Objective To explore the effect of moxibustion at Shenque （神阙 CV 8） on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided int...Objective To explore the effect of moxibustion at Shenque （神阙 CV 8） on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided into 3 groups according to the random number table method, including blank group, model group and moxibustion group. The model group and moxibustion group were divided into 4 subgroups respectively, that was 1 time, 4 times, 7 times and 10 times subgroup. There were 9 groups with 8 rats in each group. Except blank group, all the rats were established into exhaustive models through swimming. Mild moxibustion at CV 8 was carried out for 15 min in the rats in moxibustion group after modeling for once every other day. The concentration of serum glucose （GLU）, malonaldehyde （MDA） and blood urea nitrogen （BUN） as well as the activity of aspartate transaminase （AST）, alanine transaminase （ALT） and lactic dehydrogenase （LDH） were detected 24h after the exhaustive exercise by adopting full-automatic analyzer. Results The exhaustive time of rats were long at first but shorter later. The exhaustive time of rats in the model group （4 times） were obviously longer than that in the model group （1 time） （P〈0.01）, the exhaustive time of rats in the model group （7 times） and model group （10 times） were obviously shorter than that in the model group （1 time） （P〈0.01）, and the exhaustive time of rats in the moxibustion group （7 times） and moxibustion group （10 times） were obviously longer than that in the model group with the same number of times （P〈0.01）, the serum GLU level of rats in the model group （7 times） and model group （10 times） increased when compared with the blank group （P〈0.01）, and the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of rats in the model group （4 times）, model group （7 times） and model group （10 times） increased when compared with the blank group （P〈0.05 or P〈0.01）, the serum GLU, MDA and BNU levels as well as the activity of AST and ALT of rats in the moxibustion group （7 times） and moxibustion group （10 times） reduced when compared with the model group with the same number of times （P〈0.05 or P〈0.01）, and the serum LDH activity of rats in the moxibustion group （4 times）, moxibustion group （7 times） and moxibustion group （10 times） reduced when compared with the model group with the same number of times （P〈0.05 or P〈0.01）. Conclusion Moxibustion at CV 8 can reduce the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of organism in a status of long-term fatigue, effectively improve the symptom of long-term fatigue, providing a certain experimental basis for the clinical application of moxibustion at CV 8 in the process of anti-exercise-induced fatigue in the future.展开更多
It is well known that metallic materials exhibit worse fatigue damage tolerance as they behave stronger in strength and softer in modulus. This raises concern on the long term safety of the recently developed biomecha...It is well known that metallic materials exhibit worse fatigue damage tolerance as they behave stronger in strength and softer in modulus. This raises concern on the long term safety of the recently developed biomechanical compatible titanium alloys with high strength and low modulus. Here we demonstrate via a model alloy, Ti-24 Nb-4 Zr-8 Sn in weight percent, that this group of multifunctional titanium alloys possessing nonlinear elastic deformation behavior is tolerant in fatigue notch damage. The results reveal that the alloy has a high strength-to-modulus（σ/E） ratio reaching2% but its fatigue notch sensitivity（q） is low, which decreases linearly from 0.45 to 0.25 as stress concentration factor increases from 2 to 4. This exceeds significantly the typical relationship between σ/E and q of other metallic materials exhibiting linear elasticity. Furthermore, fatigue damage is characterized by an extremely deflected mountain-shape fracture surface, resulting in much longer and more tortuous crack growth path as compared to these linear elastic materials. The above phenomena can be explained by the nonlinear elasticity and its induced stress relief at the notch root in an adaptive manner of higher stress stronger relief. This finding provides a new strategy to balance high strength and good damage tolerance property of metallic materials.展开更多
基金Supported by Natural Science Fund Project of Youth of Hebei Education Department:QN2016021Key Scientific Project of Administration of Traditional Chinese Medicine of Hebei Province:2016011 and 2017011
文摘Objective To explore the effect of moxibustion at Shenque （神阙 CV 8） on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided into 3 groups according to the random number table method, including blank group, model group and moxibustion group. The model group and moxibustion group were divided into 4 subgroups respectively, that was 1 time, 4 times, 7 times and 10 times subgroup. There were 9 groups with 8 rats in each group. Except blank group, all the rats were established into exhaustive models through swimming. Mild moxibustion at CV 8 was carried out for 15 min in the rats in moxibustion group after modeling for once every other day. The concentration of serum glucose （GLU）, malonaldehyde （MDA） and blood urea nitrogen （BUN） as well as the activity of aspartate transaminase （AST）, alanine transaminase （ALT） and lactic dehydrogenase （LDH） were detected 24h after the exhaustive exercise by adopting full-automatic analyzer. Results The exhaustive time of rats were long at first but shorter later. The exhaustive time of rats in the model group （4 times） were obviously longer than that in the model group （1 time） （P〈0.01）, the exhaustive time of rats in the model group （7 times） and model group （10 times） were obviously shorter than that in the model group （1 time） （P〈0.01）, and the exhaustive time of rats in the moxibustion group （7 times） and moxibustion group （10 times） were obviously longer than that in the model group with the same number of times （P〈0.01）, the serum GLU level of rats in the model group （7 times） and model group （10 times） increased when compared with the blank group （P〈0.01）, and the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of rats in the model group （4 times）, model group （7 times） and model group （10 times） increased when compared with the blank group （P〈0.05 or P〈0.01）, the serum GLU, MDA and BNU levels as well as the activity of AST and ALT of rats in the moxibustion group （7 times） and moxibustion group （10 times） reduced when compared with the model group with the same number of times （P〈0.05 or P〈0.01）, and the serum LDH activity of rats in the moxibustion group （4 times）, moxibustion group （7 times） and moxibustion group （10 times） reduced when compared with the model group with the same number of times （P〈0.05 or P〈0.01）. Conclusion Moxibustion at CV 8 can reduce the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of organism in a status of long-term fatigue, effectively improve the symptom of long-term fatigue, providing a certain experimental basis for the clinical application of moxibustion at CV 8 in the process of anti-exercise-induced fatigue in the future.
基金supported by the National Key Research and Development Program of China (2016YFC1102601 and 2017YFC1104901)the National Natural Science Foundation of China (51571190 and 51631007)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences (QYZDJ-SSW-JSC031)
文摘It is well known that metallic materials exhibit worse fatigue damage tolerance as they behave stronger in strength and softer in modulus. This raises concern on the long term safety of the recently developed biomechanical compatible titanium alloys with high strength and low modulus. Here we demonstrate via a model alloy, Ti-24 Nb-4 Zr-8 Sn in weight percent, that this group of multifunctional titanium alloys possessing nonlinear elastic deformation behavior is tolerant in fatigue notch damage. The results reveal that the alloy has a high strength-to-modulus（σ/E） ratio reaching2% but its fatigue notch sensitivity（q） is low, which decreases linearly from 0.45 to 0.25 as stress concentration factor increases from 2 to 4. This exceeds significantly the typical relationship between σ/E and q of other metallic materials exhibiting linear elasticity. Furthermore, fatigue damage is characterized by an extremely deflected mountain-shape fracture surface, resulting in much longer and more tortuous crack growth path as compared to these linear elastic materials. The above phenomena can be explained by the nonlinear elasticity and its induced stress relief at the notch root in an adaptive manner of higher stress stronger relief. This finding provides a new strategy to balance high strength and good damage tolerance property of metallic materials.
