Twelve peptides, including eight conservative amino acid residuesin the amino acid sequence of hydrophilic S helix of the alternative oxidase (AOX), were synthesized by solid-phase method. The polypeptide was coupled ...Twelve peptides, including eight conservative amino acid residuesin the amino acid sequence of hydrophilic S helix of the alternative oxidase (AOX), were synthesized by solid-phase method. The polypeptide was coupled with a-chymotrypsinogen, and the antibodies were obtained through immunizing domestic rabbit by injecting this complex. By using these antibodies, which were raised to immunoreact with total proteins of purified mitochondria from different organs of mung bean seedlings, we find that there are two hybridizable AOX bands in mitochondria. Their molecular weights are about 35 and 38 ku, respectively. Moreover, the respiratory parameters of hypocotyl, true leaf and cotyledon of mung bean seedlings show that true leaf has the highest total respiration (Vt), alternative pathway (AP) capacity (Valt) and the activity of AP (ρValt) among the three organs. Vt and ρValt of cotyledon ranked the second. Hypocotyl has the lowest Vt and ρValt, but its Valt is higher than that of cotyledon. These results are consistent with the analysis of Western blotting of expression of AOX. The highest Vt and ρValt in true leaf are accompanied two hybridizable polypeptides of AOX protein, 35 ku and 38 ku respectively. The next is cotyledon Vt and ρValt with only one 38 ku hybridizable polypeptide of AOX protein. Hypocotyl Vt and ρValt is the lowest and its immunoblotting band is similar to that of cotyledon, but the expressive amount of 38 ku protein is less than that of cotyledon. The results suggest that the 35 ku AOX may contribute mainly to true leaf ρValt.展开更多
Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The pr...Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The present study investigated the tolerant capacity of 8 individuals during incremental work load. The 8 subjects were required to wear two matched respirators （respirators Ⅰ and Ⅱ which were designed to have different breathing resistances and the same dead space） respectively on separate days and then work to end points. Minute ventilation （VE）, breathing frequency （BF）, oxygen consumption （VO2） and heart rate （HR） were recorded during exercise, while tolerant time, response time and breathing discomfort were measured at the end of each test trial. The test variables were com-pared between the two respirators by using matched-pairs t-test. The results showed that the tolerant time was significantly reduced for the respiratorⅠwith higher level of breathing resistance when compared with its counterpart with lower breathing resistance （respirator Ⅱ） （P〈0.05）. The same changes occurred for response time. Results also showed a significant increase in VE and BF for respirator Ⅰwearers when the work load was above 125 W. The O2 consumption was similar under the two breathing resistance conditions. These findings suggested that the respiratory resistance caused by self-contained breathing apparatus （SCBA） has an impact on the tolerant capacity of users.展开更多
Osmotic dehydration of wheat seedlings in-0.5 MPa polyethylene glycol （PEG） solutions for 24, 48 and 72 h resulted in mild, moderate and severe water stress respectively in leaves, but only caused mild water stress ...Osmotic dehydration of wheat seedlings in-0.5 MPa polyethylene glycol （PEG） solutions for 24, 48 and 72 h resulted in mild, moderate and severe water stress respectively in leaves, but only caused mild water stress in roots as reflected by the changes in relative water content （RWC）. In response to the above water stress conditions, leaf total respiratory rate （V<sub>t</sub>） decreased progressively, and the alternative pathway （AP） capacity (V<sub>alt</sub>) and its actual operation activity (ρV<sub>alt</sub>) decreased more severely. Water stress also led to continuous reduction in cytochrome pathway （CP） activity ((ρ’ V<sub>cyt</sub>) and different changes in the contribution of ρV<sub>alt</sub> and ρ’ V<sub>cyt</sub> to V<sub>t</sub> in leaves, with ρV<sub>alt</sub>/V<sub>t</sub> decreasing and ρ’ V<sub>cyt</sub>/V<sub>t</sub> increasing. The change pattern of root V<sub>t</sub> was similar to that of its RWC, while root V<sub>alt</sub> and ρV<sub>alt</sub> were found to decrease during the first 24 h of stress and thereafter recover to a level close to that of the control （O h）. These data indicate that the展开更多
[目的]烧结钕铁硼(Nd Fe B)的电镀前处理技术还不够成熟,开发适宜的前处理工艺极其重要。[方法]在电镀铜前,先采用以羟基乙叉二膦酸(HEDP)为主配位剂的溶液对NdFeB进行预浸。预浸液组成和工艺条件为:HEDP 20~30 g/L,氢氧化钾20~25 g/L,...[目的]烧结钕铁硼(Nd Fe B)的电镀前处理技术还不够成熟,开发适宜的前处理工艺极其重要。[方法]在电镀铜前,先采用以羟基乙叉二膦酸(HEDP)为主配位剂的溶液对NdFeB进行预浸。预浸液组成和工艺条件为:HEDP 20~30 g/L,氢氧化钾20~25 g/L,碳酸钾10~15 g/L,葡萄糖酸钾1~2 g/L,乙酸0.5~1.0 g/L,室温,时间60 s。通过电化学测试对比了Nd Fe B基体有无预浸处理时,铜在其表面的电沉积行为,并通过金相显微镜、扫描电镜、能谱仪和荧光光谱测厚仪,对比了有无预浸处理的Nd FeB基体表面Cu镀层的宏观和微观表面形貌、截面形貌、元素分布及厚度分布均匀性。[结果]Nd Fe B基体预浸后表面被活化,静态电位降低。预浸液能够填满基体表面的孔隙并形成一层水薄膜,在后续电镀铜时保护基体不被腐蚀。预浸处理的Nd Fe B基体表面所得Cu镀层均匀、致密,不易氧化发黑,结合力和耐蚀性较好。[结论]对烧结钕铁硼进行预浸处理,能够保证其在后续电镀铜过程不被腐蚀,提高Cu镀层的综合性能。展开更多
High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners.This paper aims at quantitatively evaluating the respirators used in deep coal min...High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners.This paper aims at quantitatively evaluating the respirators used in deep coal mines and providing scientific guidance for the respiratory protection of miners.Based on the self-designed in-situ PM2.5 collector,controllable PM2.5 generator,human breathing simulator,and respirator simulation testing system,under the simulated deep mine working condition,this study investigated the effects of dust loading,wearing time,and dust concentration on the filtration efficiency,breathing resistance,and quality factor of N95 elastomeric respirators.With the increase of dust loading,the respirator filtration efficiency firstly decreased,then increased(minimum value 97.5%).The breathing resistance increased exponentially from 120 to 180 to 1020-1530 Pa,and the quality factor decreased logarithmically from 0.051 to 0.076 to 0.0058-0.0085 Pa^(-1).As the PM2.5 coal dust concentration increased from 5 to 50 mg/m^(3),the wearing time for the respirator breathing resistance to exceed 300 Pa reduced from 7 h to less than 1 h.One N95 elastomeric respirator is not able to perform an 8-h work shift.To avoid the excessive breathing resistance caused by dust loading,more filter cartridges are needed for coal miners.展开更多
One mM KCN fully inhibited the activity of cytochrome oxidase and the succinateoxidation in corn mitochondris, while the oxygen uptake of α-ketoglutarate was not affectedat all. In the latter case, a very strong inhi...One mM KCN fully inhibited the activity of cytochrome oxidase and the succinateoxidation in corn mitochondris, while the oxygen uptake of α-ketoglutarate was not affectedat all. In the latter case, a very strong inhibition could occur when both KCN and KSCNwere simultaneously present. After cyanide inhibition of succinate oxidation, the oxygen uptake could subsequentlyreappear by addition of α-ketoglutarate, but at that time the cytochromes c and a stillremained in their reduced state. In contrast to the cyanide-resistance,α-ketoglutarate oxidation was inhibited by antimycin A. It has been suggested that cytochromes a and c are not involved in the cyanide-insensi-tive alternative pathway in corn mitochondria and the branching point is located on the mainrespiratory chain after cytochrome b instead of before it.展开更多
基金the National Natural Science Foundation of China (Grant No. 39670070).
