Background: Testicular atrophy is recurrent after orchidopexy for intra-abdominal cryptorchidism due to damage to vessels. Fowlers-Stephens and Shehata methods proposed staged orchidopexy, but are still associated to ...Background: Testicular atrophy is recurrent after orchidopexy for intra-abdominal cryptorchidism due to damage to vessels. Fowlers-Stephens and Shehata methods proposed staged orchidopexy, but are still associated to a rate of atrophy greater than 10%. Purpose: We set out to present a new technique that preserves testicular vessels. Our study is aimed at investigating testicular vitality after surgery. Patients and Method: We reviewed files of boys who underwent orchidopexy for 2 years in our department. Those who have been operated for intra-abdominal cryptorchidism with the new technique and aged between 6 months and 14 years old were included in our study. We excluded boys who have been operated before 6 months and after 14 years old and those who did not respect their follow-up plane. Ultrasound (US) outcomes were used to measure testicular volumes and blood flow at each postoperative visit. The Sample population was divided into group A and group B representing testes that were followed respectively for 12 and 24 months. Results: 22 boys with 25 testes were included in our study;11 testes in group A and 14 testes in group B. In each group, we noted a significant difference of UDT volumes from the third month after surgery with respective P-values 0.05. There was no statistical difference between UDT and contra lateral testes volumes 12 months after surgery in group A and 24 months in group B with respective P-values of 0.07 and 0.72. All volume differential indexes were Conclusion: This method offers a new perspective in performing safe orchidopexy for intra abdominal undescended testes.展开更多
【目的】牧草太空育种是近三十年来新兴的一种育种技术,具有变异多、变幅大、稳定快等特点,可缩短牧草育种周期。本文综述了太空育种的研究现状,分析总结了太空育种的原理、方法及可能存在的问题,以期为今后牧草太空育种提供更多参考和...【目的】牧草太空育种是近三十年来新兴的一种育种技术,具有变异多、变幅大、稳定快等特点,可缩短牧草育种周期。本文综述了太空育种的研究现状,分析总结了太空育种的原理、方法及可能存在的问题,以期为今后牧草太空育种提供更多参考和启发。【方法】通过Web of Science、Google Scholar、中国知网、百度学术等网站查阅了大量太空育种尤其是牧草太空育种的相关文献,并对文献资料进行收集、分析和整理。【结果】太空环境诱变是当今牧草育种重要发展方向之一,通过总结太空诱变技术在牧草育种中的应用,分析了牧草太空育种中面临的问题和挑战,展望了采用太空环境诱变创制牧草新品种的前景。【结论】太空环境诱变能诱发牧草基因组中的突变,增加其遗传多样性,从而创造出具有新特性的植物品种,对牧草类作物进行种质资源的创制具有重大意义,同时也为快速培育优良牧草新品种及特异种质资源开辟了一条新途径。太空育种技术为牧草育种开辟了新的可能性,有望成为未来太空农业的重要组成部分。展开更多
BACKGROUND Developing methods to monitor exercise load and evaluate body fatigue and muscle injury over time in hiking training remains a key problem to be solved.A widely used psycho-physical tool to assess the subje...BACKGROUND Developing methods to monitor exercise load and evaluate body fatigue and muscle injury over time in hiking training remains a key problem to be solved.A widely used psycho-physical tool to assess the subjective perception of effort during exercise is Borg’s rating of perceived exertion(BRPE)scale.Data on the relationships and validity of the BRPE compared to objectively assessed metabolic criteria are still lacking,especially urinary organic acid concentrations.AIM To verify whether the BRPE scale could be used in the prescription of outdoor hiking with weight-bearing and reveal the relationship between the BRPE scale and urinary physiological measures.METHODS Eighty-nine healthy men(average age:22 years)were enrolled in a 40 km(6 h)hiking training exercise with a 20 kg load.After training,the BRPE scale(6-20)was completed.All participants were divided into three groups according to the rating of the BRPE scale.Urine samples were collected before and after training.Urinary myoglobin levels were measured immediately using the fluorescent immunoassay method.The remaining urine was subpacked and frozen for the subsequent detection of urinary organic acids using gas chromatography and mass spectrometry.RESULTS The contents of organic acids and myoglobin in urine were significantly increased after participants hiked 40 km(6 h)with a 20 kg load.Only orthogonal partial least-squares discrimination analysis performed well in separating the group with a BRPE score of 6-12 from the group with a BRPE score of 13-20.Significant differences in the urine levels of several organic acids were observed between the two groups,and the heatmap also presented different metabolic profiles based on BRPE.According to the standard of a variable importance in the projection>1,fold change>1.5 and P<0.05,19 different metabolites of urinary organic acids were screened and enriched in pathways mainly including the citrate cycle(tricarboxylic acid cycle)and alanine,aspartate and glucose metabolism.CONCLUSION The BRPE scale identified significantly different urinary organic acid profiles between the higher and lower BRPE value groups,and,thus,could be used to monitor body fatigue in individuals participating in long-distance outdoor hiking with weight bearing.展开更多
文摘Background: Testicular atrophy is recurrent after orchidopexy for intra-abdominal cryptorchidism due to damage to vessels. Fowlers-Stephens and Shehata methods proposed staged orchidopexy, but are still associated to a rate of atrophy greater than 10%. Purpose: We set out to present a new technique that preserves testicular vessels. Our study is aimed at investigating testicular vitality after surgery. Patients and Method: We reviewed files of boys who underwent orchidopexy for 2 years in our department. Those who have been operated for intra-abdominal cryptorchidism with the new technique and aged between 6 months and 14 years old were included in our study. We excluded boys who have been operated before 6 months and after 14 years old and those who did not respect their follow-up plane. Ultrasound (US) outcomes were used to measure testicular volumes and blood flow at each postoperative visit. The Sample population was divided into group A and group B representing testes that were followed respectively for 12 and 24 months. Results: 22 boys with 25 testes were included in our study;11 testes in group A and 14 testes in group B. In each group, we noted a significant difference of UDT volumes from the third month after surgery with respective P-values 0.05. There was no statistical difference between UDT and contra lateral testes volumes 12 months after surgery in group A and 24 months in group B with respective P-values of 0.07 and 0.72. All volume differential indexes were Conclusion: This method offers a new perspective in performing safe orchidopexy for intra abdominal undescended testes.
