This study investigates the influence of the condensation coefficient of vapour on the collapse of a bubble composed of condensable gas (vapour) and non-condensable gas (NC gas). We simulated vapour and NC gas flow inside a bubble based on the molecular gas dynamics analysis in order to replicate the phase change (viz., evaporation and condensation) precisely, by changing the initial number density ratio of the NC gas and vapour, the initial bubble radius and the value of the condensation coefficient. The results show that the motion of the bubble is unaffected by the value of the condensation coefficient when that value is larger than approximately 0.4. We also discuss NC gas drift at the bubble wall during the final stage of the bubble collapse and its influence on the condensation coefficient. We conclude that vapour molecules can behave as NC gas molecules when the bubble collapses, owing to the large concentration of NC gas molecules at the gas–liquid interface. That is, the condensation coefficient reaches almost zero when the bubble collapses violently.

Recently, many superflares on solar-type stars were discovered as white-light flares (WLFs). A correlation between the energies (E) and durations (t) of superflares is derived as t∝E0.39, and this can be theoretically explained by magnetic reconnection (t∝E1/3). In this study, we carried out a statistical research on 50 solar WLFs with SDO/HMI to examine the t-E relation. As a result, the t-E relation on solar WLFs (t∝E0.38) is quite similar stellar superflares, but the durations of stellar superflares are much shorter than those extrapolated from solar WLFs. We present the following two interpretations; (1) in solar flares, the cooling timescale of WL emission may be longer than the reconnection one, and the decay time can be determined by the cooling timescale; (2) the distribution can be understood by applying a scaling law t∝E1/3B−5/3 derived from the magnetic reconnection theory.

We present the water column profiles (surface to 2000 m depth) for dissolved inorganic radiocarbon (14CDIC) from 2 stations in the Kuroshio region including the Kuroshio large meander (LM) of 2004–2005. Surprisingly, the Δ14CDIC value varied up to 125‰ in the intermediate layer, especially near 600 m depth. In addition, the Δ14CDIC value was approximately − 150‰ at 200 m depth at the northern station of Kuroshio in August 2005. This value is ∼100‰ less than other Δ14CDIC values for the same depth. In comparison, the Δ14CDIC water column profiles for the southern station of Kuroshio and GEOSECS station 224 decrease down to 600 m depth and were similar below 600 m depth. Our results suggest that strong upwelling associated with the Kuroshio LM has a powerful influence on the Δ14CDIC water column profiles in the study region.

Our preliminary clinical trial showed that consumption of cooked rice of a Japanese common cultivar Yukihikari improved atopic dermatitis associated with a suspected rice allergy, although the underlying mechanisms remain unclear. We hypothesised that the ameliorating effect of Yukihikari on atopic dermatitis is associated with the gut microbiota. BALB/c mice were fed a synthetic diet supplemented with uncooked and polished white rice powder prepared from one of four different cultivars: Yukihikari, rice A (common rice), rice B (brewery rice) and rice C (waxy rice). Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments showed that the composition of faecal microbiota was different between mice fed Yukihikari and those fed rice A. Analysis of the 16S rRNA clone library and species-specific real-time PCR showed that the abundance of Akkermansia muciniphila, a mucin degrader, tended to be lower in mice fed Yukihikari. The incidence of allergic diarrhoea induced by oral administration of ovalbumin in systemically immunised mice was lower in mice fed Yukihikari, albeit with no difference in serum antibodies specific to ovalbumin. In a separate experiment, serum antibody levels specific to orally administered ovalbumin were lower in mice fed Yukihikari. Additionally, the translocation of horseradish peroxidase in isolated segments of ileum and colon tended to be lower in mice fed Yukihikari, suggesting a reduction in gut permeability in mice fed Yukihikari. These data indicate that changes in the gut microbiota of mice fed Yukihikari could be advantageous in the prevention of food allergy.

Grain boundary character distribution-optimized (GBCD) Type 316 corresponding austenitic stainless steel and its cold-worked ones (GBCD+CW) are one of prospective nuclear materials to be considered for next generation energy systems. These steels were thermally-aged at 973 K for 1 and 100 h and were examined by transmission electron microscopy (TEM) to evaluate microstructural stability during high temperature exposure. TEM results revealed that microstructures of both specimens prior to ageing contained step-wise boundaries which is composed of coincidence site lattice (CSL) and random grain boundaries and also that the GBCD+CW specimens had dislocation cells and networks as well as deformation twins whereas as the GBCD one possessed few dislocations. After thermal ageing, the precipitates formed on not only random grain boundaries but also dislocations, contributing to prevent significant microstructural change occurring such as recrystallization and dislocation recovery.

