Picornaviruses cause several diseases, not only in humans but also in various animal hosts. For instance, human enteroviruses can cause hand-foot-and-mouth disease, herpangina, myocarditis, acute flaccid paralysis, acute hemorrhagic conjunctivitis, severe neurological complications, including brainstem encephalitis, meningitis and poliomyelitis, and even death. The interaction between the virus and the host is important for viral replication, virulence and pathogenicity. This article reviews studies of the functions of viral and host factors that are involved in the life cycle of picornavirus. The interactions of viral capsid proteins with host cell receptors is discussed first, and the mechanisms by which the viral and host cell factors are involved in viral replication, viral translation and the switch from translation to RNA replication are then addressed. Understanding how cellular proteins interact with viral RNA or viral proteins, as well as the roles of each in viral infection, will provide insights for the design of novel antiviral agents based on these interactions.

The human glioblastoma SF268 cell line was used to investigate the induction of apoptosis by the 3C protease of enterovirus 71 (EV71). Transient expression in these cells of the wild-type 3C protein encoded by EV71 induced morphological alterations typical of apoptosis, including generation of apoptotic bodies. Degradation of cellular DNA in nucleosomes was also observed. When two of the amino acids in the catalytic motif of 3C were changed by mutagenesis, the 3C protein not only lost its proteolytic activity, but also its ability to induce apoptosis in the SF268 cells. Twenty-four hours after 3C transfection, poly(ADP-ribose) polymerase, a DNA repair enzyme, was cleaved, indicating that caspases were activated by the expression of EV71 3C. The 3C-induced apoptosis was blocked by the caspase inhibitors DEVD-fmk and VAD-fmk. Our findings suggest that the proteolytic activity of 3C triggers apoptosis in the SF268 cells through a mechanism involving caspase activation and that this apoptotic pathway may play an important role in the pathogenesis of EV71 infection.

Subtyping in concurrency has been extensively studied since early 1990s as one of the most interesting issues in type theory. The correctness of subtyping relations has been usually provided as the soundness for type safety. The converse direction, the completeness, has been largely ignored in spite of its usefulness to define the greatest subtyping relation ensuring type safety. This paper formalises preciseness (i.e. both soundness and completeness) of subtyping for mobile processes and studies it for the synchronous and the asynchronous session calculi. We first prove that the well-known session subtyping, the branching-selection subtyping, is sound and complete for the synchronous calculus. Next we show that in the asynchronous calculus, this subtyping is incomplete for type-safety: that is, there exist session types T and S such that T can safely be considered as a subtype of S, but T S is not derivable by the subtyping. We then propose an asynchronous subtyping system which is sound and complete for the asynchronous calculus. The method gives a general guidance to design rigorous channel-based subtypings respecting desired safety properties.

We describe the first examples of benzoxazine (BZ)linked tetraphenylethylene (TPE)-and pyrene (Py)-containing conjugated microporous organic polymers (CMPs)TPE-TPE-BZ and Py-TPE-BZ, respectivelyhaving high surface areas and pore volumes, prepared through multistep syntheses (Schiff base, reduction, Mannich, and Sonogashira−Hagihara coupling), and their solid-state transformations through ring-opening polymerizations (ROPs) to give BZ linkages have never been reported previously. The chemical structures and, particularly, the presence of BZ units in the TPE-TPE-BZ and Py-TPE-BZ CMPs were confirmed through Fourier transform infrared and solid-state nuclear magnetic resonance spectroscopic analyses. The TEP-TPE-BZ CMP had a high BET specific surface area and a high total pore volume (325 m 2 g −1 and 0.69 cm 3 g −1 , respectively). Because BZ units can undergo ROP through simple thermal treatment without the need for a curing agent or catalyst, the CMPs readily underwent one-step chemical transformations in the solid state to form new CMPs featuring phenolic OH and Mannich bridges as functional groups capable of forming strong intermolecular hydrogen bonds and/or acid/base interactions with molecules of CO 2 gas to enhance the gas uptake ability.

Abstract. In this paper we discuss our ongoing endeavour to apply notations and algorithms based on the π-calculus and its theories for the development of large-scale distributed systems. The execution of a largescale distributed system consists of many structured conversations (or sessions) whose protocols can be clearly and accurately specified using a theory of types for the π-calculus, called session types. The proposed methodology promotes a formally founded, and highly structured, development framework for modelling and building distributed applications, from high-level models to design and implementation to static checking to runtime validation. At the centre of this methodology is a formal description language for representing protocols for interactions, called Scribble. We illustrate the usage and theoretical basis of this language through use cases from different application domains.