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排序方式: 共有126条查询结果,搜索用时 31 毫秒
121.
Watanabe H Fujiyama A Hattori M Taylor TD Toyoda A Kuroki Y Noguchi H BenKahla A Lehrach H Sudbrak R Kube M Taenzer S Galgoczy P Platzer M Scharfe M Nordsiek G Blöcker H Hellmann I Khaitovich P Pääbo S Reinhardt R Zheng HJ Zhang XL Zhu GF Wang BF Fu G Ren SX Zhao GP Chen Z Lee YS Cheong JE Choi SH Wu KM Liu TT Hsiao KJ Tsai SF Kim CG OOta S Kitano T Kohara Y Saitou N Park HS Wang SY Yaspo ML Sakaki Y 《Nature》2004,429(6990):382-388
Human-chimpanzee comparative genome research is essential for narrowing down genetic changes involved in the acquisition of unique human features, such as highly developed cognitive functions, bipedalism or the use of complex language. Here, we report the high-quality DNA sequence of 33.3 megabases of chimpanzee chromosome 22. By comparing the whole sequence with the human counterpart, chromosome 21, we found that 1.44% of the chromosome consists of single-base substitutions in addition to nearly 68,000 insertions or deletions. These differences are sufficient to generate changes in most of the proteins. Indeed, 83% of the 231 coding sequences, including functionally important genes, show differences at the amino acid sequence level. Furthermore, we demonstrate different expansion of particular subfamilies of retrotransposons between the lineages, suggesting different impacts of retrotranspositions on human and chimpanzee evolution. The genomic changes after speciation and their biological consequences seem more complex than originally hypothesized. 相似文献
122.
Quantum oscillations in two coupled charge qubits 总被引:9,自引:0,他引:9
A practical quantum computer, if built, would consist of a set of coupled two-level quantum systems (qubits). Among the variety of qubits implemented, solid-state qubits are of particular interest because of their potential suitability for integrated devices. A variety of qubits based on Josephson junctions have been implemented; these exploit the coherence of Cooper-pair tunnelling in the superconducting state. Despite apparent progress in the implementation of individual solid-state qubits, there have been no experimental reports of multiple qubit gates--a basic requirement for building a real quantum computer. Here we demonstrate a Josephson circuit consisting of two coupled charge qubits. Using a pulse technique, we coherently mix quantum states and observe quantum oscillations, the spectrum of which reflects interaction between the qubits. Our results demonstrate the feasibility of coupling multiple solid-state qubits, and indicate the existence of entangled two-qubit states. 相似文献
123.
P Nara W P Tsai H F Kung A Minassian R Garrity J Goudsmit G Rimmelzwaan 《Nature》1992,360(6401):215-216
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125.
研究了聚硅氧烷/聚砜二元嵌段共聚物(PMS/PSF)的成膜行为和膜强度,讨论PMS、吡啶侧基、Co(Salen)含量对它们的影响;测定了膜对空气的透过率和富氧率,总结出该膜的富氧率随PMS含量、温度、压力改变的变化规律,当软硬段含量相近时,PMS/PSF膜的各种特性最好,在本实验条件下,PMS/PSF膜的最高富氧率达36%。 相似文献
126.
Role for the p53 homologue p73 in E2F-1-induced apoptosis 总被引:20,自引:0,他引:20