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Abstract: Background: Rabeprazole 10mg b.i.d. is often administered as therapy for eradication of Helicobacter pylori (H. pylori) and is also proposed as therapy for refractory gastro-oesophageal reflux disease. However, there has not been a comprehensive assessment of its acid-suppressive effects. Aims: To compare the acid-suppressive effects of rabeprazole 10mg b.i.d. with 20mg b.i.d. considering H. pylori status. Subjects: Thirteen H. pylori-negative and eleven H. pylori-positive Japanese CYP2C19 extensive metabolisers (<35 years). Methods: Intragastric pH was measured for 24h three times in a randomised manner; on day 7 of the repeated administration of rabeprazole 10mg b.i.d. or 20mg b.i.d., or a placebo. Results: In median intragastric pH value and percent time of pH>3.0, >4.0, >5.0, >6.0, and >7.0 for 24h, no significant differences were observed between the two doses in either H. pylori-negative or H. pylori-positive subjects. At either dose, these parameters were significantly higher in H. pylori-positive subjects than in H. pylori-negative subjects. Nocturnal acid breakthrough occurred in seven and two of the thirteen H. pylori-negative subjects and one and two of the eleven H. pylori-positive subjects at each dose, respectively. Conclusions: The effects of rabeprazole 10mg b.i.d. were equal to those of 20mg b.i.d. in H. pylori-positive subjects; whereas in H. pylori-negative subjects, 20mg b.i.d. was superior for prevention of nocturnal acid breakthrough. [Copyright &y& Elsevier]

The deformation behavior of single crystals of TiSi2 with the orthorhombic C54 structure has been investigated as a function of crystal orientation in the temperature range from room temperature to 1400 °C in compression. Plastic flow is possible only when slip along <110> on (001) is operative and no other slip systems are observed in the whole temperature range investigated. While plastic flow is observed above 300 °C for as-grown crystals, the onset temperature for plastic flow is lowered considerably down to room temperature when the crystal is prestrained at 1300 °C and then re-deformed at low temperatures. The critical resolved shear stress (CRSS) for (001)<110> slip decreases with increasing temperature, exhibiting a moderate peak (or plateau) in the temperature range from 800 to 1100 °C. The deformation mechanism of TiSi2 is discussed in comparison with those reported for other transition-metal disilicides with the C11b and C40 structures, which are closely related to the C54 structure of TiSi2. [Copyright &y& Elsevier]