文摘Twelve peptides, including eight conservative amino acid residuesin the amino acid sequence of hydrophilic S helix of the alternative oxidase (AOX), were synthesized by solid-phase method. The polypeptide was coupled with a-chymotrypsinogen, and the antibodies were obtained through immunizing domestic rabbit by injecting this complex. By using these antibodies, which were raised to immunoreact with total proteins of purified mitochondria from different organs of mung bean seedlings, we find that there are two hybridizable AOX bands in mitochondria. Their molecular weights are about 35 and 38 ku, respectively. Moreover, the respiratory parameters of hypocotyl, true leaf and cotyledon of mung bean seedlings show that true leaf has the highest total respiration (Vt), alternative pathway (AP) capacity (Valt) and the activity of AP (ρValt) among the three organs. Vt and ρValt of cotyledon ranked the second. Hypocotyl has the lowest Vt and ρValt, but its Valt is higher than that of cotyledon. These results are consistent with the analysis of Western blotting of expression of AOX. The highest Vt and ρValt in true leaf are accompanied two hybridizable polypeptides of AOX protein, 35 ku and 38 ku respectively. The next is cotyledon Vt and ρValt with only one 38 ku hybridizable polypeptide of AOX protein. Hypocotyl Vt and ρValt is the lowest and its immunoblotting band is similar to that of cotyledon, but the expressive amount of 38 ku protein is less than that of cotyledon. The results suggest that the 35 ku AOX may contribute mainly to true leaf ρValt.
文摘Respirator breathing resistance impacts performance of wearers during constant work load. However, it is less clear as to how breathing resistance affects the tolerant capacity of users during graded work load. The present study investigated the tolerant capacity of 8 individuals during incremental work load. The 8 subjects were required to wear two matched respirators （respirators Ⅰ and Ⅱ which were designed to have different breathing resistances and the same dead space） respectively on separate days and then work to end points. Minute ventilation （VE）, breathing frequency （BF）, oxygen consumption （VO2） and heart rate （HR） were recorded during exercise, while tolerant time, response time and breathing discomfort were measured at the end of each test trial. The test variables were com-pared between the two respirators by using matched-pairs t-test. The results showed that the tolerant time was significantly reduced for the respiratorⅠwith higher level of breathing resistance when compared with its counterpart with lower breathing resistance （respirator Ⅱ） （P〈0.05）. The same changes occurred for response time. Results also showed a significant increase in VE and BF for respirator Ⅰwearers when the work load was above 125 W. The O2 consumption was similar under the two breathing resistance conditions. These findings suggested that the respiratory resistance caused by self-contained breathing apparatus （SCBA） has an impact on the tolerant capacity of users.
基金Project supported by the National Natural Science Foundation of China (Grant No.39670070).
