Argon plasma-pretreated poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films were subjected to UV-induced surface graft copolymerization with acrylonitrile (AN). The AN graft-copolymerized FEP (AN-g-FEP) surface was further reacted with hydroxylamine to introduce amidoxime groups on the surface (the amidoximated AN-g-FEP surface). Electroless plating of copper could be carried out effectively on the AN-g-FEP and amidoximated AN-g-FEP surfaces after sensitization in SnCl2 solution and activation in PdCl2 solution. The plasma pretreatment time of the FEP substrate and the UV graft copolymerization time affected the graft concentration of the AN polymer on the FEP surface. The surface compositions and the degree of amidoximation (DA) of the surface-modified FEP films were determined by X-ray photoelectron spectroscopy (XPS). The amidoximated FEP surface formed a complex with palladium ions and exhibited a strong ability to extract copper ions from the plating solution. The interaction of the AN-g-FEP and its amidoximated surfaces with evaporated copper atoms was investigated in situ by XPS. The T-peel adhesion strength of the electrolessly deposited copper with the amidoximated AN-g-FEP surface was enhanced to about 12 N/cm, from about 5 N/cm with the AN-g-FEP surface. The adhesion failure of the electrolessly deposited copper with the amidoximated AN-g-FEP film occurred cohesively inside the FEP substrate.

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The changes of endogenous Fas/FasL in injured spinal cord, mostly in primates, are not well known. In this study, we investigated the temporal changes in the expression of Fas and FasL and explored their possible roles in the ventral horn of the spinal cord and associated precentral gyrus following T(11) spinal cord hemisection in the adult rhesus monkey. A significant functional improvement was seen with the time going on in monkeys subjected to cord hemisection. Apoptotic cells were also seen in the ventral horn of injured spinal cord with TUNEL staining, and a marked increase presents at 7 days post operation (dpo). Simultaneously, the number of Fas and FasL immunoreactive neurons in the spinal cords caudal and rostral to injury site and their intracellular optical density (OD) in the ipsilateral side of injury site at 7 dpo increased significantly more than that of control group and contralateral sides. This was followed by a decrease and returned to normal level at 60 dpo. No positive neurons were observed in precentral gyrus. The present results may provide some insights to understand the role of Fas/FasL in the spinal cord but not motor cortex with neuronal apoptosis and neuroplasticity in monkeys subjected to hemisection spinal cord injury.

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