Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulti...Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulting in a heightened sensitivity to noradrenaline. In these circumstances, noradrenaline acting on upregulated alpha1 a-adrenoceptors increases the release of cytokine interleukin-6. Hence, nociceptive afferent neurons exposed to injury induced cytokines become more hypersensitive to noradrenaline, which in turn promotes the release of more inflammatory cytokines. Dr. Drummond noted that this mechanism may contribute to the pain of post-herpetic neuralgia or complex regional pain syn- drome （Drummond, 2014）.展开更多
Rubbers have been well accepted for modifying brittle epoxies but rubber modified epoxies usually posses lowered tensile strength though enhanced ductility and fracture resistance. In this work, a polyethylene glycol ...Rubbers have been well accepted for modifying brittle epoxies but rubber modified epoxies usually posses lowered tensile strength though enhanced ductility and fracture resistance. In this work, a polyethylene glycol （PEG-4000） is used to modify diglycidyl ether of bisphenol A/methyltetrahydrophthalic anhydride system for enhancing cryogenic tensile strength, ductility and impact resistance. The results display that the cryogenic tensile strength, ductility （failure strain） and fracture resistance （impact strength） are all enhanced for the modified epoxy system at proper PEG contents. The maximum tensile strength （127.8 MPa） at the cryogenic temperature （77 K） with an improvement of 30.1% is observed for the modified system with the 15 wt% PEG content. The ductility and impact resistance at both room temperature and cryogenic temperature are all improved for the modified epoxy system with proper PEG-4000 contents. These observations are explained by the positron annihilation lifetime spectroscopy results and scanning electron microscopy results. Moreover, the glass transition temperature decreases slightly with increasing PEG content.展开更多
文摘Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulting in a heightened sensitivity to noradrenaline. In these circumstances, noradrenaline acting on upregulated alpha1 a-adrenoceptors increases the release of cytokine interleukin-6. Hence, nociceptive afferent neurons exposed to injury induced cytokines become more hypersensitive to noradrenaline, which in turn promotes the release of more inflammatory cytokines. Dr. Drummond noted that this mechanism may contribute to the pain of post-herpetic neuralgia or complex regional pain syn- drome （Drummond, 2014）.
基金support of the National Natural Science Foundation of China(Nos. 51073169,10972216 and 11002141)
文摘Rubbers have been well accepted for modifying brittle epoxies but rubber modified epoxies usually posses lowered tensile strength though enhanced ductility and fracture resistance. In this work, a polyethylene glycol （PEG-4000） is used to modify diglycidyl ether of bisphenol A/methyltetrahydrophthalic anhydride system for enhancing cryogenic tensile strength, ductility and impact resistance. The results display that the cryogenic tensile strength, ductility （failure strain） and fracture resistance （impact strength） are all enhanced for the modified epoxy system at proper PEG contents. The maximum tensile strength （127.8 MPa） at the cryogenic temperature （77 K） with an improvement of 30.1% is observed for the modified system with the 15 wt% PEG content. The ductility and impact resistance at both room temperature and cryogenic temperature are all improved for the modified epoxy system with proper PEG-4000 contents. These observations are explained by the positron annihilation lifetime spectroscopy results and scanning electron microscopy results. Moreover, the glass transition temperature decreases slightly with increasing PEG content.
