Three goats were fed with ^15N-labelled rice straw to study the characteristics of digestion,assimilation,transformation and excretion of C and N compounds from rice straw.It was shown that the amount of ^15N transfor...Three goats were fed with ^15N-labelled rice straw to study the characteristics of digestion,assimilation,transformation and excretion of C and N compounds from rice straw.It was shown that the amount of ^15N transformed into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of ^15N deposition of the experimental diet taken by each goat.The ^15N excreted through the feces and urine for the three goats accounted for 34.8,33.2 and 33.9% of the total amount of ^15N deposition in the feed of the 3 goats.The recovery of total ^15N for the two slaughtered goats were 73.3 and 57.5%,with the corresponding rates of ^15N loss 26.7 and 42.5% respectively.The digestibilities of total amino acids for Goats 1 and 3 were 68.7 and 54.0%,and the digestibilties of carbohydrates for the two goats were 74.8 and 67.7% respectively.展开更多
Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross ...Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and O-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4P207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaOH, and the HA extracted by 0.1 mol L-1 NaOH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.展开更多
Nitrogenous fertilisers are under consideration for promoting the growth of nursery-reared hoop pine （Araucaria cunninghamii Alton ex A. Cunn） seedlings in the establishment phase of second rotation （2R） plantatio...Nitrogenous fertilisers are under consideration for promoting the growth of nursery-reared hoop pine （Araucaria cunninghamii Alton ex A. Cunn） seedlings in the establishment phase of second rotation （2R） plantations. Using ^15N- labelled fertilisers, we investigated the effect of different forms （ammonium sulphate, ammonium nitrate, potassium nitrate and urea） and rates of application （0, 150 and 300 mg N kg^-1 dried soil） of fertilisers on the growth, ^15N recovery and carbon isotope composition （δ^13C） of hoop pine seedlings in a 12-month glasshouse trial in southeast Queensland, Australia. The ^15N-labelled fertilisers were applied to nursery-reared hoop pine seedlings, which were then grown in pots, containing ca. 1.2 kg dried soil, under well watered conditions for 12 months. Four seedlings from each treatment were harvested at 4-month intervals, divided into roots, stem and foliage, with a further subdivision for new and old foliage, and then analysed for ^15N, total N, δ^13C and total C. There was no significant response in the seedling growth to the form or rate of application of nitrogen （N） fertiliser within the 12-month period, indicating that the seedlings did not experience N deficiency when grown on second rotation hoop pine soils. While the combined ^15N recovery from soil and plant remained at around 70% throughout the experiment, the proportion of ^15N recovered from the plants increasing steadily over time. Nitrate containing fertilisers at 150 mg N kg^-1 soil gradually increased seedling foliage δ^13C over the 12-month period, indicating an increase in seedling water use efficiency.展开更多
目的探究Eps15同源结构域蛋白2(Eps15 homology domain-containing protein 2,EHD2)在结肠癌细胞中的作用及其分子机制。方法在SW620细胞系中构建过表达EHD2的细胞模型,检测EMT相关标志分子物的变化,研究过表达EHD2对细胞株的生物学行...目的探究Eps15同源结构域蛋白2(Eps15 homology domain-containing protein 2,EHD2)在结肠癌细胞中的作用及其分子机制。方法在SW620细胞系中构建过表达EHD2的细胞模型,检测EMT相关标志分子物的变化,研究过表达EHD2对细胞株的生物学行为包括转移、侵袭、增殖及凋亡的影响。最后运用异种移植肿瘤模型验证过表达EHD2对裸鼠体内结肠癌的发生及发展的影响。结果过表达EHD2会抑制结肠癌细胞的增殖、迁移、侵袭及促进凋亡;在裸鼠体内,过表达EHD2可以抑制裸鼠皮下肿瘤的生长;且EHD2与EMT相关标志物的表达呈正相关,推测EHD2通过抑制EMT途径抑制结肠癌的进展。结论EHD2可能作为抑癌基因通过EMT进程抑制结肠癌的侵袭和转移。展开更多
文摘Three goats were fed with ^15N-labelled rice straw to study the characteristics of digestion,assimilation,transformation and excretion of C and N compounds from rice straw.It was shown that the amount of ^15N transformed into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of ^15N deposition of the experimental diet taken by each goat.The ^15N excreted through the feces and urine for the three goats accounted for 34.8,33.2 and 33.9% of the total amount of ^15N deposition in the feed of the 3 goats.The recovery of total ^15N for the two slaughtered goats were 73.3 and 57.5%,with the corresponding rates of ^15N loss 26.7 and 42.5% respectively.The digestibilities of total amino acids for Goats 1 and 3 were 68.7 and 54.0%,and the digestibilties of carbohydrates for the two goats were 74.8 and 67.7% respectively.
基金Project (No. 39790100) supported by the National Natural Science Foundation of China.
文摘Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and O-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4P207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaOH, and the HA extracted by 0.1 mol L-1 NaOH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.
基金Project supported by a scholarship grant from the Cooperative Research Centre for Sustainable Production Forestry,Australia
文摘Nitrogenous fertilisers are under consideration for promoting the growth of nursery-reared hoop pine （Araucaria cunninghamii Alton ex A. Cunn） seedlings in the establishment phase of second rotation （2R） plantations. Using ^15N- labelled fertilisers, we investigated the effect of different forms （ammonium sulphate, ammonium nitrate, potassium nitrate and urea） and rates of application （0, 150 and 300 mg N kg^-1 dried soil） of fertilisers on the growth, ^15N recovery and carbon isotope composition （δ^13C） of hoop pine seedlings in a 12-month glasshouse trial in southeast Queensland, Australia. The ^15N-labelled fertilisers were applied to nursery-reared hoop pine seedlings, which were then grown in pots, containing ca. 1.2 kg dried soil, under well watered conditions for 12 months. Four seedlings from each treatment were harvested at 4-month intervals, divided into roots, stem and foliage, with a further subdivision for new and old foliage, and then analysed for ^15N, total N, δ^13C and total C. There was no significant response in the seedling growth to the form or rate of application of nitrogen （N） fertiliser within the 12-month period, indicating that the seedlings did not experience N deficiency when grown on second rotation hoop pine soils. While the combined ^15N recovery from soil and plant remained at around 70% throughout the experiment, the proportion of ^15N recovered from the plants increasing steadily over time. Nitrate containing fertilisers at 150 mg N kg^-1 soil gradually increased seedling foliage δ^13C over the 12-month period, indicating an increase in seedling water use efficiency.
文摘目的探究Eps15同源结构域蛋白2(Eps15 homology domain-containing protein 2,EHD2)在结肠癌细胞中的作用及其分子机制。方法在SW620细胞系中构建过表达EHD2的细胞模型,检测EMT相关标志分子物的变化,研究过表达EHD2对细胞株的生物学行为包括转移、侵袭、增殖及凋亡的影响。最后运用异种移植肿瘤模型验证过表达EHD2对裸鼠体内结肠癌的发生及发展的影响。结果过表达EHD2会抑制结肠癌细胞的增殖、迁移、侵袭及促进凋亡;在裸鼠体内,过表达EHD2可以抑制裸鼠皮下肿瘤的生长;且EHD2与EMT相关标志物的表达呈正相关,推测EHD2通过抑制EMT途径抑制结肠癌的进展。结论EHD2可能作为抑癌基因通过EMT进程抑制结肠癌的侵袭和转移。
