Shao Chunlin

Dose-effect of the tyrosine sample implanted by a low energy N+ ion beam

Abstract It has been found that the sample of tyrosine implanted by a low energy N + ion beam had a special dose-effect that was different from traditional theory. A mathematical equation of this special regulation was deduced; it reflected the importance of depositing of the slowed-down ions. In this paper, the interaction between the implantation N + with the tyrosine molecules was also analyzed.

Mass deposition in tyrosine irradiated by a N+ ion

Abstract Based on the measured UV-, IR-, laser-Raman, and mass spectra, and analyzed with the quantum theory, the reaction pattern of an implanted N + ion with tyrosine molecule (Tyr) was deduced. It was found that a substitute reaction of the slow down N + with the group C(5)H- of Tyrs benzene ring had taken place. In addition, a new carbonyl group was measured in the irradiated Tyr sample. Hence, a N-heterocyclic compound was formed.

Research into releasing inorganic phosphate and base from 5′-dTMP irradiated by a low energy ion beam

Abstract Research into radiation damage of nucleotide is an important area in radiation biology. In this paper, the yield of inorganic phosphate and base released from 5′-dTMP irradiated by a 30 keV N + ion beam was investigated in several aspects. The effect of particle fluence on yield and the influence of treatment with 0.1 N NaOH was deduced. By analysis, it is known that the alkali treatment not only increases the yield of inorganic phosphate, but also damages and splits the base released from irradiated 5′-dTMP. When the irradiated samples are treated by 0.1 N NaOH immediately, the yield of inorganic phosphate is increased by a factor of 1.7 and the concentration of base decreased to half of the original value. But the yield of inorganic phosphate could be increased by a factor of 2.8 after 40 min of alkali treatment. On the other hand, when 5prime;-dTMP was irradiated by the ion beam, the G(Pi) obtained was above 0.44, higher than with γ-radiation.

Synthesis of amino acids by arc-discharge experiments

Abstract Discharge was performed against ammonia water using a graphite rod as the anode and a silver thread as the cathode under an Ar atmosphere. HPLC and thin layer chromatograph (TLC) analyses showed that three kinds of amino acids were produced in the reaction mixture. As the graphite anode is the solitary source of carbon in the system, it is considered that amino acids have been produced by synthetic reaction between graphite and ammonia water. Thus, our results provide a possible way of formation of amino acids from elemental carbon on the primitive earth. In addition, the mechanism for the production of amino acids is discussed and the yields of different amino acids are presented.

Phosphate release from N+ ions irradiated 5'-CMP nucleotide and its kinetics

Abstract Ion beam irradiation-induced inorganic phosphate (Pi) release from 5′-CMP nucleotide could be divided into two parts: fast process and slow process. The yield of Pi released from the fast process not only had a non-linear response to irradiation dose, but was also influenced by post-irradiation treatments. It was found that heat treatment and alkali treatment increased the yield of Pi but acid treatment decreased it. With the heat treatment lower than 80°C, the Pi release process followed the first order reaction model, but under the conditions of 95°C treatment and alkali treatment the Pi release process followed the second order reaction model. Moreover, the kinetics equations and the rate constants of different models of the Pi release reactions were deduced.