Cu-In-S nanocrystals were developed as a low toxic fluorescent. The stoichiometric CuInS2 nanocrystals were synthesized facilely by heating a solution of metal complexes. The fluorescence would be originated from the crystal defect. We intentionally introduced the crystal defects related to Cu deficiency in nanocrystal with the prospect that the fluorescence intensity would be increased. The nanocrystals have many defects without phase separation as observed in bulk material. Consequently, the fluorescence quantum yield achieved to c.a. 6%. Moreover, the fluorescence quantum yield was increased up to 15% by the ZnS-coating.

CuInS2 (CIS) fluorescent nanocrystals (NCs) were obtained by heating organic metal complex. The photoluminescence (PL) originated from the donor-acceptor, and the quantum yield (QY) was achieved at 6%. Furthermore, we doped some metal ions (Zn2+, Cd2+ or Ag+) by the post heat-treatment in the organic coordinating solvent in order to tune the band gap of NCs. By this post treatment, the alteration of NCs structure was suggested, such as changing into an alloying and composite structure. In Zn-doping, the PL wavelength was widely tuned from 535 to 650 nm by alloying between CIS and ZnS. Moreover, PL intensity was increased with these structure alterations. In particular, the materials doped with Zn or Cd achieved respective QY of 25% and 40%.

The current epidemic of diabetes likely reflects marked changes in environmental factors, although genetic susceptibility plays a powerful role in the occurrence of diabetes in certain populations. We investigated whether long-term sucrose-drinking causes hyperglycaemia in male Wistar-Imamichi littermates (n 32), which are not genetically susceptible to diabetes or obesity. Each litter was divided equivalently into two groups, the sucrose group and the control group. The sucrose group received 300 g/l sucrose water and the control group received regular water until 42 weeks of age. Rats were weighed every 1 or 2 weeks. Oral glucose tolerance tests were performed at 28 and 36 weeks of age. Plasma glucose and insulin concentrations were measured. Body weights were significantly greater in the sucrose group than in the control group in 18-week-old rats (P<0·05), and the difference between the two groups reached 163 g by the end of the study (P<0·01). The 120 min post-load plasma glucose concentration in the sucrose group was 11·4 (sd 2·8) mmol/l in 28-week-old rats and 12·7 (sd 2·2) mmol/l in 36-week-old rats, while that of the control group remained approximately 7·3–7·7 mmol/l. In the sucrose group, the plasma insulin peak occurred 30 min post-load at 28 weeks of age; but the peak disappeared and hyperinsulinaemia was prolonged at 36 weeks of age. In conclusion, long-term sucrose-drinking causes increased body weight and glucose intolerance in normal male rats.

The fine-grain processing of ingot metallurgy (IM) Mg–Y–Zn alloy, WZ73, was investigated. The alloy was initially produced by casting into a copper mold at a cooling rate of ∼50 K/s. The rapidly quenched bulk material was processed by means of equal channel angular extrusion (ECAE). The ECAE-processed material had equiaxed grains of 5.1 μm in size, and fine second-phase particles of Mg12YZn were dispersed in the grain boundaries. The Vickers hardness of the ECAE-processed material was 78. The dispersion of the second-phase particles, solid solution strengthening, and grain refinement contributed to the material’s hardness. The structure remained virtually unchanged, at least up to 673 K because the Mg12YZn phase served to pin the grain boundaries. The microstructure of IM WZ73 alloy, which is a suitable starting material for ECAE, was also considered.

The relationship between positron emission tomography (PET) findings and developmental or seizure outcome was examined in 17 infants (11 males, six females; mean age at onset of spasms 7 months, range 3 to 26 months) with newly diagnosed cryptogenic West syndrome. The predictive value of PET in these infants was assessed. PET was performed in the infants at the onset of spasms and 3 months after initial therapy using 18F-labelled 2-deoxy-2-fluoro-D-glucose. A third PET was performed at 18 months of age if the second scan was abnormal. All infants were followed up until at least 3 years of age. Cortical hypometabolism was detected in 11 infants on the first PET and in five infants on the second. Rate of developmental delay at the last follow-up was significantly higher in infants with hypometabolism on the second PET than in those without PET abnormalities (p<0.05). Rate of seizure occurrence after initial treatment was higher in infants with cortical hypometabolism on the second PET, but the difference was not statistically significant. Results suggest that when PET after the initial treatment shows no abnormalities, even though the first PET shows hypometabolism, infants with cryptogenic West syndrome may have a favourable developmental or seizure outcome. PET may be a useful tool in evaluating the prognosis in infants with cryptogenic West syndrome.

