11 resultados para 88-581C
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
以UNCG, GNRA , CUU G (N = A , U , C 或G; R = G或A) 为端环能够形成稳定的、保 守的发夹结构. 它们具有特殊的结构特征, 并在体内发挥着重要的生物学功能. 这些稳定的发夹 广泛分布于体内rRNA , 催化RNA 和非编码mRNA 中. 但对人类88 个编码区mRNA 二级结构的 研究当中, 却没有发现C(UUCG) G发夹. 而且, 与rRNA 不同, 这些编码区mRNA 四环序列的 分布没有明显的偏好性.
Resumo:
RNA hairpins containing UNCG, GNRA, CUUG (N = A, U, C or G, R = G or A) loops are unusually thermodynamic stable and conserved structures. The structural features of these hairpin loops are very special, and they play very important roles in vivo. They are prevalent in rRNA, catalytic RNA and non-coding mRNA. However, the 5' C(UUCG)G 3' hairpin is not found in the folding structure of 88 human mRNA coding regions. It is also different from rRNA in that there is no preference for certain sequences among tetraloops in these 88 mRNA folding structures.
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设计并制作了一种重排无阻塞型的8×8 SOI热光波导开关阵列。开关单元采用了MM I-MZI结构的2×2光开关。整个器件的开关时间约为2μs。器件中开关单元功耗小于240mW。消光比在17~22dB范围内变化。功耗和开关速度都明显优于SiO2基和聚合物基的开关阵列。
Resumo:
制作了光互连用8×8多量子阱空间光调制器,测量了其耐压特性、模式均匀性、对比度和插入损耗等。使用Dammann光栅分束器将半导体激光束分成等光强的64路并将其照射到多量子阱空间光调制器上,测量了其调制特性。
Resumo:
国家自然科学基金
Resumo:
在用82Se束流和天然 Ba靶之间的深部非弹反应研究类靶余核激发态时,Ba靶严重氧化,88Sr的激发态由16O与82Se之间的融合蒸发反应产生.通过在束γ谱学方法测量了88 Sr的退激 γ射线,提取了γ跃迁的 DCO系数和角分布各向异性因子,对所有能级进行了自旋指定.在已知能级之上观测到了两个高自旋能级结构,自旋、激发能分别达到13h,8520keV和12h,7909keV.根据能级衰变特征和邻近N=50同中子素的能级结构系统性,对高自旋态的组态进行了讨论.
Resumo:
描述了1个8×8单元CsI(Tl)探测阵列的结构和工作原理。探测阵列的每个单元是由1块前表面21 mm×21 mm、后表面23.1 mm×23.1 mm、高50 mm的CsI(Tl)棱台、1块光导和光电倍增管组成。在兰州放射性次级束流线(RIBLL)上对探测阵列进行测试,得到探测阵列对30 MeV质子的能量分辨可达2.7%,对170 MeV7Be可达1.5%,可很好地用于放射性束物理实验中带电粒子的鉴别。
Resumo:
近二十年,世界上各大实验室相继建立了各具特色的放射性束流装置,放射性束物理得到了长足的发展,在实验上要求对反应产物进行全运动学测量且具有较高的精度,为实验探测装置提出了更高的要求。我们研制了8×8单元CsI(Tl)阵列探测器,主要用于测量核反应产物的能量和角分布、进行粒子的关联测量以及对粒子的鉴别。脉冲形状甄别(PSD)技术是一种重要的鉴别粒子的方法,已经从原来直接利用电子学硬件的方法发展到先采集到脉冲波形,进而进行离线分析,甚至利用现代数字信号处理(DSP)技术的在线分析。我们对该技术进行了一些初步的研究,为以后利用DSP技术研制PSD系统奠定了重要的基础。本论文工作的主要内容有:(1)探测器的研制和性能测试。该探测器由64块CsI(Tl)晶体组成,每块晶体由光电倍增管单独读出。该探测器覆盖较大的立体角,具有较好的能量分辨和粒子鉴别能力。本文对探测器的探测原理,结构及性能进行较详细的说明。(2)系统地对两部分比较法(Qfast/Qslow,Qfast/Qtotal,Qslow/Qtotal)进行了模拟计算,定性的分析了两部分的积分门的延迟和宽度,为实验提供了有效的指导。分别采集到α源和宇宙线(m子)两种脉冲波形,使用两部分比较、平均时间、确定幅度和确定时间四种方法进行离线分析,对四种分析方法进行比较,以选择甄别效果最好的分析方法。最后,对关于进一步工作的方向进行了简要的讨论
Resumo:
Myeloid differentiation factor 88 (MyD88) is a universal and essential adapter for the TLR/IL-1R family. In this report, the first mollusk Myd88 ortholog (named as CfMyd88) was cloned from Zhikong scallop (Chlamys farreri). The full-length cDNA of CfMyd88 was of 1554 bp, including a 5 '-terminal untranslated region (UTR) of 427 bp, a polyA tail, and an open reading frame (ORF) of 1104 bp encoding a polypeptide of 367 amino acids containing the typical TLR and IL-1R-related (TIR) domain and death domain (DD). Homology analysis revealed that the predicted amino acid sequence of CfMyd88 was homologous to a variety of previously identified Myd88s with more than 30% identity. The temporal expressions of CfMyd88 mRNA in the mixed primary cultured haemocytes stimulated by lipopolysaccharide (LPS) and peptidoglycans (PGN) were measured by real-time RT-PCR system. The mRNA expression of CfMyd88 decreased after stimulation with both LPS and PGN, and the lowest level was about 1/3 times (at 6 h) and 1/10 times (at 9 h) to that in the control group, respectively. The expression then recovered and was upregulated to two-fold at 9 h after LPS stimulation or to the original level at 12 It after PGN stimulation. The results suggest that the MyD88-dependent signaling pathway exists in scallop and was involved in the defense system. (c) 2007 Elsevier Ltd. All rights reserved.