activity of lactobacilli against multi-drug resistant Salmonella enterica serovar Typhimurium DT104 (DT104) was examined in a murine model of an opportunistic antibiotic-induced infection. METHODS AND RESULTS: Explosive intestinal growth and subsequent lethal extra-intestinal translocation after oral infection with DT104 during fosfomycin (FOM) administration was significantly inhibited by continuous oral administration of Lactobacillus casei strain Shirota (LcS), which is naturally resistant to FOM, at a dose of 10(8) colony-forming units per mouse daily to mice. Comparison of the anti-Salmonella activity of several Lactobacillus type strains with natural resistance to FOM revealed that Lactobacillus brevis ATCC 14869(T) , Lactobacillus plantarum ATCC 14917(T) , Lactobacillus reuteri JCM 1112(T) , Lactobacillus rhamnosus ATCC 7469(T) and Lactobacillus salivarius ATCC 11741(T) conferred no activity even when they obtained the high population levels almost similar to those of the effective strains such as LcS, Lact. casei ATCC 334(T) and Lactobacillus zeae ATCC 15820(T) . The increase in concentration of organic acids and maintenance of the lower pH in the intestine because of Lactobacillus colonization were correlated with the anti-infectious activity. Moreover, heat-killed LcS was not protective against the infection, suggesting that the metabolic activity of lactobacilli is important for the anti-infectious activity. CONCLUSION: These results suggest that certain lactobacilli in combination with antibiotics may be useful for prophylaxis against opportunistic intestinal infections by multi-drug resistant pathogens, such as DT104. SIGNIFICANCE AND IMPACT OF THE STUDY: Antibiotics such as FOM disrupt the metabolic activity of the intestinal microbiota that produce organic acids, and that only probiotic strains that are metabolically active in vivo should be selected to prevent intestinal infection when used clinically in combination with certain antibiotics.

Linearized spectrum correlation analysis for thermal helium beam diagnostics.

We introduce a new correlation analysis technique for thermal helium beam (THB) diagnostics. Instead of directly evaluating line ratios from fluctuating time series, we apply arithmetic operations to all available He I lines and construct time series with desired dependencies on the plasma parameters. By cross-correlating those quantities and by evaluating ensemble averages, uncorrelated noise contributions can be removed. Through the synthetic data analysis, we demonstrate that the proposed analysis technique is capable of providing the power spectral densities of meaningful plasma parameters, such as the electron density and the electron temperature, even under low-photon-count conditions. In addition, we have applied this analysis technique to the experimental THB data obtained at the ASDEX Upgrade tokamak and successfully resolved the electron density and temperature fluctuations up to 90 kHz in a reactor relevant high power scenario.

Development of a multi-channel 320 GHz interferometer for high density plasma measurement in Heliotron J.

We report the development of a new interferometer with two stable, high-power, 320 GHz solid-state sources in Heliotron J. A heterodyne Michelson interferometer optical scheme is employed. Two solid-state oscillators are utilized as sources with a fixed frequency at 320 GHz and frequency tunable of 312-324 GHz. Quasi-optical techniques are used for beam transmission. The beam is elongated in the vertical direction with two off-axis parabolic mirrors and injected into the plasma as a sheet beam for the multi-channel measurement (>5 ch.). Passing through the plasma, the beam is reflected at a retroreflector-array installed at the vacuum chamber wall. The retroreflector-array is a bunch of retroreflector structures, which can suppress the beam refraction caused by plasma without much space inside a vacuum chamber unlike a single retroreflector and can facilitate the system design. The source, detectors, and the retroreflector-array are tested to evaluate their basic performance on a tabletop experiment.

Reformation of the Electron Internal Transport Barrier with the Appearance of a Magnetic Island.

