Different protein expression patterns in rat spinal nerves during wallerian degeneration assessed using isobaric tags for relative and absolute quantitation proteomics profiling

Sensory and motor nerve fibers of peripheral nerves have different anatomies and regeneration functions after injury. To gain a clear understanding of the biological processes behind these differences, we used a labeling technique termed isobaric tags for relative and absolute quantitation to investigate the protein profiles of spinal nerve tissues from Sprague-Dawley rats. In response to Wallerian degeneration, a total of 626 proteins were screened in sensory nerves, of which 368 were upregulated and 258 were downregulated. In addition, 637 proteins were screened in motor nerves, of which 372 were upregulated and 265 were downregulated. All identified proteins were analyzed using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of bioinformatics, and the presence of several key proteins closely related to Wallerian degeneration were tested and verified using quantitative real-time polymerase chain reaction analyses. The differentially expressed proteins only identified in the sensory nerves were mainly relevant to various biological processes that included cell-cell adhesion, carbohydrate metabolic processes and cell adhesion, whereas differentially expressed proteins only identified in the motor nerves were mainly relevant to biological processes associated with the glycolytic process, cell redox homeostasis, and protein folding. In the aspect of the cellular component, the differentially expressed proteins in the sensory and motor nerves were commonly related to extracellular exosomes, the myelin sheath, and focal adhesion. According to the Kyoto Encyclopedia of Genes and Genomes, the differentially expressed proteins identified are primarily related to various types of metabolic pathways. In conclusion, the present study screened differentially expressed proteins to reveal more about the differences and similarities between sensory and motor nerves during Wallerian degeneration. The present findings could provide a reference point for a future investigation into the differences between sensory and motor nerves in Wallerian degeneration and the characteristics of peripheral nerve regeneration. The study was approved by the Ethics Committee of the Chinese PLA General Hospital, China(approval No. 2016-x9-07) in September 2016.

Optimization of the S-band side-coupled cavities for proton acceleration

The proton beam with energy around 100 MeV has seen wide applications in modern scientific research and in various fields.However,proton sources in China fall short for meeting experimental needs owing to the vast size and expensive traditional proton accelerators.The Institute of Nuclear Science and Technology of Sichuan University proposed to build a 3 GHz side-coupled cavity linac(SCL)for re-accelerating a 26 MeV proton beam extracted from a CS-30 cyclotron to 120 MeV.We carried out investigations into several vital factors of S-band SCL for proton acceleration,such as optimization of SCL cavity geometry,end cell tuning,and bridge coupler design.Results demonstrated that the effective shunt impedance per unit length ranged from 22.5 to 59.8 MX/m throughout the acceleration process,and the acceleration gradient changed from 11.5 to 15.7 MV/m when the maximum surface electric field was equivalent to Kilpatrick electric field.We obtained equivalent circuit parameters of the biperiodic structures and applied them to the end cell tuning;results of the theoretical analysis agreed well with the 3D simulation.We designed and optimized a bridge coupler based on the previously obtained biperiodic structure parameters,and the field distribution un-uniformness was\1.5%for a two-tank module.The radio frequency power distribution system of the linac was obtained based on the preliminary beam dynamics design.