Localisation of the acrosome reaction inducing activity in egg-jelly was examined in the newt, Cynops pyrrhogaster. The jelly has six layers: the J0, J1, J2, J3, J4 and st layers. Jelly was mechanically dissected and placed on a Millipore filter. When sperm were added from the outer surface side of the jelly, most of them exhibited the acrosome reaction after passing through the jelly. When egg-jelly was divided into four layers, strong activity for the induction of acrosome reaction was detected in the outer layers, J4+st. These findings suggest that the acrosome reaction is induced by a substance in the outer layers of the egg-jelly. Among jelly components separated by SDS-PAGE, a fraction of more than 500 kDa in molecular weight induced the acrosome reaction. Wheat germ agglutinin (WGA), Griffonia simplicifoliar agglutinin 1 (GS-1), Maclura pomifera agglutinin (MPA) and Arachis hypogaea agglutinin (PNA) inhibited the induction of the acrosome reaction by jelly extract, and WGA did so in a dose-dependent manner. Those lectins precipitated some molecules of over 500 kDa. These results suggest that the acrosome reaction is induced by the high molecular-weight components of egg-jelly in C. pyrrhogaster.

We have constructed an advanced electric probing system, which is a triple-probe atomic force microscope (T-AFM). The T-AFM consists of “Nanotweezers” and an AFM with a carbon nanotube probe. Using this system, we fabricated a single-walled carbon nanotubes (SWNTs)/deoxyribonucleic acid (DNA) three-terminal device and measured the current-voltage (I-V) curves of this device. In this three-terminal device, DNA strands were entangled with the SWNT bundle, and behaved as a gate-insulator-layer. This three-terminal device worked as a metal-insulator-semiconductor field effect transistor (MIS-FET) with depletion switching behavior.

For measuring molecular device, we developed a dual-probe scanning tunneling microscope (D-STM) composed of two STM systems in which a carbon nanotube (NT) was used for STM tip. Using D-STM, we fabricated a NT ring device. The NT ring device showed a switching behavior with applying gate bias. Furthermore, in STM imaging for various gate biases, we could observe directly hole injection into the NT ring.

We have constructed an advanced electric probing system, which is a triple-probe atomic force microscope (T-AFM). The T-AFM consists of “Nanotweezers” and an AFM with a carbon nanotube probe. Using this system, we fabricated a single-walled carbon nanotubes (SWNTs)/deoxyribonucleic acid (DNA) three-terminal device and measured the current-voltage (I-V) curves of this device. In this three-terminal device, DNA strands were entangled with the SWNT bundle, and behaved as a gate-insulator-layer. This three-terminal device worked as a metal-insulator-semiconductor field effect transistor (MIS-FET) with depletion switching behavior.

For measuring molecular device, we developed a dual-probe scanning tunneling microscope (D-STM) composed of two STM systems in which a carbon nanotube (NT) was used for STM tip. Using D-STM, we fabricated a NT ring device. The NT ring device showed a switching behavior with applying gate bias. Furthermore, in STM imaging for various gate biases, we could observe directly hole injection into the NT ring.

β-Lactoglobulin (β-lg) is the main protein of ruminant milk whey. Although β-lg can bind in vitro to a variety of hydrophobic substrates, mainly retinol and long-chain fatty acids, its physiological function is still unknown. In Exp. 1, we investigated the effect of β-lg on the plasma retinol concentration in preruminant calves. Holstein male calves (n = 20) were fed Holstein whole milk at 40 g/kg body weight (BW) plus vitamin A acetate (500,000 i.u.) with or without β-lg (0·4 g/kg BW). The plasma retinol concentration of 10-d-old calves was greater (P<0·05) in the β-lg-fed group than in the control group during the period from 8 to 12 h and at 24 h after the feeding. The postprandial change of plasma retinol in 40-d-old calves fed milk with β-lg was higher (P<0·05) than that in the control calves only at 12 h after the feeding. In Exp. 2, Holstein male calves (n = 18) were used to investigate the effect of β-lg on plasma triglyceride concentration and fatty acid composition. Calves were fed Holstein whole milk at 40 g/kg BW plus milk fat prepared from whole milk at 2 g/kg BW with or without β-lg (0·4 g/kg BW). Plasma triglyceride concentration at age 10 d was higher (P<0·05) in the β-lg-fed group than in the controls during the periods from 1 to 2 h and from 7 to 11 h after the feeding. At age 40 d, plasma triglyceride in the β-lg-fed group was higher (P<0·05) than in the control group only at 9 h. Ratios of palmitic, stearic, and oleic acids to total plasma lipids were higher (P<0·05) in the calves fed β-lg milk than in the control calves at age 10 d. These results suggest that β-lg enhances the intestinal uptake of retinol, triglyceride, and long-chain fatty acids in preruminant calves.