Model-Independent Constraints on Lorentz Invariance Violation via the Cosmographic Approach

Since Lorentz invariance plays an important role in modern physics, it is of interest to test the possible Lorentz invariance violation (LIV). The time-lag (the arrival time delay between light curves in different energy bands) of Gamma-ray bursts (GRBs) has been extensively used to this end. However, to our best knowledge, one or more particular cosmological models were assumed {\it a priori} in (almost) all of the relevant works in the literature. So, this makes the results on LIV in those works model-dependent and hence not so robust in fact. In the present work, we try to avoid this problem by using a model-independent approach. We calculate the time delay induced by LIV with the cosmic expansion history given in terms of cosmography, without assuming any particular cosmological model. Then, we constrain the possible LIV with the observational data, and find weak hints for LIV.Comment: 15 pages, 4 figures, 3 tables, revtex4; v2: discussions added, Phys. Lett. B in pres

Draft Genome Sequence of Streptomyces sp. Strain CT34, Isolated from a Ghanaian Soil Sample

Copyright © 2015 Zhai et al. This work was supported by the China “973” program (2012CB721001), the “863” Program (2012AA092201), the National Natural Science Foundation of China (31170467), and the EU FP7 project PharmaSea (312184). K.K., M.J., and H.D. thank the Royal Society–Leverhulme Trust Africa for the financial support (award AA090088) that enabled the sampling of sediments and subsequent isolation of this unique Ghanaian strain.Non peer reviewedPublisher PD

Substrate entering and product leaving trajectories predict an engulfing dynamic for the major conformational change of the β-lactam acylase

It is still a major challenge to acquire insight into the conformational changes between the ground state and the transition state of an enzyme, although conformational fluctuation within interconverting conformers has been widely investigated (1-4). Here, we utilize different enzymatic reactions in b-lactam acylase to figure out the substrate/product trajectories in the enzyme, thereby probing the overall conformational changes in transition state. First, an auto-proteolytic intermediate of cephalosporin acylase (EC 3.5.1.11) with partial spacer segment was identified. As a final proteolytic step, the deletion of this spacer segment was revealed to be a first-order reaction, suggesting an intramolecular Ntn mechanism for the auto-proteolysis. Accordingly, the different proteolytic sites in the acylase precursor indicate a substrate entering pathway along the spacer peptide. Second, bromoacyl-7ACA can interact with penicillin G acylase (EC 3.5.1.11) in two distinguish aspects, to be hydrolyzed as a substrate analogue and to affinity alkylate the conserved Trpb4 as a product analogue. The kinetic correlation between these two reactions suggests a channel opening from Serb1 to Trpb4, responsible for the main product leaving. These two reaction trajectories relaying at the active centre, together with the crystal structures (5-10), predict an engulfing dynamic involving pocket constriction and channel opening

Effects of concurrent treatment with amitriptyline hydrochloride tablets and fluoxetine hydrochloride on therapeutic indicator levels in patients with depression

Purpose: To investigate the effects of combined treatment of amitriptyline hydrochloride tablets and fluoxetine hydrochloride on therapeutic indicator levels in depressive patients.Methods: Patients with depression (n = 104) were divided into control group and study group (52 cases each) using random number table method. Control group was treated with oral fluoxetine hydrochloride (FH) tablets only, while the study group received amitriptyline hydrochloride tablets, in addition to fluoxetine hydrochloride tablets. Both treatments lasted 3 months. Clinical effects and thyroid function indices were determined and compared for the two groups.Results: Treatment effectiveness in the study group (92.3 %) was markedly higher than that in control group (75.0 %, p < 0.05). In both groups, Pittsburgh Sleep Quality Index, Hamilton Depression Scale and Hamilton Anxiety Table scores significantly decreased post-treatment (p < 0.05). In contrast, there was significant increase in γ-aminobutyric acid (GABA) and serotonin (5-HT) levels in the two groups. In both groups, T3 and T4 significantly decreased while thyroid stimulating hormone (TSH) increased significantly (p < 0.05). Thyroid function in the study group was markedly higher than in the control group (p < 0.05).Conclusion: Combination treatment with amitriptyline hydrochloride tablets and FH is more effective than FH alone in the treatment of patients with depression. The combined treatment has a high degree of safety and is recommended for clinical application.Keywords: Amitriptyline hydrochloride, Fluoxetine hydrochloride, Depression, PSQI score, HAMD-17 score, HAMA score, GABA, 5-H