Comparative study on Photobiomodulation between 630 nm and 810 nm LED in diabetic wound healing both in vitro and in vivo

Photobiomodulation(PBM)promoting wound healing has been demonstrated by many studies.Currently,630 nm and 810 nm light-emitting diodes(LEDs),as light sources,are frequently used in the treatment of diabetic foot ulcers(DFUs)in clinics.However,the dose-effect relationship of LED-mediated PBM is not fully understood.Furthermore,among the 630 nm and 810 nm LEDs,which one gets a better effect on accelerating the wound healing of diabetic ulcers is not clear.The aim of this study is to evaluate and compare the effects of 630 nm and 810 nm LED-mediated PBM in wound healing both in vitro and in vivo.Our results showed that both 630 nm and 810 nm LED irradiation significantly promoted the proliferation of mouse fibroblast cells(L929)at different light irradiances(1,5,and 10 mW/cm^(2)).The cell proliferation rate increased with the extension of irradiation time(100,200,and 500 s),but it decreased when the irradiation time was over 500 s.Both 630 nm and 810nm LED irradiation(5 mW/cm^(2))significantly improved the migration capability of L929 cells.No difference between 630 nm and 810 nm LED-mediated PBM in promoting cell proliferation and migration was detected.In vivo results presented that both 630 nm and 810 nm LED irradiation promoted the wound healing and the expression of the vascular endothelial growth factor(VEGF)and transforming growth factor(TGF)in the wounded skin of type 2 diabetic mice.Overall,these results suggested that LED-mediated PBM promotes wound healing of diabetic mice through promoting fibroblast cell proliferation,migration,and the expression of growth factors in the wounded skin.LEDs(630 nm and 810 nm)have a similar outcome in promoting wound healing of type 2 diabetic mice.

Application and Analysis of Advanced Manufacturing Technology in Track Equipment Manufacturing Industry

With the rapid development of global transportation track equipment, the running speed of modern rail transit equipment keeps refreshing records. High-speed EMUs, inter-city EMUs and urban rail vehicles have become the main types of domestic passenger transport vehicles, especially the lightweight production and manufacture of high-speed EMUs and urban rail vehicles, which are the main topics of railway transport modernization research and discussion. Track manufacturing is a successful example of China's industrial transformation and strategic restructuring through systematic innovation since the reform and opening up. In this paper, the application of some advanced manufacturing technologies in the track equipment manufacturing industry and the opportunities and challenges faced by the whole track equipment manufacturing industry were mainly studied, hoping to provide some help for the development of the track equipment manufacturing industry in China.

Achieving Superior Superplasticity in a Mg-6Al-Zn Plate via Multi-pass Submerged Friction Stir Processing

A large-scale Mg-6Al-Zn plate was prepared by multi-pass submerged friction stir processing(M-SFSP)and its superplastic deformation behavior was investigated.The maximum elongation of 467%,332%and 421%was attained for the samples oriented in the processing direction(PD),45°tilted toward the PD,and transverse direction(TD),respectively,when deformed at 623 K and a strain rate of 1×10^(−3) s^(−1).This was attributed to the homogeneous and fine-grained structure with mostly high-angle grain boundaries facilitating the prevalent deformation mechanism of grain boundary sliding,along with the weakened texture and dynamic recrystallization during hot deformation.