The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness...The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined. Based on all these data a semi-empirical model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions at 25℃ was proposed. The fitting result of this model is comparatively satisfactory. Compared to a former model, Gordon Model, this model can avoid a number of difficulties and arduous work.展开更多
We demonstrate a very convenient access to self-suspended pure poly（10,12-pentacosadiynoic acid） （PDA） nanoparticles （NPs） simply by adding the ethanol solution of diacetylene monomer to water, followed by UV ir...We demonstrate a very convenient access to self-suspended pure poly（10,12-pentacosadiynoic acid） （PDA） nanoparticles （NPs） simply by adding the ethanol solution of diacetylene monomer to water, followed by UV irradiation. The as-obtained PDA NPs are of high purity because no any initiator, catalyst or stabilizer was used during the whole process. The stabilizer-free PDA NPs are stable in the aqueous suspension. Due to the high purity and stability, the PDA NPs can respond sensitively and selectively to lysine and arginine among 18 kinds of water soluble natural amino acids; without the competitive interaction from the stabilizer, the sensitivity was enhanced.展开更多
The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal di...The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal diet (37.99% crude protein and 7.28% crude lipid) to provide graded levels of Lys and Arg. The experimental diets contained three Lys levels (2.51%, 2.11%, and 1.70% of total diet), and three Arg levels (1.41%, 1.80%, and 2.21% of total diet) and all combinations of these levels were tested. Pacific white shrimp, with a mean weight of 3.62±0.1 g, were randomly distributed in 36 fiberglass tanks with 30 shrimp per tank and reared on the experimental diets for 50 days. After the feeding trial, the growth performance, survival, feed conversion rate (FCR), body composition and protease and lipase activities in the hepatopancreases of the experimental shrimps were determined. The results show that weight gain (WG), specific growth rate (SGR), FCR, body protein, body Lys and Arg content were significantly affected by dietary Lys and Arg (P<0.05) and improved when dietary Lys and Arg levels were 2.11% 2.51% and 1.80% 2.21%, respectively. Protease and lipase activities in the hepatopancreases of the shrimps appeared higher when dietary Lys and Arg quantities were 2.11% 2.51% and 1.80% 2.21%, although the difference was not statistically significant (P>0.05). Therefore, according to our results, the optimal Lys and Arg quantities in the diet of Pacific white shrimp, L. vannamei, were considered to be 2.11%-2.51% and 1.80%- 2.21%, respectively, and the optimal ratio to be 1:0.88-1:1.05.展开更多
Prof.Li Haitao’s laboratory at the School of Medicine,Tsinghua University,reported the molecular basis underlying histone H3 lysine-arginine methylation pattern readout by Spin/Ssty repeats of Spindlinl,which was pub...Prof.Li Haitao’s laboratory at the School of Medicine,Tsinghua University,reported the molecular basis underlying histone H3 lysine-arginine methylation pattern readout by Spin/Ssty repeats of Spindlinl,which was published in Genes&.Development(2014.28:622—636).Histone methylation patterns and their combinatorial readout have emerged as a fundamental mechanism for epigenetic regulation.Spindlinl is a member of the Spin/Ssty family of proteins,which consists of展开更多
文摘The diffusion coefficients of l-lysine hydrochloride and I-arginine hydrochloride in their aqueous solutions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined. Based on all these data a semi-empirical model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions at 25℃ was proposed. The fitting result of this model is comparatively satisfactory. Compared to a former model, Gordon Model, this model can avoid a number of difficulties and arduous work.
文摘We demonstrate a very convenient access to self-suspended pure poly（10,12-pentacosadiynoic acid） （PDA） nanoparticles （NPs） simply by adding the ethanol solution of diacetylene monomer to water, followed by UV irradiation. The as-obtained PDA NPs are of high purity because no any initiator, catalyst or stabilizer was used during the whole process. The stabilizer-free PDA NPs are stable in the aqueous suspension. Due to the high purity and stability, the PDA NPs can respond sensitively and selectively to lysine and arginine among 18 kinds of water soluble natural amino acids; without the competitive interaction from the stabilizer, the sensitivity was enhanced.
基金Supported by the Research Foundation for Advanced Talents, Qingdao Agricultural University (No.631109)
文摘The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal diet (37.99% crude protein and 7.28% crude lipid) to provide graded levels of Lys and Arg. The experimental diets contained three Lys levels (2.51%, 2.11%, and 1.70% of total diet), and three Arg levels (1.41%, 1.80%, and 2.21% of total diet) and all combinations of these levels were tested. Pacific white shrimp, with a mean weight of 3.62±0.1 g, were randomly distributed in 36 fiberglass tanks with 30 shrimp per tank and reared on the experimental diets for 50 days. After the feeding trial, the growth performance, survival, feed conversion rate (FCR), body composition and protease and lipase activities in the hepatopancreases of the experimental shrimps were determined. The results show that weight gain (WG), specific growth rate (SGR), FCR, body protein, body Lys and Arg content were significantly affected by dietary Lys and Arg (P<0.05) and improved when dietary Lys and Arg levels were 2.11% 2.51% and 1.80% 2.21%, respectively. Protease and lipase activities in the hepatopancreases of the shrimps appeared higher when dietary Lys and Arg quantities were 2.11% 2.51% and 1.80% 2.21%, although the difference was not statistically significant (P>0.05). Therefore, according to our results, the optimal Lys and Arg quantities in the diet of Pacific white shrimp, L. vannamei, were considered to be 2.11%-2.51% and 1.80%- 2.21%, respectively, and the optimal ratio to be 1:0.88-1:1.05.
基金support by the National Natural Science Foundation of China(Grant Nos.31221064 and 81272235)
文摘Prof.Li Haitao’s laboratory at the School of Medicine,Tsinghua University,reported the molecular basis underlying histone H3 lysine-arginine methylation pattern readout by Spin/Ssty repeats of Spindlinl,which was published in Genes&.Development(2014.28:622—636).Histone methylation patterns and their combinatorial readout have emerged as a fundamental mechanism for epigenetic regulation.Spindlinl is a member of the Spin/Ssty family of proteins,which consists of
