Objective To determine the effects of non-thermal biological effect of low frequency pulsed electromagnetic field (LFPEF) with 15 Hz and 30 mT on ulcer wound during the plateau stress ulcer cure.Methods Thirty male Sprague-Dawley rats were assigned to three equal groups:control,normal cure group (NC) and exposure treatment groups (ET).The plateau rats stress ulcer models were constructed with the combination method of a hypoxic and low-pressure acclimation and the stimulation of absolute ethyl alcohol irrigating stomach.The LFPEF equipment generated the LFPEF of 15 Hz,40％ duty cycle and 30 mT to expose and treat the rats' stomach of ET group with the frequency of 3 hours each day.After 6 days of exposure treatment,the stress ulcer cure situation of each group was evaluated by the methods of macroscopic observation,the gastric juice pH values detection and ulcer index (UI) measurement.Results After 6 days of model,the macroscopic observation showed that the ulcer of NC group was worse than the that of ET group (P＜0.05).The pH values and UI of ET group were significantly different with those of NC group,and closed to those of the control group.Conclusion The nonthermal biological effect of LFPEF could promote the plateau stress ulcer cure.

Objective To determine the difference in blood microcirculation recovery between normal frostbite and high-altitude frostbite during the wound healing.Methods Twenty four male rats were randomly divided into control group (n=8), normal frostbite group (n=8), and high-altitude group (n=8). The normal frostbite group rats were frozen to produce mid-degree frostbite models by controlling the freezing time with liquid nitrogen penetration equipment. The high-altitude frostbite group rats were acclimated to a hypoxic and low-pressure environment for 1 week, and then the high-altitude frostbite models were constructed by the same way with liquid nitrogen penetration apparatus. On days 3, 7, 11, 15, 19, and 23 after modeling, the recovery situation of blood circulation of each group was observed with contrast ultrasonography by injecting SonoVue micro-bubble into rats' tail. Finally, the micro-bubble concentration (MC) was calculated to confirm the blood circulation recovery with software Image Pro. ResultsAt different time points, the wound area of the high-altitude frostbite group was bigger than that of the normal frostbite group, and the MC of control group was always about (27±0.2)×109/ml. On day 3, 7, 11, 15, 19, and 23, the MC was significantly lower in the high-altitude frostbite group than in the control group and normal frostbite group (P<0.05). The MC of normal frostbite group was significantly lower than that of the control group on day 3, 7, 11, 15 and 19 (P<0.05). In addition, no obvious difference in MC was found between normal group and control group on the 23th day (P<0.05).Conclusion The blood microcirculation recovery after high-altitude frostbite is significantly slower than the normal frostbite.