In this paper, we consider the problem of the uniqueness for meromorphic functions whose n-th derivatives share the same 1-points. The results in this paper are different from all of theorems given by H X Yi and C C Y...In this paper, we consider the problem of the uniqueness for meromorphic functions whose n-th derivatives share the same 1-points. The results in this paper are different from all of theorems given by H X Yi and C C Yang and other authors.展开更多
N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a...N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and the ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.展开更多
基金Foundation item: Supported by the NSF of China(10471028)Supported by the NSF of Guangdong Province(020586) Supported by the Guangzhou Education Bureau(2006, 2025)Supported by the Grant-in-Aid for Scientific Research 2004(15540151)Supported by the Japan Society for the Promotion of Science
文摘In this paper, we consider the problem of the uniqueness for meromorphic functions whose n-th derivatives share the same 1-points. The results in this paper are different from all of theorems given by H X Yi and C C Yang and other authors.
文摘N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and the ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.
