Large spontaneous spin splitting in gate-controlled two-dimensional electron gases at normal In_<0.75>Ga_<0.25>As/In_<0.75>Al_<0.25>As heterojunctions

Amounts of spontaneous spin splittings were estimated from low-temperature magnetoresistances in two-dimensional electron gases created at In_Ga_As/In_Al_As heterojunctions under a gate bias. Typical sheet electron densities and mobilities in the raw wafers were ～1.0×10^/cm^2 and 2-5×10^5 cm^2/V s at 1.5 K, respectively. A maximum spin-orbit coupling constant α_ of ～30(×10^ eV m) was obtained for the van der Pauw sample. In gated Hall-bar samples, a decrease in the α_ value with decreasing gate voltage (V_g) was first confirmed in a normal heterojunction. The main origin for such a large α_, which is a few times larger than any previously reported, was found to be a structure-dependent so-called interface contribution in the Rashba term

Tunneling conductivity in lithiated transition metal oxide cathode Li 0.9 [Ni 1/3 Mn 1/3 Co 1/3 ]O 1.95

Electrical complex ac conductivity of the compound Li 0.9 [Ni 1/3 Mn 1/3 Co 1/3 ]O 1.95 has been studied in the frequency range 10 Hz–2 MHz and in the temperature range 93–373 K. It has been observed that the frequency dependence of the ac conductivity obeys a power law and the temperature dependence of the ac conductivity is quite weak. The experimental data have been analyzed in the framework of several theoretical models based on quantum mechanical tunneling and classical hopping over barriers. It has been observed that the electron tunneling is dominant in the temperature range from 93 K to 193 K. A crossover of relaxation mechanism from electron tunneling to polaron tunneling is observed at 193 K. Out of the several models discussed, the electron tunneling and the polaron tunneling models are quite consistent with the experimental data for the complex ac conductivity. The various parameters obtained from the fits of the experimental results for the real and imaginary parts of the conductivity to the predictions of these models are quite reasonable. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011

IRF6 Screening of Syndromic and a priori Non-Syndromic Cleft Lip and Palate Patients: Identification of a New Type of Minor VWS Sign.

Van der Woude syndrome (VWS), caused by dominant IRF6 mutation, is the most common cleft syndrome. In 15% of the patients, lip pits are absent and the phenotype mimics isolated clefts. Therefore, we hypothesized that some of the families classified as having non-syndromic inherited cleft lip and palate could have an IRF6 mutation. We screened in total 170 patients with cleft lip with or without cleft palate (CL/P): 75 were syndromic and 95 were a priori part of multiplex non-syndromic families. A mutation was identified in 62.7 and 3.3% of the patients, respectively. In one of the 95 a priori non-syndromic families with an autosomal dominant inheritance (family B), new insights into the family history revealed the presence, at birth, of lower lip pits in two members and the diagnosis was revised as VWS. A novel lower lip sign was observed in one individual in this family. Interestingly, a similar lower lip sign was also observed in one individual from a 2nd family (family A). This consists of 2 nodules below the lower lip on the external side. In a 3rd multiplex family (family C), a de novo mutation was identified in an a priori non-syndromic CL/P patient. Re-examination after mutation screening revealed the presence of a tiny pit-looking lesion on the inner side of the lower lip leading to a revised diagnosis of VWS. On the basis of this data, we conclude that IRF6 should be screened when any doubt rises about the normality of the lower lip and also if a non-syndromic cleft lip patient (with or without cleft palate) has a family history suggestive of autosomal dominant inheritance