Inflammatory bowel diseases (IBD) are based on chronic inflammation in the gastrointestinal tract. We previously found anti-inflammatory peptide pyroGlu-Leu in the enzymatic hydrolysate of wheat gluten. The objective of present study is to elucidate improvement of colitis by oral administration of pyroGlu-Leu in an animal model. Acute colitis was induced by dextran sulfate sodium (DSS), and various concentrations of pyroGlu-Leu were administrated by oral gavage for 7 days. A dose of 0.1 mg/kg body weight/day showed the most significant improvement. The pyroGlu-Leu concentration was significantly increased 24 h after oral administration both in the small intestine and the colon compared with the baseline. It was 20-fold higher in the small intestine than the colon. Administration of pyroGlu-Leu normalized population of Bacteroidetes and Firmicutes in the colon. These results indicate that pyroGlu-Leu has a potential therapeutic effect against IBD at a practical dose.

Abstract. Polar stratospheric clouds (PSCs) were observed by lidar at Ny-.•lesund, Spitsbergen, in December 1994 and January 1995. The backscattering coefficient at wavelengths of 1064 and 532 nm and the depolarization ratio at 532 nm of PSCs were measured by the lidar system. The stratospheric temperature was below the estimated frost point of nitric acid tri-hydrate (NAT) in the winter of 1994/1995. PSCs were observed more frequently in this low-temperature period than in previous winters since 1991. The characteristics of the PSCs were very variable but had a noticeable vertical "sandwich" structure in January in which a layer of liquid PSC particles at the altitude around 20 km existed between the two solid particle layers. The wavelength dependence of the backscattering shows that the size of both liquid and solid particles was larger than the average size of background stratospheric aerosols. Lidar observations of the liquid layer particles show characteristics in qualitative agreement with those expected from model PSC particles grown in ternary solutions of H2SO4, HNO3, and H20 with a temperature decrease. However, the observed backscattering coefficient and its wavelength dependence indicate that PSC particles require further growth than that predicted by the ternary solution model at temperature where most HNO 3 molecules in the surrounding atmosphere are considered to be condensed on PSCs.

The deformation behavior of Ti 5 Si 3 single crystals with the hexagonal D8 8 structure has been investigated in compression as a function of crystal orientation in a temperature range from 1200 to 1500°C. Three different types of deformation modes -{1 1 0 0}[0 0 0 1] prismatic slip, {2 1 1 2}1/3h2 1 1 3i pyramidal slip and {2 1 1 8}h8 4 4 3i twinning -were identified for the first time as being operative in Ti 5 Si 3 at temperatures above 1300°C, depending on the loading axis orientation. The critical resolved shear stresses (CRSSs) decrease steeply with increasing temperature for all deformation modes. The values of the CRSSs for {1 1 0 0}[0 0 0 1] prismatic slip are considerably lower than those for {2 1 1 2}1/3h2 1 1 3i pyramidal slip, but are comparable to those for {2 1 1 8}h8 4 4 3i twinning. The favored deformation modes are discussed on the basis of anisotropic elasticity theory of dislocations.

A fine calibration of the depolarization ratio is required for a detailed interpretation of lidar-observed polar stratospheric clouds. We propose a procedure for analyzing data by using atmospheric depolarization lidar. The method is based on a plot of deltaT versus (1 - RT(-1)), where deltaT is the total depolarization ratio and RT is the total backscattering ratio. Assuming that there are only spherical particles in some altitude ranges of the lidar data, the characteristics of the plot of deltaT versus (1 - RT(-1)) lead to a simple but effective calibration method for deltaT. Additionally, the depolarization of air molecules deltam can be determined in the process of deltaT calibration. We compared determined values with theoretically calculated values for the depolarization of air to test the proposed method. The deltam value was calculated from the lidar data acquired at Ny-Alesund (79 degrees N, 12 degrees E), Svalbard in winter 1994-1995. When only sulfate aerosols were present on 24 December 1994, deltam was 0.46 +/- 0.35%. When the particles consisted of sulfate aerosols and spherical particles of polar stratospheric clouds on 4 January 1995, deltam was 0.45 +/- 0.07%. Both deltam values were in good agreement with the theoretically calculated value, 0.50 +/- 0.03%.

The phase transitions for a homologous series of semifluorinated n-alkanes, F(CF 2 ) 10 (CH 2 ) m H, with 2 e m e 19 (F10Hm), have been characterized using a polarizing microscope, DSC, X-ray diffraction, and dilatometry. Thermal analysis and optical textures indicate the presence of the smectic-smectic phase transition when the number of methylene units ranges from 6 to 12. The phase-transition temperature depends on the length (m) of the hydrocarbon segment. The density decreases with increases in the carbon number of the hydrogen segment. The data for both the thermal properties and the density suggest that the smectic-smectic phase transition is significantly first-order, which is primarily caused by a change in the molecular packing for the molecular rearrangement, while a transition for the clearing point is related to disordering of the entire molecule. The volume jump shows that F10Hm have the same molecular packing in the high-temperature mesophase and that their magnitude is greater than that of the conventional liquid crystalline compounds having an aromatic-mesogenic core. The effects of the fluorinated segment for the phase transitions are also discussed herein.