When realising future fusion reactors, their stationary burning must be maintained and the heat flux to the divertor must be reduced. This essentially requires a stationary internal transport barrier (ITB) plasma with a fast control system. However, the time scale for determining the position of the foot point of an ITB is not clearly understood even though its understanding is indispensable for fast profile control. In this study, the foot point of the electron ITB (eITB) was observed to be reformed at the vicinity of a magnetic island when the island started to form. In addition, the enhanced confinement region was observed to expand during the eITB formation according to the radial movement of the magnetic island toward the outer region. Compared to the time scales of the local heat transport, the faster time scales of the movement of the eITB foot point immediately after island formation (~0.5 ms) suggest the importance of the magnetic island for plasma profile control to maintain stationary burning.

A component of polysaccharide peptidoglycan complex on Lactobacillus induced an improvement of murine model of inflammatory bowel disease and colitis-associated cancer.

Interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signals play key roles in the pathogenesis of inflammatory bowel disease (IBD). We previously described that both intact cells and a cell wall-derived polysaccharide-peptidoglycan complex (PSPG) in a strain of lactobacillus [Lactobacillus casei Shirota (LcS)] inhibited IL-6 production in lipopolysaccharide (LPS)-stimulated lamina propria mononuclear cells (LPMCs) isolated from murine IBD. Diets with LcS improve murine IBD by suppression of IL-6 synthesis in LPMCs. Moreover, LcS supplementation with fermented milk ameliorates disease activity in patients with active ulcerative colitis. Here, we focused on the specific roles of PSPG in LcS concerning their anti-inflammatory actions. PSPG derived from LcS, and no other strain of lactobacilli, inhibited IL-6 production in LPS-stimulated murine IBD LPMCs. Purified PSPG-I from LcS inhibited IL-6 synthesis in LPS-stimulated murine IBD LPMCs through the inhibition of nuclear factor-kappaB. The anti-IL-6 action of LcS PSPG was abrogated by masking with monoclonal anti-PSPG-I. Furthermore, PSPG-I-negative L. casei strains (PSPG-I-negative mutant LcS: LC(DeltaPSPG-I), L. casei ATCC 334) did not inhibit IL-6 production. Finally, we confirmed the effects of PSPG-I on LcS in the models of both IBD and colitis-associated cancer (CAC). In the IBD model, ingestion of LcS improved ileitis and inhibited activation of IL-6/STAT3 signaling, while ingestion of the LC(DeltaPSPG-I) strain did not. In the CAC model, treatment with LcS, but not the LC(DeltaPSPG-I) strain, showed tumour-suppressive effects with an inhibition of IL-6 production in the colonic mucosa. These results suggested that a specific polysaccharide component in an L. casei strain plays a crucial role in its anti-inflammatory actions in chronic intestinal inflammatory disorders.

Application of portable near-infrared spectrometer to Heliotron J plasma diagnostics.

A simple near-infrared (NIR) spectrometer with a wavelength range of 898-2130 nm has recently been applied to diagnose Heliotron J plasmas. It adopts a symmetrical crossed Czerny-Turner mount equipped with a thermoelectrically cooled 512 channel InGaAs linear sensor. Reciprocal linear dispersion was deduced to 96.37 nm/mm at the center of the detector. External filters can be inserted into the path of the collection optics to reject second-order spectra, as needed. Absolute intensity calibration was performed together with a visible spectrometer using a tungsten halogen lamp, and the effect of the transmittance fringe in the visible region of the applied long-pass filter on the NIR calibration was investigated. The intended application of the NIR spectrometer includes extending the wavelength region of a spectral monitor to less contaminated regions for Heliotron J plasma studies. In preliminary measurements, we observed the Paschen series for the hydrogen pellet injection plasma and two atomic helium lines, i.e., 2S-2P singlet and triplet lines, in helium gas puffing experiments. A continuum spectrum in this regime that is attributable to black-body radiation from hot spots on the plasma-facing components was identified. In addition, this may also be used to monitor background radiation in the YAG-Thomson scattering signals near 1064 nm.

Intestinal microflora are necessary for development of spontaneous adenocarcinoma of the large intestine in T-cell receptor beta chain and p53 double-knockout mice.

