High spin baryon in hot strongly coupled plasma

We consider a strings-junction holographic model of probe baryon in the finite-temperature supersymmetric Yang-Mills dual of the AdS-Schwarzschild black hole background. In particular, we investigate the screening length for high spin baryon composed of rotating N_c heavy quarks. To rotate quarks by finite force, we put hard infrared cutoff in the bulk and give quarks finite mass. We find that N_c microscopic strings are embedded reasonably in the bulk geometry when they have finite angular velocity \omega, similar to the meson case. By defining the screening length as the critical separation of quarks, we compute the \omega dependence of the baryon screening length numerically and obtain a reasonable result which shows that baryons with high spin dissociate more easily. Finally, we discuss the relation between J and E^2 for baryons.Comment: 18 pages, 19 figures, version to appear in JHE

Holography and noncommutative Yang-Mills theory

Journal ArticleIn this Letter a recently proposed gravity dual of noncommutative Yang-Mills theory is derived from the relations between closed string moduli and open string moduli recently suggested by Seiberg and Witten. The only new input one needs is a simple form of the running string tension as a function of energy. This derivation provides convincing evidence that string theory integrates with the holographical principle and demonstrates a direct link between noncommutative Yang-Mills theory and holography

2,9-Bis(4-pyridylmeth­oxy)-1,10-phenanthroline

In the title mol­ecule, C24H18N4O2, the dihedral angles between the mean plane of the phenanthroline ring system and the pyridine rings are 82.52 (5) and 71.58 (4)°. The dihedral angle between the two pyridine ring planes is 53.54 (6)°. In the crystal structure, there are π–π stacking inter­actions between 1,10-phenanthroline rings, with centroid–centroid distances of 3.6101 (11) and 3.5864 (11) Å

An Opposite Effect of the CDK Inhibitor, p18^INK4c on Embryonic Stem Cells Compared with Tumor and Adult Stem Cells

Self-renewal is a feature common to both adult and embryonic stem (ES) cells, as well as tumor stem cells (TSCs). The cyclin-dependent kinase inhibitor, p18INK4c, is a known tumor suppressor that can inhibit self-renewal of tumor cells or adult stem cells. Here, we demonstrate an opposite effect of p18 on ES cells in comparison with teratoma cells. Our results unexpectedly showed that overexpression of p18 accelerated the growth of mouse ES cells and embryonic bodies (EB); on the contrary, inhibited the growth of late stage teratoma. Up-regulation of ES cell markers (i.e., Oct4, Nanog, Sox2, and Rex1) were detected in both ES and EB cells, while concomitant down-regulation of various differentiation markers was observed in EB cells. These results demonstrate that p18 has an opposite effect on ES cells as compared with tumor cells and adult stem cells. Mechanistically, expression of CDK4 was significantly increased with overexpression of p18 in ES cells, likely leading to a release of CDK2 from the inhibition by p21 and p27. As a result, self-renewal of ES cells was enhanced. Our current study suggests that targeting p18 in different cell types may yield different outcomes, thereby having implications for therapeutic manipulations of cell cycle machinery in stem cells. © 2012 Li et al

Chlorido[2,2′-(oxydimethyl­ene)­dipyridine]copper(II) perchlorate–aqua­chlorido[2,2′-(oxydimethyl­ene)­dipyridine]copper(II) perchlorate (1/1)

The asymmetric unit of the title compound, [CuCl(C12H12N2O)][CuCl(C12H12N2O)(H2O)](ClO4)2, contains two different discrete cations. In one cation, the CuII ion is coordinated in a slightly distorted square-planar geometry, while in the other the CuII ion is in a slightly distorted square-pyramidal environment. In the crystal structure, there are O—H⋯O hydrogen bonds between coordinated water mol­ecules and perchlorate anions. Both types of cations are linked into one-dimensional chains along the b axis by weak electrostatic Cu⋯Cl inter­actions, with Cu⋯Cl distances of 2.8088 (16) and 3.2074 (17) Å