Rigid vortices in MgB2

Magnetic relaxation of high-pressure synthesized MgB$_2$ bulks with different thickness is investigated. It is found that the superconducting dia-magnetic moment depends on time in a logarithmic way; the flux-creep activation energy decreases linearly with the current density (as expected by Kim-Anderson model); and the activation energy increases linearly with the thickness of sample when it is thinner than about 1 mm. These features suggest that the vortices in the MgB$_2$ are rather rigid, and the pinning and creep can be well described by Kim-Anderson model.Comment: Typo corrected & reference adde

Emergence of diverse array of phases in an exactly solvable model

We propose an exactly solvable lattice model, motivated by the significance of the extended Hubbard model ($t-U-V$ model) and inspired by the work of Hatsugai and Kohmoto. The ground state exhibits a diverse array of phases, including the charge-$4e$ condensed phase, the charge-$2e$ superconducting phase, the half-filled insulating phase, the quarter-filled insulating phase, the metallic phase, and an unconventional metallic phase. Among them, the unconventional metallic phase could be of particular significance, for the coexistence of electrons and pairs at zero energy. These findings are poised to advance our understanding and exploration of strongly correlated physics.Comment: 34pages, 15 figure

Clinical and pathological analysis of 504 cases of elderly ocular tumors

AIM:To analyze the composition, distribution and characteristics of the elderly primary ocular tumors. <p>METHODS: This was a retrospective study and all 504 cases with primary ocular tumors aged 60 years or older were collected in Shanxi Eye Hospital, during the year 2000-2012. The onset age, location and pathological pattern were analyzed.<p>RESULTS: There were 346 cases of benign ocular tumors(68.7%), and 158 cases of malignancy(31.3%).Papillomas was the most common type of the benign with 83 cases(16.5%), followed by a variety of inflammatory cysts and lesions with 69 cases(13.7%)and 64 cases(12.7%)respectively. Among malignant tumors cases, eyelid basal cell carcinoma originated from epithelial was the most common with 72 cases(14.3%), followed by skin appendages sources malignant tumors with 39 cases(7.7%). Concerning the location of ocular tumors, there were 282 cases of eyelid tumor(56.0%)occupied the first position followed by conjunctival tumor with 157 cases(31.2%). <p>CONCLUSION: The prevalence and type of primary ocular tumor in elderly people are significant differences from the general population and children's, and the proportion of malignant tumors tended to increase along with the increase of age

cis-Bis[2-(1,3-benzothia­zol-2-yl)-1-(4-fluoro­phen­yl)ethen­yl](pentane-2,4-dionato-κ2 O,O′)iridium(III)

In the title compound, [Ir(C15H9FNS)2(C5H7O2)], the Ir atom is hexa­coordinated by three chelating ligands, with two cyclo­metalated 2-(1,3-benzothia­zol-2-yl)-1-(4-fluoro­phen­yl)ethenyl ligands showing N,C-bidentate coordination and an O,O′-bidenate pentane-2,4-dionate anion, thereby forming a distorted octa­hedral enviroment

Refined mapping of loss of heterozygosity in Chinese sporadic gastric carcinoma

The aim of this study is to explore precise deleted regions where the candidate tumor suppressor genes might be located in Chinese sporadic gastric carcinoma. By searching in Genothon, NCBI and GDB databases, 145 polymorphic microsatellite markers were chosen, at a mean density of approximately one marker every 2 - 4 cM, covering 15 chromosomes. These polymorphic microsatellite markers in gastric carcinoma and adjacent tissue were analyzed via PCR. PCR products were submitted to electrophoresis on an ABI 3730 DNA sequencer. Genemapper3.2 software was used for LOH (Loss of Heterozygosity) scanning and analysis. Comparison between LOH frequency and clinicopathological factors was performed by Fisher’s exact test. 26 refined regions were mapped as candidate regions for TSGs (Tumor suppression genes) in Chinese sporadic gastric cancer. Associations between LOH and clinical information indicated that 6 loci was associated with pTNM stage, 5 with Lauren's type, 4 with lymph nodes metastasis and another 2 with distant metastasis. Through refined deletion mapping, 26 candidate regions, where TSGs may be located, were found and 17 loci were proposed to be used as clinical markers in Chinese sporadic gastric cancer.Keywords: Gastric carcinoma, refined mapping, loss of heterozygosity (LOH), tumor suppressor genes (TSGs), tumor markersAfrican Journal of Biotechnology Vol. 9(35), pp. 5754-5761, 30 August, 201

4-[4,5-Bis(pyridin-2-yl)-1H-imidazol-2-yl]phenol monohydrate

In the title hydrate, C19H14N4O·H2O, the dihedral angle between the two pyridine rings is 38.0 (2)°. The dihedral angle between the imidazole and benzene rings is 25.3 (2)°. The crystal structure is stabilized by inter­molecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds

Possible Superconductivity at 37 K in Graphite-Sulfur Composite

Sulfur intercalated graphite composites with diamagnetic transitions at 6.7 K and 37 K are prepared. The magnetization hysteresis loops (MHL), Xray diffraction patterns, and resistance were measured. From the MHL, a slight superconducting like penetration process is observed at 15 K in low field region. The XRD shows no big difference from the mixture of graphite and sulfur indicating that the volume of the superconducting phase (if any) is very small. The temperature dependence of resistance shows a typical semiconducting behavior with a saturation in low temperature region. This saturation is either induced by the de-localization of conducting electrons or by possible superconductivity in this system.Comment: CHIN. PHYS.LETT v18 1648 (2001