## 2009年  第26卷  第2期

2009, 26(2): 85-92. doi: 10.11804/NuclPhysRev.26.02.085

2009, 26(2): 93-101. doi: 10.11804/NuclPhysRev.26.02.093

2009, 26(2): 102-106. doi: 10.11804/NuclPhysRev.26.02.102

2009, 26(2): 107-111. doi: 10.11804/NuclPhysRev.26.02.107

2009, 26(2): 112-116. doi: 10.11804/NuclPhysRev.26.02.112

2009, 26(2): 117-122. doi: 10.11804/NuclPhysRev.26.02.117

2009, 26(2): 123-126. doi: 10.11804/NuclPhysRev.26.02.123

2009, 26(2): 127-135. doi: 10.11804/NuclPhysRev.26.02.127

2009, 26(2): 136-139. doi: 10.11804/NuclPhysRev.26.02.136

The light output of the BC501A liquid scintillation detector for
γrays was calibrated by serial monoenergetic γray sources. The Monte Carlo simulation method to confirm Compton edge was described briefly. The result was compared with that obtained by the semiheight method. The γray response matrix of BC501A liquid scintillation detector was calculated by the Monte Carlo code PHRESP from PTB. The method of using response function matrix and recoil electron spectrum to unfold γray energy spectrum was introduced and the error of unfolding spectrum was also briefly discussed.

2009, 26(2): 140-145. doi: 10.11804/NuclPhysRev.26.02.140

2009, 26(2): 146-149. doi: 10.11804/NuclPhysRev.26.02.146

2009, 26(2): 150-153. doi: 10.11804/NuclPhysRev.26.02.150

2009, 26(2): 154-157. doi: 10.11804/NuclPhysRev.26.02.154

2009, 26(2): 158-162. doi: 10.11804/NuclPhysRev.26.02.158

2009, 26(2): 163-167. doi: 10.11804/NuclPhysRev.26.02.163

Depending on their unique physical properties， proton and heavy ions have taken an irreplaceable role in modern means of tumor treatment. Onestep process and twostep process physical models were employed to explain the mechanism of ion energy loss. The transport process of proton and 12C in water was simulated by Geant4 toolkit to study the physical properties of ion beam. The calculation results were discussed， which showed the advantages and disadvantages of proton and 12C in the medical application.

2009, 26(2): 168-171. doi: 10.11804/NuclPhysRev.26.02.168

To explore the effects of different linear energy transfer(LET）of 12C6+ ion Beam irradiation on BJ1, survivals and biocontrol effects were cultured and treated with LET＝40 and 60 keV/μm at the doses of 50, 100, 200, 400 and 600 Gy, respectively. The results showed more mutations and biocontrol charts and higher survivals were obtained with high LET(60 keV/μm） irradiations at lower dose, which was useful to screen good positive mutations. Based on the results above, it could be concluded that the condition of high LET(60 keV/μm） had obvious mutagenic effects than that of low LET(40 keV/μm）.
2009, 26(2): 172-176. doi: 10.11804/NuclPhysRev.26.02.172

MicroRNA(miRNA)是一类大小为19—24个核苷酸的非编码RNA， 它们通过与靶基因的信使RNA(mRNA)结合在转录后水平调节靶基因的表达， 因而在广泛的生物学过程中发挥重要作用。 首先从miRNA的获得和鉴定两方面对目前miRNA发现工作进行了概括， 然后分析和总结了近年来人源miRNA发现工作的现状， 最后提出有关新miRNA发现工作的新想法。 MicroRNAs(miRNAs) are one kind of small noncoding RNAs of 19—24 nucleotides that transcriptionally regulate the expression of target genes by binding to their mRNA and thus play a central role in gene regulation in a wide arrange of biological processes. In this paper， we reviewed the clone and identification of novel miRNAs， summarized recent work on novel human miRNA recognization， and proposed a potentially feasible way to discover more human miRNAs.