This study was conducted to confirm the hypothesis that intestinal microflora are required for the development of adenocarcinoma in the colon of the TCRbeta and p53 double-knockout (TCRbeta-/- p53-/-) mouse. Germ-free TCRbeta-/- p53-/- mice were produced. At 7 weeks of age, the animals were divided into two groups (n = 10/group), and one of these groups was conventionalized. Animals of both groups were subjected to histopathological examination for adenocarcinoma of the colon at 4 months of age. There was no development of adenocarcinoma of the colon among the germ-free mice, whereas in the conventionalized group, adenocarcinomas of the ileocecum and cecum were detected in 70% of animals. These results indicate the usefulness of the TCRbeta-/- p53-/- mouse as a colon cancer animal model that develops spontaneous adenocarcinoma of the colon early in life, and suggest that intestinal microflora play a major role in the development of adenocarcinoma of the colon in this animal model.

Injection barrel with a tapered structure for a low speed and small size cryogenic hydrogen pellet in medium-sized plasma fusion devices.

An injection barrel was designed and fabricated for a small size 0.8 mm cryogenic pellet with a low speed of 200-300 m/s in medium-sized plasma fusion devices. Pellet injection with pneumatic acceleration was examined using a conventional in situ technique. A tapered structure was applied in the downstream side of the injection barrel to satisfy the requirement of pellet speed reduction by expansion of the propellant gas. Shadowgraph and light gate measurements show that the intact pellets have speeds of 260 ± 30 m/s and a typical size of 1.1-1.2 mm. The pellet ablation code based on a neutral gas shielding model shows that the penetration depth of the measured pellet parameters does not cross the plasma center, even in medium-sized plasma devices such as the Heliotron J helical device. The injection barrel with a tapered structure developed in this study is feasible for low speed pellet injection.

Faraday-cup-type lost fast ion detector on Heliotron J.

A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7-42.5 keV (proton) and pitch angle of 90∘-140∘, especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

Development of beam emission spectroscopy for turbulence transport study in Heliotron J.

This paper describes the development study of the beam emission spectroscopy (BES) for the turbulent transport study in Heliotron J. Modification of the sightlines (10 × 4 for edge and 10 × 2 for edge) enables us to obtain 2-dimensional BES imaging. The cooling effect on the reduction in the electrical noise of avalanche photodiode (APD) assembly has been investigated using a refrigerant cooling system. When the temperature of the APD element has set to be -20 °C, the electrical noise can be reduced more than 50%. The measurement error of the phase difference in the case of low signal level has been tested by two light-emitting diode lamps. The APD cooling has an effect to improve the measurement error at the low signal level of APD.

Hepatocyte growth factor in vitreous fluid of patients with proliferative diabetic retinopathy and other retinal disorders.

OBJECTIVE: To determine whether hepatocyte growth factor (HGF) is elevated in the vitreous fluid of patients with proliferative diabetic retinopathy (PDR). RESEARCH DESIGN AND METHODS: Vitreous fluid samples were obtained at the time of vitreoretinal surgery from 73 eyes of PDR patients and from 17 eyes of nondiabetic patients (control subjects) who had macular hole, rhegmatogenous retinal detachment, or epiretinal membrane (9, 4, and 4 eyes, respectively) but no associated proliferative vitreoretinopathy Stages of PDR were classified as active or quiescent. Concentrations of HGF and vascular endothelial growth factor (VEGF) in vitreous fluid were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Intravitreous concentrations of HGF (median [range]) were significantly higher in diabetic patients with PDR (6.00 ng/ml [0.75-22.21) than in control patients (2.86 ng/ml [0.75-5.801). Intravitreous concentrations of VEGF were also higher in diabetic patients with PDR (1.62 ng/ml [0.15-7.91) than in control patients (0.16 ng/ml [0.160.29]). Both VEGF and HGF concentrations were significantly higher in patients with active retinopathy than in those with quiescent retinopathy However, vitreous concentrations of HGF were unrelated to those of VEGE CONCLUSIONS: We found that levels of HGF in vitreous fluid of PDR patients are significantly higher than in nondiabetic patients and that the levels of HGF are elevated in the active PDR stage. This suggests that HGF stimulates or perpetuates neovascularization in PDR.

