Neutron star matter in the quark-meson coupling model in strong magnetic fields

The effects of strong magnetic fields on neutron star matter are investigated in the quark-meson coupling (QMC) model. The QMC model describes a nuclear many-body system as nonoverlapping MIT bags in which quarks interact through self-consistent exchange of scalar and vector mesons in the mean-field approximation. The results of the QMC model are compared with those obtained in a relativistic mean-field (RMF) model. It is found that quantitative differences exist between the QMC and RMF models, while qualitative trends of the magnetic field effects on the equation of state and composition of neutron star matter are very similar.Comment: 16 pages, 4 figure

PHL 6625: A Minor Merger-Associated QSO Behind NGC 247

PHL 6625 is a luminous quasi-stellar object (QSO) at z = 0.3954 located behind the nearby galaxy NGC 247 (z = 0.0005). Hubble Space Telescope (HST) observations revealed an arc structure associated with it. We report on spectroscopic observations with the Very Large Telescope (VLT) and multiwavelength observations from the radio to the X-ray band for the system, suggesting that PHL 6625 and the arc are a close pair of merging galaxies, instead of a strong gravitational lens system. The QSO host galaxy is estimated to be (4-28) x 10^10 M_sun, and the mass of the companion galaxy of is estimated to be M_* = (6.8 +/- 2.4) x 10^9 M_sun, suggesting that this is a minor merger system. The QSO displays typical broad emission lines, from which a black hole mass of about (2-5) x 10^8 M_sun and an Eddington ratio of about 0.01-0.05 can be inferred. The system represents an interesting and rare case where a QSO is associated with an ongoing minor merger, analogous to Arp 142.Comment: ApJ to appea

Analysis and synthesis of randomly switched systems with known sojourn probabilities

In this paper, a new approach is proposed and investigated for the stability analysis and stabilizing controller design of randomly switched linear discrete systems. The approach is based on sojourn probabilities and it is assumed that these probabilities are known a prior. A new Lyapunov functional is constructed and two main theorems are proved in this paper. Theorem 1 gives a sufficient condition for a switched system with known sojourn probabilities to be mean square stable. Theorem 2 gives a sufficient condition for the design of a stabilizing controller. The applications of these theorems and the corresponding corollary and lemma are demonstrated by three numerical examples. Finally, some future research is proposed

Negative regulation of transcription coactivator p300 by orphan receptor TR3

p300 regulates the transcriptional activity of a variety of transcription factors by forming an activation complex and/or promoting histone acetylation. Here, we show a unique characteristic of orphan receptor TR3 in negatively regulating the function of p300. TR3 was found to interact with p300 and inhibited the acetylation of transcription factors induced by p300, resulting in the repression of their transcriptional activity. Further analysis revealed that both a conserved transcriptional adapter motif (TRAM) in p300 and a specific sequence FLELFIL in TR3 were critical for their interaction. TR3 binding completely covered the histone acetyltransferase (HAT) domain of p300 and resulted in suppression of the HAT activity, as the p300-induced histone H3 acetylation and transcription were inhibited with the presence TR3. Furthermore, an agonist of TR3, a natural octaketide isolated from Dothiorella sp. HTF3 of an endophytical fungus, was shown to be a potent compound for inhibiting p300 HAT activity (IC50=1.5 mu g/ml) in vivo. More importantly, this agonist could repress the transcriptional activity of transcription factors, and proliferation of cancer cells. Taken together, our results not only delineate a novel transcriptional repressor function for TR3, but also reveal its modulation on p300 HAT activity as the underlying mechanism

Substrate Profile Analysis and ACP-Mediated Acyl Transfer in Streptomyces coelicolor Type III Polyketide Synthases

No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56089/1/863_ftp.pd

Finite element analysis of mechanical behavior, permeability of irregular porous scaffolds and lattice-based porous scaffolds

In view of the low elastic modulus of the porous structure, it has attracted extensive attention in the field of artificial tissue implants for bone tissue engineering, and it has become important to find a porous structure suitable for human bone tissue. In this study, we constructed three type regular porous structure (cube, diamond, rhombohedral dodecahedron) and an irregular porous structure based on Voronoi tessellation. Firstly, the structural characteristics of porous structures were studied. After permeation simulation and compression simulation, we found that the structural characteristics (porosity, pore size, specific surface area) of four porous structures have a strong positive correlation with permeability. With the increase of porosity, the effective elastic modulus of the four porous structures decreases gradually. When the porosity is 80%, the effective elastic modulus and permeability of the four porous structures can basically meet the requirements of human bone implants. Irregular porous scaffolds exhibit relatively limited anisotropy in terms of mechanical properties and permeability. In view of the similarity between the structure and the human bone, the irregular porous structure exhibits superior development and application potential compared to the regular porous structure

CHEMICAL CONSTITUENTS FROM THE STEM BARK OF Alangium kurzi, Craib

Three new chemical constituents have been isolated from the stem bark of Alangium kurzii Craib. The structures were respectively determined to be 4-cyclohexene-1,2,3-triol 1, 3-β-stigmast-5-en-3-ol (β-sitosterol 2), and 3-O-β-D-glucopyranosyl-stigmast-5-ene (daucosterol 3). These compounds are preliminary isolated from this plant. Keyword: Alangium kurzii, Alangiaceae, 4-cyclohexene-1,2,3-triol, β-sitosterol, daucosterol