Magnetic characteristics of RPd2Si2 (R = Rare earth)

Magnetic characteristics of HoPd2Si2 and ErPd2Si2 with the ThCr2Si2-type crystal structure have been studied from measurements of magnetic susceptibility χ(T) and magnetization M(B) on the single crystals. The compound HoPd2Si2 orders antiferromagnetically below TN = 5.1 K with the magnetic easy direction of [110]. The [110] magnetization process is a three-step metamagnetic one; metamagnetic transitions at B1 = 0.9 T, B2 = 1.5 T and B3 = 3.4 T. The [100] process is a two-step one. Between [110] and [100], strong magnetic anisotropy is seen for high magnetic fields. ErPd2Si2 shows an antiferromagnetic behavior with the magnetic easy direction of [001] below TN=3.9 K. The χ(T) shows four anomalies, which may come from magnetic transitions, at Tmax = 5.1 K, TN = T1 = 3.9 K, T2 = 3.1 K and T3 = 2.2 K. The [001] magnetization process at 2 K is a three-step metamagnetic process; metamagnetic transitions at B1 = 0.5 T, B2 = 1.0 T and B3 = 1.3 T. In the basal plane magnetization processes, a very small metamagnetic transition is at 1.9 T. Crystalline electric field (CEF) analysis was performed, and anisotropic magnetic behaviors are explained. The magnetic data of the RPd2Si2 compound series are summarized

Increased cellular resistance to oxidative stress by expression of cyanobacterium catalase-peroxidase in animal cells

AbstractTo exploit prokaryotic antioxidant enzymes for protection of animal cells from oxidative damage, we expressed catalase-peroxidase of cyanobacterium Synechococcus PCC 7942 in 104C1 cells. The gene for this enzyme was inserted into the mammalian expression vector pRc/CMV. The stable transfectants obtained had higher specific activities of catalase and as a result became more resistant to H2O2 or paraquat than the parental cells. Subcellular fractionation and immunoblot analysis revealed that the expressed catalase-peroxidase was confined to the cytosol; this localization may be the basis for the effective protection of the transfectants from the oxidative cell damage

Experimental set-up for thermopower measurement under high pressure using "seesaw heating method"

We have developed a set-up with modified "seesaw heating method" for the simultaneous measurement of thermopower S and electrical resistivity р under hydrostatic pressures P up to 3 GPa at the temperature range between 1.5 K and 300 K. By using this set-up, S and р of single crystalline YbMn_2Ge_2 and EuCo_2P_2 under high pressure were measured with enough accuracy. The temperature dependences of S and р show drastic changes at the critical pressure P_c in both compounds. The measurement results indicate that the simultaneous measurement of S and р is a usuful tool to study the pressure-induced phase transitions