Lack of association between the Trp64 Arg mutation in the beta 3-adrenergic receptor gene and obesity in Japanese men: a longitudinal analysis.

The beta 3-adrenergic receptor (beta 3AR) is implicated in the regulation of thermogenesis and lipolysis, and it is suggested that the Trp64 Arg mutation in this receptor may contribute to the development of obesity. To examine whether the Trp64 Arg mutation had any effect on body weight during adult life, the beta 3AR genotype was determined in 186 unselected Japanese men, most of whom had records of body weight measured yearly from 25-53 yr of age. Of them, 26 subjects were diagnosed as having noninsulin-dependent diabetes mellitus (NIDDM) and 41 as having impaired glucose tolerance. There were 6 subjects (3%) with homozygous mutation, 67 (36%) with heterozygous mutation, and 113 (61%) with normal allele. Among the 3 genotypes, there were no significant differences in body mass index (BMI) at any age between 25-53 yr and the prevalence of NIDDM at the age of 53 yr. When longitudinal changes in body weight were compared between subjects with and without mutation, the former were less prone to gain weight than the latter. The frequency of the mutant allele was 1) not different among obese (BMI, > 26.4), intermediate (BMI, 22-26.4), and nonobese (BMI, < 22.0) subjects (0.21, 0.22, and 0.26, respectively; P = 0.77); 2) lower in subjects with NIDDM than in those without it, but the difference was insignificant (0.12 vs. 0.23; P = 0.07); and 3) similar between 186 unselected men and another group of 100 patients with NIDDM that were randomly selected for comparison (0.21 vs. 0.23). These results suggest that the beta 3AR is not a major contributing factor to obesity or NIDDM in Japanese men.

Bisphosphonates act on osteoblastic cells and inhibit osteoclast formation in mouse marrow cultures.

We examined the mode of action of bisphosphonates on osteoclastic cell recruitment using mouse marrow cultures with or without osteoblastic cells. Tartrate-resistant acid phosphatase-positive multinucleated cells [TRAP(+)MNC] formed in cultures were determined to be osteoclastic cells. In marrow cultures, TRAP(+) MNC formation in the presence of 10(-8) mol/L 1,25(OH)2D3 was not affected by the addition of 10(-6) mol/L dihydrogen (cycloheptylamino)-methylenebisphosphonate monohydrate (YM175). However, it was inhibited in cocultures of marrow cells with osteoblastic cells. The inhibitory effect was evident throughout the entire culture period. YM175 dose dependently inhibited TRAP(+) MNC formation, and other bisphosphonates--pamidronate and alendronate--also inhibited TRAP(+) MNC formation in the coculture. Similar observations were also made in the coculture of spleen cells with osteoblastic cells. The conditioned media of osteoblastic cells treated with 10(-6) mol/L YM175 inhibited TRAP(+) MNC formation in marrow cultures. The presence of YM175 in methylcellulose cultures affected neither the colony formation of monocyte-macrophage lineage, nor TRAP(+) MNC formation in the succeeding cocultures of recovered cells with osteoblastic cells. These results indicate that YM175 and probably other bisphosphonates as well preferentially inhibit the later stage of osteoclastogenesis through its action on osteoblastic cells. Our findings suggest that part of the inhibitory action by osteoblastic cells in the presence of bisphosphonates is mediated through soluble factor(s).

Westernized food habits and concentrations of serum lipids in the Japanese.

