Cuprous oxide(Cu_(2)O) is one of the most promising catalysts for electrochemical conversion of CO_(2) into value-added C_(2) products.The efficiency of CO_(2)-to-C_(2) conversion is highly dependent on the Cu_(2)O cr...Cuprous oxide(Cu_(2)O) is one of the most promising catalysts for electrochemical conversion of CO_(2) into value-added C_(2) products.The efficiency of CO_(2)-to-C_(2) conversion is highly dependent on the Cu_(2)O crystal plane orientation and the corresponding adsorbed ^(*)CO species.Herein,we constructed high-index crystal planes(311) in Cu_(2)O(CO-Cu_(2)O) via a facile self-selective CO-induced strategy under a CO atmosphere,which was verified by high-resolution transmission electron microscopy(HR-TEM) and atomic force microscopy(AFM) results.By exploiting the high surface energy of the high index crystal planes,^(*)CO species are stabilized in CO-Cu_(2)O during CO_(2)RR,resulting in exceptional catalytic performance for CO_(2)-to-C_(2)products.In situ infrared spectroscopy revealed that both atop-type(^(*)CO_(atop)) and hollow-type(^(*)CO_(hollow)) adsorption of ^(*)CO species occurred on the CO-Cu_(2)O.The asymmetric C-C coupling energy barrier between ^(*)CO_(atop) and ^(*)CO_(hollow) in(311) crystal plane decreases by 47.8 % compared to the symmetric coupling of ^(*)CO_(atop) in conventional(100) crystal planes.Consequently,the Faradaic efficiency of C_(2) products generated with CO-Cu_(2)O was increased by as high as 100 % compared to that with pristine Cu_(2)O.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
基金the financial support from the National Natural Science Foundation of China (Nos.U23A20677,22022610 and 52400137)"Pioneer" and "Leading Goose" R&D Program of Zhejiang (Nos.2022C03146 and 2023C03017)+2 种基金China Postdoctoral Science Foundation (No.2024T170805)Zhejiang Provincial Natural Science Foundation of China (No.LDT23E06015B06)the support of the Research Computing Center in College of Chemical and Biological Engineering at Zhejiang University for assistance with the calculations。
文摘Cuprous oxide(Cu_(2)O) is one of the most promising catalysts for electrochemical conversion of CO_(2) into value-added C_(2) products.The efficiency of CO_(2)-to-C_(2) conversion is highly dependent on the Cu_(2)O crystal plane orientation and the corresponding adsorbed ^(*)CO species.Herein,we constructed high-index crystal planes(311) in Cu_(2)O(CO-Cu_(2)O) via a facile self-selective CO-induced strategy under a CO atmosphere,which was verified by high-resolution transmission electron microscopy(HR-TEM) and atomic force microscopy(AFM) results.By exploiting the high surface energy of the high index crystal planes,^(*)CO species are stabilized in CO-Cu_(2)O during CO_(2)RR,resulting in exceptional catalytic performance for CO_(2)-to-C_(2)products.In situ infrared spectroscopy revealed that both atop-type(^(*)CO_(atop)) and hollow-type(^(*)CO_(hollow)) adsorption of ^(*)CO species occurred on the CO-Cu_(2)O.The asymmetric C-C coupling energy barrier between ^(*)CO_(atop) and ^(*)CO_(hollow) in(311) crystal plane decreases by 47.8 % compared to the symmetric coupling of ^(*)CO_(atop) in conventional(100) crystal planes.Consequently,the Faradaic efficiency of C_(2) products generated with CO-Cu_(2)O was increased by as high as 100 % compared to that with pristine Cu_(2)O.
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.