文摘Osmotic dehydration of wheat seedlings in-0.5 MPa polyethylene glycol （PEG） solutions for 24, 48 and 72 h resulted in mild, moderate and severe water stress respectively in leaves, but only caused mild water stress in roots as reflected by the changes in relative water content （RWC）. In response to the above water stress conditions, leaf total respiratory rate （V<sub>t</sub>） decreased progressively, and the alternative pathway （AP） capacity (V<sub>alt</sub>) and its actual operation activity (ρV<sub>alt</sub>) decreased more severely. Water stress also led to continuous reduction in cytochrome pathway （CP） activity ((ρ’ V<sub>cyt</sub>) and different changes in the contribution of ρV<sub>alt</sub> and ρ’ V<sub>cyt</sub> to V<sub>t</sub> in leaves, with ρV<sub>alt</sub>/V<sub>t</sub> decreasing and ρ’ V<sub>cyt</sub>/V<sub>t</sub> increasing. The change pattern of root V<sub>t</sub> was similar to that of its RWC, while root V<sub>alt</sub> and ρV<sub>alt</sub> were found to decrease during the first 24 h of stress and thereafter recover to a level close to that of the control （O h）. These data indicate that the
文摘[目的]烧结钕铁硼(Nd Fe B)的电镀前处理技术还不够成熟,开发适宜的前处理工艺极其重要。[方法]在电镀铜前,先采用以羟基乙叉二膦酸(HEDP)为主配位剂的溶液对NdFeB进行预浸。预浸液组成和工艺条件为:HEDP 20~30 g/L,氢氧化钾20~25 g/L,碳酸钾10~15 g/L,葡萄糖酸钾1~2 g/L,乙酸0.5~1.0 g/L,室温,时间60 s。通过电化学测试对比了Nd Fe B基体有无预浸处理时,铜在其表面的电沉积行为,并通过金相显微镜、扫描电镜、能谱仪和荧光光谱测厚仪,对比了有无预浸处理的Nd FeB基体表面Cu镀层的宏观和微观表面形貌、截面形貌、元素分布及厚度分布均匀性。[结果]Nd Fe B基体预浸后表面被活化,静态电位降低。预浸液能够填满基体表面的孔隙并形成一层水薄膜,在后续电镀铜时保护基体不被腐蚀。预浸处理的Nd Fe B基体表面所得Cu镀层均匀、致密,不易氧化发黑,结合力和耐蚀性较好。[结论]对烧结钕铁硼进行预浸处理,能够保证其在后续电镀铜过程不被腐蚀,提高Cu镀层的综合性能。
基金supported by the National Natural Science Foundation of China(No.51904291)the Basic Research Program of Jiangsu Province(No.BK20190638)+2 种基金the Fundamental Research Funds for the Central Universities(No.2020XGYJ08)the Project funded by China Postdoctoral Science Foundation(No.2020 M681781),the Jiangsu Planned Projects for Postdoctoral Research Funds(No.2020Z076)the State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by Shandong Province and the Ministry of Science and Technology(No.SICGM202105).
文摘High humidity and high dust concentration in deep coal mines may severely challenge the performance of respirators worn by coal miners.This paper aims at quantitatively evaluating the respirators used in deep coal mines and providing scientific guidance for the respiratory protection of miners.Based on the self-designed in-situ PM2.5 collector,controllable PM2.5 generator,human breathing simulator,and respirator simulation testing system,under the simulated deep mine working condition,this study investigated the effects of dust loading,wearing time,and dust concentration on the filtration efficiency,breathing resistance,and quality factor of N95 elastomeric respirators.With the increase of dust loading,the respirator filtration efficiency firstly decreased,then increased(minimum value 97.5%).The breathing resistance increased exponentially from 120 to 180 to 1020-1530 Pa,and the quality factor decreased logarithmically from 0.051 to 0.076 to 0.0058-0.0085 Pa^(-1).As the PM2.5 coal dust concentration increased from 5 to 50 mg/m^(3),the wearing time for the respirator breathing resistance to exceed 300 Pa reduced from 7 h to less than 1 h.One N95 elastomeric respirator is not able to perform an 8-h work shift.To avoid the excessive breathing resistance caused by dust loading,more filter cartridges are needed for coal miners.
文摘One mM KCN fully inhibited the activity of cytochrome oxidase and the succinateoxidation in corn mitochondris, while the oxygen uptake of α-ketoglutarate was not affectedat all. In the latter case, a very strong inhibition could occur when both KCN and KSCNwere simultaneously present. After cyanide inhibition of succinate oxidation, the oxygen uptake could subsequentlyreappear by addition of α-ketoglutarate, but at that time the cytochromes c and a stillremained in their reduced state. In contrast to the cyanide-resistance,α-ketoglutarate oxidation was inhibited by antimycin A. It has been suggested that cytochromes a and c are not involved in the cyanide-insensi-tive alternative pathway in corn mitochondria and the branching point is located on the mainrespiratory chain after cytochrome b instead of before it.
