STEADY-STATE ANALYSIS OF THE GI/M/1 QUEUE WITH MULTIPLE VACATIONS AND SET-UP TIME

In this paper, we consider a GI/M/1 queueing model with multiple vacations and set-up time. We derive the distribution and the generating function and the stochastic decomposition of the steady-state queue length, meanwhile, we get the waiting time distributions. Key words: multiple vacations, set-up time, stochastic decompositio

Non-Abelian dynamical gauge field and topological superfluids in optical Raman lattice

We propose an experimental scheme to realize non-Abelian dynamical gauge field for ultracold fermions, which induces a novel pairing mechanism of topological superfluidity. The dynamical gauge fields arise from nontrivial interplay effect between the strong Zeeman splitting and Hubbard interaction in a two-dimensional (2D) optical Raman lattice. The spin-flip transitions are forbidden by the large Zeeman detuning, but are restored when the Zeeman splitting is compensated by Hubbard interaction. This scheme allows to generate a dynamical non-Abelian gauge field that leads to a Dirac type correlated 2D spin-orbit interaction depending on local state configurations. The topological superfluid from a novel pairing driven by 2D dynamical gauge fields is reached, with analytic and numerical results being obtained. Our work may open up a door to emulate non-Abelian dynamical gauge fields and correlated topological phases with experimental feasibility.Comment: 5+7 pages, 4+6 figure

Global quark polarization in non-central A+AA+A collisions

Partons produced in the early stage of non-central heavy-ion collisions can develop a longitudinal fluid shear because of unequal local number densities of participant target and projectile nucleons. Under such fluid shear, local parton pairs with non-vanishing impact parameter have finite local relative orbital angular momentum along the direction opposite to the reaction plane. Such finite relative orbital angular momentum among locally interacting quark pairs can lead to global quark polarization along the same direction due to spin-orbital coupling. Local longitudinal fluid shear is estimated within both Landau fireball and Bjorken scaling model of initial parton production. Quark polarization through quark-quark scatterings with the exchange of a thermal gluon is calculated beyond small-angle scattering approximation in a quark-gluon plasma. The polarization is shown to have a non-monotonic dependence on the local relative orbital angular momentum dictated by the interplay between electric and magnetic interaction. It peaks at a value of relative orbital angular momentum which scales with the magnetic mass of the exchanged gluons. With the estimated small longitudinal fluid shear in semi-peripheral $Au+Au$ collisions at the RHIC energy, the final quark polarization is found to be small $|P_q|<0.04$ in the weak coupling limit. Possible behavior of the quark polarization in the strong coupling limit and implications on the experimental detection of such global quark polarization at RHIC and LHC are also discussed.Comment: 28 pages,11 figure

Effect of Baicalin on inflammatory mediator levels and microcirculation disturbance in rats with severe acute pancreatitis

Objective: To investigate the effect of Bacailin on inflammatory mediator levels and microcirculation disturbance in severe acute pancreatitis (SAP) rats and explore its therapeutic mechanism on this disease. Methods: SAP model rats were randomly divided into model control group and Baicalin treated group, 45 rats in each group. The same number of normal rats were included in sham-operated group. These groups were further subdivided into 3 h, 6 h and 12 h subgroups, respectively (15 rats in each subgroup). At 3, 6 and 12 hours after operation, rats were killed to conduct the following experiments: (1) to examine the mortality rates of rats, the ascites volume and pancreatic pathological changes in each group; (2) to determine the contents of amylase, PLA~2~, TXB~2~, PGE~2~, PAF and IL-1[beta]; in blood as well as the changes in blood viscosity.Results: (1) Compared to model control group, treatment with Baicalin is able to improve the pathological damage of the pancreas, lower the contents of amylase and multiple inflammatory mediators in blood, decrease the amount of ascitic fluid and reduce the mortality rates of SAP rats; (2) at 3 hours after operation, the low-shear whole blood viscosity in Baicalin treated group was significantly lower than that in model control group;at 12 hours after operation, both the high-shear and low-shear whole blood viscosity in Baicalin treated group were also significantly lower than those in model control group.Conclusion: Baicalin, as a new drug, has good prospects in the treatment of SAP since it can exert therapeutic effects on this disease through inhibiting the production of inflammatory mediators, lowering blood viscosity, improving microcirculation and mitigating the pathological damage of the pancreas

