Background Cold environments reduce work efficiency and increase the risk of frostbite. Objective To investigate the effects on cold protection and manual performance of rescue gloves in cold environments, and to preliminarily verify the feasibility of related quantitative characterization methods. Methods An experiment was conducted in a large and a small artificial climate chamber. 12 male right-handed university students were recruited. The experiment was divided into two parts, with 0-10 min as the baseline phase and 10-50 min as the test phase. Subjects sat quietly in a 16 ℃ large chamber, and hands were exposed to a small chamber at 0 ℃ either barely (control group) or with rescue gloves (experimental group). Skin temperatures of the five fingers (thumb, index finger, middle finger, ring finger, and little finger), as well as the dorsal and palm of the hands were measured. In addition, grip strength, manual dexterity, maximum finger flexion, and tactile sensitivity of the hands were measured as the indicators of manual performance. Results In the control group, cold-induced vasodilation occurred when the skin temperature of the five fingers were lowered to about 10 ℃. The maximum rate of change in skin temperature of the control group was in the following order: thumb＞index finger＞middle finger＞little finger＞ring finger＞dorsal＞palm, 165.7 ℃·h⁻¹ in the thumb, 80.0 and 89.9 ℃·h⁻¹ in the palm and dorsal respectively. In addition, the minimum skin temperature of the thumb was 6.6 ℃. Compared with the control group: the rate of change of skin temperature in the experimentalgroup decreased by about 50%; the grip strength decreased by 15% after wearing the rescue gloves (P<0.05); no differences in manual dexterity, maximum finger flexion, and tactile sensitivity were statistically significant (P>0.05). Conclusion This study proved that the rescue gloves improved the thermal comfort of hands while better balancing the effect of cold exposure on manual performance. The quantitative characterization methods can evaluate the protective performance and manual performance of the rescue gloves, which provides a reliable theoretical foundation and reference basis for further experiments.

Aortic dissection is a common disease which is very dangerous,with high mortality rate.Bypass graft for the treatment of DeBakey Ⅲ dissection has outstanding advantages than the ordinary replacement of thoracic aorta,and some patients will inevitably require the use of the procedure.The purpose of this study was to explore the impact of the subclavian artery-abdominal aorta bypass graft on hemodynamic parameters in the false lumen and the effectiveness of surgical treatment.First of all,the idealized three-dimensional geometric models of DeBakey Ⅲ aortic dissection and its subclavian artery-abdominal aorta bypass graft operation were constructed,respectively.Then the models were imported into ANSYS 11.0 for finite element analysis.Results of numerical simulation showed that both velocity and pressure of the blood flow were reduced after bypass graft at the entrance and in the internal sac of false lumen,which is very favorable for reducing the impact of blood flow on false lumen,slowing down the further expansion of entrance,preventing the breakdown of false lumen,and promoting the healing of dissection.Therefore,the subclavian artery-abdominal aorta bypass graft operation is an effective surgical method for the treatment of DeBakey Ⅲ aortic dissection in some particular cases.This operation is with great prospects for clinical application.