First-principles study on superconductivity of P- and Cl-doped H3_3S

The recent reports on 203 K superconductivity in compressed hydrogen sulfide, H$_3$S, has attracted great interest in sulfur-hydrogen system under high pressure. Here, we investigated the superconductivity of P-doped and Cl-doped H$_3$S using the first-principles calculations based on the supercell method, which gives more reliable results on the superconductivity in doped systems than the calculations based on the virtual crystal approximation reported earlier. The superconducting critical temperature is increased from 189 to 212 K at 200 GPa in a cubic $Im\bar{3}m$ phase by the 6.25 % P doping, whereas it is decreased to 161 K by the 6.25 % Cl doping. Although the Cl doping weakens the superconductivity, it causes the $Im\bar{3}m$ phase to be stabilized in a lower pressure region than that in the non-doped H$_3$S.Comment: 7 pages, 5 figures, 5 tables, submitted to Physical Review

Atomically Resolved Surface Structure of SrTiO3(001) Thin Films Grown in Step-Flow Mode by Pulsed Laser Deposition

The surface structure of SrTiO3(001) thin films homoepitaxially grown by PLD in step-flow mode was characterized using low temperature STM. It was found that one-dimensional (1D) TiOx-based nanostructures were formed on the thin film surface and their density increased with increasing thin film thickness. Most of the 1D nanostructures disappeared after a post-deposition annealing, indicating that this structure is metastable due to the nonequilibrium growth mode. The resulting surface after annealing exhibited similar features to that of a thinner film, having a domain structure with (2x1) and (1x2) reconstructions, but with fewer oxygen-vacancy-type defects. These results imply that the step-flow growth is likely to produce TiOx-rich surface and Ti deficiencies in the film. By the post-deposition annealing, the rich TiOx would diffuse from the surface into the film to compensate defects associated with Ti vacancies and oxygen vacancies, resulting in the stable surface structure with fewer oxygen vacancies. Thus, STM measurements can provide us with a microscopic picture of surface stoichiometry of thin films originating in the dynamics of the growth process, and can present a new approach for designing functional oxide films.Comment: 12 pages, 4 figure

SCOP, a novel gene product expressed in a circadian manner in rat suprachiasmatic nucleus

AbstractTo elucidate the mechanism of the circadian rhythm, genes differentially expressed during subjective day and night in the rat suprachiasmatic nucleus (SCN), a circadian oscillator in mammals, were surveyed by a differential display method. We isolated a novel gene, scop (SCN circadian oscillatory protein), that was expressed in a circadian manner in the SCN. SCOP protein is predominantly expressed in the brain and has domains including a pleckstrin homology domain, leucine-rich repeats, a protein phosphatase 2C-like domain and a glutamine-rich region. The structural feature of SCOP protein suggests its role in the intracellular signaling in the SCN

Intra-Day Variation of Urinary Nuclear Matrix Protein 22

Nuclear Matrix Protein 22 (NMP22), a urinary tumor marker for urothelial cancers, is directly released into the urine from the nucleus after cell death, Accordingly, values of NMP22 do not requlre adjustment using other substances such as urinary creatinine. On the other hand, its values might vary according to urine concentration. This study investigated the intra-day variation in the urinary level of NMP22. NMP22 and urinary creatinine were measured in a 24-hour urine sample and 4 spot urine samples obtained from 20 inpatients (10 with bladder cancer, and 10 with non-urothelial cancer or benign tumors). The spot urine samples were collected at 6 a.m., 10 a.m., 2p.m. and 9 p.m. There were no significant differences in NMP22 values between the 24-hour and spot samples in all patients. Out of 10 bladder cancer patients, 6 had positive 24-hour samples. Among these 6 patients, only 3 had 4 positive spot samples (>12.O U/ml): one had 3 positive samples, and 2 had one positive sample. Among the controls, only one patient with renal cancer had a positive 24-hour sample. Only 3 controls, 2 With prostatic cancer and one with renal cancer, had a single positive spot sample. The highest margin between the maximum and minimum levels in the 4 spot samples was 237.8 U/ml in the bladder cancer patients and 16.6 U/ml in the controIs. When the ratios of NMP22 and urinary creatinine values for the 24-hour to spot samples were calculated in each patient, a significant correlation was observed between the ratios of NMP22 and urinary creatinine (r=0.575, p<0.001). The urinary level of NMP22 shows intra-day variation and might be affected by the extent of the concentration of urine samples. The measurement results must be judged with this in mind, especially when judging the results around the cut-off value

Crystal Structure of 200 K-Superconducting Phase of Sulfur Hydride System

This article reports the experimentally clarified crystal structure of a recently discovered sulfur hydride in high temperature superconducting phase which has the highest critical temperature Tc over 200 K which has been ever reported. For understanding the mechanism of the high superconductivity, the information of its crystal structure is very essential. Herein we have carried out the simultaneous measurements electrical resistance and synchrotron x-ray diffraction under high pressure, and clearly revealed that the hydrogen sulfide, H2S, decomposes to H3S and its crystal structure has body-centered cubic symmetry in the superconducting phase.Comment: 8 pages, 3 figure