Inhibitory and Acceleratory Effects of Inonotus obliquus

The aim of the present study is to preliminarily investigate the antimelanogenesis effect of Inonotus obliquus extracts by cell-free mushroom tyrosinase assay. It was found that petroleum ether and n-butanol extracts might contain unknown potential tyrosinase inhibitors, while its ethyl acetate extract might contain some unknown accelerators. Six compounds were isolated and their structures were identified by interpretation of NMR data and nicotinic acid was first discovered in Inonotus obliquus. In cells testing, betulin and trametenolic acid decreased tyrosinase activity and melanin content, while inotodiol and lanosterol significantly increased tyrosinase activity and melanin content, showing an AC⁡50 of 9.74 and 8.43 μM, respectively. Nicotinie acid, 3β,22,25-trihydroxy-lanosta-8-ene, had a little or no effect on tyrosinase. Betulin exhibited a mode of noncompetitive inhibition with a KI=KIS of 0.4 μM on tyrosinase activity showing an IC50 of 5.13 μM and being more effective than kojic acid (6.43 μM), and trametenolic acid exhibited a mode of mixed inhibition with a KI of 0.9 μM, KIS of 0.5 μM, and an IC50 of 7.25 μM. We proposed betulin and trametenolic acid as a new candidate of potent tyrosinase inhibitors and inotodiol and lanosterol as accelerators that could be used as therapeutic agent

Dynamical evolution of spinodal decomposition in holographic superfluids

We study the nonlinear dynamical evolution of spinodal decomposition in a first-order superfluid phase transition using a simple holographic model in the probe limit. We first confirm the linear stability analysis based on quasinormal modes and verify the existence of a critical length scale related to a gradient instability -- negative speed of sound squared -- of the superfluid sound mode, which is a consequence of a negative thermodynamic charge susceptibility. We present a comparison between our case and the standard Cahn-Hilliard equation for spinodal instability, in which a critical length scale can be also derived based on a diffusive instability. We then perform several numerical tests which include the nonlinear time evolution directly from an unstable state and fast quenches from a stable to an unstable state in the spinodal region. Our numerical results provide a real time description of spinodal decomposition and phase separation in one and two spatial dimensions. We reveal the existence of four different stages in the dynamical evolution, and characterize their main properties. Finally, we investigate the strength of dynamical heterogeneity using the spatial variance of the local chemical potential and we correlate the latter to other features of the dynamical evolution.Comment: 19 pages, 13 figure

In vitro and in vivo studies on gelatin-siloxane nanoparticles conjugated with SynB peptide to increase drug delivery to the brain

National Natural Science Foundation of China [81172394, 30970733]; National Basic Research Program of China [2010CB732402]; Natural Science Foundation of Fujian Province of China [2006J0188]Background: Nanobiotechnology can provide more efficient tools for diagnosis, targeted and personalized therapy, and increase the chances of brain tumor treatment being successful. Use of nanoparticles is a promising strategy for overcoming the blood-brain barrier and delivering drugs to the brain. Gelatin-siloxane (GS) nanoparticles modified with Tat peptide can enhance plasmid DNA transfection efficiency compared with a commercial reagent. Methods: SynB-PEG-GS nanoparticles are membrane-penetrable, and can cross the blood-brain barrier and deliver a drug to its target site in the brain. The efficiency of delivery was investigated in vivo and in vitro using brain capillary endothelial cells, a cocultured blood-brain barrier model, and a normal mouse model. Results: Our study demonstrated that both SynB-PEG-GS and PEG-GS nanoparticles had a spherical shape and an average diameter of 150-200 nm. It was shown by MTT assay that SynB-PEG-GS nanoparticles had good biocompatibility with brain capillary endothelial cells. Cellular uptake by SynB-PEG-GS nanoparticles was higher than that for PEG-GS nanoparticles for all incubation periods. The amount of SynB-PEG-GS nanoparticles crossing the cocultured blood-brain barrier model was significantly higher than that of PEG-GS nanoparticles at all time points measured (P < 0.05). In animal testing, SynB-PEG-GS nanoparticle levels in the brain were significantly higher than those of PEG-GS nanoparticles at all time points measured (P < 0.01). In contrast with localization in the brain, PEG-GS nanoparticle levels were significantly higher than those of SynB-PEG-GS nanoparticles (P < 0.01) in the liver. Conclusion: This study indicates that SynB-PEG-GS nanoparticles have favorable properties with regard to morphology, size distribution, and toxicity. Moreover, the SynB-PEG-GS nanoparticles exhibited more efficient brain capillary endothelial cell uptake and improved crossing of the blood-brain barrier. Further, biodistribution studies of rhodamine-loaded nanoparticles demonstrated that modification with the SynB peptide could not only improve the ability of PEG-GS nanoparticles to evade capture in the reticuloendothelial system but also enhance their efficiency in crossing the blood-brain barrier