Development of a monochromatic crystal backlight imager for the recent double-cone ignition experiments

We developed a monochromatic crystal backlight imaging system for the double-cone ignition(DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and temporal evolution of the head-on colliding plasma from the two compressing cones in the DCI experiments. The influence of laser parameters on the x-ray backlighter intensity and spatial resolution of the imaging system was investigated. The imaging system had a spatial resolution of 10 μm when employing a CCD detector. Experiments demonstrated that the system can obtain time-resolved radiographic images with high quality, enabling the precise measurement of the shape, size, and density distribution of the plasma.

double-cone ignition;streaked optical pyrometer;velocity interferometer system for any reflector

The velocity interferometer system for any reflector(VISAR) coupled with a streaked optical pyrometer(SOP) system is used as a diagnostic tool in inertial confinement fusion(ICF) experiments involving equations of state and shock timing.To validate the process of adiabatically compressing the fuel shell through precise tuning of shocks in experimental campaigns for the double-cone ignition(DCI) scheme of ICF, a compact line-imaging VISAR with an SOP system is designed and implemented at the Shenguang-II upgrade laser facility. The temporal and spatial resolutions of the system are better than 30 ps and 7 μm, respectively. An illumination lens is used to adjust the lighting spot size matching with the target size. A polarization beam splitter and λ/4 waveplate are used to increase the transmission efficiency of our system. The VISAR and SOP work at 660 and 450 nm, respectively, to differentiate the signals from the scattered lights of the drive lasers. The VISAR can measure the shock velocity. At the same time, the SOP system can give the shock timing and relative strength. This system has been used in different DCI campaigns, where the generation and propagation processes of multi-shock are carefully diagnosed.

A reactive oxygen species-responsive hydrogel encapsulated with bone marrow derived stem cells promotes repair and regeneration of spinal cord injury

Spinal cord injury(SCI)is an overwhelming and incurable disabling event accompanied by complicated inflammation-related pathological processes,such as excessive reactive oxygen species(ROS)produced by the infiltrated inflammatory immune cells and released to the extracellular microenvironment,leading to the widespread apoptosis of the neuron cells,glial and oligodendroctyes.In this study,a thioketal-containing and ROS-scavenging hydrogel was prepared for encapsulation of the bone marrow derived mesenchymal stem cells(BMSCs),which promoted the neurogenesis and axon regeneration by scavenging the overproduced ROS and re-building a regenerative microenvironment.The hydrogel could effectively encapsulate BMSCs,and played a remarkable neuroprotective role in vivo by reducing the production of endogenous ROS,attenuating ROS-mediated oxidative damage and downregulating the inflammatory cytokines such as interleukin-1 beta(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-alpha(TNF-α),resulting in a reduced cell apoptosis in the spinal cord tissue.The BMSCs-encapsulated ROS-scavenging hydrogel also reduced the scar formation,and improved the neurogenesis of the spinal cord tissue,and thus distinctly enhanced the motor functional recovery of SCI rats.Our work provides a combinational strategy against ROS-mediated oxidative stress,with potential applications not only in SCI,but also in other central nervous system diseases with similar pathological conditions.