The gastroprotective activity of phytosphingosine hydrochloride (PS-HCl, CAS 554-62-1) was assessed in four different rat models of experimentally induced gastric ulcer. Various doses (2.5-10 mg/kg) of PS-HCI were orally administered to rats 30 min before the treatment with HCl/ethanol, indometacin, cysteamine, or to rats with ligated pylorus. Oral administration of PS-HCl (2.5-10 mg/kg) to rats prevented the acute ulcer formation in 4 different types of ulcer in a dose-dependent manner as follows: (1) HCl/ethanol-induced gastric mucosal membrane lesions (20.1-47.8% inhibition), (2) indometacin-induced gastric mucosal membrane lesions (4.6-31.9% inhibition), (3) duodenal ulcer induced by cysteamine (10-20% inhibition), (4) gastric secretion and ulceration following pylorus ligation (33.3-61.9% inhibition). These results indicate that PS-HCI may be useful for the prevention of gastric ulcer.

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CeIn3, a prototypical antiferromagnet, is an ideal candidate for investigating the relationship between magnetism and superconductivity, as superconductivity is induced as the magnetic transition temperature (T N) is lowered to 0 K by applying pressure. When La is substituted for Ce, T N of CeIn3 decreases to 0 K owing to the Ce dilution effects, thereby providing an alternative route to the zero-temperature quantum phase transition. In this study, we report a combinatorial approach to gain access to the critical point by applying external pressure to 20% La-doped CeIn3. Electrical resistivity measurements of La0.2Ce0.8In3 show that the T N of 8.4 K at 1 bar is gradually suppressed under pressure and can be extrapolated to 0 K at approximately 2.47 GPa, thereby showing a similar pressure dependence of T N as shown by undoped CeIn3. The kink-like feature in resistivity at T N of CeIn3 changed to an obvious jump in the doped compound for pressures higher than 1.64 GPa, indicating depletion in the carrier density due to a gap opening. AC calorimetry measurements under applied pressure show that the size of the specific heat jump at T N decreases with increasing pressure, but any signatures associated with the gap opening are not obvious, suggesting that the pressure-induced kink-to-jump change at T N in the resistivity is not a phase transition, but rather a gradual crossover. The low-temperature specific heat divided by temperature, C/T, does not strongly diverge with decreasing temperature, but is almost saturated near the projected quantum critical point, which can be attributed to a weak enhancement in the effective mass up to 2.6 GPa.