文摘【目的】牧草太空育种是近三十年来新兴的一种育种技术,具有变异多、变幅大、稳定快等特点,可缩短牧草育种周期。本文综述了太空育种的研究现状,分析总结了太空育种的原理、方法及可能存在的问题,以期为今后牧草太空育种提供更多参考和启发。【方法】通过Web of Science、Google Scholar、中国知网、百度学术等网站查阅了大量太空育种尤其是牧草太空育种的相关文献,并对文献资料进行收集、分析和整理。【结果】太空环境诱变是当今牧草育种重要发展方向之一,通过总结太空诱变技术在牧草育种中的应用,分析了牧草太空育种中面临的问题和挑战,展望了采用太空环境诱变创制牧草新品种的前景。【结论】太空环境诱变能诱发牧草基因组中的突变,增加其遗传多样性,从而创造出具有新特性的植物品种,对牧草类作物进行种质资源的创制具有重大意义,同时也为快速培育优良牧草新品种及特异种质资源开辟了一条新途径。太空育种技术为牧草育种开辟了新的可能性,有望成为未来太空农业的重要组成部分。
文摘工程结构在制造工艺过程中或使用期间会产生裂纹,对结构断裂路径的预测和研究是防治工程安全问题发生的重要手段。在考虑裂纹尖端应力场常数项T应力的基础上对传统的最大周向应力准则(Maximum tangential stress criterion,MTS)和最小应变能密度因子准则(Minimum strain energy density criterion,SED)进行修正,采用Python语言对ABAQUS的前、后处理和有限元计算模块进行二次开发,通过计算最优解的粒子群算法(Particle swarm optimization,PSO)将修正后的准则编入裂纹自动扩展程序脚本中。利用上述二次开发程序对初始纯Ⅰ型裂纹的扩展路径进行模拟,结果表明:采用ABAQUS脚本程序模拟结果与相关文献实验结果吻合,表明了程序的有效性,进而实现考虑T应力的多种断裂准则对裂纹扩展路径的预测;当T应力值处于一定范围内时,修正的MTS准则无法预测裂纹发生的偏转现象,扩展路径呈直线,此时可采用修正的SED准则进行预测。
基金the National Key Research and Development Program of China,No.2020YFC2004604,2020YFC2002700。
文摘BACKGROUND Developing methods to monitor exercise load and evaluate body fatigue and muscle injury over time in hiking training remains a key problem to be solved.A widely used psycho-physical tool to assess the subjective perception of effort during exercise is Borg’s rating of perceived exertion(BRPE)scale.Data on the relationships and validity of the BRPE compared to objectively assessed metabolic criteria are still lacking,especially urinary organic acid concentrations.AIM To verify whether the BRPE scale could be used in the prescription of outdoor hiking with weight-bearing and reveal the relationship between the BRPE scale and urinary physiological measures.METHODS Eighty-nine healthy men(average age:22 years)were enrolled in a 40 km(6 h)hiking training exercise with a 20 kg load.After training,the BRPE scale(6-20)was completed.All participants were divided into three groups according to the rating of the BRPE scale.Urine samples were collected before and after training.Urinary myoglobin levels were measured immediately using the fluorescent immunoassay method.The remaining urine was subpacked and frozen for the subsequent detection of urinary organic acids using gas chromatography and mass spectrometry.RESULTS The contents of organic acids and myoglobin in urine were significantly increased after participants hiked 40 km(6 h)with a 20 kg load.Only orthogonal partial least-squares discrimination analysis performed well in separating the group with a BRPE score of 6-12 from the group with a BRPE score of 13-20.Significant differences in the urine levels of several organic acids were observed between the two groups,and the heatmap also presented different metabolic profiles based on BRPE.According to the standard of a variable importance in the projection>1,fold change>1.5 and P<0.05,19 different metabolites of urinary organic acids were screened and enriched in pathways mainly including the citrate cycle(tricarboxylic acid cycle)and alanine,aspartate and glucose metabolism.CONCLUSION The BRPE scale identified significantly different urinary organic acid profiles between the higher and lower BRPE value groups,and,thus,could be used to monitor body fatigue in individuals participating in long-distance outdoor hiking with weight bearing.
