A convenient one-pot synthesis of chelating bis-N-heterocyclic carbene-ligated P(I) salts is described. The solid state structures of these remarkably stable phosphamethine cyanine dyes with various N-alkyl groups and counter-anions are reported, and initial reactivity results are discussed.

SUMMARY Innate immunity controls pathogen replication and spread. Yet, certain pathogens, such as Hepatitis C Virus (HCV), escape immune elimination and establish persistent infections that promote chronic inflammation and related diseases. Whereas HCV regulatory proteins that attenuate anti-viral responses are known, those that promote inflammation and liver injury remain to be identified. Here we describe that transient expression of HCV RNA-dependent RNA polymerase (RdRp), NS5B, in mouse liver and human hepatocytes results in production of small RNA species that activate innate immune signaling via TBK1-IRF3 and NF-κB and induce cytokine production including type I interferons (IFN) and IL-6. NS5B-expression also results in liver damage.

Structural weight reduction and high aspect ratio wings play a key role in improving the performance of modern transport aircraft. This leads to a highly flexible aircraft structure which is sensitive to external disturbances like gusts. To counteract this undesired effect, active control is a promising technology. In this paper, a gust load alleviation controller is designed for a wind tunnel model of a flexible wing with various trailing edge flaps and acceleration sensors. For a sophisticated model-based controller design, a detailed aeroelastic model is derived describing the coupling of structural dynamics and aerodynamics. Additionally, actuator dynamics and structural modes are identified and used to improve model accuracy. Subsequently, the weakly damped first wing bending mode, which causes high structural loads, is isolated via H 2-optimal blending of control inputs and measurement outputs. In this way, a gain-scheduled single-input single-output controller can be designed to control the desired aeroelastic mode. Eventually, the great potential of the proposed control approach is verified by a wind tunnel test including different gust excitations and varying airspeeds.

In this paper, the effect of nonlinear actuator dynamics on the performance of an active load alleviation system for an experimental flexible wing is studied. Common nonlinearities such as backlash or rate limits are considered for the control surface actuator. An aeroelastic simulation model of a flexible wing with control surface is being used. With this, a parameter study is carried out to quantify the impact of the individual nonlinearities on the overall closed-loop performance by means of describing functions. Finally, the nonlinear actuator model with parameters identified from dedicated tests is experimentally validated allowing for an accurate prediction of the expected gust load alleviation performance.