Holographic Shear Viscosity in Hyperscaling Violating Theories without Translational Invariance

In this paper we investigate the ratio of shear viscosity to entropy density, $\eta/s$, in hyperscaling violating geometry with lattice structure. We show that the scaling relation with hyperscaling violation gives a strong constraint to the mass of graviton and usually leads to a power law of temperature, $\eta/s\sim T^\kappa$. We find the exponent $\kappa$ can be greater than two such that the new bound for viscosity raised in arXiv:1601.02757 is violated. Our above observation is testified by constructing specific solutions with UV completion in various holographic models. Finally, we compare the boundedness of $\kappa$ with the behavior of entanglement entropy and conjecture a relation between them.Comment: 38 pages, 8 figures: 1 appendix added, 2 figures added, 1 references adde

Synergistic behaviour of Salvia and Notoginseng species in vascular diseases

As the mainstay and principal form of traditional Chinese medicine (TCM), Chinese herbal medicine (CHM) has been the subject of growing interest and popular use worldwide. However, its unique philosophy, diagnosis and prescription are completely different from Western Medicine (WM), which has brought great challenges for the quality standardisation, safety control, and efficacy evaluation confronting its development in a modernised scientific manner. This PhD project aims to address challenges that revolve around the efficacy research of CHM. Based on CHM theory, the key mechanism of the efficacy of CHM is the synergistic interactions among multiple herbal ingredients in a formula to reach an optimised therapeutic effect, multi-target mode of actions and reduced potential side effects. Several rigorous analytical methods such as combination index (CI), isobolographic analysis and systems biology are designed for the quantitative evaluations of synergistic effects in pharmaceutical combination therapy, and have also been utilised for the study of CHM. Among them, CI and isobologram models are applied for studying the interactions of a small number of active components or herbal extracts on the same target or receptor in which their chemical and pharmacological properties are well defined. A systems biology model may also be used to analyse multi-component, multi-target actions in combinational therapy. However, following a systematic review, it is apparent that the current literature on synergistic study of CHM is still at an early stage. Based on previous studies, we hypothesised that a platform to systematically analyse synergistic interactions of herbal compounds can be established by modern bioassays and scientific models (e.g., CI and isobologram approaches). Herb-pairs are the basic unit for the Chinese herbal formulae. Salvia Miltiorrhiza Radix et Rhizoma and Notoginseng Radix et Rhizome (known as Danshen [DS] and Sanqi [SQ] in TCM) has been one of the most frequently prescribed herb pairs in TCM clinics for cardiovascular disease management for over 30 years in Asian countries. However, very limited mechanistic studies on the combinational benefits on the complex pathological mechanisms of vascular diseases are available, despite the fact that the bioactivities for a single extract have been well studied. Therefore, the DS-SQ herb-pair was selected as a case study to address the issue of synergistic activities in CHM

Distinct Role of IL-27 in Immature and LPS-Induced Mature Dendritic Cell-Mediated Development of CD4

Interleukin-27 (IL-27) plays an important role in regulation of anti-inflammatory responses and autoimmunity; however, the molecular mechanisms of IL-27 in modulation of immune tolerance and autoimmunity have not been fully elucidated. Dendritic cells (DCs) play a central role in regulating immune responses mediated by innate and adaptive immune systems, but regulatory mechanisms of DCs in CD4+ T cell-mediated immune responses have not yet been elucidated. Here we show that IL-27 treated mature DCs induced by LPS inhibit immune tolerance mediated by LPS-stimulated DCs. IL-27 treatment facilitates development of the CD4+ CD127+3G11+ regulatory T cell subset in vitro and in vivo. By contrast, IL-27 treated immature DCs fail to modulate development of the CD4+CD127+3G11+ regulatory T cell sub-population in vitro and in vivo. Our results suggest that IL-27 may break immune tolerance induced by LPS-stimulated mature DCs through modulating development of a specific CD4+ regulatory T cell subset mediated by 3G11 and CD127. Our data reveal a new cellular regulatory mechanism of IL-27 that targets DC-mediated immune responses in autoimmune diseases such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). © 2018 Zhou, Zhang and Rostami

Optimal Online Transmission Policy for Energy-Constrained Wireless-Powered Communication Networks

This work considers the design of online transmission policy in a wireless-powered communication system with a given energy budget. The system design objective is to maximize the long-term throughput of the system exploiting the energy storage capability at the wireless-powered node. We formulate the design problem as a constrained Markov decision process (CMDP) problem and obtain the optimal policy of transmit power and time allocation in each fading block via the Lagrangian approach. To investigate the system performance in different scenarios, numerical simulations are conducted with various system parameters. Our simulation results show that the optimal policy significantly outperforms a myopic policy which only maximizes the throughput in the current fading block. Moreover, the optimal allocation of transmit power and time is shown to be insensitive to the change of modulation and coding schemes, which facilitates its practical implementation.Comment: 7 pages, accepted by ICC 2019. An extended version of this paper is accepted by IEEE TW