To investigate the association of westernized food habits and concentrations of serum lipids in the Japanese, we studied 1200 healthy Japanese living in Hiroshima prefecture and 1483 ethnic Japanese from Hiroshima prefecture living in the Hawaii Islands and Los Angeles. The nutritional assessments were made by the same dietitians. No major difference was observed in the total energy intake between the Japanese and the Japanese-Americans in both males and females. However, the intake of animal fat and simple carbohydrates (especially fructose) were markedly greater, and that of complex carbohydrates lower, in the Japanese-Americans compared with the Japanese. The mean serum cholesterol (CH), LDL-CH and serum triglyceride (TG) levels were significantly higher in the Japanese-Americans in both sexes. The mean HDL-CH concentration was similar between the two groups in males, but it was approximately 7 mg/dl higher in Japanese-American females. Using the 75 percentile values of CH and TG in the Japanese in Hiroshima, the frequency of WHO types IIa and IIb hyperlipidemia was about twice as high in the Japanese-Americans. These results suggest that westernized food habits in the Japanese include qualitative changes in animal fat, simple carbohydrate and complex carbohydrate diet rather than an increase in the total energy intake. These changes are associated with marked increases in the concentrations of serum CH and TG and increased prevalence of types IIa and IIb hyperlipidemia.

Specific species of intestinal bacteria influence the induction of aberrant crypt foci by 1,2-dimethylhydrazine in rats.

To shed light on the association of intestinal microflora with the development of colon cancer, we studied the modifying effects of intestinal microflora on the occurrence of 1,2-dimethylhydrazine (DMH)-induced colonic aberrant crypt foci (ACF) in germfree (GF), gnotobiotic (GB) and conventionalized (Cvd) rats. In the first part of this study, 10 week old germfree Fischer-344 rats were randomly assigned to three groups and two groups of rats were orally inoculated with mixtures of pure culture of Escherichia coli, Enterococcus faecium, and several strains of Bacteroides and Clostridium species (GB), or feces from conventional rats (Cvd). Inoculated rats were given two weekly i.p. injections of DMH (20 mg/kg body wt) at 13 and 14 weeks of age. Rats were sacrificed 11 or 34 weeks after the last DMH injection for ACF scoring. The total number of ACF, ACF with four or more crypts/focus, and mean number of aberrant crypts per focus (crypt multiplicity) in GB rats sacrificed at week 34 were 168% (P < 0.001), 442% (P < 0.001) and 138% (P < 0.001) of those in GF rats, respectively. On the other hand, the same values in Cvd rats were 42% (P < 0.001), 147% (P = 0.246) and 159% (P < 0.001) of those in GF rats, respectively. Similar results were observed in rats that were sacrificed at week 11. In the second part of this study, the effect of colonization of Bifidobacterium breve on the ACF profiles was examined in GB rats. The number of ACF with four or more crypts/focus and crypt multiplicity in GB plus B. breve rats at week 11 were significantly lower than those of GB rats (P < 0.01, and P < 0.05, respectively), although the former was not statistically significant at week 34. These findings suggest that some intestinal bacteria might behave as promoters and some as anti-promoters in colon carcinogenesis.

Effect of oral administration of Lactobacillus casei on alloxan-induced diabetes in mice.

The effect of Lactobacillus casei (LC) on the onset of alloxan (AXN)-induced diabetes in 7-week-old BALB/c mice were examined. It was observed that the mice given a diet containing 0.1% or 0.05% LC or orally administered LC showed significantly decreased incidence of diabetes induced by intravenous injection of AXN and that the plasma glucose level was slightly lower than that in the control group. The body weight in the LC-treated groups was higher than that in the control group, although the food intake weights were almost the same. Pathological analysis revealed that the AXN-induced disappearance of insulin-secreting beta-cells in the islets of Langerhans was strongly inhibited in the LC-treated groups. It was also shown that the serum nitric oxide level was maintained at a normal level in LC-treated mice, whereas the level in the control group was increased by AXN administration. Taken together, these findings suggest that oral administration of LC to AXN-treated BALB/c mice contributed to the reduction of diabetes and the increase in plasma glucose level.